JPH06118663A - Production of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide an electrophotographic sensitive body which is free from coating defects, such as repelling and staining, of a photosensitive layer by suppressing the remaining of the mists of cutting fluid even if a washing stage for the electrophotographic sensitive body is executed by water washing. CONSTITUTION:A conductive base body 1 consisting of aluminum is immersed into at least one of surfactant-contg. water tanks (washing tanks 11) and thereafter, this conductive base body 1 is immersed into at least one tank of water tanks (1st, second and third rinsing tanks 21, 31, 41) and is rinsed in the process for production of the electrophotographic sensitive body constituted by forming the photosensitive layer on the above-mentioned conductive base body 1. Ultrasonic waves of >=90KHz and <=850kHz are impressed to at least one tank (washing tank 11 and first rinsing tank 21) among the surfactant-contg. water tanks and the water tanks (washing tank 11 and first, second and third rinsing tanks 21, 31, 41) at this time.

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 copying machines, printers and the like.

[0002]

2. Description of the Related Art Generally, an electrophotographic photosensitive member is one in which a photosensitive layer is formed on a cylindrical conductive substrate. This cylindrical conductive substrate is shaped by cutting a cylindrical aluminum surface and subjecting it to mirror finishing or impact molding. Mineral oil such as kerosene naphtha is generally used during cutting or impact molding. This is for cooling the heat generated during cutting or impact molding, preventing wear of the lubricating tool, and improving the surface accuracy of the conductive substrate surface after cutting or impact molding. Mist of cutting oil, dust in the air, chips and the like adhere to the surface of the conductive substrate during mirror-finishing or impact molding. Therefore, after the conductive substrate surface is washed to remove them, a charge generating substance such as a condensed polycyclic pigment or an azo pigment,
A charge transport layer composed of a resin binder, an additive such as an antioxidant, etc. is sequentially applied, laminated and dried to form a photosensitive layer.

The charge generating layer and the charge transporting layer are prepared by immersing the conductive substrate in a coating solution containing the above-mentioned substances constituting the charge generating layer and the charge transporting layer by a known method. Formed on the surface. The dip coating method performed here is not particularly limited, and known methods can be used. For example, JP-A-49-130736, JP-A-SHO-5
7-5047 and the method disclosed in JP-A-59-46171.

In the dip coating method, if the surface of the conductive substrate is insufficiently cleaned, oil, dust and the like remain on the surface, which causes coating defects such as cissing and stains during coating. Defects generated on such an electrophotographic photoreceptor are black spots on a copy image of a copying machine using the electrophotographic photoreceptor.
White spots appear as uneven halftone images, which adversely affects image quality.

As the method for cleaning the surface of the conductive substrate, dipping cleaning in which the conductive substrate is usually immersed in a heated organic solvent and / or under the action of ultrasonic waves, conductive substrate is used. Contact cleaning in which the solvent is physically rubbed with a brush, sponge, etc. while being immersed in a solvent or while showering the solvent on the conductive substrate, jet cleaning in which the solvent is jetted from the slit to the surface of the conductive substrate, and the conductive substrate in the solvent vapor Is used, and the surface of the conductive substrate is cleaned singly or in combination.

As the solvent used here, methyl chloride, ethylene chloride, 1.1.1-trichloroethane, trichloroethylene, perchlorethylene,
Chlorine-based solvent such as CFC-112, CFC-112, CFC-113 and other fluorine-based solvent, mixed solvent of the fluorine solvent and methanol, methylene chloride, etc., benzene, toluene, methanol, ethanol, isopropyl alcohol, petroleum hydrocarbons and the like. A mixture of These solvents include those that are flammable and ignitable, those that have a low permissible concentration because they are harmful to the human body, and those that have a poor cleaning ability. The most commonly used solvent is 1 ．
1.1-Trichloroethane.

As the electroconductive substrate of the electrophotographic photoreceptor,
Examples thereof include a cylindrical substrate or a thin film sheet of a metal such as aluminum, copper, brass, nickel, and stainless steel, or a film obtained by vapor deposition of aluminum, a tin alloy, indium oxide or the like on a cylindrical substrate of a polyester film, paper, or a metal film. Aluminum is the most common in terms of low price, ease of processing, strength and weight.

