JPH09218525A - Apparatus for production of electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the influence of unequal gaseous flow on coating films and to eliminate the variation in a coating film distribution by mounting a plate for preventing the interference of gaseous flow near the upper part of a coating tank. SOLUTION: The plate 8 for preventing the interference of the gaseous flow prevents the influence of the gaseous flow on the outside of the plate from spreading into the plate 8 for preventing the interference of the gaseous flow. Of the flow of the gas released from or inhaled into the vent holes 2, the flow spreading downward is regulated by a gaseous flow control plate 9. The dip coating of a substrate 3 is executed by lowering a substrate holding jig 1 in the state of holding the substrate 3 and immersing the substrate 3 into the coating liquid 5 in the coating tank 4, then rising the substrate holding jig 1. In case the coating liquid flow over from the coating tank 4 during the dip coating, the coating liquid is once received in a liquid receiver 6 and is delivered to a return side. The release or inhalation of the gas from or into the vent holes 2 is executed for the specified time in either state during the descending action, during the immersion after the end of the descending or during the ascending or during the combination thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoconductor manufacturing apparatus, and more particularly, to an improvement of a dip coating apparatus for manufacturing a photosensitive layer forming liquid of a plurality of cylindrical substrates for manufacturing an electrophotographic photoconductor. .

[0002]

2. Description of the Related Art The dip coating method is widely known as a typical method for coating a coating material for an electrophotographic photosensitive layer on the outer peripheral surface of a cylindrical substrate. However, this dip coating method employs a means of vertically pulling up the cylindrical substrate immersed in the coating material (photosensitive layer forming liquid), so that the upper part of the coating film (photosensitive layer film) applied by the dip coating method is used. In this case, a portion (sag portion) where the film thickness is smaller than the stable film thickness is generated. Since the characteristics of the photosensitive member in this portion do not satisfy the standard, various methods for shortening the sagging portion have been studied.

As a means for shortening the sagging portion,
For example, (1) an intake / exhaust port is provided above the liquid surface of the coating tank to reduce the vapor concentration before the substrate is pulled up (JP-A-59).
No. 127049), and (2) an intake / exhaust port is provided in the upper part of the coating tank to prevent the accumulation of solvent vapor (JP-A-59-174843).
(3), (3) When coating the substrate, an air stream is applied to the substrate with an air jet in the pulling direction (JP-A-59-22).
5771), and (4) when pulling up the substrate, a horizontal airflow is generated above the tank (JP-A-1-107874). However, in these methods, a ventilation means for reducing the solvent concentration must be provided in the upper part of the coating tank, and the most effective method for shortening the sagging portion is the contact between the substrate and the photosensitive layer coating liquid surface. It is difficult to adjust the solvent vapor concentration near the liquid part.

As one of the methods for shortening the sagging portion, a ventilation hole is provided in a substrate holding jig used for dip coating,
A method is known in which gas is released or inhaled through the ventilation hole. However, if it is attempted to apply the photosensitive layer forming liquid to a plurality of substrates at the same time using this method, the flow of gas released or inhaled from the ventilation holes provided in each substrate holding jig interferes with each other and the immersion is performed. In the coating apparatus, there are portions where the air flow has a strong influence and portions where the influence of the air flow is weak, and the distribution of the mutual film thickness varies on the substrate.

[0005]

DISCLOSURE OF THE INVENTION It is an object of the present invention, in a dip coating apparatus capable of simultaneously coating a photosensitive layer coating material on a plurality of cylindrical substrates, gas is supplied from a ventilation hole provided in a substrate holding jig. When coating is performed by discharging or inhaling, the influence on the coating film due to uneven air flow generated in the dip coating device or in its upper part and / or its periphery is eliminated, and between the electrophotographic photoreceptors coated at the same time. An object of the present invention is to provide an apparatus for eliminating the variation in film thickness distribution.

[0006]

The present inventors have studied from various angles about an apparatus capable of forming a photosensitive coating film having a uniform thickness on the surfaces of a plurality of cylindrical substrates. It was found that the above-mentioned problems can be achieved by disposing a new airflow interference prevention plate and / or airflow rectifying plate at an appropriate position. The present invention has been made based on this.

Therefore, according to the present invention, (1) in a dip coating apparatus capable of simultaneously coating a photosensitive layer coating material on a plurality of cylindrical substrates, an air flow interference prevention plate is provided near the upper portion of the coating tank. (2) A dip coating apparatus capable of simultaneously coating the photosensitive layer coating material on a plurality of cylindrical substrates, wherein an air flow is provided in the middle of the coating tank. (3) An electrophotographic photoconductor manufacturing apparatus characterized in that a control plate is attached, (3) In the above (1), an airflow control plate is further attached to an intermediate portion of the coating tank. A manufacturing apparatus is provided.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1, 2 and 3 show three examples of the device of the present invention. FIG. 1 shows the device (1) and FIG. 2 shows the device (2). In addition, FIG. 3 corresponds to the device (3). However, the embodiment of the present invention is not limited to the examples of FIG. 1, FIG. 2 and FIG.
The present invention can also be applied to a modified electrophotographic photoreceptor manufacturing apparatus without changing the gist of the present invention. For example, the present invention can effectively work even for a dip coating apparatus that does not have an independent coating tank. .

