JP2575262B2 - Electrophotographic photoreceptor and method of manufacturing the electrophotographic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member and a method for producing the same, and more particularly, to an electrophotographic photosensitive member having a conductive support and an intermediate layer washed by a specific method, and a method for producing the same.

[0002]

2. Description of the Related Art Generally, an electrophotographic photosensitive member is manufactured by forming a photosensitive layer on a conductive support. Examples of the conductive support used include aluminum, copper, iron, brass, and metals such as stainless steel and alloys.
Aluminum alloys, which are excellent in workability and dimensional stability, are most widely used. Usually, these conductive supports are subjected to processing such as rolling, casting and cutting in accordance with the purpose of use. When processing, oil-based substances (kerosene and polybutene, etc.) such as processing oil, cutting oil and rust-preventive oil are used, so the oil-based substances remain on the surface of the support after processing. Also, cutting powder during processing, dust in the air, fingerprints of humans, and the like often adhere.

[0003] Even if an attempt is made to provide a photosensitive layer on a substrate in this state, a uniform layer cannot be formed and the photosensitive member cannot be formed. Even if the photosensitive layer can be formed, this photosensitive member is used. Images obtained by an electrophotographic apparatus (such as a copying machine, a laser beam printer, an LED printer, a liquid crystal shutter printer, and a facsimile) are of poor quality.

Therefore, when manufacturing an electrophotographic photosensitive member, it is necessary to sufficiently wash the support.

Conventionally, to wash the support of an electrophotographic photoreceptor, halogenated hydrocarbons (trichloroethylene,
Trichloroethane, dichloromethane or carbon tetrachloride) are used in terms of degreasing, nonflammability and quick drying. Other methods using acids and alkalis are also known. Further, as a dry method, there is a method of irradiating ozone, ultraviolet rays, or the like to disperse the attached matter, thereby performing cleaning.

[0006] However, organic solvents such as halogenated hydrocarbon solvents may adversely affect not only the human body but also the local environment. Also, when an acid or an alkali is used, there is a possibility that a neutralization step is required or that the support surface is corroded. In the method using ozone, ozone itself may have a bad influence on the human body.Not only this method, but also large-scale facilities are required to solve the problems, and the installation place and cost are large. I need.

Therefore, washing the support with water is disclosed in Japanese Patent Application Laid-Open No. 58-14841 and Japanese Patent Application Laid-Open No. 1-1301.
No. 59 is proposed.

In the method of cleaning a support containing water as a main component, in order to increase the cleanliness of the support, an auxiliary agent such as a surfactant is used in combination, a cavitation effect by ultrasonic oscillation or a jet nozzle is used. High pressure injection,
It is known that it is effective to use a brush or a blade in combination.

[0009]

However, when the substrate is washed with water, a non-uniform oxide film may be formed on the surface of the support or irregularities may be formed on the surface of the support. In some cases, the characteristics of the electrophotographic photosensitive member were affected.

In particular, with recent demands for higher image quality, higher speed, and higher durability, an electrophotographic photosensitive member having more excellent characteristics has been studied.

Accordingly, an object of the present invention is to provide an electrophotographic photosensitive member having excellent electrophotographic characteristics.

It is another object of the present invention to provide a method for producing an electrophotographic photosensitive member capable of providing an electrophotographic photosensitive member having excellent characteristics without adversely affecting the environment or the human body.

[0013]

That is, the present invention relates to an electrophotographic photoreceptor having a conductive support, an intermediate layer and a photosensitive layer in this order, wherein the surface of the conductive support contains water as a main component. And the intermediate layer is a metal,
An electrophotographic photoreceptor containing a conductive material and a resin selected from the group consisting of metal oxides and carbon black, and having a second intermediate layer between the intermediate layer and the photosensitive layer.

Further, the present invention provides a step of washing the surface of a conductive support with a solution containing water as a main component, wherein the conductive support selected from the group consisting of metals, metal oxides and carbon black is provided on the washed support surface. Forming an intermediate layer containing an active substance, forming a second intermediate layer on the intermediate layer, and forming a photosensitive layer on the second intermediate layer. This is a method for manufacturing a photoconductor.

Examples of the conductive support used in the present invention include metals such as aluminum, copper, iron, brass and stainless steel, alloys to which these metals or other elements are added, and metals and alloys of these metals, such as paper and plastic. And those coated or deposited on ceramics and the like.
Among these, aluminum or an aluminum alloy is preferable from the viewpoint of workability and dimensional stability. The shape of the conductive support is not particularly limited, such as a drum shape and a sheet shape. In the present invention, the surface of the conductive support may or may not be processed by cutting or the like.

