JPH04242746A - Image forming method - Google Patents

Abstract

PURPOSE:To provide an image forming method capable of forming an image without accompanying the generation of a spot (stain) and an interference fringe (moire), exhibiting stable potential characteristic even in the case of repeatedly forming the image, and never reducing the image quality. CONSTITUTION:By use of an electrophotographic sensitive body obtained by providing a photoconductive sensitive layer on an electrophotographic sensitive base body having a surface roughness of 0.3-2.0mum Rmax obtained by cutting the surface of an electrophotographic sensitive base body material 1 by a bite 8 while supplying a water cutting solution thereto, an image is formed by reverse developing method.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an image forming method,
Specifically, the present invention relates to a method of forming an image by a reversal development method using an electrophotographic photoreceptor equipped with a specific substrate.

0002

[Prior Art] In electrophotographic copying machines, digital copiers, laser printers, etc., electrophotographic photoreceptors are formed by providing a photosensitive layer on a rotating drum-shaped electrophotographic photoreceptor substrate (hereinafter appropriately abbreviated as "substrate"). is widely used. As the material for the substrate constituting such an electrophotographic photoreceptor, aluminum-based materials are preferably used because of their advantages such as low cost, light weight, and ease of processing. This rotating drum-shaped base made of an aluminum-based material is generally finished by cutting the surface of a tubular material, and a cutting fluid is usually used during this cutting process. This cutting fluid is used for the purpose of cooling, lubricating, cleaning, etc., and specifically, petroleum-based, polybutene-based, kerosene, white kerosene, etc. are used. Furthermore, in order to prevent the occurrence of image defects, the surface of the substrate is also cleaned by a contact type cleaning means using a brush, an abrasive, etc. after cutting the substrate.

As specific techniques related to surface processing methods for electrophotographic photoreceptor substrates, the following have been proposed. (1) Oiliness improver and/or extreme pressure additive 1.0
A technique for processing an electrophotographic photoreceptor substrate using a cutting oil containing less than % by weight (Japanese Patent Laid-Open No. 63-307463). (2) Technology for finishing the surface of an electrophotographic photoreceptor substrate made of an aluminum alloy containing magnesium, silicon, copper, and titanium in proportions in a specific range using a cutting tool with a rounded cutting part (Japanese Patent Laid-Open No. 64-86151) Publication No.). (3) Technology using an electrophotographic photoreceptor substrate made of an aluminum alloy containing silicon and iron in a specific range of proportions
(Japanese Unexamined Patent Publication No. 1986-86152). (4) A technique for finishing the surface of an electrophotographic photoreceptor substrate made of an aluminum alloy containing magnesium, silicon, and copper in proportions in a specific range using a cutting tool with a rounded cutting part (Japanese Patent Application Laid-Open No. 86153/1986) ). (5) Technology using an electrophotographic photoreceptor substrate made of an aluminum alloy containing silicon, magnesium, and iron in proportions within a specific range (Japanese Unexamined Patent Publication No. 86154/1986)
. (6) A technique using an electrophotographic photoreceptor substrate made of an aluminum alloy containing magnesium, silicon, copper, and titanium in proportions within a specific range (Japanese Patent Laid-Open No. 86155/1983). (7) silicon, iron and magnesium in proportions within a specific range;
A technique using an electrophotographic photoreceptor substrate made of an aluminum alloy containing a specific proportion or less of other metals (Japanese Unexamined Patent Publication No. 1-123245). (8) Technology using a surface processing device that is composed of a lathe unit, a high-pressure liquid injection processing unit, and an electrophotographic photoreceptor substrate conveyance unit, and is capable of sequentially and automatically performing lathe processing and high-pressure injection processing. (Unexamined Japanese Patent Publication No. 1-172573). (9) Technology using a specific cutting fluid supply nozzle device having a spindle head that rotatably supports a spindle including a rotary tool with an oil hole and a rotary tool without an oil hole (Japanese Patent Laid-Open No. 62-152642) Public bulletin). (10) While spraying high-pressure water onto the surface of the electrophotographic photoreceptor substrate from the injection hole of a nozzle connected to a high-pressure water supply source, scan the nozzle along the surface of the substrate to A technique for roughening a surface to a predetermined surface roughness (Japanese Unexamined Patent Publication No. 63-264764).

