JP4043189B2 - Method for cleaning substrate for electrophotographic photosensitive member - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate cleaning method for cleaning a substrate before forming a photosensitive layer on the surface of an aluminum cylindrical substrate for an electrophotographic photoreceptor.
[0002]
[Prior art]
An electrophotographic photosensitive member is produced by applying a coating solution containing a photosensitive substance on the outer peripheral surface of a conductive cylindrical substrate to form a photosensitive layer on the outer peripheral surface of the substrate. When the photosensitive layer is formed, if an oil component, foreign matter or the like adheres to the substrate, the substrate is immersed in the coating solution, thereby contaminating the coating solution and deteriorating the coating solution. It becomes impossible to form the photosensitive layer.
[0003]
For this reason, it is necessary to wash the substrate before the coating liquid containing the photosensitive substance is applied to the outer peripheral surface of the substrate. Such substrate cleaning methods include cleaning methods using solvents, semi-aqueous cleaning agents, aqueous cleaning agents, and pure water, but currently there are environmental problems such as ozone layer destruction, global warming, and air pollution. In addition, since it has an adverse effect on the human body, it has shifted to the reduction or elimination of chlorinated solvents, and has shifted to the direction of cleaning the substrate using an aqueous cleaning agent or pure water.
[0004]
An aluminum cylindrical substrate (hereinafter referred to as “substrate”) for an electrophotographic photosensitive member is obtained by processing its surface by cutting, ironing, or cold drawing. However, fine wire-like burrs and the like are generated on the surface of the substrate processed by the cutting process along the circumferential cut line. In addition, fine defects exist along the length direction on the surface of the substrate processed by plastic processing due to adhesion of crust and aluminum residue.
[0005]
As a method of removing such a raised convex defect, there is a method of removing the elastic member by pressing it against the surface of the cylindrical substrate. However, even this method cannot remove all burrs.
[0006]
As a method of cleaning the oil adhering to the substrate, a method of cleaning by irradiating ultrasonic waves with an ultrasonic oscillator in a cleaning liquid is common. A high-viscosity oil used during processing adheres to the surface of the substrate obtained by ironing or cold drawing. This high viscosity oil cannot be completely removed by the method of irradiating ultrasonic waves.
[0007]
Further, the ultrasonic irradiation by the ultrasonic oscillator raises the above-described cutting burrs, plastic working crumbs, and the like, resulting in raised convex defects. As a method of preventing raised convex defects such as burrs in cutting and rusting in plastic working due to ultrasonic irradiation by an ultrasonic oscillator, the rising state is adjusted by adjusting the ultrasonic irradiation time and ultrasonic output. There is a method for preventing the convex defect. However, even this method cannot prevent all the raised convex defects.
[0008]
[Problems to be solved by the invention]
The above-mentioned problems have not been solved in cleaning the substrate that has been cut and plastic processed. Further, the surface state of the substrate subjected to cutting and plastic processing is different, and a cleaning line suitable for each application is required. Further, in recent years, when a mirror tube is used in an electrophotographic apparatus that uses single-wavelength light such as laser light as image exposure light, such as a printer or a digital copying machine, moire is generated in the image. is needed.
[0009]
Conventionally, a method of obtaining a predetermined rough surface at the time of cutting by devising a cutting bite is known. However, when the cutting bite is devised and cut in this way, the surface of the cylindrical base body has a circumferential direction. Fine defects along the length direction are generated due to adhesion of fine burrs, etc., in the form of wires along the cut lines, and surface crusts and aluminum debris generated when the cylindrical substrate is processed by plastic working. When coating is performed on the cylindrical substrate, electrode concentration occurs. In addition, a uniform photosensitive layer cannot be formed unless the high-viscosity oil adhering to the surface of the substrate subjected to plastic processing is completely removed.
[0010]
An object of the present invention is to provide a method for cleaning an aluminum cylindrical substrate for an electrophotographic photosensitive member free from defects by improving each defect of the above-described cutting / plastic processing product at once in the same line. . Another object of the present invention is to provide a method for cleaning an aluminum cylindrical substrate for an electrophotographic photosensitive member with high production efficiency, such as no need to switch cleaning equipment even when the substrate to be produced is switched.
[0011]
[Means for Solving the Problems]
The above-described problems of the present invention are solved by the following means.