In each drawing, 1 is a substrate holding jig, 2 is a ventilation hole, 3 is a substrate, 4 is a coating tank, 5 is a photosensitive layer coating solution, and 6 is a coating solution.
Is a liquid receiver, 7 is a lid, 8 is an airflow interference prevention plate, and 9 is an airflow control plate. In these figures,
The substrate holding jig 1 can move up or down in a substantially vertical direction while holding the substrate 3. Further, the ventilation holes 2 are distributed in a cylindrical shape on the surface of the gas holding jig 1 and are set so that the gas can be uniformly discharged or sucked in the entire circumferential direction.

The airflow interference preventing plate 8 which constitutes the main part of the device of the present invention is made of a metal material such as stainless steel or aluminum, or a plastic material such as polyethylene or polypropylene, and has a central axis of the base body 3. Has a substantially cylindrical shape, and the entire cylindrical surface or a certain range (for example, a range above the upper end position of the coating tank 4) is used as a mesh or pores are provided. The size of the mesh is JIS Z88
The nominal size of 01 is about 20 μm to 600 μm, and the pores are about 20 μmφ to 600 μmφ. The airflow interference part stop plate 8 is provided near the upper part of the coating tank 4.

Further, the air flow control plate 9 constituting the main part of the device of the present invention is made of a material such as a metal material such as stainless steel or aluminum, and can control the air flow such as mesh, pores or a combination thereof. The structure is shown. The airflow control plate 9 is provided in the middle part of the coating tank 4. The size of the mesh provided on the airflow control plate 9 is JI.
A nominal size of S Z8801 of about 500 μm to 5.6 mm is suitable, and pores of about 0.5 mmφ to 5 mmφ are suitable.

Since the base body 3 is dipped in the coating liquid and then pulled up from the coating liquid, the base body 3 is locked to the base body holding jig 1. A ventilation hole 2 is formed in the lower stage of the substrate holding jig 1, and the flow of gas released or sucked in from the ventilation hole 2 spreads outward from the ventilation hole 2 distributed in a cylindrical shape. The flow is blocked or weakened by the prevention plate 8. The airflow interference prevention plate 8 also prevents the influence of the airflow outside the plate from spreading into the airflow interference prevention plate 8. Of the flow of gas discharged or sucked in from the ventilation hole 2, the flow spreading downward is rectified by the airflow control plate 9. Here, the meaning of releasing the gas from the vent 2 is to control the solvent vapor concentration in the vicinity of the coating liquid surface, and the meaning of sucking the gas from the vent 2 is the gas from the vent 2. This is to control the solvent vapor concentration in the vicinity of the coating liquid surface, as in the case of discharging the.

The dip coating of the substrate 3 is carried out by lowering the substrate holding jig 1 with the substrate 3 held until the state shown in FIGS. 1, 2 and 3 is obtained, and the coating solution for the photosensitive layer in the coating tank 4 is applied. After the substrate 3 is dipped in the substrate 5, the substrate holding jig 1 is lifted up. If any coating liquid overflows from the coating tank 4 during dip coating, the coating liquid 6
After receiving it once, it is sent to the return side. Vent 2
The release or inhalation of gas from the chamber is performed for a certain period of time during the lowering operation, the immersion after the lowering is completed, the rising, or a combination thereof.

[0014]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

Example 1 (Formation of Undercoat Layer) Soluble nylon (Toray: Alamine CM-8000) 5 parts by weight A coating solution of 95 parts by weight of methanol was added to a cylindrical aluminum substrate (80 mm).
(φ, wall thickness 1 mm) was dipped, pulled up and dried at 100 ° C. for 10 minutes to form an undercoat layer having a thickness of about 0.3 μm. (Formation of Charge Generation Layer) 10 parts by weight of charge generation material represented by the following structural formula

Embedded image A mixture of 7 parts by weight of polyvinyl butyral and 145 parts by weight of tetrahydrofuran was milled with a ball mill for 72 hours, and 200 parts by weight of cyclohexanone was added thereto and dispersed for 1 hour. The liquid after completion of dispersion was further diluted and adjusted with cyclohexanone to prepare a charge generation layer coating liquid having a solid content of 2.0 wt%. The aluminum-made cylindrical substrate on which the undercoat layer was formed was dip-coated on this charge generation layer coating solution and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of about 0.1 μm.