However, although 1.1.1-trichloroethane has advantages such as high cleaning ability and easy handling, it is considered that it is one of the substances causing global warming, ozone layer depletion and the like. With CFCs, the reduction has been decided all over the world, and the development of an alternative cleaning agent for 1.1.1-trichloroethane and an alternative cleaning method has been earnestly desired.

In recent years, as an alternative cleaning method, water cleaning has been studied in which the surface of the conductive substrate is cleaned with city water, pure water, ion-exchanged water, or water containing a nonionic surfactant and / or an anionic surfactant. ing.

This is done by immersing oil and dust adhering to the surface of the conductive substrate in water containing a surfactant, which has been micellarized under the action of ultrasonic waves, and then immersing the surface of the surface by immersing it in a water bath. This is a method of rinsing the adhering surfactant.

[0011]

However, when water is washed by excessively acting ultrasonic waves for the purpose of enhancing the cleaning effect, water has a higher surface tension than organic solvents and the ultrasonic waves act strongly. When aluminum is used as the conductive substrate, pinhole defects are likely to occur in the conductive substrate due to long-term washing with water, and corrosion occurs due to reaction with water, and when a photosensitive layer is formed thereon. There arises a problem that the photosensitive layer becomes a defect such as a stain or coating missing.

On the other hand, if the water cleaning is carried out without applying ultrasonic waves, the cleaning ability is lowered, and not only the cleaning takes a long time but also the cleaning is insufficient, so that stains may be formed on the conductive substrate after cleaning. After the photosensitive layer is applied, the coating is not applied, which easily causes a coating drop.

In view of the above points, the present invention uses a conductive substrate made of aluminum for an electrophotographic photosensitive member, and even when water cleaning is performed as the cleaning method, pinhole defects, stains, and photosensitive layer of the conductive substrate are caused. The present invention provides a method for producing an electrophotographic photosensitive member which does not cause defects such as coating loss.

[0014]

The present invention is a method for producing an electrophotographic photosensitive member in which a photosensitive layer is formed on a conductive substrate made of aluminum, before forming a photosensitive layer on the conductive substrate. The step of immersing the conductive substrate in at least one tank containing a surfactant and the step of immersing the conductive substrate immersed in the tank containing a surfactant in at least one tank An ultrasonic wave having a frequency of 90 KHz or more and 850 KHz or less is applied to at least one of the contained water tank and the water tank.

[0015]

When the conductive substrate is immersed in the water bath containing the surfactant, the lipophilic group of the surfactant acts on the cutting oil adhering to the conductive substrate, so that the cutting oil is removed from the conductive substrate into the water. Is almost eliminated. By immersing the conductive substrate in this state in a water tank, the surfactant, residual cutting oil, etc. adhering to the conductive substrate are rinsed off.

Since the conductive substrate is made of aluminum, it needs to be treated in a short time in order to prevent corrosion by immersion in water. Therefore, ultrasonic waves are applied to the surfactant-containing water tank and the rinsing water tank. Let As a result, the effect of removing cutting oil and the like and the effect of rinsing are improved, and the processing time can be reduced. In order to obtain this effect sufficiently, it is necessary to set the frequency of this ultrasonic wave to 850 KHz or less.

On the other hand, when an excessive ultrasonic wave is applied to the surfactant-containing water tank and the rinsing water tank, a pinhole defect is generated in the conductive substrate, and the reaction with water is promoted to cause corrosion, on which the photosensitive layer is formed. Since a defect such as a stain or coating missing is formed on the photosensitive layer when the above is formed, it is necessary to set the frequency of ultrasonic waves to 90 KHz or more.

The surfactant-containing water tank and the rinsing water tank may be provided in plural in order to enhance the cleaning effect of the conductive substrate. At this time, it is not necessary to apply ultrasonic waves to all tanks, and the above effect can be obtained by applying ultrasonic waves to at least one tank.

In this way, the cutting oil, dust, and chips can be sufficiently removed in a short time, so that the conductive substrate is not corroded or pinhole defects are generated, and when the photosensitive layer is formed thereon. It is possible to suppress the generation of spots and coating loss.

[0020]

【Example】

(Examples) Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

FIG. 1 is a schematic view of a cleaning apparatus used in this embodiment. A conductive substrate 1 which has been conventionally cut or impact-formed by a conventional method is supported by a robot band 2 arranged on a rail 3.