In the present invention, the solution containing water as a main component used for washing the support may contain only water, or may further contain an auxiliary agent such as a weak acid to weak alkali surfactant. May be. In the present invention, a solution containing 0.1 to 20 parts by weight of a surfactant per 100 parts by weight of water is preferable. The water used has a specific resistance of 0.1 MΩc
It is preferably high-purity water of m or more.

The surfactant is a compound composed of a hydrophobic group and a hydrophilic group. This compound has a property that it is easily collected at the interface between two substances (substrate and oil), and it is difficult to separate the two substances. effective. This compound is roughly classified into two types, an ionic type and a non-ionic type, depending on the type of the hydrophilic group. Examples of the ionic system include sodium salt of a higher aliphatic alcohol sulfate, alkyltrimethylammonium chloride, and alkyldimethylbetaine. Examples of the ionic system include an aliphatic higher alcohol ethylene oxide adduct (polyethylene glycol alkyl ether) and the like, all of which effectively act on the present invention.

The washing temperature varies depending on the surfactant used, but is preferably 25 to 80 ° C.

For more effective cleaning, the support is not merely immersed in a water bath, but also by using a brush or a blade, spraying water at a high pressure with a jet nozzle or the like, or using ultrasonic waves. Although it can be used, among them, the method of applying ultrasonic waves is most preferable.

In the present invention, the washing is not limited to one step, but may be a plurality of steps such as pre-washing, main washing, post-washing and rinsing.

In the present invention, in order to further increase the cleanliness, it is preferable to carry out steam treatment with pure water after washing, immersion and pulling up in a hot pure water bath, and hot air drying after pure water shower treatment. Of these, immersion in a hot pure water bath and lifting are particularly preferred. The conductivity of the pure water used is preferably 5 μS or less, and especially 1 μS.
It is preferably at most μS. The processing temperature is 25
The temperature is preferably from 90 ° C. to 90 ° C., particularly 40 ° C.
It is preferable that the temperature is not less than 80 ° C.

By these treatments, an oxide film is formed on the surface of the conductive support. The oxide film not only has a property that hole injection from the support is good, but also has good adhesion to a layer provided on the support.

However, the oxide film may be formed non-uniformly, or the surface of the support may be uneven. Therefore, in the present invention, by providing a layer containing a conductive substance between the photosensitive layer and the photosensitive layer. Thus, an electrophotographic photosensitive member having more excellent electrophotographic characteristics could be obtained.

The conductive substance used in the present invention includes:
Examples include metal oxides such as tin oxide, indium oxide, zinc oxide, aluminum oxide, antimony oxide, titanium oxide, iron oxide, barium sulfate, and barium carbonate; and metals such as carbon black, aluminum, silver, copper, and nickel. Of these, metal oxides are preferred.
The conductive substance may be used alone or as a mixture of two or more kinds. When two or more types are mixed, not only each of them may be used at the same time, but also a solid solution or a fused one may be used. The layer containing a conductive substance further contains a resin. As the resin material used, polyvinyl alcohol, gelatin, casein, rosin, cellulose,
Polyamide, polyacrylic acid, polyacrylate, polymaleic acid, polyacrylate, polystyrene, polyethylene, polyvinyl chloride, polyvinyl acetate, polyvinylpyrrolidone, polyester, polycarbonate, polystyrene-maleic acid copolymer, polystyrene-methyl acrylate copolymer, etc. Thermoplastic resins, and epoxy resins, urethane resins, unsaturated polyester resins, alkyd resins, acrylic-melamine resins, silicone resins,
Thermosetting resins such as curable rubbers and phenolic resins are exemplified. A thermosetting resin is preferred in consideration of the ease of elution when the photosensitive layer is further laminated on the intermediate layer. In particular, a phenol resin obtained by reacting phenols with aldehydes in the presence of an alkali catalyst to form a resole and curing the formed resole with heat or an acid is preferable.

As phenols used for producing resole, m-cresol, o-cresol, p-cresol, 3.5-xylenol, 2.5-xylenol, 2.4 xylenol, phenol and the like are used. As the aldehyde, formaldehyde, furfural or acetaldehyde is used. Especially,
In the present invention, the reaction product of phenol and formaldehyde is preferred.