0004

[Problems to be Solved by the Invention] However, in the above-mentioned prior art, aluminum cutting powder,
Environmental foreign substances such as dust and dirt, rust, etc. may be incorporated into the cutting oil and firmly adhere to the base. If this condition is left for a long period of time, for example one month or more,
Especially under high temperature and high humidity conditions in the summer, the above deposits become even more firmly attached, causing local corrosion (rust) to occur on the surface of the substrate, and this corrosion may not be visible to the naked eye. be. Such corrosion cannot be completely removed by immersion in organic solvents or surfactant solutions, or by non-contact cleaning such as ultrasonic cleaning or ultraviolet/O3 irradiation cleaning; therefore, such corrosion does not exist. When an electrophotographic photoreceptor is constructed by providing a photosensitive layer on the surface of a substrate to be processed, image defects occur in the corroded areas, and especially when applied to an image forming process that employs a reversal development method, spots (dots) appear in the resulting image. There are problems such as stains), striped stains, and localized fogging.

[0005] Partial corrosion on the substrate surface can be removed to some extent by contact cleaning the substrate surface with a brush or abrasive, but depending on the aluminum material, the substrate surface may be scratched instead. Since the thickness of the photosensitive layer, particularly the carrier generation layer, formed on the scratched portion is likely to change, the photosensitivity of the photosensitive layer changes, causing contrast in the halftone image, resulting in image defects.

[0006] Furthermore, the surface roughness is 0.3 to 2.0 μ.
mRmax, 5 to 5 to 0.1mm in length
In a base made of an aluminum material in which 15 "undulations" with micro-roughness exist, in the recesses of micro-roughness,
Oil, cutting powder, environmental foreign matter, etc. enter the image forming apparatus, and if left unattended, they will stick to the surface, and these stuck substances cannot necessarily be removed with brushes or abrasives alone, causing image defects.

In addition, when applied to the exposure process using laser light, there is a problem that interference fringes (moiré) are likely to occur, and in particular, in digital full color copiers, there are many photographic images as documents, so some parts of the image are Even if interference fringes occur, it will be a serious defect. Furthermore, in order to improve color reproducibility, it is necessary to suppress the occurrence of spots that cause color mixing with other colors as much as possible, but this problem has not yet been solved.

The inventors of the present invention have conducted extensive research to solve the above problems, and have found that the occurrence of image defects is caused by the cutting powder, environmental foreign matter, etc. generated during surface processing of the substrate, using the cutting oil as a binder on the substrate surface. It was discovered that the cause of the problem was that the cutting oil itself was decomposed and firmly stuck, or that it was caused by a chemical reaction. They also discovered that by cutting with a cutting tool using a water-based cutting fluid instead of cutting oil, it is possible to obtain an electrophotographic photoreceptor that has fewer image defects, is easy to clean afterward, and is suitable for reversal development. As a result, the present invention was completed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an image forming method that does not generate spots or interference fringes (moiré). Another object of the present invention is to provide an image forming method that exhibits stable potential characteristics and does not reduce image quality even when images are repeatedly formed.

0010

[Means for Solving the Problems] In the image forming method of the present invention, a surface roughness obtained by cutting the surface of an electrophotographic photoreceptor substrate material with a cutting tool while supplying an aqueous cutting fluid to the surface of the substrate material is 0.0. It is characterized in that an image is formed by a reversal development method using an electrophotographic photoreceptor in which a photoconductive photosensitive layer is provided on an electrophotographic photoreceptor substrate having an Rmax of 3 to 2.0 μm. Further, the water-based cutting fluid is characterized in that it is a mixture of water and a surfactant or water and a water-soluble organic solvent. Furthermore, the surface of the electrophotographic photoreceptor substrate that has been cut is characterized by the presence of "undulations" having 5 to 15 microroughnesses within a length of 0.1 mm.

[0011]

[Operation] By using a water-based cutting fluid, welding and adhesion of environmental foreign substances such as cutting powder, dust, and dirt to the substrate surface can be effectively prevented. Even if any deposits occur, they will not stick firmly, making subsequent cleaning easier. Therefore, when applied to a reversal development method, it is possible to form an image free of spots, stripes, and partial fog. Furthermore, the surface roughness of the electrophotographic photoreceptor substrate is 0.3 to 2.0 μmR.
max, the generation of interference fringes (moiré) can be effectively prevented when applied to an exposure process using laser light, such as in a digital copier or laser printer.