The first cleaning tank 11 is filled with a cleaning solution 18 of pure water in which a surfactant is dissolved, and the cleaning solution 18 is heated by a heater 16 to 40 to 60 ° C., here 50 ° C., and An ultrasonic oscillator 17 is provided at the bottom of the cleaning tank 11.
Is provided so that ultrasonic waves of a predetermined frequency oscillate when the conductive substrate is immersed. In the cleaning tank 11, a cleaning liquid is constantly fed from a tank (not shown) from a pipe 12. The cleaning liquid in which the oil, dust, and chips removed from the surface of the conductive substrate 1 by cleaning is dispersed is the pipe 19
Circulates through the filter 15 by the pump 14 and dust and chips are captured by the filter 15. The liquid that overflows due to the immersion of the conductive substrate 1 is discharged from the pipe 13. The discharged cleaning liquid is processed by a drainage processing device (not shown).

The first rinsing tank 21, the second rinsing tank 31, and the third rinsing tank 41 are respectively rinse water 25, 35, 45.
Is filled with pure water at 25 ° C. An ultrasonic oscillator 24 is provided at the bottom of the rinsing tank 21 so that ultrasonic waves of a predetermined frequency oscillate when the conductive substrate 1 is immersed. The rinsing liquid in each rinsing tank is connected to the pipes 26, 36, 4 respectively.
6 to filter 23, by pumps 22, 32, 42,
It circulates through 33 and 43, and dust and chips are captured by the filter. The rinsing liquid is supplied from the tank 60 to the rinsing tank 41, the third rinsing tank 41 overflows to supply the rinsing liquid to the second rinsing tank 31, and the second rinsing tank 31 overflows to the first rinsing tank. 21
The rinsing liquid is supplied to the first rinsing liquid, and the liquid overflowing from the first rinsing tank 21 is discharged from the pipe 27 and treated by the drainage treatment device.

The pH of the cleaning liquid 18 in the cleaning tank 11 is 6.0 to 6.0.
It is 9.0, preferably 6.5 to 8.0. Since the conductive substrate 1 is aluminum, if the pH of the cleaning liquid is controlled to 6.0 to 9.0, the formation of hydroxides, oxides, and hydrates that corrode the surface of the aluminum substrate is suppressed,
This is because changes in physical properties such as wettability due to the reaction product do not occur, so that it is possible to suppress the occurrence of coating defects such as cissing, spots, and coating loss during coating.

As the surface active agent used in the cleaning liquid 18, a nonionic surface active agent and / or an anionic surface active agent which does not corrode a conductive substrate made of aluminum can be used. Specifically, polyoxyethylene alkyl is used. Nonionic surfactants of phenyl ether, polyoxyethylene, polyoxypropylene, block copolymer type and nonylphenol polyoxyethyl ether, and sulfates, silicates, carbonates or phosphates of alkylbenzenes, higher alcohols, α-olefins and the like. Anionic surfactants of Among them, T-180 manufactured by Henkel Hakusui Co., Ltd. and FM-10 manufactured by Lion Co., Ltd. are used as the surfactant for forming the cleaning liquid having a pH of 6.0 to 9.0.
And Lyomix L, Lyomix-H, CA01 manufactured by Chemix Co., Ltd., and Cleanthrough 750L manufactured by Kao Corporation.

The concentration of the surfactant in the cleaning liquid 18 is 0.
It is 5 to 30%, preferably 4 to 15%. In this embodiment, Poraculin 6 manufactured by Tanaka Import Group Co., Ltd.
90 5% pure water solution was used.

In addition, as a cleaning aid (builder), an inorganic builder such as sodium carbonate, sodium tripolyphosphate, sodium pyrophosphate, sodium silicate, sodium sulfate, etc., and an organic builder such as carboxymethyl cellulose, methyl cellulose, organic amine, etc. are used in the cleaning liquid 18. You may add.

In the cleaning tank 11 and the first rinsing tank 21, the conductive substrate 1 is immersed and cleaned for 0.5 to 10 minutes. Here, the immersion was performed under the conditions of 0.5 minute and 1 minute as described below.

In the second and third rinsing tanks 31 and 41, the conductive substrate 1 is added for 0.5 to 10 minutes, preferably 1.
Soak for 5 to 5 minutes. Here, each was performed for 2 minutes.

