JP2010145617A - Electrophotographic photoreceptor, method for manufacturing the same and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a photoreceptor with an organic photosensitive layer, which reduces harmful influence on the human body and environment, has simplified steps, and is excellent in repeating characteristic and environmental stability, and to provide an electrophotographic photoreceptor obtained by the method and an image forming apparatus equipped with the same. <P>SOLUTION: The method for manufacturing an electrophotographic photoreceptor with an organic photosensitive layer includes: a washing step of washing a conductive support with water; an intermediate layer formation step of forming an intermediate layer on the washed conductive support using a coating liquid for an intermediate layer composed of an aqueous medium; and a photosensitive layer formation step of forming a photosensitive layer on the formed intermediate layer. The problem is solved by the method. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing an electrophotographic photoreceptor, an electrophotographic photoreceptor obtained thereby, and an image forming apparatus including the same.

  Generally, an electrophotographic photoreceptor (hereinafter also referred to as “photoreceptor”) is produced by forming a photosensitive layer on a conductive support. At this time, if the surface of the conductive support is contaminated with cutting scraps or oil during processing, dust in the air, human fingerprints, etc., a uniform layer cannot be formed, and an uneven layer will be formed. . In addition, the contaminants that cause the contamination itself adversely affect the photosensitive characteristics and cause image defects. Therefore, before forming the photosensitive layer on the conductive support, it is necessary to first thoroughly wash the surface of the conductive support.

  Conventionally, organic solvents such as halogenated hydrocarbons such as trichlorethylene, trichloroethane, dichloromethane, and carbon tetrachloride have been used for cleaning conductive supports from the aspects of degreasing, nonflammability and quick drying. ing. However, these organic solvents are harmful to the human body and have an adverse effect on the environment. In order to prevent these adverse effects, large-scale facilities are required, and there are problems in terms of installation location and cost.

Therefore, a cleaning method using water without using an organic solvent has been proposed.
Since water is inferior in degreasing properties as compared with an organic solvent, water to which a detergent such as a surfactant is added is generally used.
Japanese Patent Laid-Open No. 2007-50401 (Patent Document 1) discloses a technique for cleaning a metal material by applying ultrasonic vibration to negative ion water without using a detergent.
However, in any of the methods, water is much less volatile than an organic solvent. Therefore, it is necessary to sufficiently dry after washing the conductive support and before forming (coating) the photoreceptor layer. .

On the other hand, the photoconductor has a configuration in which an intermediate layer, a charge generation layer and a charge transport layer are stacked in this order on a conductive support, and a layered (functional separation type) photosensitive layer is stacked in this order. Has become the mainstream.
The intermediate layer can improve the adhesion of the photosensitive layer by coating defects on the conductive support, improve the film formability (coatability), prevent unnecessary charge injection from the conductive support, and improve the chargeability associated therewith. These are roughly classified into those composed of a resin alone and those composed of a resin containing a pigment.
Examples of the resin used for the intermediate layer include water-soluble resins such as polyvinyl alcohol and casein, alcohol-soluble resins such as copolymer nylon resins, polyurethane, melamine resins, phenol resins, alkyd resins, epoxy resins, and siloxane resins. Examples thereof include a thermosetting resin that forms a network structure.

However, since water-soluble resins and alcohol-soluble resins are rich in moisture adsorption and affinity, there is a problem that physical properties are extremely dependent on the environment, and the characteristics of the photoreceptor are changed by humidity. In particular, since the intermediate layer absorbs a large amount of moisture at high humidity, repeated use of the photoreceptor at high temperature and high humidity or low temperature and low humidity greatly changes its characteristics and causes abnormal images such as black spots and density reduction.
Therefore, a thermosetting resin that forms a three-dimensional network structure excellent in solvent resistance and environmental stability was adopted.

  However, for example, melamine resins disclosed in Japanese Patent No. 3657138 (Patent Document 2), for example, resins such as phenol resin and methoxymethylated nylon disclosed in Japanese Patent No. 2707341 (Patent Document 3) Formaldehyde, which is said to be one of the causative substances of sick house syndrome at the time of resin production and is currently listed as a target substance in the Air Pollution Control Law, is used in large quantities. Therefore, there is a problem that unreacted substances during production are occluded in the resin, and formaldehyde is generated in the process of thermal crosslinking after the formation of the intermediate layer of the photoreceptor. In order to prevent the release of the generated formaldehyde into the atmosphere, a recovery facility is necessary, and it is obviously expensive to introduce the facility.

In addition, for example, in the urethane resin disclosed in Japanese Patent No. 2790380 (Patent Document 4), an active hydrogen-containing group such as a polyol compound and an isocyanate group of an isocyanate compound that is a curing agent have a three-dimensional network crosslinking reaction. No formaldehyde is generated since a cured film is formed. However, since the reactivity of the isocyanate group is very high, there is a problem that the pot life of the coating liquid using these is very short.
Therefore, a method using a blocked isocyanate compound in which an isocyanate group is protected with a blocking agent such as oxime has been reported, and the pot life of a coating liquid using an organic solvent has been considerably improved (for example, JP-A-2005-115351). Publication (refer patent document 5)).
Organic solvents such as methanol, propanol, dioxolane and the like are used as solvents for using these resins as coating solutions.

JP 2007-50401 A Japanese Patent No. 3657138 Japanese Patent No. 2707341 Japanese Patent No. 2790380 JP 2005-115351 A

  The present invention relates to a method for producing a photoreceptor having an organic photosensitive layer, which has reduced adverse effects on the human body and the environment, has simplified processes, and has excellent repetitive characteristics and environmental stability, and an electrophotographic photosensitive film obtained thereby. It is an object to provide a body and an image forming apparatus including the body.

  As a result of intensive studies to solve the above problems, the present inventors have conducted a washing step of washing the conductive support with water, and an intermediate layer using an intermediate layer coating solution comprising an aqueous medium. The present inventors have found that the above problems can be solved by combining the intermediate layer forming step to be formed, and have completed the present invention.

According to the present invention, a washing step of washing the conductive support with water;
An intermediate layer forming step of forming an intermediate layer on the washed conductive support using an intermediate layer coating solution made of an aqueous medium;
And a photosensitive layer forming step of forming a photosensitive layer on the formed intermediate layer. A method for producing a photoreceptor having an organic photosensitive layer is provided.

In addition, according to the present invention, there is provided a photoreceptor obtained by the above production method.
Further, according to the present invention, the above-described photoconductor, a charging unit for charging the photoconductor, an exposure unit for exposing the charged photoconductor to form an electrostatic latent image, and the exposure unit are formed by exposure. Developing means for developing the electrostatic latent image to form a toner image, transfer means for transferring the toner image formed by development onto a recording material, and fixing the transferred toner image on the recording material The image forming apparatus includes at least a fixing unit that forms an image, a cleaning unit that removes and collects toner remaining on the photoconductor, and a neutralizing unit that neutralizes surface charge remaining on the photoconductor. An apparatus is provided.

According to the present invention, a method for producing a photoreceptor having an organic photosensitive layer with reduced adverse effects on the human body and the environment, simplified processes, excellent repetitive characteristics and environmental stability, and the electron obtained thereby A photographic photoreceptor and an image forming apparatus including the same can be provided.
That is, adverse effects on the human body and the environment are reduced by washing the conductive support with water and using the intermediate layer coating solution made of an aqueous medium.
Further, the drying time of the conductive support after washing of the conductive support and before the formation of the intermediate layer can be shortened, and the process can be simplified and the energy can be reduced.
Furthermore, since residual impurities and uneven drying after cleaning of the conductive support are reduced, it is possible to provide an image forming apparatus in which image defects are unlikely to occur.

  Furthermore, when an aqueous medium is used as a solvent for the intermediate layer coating solution, a resin having a high affinity for water must be used, and an intermediate layer formed using such an intermediate layer coating solution The photoconductor having the is inferior in moisture resistance. However, in the present invention, the resin is thermally cured with an isocyanate compound, the hydrophilic functional groups in the resin are reduced, and the coating film is densified as a cured film, so that the moisture resistance of the photoreceptor is improved and excellent. Environmental stability can be obtained.

The isocyanate group of the isocyanate compound reacts easily with water. However, in the present invention, since a blocked isocyanate compound in which an isocyanate group is protected with a stable protective group in water is used, a pot life equivalent to or higher than that of a conventional organic solvent-based coating liquid can be realized.
Further, by using a resin having two or more active hydrogen-containing groups capable of reacting with an isocyanate group such as a hydroxyl group or an amide group, it can be easily thermoset with an isocyanate compound.
Furthermore, in the present invention, a dense cured film is formed by the presence of the isocyanate group in the blocked isocyanate compound at a molar ratio of 0.5 to 1.5 with respect to the active hydrogen-containing group in the resin. And excellent environmental characteristics as a photoreceptor.

  By adding acicular titanium oxide fine particles to the intermediate layer coating liquid, a coating liquid excellent in dispersibility and storage stability can be obtained, and the intermediate layer can be produced without coating unevenness. Therefore, even if it is used repeatedly, a photoconductor with little residual potential accumulation and little photosensitivity deterioration can be produced.

The method for producing a photoreceptor having an organic photosensitive layer according to the present invention comprises a washing step of washing a conductive support with water, and an intermediate layer coating solution comprising an aqueous medium on the washed conductive support. And an intermediate layer forming step for forming an intermediate layer, and a photosensitive layer forming step for forming a photosensitive layer on the formed intermediate layer.
Each step will be described below.

(Washing process)
Wash the conductive support with water.
In the washing step, the conductive support is immersed in water and ultrasonic waves are applied, and then the conductive support is removed from water at a speed of 2 to 10 mm / s, preferably 3 to 10 mm / s, more preferably 5 to 7 mm / s. Preferably it consists of pulling up with s.
Instead of a method of applying ultrasonic waves, a method of moving a brush or a blade while being pressed against a conductive support, or a method of jetting high-pressure water using a jet nozzle or the like may be used.
Further, instead of lifting the conductive support from the water, the conductive support may be treated with a pure water shower.
Ultrasonic conditions may be appropriately adjusted depending on the size of the conductive support, the volume of water, and the like. For example, the frequency is 10 to 60 kHz, the output is 0.5 to 2 kW, and the time is 1 to 3 minutes.

The “water” in the cleaning process of the present invention generally means water used for cleaning materials, devices, instruments and the like in the technical field.
The water is preferably pure water having a conductivity of 1 μS / cm or less, preferably 0.8 to 1.0 μS / cm.
Further, the water preferably has a temperature of 25 to 50 ° C, preferably 40 to 50 ° C.
By using pure water or warm water, preferably pure warm water, a higher cleaning effect can be obtained.

