JP3154263B2 - 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, and more particularly, to a method for continuously manufacturing an electrophotographic photosensitive member having no image defects.

[0002]

2. Description of the Related Art An electrophotographic photoreceptor is produced by forming a photosensitive layer on a support and, if necessary, a conductive layer and an intermediate layer. As a method of forming each of these layers, there is a method of directly attaching a substance to the support surface by a method such as vacuum deposition, sputtering, or CVD as in the example of the selenium photoreceptor and the amorphous silicon photoreceptor.
A method of preparing a coating solution in which a binder resin or the like is dispersed or dissolved in a solvent and attaching the coating solution to the surface of the support by a coating means is excellent in mass productivity and production cost. In recent years, electrophotographic photoreceptors, especially OPC (organic photoreceptors) Widely used in the manufacture of

After the coating solution is applied and the heating and drying are completed , the coating solution is cooled and the process proceeds to the next step. As a cooling method, there are a natural cooling method by simply leaving it to stand, a cooling by blowing air, and the like.

[0004]

However, the conventional cooling method has the following problems. 1) In natural cooling, it takes a long time to cool the support, so that dust and the like adhere to the coated and dried surface, causing coating defects in the next coating step. 2) In the air cooling, the air is blown so that the dust rises so much that the dust adheres to the coating / drying surface and causes coating defects in the next coating process. 3) In any of the conventional cooling methods, when the thickness of the support is large and the heat capacity is large, there is a problem that the cooling rate of the support is slow and the time required for the cooling step is long, so that the production efficiency is not improved.

Further, when high sensitivity and high image quality are required for an electrophotographic photoreceptor, the photoreceptor often has a multi-layer structure in which functions are separated from each other. A layer for controlling charge injection properties, preventing irregular reflection of light, and complementing defects of the support. Intermediate layer: a layer located between the photosensitive layer and the support or between the photosensitive layer and the conductive layer and functioning as a barrier layer against charge injection. Charge generation layer: A layer that generates charges upon exposure. Charge transport layer: A layer in which charges generated in the charge generation layer are transported.

In the case of such a multilayer structure, a low coating defect rate is required for each layer. Therefore, in the conventional cooling method, dust adhered during cooling has been a problem in securing a good non-defective product rate. Furthermore, when each layer is continuously applied, it is necessary to cool down in as short a time as possible in order to operate the production line efficiently.

[0007]

[0008]

It is an object of the present invention to provide a method for stably producing a high-quality electrophotographic photoreceptor free of coating defects and image defects over a long period of time by solving the above problems.

[0010]

That is, the present invention relates to a method for producing an electrophotographic photosensitive member comprising a conductive support and a plurality of layers including a photosensitive layer laminated on the conductive support . Fewer layers
Both layers have elasticity after applying coating liquid and drying by heating
Pressurizes and feeds liquid into a cooling device made of material
The cooling device is expanded by expanding the cooling device.
It is contacted to the support due to cooling the said support
A method for producing a photoreceptor, and forming Te.

[0011]

Hereinafter, the present invention will be described.

[0013] As the cooling means used in the present invention is a device for cooling the surface not used for image formation of the support is contacted to cool the support, thermally conductive Examples of the material of the apparatus for contacting Good and resilient materials include, for example , silicone rubber, fluorine rubber and the like . Ma
In order to improve the contact with the support ,
After inserting the body inside the support, the outer shape of the device expands and expands
Add a mechanism to do this.

As an example of a method of cooling the device to be brought into contact with the support, a method of incorporating a cooling section of a heat pump inside the device can be mentioned. When it is necessary to sufficiently control the temperature stability of the cooling device, a cooling medium may be circulated inside and cooled by a heat exchanger. It is preferable to control the surface temperature of the device to be brought into contact with the support so that the surface temperature of the support becomes a target temperature, and also to keep the surface temperature of the support unchanged during continuous production. Similarly, it is preferable to control the temperature distribution so that the surface temperature of the support falls within the target temperature range in any part, and therefore the surface temperature of the device to be contacted may be divided into several parts and controlled. Good.