The alkali catalyst used in the reaction includes alkali metal hydroxides such as sodium hydroxide, lithium hydroxide and potassium hydroxide, dimethylamine, and the like.
Ethylamine, methylamine, getylamine, di-n
Primary amine such as -propylamine, i-propylamine, n-propylamine, hexamethylenetetramine, pyridine, dibenzylamine, trimethylamine, benzylamine, triethylamine, secondary amine or tertiary amine, or ammonia Can be used.

As such a resol, "Plyofen J-325" and "Plyofen 5010" manufactured by Dainippon Ink and Chemicals, Inc. are known. The weight average molecular weight of the phenolic resin obtained by curing such a resol under predetermined curing conditions is 350 to 2
0000 is preferred.

The ratio between the resin and the conductive substance is 1: 1:
It is preferably 5 to 1: 1. Examples of the method of mixing and dispersing these include a roll mill method, a ball mill method, a vibration ball mill method, an attritor method, a sand mill method, and a colloid mill method. The thickness of the intermediate layer is
It is preferably 1 to 30 μm, particularly 5 to 25 μm.
m is preferable.

In the present invention, from the viewpoints of further preventing the photosensitive layer from seeping into the intermediate layer, further improving the adhesion between the photosensitive layer and the intermediate layer, and further stabilizing the electrophotographic characteristics, A second intermediate layer is provided on the intermediate layer.

As the resin used for the second intermediate layer,
Polyvinyl, alcohol, polyvinyl methyl ether,
Water-soluble resins such as polyvinylpyridine, polyacrylic acids, methylcellulose, ethylcellulose, polyglutamic acid, casein, gelatin and starch, polyamide resins, phenolic resins, polyvinylformal, polyurethane elastomers, alkyd resins, ethylene-vinyl acetate copolymers and vinylpyrrolidone-acetic acid Resins such as vinyl copolymers are included.

Of these, polyamide resins are preferred. The thickness of the second intermediate layer is preferably from 0.1 to 5 μm, particularly preferably from 0.3 to 2 μm.

The photosensitive layer used in the present invention may be a single-layer type photosensitive layer containing a charge generating material and a charge transporting material in the same layer, or a charge generating layer containing a charge generating material, and a charge transporting material. And a laminated photosensitive layer in which a charge transport layer is contained.

Examples of the charge generating material include organic photoconductors such as pyrylium, thiopyrylium dyes, phthalocyanine pigments, anthantrone pigments, perylene pigments, dibenzopyrenequinone pigments, pyranthrone pigments, azo pigments, indigo pigments and quinacridone pigments. Is used.

As the charge transport material, organic photoconductors such as pyrazoline-based, hydrazone-based, stilbene-based, triphenylamine-based, benzidine-based, oxazole-based and indole-based, and carbazole-based compounds are used.

The single-layer type photosensitive layer is formed by dispersing and dissolving the above-mentioned charge generating material and charge transporting material in a suitable binder resin, coating and drying. The film thickness is preferably from 5 to 40 μm, and particularly preferably from 10 to 30 μm.

As the laminated photosensitive layer, there is a layer in which a charge generation layer and a charge transport layer are laminated in this order, or 2) a layer in which a charge transport layer and a charge generation layer are laminated in this order. As a method for forming the charge generation layer, a method in which a liquid in which the above-described charge generation material is dispersed in an appropriate binder resin and a solvent is applied and dried. The thickness of the charge generation layer is preferably 5 μm or less, particularly preferably 0.01 to 3 μm.

The charge transport layer is formed by applying a liquid obtained by dissolving the above-described charge transport material in a binder resin having a film-forming property and drying the solution. The film thickness is 5 to 40 μm, especially 8 to
35 μm is preferred.

When a charge generation layer is laminated on the charge transport layer, both layers can be formed by applying and drying the above-mentioned organic photoconductor together with a binder resin. At this time, it is preferable to include a charge transport material also in the charge generation layer.

Examples of the method for applying the above-mentioned various layers include a dip coating method, a spray coating method, a beam coating method, a roller coating method, a Meyer bar coating method and a blade coating method.

The electrophotographic photoreceptor of the present invention can be used for a laser beam printer, an LED printer,
The present invention can be applied to photoreceptors of various devices to which an electrophotographic method is applied, such as an LCD printer, a CRT printer, and a facsimile.