(Preliminary washing process)
The method for producing a photoreceptor of the present invention preferably further includes a preliminary cleaning step of cleaning the conductive support with water containing a surfactant before the cleaning step.
Moreover, in order to improve the washing | cleaning effect, water may contain the well-known adjuvant of weak acids-weak alkalis other than surfactant.
The surfactant is a compound composed of a hydrophobic group and a hydrophilic group, has a property of easily gathering at the interface between two substances (support and oil as an impurity), and is effective in detachment between the two substances.
Examples of such surfactants include known compounds, for example, ionic compounds such as aliphatic higher alcohol sulfate sodium salt, alkyltrimethylammonium chloride and alkyldimethylbetaine, and aliphatic higher alcohol ethylene oxide addition. Nonionic compounds such as products (polyethylene glycol alkyl ether).

What is necessary is just to set suitably the content rate of surfactant according to the grade of the contamination of an electroconductive support body, for example, is about 0.1-20 weight part with respect to 100 weight part of water.
By using water (cleaning medium) containing a surfactant, a higher cleaning effect can be obtained.

(Draining process)
The method for producing a photoreceptor of the present invention preferably further includes a draining step for removing water adhering to the conductive support between the washing step and the intermediate layer forming step.
Subsequent drying can be shortened by the draining step, or the drying step itself can be eliminated. The draining step is (1) rotating the conductive support and splashing water by the centrifugal force, or (2) resin. It is preferable to remove water adhering to the conductive support by moving the blade made in pressure contact with the conductive support.
These methods can efficiently and reliably drain water with a small and simple device.

Drawing 1 is a mimetic diagram showing the draining device used for method (1).
In addition, the following is description of a main member, and the peripheral member should just be set suitably so that an impurity may not adhere again to an electroconductive support body.
This apparatus comprises holders 51 and 52 that support the upper and lower end surfaces of the cylindrical conductive support 1 and a rotating means (motor) M. The lower holder 52 is rotatable about the cylindrical axis of the cylindrical conductive support 1, and the upper holder 51 is engaged with the rotating means M, and the rotation of the holder 51 causes an arrow about the cylindrical axis. The cylindrical conductive support 1 rotates in the direction of.
What is necessary is just to set the rotation speed of the rotation means M at the time of draining suitably by the magnitude | size of a cylindrical conductive support, etc., for example, it is about 200-1000 rpm.

2 and 3 are a schematic exploded view and a schematic view showing a draining device used in the method (2).
In addition, the following is description of a main member, and the peripheral member should just be set suitably so that an impurity may not adhere again to an electroconductive support body.
This device comprises a disc-shaped draining member 40 having holes drilled in concentric circles and disc-shaped blocks 41 and 42 having holes drilled in concentric circles, which are sandwiched from above and below, as shown in FIG. In this way, the cylindrical conductive support 1 passes through the draining member 40.

The draining member has a hardness A of 20 to 90 degrees (JIS K6253 durometer type A), and can remove water adhering to the conductive support by moving it while being pressed against the cylindrical conductive support. The material is not particularly limited as long as it can be used, and examples thereof include a resin blade such as polyurethane.
In the case of a cylindrical conductive support, the diameter of the hole of the draining member is smaller than the diameter, for example, the diameter of the hole is about 29 mm with respect to the diameter of 30 mm of the cylindrical conductive support.
Further, the blocks 41 and 42 have a function of supporting the draining member, and the diameter of the hole is larger than the diameter of the hole of the draining member, for example, the block 41 and 42 with respect to the diameter of the hole of the draining member of 29 mm. The diameter of the hole is about 40 mm.
In the apparatus, the draining member 40 supported by the blocks 41 and 42 is fixed, and the cylindrical conductive support 1 is driven in the direction of the arrow. The cylindrical conductive support 1 is fixed, and the blocks 41 and 42 are fixed. Any structure in which the supported draining member 40 is driven in the direction of the arrow may be used.

(Drying process)
The method for producing a photoreceptor of the present invention is between the washing step and the intermediate layer forming step, and when subjected to a draining step, the conductive support is then heated to a temperature of 95 to 130 ° C., preferably 100 to 120. It is preferable to further include a drying step of drying with warm air of ° C.

The method for producing a photoconductor of the present invention is performed before the intermediate layer forming step.
A pre-cleaning step of cleaning the conductive support with water containing a surfactant;
A washing step of immersing the conductive support in pure warm water having a conductivity of 1 μS / cm or less, applying ultrasonic waves, and then lifting the conductive support from the water;
It preferably comprises a plurality of steps including a draining step for removing water adhering to the conductive support, and a drying step for drying the conductive support with hot air (Example 1, Example 9-1 and Example). 10-1).

  Water is inferior in volatility compared to organic solvents and takes time to dry itself. Further, the unevenness of moisture adhering to the surface of the conductive support becomes the unevenness of drying and the unevenness of coating of the intermediate layer. As a result, an image defect occurs. In the above-described method, unevenness in adhesion of moisture is eliminated, drying unevenness is prevented, and the amount of adhered moisture can be reduced by the draining process, so that the drying time can be shortened.

Next, the intermediate layer forming step and the photosensitive layer forming step will be described.
An intermediate layer is formed on the washed conductive support using an intermediate layer coating solution made of an aqueous medium.
The intermediate layer forming step of the present invention comprises forming an intermediate layer by applying a thermosetting treatment after applying the intermediate layer coating liquid on the conductive support, and the intermediate layer coating liquid is: It is preferable to include a blocked isocyanate compound, a resin having two or more active hydrogen-containing groups capable of reacting with an isocyanate group in the blocked isocyanate compound, and an aqueous medium.
The use of such an intermediate layer coating solution not only eliminates the problem of air pollution due to VOC in the manufacturing process, but also eliminates the problem of CO ₂ emissions as in the case of conventional petroleum-based solvents. Since it contributes to prevention of global warming and there is no risk of fire, the manufacturing system can be simplified and the manufacturing cost can be reduced.

  A blocked isocyanate compound is a compound in which an isocyanate group of an aqueous isocyanate compound that can be dissolved or dispersed in water is protected with a blocking agent such as oxime, and contains active hydrogen that can react with an isocyanate group such as a hydroxyl group or an amide group by heating. An addition reaction is initiated with the resin having a group, the blocking agent is removed, and the crosslinking reaction proceeds. That is, the blocked isocyanate compound becomes a resin crosslinking agent.

  The aqueous isocyanate compound is a form in which an organic polyisocyanate having a plurality of isocyanate groups in one molecule is modified with various hydrophilic groups such as polyethylene oxide, a carboxyl group or a sulfonic acid group, or dissolved or made into a self-emulsifying type, or It is a compound in a form that is forcibly emulsified with a surfactant or the like so as to be dispersible in water.

Examples of the organic polyisocyanate include phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, naphthylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, hydrogenated diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, hydrogenated toluene diisocyanate. Tetramethylene xylylene diisocyanate; and biuret, uretdione, carbodiimide, isocyanurate, and uretonimine modifications of the isocyanate. These organic polyisocyanates can be used alone or in combination of two or more.
Among these organic polyisocyanates, aliphatic diisocyanate-based organic polyisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate tend to have an affinity for water, so that they can be easily dissolved and dispersed in water and have a crosslinking density. It is particularly preferable because it is easy to increase the value.

In addition, various prepolymers derived from organic polyisocyanates, and further as blocking agents for blocking isocyanate groups in these organic polyisocyanates include active methylene compounds such as ethyl acetate and acetylacetone; butyl mercaptan , Mercaptan compounds such as dodecyl mercaptan, acid amide compounds such as acetanilide and acetic acid amide; lactam compounds such as ε-caprolactam, δ-valerolactam and γ-butyrolactam; acid imides such as succinimide and maleic acid imide Compounds: Imidazole compounds such as imidazole and 2-methylimidazole; Urea compounds such as urea, thiourea and ethyleneurea; Formamide oxime, acetoaldoxime, acetone oxime, methyl ethyl keto Oxime compounds such as shim, methyl isobutyl ketoxime, cyclohexanone oxime; amine compounds such as diphenylaniline, aniline, carbazole, ethyleneimine, polyethyleneimine, etc. These blocking agents may be used alone or in combination of two or more. Can be used in combination.
Among these blocking agents, oxime compounds such as methyl ethyl ketoxime and lactam compounds such as ε-caprolactam are particularly preferable from the viewpoint of versatility, ease of production, and workability.

Further, since the isocyanate group easily reacts with water, it is preferable to use a blocking agent having a dissociation temperature of 110 ° C. or higher so that the blocking agent dissociates after the water in the coating film volatilizes.
Therefore, the blocked isocyanate compound preferably has a structure in which xamethylene diisocyanate or isophorone diisocyanate is blocked with an oxime or lactam blocking agent.

As the blocked isocyanate compound, for example,
Manufactured by Sumika Bayer Urethane Co., Ltd., product names: Bihijoule BL5140, BL5235 and VPLS2310;
Product name: Takenate WB-700WB-820 and WB-920, manufactured by Mitsui Chemicals Polyurethane Co., Ltd .;
Nippon Polyurethane Industry Co., Ltd., developed product name: BWD-102
Asahi Kasei Chemicals Corporation, developed product name: X1238, X1248 and X1258
Etc.

The active hydrogen-containing group in the resin having two or more active hydrogen-containing groups capable of reacting with the isocyanate group in the blocked isocyanate compound is preferably a hydroxyl group or an amide group capable of reacting with the isocyanate group in a high yield.
That is, it has two or more hydroxyl groups or amide groups to form a crosslinked structure with the blocked isocyanate as a curing agent (if it has only one functional group, it does not have a crosslinked structure but has a high molecular weight). Polyol resins and polyamide resins are preferred. Moreover, by controlling the structure of these polyol resins and polyamide resins, they can be dispersed and dissolved in water well, and these resins have high adhesion to the substrate. Image defects due to poor contact with the substrate when used as a photoreceptor can also be effectively prevented.

As these polyol resin and polyamide resin, for example,
Product name: AQD-457 and AQD-473, Asahi Glass Co., Ltd., product name: Exenol 420 and 720, Sanyo Chemical Industries, Ltd., product name: Sannix GP-400, GP-700 And polyether polyol resins such as SP-750;
Hitachi Chemical Co., Ltd., product name: Phthalkid W2343, DIC Corporation, product name: Watersol S-118, CD-520 and BCD-3040, Harima Kasei Co., Ltd., product name: Hallidip WH-1188, etc. Polyester polyol resins of
Product name: Burnock WE-300, WE-304 and WE-306, manufactured by Asia Industry Co., Ltd., product name: WAP-473-FD and WAP-548, manufactured by DIC Corporation;

Manufactured by Kuraray Co., Ltd., product name: polyvinyl alcohol resins such as modified polyvinyl alcohols such as Kuraray Poval PVA-203 and PVA-205;
Manufactured by Sekisui Chemical Co., Ltd., product name: polyvinyl acetal resins such as ESREC K KW-1 and KW-3;
Manufactured by Shin-Etsu Chemical Co., Ltd., product name: cellulose such as water-soluble cellulose ethers such as Metroles 65SH-50 and 65SH-400;
Made by Nagase ChemteX Corporation, product name: Water-soluble nylon (polyamide compound resin) such as Toresin FS-350 and FS-500
Etc.