[0015]

The method of producing an electrophotographic photosensitive member of the present invention, in which a cooled device is brought into contact with the support of the photosensitive member to cool the support, can be used in combination with other cooling methods (for example, air cooling, natural cooling). It is possible.

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

As the material of the support used in the present invention, a material having good thermal conductivity is suitable, and examples thereof are as follows. Metals such as aluminum, copper, nickel, and silver or alloys thereof; conductive metal oxides such as antimony oxide, indium oxide, and tin oxide; carbon fiber; carbon black; .

The coating liquid used in the present invention is as follows.

Examples of the coating solution used for coating the conductive layer include metal powders such as aluminum, copper, nickel and silver; conductive metal oxides such as antimony oxide, indium oxide and tin oxide; polypyrrole, polyaniline, and polymer electrolyte Conductive materials such as carbon fiber, carbon black, and graphite powder; or conductive powders whose surfaces are coated with these conductive materials; and acrylic resins, polyester resins, polyamide resins, and polyvinyl acetate resins. Thermoplastic resins such as polyurethane resins, polycarbonate resins and polyvinyl butyral resins; thermosetting resins such as polyurethane resins, phenolic resins and epoxy resins; binder resins such as photocurable resins; alcohols such as methanol, ethanol, butanol and isopropyl alcohol; Ketones such as acetone, acetone, methyl isobutyl ketone and cyclohexanone; ethers such as diethyl ether and tetrahydrofuran; esters such as ethyl acetate and propyl acetate; hydrocarbons such as normal hexane and toluene; and other suitable solvents. And additives to which necessary additives are added.

Examples of the coating solution for the intermediate layer include gelatin, ethylene / acrylic acid copolymer, nitrocellulose resin, polyamide resin, polyvinyl alcohol resin,
Alcohols such as methanol, ethanol, butanol, isopropyl alcohol and the like; resins such as polyvinyl alcohol resin; ketones such as methyl ethyl ketone, acetone and methyl isobutyl ketone; dissolved in a suitable solvent; One.

The photosensitive layer may have a single-layer structure or a laminated structure in which a charge generation layer and a charge transport layer are separated in function.

Examples of the coating solution for the charge generation layer of the laminated photoreceptor include azo pigments such as Sudan red and chlordian blue; phthalocyanine pigments such as copper phthalocyanine and titanyl phthalocyanine; quinone pigments such as anthranthrone; Pigment and other charge generating substances and thermoplastic resins such as acrylic resin, polyester resin, polyamide resin, polyvinyl acetate resin, polycarbonate resin, polyvinyl butyral resin, polyvinyl benzal resin; thermosetting of polyurethane resin, phenol resin, epoxy resin, etc. Binder resins such as resins are converted to alcohols such as methanol, ethanol, butanol and isopropyl alcohol; keto resins such as methyl ethyl ketone, acetone, methyl isobutyl ketone and cyclohexanone. Ethers such as diethyl ether and tetrahydrofuran; esters such as ethyl acetate and propyl acetate; hydrocarbons such as normal hexane and toluene; those dispersed in other suitable solvents; and, if necessary, additives. And the like.

Examples of the coating solution for the charge transport layer include charge transport materials such as hydrazone compounds, stibene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triarylmethane compounds, and acrylic resins, polyester resins, and the like. Thermoplastic resins such as polyarylate resin, polyvinyl chloride resin, polycarbonate resin, polyvinyl butyral resin, and polymethacrylate resin; binder resins such as polyurethane resin, phenol resin, and epoxy resin; methanol, ethanol, butanol Alcohols such as isopropyl alcohol and isopropyl alcohol; ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone and cyclohexanone; ethers such as diethyl ether and tetrahydrofuran; acetic acid Esters such as tyl and propyl acetate; hydrocarbons such as normal hexane, petroleum ether and toluene; halogenated hydrocarbons such as monochlorobenzene and dichloromethane, and those dispersed in other suitable solvents, and additives as required. Is added. Further, an example of a coating solution in which a conductive polymer is dissolved in a solvent is also included. Further, a material that reduces wear, such as Teflon powder, may be dispersed.

