JP2932679B2 - Method for producing organic photoreceptor having surface protective layer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing an organic photoconductor having a vacuum thin film as a surface protective layer.

2. Related Art and Problems In recent years, electrophotographic photoconductors in which an organic photoconductive material is blended with an adhesive resin have been widely used.

This type of photoreceptor has no hygiene problems and is excellent in processability, and has excellent industrial productivity in comparison with photoreceptors using selenium or cadmium sulfide.

However, these organic photoconductors have poor hardness, and are liable to be scratched and damaged by friction with transfer paper, a cleaning member, a developer and the like in repeated use.

In order to solve such a problem, there is a technique of providing a surface protective layer on the surface of the organic photosensitive layer.

As one kind of such a surface protective layer, a vacuum thin film of an appropriate compound has been proposed.

It is also possible to form a vacuum thin film having a high hardness, and an organic photoreceptor having such a vacuum thin film as a surface protective layer of an organic photosensitive layer is an organic photoreceptor having no surface protective layer. In comparison, it has excellent durability and has sufficient film strength for long-term use under normal temperature and normal humidity, but its moisture resistance after long-term use cannot be said to be sufficient. A problem arises in that the potential rises and black streak-like image noise occurs.

On the other hand, it is ideally desirable to form the surface protective layer on the surface immediately after the formation of the organic photosensitive layer. In general, a large amount of the layer only is manufactured at a time, and then subjected to a step of forming a surface protective layer such as an amorphous carbon film. During that time, the organic photosensitive layer is often stored for several days to about one month (the storage period is often referred to as “the initial period”).

After formation, the surface of the organic photosensitive layer is oxidized by oxygen in the air over time. If a vacuum thin film, for example, an amorphous hydrocarbon film is to be provided on the surface of the organic photosensitive layer having such an oxide film formed thereon, the adhesion between the oxide film surface and the vacuum thin film is poor, so that the surface protective layer is not provided. Peeling occurs. According to the experience of the present inventors, this phenomenon is likely to occur in an organic photosensitive layer one day after coating.

Problem to be Solved by the Invention The present invention has been made in view of the above circumstances, and before forming a vacuum thin film as a surface protective layer on the surface of an organic photosensitive layer, cleaning and roughening the surface of the photosensitive layer are performed. This is intended to solve the above problem.

That is, an object of the present invention is to provide a method for producing an organic photoreceptor free of surface peeling, increase in residual potential, and generation of black stripes.

Means for Solving the Problems The present invention comprises a step of washing the organic photosensitive layer with a solvent having an action of removing an oxide film on the surface of the organic photosensitive layer, and a step of roughening the surface of the organic photosensitive layer. And forming a vacuum thin film as a surface protective layer after passing through the process.

The method for producing a photoreceptor of the present invention comprises a step of first cleaning an organic photosensitive layer and a step of roughening the surface.

The photosensitive layer is a known organic photosensitive layer provided on a conductive substrate, and the internal structure of the photosensitive layer is obtained by mixing a photoconductive material and a charge transport material on a conductive substrate with a binder. A photosensitive layer having a single-layer structure, a photosensitive layer having a function-separated structure in which a charge generation layer and a charge transport layer are sequentially formed on a conductive support, or a charge transport layer and a charge generation layer on a conductive support. Any of the function-separated configurations formed sequentially may be used. However, as the charge generation layer, there is also a layer formed of only the charge generation substance itself without using a binder resin, such as a phthalocyanine vapor-deposited film. The present invention is effective if a resin dispersion type charge transport layer is provided.

When a surface protective layer is provided, the photosensitive layer below the protective layer may be bombarded by electrons or ions in plasma,
There has been proposed a photoreceptor having a structure in which a resin layer is temporarily provided on the photosensitive layer so as not to be deteriorated by heat or the like (see, for example,
In the case of a photoconductor having such a configuration,
Regardless of the type of the photosensitive layer, whether inorganic or organic, the application of the present invention improves the durability and the decrease in sensitivity to increase in residual potential (black streaks).