The isocyanate group of the blocked isocyanate compound is preferably present in the blocked isocyanate compound in a molar ratio of 0.5 to 1.5 with respect to the active hydrogen-containing group of the resin, more preferably 0.5 to 1.2. Preferably, it is 0.6 or more and 1.1 or less.
When the molar ratio (H / B) is less than 0.5 or exceeds 1.5, a large number of unreacted functional groups remain, the crosslinking density is lowered, and the photosensitive layer having the formed intermediate layer is formed. The environmental stability of the body may be reduced.

The intermediate layer coating solution of the present invention may further contain inorganic oxide fine particles.
The inorganic oxide fine particles adjust the volume resistance value of the intermediate layer when it is used as a photoconductor to prevent the injection of carriers from the conductive support to the photoconductive layer, and to improve the electric characteristics of the photoconductor in various environments. It has a function to maintain.

  Examples of the inorganic oxide fine particles include fine particles such as titanium oxide, aluminum oxide, tin oxide, zinc oxide, antimony oxide, silicon oxide, indium oxide, zirconium oxide, magnesium oxide, and barium sulfate. Among these, fine particles of titanium oxide, zinc oxide and aluminum oxide are preferable from the viewpoint of conductivity and dispersibility, and fine particles of titanium oxide and zinc oxide are particularly preferable.

The shape of the inorganic oxide fine particles may be any of dendritic, acicular and granular.
The average primary particle size of the inorganic oxide fine particles is preferably about 20 to 500 nm.

As inorganic oxide fine particles, for example,
Ishihara Sangyo Co., Ltd., product name: TTO-55D (shape: granular, average primary particle size: 30-50 nm), TTO-D-1 (shape: dendritic, average primary particle size: minor axis 40-70 nm, long (Axis: 200 to 300 nm), ST-21 (shape: granular, average primary particle size (measured by X-ray): 70 nm), PT-401M (shape: granular, average primary particle size: 70 nm) and CR-EL (shape: Granular, average primary particle size: 250 nm),
Product name: GTR100 (shape: granular, average primary particle size: 260 nm), manufactured by Sakai Chemical Industry Co., Ltd.
Product name: MT-500SAS (shape: granular, average primary particle size: 35 nm) and JR-603 (shape: granular, average primary particle size: 280 nm)
Fine particles of titanium oxide such as

Ishihara Sangyo Co., Ltd., product name: FZO-50 (shape: granular, average primary particle size: 21 nm),
Product name: FINEX30 (shape: granular, average primary particle size: 35 nm), manufactured by Sakai Chemical Industry Co., Ltd.
Product name: MZ-300 (shape: granular, average primary particle size: 30-40 nm)
Product name: F-2 (shape: rod-shaped, average primary particle size: 65 nm), manufactured by Hakusui Tech Co., Ltd.
And zinc oxide fine particles.

The inorganic oxide fine particles (P) are preferably in a weight ratio (P / R) in the range of 1/1 to 9/1 with respect to the crosslinked resin (total of blocked isocyanate compound and resin: R).
When this weight ratio (P / R) is less than 1/1, the characteristics of the intermediate layer depend on the characteristics of the crosslinked resin, and there is a possibility that the characteristics of the photoconductor may change greatly when the temperature and humidity are changed and used repeatedly. On the other hand, when the weight ratio (P / R) exceeds 9/1, the dispersibility of the inorganic oxide fine particles is lowered, and the possibility of forming an aggregate is increased, and the adhesiveness to the conductive support is lowered. As a result, image defects such as black spots may occur.

The intermediate layer coating solution of the present invention may further contain an antifoaming agent.
The antifoaming agent is intended to suppress foam by adding a very small amount to the intermediate layer coating solution.
When water is used as a solvent as in the intermediate layer coating solution of the present invention, and particularly when a water-soluble resin is added, it is foamed by dispersion or stirring during preparation, and only the dispersion and stirring efficiency is lowered. Instead, it may foam during application and cause coating film defects. Antifoaming agents suppress these problems.

Examples of the antifoaming agent include a silicone system, a surfactant system, a polyether system, a higher alcohol system, an emulsion system, and an oil compound system. Among these, an oil compound system containing silica powder having a strong foam breaking property is particularly preferable.
Examples of antifoaming agents are San Nopco Corporation, product names: SN deformers 444, 470, 485, PC (polyether type), SN deformers 1311, 1316 (silicone type), SN deformers 777, 328, 480, H. -2 (oil compound system), manufactured by Nissho Sangyo Co., Ltd., product name: TSA750 (oil compound system), TSA770 (emulsion system), manufactured by Toray Dow Corning Co., Ltd .: product name: silicone such as DK Q1-1247 -Emulsions are listed.

The antifoaming agent is preferably 0.05 to 0.0005 parts by weight with respect to 1 part by weight of the crosslinked resin (total of blocked isocyanate compound and resin: R).
If the defoamer exceeds 0.05 parts by weight, the electrical characteristics of the photoreceptor may be deteriorated, and if it is less than 0.0005 parts by weight, an effective foam breaking effect may not be obtained.

  The intermediate layer coating solution of the present invention may contain additives such as a viscoelasticity adjusting agent, preservative, and curing catalyst as long as the effects of the present invention are not impaired.

  As the viscoelasticity modifier, for example, manufactured by San Nopco Corporation, product names: SN thickener 601, A816 (polyether type), SN thickener 607 (urethane modified polyether type), SN thickener 617 (modified polyacrylic acid type), A product name: Water-soluble cellulose ether such as Metroze 65SH-4000 manufactured by Shin-Etsu Chemical Co., Ltd. can be mentioned.

  As an antiseptic | preservative, the organic nitrogen sulfur type compound like the product made from San Nopco Co., Ltd. product name: Nopcoside SN-135W etc. are mentioned, for example.

  Examples of the curing catalyst include amine compounds such as triethylamine, diethylethanolamine, and hexamethylenediamine; and organotin compounds such as dibutyltin dilaurate and dioctyltin dilaurate.

In addition, the intermediate layer coating solution of the present invention may contain an electron transporting material in order to adjust conductivity.
Examples of electron transport materials include perylene dyes, quinones such as diphenoquinone and naphthoquinone derivatives, cyano compounds such as tetracyanoethylene and terephthalmalondinitrile, aldehydes such as 4-nitrobenzaldehyde, anthraquinone and alizarin. Anthraquinones are mentioned.

The intermediate layer coating solution of the present invention can be prepared by dissolving or dispersing a blocked isocyanate compound, a resin having two or more active hydrogen-containing groups capable of reacting with an isocyanate group, and an optional additive in an aqueous medium. it can.
The aqueous medium means water or a mixed medium of water and a hydrophilic organic solvent such as a lower alcohol. In the present invention, only water is preferable.

  In order to disperse the components of the intermediate layer coating liquid, especially inorganic oxide fine particles, in water, common dispersers such as paint shakers, ball mills, sand mills, ball mills, sand mills, attritors, vibration mills, ultrasonic dispersers A general grinder such as may be used.

In order to stabilize this dispersion, a dispersion stabilizer may be added to the intermediate layer coating solution.
Examples of the dispersion stabilizer include Sanyo Kasei Co., Ltd., product names: Caribon L-400, Elestat AP-130, Sunspear PS-8, PDN-173, Ionette S-85, New Pole PE-61, and San Nopco shares. Product name: Roma PWA-40, Nobco Santo RFA, SN Dispersant 2060, 5020, 5029, 5468, 7347C and SN Wet P, manufactured by Nissin Chemical Industry Co., Ltd., product names: Surfinol 104E and Olphin PD-003 Product name: Poise 520, 530, Homogenol L 100, Daiichi Kogyo Seiyaku Co., Ltd., Charoru AN-103P, AH-144P, Discoat N-14, Toho Chemical Industries Co., Ltd., product name : Dibrozine A-100, Neoscope 30 And so on.

(Photoreceptor forming process)
In the method for producing a photoreceptor of the present invention, a photosensitive layer is formed on the formed intermediate layer.
The formation process of the photosensitive layer will be described later together with the structure of other photoreceptors.

The photoreceptor of the present invention is obtained by the method for producing a photoreceptor of the present invention.
Next, the photoreceptor of the present invention will be specifically described with reference to the drawings.
4 to 6 are schematic cross-sectional views showing the configuration of the main part of the photoreceptor of the present invention.
FIG. 4 shows the configuration of the main part of a multilayer photoreceptor in which the photosensitive layer is a multilayer photosensitive layer in which a charge generation layer and a charge transport layer are laminated in this order (also referred to as “function separation type photosensitive layer”). It is a schematic cross section.
FIG. 5 is a schematic cross-sectional view showing the configuration of the main part of a multilayer photoreceptor, which is a reverse two-layer multilayer photosensitive layer in which a photosensitive layer is composed of a charge transport layer and a charge generation layer.
FIG. 6 is a schematic cross-sectional view showing the configuration of the main part of a single-layer type photoreceptor that is a single-layer type photosensitive layer having a single photosensitive layer.
The laminated photosensitive layer in FIGS. 4 and 5 may be any, but the laminated photosensitive layer in FIG. 4 is preferred.

4, the intermediate layer 2, the charge generation layer 3 containing a charge generation material, and the charge transport layer 4 containing a charge transport material are laminated on the surface of the conductive support 1 in this order. The laminated photosensitive layer 5 is formed in this order.
In the photoconductor of FIG. 5, an intermediate layer 2, a charge transport layer 4 containing a charge transport material, and a charge generation layer 3 containing a charge generation material are laminated in this order on the surface of the conductive support 1. The reverse two-layer type laminated photosensitive layer 5 is formed in this order.
In the photoreceptor of FIG. 6, an intermediate layer 2 and a single-layer type photosensitive layer 5 ′ containing a charge generation material and a charge transport material are formed in this order on the surface of the conductive support 1.

