JPH03152546A - Production of photosensitive body - Google Patents

Abstract

PURPOSE:To prevent the degradation and fluctuation in surface potential by subjecting a photosensitive layer to a mechanical rubbing treatment before the layer is coated with a vacuum thin film. CONSTITUTION:The mechanical rubbing treatment includes a means for rubbing by waste cloth, means for rubbing by a blade, means of rubbing by a brush, means of rubbing the plural photosensitive bodies against each other, etc. Adequate adhesiveness is not obtainable even if a surface protective layer is formed afterward if the stock removal is too small. The degradation in the surface charge potential by the decrease in the film thickness of the photosensitive layer arises if the stock removal is too large. The surface protective layer (vacuum thin film) is formed by various methods, such as plasma CVD method, photo CVD method, thermal CVD method,sputtering method, vapor deposition method, and ion plating method, on the surface of the photosensitive layer having the surface mechanically rubbed in such a manner. The good photosensitive body which is free from the degradation in surface potential, the fluctuation in the surface potential, etc., is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing an organic photoreceptor having a protective layer on its surface.

BACKGROUND ART Photoreceptors are generally manufactured by forming a photosensitive layer on a conductive substrate and then forming a surface protective layer.

Ideally, it is desirable to form the surface protective layer on the surface of the photosensitive layer immediately after forming the photosensitive layer; however, in practice, only the photosensitive layer is formed to simplify the manufacturing process and due to equipment problems.
Generally, a large amount of photosensitive material is manufactured at one time, and then subjected to a process of forming a surface protective layer such as an amorphous carbon film, during which time the photosensitive layer is stored for about a few days to a month ( This storage time is often referred to as "starting time").

After formation, the surface of the photosensitive layer is oxidized by oxygen in the atmosphere over time. When attempting to provide a protective layer, such as an amorphous carbon film, on the surface of a photosensitive layer on which such an oxide film is formed, the surface protective layer may peel off due to poor adhesion between the oxide film surface and the protective layer. It will happen. According to the experience of the present inventors, this phenomenon already occurs in a photosensitive layer that has been prepared for one day.

In order to remove such an oxide film, conventionally, the surface of the photosensitive layer has been washed with a general halogen-based cleaning solvent typified by Freon. In this way, the oxide film is certainly removed from the organic photosensitive layer, and the adhesion between the photosensitive layer and the surface protective layer is ensured, but the organic photosensitive layer R1 is degraded and the surface potential decreases and varies. There is a problem. In the case of an inorganic photosensitive layer, the oxide film cannot be effectively removed even under fairly severe cleaning conditions, and the adhesion between the photosensitive layer and the surface protective layer cannot be ensured.

Note that an electrophotographic photoreceptor formed of a surface protective layer or a vacuum thin film is disclosed in, for example, Japanese Patent Application Laid-Open No. 62-07E6.62-294.
258.51i39340.4935036.48-1
28732.4'l-122337,58-59454
,61117562,58-152255,63-97
As disclosed in Japanese Patent No. 962, etc., before forming a vacuum thin film on the surface of a photosensitive layer that has been stored for a long period of time, it is necessary to perform a rubbing treatment on the photosensitive layer to be coated to ensure adhesion. I haven't mentioned or suggested anything.

Problems to be Solved by the Invention The present invention has been made in view of the above circumstances, and it effectively removes the oxidized layer of the photosensitive layer, secures the adhesion between the photosensitive layer and the surface protective layer, and further improves the surface potential. It is an object of the present invention to provide a method for manufacturing a photoreceptor without any decrease or variation in the photoreceptor.

This purpose is achieved by forming a surface protective layer after scraping off a certain amount of the surface of the photosensitive layer.

Means for Solving the Problems The present invention provides a method for manufacturing a photoreceptor in which a vacuum thin film is provided on a photosensitive layer as a surface protective layer, in which the photosensitive layer is mechanically subjected to a rubbing treatment or a rubbing treatment on the surface covered with the vacuum thin film. The present invention relates to a method for manufacturing a photoreceptor, characterized in that:

The mechanical rubbing process in the present invention is to scrape off a certain amount of the surface layer of the photoreceptor, and examples of such means include, but are not limited to, rubbing with a rag, rubbing with a blade, and scraping with a brush. Examples include means for rubbing, means for rubbing a plurality of photoreceptors against each other, and the like.