The cleaned conductive substrate 1 has a cleanness of 10
In the clean booth 60 kept at 0, 80 ° C. clean air is blown to dry.

In the above-mentioned water washing step, the pinhole defect and the washability were examined by changing the frequency of the ultrasonic waves applied to the conductive substrate 1 in the wash tank 11 and the rinse tank 21. The results are shown in Table 1. Here, the ultrasonic output is 40
The evaluation method is 2 m for pinhole defects.
The number of places where 5 or more pinhole defects having a size of 5 μm or more exist within m ² , and the cleaning property is determined by counting the number of deposits having a size of 1 μm or more.

[0032]

[Table 1]

From Table 1, from the viewpoint of preventing pinhole defects, 9
It is preferably 0 KHz or more and 850 KHz or less from the viewpoint of cleanability.

Of these, cleaning at 200 KHz for 30 seconds is most preferable.

Based on the results of Table 1, the cleaning tank 11 and the first
The condition of ultrasonic wave application in the rinsing tank 21 is 200 KHz, 3
The conductive substrate was washed at 0 second.

A photosensitive layer is formed on the surface of the conductive substrate 1 by a known method. For example, a charge generation layer is formed on the surface of the conductive substrate 1 that has been washed by a dip coating method, a link method coating method, or a spray coating method, and then the dipping coating method or a spray coating method is formed on the charge generating layer. To form a charge transport layer.

The charge generation layer contains a charge generation material which generates charges upon irradiation with light as a main component, and if necessary, known binders, plasticizers and sensitizers, and has a thickness of 1.0 μm or less. Thus, it is coated on the conductive substrate 1. Examples of the charge generation material include perylene pigments, polycyclic quinone pigments, phthalocyanine pigments, metal phthalocyanine pigments, squarylium dyes, azulenium dyes, thiapyrylium dyes, and carbazole skeletons, styrylstilbene skeletons, triphenylamine skeletons, dibenzothiophene. Examples include azo pigments having a skeleton oxadiazole skeleton, a fluoronone skeleton, a bisstilbene skeleton, a distyloxadiazole skeleton, or a distilcarbazole skeleton.

Here, the following solution A was applied by dip coating to a film thickness of 0.5 μm and dried at 75 ° C. for 1 hour to form a charge generation layer.

The charge transport layer contains as an essential component a charge transport material capable of receiving and transporting the charge generated by the charge generating material and a binder, and if necessary, a known leveling agent, a plasticizer and an additive. Contains a sensitizer, etc., and has a dry film thickness of 5 to 70 μm.
It is coated on the charge generation layer so as to be m.

As the charge transporting material, poly-N-vinylcarbazole and its derivative, poly-γ-carbazolylethylglutamate and its derivative, pyrene-formaldehyde condensate and its derivative, polyvinylpyrene, polyvinylphenatolenoxazole derivative, Oxodiazole derivative, imidazole derivative, 9- (p-diethylaminostyryl) anthracene, 1,1-bis (4-
Electron donors such as dibenzylaminophenyl) propane, styrylanthracene, stilpyrazolin, phenylhydrazones, hydrazone derivatives, or fluorenone derivatives, dibenzothiophene derivatives, indenothiophene derivatives, phenanthrenequinone derivatives, indenopyridine derivatives, thioxanthone derivatives Examples thereof include electron-accepting substances such as benzo (c) cinnoline derivative, phenazine oxide derivative, tetracyanoethylene, tetracyanoquinodimethane, promannyl, chloranil, and benzoquinone. The binder constituting the charge transport layer may be one that is compatible with the charge transport material, for example, polycarbonate, polyvinyl butyral, polyamide,
Examples thereof include polyester, polyketone, epoxy resin, polyurethane, polyvinyl ketone, polystyrene, polyacrylamide, phenol resin, and phenoxy resin.

Here, the following liquid B was applied by dip coating to a film thickness of 20 μm and dried at 75 ° C. for 1 hour to form a charge transport layer.

Liquid A: 2 parts by weight of dibromoanthanthrone, 2 parts by weight of butyral resin (S-REC BM-2 manufactured by Sekisui Chemical Co., Ltd.),
A solution obtained by dispersing 230 parts by weight of cyclohexanone in a ball mill for 8 hours.