0012

[Example] The electrophotographic photoreceptor used in the present invention has a surface roughness obtained by cutting the surface of the electrophotographic photoreceptor substrate material with a cutting tool while supplying an aqueous cutting fluid to the surface.
This is an electrophotographic photoreceptor comprising a photoconductive photosensitive layer provided on an electrophotographic photoreceptor substrate having an Rmax of 0.3 to 2.0 μm.

Materials for the electrophotographic photoreceptor substrate include:
Aluminum-based materials are preferred. Specifically, JIS
A1070, A1100, A3003 specified in
, A5005, A5805, A6063, etc. are used. The shape of the base material is not particularly limited, and may be either a rotating drum shape or an endless seat belt shape.

[0014] Water-based cutting fluid is used during cutting. The aqueous cutting fluid is preferably supplied to the surface of the base material in the form of a mist using, for example, a needle spray gun. By using a water-based cutting fluid in the form of a mist, it is possible to effectively prevent cutting dust and environmental foreign matter generated during cutting from firmly adhering to the base material surface, and also prevent cutting dust from entering into the micro-rough grooves. It is also easy to remove. Furthermore, it is easy to clean because cutting powder does not stick firmly to the surface of the base material, so there is no need to use fluorocarbons or chlorinated solvents, and there is no risk of environmental hygiene problems. Even when such contact cleaning is applied, sufficient cleaning can be achieved with a small scrubbing force, and there is no fear of scratches that may cause image defects on the substrate surface. Further, even if the substrate is left for a long period of time, there is no risk of cutting powder or environmental foreign matter firmly adhering to the substrate surface. Furthermore, during surface processing, a uniform and strong oxide film is formed on the surface of the base material made of aluminum-based material by a mist of water-based cutting fluid, which stabilizes the surface condition of the base material and prevents local corrosion. There is no fear.

[0015] The supply amount of water-based cutting fluid has a good cooling effect,
From the viewpoint of obtaining lubricating and cleaning effects, 0.003ml
/cm2 or more is preferable. Specific examples of water-based cutting fluids include pure water, tap water, aqueous solutions of anionic, cationic, nonionic, and amphoteric surfactants, water-soluble organic solvents such as alcohol-based and ketone-based solvents, and water-soluble organic solvents. Examples include aqueous solutions of solvents. In the present invention, a mixture of water and a surfactant or a water-soluble organic solvent is particularly preferred because it exhibits excellent cleaning properties.

As the cutting tool, a cutting tool made of a polycrystalline diamond sintered body is preferable. For rough machining, ordinary polycrystalline diamond sintered bodies are used, and for finishing machining,
Polycrystalline diamond sintered body with grain size of 0.5μ
It is preferable to use a cutting tool with a nose radius R of about 20 mm or more. By using a nose with a large radius R, the maximum height Rmax within the feed pitch of the cutting tool becomes small, resulting in a shape that allows the machining surface to be easily cleaned. That is, the maximum height R
max is small and the pitch is large. Also,
By increasing the radius R of the roundness of the nose, when the maximum height Rmax is the same, the feeding pitch of the cutting tool can be increased, which is also effective for improving takt time. Here, the maximum height Rmax is measured according to JIS B0601-1982. The measuring instrument used was JIS B
"Surface Roughness Meter SE-30H" (manufactured by Kosaka Laboratory) is a stylus-type surface roughness measuring instrument specified in 0651,
The nominal radius of curvature of the tip of the stylus used was 2 μm.

[0017] The conditions for surface machining are that for rough machining, the spindle rotation speed is 2000 to 6000 rpm, and the depth of cut is 0.
．． 1 to 0.2 mm, feed pitch 0.2 mm/re
v The degree of rotation is good, and in finishing machining, the spindle rotation speed is 200
The preferred speed is 0 to 6000 rpm, the depth of cut is 20 μm, and the feed pitch is about 0.2 mm/rev. Note that the main shaft rotation speed cannot be unconditionally defined because it also differs depending on the outer diameter of the tubular base body.

In the present invention, cutting is performed so that the surface roughness of the base material is 0.3 to 2.0 μmRmax. If the surface roughness is within this range, the generation of interference fringes (moiré) can be effectively prevented when applied to an exposure process using laser light.

[0019] In the present invention, it is preferable that "waviness" having 5 to 15 micro-roughnesses exist on the surface of the electrophotographic photoreceptor substrate that has been cut and has a length of 0.1 mm or less. . The presence of such "undulations" effectively prevents the occurrence of interference fringes (moiré). Here, the micro-roughness was measured in the same manner as the measurement of the maximum height Rmax above, and the fineness of the micro-roughness that can be measured varies depending on the radius of curvature of the tip of the stylus used. In one example, a stylus with a nominal tip radius of curvature of 2 μm is used.