Washing of the organic photosensitive layer is not particularly limited as long as it has an action of removing an oxide film on the surface of the photosensitive layer. Specifically, examples of the solvent that can be used for washing the organic photosensitive layer include n-hexane, cyclohexane, pentane, cyclopentane, heptane, octane, ligroin, petroleum ether, benzene, isohexane, neohexane, 1-Hensen, and the like. Saturated hydrocarbons, methanol,
Ethanol, propanol, butyl alcohol, allyl alcohol, hydrocarbon alcohols such as benzyl alcohol, toluene, xylene, hemimelitene, pseudo cumene, aromatic hydrocarbons such as tetralin, acetone,
Ketones such as ethyl methyl ketone, cyclohexanone and methyl vinyl ketone, and ethers such as ethyl ether and methyl ether can be mentioned. Preferred are n-hexane and isohexane.

In addition, solvents containing halogen atoms can be used.
The hydrogen atom bonded to the carbon atom of the hydrocarbon alcohol of No. 6 is substituted with a fluorine atom, and any isomer can be applied.

Such fluorinated alcohols include methanol fluoride,
Ethanol fluoride, propanol fluoride, butanol fluoride, pentanol fluoride, hexanol fluoride, butanediol fluoride and the like can be mentioned. Preferred fluorinated alcohols are 5-fluorinated propanol, 3-fluorinated propanol and the like, most preferred is 5-fluorinated propanol (including all isomers).

Besides, 1,1,2-trichloro-1,2,2-trifluoroethane and the like are also applicable.

As a method for cleaning the photosensitive layer, a dipping method, a shower method, a steam cleaning method, or the like may be applied. May be selected and set as appropriate depending on the type of the device.

A dipping method is preferred. In this washing method, for example,
It is sufficient to immerse the photosensitive layer in a hexane solvent at 20 ° C. for about 60 seconds. In order to enhance the washing effect, ultrasonic vibration may be applied, or the solvent may be circulated (purified).

On the surface of the photoconductor thus cleaned, for example, a plasma CVD method, a photo CVD method, a thermal CVD method, a sputtering method,
The surface protective layer (vacuum thin film) can be formed with good adhesiveness by various methods such as a vapor deposition method and an ion plating method.

The method of surface roughening is not particularly limited. For example, natural fibers (animal hair such as wool, deer, rabbit hair,
Cotton, hemp, etc.), chemical fibers (rayon, acetate, nylon, polypropylene, acrylic, polyester, Teflon, etc.), glass fibers or stainless steel fibers, etc., are three-dimensionally entangled by the action of moisture, heat, and pressure to form a sheet. And mechanical polishing means (buff polishing, brush polishing, etc.) for pressing and sliding a cloth made of the above-mentioned felt, a cloth made of these fibers, and a brush.

When such a mechanical polishing means is used, an abrasive (particles made of a resin or an inorganic substance) may or may not be present together with water, a surfactant, a cutting oil and the like. When an abrasive is used, a felt, a cloth, or a brush in which abrasive particles are embedded or bonded may be used.

The surface roughness is determined by the type, size, thickness or density of the fiber, or, if abrasive particles are used, the type, size, thickness or density of the abrasive particles, as well as the pressing force and rubbing force of the polishing machine. Can be controlled by

For example, wool felt inner buff (20cm in diameter)
When the surface is roughened by polishing a resin-dispersed photosensitive drum with a diameter of 80 mm and a length of 330 mm, pure spouting liquid: 1 / min Drum rotation speed: 100 to 240 rpm Buff rotation speed: 50 to 850 rpm Buff feed: 0.3 to 1 cm Buff center deviation: 4.5 to 6 cm Buff load: Under polishing conditions of 2.5 to 15 kg, surface roughness suitable for the present invention can be obtained. Of course, the above conditions are illustrative, and do not limit the conditions for achieving the surface roughness of the present invention at all.

When buffing is performed, the processing may be performed using a plurality of buffs as shown in FIG. 1 or FIG. As shown in FIG. 3, the drum may be set in the state of a drain line and buffing may be performed. Further, as shown in FIG. 4, the polishing treatment may be performed in a state where the buff is put on one side.

As still another method, a sand blast method in which abrasive particles are hit on the surface of the photosensitive layer can be used. Further, the surface of the photosensitive layer can be finely roughened by forming the organic photosensitive layer by applying a coating solution to which powder particles such as silica are added in advance.