Further, the coating method used in the production method of the present invention can be applied not only to the conductive layer, the intermediate layer, the charge generation layer and the charge transport layer of the electrophotographic photosensitive member but also to other layers such as an overcoat layer. .

As the solvent used in the present invention, a solvent having good solubility in the binder resin in the coating liquid, dispersibility in the pigment and coating properties is selected.

In preparing the coating solution for the electrophotographic photosensitive member used in the present invention, simple stirring and mixing may be used, but if necessary, a dispersing means such as a ball mill, a roll mill, and a sand mill is used.

The coating method used in the present invention includes dip coating, spray coating, roll coater coating, and gravure coater coating.

The method for producing an electrophotographic photosensitive member of the present invention can be applied to the production of photosensitive drums used in general electrophotographic devices such as copiers, laser printers, LED printers, and liquid crystal shutter printers.

[0036]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to specific examples. Embodiment 1 FIG. 1 shows an example of a cooling device used in the present invention. The cooling water 11 is supplied to the contact cooling device 1 from the cooling water tank 2 by the pump 3. The cooling water tank 2 is controlled by a cooler 4 so that the water temperature becomes constant. The contact cooling device 1 is made of silicon rubber, and has a structure in which the internal pressure can be adjusted by a pressure regulating valve 5, so that the whole can be expanded or contracted. After the application is completed, the support (aluminum cylinder) 6 removes the application liquid adhering to the inner surface of the cylinder by peeling. After drying, the support 6 is transported onto the contact cooling device 1 by a transporting means including a cylinder chucking jig 7, an up-down telescopic arm 8, a transport unit 9 and a transport rail 10, and inserted into the contact cooling device. The pressure in the contact cooling device is adjusted by the pressure regulating valve to expand the contact cooling device. After the heating and cooling are completed, the pressure inside the contact cooling device is adjusted again and contracted, and then conveyed by the conveying means to the next step.

Next, an electrophotographic photosensitive member is manufactured. 10%
2000 parts of conductive titanium oxide coated with tin oxide containing antimony oxide, 2500 parts of phenolic resin, 2000 parts of methylcellosolve, 500 parts of methanol
The resulting mixture was dispersed in a sand mill using glass beads for 2 hours to prepare a coating solution for a conductive layer.

Aluminum cylinder (φ120mm × 3
The above-mentioned coating material for a conductive layer was applied by dip coating on a 60 mm thick wall with a thickness of 5 mm, and dried at 160 ° C. for 20 minutes by a drier. After the drying was completed, it was cooled for 10 minutes by the cooling device shown in FIG. The temperature of the cooling water is 15 ° C and the surface temperature of the cooling device is 18
° C, and the surface temperature of the support after cooling was completed was 23 ° C. The thickness of the conductive layer was 20 μm.

Next, 6,1000 parts of reprecipitated and purified N methoxymethylated nylon, 250 parts of 6,12,66,610 copolymerized nylon were dissolved in 5000 parts of methanol and 5000 parts of butanol, and this solution was subjected to an opening diameter of 0 parts. The mixture was filtered through a 0.5 μm filter to remove residual undissolved matter, dust and the like, thereby preparing a coating solution for the intermediate layer. The coating liquid for an intermediate layer was dip-coated on an aluminum cylinder coated with a conductive layer, and dried at 95 ° C. for 7 minutes by a drier. After the drying was completed, it was cooled for 7 minutes by the cooling device shown in FIG. Cooling water temperature is 1
The temperature of the cooling device was 5 ° C, the surface temperature of the cooling device was 18 ° C, and the surface temperature of the support after cooling was completed was 23 ° C. The thickness of the intermediate layer was 0.50 μm. The above steps are repeated to continuously apply the conductive layer and the intermediate layer coated aluminum cylinder to 1000.
I made this book. The 1,000 coated aluminum cylinders were visually inspected to separate defective products having coating defects. As a result, 31 defective coated aluminum cylinders were found.