That is, the present invention is, firstly, a substrate cleaning method capable of cleaning an electrophotographic photoreceptor substrate obtained by cutting or plastic processing on the same line, and a contact cleaning step of cleaning the substrate with a brush together with a cleaning liquid. And after the contact cleaning step, a cleaning step comprising ultrasonic cleaning in which the substrate is cleaned by immersing the substrate in an aqueous cleaning solution to which ultrasonic vibration is applied, and water or pure water is added after the cleaning step. A rinsing step for removing the aqueous detergent component attached to the substrate by using, and after the rinsing step, the substrate is immersed in warm pure water and heated, and then the substrate is lifted from the warm pure water to dry the warm pure water adhered to the substrate. The main feature is a method for cleaning a substrate for an electrophotographic photoreceptor comprising a drying step.
[0012]
Second, in the contact cleaning process using the first brush, when the brush is brought into contact with the inner and outer peripheral surfaces of the workpiece and rotated, the outer brush and the base are rotated in the same direction, and the inner brush is the outer brush and the base. And a method of cleaning the substrate for an electrophotographic photoreceptor in the opposite direction.
[0013]
Third, in the contact cleaning step using the first or second brush, when rotating the brush while contacting the inner and outer peripheral surfaces of the workpiece, the peripheral speed is set to 10 m / min to 50 m / min. It is characterized by a method for cleaning a body substrate.
[0014]
Fourth, the electrophotographic photoreceptor substrate cleaning method is characterized in that the ultrasonic frequency in the first ultrasonic cleaning step is 100 kHz or more.
[0015]
Fifth, the method for cleaning a substrate for an electrophotographic photoreceptor, wherein the ultrasonic irradiation time in the fourth cleaning step is 30 seconds or more and 120 seconds or less.
[0016]
Sixth, there is provided a method for cleaning a substrate for an electrophotographic photosensitive member, wherein in the rinsing step of the first cleaning step, water or pure water is showered on the substrate, and then the substrate is immersed in water or pure water to contact bubbles. Features.
[0017]
Seventhly, in the shower of the first or sixth rinsing step, there is provided a method for cleaning a substrate for an electrophotographic photosensitive member, wherein the pressure when spraying the shower on both the inner and outer surfaces of the substrate is 0.2 MPa or more and 1.5 MPa or less. Features.
[0018]
Eighth, the electrophotographic photosensitive member substrate cleaning method is characterized in that the shower flow rate per substrate in the first, sixth or seventh rinsing step is 1 L or more and 3 L or less.
[0019]
Ninth, the rinsing step of generating bubbles in the sixth cleaning step is characterized by a method for cleaning an electrophotographic photosensitive member substrate using compressed air, blower air, or pump air as a bubble source.
[0020]
Tenth, the method of cleaning a substrate for an electrophotographic photosensitive member, wherein the size of the bubbles in the sixth or ninth rinsing step is φ5 mm or more and φ100 mm or less.
[0021]
Eleventh, the electrophotographic photoreceptor substrate cleaning method is characterized in that the air flow rate in the first, ninth, or tenth rinsing step is 60 NL / min or more and 80 NL / min or less.
[0022]
Twelfth, the electrophotographic photosensitive member substrate cleaning method is characterized in that, in the drying step in the first cleaning step, the pure water temperature is 70 ° C. or higher and 95 ° C. or lower.
[0023]
Thirteenthly, in the first or twelfth drying step, a method for cleaning an electrophotographic photoreceptor substrate having a specific resistance of warm pure water of less than 1 MΩ · cm is characterized.
[0024]
Fourteenth, it is characterized in that in the first, twelfth or thirteenth drying step, the substrate for electrophotographic photosensitive member is cleaned at a speed of lifting the substrate from warm pure water of 20 mm / sec or less.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
The present invention relates to a method for cleaning an electrophotographic photoreceptor substrate that can clean an electrophotographic photoreceptor substrate obtained by cutting, ironing, or cold drawing without causing coating film defects in the photosensitive layer on the same line. is there.
Embodiments of the present invention will be described below with reference to the drawings. First, contact cleaning 11 using a brush is performed. In this contact cleaning 11, a cylindrical brush is brought into contact with the inner and outer peripheral surfaces of the substrate. The brush used has a brush shape as shown in FIG. The pile of the brush at this time was made of nylon, and the pile diameter was set to φ0. 0 in consideration of easy removal of raised convex defects and the difficulty of scratching the cylindrical substrate surface. Use 2 mm.