[Conductive support 1]
The conductive support serves as an electrode for the photoreceptor and also functions as a support member for other layers.
The constituent material of the conductive support is not particularly limited as long as it is a material used in this field.
Specifically, metals and alloy materials such as aluminum, aluminum alloy, copper, brass, zinc, nickel, stainless steel, chromium, molybdenum, vanadium, indium, titanium, gold, platinum: polyethylene terephthalate, polyamide, polyester, polyoxy Polymer material such as methylene, polystyrene, cellulose, polylactic acid, hard paper, glass substrate laminated with metal foil, metal material or alloy material deposited, conductive polymer, tin oxide, oxidation Examples thereof include those obtained by depositing or applying a layer of a conductive compound such as indium or carbon black.

Examples of the shape of the conductive support include a sheet shape, a cylindrical shape, a columnar shape, and an endless belt (seamless belt) shape.
If necessary, the surface of the conductive support is subjected to irregular reflection treatment such as anodizing film treatment, surface treatment with chemicals, hot water, coloring treatment, and surface roughening within a range that does not affect the image quality. May be given.

  The irregular reflection treatment is particularly effective when the photoreceptor according to the present invention is used in an electrophotographic process using a laser as an exposure light source. That is, in the electrophotographic process using a laser as an exposure light source, the wavelength of the laser beam is uniform, so the laser beam reflected on the surface of the photoconductor and the laser beam reflected inside the photoconductor cause interference, Interference fringes due to this interference may appear in the image and cause image defects. Therefore, by performing irregular reflection processing on the surface of the conductive support, it is possible to prevent image defects due to interference of laser light having a uniform wavelength.

[Intermediate layer (also called “undercoat layer”) 2]
The intermediate layer has a function of preventing charge injection from the conductive support to the single-layer type photosensitive layer or the laminated type photosensitive layer. That is, the decrease in chargeability of the single-layer type photosensitive layer or the multilayer type photosensitive layer is suppressed, the decrease in surface charge other than the portion to be erased by exposure is suppressed, and the occurrence of image defects such as fog is prevented. In particular, during image formation by the reversal development process, it is possible to prevent the occurrence of image fogging called black spots in which minute black dots made of toner are formed on a white background portion.

  In addition, the intermediate layer covering the surface of the conductive support reduces the degree of unevenness, which is a defect on the surface of the conductive support, makes the surface uniform, and forms a single layer type photosensitive layer or a multilayer type photosensitive layer. And the adhesion (adhesiveness) between the conductive support and the single-layer type photosensitive layer or the multilayer type photosensitive layer can be improved.

An intermediate | middle layer is obtained by apply | coating the above-mentioned intermediate | middle layer coating liquid to the intermediate | middle layer surface formed on the electroconductive support body, and hardening the obtained coating film, for example.
In the case of a sheet, the application method of the intermediate layer coating solution is the Baker applicator method, the bar coater method (for example, the wire bar coater method), the casting method, the spin coating method, the roll method, the blade method, the bead method, and the curtain method. In the case of a drum, a spray method, a vertical ring method, a dip coating method, etc. are mentioned.
As the coating method, an optimum method may be selected in consideration of the physical properties and productivity of the coating liquid, and the dip coating method, the blade coater method, and the spray method are particularly preferable.

  The dip coating method is a method of forming a layer on the conductive support 1 by immersing the conductive support 1 in a coating tank filled with a coating solution and then pulling it up at a constant speed or a speed that changes sequentially. is there. Since this method is relatively simple and excellent in terms of productivity and cost, it is widely used for manufacturing a photoreceptor. In addition, in order to stabilize the dispersibility of a coating liquid, you may provide the coating liquid dispersion | distribution apparatus represented by the ultrasonic generator in the apparatus used for a dip coating method.

When the coating agent of the blocked isocyanate compound is removed, the resin having two or more active hydrogen-containing groups that can react with the isocyanate group in the blocked isocyanate compound starts an addition reaction with the isocyanate compound, and the coating is cured. Thermal curing is preferable.
The heat curing can be performed using a known apparatus such as a hot air drying furnace and a far-infrared drying furnace, and the conditions may be appropriately set depending on the type of block isocyanate compound or resin used, the mixing ratio, etc. The temperature is 110 to 150 ° C, preferably 130 to 150 ° C, and the time is about 10 minutes to 1 hour.

  Although the film thickness of an intermediate | middle layer is not specifically limited, 0.1-20 micrometers is preferable and 0.5-10 micrometers is especially preferable. If the film thickness of the intermediate layer is less than 0.1 μm, it does not substantially function as an intermediate layer, and a uniform surface property cannot be obtained by covering defects of the conductive support, and carriers are injected from the conductive support. May not be prevented, and the chargeability may decrease. On the other hand, when the film thickness of the intermediate layer exceeds 20 μm, it is difficult to form a uniform coating film, and the sensitivity of the photoreceptor may be lowered.

The intermediate layer in the photoreceptor of the present invention may be not only a single layer but also a plurality of layers.
For example, a first intermediate layer (conductive layer) having a thickness of 2 to 20 μm containing conductive inorganic oxide fine particles and a second intermediate layer (insulating layer) having a thickness of 0.2 to 1 μm not containing inorganic oxide fine particles. A first intermediate layer (insulating layer or blocking layer) having a film thickness of 0.2 to 1 μm containing no inorganic oxide fine particles and a second film having a thickness of 3 to 10 μm containing conductive inorganic oxide fine particles. The combination with an intermediate | middle layer (moire prevention layer) etc. are mentioned.

[Laminated Photosensitive Layer 5]
The laminated photosensitive layer 5 includes a charge generation layer 3 and a charge transport layer 4. As described above, by assigning the charge generation function and the charge transport function to separate layers, the optimum material constituting each layer can be independently selected.
In the following description, a stacked photosensitive layer (FIG. 4) in which a charge generation layer and a charge transport layer are stacked in this order will be described. In the case of an inverted two-layer stacked photosensitive layer (FIG. 5), It is basically the same except that the stacking order is different.

[Charge generation layer 3]
The charge generation layer is mainly composed of a charge generation material having a charge generation capability of generating charges by absorbing irradiated light, and optionally contains a known additive and a binder resin (binder).

As the charge generation material, a compound used in this field can be used.
Specifically, an azo pigment (having a carbazole skeleton, a styryl stilbene skeleton, a triphenylamine skeleton, a dibenzothiophene skeleton, an oxadiazole skeleton, a fluorenone skeleton, a bis-stilbene skeleton, a distyryl oxadiazole skeleton, or a distyryl carbazole skeleton. , Monoazo pigments, bisazo pigments, trisazo pigments, etc.), perylene pigments (peryleneimide, perylene acid anhydride, etc.), polycyclic quinone pigments (quinacridone, anthraquinone, pyrenequinone, etc.), phthalocyanine pigments (metal phthalocyanine, no Metal phthalocyanine, halogenated metal-free phthalocyanine, etc.), indigo pigments (indigo, thioindigo, etc.), squarylium dyes, azurenium dyes, thiopyrylium dyes, pyrylium salts, triphenylmethane Organic pigments or dyes such as dyes, further selenium, inorganic materials such as amorphous silicon. These charge generating materials can be used alone or in combination of two or more.
Among these charge generation materials, phthalocyanine pigments, azo pigments, and perylene pigments are particularly preferable because of their high sensitivity.

  The charge generation layer is a chemical sensitizer, an optical sensitizer, an antioxidant, an ultraviolet absorber, a dispersion stabilizer, a sensitizer, a leveling agent, a plasticizer, as long as the preferable characteristics of the present invention are not impaired. An appropriate amount of one or more known additives selected from fine particles of inorganic compounds or organic compounds may be contained. These additives may be contained in the charge transport layer described later, or may be contained in both the charge generation layer and the charge transport layer.

  The chemical sensitizer and the optical sensitizer improve the sensitivity of the photoreceptor, suppress an increase in residual potential and fatigue due to repeated use, and improve electrical durability.

  Examples of chemical sensitizers include acid anhydrides such as succinic anhydride, maleic anhydride, phthalic anhydride, and 4-chloronaphthalic anhydride; cyano compounds such as tetracyanoethylene and terephthalmalondinitrile, and 4-nitrobenzaldehyde. Aldehydes; anthraquinones such as anthraquinone and 1-nitroanthraquinone; polycyclic or heterocyclic nitro compounds such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitrofluorenone; diphenoquinone compounds Examples thereof include electron-withdrawing materials and those obtained by polymerizing these electron-withdrawing materials.

  Examples of the optical sensitizer include xanthene dyes, quinoline pigments, organic photoconductive compounds such as copper phthalocyanine, triphenylmethane dyes typified by methyl violet, crystal violet, knight blue and victoria blue; erythrosin, Acridine dyes typified by rhodamine B, rhodamine 3R, acridine orange and frappeocin; thiazine dyes typified by methylene blue and methylene green; oxazine dyes typified by capri blue and meldra blue; cyanine dyes; styryl dyes; Examples include pyrylium salt dyes and thiopyrylium salt dyes.

Antioxidants can maintain sensitivity stability over a long period of time.
Antioxidants include phenolic antioxidants such as hindered phenols such as 2,6-di-t-butyl-4-methylphenol (2,6-di-t-butyl-p-cresol: BHT). , Amine antioxidants such as hindered amines, vitamin E, hydroquinone, paraphenylenediamine, arylalkanes and derivatives thereof, organic sulfur compounds, organic phosphorus compounds, etc., and these may be used alone or in combination of two or more. Can be used.

The addition amount of the antioxidant is preferably from 0.1 to 40 parts by weight, particularly preferably from 0.5 to 15 parts by weight, based on 100 parts by weight of the charge generation material.
If the addition amount of the antioxidant is less than 0.1 parts by weight, there is a possibility that sufficient effects cannot be obtained for improving the stability of the coating solution and improving the durability of the photoreceptor. On the other hand, if the amount of the antioxidant added exceeds 40 parts by weight, the photoreceptor characteristics may be adversely affected.

Leveling agents and plasticizers can improve film formability, flexibility and surface smoothness.
Examples of the leveling agent include a silicone leveling agent.
Examples of the plasticizer include dibasic acid esters such as phthalate esters, fatty acid esters, phosphate esters, chlorinated paraffins, and epoxy type plasticizers.

  Fine particles of an inorganic compound or an organic compound can enhance mechanical strength and improve electrical characteristics. Examples of such fine particles include fine particles exemplified in an intermediate layer described later.

The charge generation layer can be formed by a known dry method and wet method.
Examples of the dry method include a method of vacuum-depositing a charge generating material on the surface of a conductive support.
As a wet method, for example, a charge generating material, and optionally additives and a binder resin are dissolved or dispersed in a suitable organic solvent to prepare a coating solution for forming a charge generating layer, and this coating solution is made conductive. The method of apply | coating to the intermediate | middle layer surface formed on the support body, and then drying and removing an organic solvent is mentioned.