(Formation of Charge Transport Layer) 7 parts by weight of charge transport material represented by the following structural formula

Embedded image A mixture of 10 parts by weight of polycarbonate (manufactured by Teijin Ltd., Panlite C-1400) and 83 parts by weight of tetrahydrofuran was used as a charge transport layer coating liquid, and the aluminum cylindrical substrate on which the charge generation layer was formed was prepared using the mixture. The substrate was held by a substrate holding jig having pores, and coating was performed using the dip coating device shown in FIG. The number of substrates to be simultaneously coated was set to 9, and one coating tank was provided for each substrate. Arrangement of coating tank is 3 rows x 3
Columns. After descending and immersing in the charge transport layer coating solution,
A waiting time of 3 seconds was provided until the substrate was raised, and air was discharged from the ventilation holes during this time. A sintered resin filter (FD-40 manufactured by Kaken Co., Ltd.) was used as the ventilation hole.
The amount of air released was 100 ml / sec. After stopping the release of air and eliminating the pressure accumulation of air inside the ventilation filter, the substrate was raised and the charge transport layer was applied. The thickness distribution of the charge transport layer coating film on each substrate was measured at eight locations using an electronic micrometer (K-351C, manufactured by Anritsu Corporation), and the average value was obtained. Almost no difference in the film thickness distribution between the substrates was observed.

Example 2 An undercoat layer and a charge generation layer were formed on an aluminum cylindrical substrate in the same manner as in Example 1. Next, a charge transport layer was applied onto the aluminum cylindrical substrate on which the charge generation layer was formed in the same manner as in Example 1 except that the dip coating device shown in FIG. 2 was used. The state of the applied coating film of the charge transport layer was observed in the same manner as in Example 1. Almost no difference in the film thickness distribution was found between the substrates.

Example 3 An undercoat layer and a charge generating layer were formed on an aluminum cylindrical substrate in the same manner as in Example 1. Next, the charge transport layer was applied onto the aluminum cylindrical substrate on which the charge generation layer was formed, in exactly the same manner as in Example 1 except that the dip coating apparatus shown in FIG. 3 was used. The state of the applied coating film of the charge transport layer was observed in the same manner as in Example 1. Almost no difference in the film thickness distribution was found between the substrates.

Comparative Example 1 An undercoat layer and a charge generation layer were formed on an aluminum cylindrical substrate in exactly the same manner as in Example 1. Next, using the same apparatus as the dip coating apparatus of Example 1 except that the air current interference prevention plate was removed, the charge transport was performed on the aluminum cylindrical substrate on which the charge generation layer was formed in the same manner as in Example 1. The layers were applied. The state of the applied coating film of the charge transport layer was observed in the same manner as in Example 1. It was confirmed that there was a difference between the film thickness distribution of the substrate applied in the coating tank arranged in the central part and the film thickness distribution of the substrate applied in the coating tank arranged in the peripheral part.

Example 1, Example 2, Example 3, Comparative Example 1
In Fig. 4, a substrate coated in a coating tank (indicated by A in Fig. 4) in which a dip coating device is arranged in the central portion, and a coating tank in which a dip coating device is arranged in the peripheral portion (B in Fig. 4). Table 1 shows the measured values of the variation of the average value of the film thickness in the circumferential direction at the sagging portion length and the film thickness stable portion of the substrate coated with (1.

[0021]

[Table 1]

[0022]

According to the first aspect of the present invention, when a plurality of substrates are simultaneously coated, the range of the flow of gas discharged or sucked from the ventilation holes provided in the respective substrate holding jigs can be adjusted. It was possible to limit it to the vicinity of the target substrate, and to eliminate the difference in the film thickness distribution between the substrates simultaneously coated. According to the second aspect of the present invention, the downward flow of the gas discharged or sucked from the ventilation hole provided in the base jig can be reached, and the difference in the film thickness distribution between the bases coated at the same time can be eliminated. We were able to. Further, it is possible to expect an effect that air current unevenness occurs in the coating device caused by the flow of the overflowing coating liquid. According to the invention of claim 3, by combining the devices of claim 1 and claim 2, a further effect for suppressing the difference in the film thickness distribution can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view of an example of an apparatus according to the present invention.

FIG. 2 is a schematic view of another example of the device according to the present invention.

FIG. 3 is a schematic view of still another example of the apparatus according to the present invention.

FIG. 4 is a schematic view of the coating tanks arranged in 3 rows × 3 rows as seen from above.

[Explanation of symbols]

 1 Substrate holding jig 2 Vent hole 3 Substrate 4 Coating tank 5 Photosensitive layer coating liquid 6 Liquid receiver 7 Lid 8 Airflow interference prevention plate 9 Airflow control plate

Claims (3)

[Claims] 1. An electronic device characterized in that, in a dip coating apparatus capable of simultaneously coating a photosensitive layer coating material on a plurality of cylindrical substrates, an air flow interference preventing plate is attached near the upper part of the coating tank. Photoconductor manufacturing equipment. 2. An electrophotographic sensitizer characterized in that, in a dip coating apparatus capable of simultaneously coating a photosensitive layer coating material on a plurality of cylindrical substrates, an air flow control plate is attached to an intermediate portion of the coating tank. Body manufacturing equipment. 3. The electrophotographic photoconductor manufacturing apparatus according to claim 1, further comprising an airflow control plate attached near the middle portion of the coating tank.