The degree of surface roughening is expressed as a maximum height (Rt) of 0.
05 μm to 0.4 μm, preferably 0.08 to 0.24 μm,
It is expressed as the average mountain interval (Sm) between rough peaks and 100
The surface is roughened so as to be not more than μm, preferably not more than 80 μm.

Maximum height is less than 0.05μm, average peak interval is 100μ
m, image noise such as black stripes, and poor adhesion of the surface protective layer. If the maximum height is larger than 0.4 μm and the average peak interval is larger than 100 μm, problems such as film defects and toner filming will occur.

When a surface protective layer of a vacuum thin film is formed on the surface of the photosensitive layer subjected to the surface roughening treatment according to the present invention, the vacuum thin film includes a film stress, and countless cracks enter the film in the thickness direction. As a result, it is considered that countless spots are isolated in the form of islands on the surface of the photosensitive layer, thereby preventing the horizontal flow of charges and the increase in residual potential, and the problem of black streak formation is eliminated.

In the present invention, the maximum height (Rt) and the average peak interval (Sm) refer to those described in JIS BO601-1982.
2.5mm is used as the standard length in the JIS.

The order of performing the cleaning step and the roughening step may be any of the order of the cleaning step → the roughening step or the order of the roughening step → the cleaning step. A preferred order is a washing step → a roughening step.

When a roughening step is performed after the cleaning step, the oxide film on the surface of the photosensitive layer is removed by the cleaning processing. No oxide film is formed by the subsequent roughening treatment. Therefore, the adhesiveness of the vacuum thin film as the surface protective layer to the photosensitive layer is ensured. In addition, the shape of the photosensitive layer surface is not affected by the cleaning treatment, and is determined by the subsequent roughening treatment, so that the surface shape of the photosensitive layer can be easily controlled.

The surface roughening process is performed as soon as possible after the completion of the cleaning process.
Otherwise, an oxide film is formed again on the surface, and the effect of the cleaning treatment is lost.

On the other hand, when the cleaning step is performed after performing the reverse order, that is, performing the roughening step, the oxide film on the surface of the photosensitive layer is removed by the subsequent cleaning processing, so that the adhesion of the vacuum thin film to the photosensitive layer is poor. No problem arises. However, although the roughened surface is not smoothed by the subsequent cleaning treatment, the surface tends to be roughened. This is because the surface area of the photosensitive layer is increased by the surface roughening treatment, and the amount of the photosensitive layer component eluted by the washing treatment is smaller than that in the case where the surface is not roughened.
I think this is because it has increased significantly. Therefore, in this processing sequence, it is difficult to control the surface roughness, and wiping is likely to occur during toner cleaning.

After the completion of the washing step and the surface roughening treatment, a vacuum thin film is formed on the surface of the organic photosensitive layer to form a surface protective layer. As such a surface protective layer, amorphous hydrocarbons formed by a plasma polymerization method, or Al ₂ O ₃ , Bi ₂ O ₃ , Ce ₂ O ₃ , Cr ₂ O ₃ ,
In ₂ O ₃ , MgO, SiO, SiO ₂ , SnO ₂ , Ta ₂ O ₃ , TiO, TiO ₂ , ZrO
_2, Y metal oxides such as _{2 O 3, Si 3 N 4} , a metal nitride such as _{Ta 2 N, MgF 2, LiF} , NdF 3, LaF 3, C 3 F 2, CeF 3 metal fluorides such as, Metal compounds such as metal carbides such as SiC and TiC, and metal sulfides such as ZnS, CdS, and PbS are formed using a so-called vacuum thin film forming technique such as an evaporation method, a sputtering method, or an ion plating method. Can be

The thickness of the surface protective layer is 0.01 to 5 μm, preferably 0.04 to 1 μm, assuming that it is formed on a mirror-like surface without fine irregularities. With such a film thickness,
The unevenness on the surface of the photosensitive layer appears almost as it is on the surface protective layer. If the thickness is more than 5 μm, cracks, which are considered to be based on internal stress, are not formed in the formed vacuum thin film, and the above-mentioned problem still remains. The film thickness is 0.
When the thickness is less than 01 μm, the plate is easily worn or peeled off during printing.