Example 2 400 parts of a disazo pigment having the following structural formula:

[0041]

Embedded image

200 parts of polyvinyl butyral resin (butyral conversion rate: 68%, average molecular weight: 24000) and 5,000 parts of cyclohexanone were dispersed for 14 hours by a sand mill using φ1 mm glass beads, and tetrahydrofuran 5
000 parts was added, and the solution was further centrifuged (7000
(rpm, 30 minutes) to remove bead residue, dust and the like, and then filtered through a 5.0 μm filter having an opening diameter to remove residual undissolved matter, dust and the like, thereby preparing the above-mentioned coating solution for the charge generation layer. A good aluminum cylinder coated with an intermediate layer in Example 1 (φ120 mm × 360 mm, wall thickness 5 m)
m) was coated with the above-mentioned coating solution for a charge generation layer by dip coating, and dried at 85 ° C. for 7 minutes by a drier. After the drying was completed, it was cooled for 7 minutes by the cooling device shown in FIG. Cooling water temperature is 1
The temperature of the cooling device was 5 ° C, the surface temperature of the cooling device was 18 ° C, and the surface temperature of the support after cooling was completed was 23 ° C. The thickness of the charge generation layer was 0.15 μm. The above steps were repeated to form 1,000 continuous charge generating layer coated aluminum cylinders. As a result of visually inspecting the 1000 coated aluminum cylinders and separating defective products due to coating defects,
There were 20 defective coated aluminum cylinders.

Example 3 1000 parts of a styryl compound having the following structural formula:

[0044]

Embedded image

1000 parts of a polycarbonate resin was dissolved in 5000 parts of monochlorobenzene and 3000 parts of dichloromethane, and this solution was filtered through a filter having an opening diameter of 5.0 μm to remove residual undissolved substances, dust and the like, and to form a coating solution for a charge transport layer. Was adjusted.

The above-mentioned coating liquid for a charge transport layer was further dip-coated on a non-defective aluminum cylinder (φ120 mm × 360 mm, wall thickness 5 mm) coated with a charge generation layer in Example 2, and dried at 130 ° C. for 40 minutes by a drier. did.

After the drying was completed, it was cooled for 10 minutes by the cooling device shown in FIG. The temperature of the cooling water was 15 ° C., the surface temperature of the cooling device was 18 ° C., and after the cooling was completed, the surface temperature of the support was 23 ° C.

The thickness of the charge transport layer was 25 μm. The above steps were repeated to produce 1,000 continuous charge transport layer coated aluminum cylinders. The 1,000 coated aluminum cylinders were visually inspected to isolate defective products due to coating defects. As a result, 26 defective coated aluminum cylinders were found.

Comparative Example 1 An example of the contact cooling device used in Comparative Example 1 is shown in FIG. The contact cooling device 1 is made of silicone rubber and is controlled by a cooling pipe 4 inside so that the surface temperature becomes constant. The outer diameter of the contact cooling device is the same as the inner diameter of the support (aluminum cylinder) 6 . Furthermore, since the material is silicon rubber and has elasticity, it is in close contact with the support . But
However, the internal pressure of the device as in the contact cooling device shown in FIG.
It is not designed to adjust the
It cannot be shrunk or shrunk. After the coating of the support is completed, the coating liquid adhering to the inner surface of the cylinder is peeled off and removed. Carried over and inserted into a contact cooling device. After the cooling is completed, the sheet is transferred to the next step by the transfer means.

A coating solution for a charge transport layer was prepared in exactly the same manner as in Example 3. The coating material was dip-coated on the same aluminum cylinder coated with the charge generation layer as in Example 3, and dried at 130 ° C. for 40 minutes by a drier.

After the drying was completed, it was cooled for 10 minutes by the cooling device shown in FIG. The temperature of the cooling water was 12 ° C., the surface temperature of the cooling device was 18 ° C., and after the cooling was completed, the surface temperature of the support was 23 ° C.