[0026]
The cleaning device to which the brush is attached uses a cleaning device having a mechanism for rotating the brush and the cylindrical substrate. First, the cylindrical substrate held by the holder (FIG. 2-b) is lowered and inserted into the inner surface cleaning brush (FIG. 2-a) installed in the cleaning apparatus. The cylindrical base is rotated by rotating the holding jig while holding the base. The inner surface cleaning brush is rotated in the opposite direction. As a result, the cylindrical base and the inner surface brush contact each other. In this state, the rotated outer surface brush (FIG. 2-c) is brought into contact with the outer surface of the cylindrical substrate. At this time, by making the rotation direction of the brush and the cylindrical base body the same direction, the contact portions of the cylindrical base body and the brush move in opposite directions, and the ability to remove convex defects, and the cylinder The ability to remove oil stains and foreign matters adhering to the substrate surface is improved and good. If the rotation direction is other than this, the cleaning efficiency is lowered.
[0027]
The rotational speed of the cylindrical base and the brush is defined by the peripheral speed of the contact surface between the cylindrical base and the brush. The peripheral speed of the contact surface between the cylindrical substrate and the brush is preferably 10 m / min or more and 50 m / min or less. When it is 10 m / min or less, it becomes difficult to remove the raised convex defects. Further, if it is 50 m / min or more, the surface of the aluminum cylindrical substrate for an electrophotographic photoreceptor is likely to be damaged. This time, it experimented at 40 m / min.
[0028]
In this experiment, kerosene was used for the purpose of washing high-viscosity oil between the cylindrical base and the above-mentioned brush when washing with the above-described washing machine, but is not particularly limited thereto. . By bringing the brush into contact with the cylindrical base as described above, fine wire-like burrs along the circumferential cutting lines in the cutting process of the cylindrical base, and of the crumbs and aluminum scrap generated by plastic processing It is possible to remove raised convex defects such as fine defects along the length direction caused by adhesion or the like, and high-viscosity oil.
[0029]
In the next ultrasonic cleaning step 12, the substrate is immersed in an aqueous cleaning solution and irradiated with ultrasonic waves. In this ultrasonic cleaning, kerosene remaining on the substrate is completely removed. First, regarding the frequency of the ultrasonic oscillator, high-frequency ultrasonic waves are used to prevent rising convex defects on the surface of the cylindrical substrate. Specifically, an ultrasonic oscillator having a frequency of 100 KHz or more is used. When it is less than 100 KHz, along the length direction generated by the adhesion of the fine burrs in the wire shape along the circumferential cutting line in the cutting process of the cylindrical base body, the crumbs or the aluminum residue generated by the plastic processing, etc. A minute defect or the like is struck by an ultrasonic wave and becomes a raised convex defect. The ultrasonic irradiation method is not particularly limited. In this experiment, 133 KHz ultrasonic waves were used.
[0030]
When cleaning is performed using ultrasonic waves of 100 KHz or higher, the cleaning time is required to be 30 seconds or more and 120 seconds or less. In this experiment, 60 seconds was used.
[0031]
In the next shower cleaning step 13, water is sprayed to the inner peripheral surface and the outer peripheral surface of the substrate at a pressure of 0.2 MPa to 1.5 MPa. When the pressure is 0.2 MPa or less, the rinsing force is small. When the pressure is 1.5 MPa or more, the rinsing force is not changed and water is wasted, and the amount of waste water treatment is increased. In this experiment, 1 MPa was adopted.
[0032]
In this step, most of the aqueous cleaning liquid adhering to the previous step is washed away. Although it is possible to completely remove the aqueous cleaning solution only by the next bubbling cleaning step 14, this water cannot be drained unless it is treated with activated carbon or the like. Therefore, since the amount of treated water is increased, the running cost is increased. Therefore, water shower cleaning that can be efficiently rinsed with a small amount of water is performed.
[0033]
In the next bubbling cleaning step 14, the substrate is immersed in pure water and air is jetted from below the workpiece. This air may be conventional factory compressed air, air from a blower, or air from a diaphragm pump. As a result of the test, it has been found that the bubble size is preferably in the range of φ5 mm to φ100 mm. This experiment was performed under the following conditions.
・ Bubble size: φ30mm
・ Air flow rate: 70NL / min
As a result, the aqueous cleaning agent adhering to the substrate could be completely removed.