 Hereinafter, the present invention will be described with reference to Examples.

Preparation of Organic Photosensitive Layer (a) (Negative Band Electricity Separation Type) 1 part by weight of bisazo pigment chlorodia blue (CDB), 1 part by weight of polyester resin (manufactured by Toyobo Co., Ltd .: V-200), and 100 parts by weight of synchrohexanone Of the mixture was dispersed with a sand grinder for 13 hours. This dispersion is 80 mm in diameter
It was applied by dipping on a cylindrical aluminum substrate having a length of 330 mm and dried to form a charge generation layer having a thickness of 0.3 μm.

Separately, 1 part by weight of 4-diethylaminobenzaldehyde-diphenylhydrazone (DEH) and 1 part by weight of polycarbonate (manufactured by Teijin Chemicals Limited; K-1300) are dissolved in 6 parts by weight of tetrahydrofuran (THF). The resultant was coated and dried, and a charge transport layer having a thickness of 15 μm after drying was formed to obtain an organic photosensitive layer (a).

Preparation of organic photosensitive layer (b) (binder type for positive charging) 25 parts by weight of special α-type copper phthalocyanine (manufactured by Toyo Ink Co., Ltd.), acrylic melamine heat effect resin (manufactured by Dainippon Ink Co., Ltd .: A-405 and super A mixture of 50 parts by weight of becamine J820), 25 parts by weight of 4-diethylaminobenzaldehyde-diphenylhydrazone and 500 parts by weight of an organic solvent (a mixture of 7 parts by weight of xylene and 3 parts by weight of butanol) was pulverized and dispersed in a ball mill for 10 hours. . Disperse the dispersion to a diameter of 80
It was applied on a cylindrical aluminum substrate having a size of mm × 330 mm by dipping and dried and baked (at 150 ° C. for 1 hour) to obtain an organic photosensitive layer (b) having a thickness of 15 μm.

Example 1 (Washing of photosensitive layer) (abbreviated as W1) The organic photosensitive layer (a) was stored in an environment of 20 ° C. and 65% for 30 days. The cleaning was performed using the cleaning apparatus shown in FIG.

In FIG. 5, (1) is a photosensitive drum (1) having a photosensitive layer (a) provided on a substrate, which is attached to a vertically movable shaft (2) by means (3) having a hydraulic vertical mechanism. I have. (4) is a washing tank having an internal volume of 30 (length) × 30 (width) × 50 (height to liquid level) cm ³ , and is filled with a cleaning solvent (5). . The solvent (5) is circulated and used in the distillation circulator (6).

The cleaning was performed by gradually lowering the photosensitive drum (1) by the hydraulic vertical means (3) and dipping the photosensitive drum (1) entirely in a container in the cleaning tank (4). At this time, in order to perform cleaning more effectively, the ultrasonic oscillator (7)
, Was appropriately subjected to ultrasonic cleaning.

The amount of the solvent used for the actual cleaning was about 50 including the distillation circulator (6) and the piping. The liquid temperature was set to 20 ° C. by a temperature controller (not shown). The output of the ultrasonic oscillator used appropriately is 50
W.

In the above cleaning process, n-hexane was used as a solvent, immersion operation 30 seconds, immersion time 10 seconds,
The cleaning was performed with a difference of 60 seconds between the drum surface cleaning time (shortest 10 seconds and maximum 70 seconds).

The immersion operation, immersion time, lifting operation, and drum surface cleaning time difference are described below.

Immersion operation: The time from when the lower end of the photosensitive drum touches the liquid surface to when the upper end is immersed in the liquid surface while lowering the shaft at a constant speed.

In other words, for a drum with a length of 330 mm,
[Second] means that the shaft was lowered at 330/30 = 11 mm / sec.

Immersion time: The time during which the entire photosensitive drum is immersed below the liquid level.

-Pulling operation: The time from when the upper end of the photosensitive drum comes out above the liquid surface to when the lower end comes out, at the time of lifting, as opposed to the dipping operation.

The difference between the immersion time in the liquid at the lower end of the drum and that at the upper end of the drum was determined as the drum surface cleaning time difference by measuring the shortest time and the longest time as follows.