The amount of abrasion is 30A to 2μm1, preferably 90A to Ipm
It is. If the amount of abrasion is small, suitable adhesion cannot be obtained even if a surface protective layer is formed later, and if the amount of abrasion is too large, a decrease in surface charging potential occurs due to a reduction in the thickness of the photosensitive layer.

The photosensitive layer to which the mechanical rubbing treatment of the present invention is effective is not particularly limited, and can be applied to both organic and inorganic photosensitive layers.

The organic photosensitive layer may contain charge generating substances such as phthalocyanine pigments, azo thread pigments, perylene pigments, etc. and charge transport substances such as triphenylmethane compounds, triphenylamine compounds, hydrazone compounds, styryl compounds, pyrazoline compounds, oxazole, etc. A single layer structure in which a compound, oxadiazole compound, etc. is dispersed and coated on a binding material such as polyester, polyvinyl butyral, polycarbonate, polyarylate, styrene acrylic, etc., or a charge generating substance and a charge transporting substance in separate layers. It can be applied to a functionally separated structure in which charge generation and charge transport functions are separated by dispersion coating (the stacking order may be in any order). Alternatively, it may be a photoreceptor made of a vapor-deposited layer made of the charge transport material itself.

The present invention can be applied to various inorganic photosensitive layers in which oxidative deterioration is a problem, such as amorphous selenium, amorphous silicon, and amorphous carbon.

A surface protective layer is applied to the surface of the photosensitive layer whose surface has been mechanically rubbed as described above by various methods such as plasma CVD method, photo CVD method, thermal CVD method, sputtering method, vapor deposition method, ion blating method, etc. (vacuum thin film) can be formed with good adhesion, and the resulting photoreceptor can be of good quality without a decrease in surface potential or variation in surface potential.

Preferably, before forming a vacuum thin film, dust generated by rubbing and remaining on the surface of the photosensitive layer is removed by blowing away with air or by cleaning with a solvent such as water or alcohol.

The present invention will be further explained below with reference to Examples.

Preparation of Large Dust Organic Photosensitive Layers (a) to ('') Organic photosensitive layers (a) to (f) were prepared as follows.

Among these photosensitive layers, the photosensitive layer (b) is for positive charging, and the other photosensitive layers are for negative charging.

Further, the photosensitive layer (") is for long wavelength exposure, and the other photosensitive layers are for normal white light exposure.

Preparation of photosensitive layer (a): A mixed solution containing the hisazo pigment chlorodiane blue (part by weight of CD), 1 part by weight of polyester resin (manufactured by Toyobo Co., Ltd.; V-200), and 100 parts by weight of cyclohexanone was prepared using a sand grinder. The dispersion was dispersed for 13 hours. This dispersion was applied by dipping onto a cylindrical aluminum substrate with a diameter of 80 mm and a length of 33 Qm+n, and dried to a film thickness of 0.3 μm.
A charge generation layer of m was formed.

Separately, 11 parts of 4-diethylaminobenzaldehyde-diphenylhydrazone (DEH) and 1 mffi part of polycarbonate (manufactured by Ondai Kasei Co., Ltd., Ni-1300) were dissolved in 6 BR parts of tetrahydrofuran (THF), and this solution was added to the charge generating solution. The layer was coated and dried to form a charge transport layer having a thickness of 15 μm after drying, thereby obtaining an organic photosensitive layer (a).