The binder resin can improve the mechanical strength and durability of the charge generation layer, the binding property between layers, and the like, and a resin having a binding property used in this field can be used.
Specifically, vinyl resins such as polymethyl methacrylate, polystyrene, polyvinyl chloride, polycarbonate, polyester, polyester carbonate, polysulfone, polyarylate, polyamide, methacrylic resin, acrylic resin, polyether, polyacrylamide, polyphenylene oxide, etc. Thermoplastic resin: Thermosetting resin such as phenoxy resin, epoxy resin, silicone resin, polyurethane, phenol resin, alkyd resin, melamine resin, phenoxy resin, polyvinyl butyral, polyvinyl formal, partially cross-linked products of these resins, these resins Copolymer resins containing two or more of the structural units contained in (vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, acrylo Tolyl - insulating resin such as styrene copolymer resin). These binder resins can be used alone or in combination of two or more.

The mixing ratio of the charge generation material and the binder resin is not particularly limited, but the charge generation material is usually about 10 to 99% by weight.
If the charge generation material is less than 10% by weight, the sensitivity of the photoreceptor may be lowered.
On the other hand, when the charge generation material exceeds 99% by weight, not only the film strength of the charge generation layer decreases, but also the dispersibility of the charge generation material decreases and coarse particles may increase. For this reason, surface charges other than those to be erased by exposure are reduced, and there is a risk that image defects, particularly an image fogging called black spots where toner adheres to a white background and minute black spots are formed, will increase.

  Examples of the organic solvent include aromatic hydrocarbons such as toluene, xylene, mesitylene, tetralin, diphenylmethane, dimethoxybenzene, and dichlorobenzene; halogenated hydrocarbons such as dichloromethane, dichloroethane, and tetrachloropropane; tetrahydrofuran (THF) and dioxane. , Ethers such as dibenzyl ether, dimethoxymethyl ether and 1,2-dimethoxyethane; ketones such as methyl ethyl ketone, cyclohexanone, acetophenone and isophorone; esters such as methyl benzoate, ethyl acetate and butyl acetate, and diphenyl sulfide Sulfur-containing solvents; Fluorine solvents such as hexafluoroisopropanol; aprotic polar solvents such as N, N-dimethylformamide and N, N-dimethylacetamide Etc., and these may be used alone or as a mixed solvent. A mixed solvent obtained by adding alcohols, acetonitrile, or methyl ethyl ketone to such a solvent can also be used. Among these solvents, non-halogen organic solvents are preferably used in consideration of the global environment.

Prior to dissolving or dispersing the constituent materials in the resin solution, the charge generating material may be pre-ground.
The preliminary pulverization can be performed using a general pulverizer such as a ball mill, a sand mill, an attritor, a vibration mill, or an ultrasonic disperser.
The dissolution or dispersion of the constituent materials in the resin solution can be performed using, for example, a general disperser such as a paint shaker, a ball mill, or a sand mill. At this time, it is preferable to appropriately set the dispersion conditions so that impurities are generated from the members constituting the container and the disperser due to wear and the like and are not mixed into the coating liquid.

  The application method of the coating solution for forming the charge generation layer is a baker applicator method, a bar coater method, a casting method, a spin coating method, a roll method, a blade method or the like in the case of a sheet, and a spray method or a vertical ring in the case of a drum. Method, dip coating method and the like.

Although it will not specifically limit if the temperature in the drying process of a coating film is the temperature which can remove the used organic solvent, 50-140 degreeC is suitable and 80-130 degreeC is especially preferable.
When the drying temperature is less than 50 ° C., the drying time may be long. On the other hand, if the drying temperature exceeds 140 ° C., the electrical characteristics during repeated use of the photoreceptor may deteriorate and the resulting image may deteriorate.

  The thickness of the charge generation layer is not particularly limited, but is preferably 0.05 to 5 μm, particularly preferably 0.1 to 1 μm. When the thickness of the charge generation layer is less than 0.05 μm, the light absorption efficiency is lowered, and the sensitivity may be lowered. On the other hand, if the thickness of the charge generation layer exceeds 5 μm, charge transport within the charge generation layer becomes a rate-limiting step in the process of erasing the charge on the surface of the photoreceptor, and the sensitivity may be lowered.

[Charge transport layer 4]
The charge transport layer contains, as main components, a charge transport material having the ability to accept and transport charges generated by the charge generation material and a binder resin (binder).

As the charge transport material, a compound used in this field can be used.
Specifically, poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, oxadiazole derivatives , Imidazole derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1-bis (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, pyrazoline derivatives, phenylhydrazones, hydrazone derivatives, triphenylamine series Electron donating substances such as compounds, tetraphenyldiamine compounds, triphenylmethane compounds, stilbene compounds, azine compounds having a 3-methyl-2-benzothiazoline ring;

Fluorenone derivative, dibenzothiophene derivative, indenothiophene derivative, phenanthrenequinone derivative, indenopyridine derivative, thioxanthone derivative, benzo [c] cinnoline derivative, phenazine oxide derivative, tetracyanoethylene, tetracyanoquinodimethane, promanyl, chloranil And electron accepting substances such as benzoquinone. These charge transport materials can be used alone or in combination of two or more.

The ratio E / B between the weight E of the charge transport material and the weight B of the binder resin is 10/12 to 10/25, preferably 10/16 to 10/20.
When the ratio E / B is less than 10/25, the relative amount ratio of the binder resin to the charge transport material is increased, and sufficient sensitivity may not be obtained.
On the other hand, if the ratio E / B exceeds 10/12, the printing durability of the charge transport layer and the durability of the photoreceptor may be lowered.

As the binder resin, one or more of the same binder resins as those contained in the charge generation layer can be used.
Among these resins, polycarbonate-based resins, polyarylate resins and polystyrene resins are photochemically stable, excellent in compatibility with charge transport materials, and have a volume resistance of 10 ¹³ Ω or more. It is preferable because it is excellent in electrical insulation and has excellent film forming properties and potential characteristics.

  The charge transport layer may contain an appropriate amount of the same additive as that contained in the charge generation layer, if necessary, within the range not impairing the effects of the present invention.

The charge transport layer is prepared by dissolving or dispersing a charge transport material, a binder resin and other additives as required in an appropriate organic solvent to prepare a charge transport layer forming coating solution. It can be formed by applying to the surface of the layer and then drying to remove the organic solvent. More specifically, for example, by dissolving or dispersing a charge transport material and other additives as required in a resin solution obtained by dissolving a binder resin in an organic solvent, a charge transport layer forming coating solution is obtained. Prepare.
Other processes and conditions are in accordance with the formation of the charge generation layer.

  Although the film thickness of a charge transport layer is not specifically limited, 10-60 micrometers is preferable and 10-40 micrometers is especially preferable. If the thickness of the charge transport layer is less than 10 μm, the charge retention ability may be reduced. Conversely, if the thickness of the charge transport layer is more than 60 μm, sharpness decreases and residual potential increases, There is a risk that image deterioration will occur remarkably.

[Single layer type photosensitive layer 5 ']
The single-layer type photosensitive layer contains a charge generation material, a charge transport material, and a binder resin (binder) as main components.
The single-layer type photosensitive layer may contain an appropriate amount of the same additive as that contained in the charge generation layer, if necessary, within the range not impairing the effects of the present invention.

A single-layer type photosensitive layer is prepared by dissolving and / or dispersing a charge generation material, a charge transport material and, if necessary, other additives in an appropriate organic solvent to prepare a single-layer type photosensitive layer forming coating solution, This coating liquid can be formed by applying to the surface of the intermediate layer formed on the conductive support and then drying to remove the organic solvent.
Other processes and conditions are in accordance with the formation of the charge generation layer and the charge transport layer.

  The film thickness of the single-layer type photosensitive layer is not particularly limited, but is preferably 10 to 100 μm, particularly preferably 15 to 50 μm. If the film thickness of the single-layer type photosensitive layer is less than 10 μm, the charge holding ability on the surface of the photoreceptor may be lowered, and if the film thickness of the single-layer type photosensitive layer exceeds 100 μm, the productivity may be lowered. is there.

[Protective layer (not shown)]
The photoreceptor of the present invention may have a protective layer (not shown) on the surface of the multilayer photosensitive layer 5 and the single-layer photosensitive layer 5 ′.
The protective layer has functions of improving the abrasion of the photosensitive layer and preventing chemical adverse effects caused by ozone, nitrogen oxides, and the like.

The protective layer is prepared by, for example, preparing a protective layer-forming coating solution by dissolving or dispersing a binder resin in an appropriate organic solvent and, if necessary, an additive such as an antioxidant or an ultraviolet absorber. The coating liquid can be applied to the surface of a single layer type photosensitive layer or a multilayer type photosensitive layer, and the organic solvent can be removed by drying.
Other processes and conditions are in accordance with the formation of the charge generation layer.

  Although the film thickness of a protective layer is not specifically limited, 0.5-10 micrometers is preferable and 1-5 micrometers is especially preferable. If the thickness of the surface protective layer 5 is less than 0.5 μm, the surface resistance of the photoreceptor is inferior and the durability may be insufficient. Conversely, if it exceeds 10 μm, the resolution of the photoreceptor may be reduced. There is.

  The image forming apparatus of the present invention is formed by exposure, the photosensitive member of the present invention, a charging unit for charging the photosensitive member, an exposure unit for exposing the charged photosensitive member to form an electrostatic latent image, and exposure. Developing means for developing the electrostatic latent image to form a toner image; transfer means for transferring the toner image formed by development onto a recording medium; and transferring the transferred toner image onto the recording material. The image forming apparatus includes at least a fixing unit that fixes and forms an image, a cleaning unit that removes and collects toner remaining on the photoconductor, and a static elimination unit that neutralizes surface charge remaining on the photoconductor.

The image forming apparatus of the present invention will be described with reference to the drawings, but is not limited to the following description.
FIG. 7 is a schematic side view showing the configuration of the image forming apparatus of the present invention.
The image forming apparatus 20 in FIG. 7 includes a photoconductor 21 of the present invention (for example, any one of the photoconductors in FIGS. 4 to 6), a charging unit (charger) 24, an exposure unit 28, and a developing unit ( Development unit) 25, transfer unit (transfer unit) 26, cleaning unit (cleaner) 27, fixing unit (fixing unit) 31, and charge eliminating unit (not shown, attached to cleaning unit 27). Composed. Reference numeral 30 indicates a transfer sheet.

  The photosensitive member 21 is rotatably supported by the main body of the image forming apparatus 20 (not shown), and is driven to rotate in the direction of the arrow 23 around the rotation axis 22 by a driving unit (not shown). The drive means includes, for example, an electric motor and a reduction gear, and transmits the driving force to a conductive support constituting the core of the photoconductor 21, thereby rotating the photoconductor 21 at a predetermined peripheral speed. . The charger 24, the exposure unit 28, the developing unit 25, the transfer unit 26, and the cleaner 27 are arranged in this order along the outer peripheral surface of the photoconductor 21 from the upstream side in the rotation direction of the photoconductor 21 indicated by the arrow 23. It is provided toward the side.