The thickness of the charge transport layer was 25 μm. The above steps were repeated to produce 1,000 continuous charge transport layer coated aluminum cylinders. The 1,000 coated aluminum cylinders were visually inspected, and defective products due to coating defects were separated. As a result, 30 defective coated aluminum cylinders were found.

Comparative Example 2 FIG. 3 shows a cooling device used in this comparative example. The support 6 after drying includes a cylinder chucking jig 7, an up-down telescopic arm 8,
It is conveyed to the front of the blower cooling device (blower 12) by a transfer means including a transfer unit 9 and a transfer rail 10, cooled, and then transferred to the next step by the transfer means.

A coating solution for a conductive layer and a coating solution for an intermediate layer were prepared in exactly the same manner as in Example 1. The coating material for the conductive layer was dip-coated on the same aluminum cylinder as in Example 1, and dried at 160 ° C. for 20 minutes using a drying device. After the drying was completed, the support was cooled by the blower cooling device shown in FIG. 3 until the surface temperature of the support became 23 ° C. Cooling took 15 minutes. The thickness of the conductive layer was 20 μm.

The intermediate layer paint was dip-coated on the aluminum cylinder coated with the conductive layer, and dried at 95 ° C. for 7 minutes by a drier. After the drying was completed, the substrate was cooled by the blower cooling device shown in FIG. 3 until the surface temperature of the substrate reached 23 ° C. Cooling took 10 minutes. The thickness of the intermediate layer is 0.5
μm.

The above steps were repeated to prepare 1,000 continuous conductive layer and intermediate layer coated aluminum cylinders.
The 1,000 coated aluminum cylinders were visually inspected to separate defective products due to coating defects. As a result, 93 defective coated aluminum cylinders were found.

As a result of observing the defective conductive layer coated aluminum cylinder, hardened dust of the conductive layer coating liquid was observed inside the intermediate layer. Defective products occur frequently in the latter half of the continuous coating, and it can be said that the hardened dust of the conductive layer coating liquid generated in the drying step by the continuous coating adheres to the coating surface during cooling.

COMPARATIVE EXAMPLE 3 A coating solution for a charge generating layer exactly the same as in Example 2 was prepared. The paint for a charge generation layer was further applied by dip coating onto the non-defective intermediate layer coated aluminum cylinder prepared in Comparative Example 2 , and dried at 85 ° C. for 7 minutes by a drier.

After the drying was completed, the support was cooled by the blower cooling device shown in FIG. 3 until the surface temperature of the support became 23 ° C. 1
It took 0 minutes. The thickness of the charge generation layer was 0.15 μm. The above steps were repeated to form 1,000 continuous charge generating layer coated aluminum cylinders. This 100
As a result of visually inspecting the zero coated aluminum cylinders and separating defective products due to coating defects, 43 defective coated aluminum cylinders were found. Observation of the defective charge-generating layer-coated aluminum cylinder revealed dust inside the charge-generating layer.

Comparative Example 4 A coating solution for a charge transport layer was prepared in exactly the same manner as in Example 3. The above-mentioned paint for a charge transport layer was further dip-coated on the aluminum cylinder coated with a good charge generation layer prepared in Comparative Example 3 and dried at 130 ° C. for 40 minutes by a drier.

After the drying was completed, the support was cooled by the blower cooling device shown in FIG. 3 until the surface temperature of the support became 23 ° C. 1
It took two minutes. The thickness of the charge transport layer was 25 μm. The above steps were repeated to produce 1,000 continuous charge transport layer coated aluminum cylinders. This 1000
As a result of visually inspecting the coated aluminum cylinders and separating defective products in which dust was observed inside the charge transport layer, 50 defective aluminum cylinders were found.

Comparative Example 5 A coating solution for a charge transport layer exactly the same as in Example 3 was prepared. The above-mentioned paint for a charge transport layer was further dip-coated on the aluminum cylinder coated with a good charge generation layer prepared in Comparative Example 3 and dried at 130 ° C. for 40 minutes by a drier.