Preparation of organic photosensitive layer (b) 25 parts by weight of special α-type copper phthalonanine (manufactured by Toyo Ink Co., Ltd.), acrylic melamine thermosetting resin (manufactured by Dainippon Ink Co., Ltd., a mixture of A-405 and Super Beckamine J820)
A mixture of 50 parts by weight, 25 parts by weight of 4-diethylaminobenzaldehyde-diphenylhydrazone, and 500 parts by weight of an RF mechanical solvent (a mixture of Kin 1 Fufu and 3 parts by weight of butanol) was pulverized and dispersed in a ball mill for 10 hours. This dispersion was applied by dipping onto a cylindrical aluminum wipe plate with a diameter of 80 mm and a length of 330 mm, dried and baked (1 hour at 150°C) to form an organic photosensitive layer (b) with a thickness of 15 μm. Obtained.

2 parts by weight of a bisazo compound represented by formula [Ia] below, 1 part by weight of polyester resin (manufactured by Toyobo Co., Ltd.; v-500),
and methyl ethyl ketone 10 (0111 parts) were mixed and dispersed in a ball mill for 24 hours.
It was applied by dipping onto a cylindrical aluminum substrate measuring 330mm x 330mm in length and dried to obtain a charge generation layer with a thickness of 3000mm.

Next, a solution prepared by dissolving 10 parts by weight of a hydrazone compound represented by the formula [Ib] below and 10 parts by weight of polycarbonate resin (manufactured by Ondai Kasei Co., Ltd.; K1300) in 80 parts by weight of tetrahydrofuran was then placed on the charge generation layer. Apply,
This was dried to form a charge transport layer with a thickness of 20 μm, thereby obtaining an organic photosensitive layer (c).

Preparation of organic photosensitive layer (d) 2 parts by weight of a bisazo compound represented by the following formula [11a],
1 part by weight of polyester resin (manufactured by Toyobo Co., Ltd., v-500) and 100 parts of methyl ethyl ketone were mixed and dispersed in a ball mill for 24 hours. The diameter of this dispersion is 80I.
IIn+ was applied onto a cylindrical aluminum substrate with a length of 330+ m by dipping and dried to form a charge generation layer with a thickness of 2500 m.

Then, styryl compound 10 represented by the formula [nb] below
Parts by weight, and polyarylate resin (manufactured by Unitika, U
-4000) 0 parts by weight of I was dissolved in 85 parts by weight of tetrahydrofuran. The obtained coating solution was applied onto the charge generation layer and dried to form a charge transport layer having a thickness of 20 μm, and then an organic photosensitive layer (d) was applied.

Preparation of organic photosensitive layer (e) 2 parts by weight of a bisazo compound represented by the following formula [1rla], 1 part by weight of polyester resin (manufactured by Toyobo Co., Ltd., v-500), and 100 parts by weight of methyl ethyl ketone were mixed in a ball mill for 24 hours. Dispersed. The diameter of this dispersion is 80m.
It was coated by dipping onto a cylindrical aluminum substrate of m x length of 330 mm and dried to form a charge generation layer with a thickness of 3000 mm.

Next, 10 parts by weight of a styryl compound represented by the formula [1 [1b] below] and 10 parts by weight of methyl methacrylate resin (manufactured by Mitsubishi Rayon Co., Ltd., BR-85) were dissolved in 85 parts by weight of tetrahydrofuran. The resulting liquid was coated on the charge generation layer and dried to form a charge transport layer with a thickness of 20 μm, and subjected to organic photosensitive 8mm (e).

Preparation of organic photosensitive layer (f) Titanyl phthalocyanine (TiOPc') was heated using a resistance heating method at a boat temperature of 400 to 500'C1 vacuum level 10-
Vacuum evaporated under 4~I O-'Torr, thickness 25
A Ti0Pc deposited film was formed as a charge generation layer.

Next, p,p-bisdiethylaminotetraphenylbutadiene lff1fitL shown in the formula [rV] below and polycarbonate 1- (manufactured by Ondai Kasei Co., Ltd., 1300 parts by weight) were dissolved in 6 parts by weight of THF, and this solution was dissolved in 6 parts by weight of THF. A charge transport layer having a thickness of 15 μm was formed by coating on the charge generation layer and drying to obtain an organic photosensitive layer (f).