Liquid B Hydrazone charge transport material (ABP manufactured by Nippon Kayaku Co., Ltd.)
H) 1 part by weight, a solution obtained by dissolving 1 part by weight of a polycarbonate resin (Panlite L-1250 manufactured by Teijin Chemicals Ltd.) in 8 parts by weight of dichloroethane.

An undercoat layer may be provided to improve the adhesiveness of the photosensitive layer, improve the coatability, cover defects in the conductive substrate 1 and improve the charge injection property from the conductive substrate 1 to the charge generating layer. good. As the material of the undercoat layer, polyamide, copolymer nylon, casein, polyvinyl alcohol, cellulose,
Resins such as gelatin are known. These are dissolved in various organic solvents and coated so as to have a film thickness of about 0.1 to 5.0 μm.

Electrophotographic photoreceptor 3 thus formed
No. 0 was mounted on a copying machine (SF-8100 manufactured by Sharp Corporation) to make a copy, and image evaluation was performed. The results are shown in Table 2.
Shown in. Here, the evaluation is 0.5 m for 30 photoconductors.
The number of black and white spots on an image having a size of m or more and the presence or absence of unevenness in a halftone image. (Comparative Example 1) In Example 1, instead of washing with water using the washing apparatus shown in FIG.
-Wave bath cleaning with ultrasonic waves using trichloroethane
After performing a cold bath cleaning treatment using 1.1.1-trichloroethane at 20 ° C. for 0 seconds for 30 seconds, 1.1.1
-Steam cleaning with trichloroethane was carried out for 30 seconds, and the product was allowed to cool in a clean booth with a cleanness of 100 for 20 minutes.

Other than the above, an electrophotographic photosensitive member was prepared in the same manner as in Example 1, and 30 electrophotographic photosensitive members obtained were mounted on a copying machine (SF-8100 manufactured by Sharp Corporation) to make a copy, and an image was obtained. An evaluation was made. The results are shown in Table 2.

(Comparative Example 2) In Example 2, the cleaning tank 1 was used.
The frequency of the ultrasonic waves in the first and first rinsing tanks 21 is set to 200 KH.
The electrophotographic photosensitive member 3 was manufactured by changing the z to 28 KHz and preparing the electrophotographic photosensitive member in the same manner as in Example 2.
0 copy machine (Sharp Corporation SF-8100)
The image was evaluated by mounting it on a plate and making a copy. The results are shown in Table 2.

[0048]

[Table 2]

As is clear from Examples 1 and 2, and Comparative Examples 1 and 2, by setting the frequency of the ultrasonic waves applied to the cleaning tank and the rinsing tank to 90 to 850 KHz, the cleaning performance is improved and the pin of the conductive substrate is improved. Hole defects can be prevented. Therefore, the rate of non-defective products when used as an electrophotographic photosensitive member can be increased.

[0050]

According to the present invention, it is possible to improve the cleaning property and prevent pinhole defects of the conductive substrate in the step of cleaning the electrophotographic photosensitive member. The occurrence of white spots and black spots on the copied image due to coating defects such as cissing and stains is suppressed, and the non-defective rate is improved.

Further, since no organic solvent is used in the washing process, it is possible to eliminate the risk of air pollution, effects on the human body, ignition and explosion due to ignition.

[Brief description of drawings]

FIG. 1 is a schematic view of a cleaning device used in an embodiment of the present invention.

[Explanation of symbols]

 1 Conductive Substrate 11 Cleaning Tank 21 First Rinse Tank 31 Second Rinse Tank 41 Third Rinse Tank

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuyuki Arai 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Inventor Masayuki Sakamoto 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka (72) Inventor Tatsuhiro Morita 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture

Claims (1)

[Claims] 1. A method of manufacturing an electrophotographic photosensitive member comprising a photosensitive substrate formed on a conductive substrate made of aluminum, wherein at least one conductive substrate is provided before the photosensitive layer is formed on the conductive substrate. Of the surfactant-containing water tank, and a step of immersing the conductive substrate immersed in the surfactant-containing water tank in at least one water tank. A method for producing an electrophotographic photosensitive member, characterized in that ultrasonic waves having a frequency of 90 KHz or more and 850 KHz or less are applied to at least one tank.