  The charger 24 is a charging unit that charges the outer peripheral surface of the photoconductor 21 to a predetermined potential. Specifically, for example, the charger 24 is realized by a contact-type charging roller 24a, a charging brush, or a charger wire such as a corotron or a scorotron. Reference numeral 24b shows a bias power source.

  The exposure unit 28 includes, for example, a semiconductor laser as a light source, and is charged by irradiating light 28 a such as a laser beam output from the light source between the charger 24 and the developing unit 25 of the photosensitive member 21. The outer peripheral surface of the photoconductor 21 is exposed according to image information. The light 28a is repeatedly scanned in the main scanning direction in the direction in which the rotation axis 22 of the photoconductor 21 extends, and accordingly, electrostatic latent images are sequentially formed on the surface of the photoconductor 21.

  The developing unit 25 is a developing unit that develops an electrostatic latent image formed on the surface of the photoreceptor 21 by exposure with a developer. The developing unit 25 is provided facing the photoreceptor 21, and applies toner to the outer peripheral surface of the photoreceptor 21. A developing roller 25a to be supplied and a casing 25b for supporting the developing roller 25a so as to be rotatable around a rotation axis parallel to the rotation axis 22 of the photosensitive member 21 and containing a developer containing toner in the internal space thereof.

  The transfer device 26 supplies a toner image, which is a visible image formed on the outer peripheral surface of the photoconductor 21 by development, between the photoconductor 21 and the transfer device 26 from the direction of the arrow 29 by a conveying unit (not shown). It is a transfer means for transferring onto the transfer paper 30 as a recording medium. The transfer unit 26 is, for example, a non-contact type transfer unit that includes a charging unit and transfers the toner image onto the transfer paper 30 by applying a charge having a polarity opposite to that of the toner to the transfer paper 30.

  The cleaner 27 is a cleaning unit that removes and collects toner remaining on the outer peripheral surface of the photoconductor 21 after the transfer operation by the transfer device 26, and includes a cleaning blade 27 a that peels off toner remaining on the outer peripheral surface of the photoconductor 21, and a cleaning device. A recovery casing 27b for storing the toner separated by the blade 27a. The cleaner 27 is provided together with a charge eliminating lamp (not shown).

  Further, the image forming apparatus 20 is provided with a fixing device 31 as fixing means for fixing the transferred image on the downstream side where the transfer paper 30 that has passed between the photoreceptor 21 and the transfer device 26 is conveyed. . The fixing device 31 includes a heating roller 31a having a heating unit (not shown), and a pressure roller 31b that is provided to face the heating roller 31a and is pressed by the heating roller 31a to form a contact portion.

  The image forming operation by the image forming apparatus 20 is performed as follows. First, when the photosensitive member 21 is rotationally driven in the direction of the arrow 23 by the driving means, the photosensitive member 24 is provided by the charger 24 provided on the upstream side in the rotational direction of the photosensitive member 21 with respect to the image forming point of the light 28a by the exposure means 28. The surface of 21 is uniformly charged to a predetermined positive or negative potential.

  Next, light 28 a corresponding to image information is irradiated from the exposure unit 28 to the surface of the photoconductor 21. With this exposure, the surface charge of the portion irradiated with the light 28a is removed from the photosensitive member 21, and a difference occurs between the surface potential of the portion irradiated with the light 28a and the surface potential of the portion not irradiated with the light 28a. An electrostatic latent image is formed.

  Next, toner is supplied to the surface of the photosensitive member 21 on which the electrostatic latent image is formed from a developing unit 25 provided on the downstream side in the rotation direction of the photosensitive member 21 with respect to the image forming point of the light 28a by the exposure unit 28. The electrostatic latent image is developed to form a toner image.

  In synchronization with the exposure of the photosensitive member 21, the transfer paper 30 is supplied between the photosensitive member 21 and the transfer device 26. The transfer device 26 applies a charge having a polarity opposite to that of the toner to the supplied transfer paper 30, and the toner image formed on the surface of the photoreceptor 21 is transferred onto the transfer paper 30.

  Next, the transfer paper 30 onto which the toner image has been transferred is conveyed to the fixing device 31 by the conveying means, and is heated and pressurized when passing through the contact portion between the heating roller 31a and the pressure roller 31b of the fixing device 31. The toner image is fixed on the transfer paper 30 and becomes a robust image. The transfer paper 30 on which the image is formed in this way is discharged to the outside of the image forming apparatus 20 by the conveying means.

  On the other hand, the toner remaining on the surface of the photoconductor 21 even after the transfer of the toner image by the transfer unit 26 is separated from the surface of the photoconductor 21 by the cleaner 27 and collected. The charge on the surface of the photoconductor 21 from which the toner has been removed in this manner is removed by the light from the static elimination lamp, and the electrostatic latent image on the surface of the photoconductor 21 disappears. Thereafter, the photosensitive member 21 is further driven to rotate, and a series of operations starting from charging is repeated to continuously form images.

  EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1
First, a product of Lion Co., Ltd. as a surfactant (neutral detergent) was added to ion-exchanged water (about 1 μS / cm), and a product name: Sunwash FM-20 was added to prepare a 5 wt% aqueous solution, which was used as a cleaning solution. .
The obtained cleaning liquid was put in a first cleaning tank (300 mm × 300 mm × depth 500 mm), and an aluminum cylindrical conductive support body having an outer diameter of 30 mm × length of 340 mm × thickness of 0.8 mm was immersed in this, Ultrasonic vibration was applied at a frequency of 40 kHz and an output of 600 W for 2 minutes.
Thereafter, the cylindrical conductive support is taken out of the first cleaning tank and immersed in a second cleaning tank (same type as the first cleaning tank) containing only ion exchange water (about 1 μS / cm). Ultrasonic vibration was applied for 2 minutes under the same conditions.
Next, the cylindrical conductive support is taken out of the second cleaning tank and immersed in a third cleaning tank (same type as the first cleaning tank) containing only pure water (0.8 to 1.0 μS / cm). Ultrasonic vibration was applied for 2 minutes under the same conditions as in the case of one washing tank.
Next, the cylindrical conductive support was taken out from the third cleaning tank and immersed in a fourth cleaning tank (same type as the first cleaning tank) containing warm pure water controlled at a temperature of 42 ± 5 ° C. for 1 minute, and then a speed of 6 mm / It was slowly pulled up at s (= mm / sec).
Next, the cylindrical conductive support was dried at a temperature of 120 ° C. for 30 minutes.

Using a paint shaker, the following components were dispersed for 6 hours to prepare an intermediate layer coating solution.
Dendritic titanium oxide fine particles (average primary particle size: minor axis 40-70 nm, major axis 200-300 nm) surface-treated with aluminum oxide (Al ₂ O ₃ ) and zirconium dioxide (ZrO ₂ ) as conductive fine particles , Manufactured by Ishihara Sangyo Co., Ltd., product name: TTO-D-1): 12 parts by weight Aqueous polyacrylic polyol as resin (solid content: 45%, OH value: 80, manufactured by DIC Corporation, product name: Burnock WE -300): 8.4 parts by weight Blocked isocyanate compound (solid content: 40%, NCO content: 5.4%, manufactured by Mitsui Chemicals Polyurethanes, product name: Takenate WB-920): 10.5 parts by weight Foaming agent (polyether foam suppressor, manufactured by San Nopco, product name: SN deformer 470): 0.08 parts by weight Dispersion stabilizer (produced by San Nopco, manufactured by Product name: Rome PWA-40): 0.03 parts by weight Water: 69 parts by weight The isocyanate group of the blocked isocyanate compound is in a molar ratio of 1.0 to the active hydrogen-containing group of the resin, and the conductive fine particles (P) are The weight ratio (P / R) was 6/4 with respect to the crosslinked resin (total of blocked isocyanate compound and resin: R).
The obtained coating solution for forming an intermediate layer is filled in a coating tank, the washed conductive support is immersed and then pulled up, and the obtained coating film is dried and cured at a temperature of 150 ° C. for 30 minutes to obtain a film thickness. An intermediate layer of 1.0 μm was formed.

Next, using a paint shaker, the following components were dispersed for 1 hour to prepare a charge generation layer coating solution.
Y-type oxotitanium phthalocyanine as a charge generating substance (manufactured by Sanyo Dye Co., Ltd.): 2 parts by weight Polyvinyl butyral resin (product of Sekisui Chemical Co., Ltd., product name: ESREC B BM-S) as a binder resin: 1 weight Part: 97 parts by weight of methyl ethyl ketone as an organic solvent The obtained charge generation layer coating solution was applied onto the previously formed intermediate layer by the same dip coating method as that for the intermediate layer, and then naturally dried to obtain a film thickness A 0.4 μm charge generation layer was formed.

Next, the following components were dissolved in the following organic solvent to prepare a charge transport layer coating solution.
Triphenylamine compound represented by the following structural formula (1) as a charge transport material: 10 parts by weight Polycarbonate resin (product name: Iupilon Z400, manufactured by Mitsubishi Engineering Plastics) as a binder resin: 18 parts by weight:
2,6-di-t-butyl-4-methylphenol as an antioxidant: 0.5 part by weight Dimethylpolysiloxane as a leveling agent (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KF-96): 0.004 parts by weight Tetrahydrofuran (THF) as an organic solvent: 110 parts by weight The obtained charge transport layer coating solution was applied onto the charge generation layer formed earlier by the same dip coating method as that for the intermediate layer. Then, the obtained coating film was dried at 130 ° C. for 1 hour to form a charge transport layer having a thickness of 23 μm.
The photoreceptor of Example 1 was produced as described above.

(Example 2)
A photoconductor of Example 2 was produced in the same manner as Example 1 except that the intermediate layer coating solution was prepared with the following components.
Dendritic titanium oxide fine particles (average primary particle size: minor axis 40-70 nm, major axis 200-300 nm) surface-treated with aluminum oxide (Al ₂ O ₃ ) and zirconium dioxide (ZrO ₂ ) as conductive fine particles , Manufactured by Ishihara Sangyo Co., Ltd., product name: TTO-D-1): 12 parts by weight Polyether polyol as a resin (solid content: 35%, OH value: 60, manufactured by Nippon Polyurethane Industry Co., Ltd., product name: AQD -473): 14.3 parts by weight Block isocyanate compound (solid content: 42%, NCO content: 7.5%, manufactured by Nippon Polyurethane Industry Co., Ltd., developed product name: BWD-102): 7.1 parts by weight Agent (Polyether antifoam, manufactured by San Nopco, product name: SN deformer 470): 0.08 parts by weight Water: 67 parts by weight Block isocyanate The isocyanate groups of the product are in a molar ratio of 1.0 to the active hydrogen-containing groups of the resin, and the conductive fine particles (P) are 6/4 to the cross-linked resin (total of blocked isocyanate compounds and resins: R). The weight ratio (P / R).