[0041]

【Example】

1. Non-cutting aluminum cylinder (30mmφ × 26
0 mmL x 1 mm thick). This aluminum cylinder was immersed in a 1% by weight aqueous solution of a cleaning agent (Banrise D-20, Tokiwa Chemical Co., Ltd.), and an ultrasonic oscillator (600
(W, 40 KHz) for 1 minute. After rinsing the cylinder with pure water, the cylinder was immersed in pure water at 80 ° C. and a conductivity of 0.5 μS for 1 minute, then pulled up and dried.

The work function (Wf) of the cylinder surface was measured with a surface analyzer (AC-1 Riken Keiki Co., Ltd.).
It was 4.5 eV.

Next, 50 parts (parts by weight, the same applies hereinafter) of tin oxide powder and rutile type titanium oxide powder, and 40 parts of resole (trade name: Plyofen J-325, manufactured by Dainippon Ink Co., Ltd.) , Methyl alcohol and 30 parts of 2-methoxyethyl alcohol were mixed and dispersed in a ball mill for 5 hours.

The obtained paint was dip-coated on the previously washed aluminum cylinder, and dried and cured at 150 ° C. for 30 minutes. The film thickness was 20 μ.

Next, 5 parts of methoxymethylated 6-nylon (Tresin, Teikoku Chemical) is dissolved in 50 parts of methanol and 45 parts of butanol, and then dipped and applied to form a 0.2 μm thick second intermediate layer. Was provided.

Next, 10 parts of a disazo pigment having the following structural formula was added.

[0047]

[Outside 1] Six parts of cellulose acetate butyrate resin (trade name: CAB-381, manufactured by Eastman Chemical Co.) and 60 parts of cyclohexanone were dispersed in a sand mill using 1φ glass beads for 20 hours. To this dispersion, 100 parts of methyl ethyl ketone was added, and dip-coated on the intermediate layer.
After drying for a minute, a charge generation layer was formed.

Next, 10 parts of a hydrazone compound of the following structural formula

[0049]

[Outside 2] And 12 parts of a styrene-methyl methacrylate copolymer resin (trade name: MS-200, manufactured by Iron and Steel Chemical Co., Ltd.) are dissolved in 70 parts of toluene, coated on the charge generation layer, and dried at 100 ° C. for 60 minutes. As a result, a charge transport layer having a thickness of 16 μm was formed.

The electrophotographic photoreceptor thus manufactured is mounted on a copying machine FC-3 manufactured by Canon Inc., and the three environments of high temperature and high humidity; normal temperature and normal humidity; and low temperature and low humidity, that is, the temperature / humidity is 32 ° C / 85%, 22 ° C / 50% and 15 ° C / 10%
Copying was performed in the three environments described above, and good images were obtained in each case.
The dark area potential (V _D ) of the photoreceptor was measured under each environment under the conditions that the standard drum around which a 25 μm thick polyester film was wound was charged to −700 V.
Next, the dark portion potential of each photosensitive member was reset so as to be -600 V, and the amount of light necessary for the bright portion potential ( _VL ) to be -200 V was measured as sensitivity. Furthermore, to measure the pre-exposure immediately after potential as the residual potential (V _R).

Table 1 shows the results.

(Comparative Example 1) The same as Example 1 except that the aluminum cylinder was washed / dried using trichloroethane without using an aqueous solution and pure water, and further provided with no layer containing a conductive substance. Table 1 shows the evaluation results.

(Comparative Example 2) A photoconductor was prepared and evaluated in the same manner as in Example 1, except that a layer containing conductive particles was not provided. Table 1 shows the results.

[0054]

[Table 1]

2. The aluminum cylinder (30 mmφ × 346 mmL × 1 mm thick) after the cutting process was used in Example 1.
Washed, rinsed and treated with pure water as described above.

As the conductive powder, a rutile-type titanium oxide powder (coating amount: 75% by weight of titanium oxide) whose surface was coated with tin oxide and antimony oxide (10% by weight of tin oxide) was prepared. Was mixed with 5 parts of resole (trade name: Plyofene 5010, manufactured by Dainippon Ink and Chemicals, Inc.), 8 parts of ethyl alcohol and 6 parts of 2-ethoxyethyl alcohol, and then dispersed in a ball mill for 6 hours.

The paint was applied on the washed aluminum cylinder and dried at 150 ° C. for 30 minutes to be cured. Thus, an intermediate layer of the present invention having a thickness of 20 μm was provided. Further, a second intermediate layer similar to that shown in Example 1 was provided.