[0034]
In the next warm pure water drying 15, the substrate is immersed in heated pure water, and after the drum is heated to the pure water temperature, the substrate is pulled up at a constant speed. Thereby, the pure water adhering to the outer peripheral surface of the base body is evaporated and drained. The pure water temperature at this time is preferably 70 ° C. or higher and 95 ° C. or lower. In the case of 70 ° C. or lower, it has been confirmed that dry spots can be formed on the substrate surface.
[0035]
When the substrate is immersed in warm pure water having a specific resistance greater than 1 MΩ · cm, a hydroxide film is easily formed on the substrate surface. This is not preferable because it affects the electrical characteristics when the photosensitive layer is formed. In addition, when the pulling rate of the substrate from the warm pure water is 20 mm / sec or more, the amount of water adhering to the substrate is large and it becomes difficult to dry. This experiment was performed under the following conditions.
・ Warm pure water temperature: 80 ℃
・ Warm pure water resistivity: 0.6MΩ ・ cm
-Substrate pulling speed: 10 mm / sec
[0036]
【The invention's effect】
As described above, the invention of claim 1 is a substrate cleaning method capable of cleaning an electrophotographic photoreceptor substrate obtained by cutting or plastic processing on the same line, and includes a contact cleaning process using a brush, ultrasonic cleaning Since it comprises a process, a rinsing process for removing aqueous detergent components, and a warm pure water drying process, a uniform and defect-free photosensitive layer can be formed by applying the photosensitive layer on the obtained substrate.
[0037]
According to a second aspect of the present invention, in the cleaning method, when the brush is brought into contact with the inner and outer peripheral surfaces of the workpiece and rotated, the outer brush and the base are rotated in the same direction, and the inner brush is opposite to the outer brush and the base. Therefore, the contact portion between the cylindrical base body and the brush moves in the opposite directions, and the ability to remove convex defects and the ability to remove oil stains and foreign matters adhering to the cylindrical base surface are further improved. To do. If the rotation direction is a combination other than this, the cleaning efficiency is lowered.
[0038]
According to the invention of claim 3, in the cleaning method, when the brush is brought into contact with the inner and outer peripheral surfaces of the workpiece and rotated, the peripheral speed is set to 10 m / min or more and 50 m / min or less. Defects can be easily removed and the surface of the cylindrical substrate is hardly damaged.
[0039]
Since the ultrasonic frequency of the cleaning step is 100 kHz or more in the above cleaning method, the fine wire-like burrs in the circumferential direction and the fine defects in the length direction of the substrate are ultrasonic. It can be prevented from being raised and becoming a raised convex defect.
[0040]
According to the fifth aspect of the present invention, since the ultrasonic irradiation time in the cleaning step is 30 seconds or more and 120 seconds or less in the cleaning method, good cleaning can be performed by ultrasonic waves of 100 KHz or more.
[0041]
In the cleaning method according to the sixth aspect of the present invention, since the substrate is immersed in water or pure water after the water or pure water is showered on the substrate and the bubbles are brought into contact with the substrate, the aqueous cleaning solution adhered in the previous step is sufficiently removed. Can be dropped.
[0042]
In the invention of claim 7, in the shower of the rinsing step, the pressure when spraying the shower onto the inner and outer surfaces of the base is 0.2 MPa or more and 1.5 MPa or less, so the rinsing force is not reduced, and Don't waste water.
[0043]
According to the eighth aspect of the present invention, since the shower flow rate per substrate in the shower in the rinsing step is 1 L or more and 3 L or less, an appropriate amount and effective rinsing can be performed.
[0044]
The invention of claim 9 is very effective for injecting air from below the workpiece because compressed air, blower air, and pump air are used as the bubble source in the rinsing step for generating the bubbles.
[0045]
In the invention of claim 10, since the size of the bubbles is not less than φ5 mm and not more than φ100 mm, the removal of the aqueous cleaning agent adhering to the substrate is excellent.
[0046]
According to the eleventh aspect of the invention, since the air flow rate in the rinsing step is 60 NL / min or more and 80 NL / min or less, the removal of the aqueous cleaning agent attached to the substrate is excellent.
[0047]
According to the twelfth aspect of the present invention, since the pure water temperature in the drying step is set to 70 ° C. or higher and 95 ° C. or lower, no dry spots are formed on the substrate surface, and the pure water adhering to the outer peripheral surface of the substrate is well drained. can do.