[Formula]] fFormula 11ral L2■] The photosensitive layer obtained as above was stored in an environment of 20° C. and 65% for 30 days, and then rubbed with a cloth as shown in FIG. It was scraped off by rubbing with a blade as shown in Figure 2.

Rubbing with a cloth In FIG. 1, (1) is a photosensitive drum having a photosensitive layer provided on a base, which is rotatably mounted. (2) is a felt cloth that is pressed against the photosensitive drum (1), and can be rolled up and moved by a roll (3).

In this embodiment, the photosensitive drum (1) of the rag (2)
(obtained from the contact area and contact pressure between the rag and drum), drum rotation speed (peripheral speed (cm/5ec)
)), the rag feeding speed (cm/min) was set to the values shown in Table 1, and the amount of scraping was measured. Note that the drum rotation direction and the rag feeding direction are indicated by arrows in the figure and are designated as l: directions.

Blade sliding In FIG. 2, (1) is a photosensitive drum provided with a photosensitive layer, which is rotatably mounted. A urethane blade is pressed against the surface of the photosensitive drum, and the photosensitive layer is scraped while rotating the photosensitive drum.

The pressing pressure was determined as pressure per unit length from the contact length and contact pressure. Pressing pressure and drum rotation speed (
The surface of each photosensitive layer was rubbed at the circumferential speed Ccm/5ec) shown in Table 1, and the amount of scraping was measured.

Note that the drum was rotated in the direction of the arrow in the figure.

Measurement of the amount of abrasion A portion of the photosensitive layer was removed using a solvent in spots on the photosensitive layer, and the thickness of the photosensitive layer was measured using a surface roughness meter (Surfcom 550A manufactured by Tokyo Seimitsu Co., Ltd.). The amount of wear was calculated. For those whose amount of scraping was small and within the measurement error range, the amount of scraping was measured during long-time processing, and the amount of scraping was determined from the ratio of the processing times.

The results are shown in Table 1.

Immersion cleaning (comparative example) Regarding the immersion cleaning used in the comparative example, the internal volume is 30 (vertical) x 3
A solvent was placed in a cleaning tank measuring 0 (horizontal) x 50 (height to liquid level) cm', and cleaning was performed by dipping at a liquid temperature of 20° C. for a certain period of time (as shown in Table 1).

The results are shown in Table 1.

Formation of surface protective layer After the surface of the photosensitive layer was scraped by a predetermined amount, a surface protective layer was provided on the surface of the photosensitive layer (a) as follows.

In the glow discharge decomposition apparatus shown in FIG.
8) and hydrogen gas from the first tank (701) and butadiene gas from the second tank (702) at an output pressure of 1.
．． Under 0 kg/cm2, the first and second flow controllers (
713 and 714). Then, adjust the scale of each flow rate controller to adjust the flow rate of hydrogen gas to 300 s.
ecm, the flow rate of butadiene gas is set to 3Qsccm, and the main pipe (
732) into the reaction chamber (733). After each flow rate stabilizes, the pressure in the reaction chamber (733) is 0.5
The pressure regulating valve (745) was adjusted so that the pressure was Torr. On the other hand, as the substrate (752), the organic photosensitive layer (a)
Heat the gas to 50°C in advance using the gas flow rate and pressure, and then turn the connection selection switch (744
), the low frequency power supply (741) connected to the substrate (752 ) top thickness 120
0 amorphous carbon [II (a-'C film) was formed as a surface protective layer. After the film formation was completed, the power application was stopped, the control valve was closed, and the inside of the reaction chamber (733) was sufficiently evacuated, and then the vacuum was broken and the photoreceptor of the present invention was taken out.

Photosensitive layers (b) to (f) were also formed in the same manner as above under the conditions shown in Table 1.

Measurement of Photoreceptor Surface Potential (Before Formation of Surface Protective Layer) As shown in FIG. 4, a photosensitive drum (1O) before forming the surface protective layer was attached and rotated at a circumferential speed of 130 mm/see. High voltage power supply (12X~10DEL610A;
Power is supplied from the Corotron charger (manufactured by TREK) to the Corotron charger (manufactured by TREK).
13), and the surface of the photosensitive layer was charged to 500μ.