Machine tools that can be used to process the surface of the substrate material are not particularly limited, but include, for example, a lathe for substrate processing shown in FIG. 1. In FIG. 1, 1 is a drum-shaped base, 2 is a magnet base, 3 is a holder, 4 is an atomizer, 5 is a spray nozzle, 6 is a cutting fluid container, 7 is an operating air valve, and 8 is a cutting tool. When the operator steps on the operating air valve 7 with his foot, air is sent to the atomizer 4, and cutting fluid, that is, water mist, is sprayed from the spray nozzle 5 of the cutting fluid container 6 onto the contact area between the cutting tool 8 and the base 1. Ru. A specific example of a cutting fluid spray device is "Magic Cut" (
(manufactured by Fuso Seiki Co., Ltd.). FIG. 2 is an enlarged view of the cutting fluid spraying device.

[0021] The surface-treated substrate is then subjected to a cleaning process, and since the surface-treated substrate as described above is easy to clean, brush cleaning with low abrasive force, ultrasonic cleaning, and pure water are used. Cutting powder and the like can be easily removed by washing or the like. Therefore, adhesion of cutting powder and the like to the surface of the substrate is sufficiently prevented. The substrate that has passed through the cleaning process is then subjected to a drying process, in which, for example, steam or the like is used as the drying means.

[0022] A photoconductive photosensitive layer is laminated on the surface of the electrophotographic photoreceptor substrate whose surface has been treated as described above, thereby constructing an electrophotographic photoreceptor. As a photoconductive photosensitive layer,
A functionally separated organic photosensitive layer including a charge generation layer and a charge transport layer is preferred.

In the present invention, an image is formed by a reversal development method using the electrophotographic photoreceptor constructed as described above. As the reversal development method, a conventionally known method can be employed.

Next, specific examples will be explained, but the present invention is not limited to these examples. Example 1 According to the following conditions, the surface of the base material was cut with a cutting tool while supplying cutting fluid to the surface of the base material. Next, it was cleaned and surface treated to an outer diameter of 180m.
An electrophotographic photoreceptor substrate having a length of 350 mm and a length of 350 mm was obtained. The surface roughness of this substrate was 1.0 μmRmax, and the number of minute roughnesses in the portions within 0.1 mm in length was 10. (1) Base: A base made of an aluminum-based material, with an outer diameter of 60 mm.
Kobe Steel's A40S (mm) with a length of 273 mm.
6000 series) was used. (2) Tap water with a cutting fluid specific resistance of 5 kΩ/cm was used. (3) Cutting fluid was supplied at a supply amount of 0.003 ml/cm2. (4) A base processing lathe shown in FIG. 1 was used, which was equipped with "Magic Cut" (manufactured by Fuso Seiki Co., Ltd.) as a machine tool cutting fluid spraying device. (5) For rough machining with a cutting tool, a cutting tool made of a polycrystalline diamond sintered body with a nose radius of 3 mm and a grain size of 5 μm was used. In the finishing process, a cutting tool made of a polycrystalline diamond sintered body with a nose radius of 20 mm and a grain size of 0.5 μm was used. (6) Machining conditions In rough machining, the spindle rotation speed was 3000 rpm, the feed pitch was 0.2 mm/rev, and the depth of cut was 0.2 mm. In finishing machining, the spindle rotation speed is 3000 rpm,
Feed pitch: 0.2mm/rev, depth of cut: 20μm
And so. (7) Cleaning Conditions Ultrasonic cleaning was performed using 1,1,1-trichloroethane, and further brush scrubbing cleaning was performed.

Using the electrophotographic photoreceptor substrate obtained as described above, an intermediate layer, a charge generation layer, and a charge transport layer are sequentially laminated in the following manner to obtain a functionally separated two-layer structure. An electrophotographic photoreceptor equipped with an organic photosensitive layer was produced.

(1) As the intermediate layer coating solvent, 9000 ml of toluene and 1000 ml of 2-butanone (MEK) were used, and as the binder, 30 g of "ELVAX 4260" (ethylene resin, manufactured by DuPont Mitsui Polychemical Co., Ltd.) was used. An intermediate layer having a dry film thickness of 0.4 μm was provided on the electrophotographic photoreceptor substrate.