Next, as a charge generation material, a structural formula

[0059]

[Outside 3] Was dispersed in a sand mill using glass beads using 10 parts of Disazo Facial Family, 6 parts of polyvinyl butyral resin (Eslek BX-1, manufactured by Sekisui Chemical) and 50 parts of cyclohexanone. To this dispersion, 100 parts of tetrahydrofuran was added, dip-coated on the above-mentioned intermediate layer, and dried to form a charge generation layer.

Next, the structural formula

[0061]

[Outside 4] A solution obtained by dissolving 10 parts of a stilbene compound represented by the following formula and 10 parts of a polycarbonate resin (Panlite L-1250, manufactured by Teijin Chemicals) in 50 parts of dichloromethane and 10 parts of monochlorobenzene is applied by dip coating on the charge generation layer to 25 μm.
A thick charge transport layer was formed.

The obtained photoreceptor was copied to a copying machine NP-2020.
The evaluation was performed in the same manner as in Example 1, except that

Table 2 shows the results.

(Comparative Example 3) A photoreceptor was prepared in the same manner as in Example 2, except that the aluminum cylinder was washed / dried using trichloroethane without using an aqueous solution and pure water, and the resin layer of the present invention was not provided. did.

Comparative Example 4 A photoconductor was prepared and evaluated in the same manner as in Example 2, except that the layer containing a conductive substance was not provided.

Table 2 shows the results.

[0067]

[Table 2]

Comparative Example 5 Aluminum cylinder after cutting (80 mmφ × 3)
(60 mmL x 1 mm thick). The above-described aluminum cylinder was immersed in a trichloroethane solution, and washed for 1 minute using an ultrasonic oscillator (600 W, 40 KHz).

[0069]

[0070]

On the cleaned aluminum cylinder, the same charge generation layer and charge transport layer as in Example 1 were sequentially laminated. This photoreceptor is used with a copier NP-37 manufactured by Canon Inc.
The evaluation was performed in the same manner as in Example 1 except that the device was set to 25.

Table 3 shows the results.

[0073]

[0074]

Comparative Example 6 A photoconductor was prepared and evaluated in the same manner as in Comparative Example 5, except that the aluminum cylinder was washed as described below.
Aluminum cylinder after cutting (80mmφ × 360m
mL x 1 mm thick). The above-described aluminum cylinder was immersed in a 5% by weight aqueous solution of a cleaning agent (Power Challenger, Neos Co., Ltd.), and an ultrasonic oscillator (600
(W, 40 KHz) for 1 minute. Next, after rinsing with pure water, it was immersed (3 minutes) in pure water of 80 ° C. and electric conductivity of 0.1 μS, sufficiently heated, pulled up and dried. When the work function of the cylinder surface was measured in the same manner as in Example 1, it was 5.1 eV.

Table 3 shows the results.

[0077]

[Table 3]

[0078]

As described above, according to the present invention, it is possible to provide an electrophotographic photosensitive member exhibiting good electrophotographic characteristics in all environments without affecting the environment or the human body.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kyoichi Sawada 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Mutsugu Otaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Hideaki Maruoka 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-5-158268 (JP, A)

Claims (8)

(57) [Claims] 1. An electrophotographic photoreceptor having a conductive support, an intermediate layer and a photosensitive layer in this order, wherein the surface of the conductive support is washed with a solution containing water as a main component,
And the intermediate layer contains a metal, a conductive material and a resin selected from the group consisting of metal oxides and carbon black,
An electrophotographic photoreceptor comprising a second intermediate layer between the intermediate layer and the photosensitive layer. 2. The method according to claim 1, wherein the conductive material is a metal oxide.
The electrophotographic photosensitive member according to the above. 3. The electrophotographic photoreceptor according to claim 1, wherein the resin is a thermosetting resin. 4. A step of washing the surface of the conductive support with a solution containing water as a main component, a conductive substance selected from the group consisting of metal, metal oxide and carbon black on the washed support surface; Forming an intermediate layer containing a resin, forming a second intermediate layer on the intermediate layer, and forming a photosensitive layer on the second intermediate layer. How to make the body. 5. The conductive material is a metal oxide.
The method for producing the electrophotographic photosensitive member according to the above. 6. The method according to claim 4, wherein the washing is performed a plurality of times. 7. The method for producing an electrophotographic photoreceptor according to claim 6, wherein ultrasonic waves are applied to the solution during at least one of a plurality of washings. 8. The method for producing an electrophotographic photoreceptor according to claim 4, wherein the surface of the conductive support is immersed in warm pure water after washing, and then raised.