The charging potential was measured using a surface electrometer (14XMODEL362A;
(manufactured by TREK) and read the current a and uA at that time with an ammeter (11).

As shown in FIG. 5, surface electrometers were installed at three locations in the longitudinal direction of the drum, and were placed on the top, middle, and bottom of the drum, and the potentials at the corresponding locations were simultaneously measured. Note that the above-mentioned ammeter reading a[μA1 indicates the reading when the average of the three surface electrometers is 500V, but in all experiments, the variation in surface potential at the top, middle, and bottom of each drum was It was within ±5V.

Finally, the electrostatic charge is removed using an eraser lamp (tungsten lamp, -40 [1ux sec] at a color temperature of 2800°).
was irradiated and erased.

(After forming the surface protective layer) Next, attach the photosensitive drum on which the surface protective layer has been formed, adjust the output of the charger (13) so that the reading value of the ammeter (l l) becomes a[μA1 again, The surface potential at each position on the top, middle, and bottom of the drum was read using two surface potential meters (14), and the evaluation results were expressed using the following symbols according to the range of decrease from the initial surface potential of 500 V.

(Variation evaluation) Evaluation results are shown according to the difference between the maximum value and the minimum value of the surface potential fluctuation within the circumference. The surface potential has a representative value that is an intermediate value between the maximum value and the minimum value.

Adhesion Evaluation The adhesion of the surface protective layer was evaluated using a substrate test according to JIS-5400 standards at three locations (top, middle, and bottom) of the photosensitive drum (FIG. 5).

Longitudinal V. Regarding dispersion, evaluate the maximum and minimum values for the top, middle, and bottom three locations in the same way.

Image Evaluation The obtained photoreceptor (with a protective layer) was mounted on an actual copying machine, and the obtained copy image was visually judged.

The copying machine used was EP490Z (manufactured by Minolta). However, the photoconductor using the photosensitive layer (b) was modified so that the charging and development polarity was reversed, and the photoconductor using the photoconductor layer ([) was modified to have a semiconductor laser system. I used something.

O indicates a good image, △ indicates an image with no practical problems,
× indicates an unsuitable image.

The evaluation results for each photosensitive layer are summarized in Table 1.

(Hereafter, blank space) In Example 1-11, a cloth rubbing method was applied to the organic photosensitive layer (a) using the apparatus shown in FIG. 1, and the rubbing conditions and the amount of scraping were adjusted. This was evaluated in various ways.

When the amount of scraping is small (Example 1.4), there are cases where the adhesiveness is slightly poor, but there is no practical problem and Comparative Examples 5 to 1
Very good results were obtained compared to 0. Also,
When the amount of abrasion is large (Example It), there are cases in which a slight decrease in surface potential is observed, but there is no practical problem, and extremely good results are obtained compared to Comparative Example 2.4.

When the amount of abrasion is 908 to I μm, good results with no problems are obtained (Example 2.3.5.
6.7.8.9.10).

It can be seen from Examples 12 to 16 that similar results can be obtained even if the rubbing method is changed as shown in FIG.

In Examples 17 to 26, it can be seen that equivalent results can be obtained even if the organic photosensitive layer is changed to something other than (a).

Comparative Examples 1 to 4 are as follows: - After using a fluorocarbon solvent, which is often used as a cleaning agent for boat fishing, on the photosensitive layer (a),
-C A surface protective layer is provided.

It can be seen that the adhesion was improved because the oxide film was removed. However, if the time of immersion in the solvent is long, the surface potential after coating is lowered, and therefore, Comparative Example 2.4 is ranked as poor or poor.

Since a decrease in image density due to this decrease in surface potential was also observed on the image, the image evaluation rank was expressed as ×.

On the other hand, if the time spent immersed in the solvent is short, the influence of dripping occurs during cleaning, and the areas where the liquid drips, that is,
A difference in surface potential occurs between the part where the solvent has been attached to the photoreceptor surface for a long time and the part where it has not, and the vo
The variation becomes larger.