・ Minimum time: The time during which the upper end of the drum is immersed below the liquid level. That is, it is equal to the immersion time.

・ Longest time: The time when the lower end of the drum is immersed below the liquid level. That is, it is equal to the immersion operation + the immersion time + the lifting operation.

(Surface roughening treatment) (abbreviated as R1) The surface of the organic photosensitive layer (a) washed above was finely polished by a buff polisher shown in FIG.

The organic photosensitive layer is fixed by chucking (301),
A buff made from wool into a 3cm-thick disc (density 0.03g / c
m ³ ) (buff diameter: 20 cm) (303) was set at a position of 4.5 cm buffing. The buff shift is the distance between the center line in the longitudinal direction of the photoconductor (304) and the center point of the disk-shaped buff (303) as shown in FIG.

Next, the photosensitive layer (304) is rotated at 300 rpm in the direction of the arrow (d) (this rotation is referred to as work rotation), and the disk-shaped buff (30) is rotated.
While rotating 3) at 500 rpm in the direction of arrow (c), apply a load of 6.6 kg to the disk-shaped buff (303) from the direction of arrow (a) (this load is referred to as buff load), and remove the disk-shaped buff (303). Pressure was applied to the photosensitive layer (304). At this time, the loose wire load on the photosensitive layer (304) was 0.3 kg / cm. In this state, the buff (303) reciprocated three times in the direction of arrow (b) at a feed rate of 1 cm / sec. At the same time, the photosensitive layer (304)
Discharge nozzle (3) toward the contact surface between the
02) Purer was discharged at a rate of 1 / min.

The surface of the organic photosensitive layer (a) had a roughness of 0.086 μm as represented by the maximum height (Rt).

In addition, Rz was measured according to JIS-BO601-1982. The measuring machine used was a surface roughness meter Surfcom 550A (trade name) manufactured by Tokyo Seimitsu Co., Ltd.

Next, a plasma amorphous hydrocarbon film (hereinafter abbreviated as PAC) was formed on the surface of the organic photosensitive layer as follows.

(Preparation of PAC) In the glow discharge decomposition apparatus shown in FIG. 8, first, the inside of the reactor (733) is evacuated to a high vacuum of about 10 ^-4 Torr, and then the first and second control valves (707 and 708) Release
Hydrogen gas from the first tank (701) and butadiene gas from the second tank (702) flow into the first and second flow controllers (713 and 714) at an output pressure of 1.0 kg / cm ² , respectively. Was. Then, the scale of each flow controller is adjusted, and the flow rate of hydrogen gas is set to 300 sccm, and the flow rate of butadiene gas is set to 30 scom, and the reaction is performed from the main pipe (732) via the intermediate mixer (731). Flowed into room (733). After each flow rate was stabilized, the pressure regulating valve (745) was adjusted such that the pressure in the reaction chamber (733) became 0.5 Torr. On the other hand, the substrate (75
As 2), the above-mentioned organic photosensitive layer (a) was previously heated to 50 ° C., and was previously connected by the connection selection switch (744) while the gas flow rate and pressure were stable. The low-frequency power supply (741) is turned on and the power application electrode (73
6) Apply 180Watt power under the frequency of 100KHz to about 18
A plasma polymerization reaction was performed for 0 second to form a 1200-mm-thick amorphous carbon film (PAC film) as a surface protective layer on the substrate (752). After the film formation was completed, the application of power was stopped, the control valve was closed, and the inside of the reaction chamber (733) was sufficiently evacuated. Then, the vacuum was broken and the photoconductor of the present invention was taken out.

(Evaluation) The photoreceptor obtained as described above was evaluated for adhesiveness, reduced sensitivity and unwiped residue.

Adhesion evaluation A JIS-K5400 standard cross-cut test was performed to evaluate the adhesion of the surface protective layer to the organic photoreceptor, and ranking was performed as in the chemical formula.

Evaluation of sensitivity reduction Mount the prototype photoconductor on the actual machine, adjust the exposure amount,
A halftone image with an image density of 0.50 was obtained.

Thereafter, after making 10,000 copies of A4 paper, a halftone image was obtained with the same exposure, the image density was obtained, and the difference from the initial image density of 0.50 was obtained.