(Example 3)
A photoconductor of Example 3 was produced in the same manner as in Example 1 except that the intermediate layer coating solution was prepared with the following components.
Titanium oxide fine particles as inorganic oxide fine particles (average primary particle size: 35 nm, manufactured by Teika Co., Ltd., product name: MT-500SAS): 12 parts by weight Polyvinyl acetal as resin (solid content: 20%, OH value: 960, manufactured by Sekisui Chemical Co., Ltd., product name: KW-1): 4.0 parts by weight Block isocyanate compound (solid content: 70%, NCO content: 7.9%, manufactured by Asahi Kasei Chemicals Corporation, developed product name : X1248) 10.3 parts by weight Antifoaming agent (oil compound type, manufactured by San Nopco Co., Ltd., product name: SN deformer 777): 0.08 parts by weight Dispersion stabilizer (manufactured by Sanyo Chemical Industries, product name: CALIBON L- 400): 0.03 part by weight Water: 74 part by weight The isocyanate group of the blocked isocyanate compound is 1.0 with respect to the active hydrogen-containing group of the resin. In terms of molar ratio, the inorganic oxide fine particles (P) were in a 6/4 weight ratio (P / R) to the cross-linked resin (total of blocked isocyanate compound and resin: R).

Example 4
A photoconductor of Example 4 was produced in the same manner as in Example 1 except that the intermediate layer coating solution was prepared with the following components.
Zinc oxide fine particles (average primary particle size: 35 nm, manufactured by Sakai Chemical Industry Co., Ltd., product name: FINEX30): 12 parts by weight of water-soluble cellulose (OH value: 360, Shin-Etsu Chemical Co., Ltd.) as a resin Product name: Metrolose 65SH-50): 0.96 parts by weight Block isocyanate compound (solid content: 37.5%, NCO content: 3.7%, manufactured by Sumika Bayer Urethane Co., Ltd., product name: Bihijur VPLS2310): 18.8 parts by weight Antifoaming agent (polyether antifoam, manufactured by San Nopco, product name: SN deformer 470): 0.08 parts by weight Water: 68 parts by weight The isocyanate group of the blocked isocyanate compound is At a molar ratio of 1.0 to the active hydrogen-containing group of the resin, the conductive fine particles (P) are crosslinked resin (block isocyanate). Sulfonate compounds and the total of the resin were: 6/4 weight ratio with respect to R) (P / R).

(Example 5)
A photoconductor of Example 5 was produced in the same manner as in Example 1 except that the intermediate layer coating solution was prepared with the following components.
Zinc oxide fine particles as conductive fine particles (average primary particle size: 35 nm, manufactured by Sakai Chemical Industry Co., Ltd., product name: FINEX30): 12 parts by weight Water-soluble nylon as resin (solid content: 20%, NH content) : 10%, manufactured by Nagase ChemteX Corporation, product name: Toresin FS-350): 8.8 parts by weight Block isocyanate compound (solid content: 45%, NCO content: 7.0%, manufactured by Mitsui Chemicals Polyurethanes, Inc.) , Product name: Takenate WB-820): 13.9 parts by weight Antifoaming agent (polyether antifoam, manufactured by San Nopco, product name: SN deformer 470): 0.08 parts by weight Dispersion stabilizer (San Nopco stock) Product name: Roma PWA-40): 0.03 part by weight Water: 65 part by weight The isocyanate group of the blocked isocyanate compound is the active part of the resin. At a molar ratio of 1.0 with respect to the hydrogen-containing group, the conductive fine particles (P) have a weight ratio (P / R) of 6/4 with respect to the cross-linked resin (total of blocked isocyanate compound and resin: R). there were.

(Example 6)
A photoconductor of Example 6 was produced in the same manner as in Example 1 except that the intermediate layer coating solution was prepared with the following components.
Dendritic titanium oxide fine particles (average primary particle size: minor axis 40-70 nm, major axis 200-300 nm) surface-treated with aluminum oxide (Al ₂ O ₃ ) and zirconium dioxide (ZrO ₂ ) as conductive fine particles , Manufactured by Ishihara Sangyo Co., Ltd., product name: TTO-D-1): 12 parts by weight Polyether polyol as a resin (solid content: 35%, OH value: 60, manufactured by Nippon Polyurethane Industry Co., Ltd., product name: AQD -473): 18.4 parts by weight Block isocyanate compound (solid content: 42%, NCO content: 7.5%, manufactured by Nippon Polyurethane Industry Co., Ltd., developed product name: BWD-102): 3.7 parts by weight Agent (Polyether antifoam, manufactured by San Nopco, product name: SN deformer 470): 0.08 parts by weight Water: 66 parts by weight Block isocyanate The isocyanate group of the product is a molar ratio of 0.4 to the active hydrogen-containing group of the resin, and the conductive fine particles (P) are 6/4 to the cross-linked resin (total of blocked isocyanate compound and resin: R). The weight ratio (P / R).

(Example 7)
A photoconductor of Example 7 was produced in the same manner as in Example 1 except that the intermediate layer coating solution was prepared with the following components.
Dendritic titanium oxide fine particles (average primary particle size: minor axis 40-70 nm, major axis 200-300 nm) surface-treated with aluminum oxide (Al ₂ O ₃ ) and zirconium dioxide (ZrO ₂ ) as conductive fine particles , Manufactured by Ishihara Sangyo Co., Ltd., product name: TTO-D-1): 12 parts by weight Polyether polyol as a resin (solid content: 35%, OH value: 60, manufactured by Nippon Polyurethane Industry Co., Ltd., product name: AQD -473): 11.7 parts by weight Block isocyanate compound (solid content: 42%, NCO content: 7.5%, manufactured by Nippon Polyurethane Industry Co., Ltd., developed product name: BWD-102): 9.3 parts by weight Agent (Polyether antifoam, manufactured by San Nopco, product name: SN deformer 470): 0.08 parts by weight Water: 67 parts by weight Block isocyanate The isocyanate groups of the product are in a molar ratio of 1.6 to the active hydrogen-containing groups of the resin, and the conductive fine particles (P) are 6/4 to the cross-linked resin (total of blocked isocyanate compounds and resins: R). The weight ratio (P / R).

(Example 8)
The photosensitive member of Example 8 was prepared in the same manner as in Example 1 except that two intermediate layers were formed as described below. The following components were stirred and mixed to form a first intermediate layer coating solution (conductive No fine particles were prepared.
Polyether polyol (solid content: 35%, OH number: 60, manufactured by Nippon Polyurethane Industry Co., Ltd., product name: AQD-473): 17.9 parts by weight Block isocyanate compound (solid content: 42%, NCO) Content: 7.5%, manufactured by Nippon Polyurethane Industry Co., Ltd., developed product name: BWD-102): 8.9 parts by weight Water: 73 parts by weight The isocyanate group of the blocked isocyanate compound is based on the active hydrogen-containing group of the resin. The molar ratio was 1.0.
Filling the coating tank with the obtained first intermediate layer forming coating liquid, immersing the washed conductive support, then pulling up, drying and curing the resulting coating film at a temperature of 150 ° C. for 30 minutes, A first intermediate layer (blocking layer) having a thickness of 0.5 μm was formed.

Next, using a paint shaker, the following components were dispersed for 6 hours to prepare a second intermediate layer coating solution. Titanium oxide fine particles (average primary particle size: 250 nm, Ishihara Sangyo Co., Ltd.) as conductive fine particles Company-made, product name: CR-EL): 14 parts by weight Polyether polyol as resin (solid content: 35%, OH value: 60, manufactured by Nippon Polyurethane Industry Co., Ltd., product name: AQD-473): 10. 7 parts by weight Block isocyanate compound (solid content: 42%, NCO content: 7.5%, manufactured by Nippon Polyurethane Industry Co., Ltd., developed product name: BWD-102): 5.4 parts by weight Antifoaming agent (polyether-based inhibitor) Foaming agent, manufactured by San Nopco Co., Ltd., product name: SN deformer 470): 0.08 part by weight Water: 70 part by weight The isocyanate group of the blocked isocyanate compound is the active part of the resin. At a molar ratio of 1.0 with respect to the hydrogen-containing group, the conductive fine particles (P) are in a weight ratio (P / R) of 7/3 with respect to the cross-linked resin (total of blocked isocyanate compound and resin: R). there were.
The obtained coating solution for forming the second intermediate layer is filled in a coating tank, and is applied onto the first intermediate layer previously formed by the same dip coating method as that for the first intermediate layer. The film was dried and cured at 150 ° C. for 30 minutes to form a second intermediate layer (conductive layer) having a thickness of 10 μm.

  The photoconductors obtained in Examples 1 to 8 were incorporated into a commercially available digital copying machine (manufactured by Sharp Corporation, model: MX-M450) as an image forming apparatus, and image characteristics were evaluated. As a result, a good image having a sufficient density and no other image defects was obtained without any background fog. Also, good images were obtained over time of use.

(Example 9-1)
Before drying the cylindrical conductive support, that is, after pulling up the cylindrical conductive support from the fourth washing tank, draining the cylindrical conductive support with the draining device shown in FIG. A photoconductor of Example 9-1 was produced in the same manner as in Example 1 except that the film was dried for 15 minutes (30 minutes in Example 1).
Specifically, after pulling up the cylindrical conductive support from the fourth cleaning tank, the upper and lower end surfaces of the cylindrical conductive support 1 are connected to the conductive support holding part (holder) 51 of the draining device shown in FIG. 52. Next, the rotating means (motor) M was rotated at a rotational speed of 200 rpm for 20 seconds to drain water. Next, the cylindrical conductive support was dried at a temperature of 120 ° C. for 15 minutes, and then a photoreceptor of Example 9-1 was produced in the same manner as in Example 1.

(Examples 9-2 to 9-8)
The photoconductors of Examples 9-2 to 9-8 were prepared in the same manner as in Example 9-1 except that the photoconductors were prepared in the same manner as in Examples 2 to 8 instead of the same as in Example 1. Produced.

  The photoreceptors obtained in Examples 9-1 to 9-8 were incorporated in a commercially available digital copying machine (manufactured by Sharp Corporation, model: MX-M450) as an image forming apparatus, and image characteristics were evaluated. As a result, a good image having a sufficient density and no other image defects was obtained without any background fog. Also, good images were obtained over time of use.