[0048]
According to the thirteenth aspect of the present invention, since the specific resistance of warm pure water in the drying step is smaller than 1 MΩ · cm, it is possible to prevent the formation of a hydroxide film that is easily formed on the surface of the substrate and does not adversely affect the electrical characteristics of the photosensitive layer.
[0049]
In the invention of claim 14, since the pulling speed of the substrate from the warm pure water in the drying step is 20 mm / sec or less, the amount of water adhering to the substrate is not increased and the drying is not made difficult.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration (step) of a cleaning tank in a cleaning method of the present invention.
FIG. 2 is a diagram showing the shape of a brush.
FIG. 3 is a diagram showing a cleaning state of a substrate by a contact cleaning machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Contact cleaning process with brush 12 Ultrasonic cleaning process 13 Shower cleaning process 14 Bubbling cleaning process 15 Warm pure water drying process a Inner surface cleaning brush b Holder c Outer surface brush d Cylindrical substrate

Claims (13)

A substrate cleaning method capable of cleaning an electrophotographic photoreceptor substrate obtained by cutting or plastic processing on the same line, a contact cleaning step of cleaning the substrate with a brush together with a cleaning liquid, and after the contact cleaning step, A cleaning step comprising ultrasonic cleaning in which the substrate is immersed in an aqueous cleaning solution to which sonic vibration is applied, and cleaning the substrate; after the cleaning step, water or pure water is showered on the substrate; contacting the cell is immersed base body in water, and rinsing step for removing the water-based detergent component adhering to the substrate, said rinse after step, warm pure water to said substrate after heating by immersing the substrate in hot deionized water A method of cleaning a substrate for an electrophotographic photoreceptor, comprising a drying step of drying hot pure water that has been pulled up from the substrate and adhered to the substrate.   2. The method for cleaning a substrate for an electrophotographic photoreceptor according to claim 1, wherein when rotating the brush in contact with the inner and outer peripheral surfaces of the workpiece, the outer brush and the substrate are rotated in the same direction, and the inner brush is the outer brush. A method for cleaning a substrate for an electrophotographic photosensitive member, characterized in that the direction is opposite to the substrate.   3. The method for cleaning a substrate for an electrophotographic photosensitive member according to claim 1 or 2, wherein the peripheral speed is set to 10 m / min or more and 50 m / min or less when the brush is rotated while contacting the inner / outer peripheral surface of the workpiece. A method for cleaning a substrate for an electrophotographic photosensitive member.   2. The method for cleaning a substrate for an electrophotographic photosensitive member according to claim 1, wherein the ultrasonic frequency in the ultrasonic cleaning step is 100 kHz or more.   5. The method for cleaning an electrophotographic photosensitive member substrate according to claim 4, wherein the ultrasonic irradiation time is 30 seconds or more and 120 seconds or less. 6. The method for cleaning a substrate for an electrophotographic photosensitive member according to claim 1, wherein, in the rinsing step, a pressure when spraying a shower on the inner and outer surfaces of the substrate is 0.2 MPa or more and 1.5 MPa or less. A method for producing a substrate for an electrophotographic photosensitive member. 7. The method for cleaning an electrophotographic photoreceptor substrate according to claim 1, wherein a shower flow rate per substrate is 1 L or more and 3 L or less in the rinsing step. Cleaning method. 7. The method for cleaning an electrophotographic photosensitive member substrate according to claim 6, wherein compressed air, blower air, or pump air is used as a bubble source. 9. The method for cleaning an electrophotographic photosensitive member substrate according to claim 6, wherein the size of the bubbles is not less than φ5 mm and not more than φ100 mm. . 10. The method for cleaning an electrophotographic photosensitive member substrate according to claim 6, wherein an air flow rate is 60 NL / min or more and 80 NL / min or less. 2. The method for cleaning a substrate for an electrophotographic photosensitive member according to claim 1, wherein the temperature of pure water in the drying step is 70 ° C. or higher and 95 ° C. or lower. 12. The method for cleaning an electrophotographic photosensitive member substrate according to claim 1, wherein the specific resistance of warm pure water in the drying step is less than 1 MΩ · cm. 13. The electrophotographic photosensitive member substrate according to claim 1, wherein the substrate is pulled up from warm pure water in the drying step at a rate of 20 mm / sec or less. Cleaning method.

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