For example, if the image density after copying 10,000 sheets is 0.55, the difference 0.05 is regarded as the sensitivity reduction.

The surface potential of the actual machine was set at 400 [V], and the developing bias was set at 150 [V].

In the list of examples, the quality of sensitivity reduction was shown based on the following evaluation criteria.

The image density was measured using a thermometer and Sakura Densitometer DA65 (trade name) manufactured by Konica Corporation.

Wipe residue evaluation Wipe residue means that after copying an original with a B / W ratio of 6%, the toner remaining on the photoreceptor without being transferred to the copy paper is not removed by the toner cleaner.
A phenomenon in which a defective image such as unevenness or black spots is formed on a copied image under the influence of the toner remaining on the photoreceptor. The photoreceptor surface and the copied image were ranked as follows by visual observation.

×: When a document having a B / W ratio of 6% was copied and a defective image was obtained due to unwiping on the copy image. Δ: Immediately after the photoconductor surface passed the cleaner, toner was applied to the photoconductor surface corresponding to the document. Is wiped, but it does not appear on the copied image.

：: When no unwiped residue is observed on the copy image or the photoreceptor surface.

 Table 1 summarizes the above results.

Example 2 Except that the surface roughening treatment was performed as described below,
A photoconductor was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Roughening treatment) (abbreviated as R2) Cylindrical brush (10) with a diameter of 5 cm (brush material is 6,6-
Nylon, hair thickness 5μm ~ 13μm, length about 10mm)
Was pressed against the photosensitive layer (11) as shown in FIG. 9 and rotated at 200 rpm for 5 minutes with a cylindrical brush at 60 rpm.

The surface of the organic photosensitive layer (a) had a roughness of 0.9 μm as represented by a 10-point average roughness (Rz).

Example 3 A photoconductor was prepared and evaluated in the same manner as in Example 1, except that the surface roughening treatment was performed as described below. The results are shown in Table 1.

(Roughening treatment) (abbreviated as R3) Using sandblasting method, about 0.7μ as abrasive
SiC particles having a diameter of m were bumped against the organic photosensitive layer (a) to roughen the surface.

Thereafter, the waste was lightly pressed against the photosensitive layer in pure water, and ultrasonic cleaning was performed while rotating the photosensitive layer to remove SiC particles remaining and attached to the surface of the photosensitive layer, and the photosensitive layer was dried.

Example 4 Instead of the solvent n-hexane used in the photosensitive layer cleaning treatment performed in Example 1, the following structural formula; The photosensitive layer was washed in the same manner as in the washing step of Example 1 except that the fluorinated propanol shown in (1) was used (this washing step is abbreviated as W2 in Table 1) to produce a photoreceptor. Evaluation was performed in the same manner as in Example 1.

Example 5 A photoconductor was prepared and evaluated in the same manner as in Example 1, except that the photosensitive layer cleaning treatment was performed as described below. Table 1 shows the results
It was shown to.

(Photosensitive layer cleaning effect) (abbreviated as W3) The cleaning process used in this example will be described with reference to FIGS. 10 to 12, (101) is a cleaning tank, (102) is a boiling solvent, (103) is a heat source, (104) is a solvent vapor layer, (105) is cooling water, and (106) is a condensate. Gutter,
(107) is a condenser, (108) is cooling water, (109) is air /
The vapor interface, (110) is the photoreceptor. Although not shown, a lid may be provided above the cleaning tank (101).

Using the cleaning apparatus having the above-mentioned structure, Freon-113 (CCl ₂ FCClF ₂ ; 1,1,2-trichloro-1,2,2-trifluoroethane) was used as a solvent, and the solvent vapor phase (104) was used. The cold photoconductive layer (110) was put in, the vapor was condensed and liquefied on the surface of the photoconductive layer by the temperature difference between the photoconductive layer and the vapor, and the photoreceptor was roughly flown by the droplet for about 33 seconds (FIG. 11). The temperature of the photosensitive layer rises,
The vapor was no longer liquefied on the surface of the photosensitive layer, and when the equilibrium state of absorption and desorption of the vapor was maintained, the photoconductor was pulled up (No.
12).