V in Comparative Example 1.3. This is the reason why the dispersion evaluation rank is ×. Image noise with very noticeable drip-like shading was also generated on the image, so the image evaluation rank was expressed as ×.

Thus, it can be seen that the solvent cleaning treatment does not give good results.

In Comparative Examples 5 to IO, photosensitive layers (a) to ('') (stored for 30 days after the photosensitive layer preparation) to be used in the examples of the present invention were a- A C surface protection layer is provided.

As shown in the adhesive evaluation, all adhesive ranks are X,
It is understood that the oxide film due to long-term storage has an adverse effect on the adhesion of the a-C film. Needless to say, if the a-C film is not adhered, the original purpose of the overcoat, which is to extend the life of the photoreceptor, cannot be achieved.

In addition, spontaneous peeling occurred without the need to conduct a substrate surface test, resulting in a difference in surface potential between the areas with and without the overcoat layer, and the V0 variation evaluation was ranked as not having any practical problems. .

In image evaluation, as a result of peeling pieces a-C adhering to the copy image, peeling pieces getting into the developing device and getting caught between the height regulating plate and the developing sleeve, or between the photoreceptor and the developing sleeve,
This resulted in extremely undesirable results such as blocking the flow of the developer and causing so-called development defects. Image evaluation rank ×
shows this.

Furthermore, instead of the a-C film as a surface protective layer (QC layer), using a commonly used sputtering device, the following conditions were applied: Target: A (box, substrate temperature: 50°C, discharge interval: 50 mm (distance between target and substrate). ) Vacuum degree: 2 x ] O-'Torr discharge gas
:Ar Discharge power: 2. OKW Discharge frequency: 13.56MHz Discharge time: 12 minutes 00 layer film thickness: 120. Photoreceptors were produced and evaluated in the same manner as in Example 1, Comparative Example 1, and Comparative Example 5, except that the thin film was provided.

The results were equivalent to Example 1, Comparative Example 1, and Comparative Example 5.

In addition, instead of the a-C film as the surface protective layer, a commonly used evaporation apparatus using a vacuum heating method was used, and the following conditions e1 were applied: Vapor deposition source: SiO Substrate temperature: 50°C Boat temperature: 12000C Vacuum degree: 8 X I O -'Torr deposition time
: 5 minute OC layer thickness: Photoreceptors were prepared and evaluated in the same manner as in Example 11 Comparative Example I and Comparative Example 5, except that the SiO thin film was formed by 1300 people.

The results were equivalent to Example 1, Comparative Example 1, and Comparative Example 5.

From the above, it is understood that the present manufacturing method is applicable not only to a-C films but also to vacuum thin films in general.

Effects of the invention Vacuum thin film (amorphous carbon film) with good adhesion without causing a decrease in the surface potential of the photoreceptor or variations in surface potential.
can now be formed as a photoreceptor surface protective layer.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a schematic configuration of rubbing cloth. FIG. 2 is a diagram showing an example of a schematic configuration of blade sliding. FIG. 3 shows an example of a schematic configuration of a glow discharge decomposition apparatus for forming a surface protective layer. FIG. 4 shows an example of a schematic configuration of a photoreceptor surface potential measuring device. FIG. 5 is a diagram showing the surface potential measurement site of the photoreceptor.

Claims (1)

[Claims] 1. In a method for manufacturing a photoreceptor in which a vacuum thin film is provided as a surface protective layer on a photosensitive layer, the photosensitive layer is subjected to a mechanical rubbing treatment before being covered with the vacuum thin film. A method for manufacturing a photoreceptor, characterized by: 2. The method of manufacturing a photoreceptor according to claim 1, wherein the photosensitive layer is an organic photosensitive layer containing at least a charge-generating material and a charge-transporting material. 3. The method for manufacturing a photoreceptor according to claim 1, wherein the vacuum thin film is an amorphous carbon film produced by a plasma CVD method. 4. The method for manufacturing a photoreceptor according to claim 1, wherein the surface of the photoreceptor is scraped by 30 Å to 2 μm by rubbing.