After the drying was completed, the support was cooled by natural cooling until the surface temperature of the support reached 23 ° C. Cooling took 22 minutes. The thickness of the charge transport layer was 25 μm.
The above steps were repeated to produce 1,000 continuous charge transport layer coated aluminum cylinders. The 1,000 coated aluminum cylinders were visually inspected to separate defective products in which dust was observed inside the charge transport layer. As a result, 40 defective aluminum cylinders were found.

[Evaluation of Actual Machine] The electrophotographic photosensitive members prepared in Example 3 , Comparative Examples 1, 4 and 5 were mounted on a copying machine in which charging, exposure, development, transfer and cleaning processes were repeated in a 0.8 second cycle. Was. As a result, in Example 3 and Comparative Example 1, uniform high-quality images without image defects were obtained. In Comparative Examples 4 and 5 , image defects due to dust in the photosensitive layer were observed.

Table 1 shows the results of Examples 1 to 3 and Comparative Examples 1 to 5.
Summarized in Example 1 and Comparative Example 2 , Example 2 and Comparative Example
3. Comparing Example 3 with Comparative Examples 4 and 5 , it can be seen that the defective rate is low in the case of contact cooling, but high in the case of air cooling and natural cooling. In addition, both employ contact cooling
The comparison between the adopted Example 3 and Comparative Example 1 shows that the cooling device
Failure rate of contact cooling with a mechanism to expand the installation
Contact cooling without this mechanism is low
It can be seen that the defect rate is high. Further, from the results of the image evaluation, the contact cooling showed that there were few image defects and a good image was obtained.

[0066]

[Table 1]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

As is clear from the above, the elasticity
Pressurizes and feeds liquid into a cooling device made of material
Then, by expanding the cooling device, the cooling device is supported.
I by the cooling support is brought into contact with the lifting body, little adhesion of dust during cooling, no image defects, it is possible to manufacture the electrophotographic photoreceptor high quality in good yields it can. In addition, the cooling time is shortened and the production efficiency is improved.

[0095]

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an example of a contact cooling device used in a production method of the present invention.

FIG. 2 is a schematic configuration diagram of an example of a contact cooling device used in the manufacturing method of the present invention.

FIG. 3 is a schematic configuration diagram of a conventional blower cooling device.

FIG. 4 is a schematic configuration diagram of an example of a contact heating device used in the production method of the present invention.

FIG. 5 is a schematic configuration diagram of an example of a contact heating device used in the production method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Contact cooling device 2 Cooling water tank 3 Pump 4 Cooler (cooling pipe) 5 Pressure regulating valve 6 Support (aluminum cylinder) 7 Cylinder chucking jig 8 Vertical telescopic arm 9 Transport unit 10 Transport rail 11 Cooling water 12 Blower 21 Contact Heating device 22 Oil heating tank 23 Pump 24 Electric heater 25 Pressure regulating valve 26 Support (aluminum cylinder) 27 Cylinder chucking jig 28 Vertical telescopic arm 29 Transport unit 30 Transport rail 31 Circulating oil

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Kishi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-63-77061 (JP, A) JP-A-62 -8188 (JP, A) JP-A-56-49115 (JP, A) JP-A-60-5147 (JP, A) JP-A-2-13524 (JP, U) JP-A-3-31422 (JP, U) ) Fully open 1988-4091 (JP, U) Fully open 61-21514 (JP, U) Fully open 1986-188722 (JP, U) Fully open 1986-145525 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) G03G 5/00

Claims (1)

(57) [Claims] 1. A plurality of layers including a photosensitive layer on a conductive support
The manufacturing method of the electrophotographic photosensitive member formed by stacking, the
After applying at least one of the plurality of layers with a coating solution and drying by heating , the liquid is applied to a cooling device made of an elastic material.
Pressure to feed and expand the cooling device.
And forming the cooling device by contacting the cooling device with the support to cool the support.