Example 6 A photoconductor was prepared and evaluated in the same manner as in Example 1, except that a silicon oxide film (abbreviated as SiO film) was formed as a surface protective layer by a vacuum deposition method as described below. Table 1 shows the results
Shown inside.

(Formation of SiO film) Using an ordinary person's vacuum heating evaporation system, the following conditions were used: evaporation source: SiO substrate temperature: 50 ° C port temperature: 1200 ° C vacuum degree: 8 × 10 ^-5 Torr evaporation time: 5 minutes A thin film of SiO was provided at a thickness of 1300 mm.

Example 7 A photoconductor was prepared and evaluated in the same manner as in Example 1, except that an aluminum oxide film (abbreviated as Al ₂ O ₃ film) was formed as a surface protective layer by a sputtering method as described below.

(Formation of Al ₂ O ₃ film) Using a conventional sputtering apparatus, the following conditions: Target: Al ₂ O ₃ substrate temperature: 50 ° C. Discharge interval: 50 mm (distance between target and substrate) Degree of vacuum: 2 × 10 ^{− 5} Torr Discharge gas: Ar Discharge power: 2.0 kW Discharge frequency: 13.5 MHz Discharge time: 12 minutes Film thickness: 1800Å Example 8 A photoconductor was prepared in the same manner as in Example 1, except that the organic photoconductor (b) was used. And evaluated. The results are shown in Table 1.

Example 9 In Example 1, the order in which the photosensitive layer surface was washed and then subjected to surface roughening was replaced with the reverse order, ie, the order in which the photosensitive layer surface was roughened and the surface was washed. A photoconductor was prepared and evaluated in the same manner as in Example 1 except for the above. The results are shown in Table 1.

Comparative Example 1 A photoconductor was prepared and evaluated in the same manner as in Example 1, except that the surface roughening treatment was not performed. The results are shown in Table 1.

Comparative Example 2 A photoconductor was prepared and evaluated in the same manner as in Example 1 except that the photosensitive layer was not washed and the surface roughening treatment was not performed. Table 1 shows the results
It was shown to.

Example 10 In Example 1, except that pure water was replaced with an abrasive solution in which an abrasive (manufactured by Fumi Abrasives Co., Ltd .; WA # 6000) was dispersed in pure water at a concentration of 2.5 g / g, was used. A photoconductor was prepared and evaluated in the same manner as in Example 1.

Effect of the Invention When an organic photoreceptor having a vacuum thin film on its surface as a surface protective layer is manufactured according to the present invention, there are no problems of poor toner cleaning, increase in residual potential due to repeated use, and generation of black streak accompanying this.

[Brief description of the drawings]

1 to 4 are diagrams schematically showing various aspects of buff polishing. FIG. 5 is a diagram showing a schematic configuration example of a photosensitive layer cleaning device. FIG. 6 is a diagram showing a schematic configuration example of a buff polishing apparatus used in the embodiment. FIG. 7 is a diagram for explaining buffing. FIG. 8 is a diagram showing a schematic configuration example of a glow discharge decomposition device. FIG. 9 is a view schematically showing one mode of brush polishing. FIG. 10 to FIG. 12 are diagrams for explaining the steam cleaning method.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Masaki 2-3-13-1 Azuchicho, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Shuji Iino Azuchi, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Camera Co., Ltd., 2-313 Machi (72) Inventor Is Kiyoshi Osawa Osaka International Building Minolta Camera Co., Ltd. 2-3-13 Azuchicho, Chuo-ku, Osaka City, Osaka (72) Inventor Fumiko Maekawa 2-3-3, Azuchicho, Chuo-ku, Osaka City, Osaka Prefecture Osaka International Building Minolta Camera Co., Ltd. (56) References JP-A-3-152545 (JP, A) JP-A-3-152547 (JP, A JP-A-3-152546 (JP, A) JP-A-62-58257 (JP, A) JP-A-57-74744 (JP, A) (58) Fields investigated (Int. . ^6, DB name) G03G 5/00 - 5/16

Claims (1)

(57) [Claims] A step of washing the organic photosensitive layer with a solvent having an action of removing an oxide film on the surface of the organic photosensitive layer;
Forming a vacuum thin film as a surface protective layer after the step of roughening the surface of the organic photosensitive layer.