(Example 10-1)
After the cylindrical conductive support was immersed in the fourth cleaning tank, the cylindrical conductive support was passed through the opening of the draining member in the draining device shown in FIGS. 2 and 3 and pulled up at a speed of 10 mm / s to drain the water. A photoconductor of Example 10-1 was produced in the same manner as in Example 1 except that the film was dried at 120 ° C. for 15 minutes (30 minutes in Example 1).
Specifically, after the cylindrical conductive support is immersed in the fourth cleaning tank, the cylindrical conductive support 1 is passed through the opening of the draining member 40 in the draining apparatus shown in FIGS. 2 and 3, and the speed is 10 mm / s. Pulled up and drained. Next, the cylindrical conductive support was dried at a temperature of 120 ° C. for 15 minutes, and then a photoconductor of Example 10-1 was produced in the same manner as in Example 1.
The draining member 40 is formed by processing a 0.5 mm thick polyurethane sheet having a hardness of A70 ± 2 degrees (JIS K6253 durometer type A) into a diameter of 50 mm and punching into a concentric circle with a diameter of 29 mm. As shown in FIG. 2, a pair of aluminum alloy blocks 41 and 42 each having a diameter of 60 mm and a thickness of 10 mm, which were punched into a concentric circle having a diameter of 40 mm, were used. The blocks 41 and 42 were fixed to fixing means (not shown), and further held and used by holding means (not shown).

(Examples 10-2 to 10-8)
The photoconductors of Examples 10-2 to 10-8 were prepared in the same manner as in Example 10-1, except that photoconductors were produced in the same manner as in Examples 2 to 8 instead of the same as in Example 1. Produced.

  The photoreceptors obtained in Examples 10-1 to 9-8 were incorporated into a commercially available digital copying machine (manufactured by Sharp Corporation, model: MX-M450) as an image forming apparatus, and image characteristics were evaluated. As a result, a good image having a sufficient density and no other image defects was obtained without any background fog. Also, good images were obtained over time of use.

(Comparative Example 1)
A photoreceptor of Comparative Example 1 was produced in the same manner as in Example 1 except that the intermediate layer coating solution (organic solvent system, no curing) was prepared with the following components.
Dendritic titanium oxide fine particles (average primary particle size: minor axis 40-70 nm, major axis 200-300 nm) surface-treated with aluminum oxide (Al ₂ O ₃ ) and zirconium dioxide (ZrO ₂ ) as conductive fine particles Ishihara Sangyo Co., Ltd., product name: TTO-D-1): 6 parts by weight Copolymer nylon as a resin (product name: Amilan CM8000): 4 parts by weight Methanol as an organic solvent: 50 parts by weight and 1,3-dioxolane: 40 parts by weight

(Test Example 1)
Comparative Example 1, Examples 1-8, and Example 9 except that the drying time after washing the conductive support was changed to 0 minutes (no drying), 15 minutes, 30 minutes, 45 minutes, and 60 minutes, respectively. -1 and Example 10-5, 20 photoconductors were produced.
The obtained photoreceptor is incorporated into a commercially available digital copying machine (Sharp Co., Ltd., model: MX-M450), which is an image forming apparatus, and an image is output to produce a good image without image defects. The number of bodies (non-defective) was counted. The obtained results are shown in Table 1.

  From the results of Table 1, when the intermediate layer is formed using a conventional organic solvent coating solution after washing the cylindrical conductive support with water (Comparative Example 1), sufficient drying is performed after washing. It turns out that it is necessary. On the other hand, when the intermediate layer is formed using a coating solution of an aqueous medium (Examples 1 to 8, Example 9-1 and Example 10-5), a good photoreceptor can be obtained even after drying for a short time. I understand that In addition, when the cylindrical conductive support is washed with water and then drained (Example 9-1 and Example 10-5), it can be seen that a good photoreceptor can be obtained even by drying in a shorter time.

(Comparative Example 2)
Cylindrical conductive support was immersed in a cleaning tank containing trichloroethane, ultrasonic vibration was applied for 2 minutes at a frequency of 40 kHz and an output of 600 W, and after lifting, it was dried at room temperature for several minutes, and the intermediate layer of Comparative Example 1 A photoreceptor of Comparative Example 2 was prepared in the same manner as in Example 1 except that the intermediate layer was formed using the coating liquid for coating (cleaning of organic solvent, coating liquid for organic solvent-based interlayer, no curing) .

(Comparative Example 3)
The cylindrical conductive support was immersed in a washing tank containing trichloroethane, and subjected to ultrasonic vibration for 2 minutes at a frequency of 40 kHz and an output of 600 W. After being pulled up and dried at room temperature for several minutes, and the intermediate layer of Example 1 A photoreceptor of Comparative Example 3 was prepared in the same manner as in Example 1 except that the intermediate layer was formed using the coating liquid for coating (with organic solvent cleaning, aqueous intermediate coating liquid, and curing).

(Test Example 2)
The photoreceptors obtained in Comparative Examples 1 to 3 and Example 1 were incorporated into a commercially available digital copying machine (Sharp Co., Ltd., model: MX-M450) as an image forming apparatus, and an image was output. It was good. In Comparative Examples 2 and 3, the washing performance of the cylindrical conductive support is high, and almost no drying time is required after washing. However, the organic solvent used in these cases has a strong adverse effect on the human body and the environment and is removed. In addition, there is a problem that a large-scale device is required separately.
The results obtained are summarized in Table 2.

It is a schematic diagram which shows an example of the draining device of this invention. It is a model exploded view which shows the other example of the draining apparatus of this invention. It is a schematic diagram which shows the other example of the draining apparatus of this invention. FIG. 3 is a schematic cross-sectional view illustrating a configuration of a main part of the photoconductor of the present invention. FIG. 3 is a schematic cross-sectional view illustrating a configuration of a main part of the photoconductor of the present invention. FIG. 3 is a schematic cross-sectional view illustrating a configuration of a main part of the photoconductor of the present invention. 1 is a schematic side view illustrating a configuration of an image forming apparatus of the present invention.

Explanation of symbols

1 conductive support 2 intermediate layer (undercoat layer)
3 Charge Generation Layer 4 Charge Transport Layer 5 Multilayer Type Photosensitive Layer 5 ′ Single Layer Type Photosensitive Layer

20 Image forming apparatus 22 Rotating axis 23, 29 Arrow 24 Charging means (charger)
24a Charging roller 24b Bias power supply 25 Developing means (developer)
25a Developing roller 25b Casing 26 Transfer means (transfer device)
27 Cleaning means (cleaner)
27a Cleaning blade 27b Recovery casing 28 Exposure means 28a Light 30 Transfer paper 31 Fixing means (fixing device)
31a Heating roller 31b Pressure roller 40 Draining member (resin blade)
41, 42 Water draining member holding part 51, 52 Conductive support holding part (holder)
M Rotating means (motor)

Claims (17)

A washing step of washing the conductive support with water;
An intermediate layer forming step of forming an intermediate layer on the washed conductive support using an intermediate layer coating solution made of an aqueous medium;
And a photosensitive layer forming step of forming a photosensitive layer on the formed intermediate layer. A method for producing an electrophotographic photoreceptor having an organic photosensitive layer.   The said washing | cleaning process consists of immersing the said electroconductive support body in the said water, applying an ultrasonic wave, and then pulling up the said electroconductive support body from the said water at a speed | rate of 2-10 mm / s. A method for producing an electrophotographic photoreceptor.   The method for producing an electrophotographic photosensitive member according to claim 1, wherein the washing step uses water having a temperature of 25 to 50 ° C. 4.   The method for producing an electrophotographic photosensitive member according to claim 1, wherein the cleaning step uses pure water having a conductivity of 1 μS / cm or less.   The method for producing an electrophotographic photosensitive member according to any one of claims 1 to 4, further comprising a preliminary cleaning step of cleaning the conductive support with water containing a surfactant before the cleaning step.   The electrophotographic photosensitive member according to any one of claims 1 to 5, further comprising a draining step of removing water adhering to the conductive support between the cleaning step and the intermediate layer forming step. Production method.   The draining step rotates the conductive support and scatters the water by centrifugal force, or moves the resin blade while pressing the conductive support on the conductive support. The method for producing an electrophotographic photosensitive member according to claim 6, comprising removing the water adhering to the surface.   The method further includes a drying step of drying the conductive support with hot air having a temperature of 95 to 130 ° C. between the washing step and the intermediate layer forming step and, when being subjected to the draining step, thereafter. Item 8. The method for producing an electrophotographic photosensitive member according to any one of Items 1 to 7.   The intermediate layer forming step comprises forming an intermediate layer by applying a thermosetting treatment after applying the intermediate layer coating solution on the conductive support, and the intermediate layer coating solution is The electrophotography according to any one of claims 1 to 8, comprising a blocked isocyanate compound, a resin having two or more active hydrogen-containing groups capable of reacting with an isocyanate group in the blocked isocyanate compound, and an aqueous medium. A method for producing a photoreceptor.   The method for producing an electrophotographic photosensitive member according to claim 9, wherein the active hydrogen-containing group is a hydroxyl group or an amide group.   The method for producing an electrophotographic photosensitive member according to claim 9 or 10, wherein the isocyanate group is present in the blocked isocyanate compound in a molar ratio of 0.5 to 1.5 with respect to the active hydrogen-containing group.   The method for producing an electrophotographic photosensitive member according to any one of claims 9 to 11, wherein the blocked isocyanate compound has a structure in which hexamethylene diisocyanate or isophorone diisocyanate is blocked with an oxime or lactam blocking agent.   The said resin is any one of Claims 9-12 selected from polyether polyol resin, polyester polyol resin, polyacryl polyol resin, polyvinyl alcohol resin, polyvinyl acetal resin, cellulose, and polyamide resin. A process for producing an electrophotographic photoreceptor according to 1.   The method for producing an electrophotographic photosensitive member according to claim 9, wherein the intermediate layer coating solution further contains inorganic oxide fine particles.   The method for producing an electrophotographic photosensitive member according to claim 14, wherein the inorganic oxide fine particles are fine particles of titanium oxide or zinc oxide.   An electrophotographic photosensitive member obtained by the method for producing an electrophotographic photosensitive member according to claim 1.   17. The electrophotographic photosensitive member according to claim 16, a charging means for charging the electrophotographic photosensitive member, an exposure means for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image, and formed by exposure. Developing means for developing the electrostatic latent image formed thereon to form a toner image; transfer means for transferring the toner image formed by development onto a recording material; and transferring the transferred toner image onto the recording material At least a fixing unit that forms an image by fixing the toner, a cleaning unit that removes and collects toner remaining on the electrophotographic photosensitive member, and a neutralizing unit that neutralizes surface charges remaining on the electrophotographic photosensitive member. An image forming apparatus.

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