(2) 10,000 m of 2-butanone (MEK) as a charge generation layer coating solvent
"KR-5240" was used as the binder (solution).
(silicone resin, manufactured by Shin-Etsu Chemical Co., Ltd.), and 20 g of τ-type metal-free phthalocyanine as a charge generating substance.
g, so that the film thickness after drying on the intermediate layer is 0.5
A charge generation layer of μm was provided. In addition, the coating liquid was prepared by dispersing it with a sand grinder for 2 hours.

(3) 10,000 ml of 1,2-dichloroethane as a charge transport layer coating solvent
ml, and “Iupilon Z-20” as a binder.
0” (polycarbonate resin, manufactured by Mitsubishi Gas Chemical Co., Ltd.) 2
A charge transport layer having a dry thickness of 20 μm was provided on the charge generation layer using 300 g of the charge transport material and 1400 g of a compound represented by the following chemical formula 1 as a charge transport material.

[0029]

[Chemical formula 1]

[0030] The above electrophotographic photoreceptor was mounted on a digital multicolor copier "Konica 8028" (manufactured by Konica), and an actual photographic test was conducted in which an image was formed by the reversal development method at room temperature and humidity (20°C, 50±10%). RH)
, high temperature and high humidity (33°C, 80±10% RH), and low temperature and low humidity (10°C, 20±10% RH), and the following items were evaluated. The above copier has 64 intermediate gradations, employs PWM (Pulse Width Modulation), and is equipped with a semiconductor laser light source as an exposure light source.

Evaluation item (1) Potential evaluation initial and 10
The unexposed potential of the electrophotographic photoreceptor at the time of 00 copies (V
H) and exposure potential (VL) were investigated. The charger used was a scorotron, and the grid potential was -600 V.
And so. (2) Evaluation of spots (dot-like dirt) The size and number of spots were measured using an image analysis device "Ominicon 3000" (manufactured by Shimadzu Corporation), and the major axis was 0.
．． Judgment was made based on the number of spots larger than 0.05 mm per cm2. Evaluation: 0 pieces/cm2: ○, 1~
The case of 10 pieces/cm2 was marked as Δ, and the case of 11 pieces/cm2 or more was marked as ×. Note that ◯ and △ are at a practical level. (3) Evaluation of interference fringes (moire) Observe the solid areas and halftone areas of the image, and mark ○ if no moire is observed, △ if some moire is observed, and × if moire is clearly observed. did.

Examples 2 to 3 Electrophotographic photoreceptors were prepared in the same manner as in Example 1, except that the conditions shown in Table 1 below were used, and a photographic test was conducted and evaluated in the same manner as in Example 1.

Comparative Examples 1 to 3 Electrophotographic photoreceptors were prepared in the same manner as in Example 1, except that the conditions shown in Table 1 below were used, and a photographic test was conducted and evaluated in the same manner as in Example 1. In addition, the cutting fluid "D 110" (
(manufactured by Esso) is a water-insoluble cutting fluid containing 54% paraffinic hydrocarbons and 46% naphthenic hydrocarbons. The results of the above Examples and Comparative Examples are shown in Tables 2 and 3 below.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

[Effects of the Invention] As explained in detail above, according to the image forming method of the present invention, an image can be formed without occurrence of spots or interference fringes (moiré), and images can be repeatedly formed. Stable potential characteristics are exhibited even when
Image quality does not deteriorate.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a base processing lathe.

FIG. 2 is a perspective view of a cutting fluid spraying device.

[Explanation of symbols]

1 Base 2 Magnet base 3 Holder 4 Atomizer 5 Spray nozzle 6 Cutting fluid container 7 Operation air valve 8 bytes

Claims (3)

[Claims] [Claim 1] Surface roughness obtained by cutting the surface of the electrophotographic photoreceptor substrate material with a cutting tool while supplying an aqueous cutting fluid to the surface is 0.3 to 2.0 μmRma.
An image forming method comprising forming an image by a reversal development method using an electrophotographic photoreceptor comprising a photoconductive photosensitive layer provided on an electrophotographic photoreceptor substrate. 2. An image forming method, wherein the aqueous cutting fluid according to claim 1 is a mixture of water and a surfactant or water and a water-soluble organic solvent. 3. A claim characterized in that "waviness" having 5 to 15 micro-roughnesses exists in a portion of 0.1 mm or less in length on the surface of the electrophotographic photoreceptor substrate that has been cut. Item 2. Image forming method according to item 1 or 2.