JP2996742B2 - Image forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method,
More specifically, the present invention relates to a method for forming an image by a reversal development method using an electrophotographic photosensitive member having a specific substrate.

[0002]

2. Description of the Related Art In electrophotographic copying machines, digital copiers, laser printers, and the like, an electrophotographic photoreceptor having a photosensitive layer provided on a rotating drum-shaped electrophotographic photoreceptor substrate (hereinafter abbreviated as "substrate" as appropriate). Is widely used. As a material for the base constituting the electrophotographic photosensitive member, an aluminum-based material is preferably used because of its advantages such as low cost, light weight, and ease of processing. The rotary drum-shaped substrate made of this aluminum-based material is generally finished by cutting the surface of a tubular material, and a cutting fluid is usually used during this cutting. This cutting fluid is used for the purpose of cooling, lubricating, cleaning and the like, and specifically, petroleum, polybutene, kerosene, white kerosene and the like are used. Further, in order to prevent the occurrence of image defects, the surface of the substrate is cleaned by a contact-type cleaning means using a brush, an abrasive, or the like after the substrate is cut.

As specific techniques related to the surface processing method of the electrophotographic photosensitive member substrate, the following techniques have been conventionally proposed. (1) A technique for processing an electrophotographic photosensitive member substrate using a cutting oil containing an oiliness improver and / or an extreme pressure additive in an amount of 1.0% by weight or less (Japanese Patent Application Laid-Open No. 63-307463). (2) Technology for finishing the surface of an electrophotographic photosensitive member substrate made of an aluminum alloy containing magnesium, silicon, copper, and titanium in a specific range by a cutting tool having a rounded cutting portion (Japanese Patent Laid-Open No. 64-86151) Publication). (3) Technology using an electrophotographic photoreceptor substrate made of an aluminum alloy containing silicon and iron in a specific range of ratio
(JP-A-64-86152). (4) Technology for finishing the surface of an electrophotographic photosensitive member substrate made of an aluminum alloy containing magnesium, silicon and copper in a specific range by a cutting tool having a rounded cutting portion (Japanese Patent Laid-Open No. 64-15353) ). (5) A technique using an electrophotographic photosensitive member substrate made of an aluminum alloy containing silicon, magnesium and iron in a specific range of ratio (Japanese Patent Laid-Open No. 64-86154). (6) A technique using an electrophotographic photosensitive member substrate made of an aluminum alloy containing magnesium, silicon, copper, and titanium in a specific range (Japanese Patent Laid-Open No. 64-86155). (7) silicon, iron and magnesium in a specific range of proportions;
A technique using an electrophotographic photosensitive member substrate made of an aluminum alloy containing a specific ratio or less of another metal (JP-A-1-123245). (8) A technology that uses a surface processing apparatus that includes a lathe unit, a high-pressure liquid jet processing unit, and a transport unit for an electrophotographic photosensitive member substrate, and enables lathe processing and high-pressure jet processing to be continuously and automatically performed. (JP-A-1-172573)
. (9) A technique using a specific cutting fluid supply nozzle device having a spindle head rotatably supporting a spindle having a rotary tool having an oil hole and a rotary tool having no oil hole (Japanese Patent Application Laid-Open No. 62-155262). Gazette). (10) While jetting high-pressure water onto the surface of the electrophotographic photosensitive member substrate from the injection holes of the nozzle connected to the high-pressure water supply source, the nozzle is scanned along the surface of the substrate to cause the nozzle to scan. Technology for roughening the surface to a predetermined surface roughness (Japanese Patent Laid-Open No. 63-264764).

[0004]

However, in the above-mentioned prior art, the surface of a substrate made of an aluminum-based material which has been surface-processed using a cutting oil is provided with aluminum cutting powder,
Environmental foreign substances such as dust and dirt, rust and the like may be firmly adhered to the substrate in a state of being taken in the cutting oil, and if this state is left for a long period of, for example, one month or more,
In particular, under high temperature and high humidity conditions in summer, the above-mentioned deposits are more firmly adhered, and partial corrosion (rust) occurs on the surface of the base, and this corrosion may not be recognized visually. is there. Such corrosion cannot be completely removed by immersion in an organic solvent or a surfactant solution, or by non-contact cleaning such as ultrasonic cleaning or ultraviolet / O ₃ irradiation cleaning. When an electrophotographic photoreceptor is formed by providing a photosensitive layer on the surface of an existing substrate,
Image defects occur in the corroded portions, and particularly when applied to an image forming process employing a reversal development method, spots (dot-like stains), stripes (strip-like stains), and local fog occur in an obtained image. There's a problem.

[0005] Partial corrosion of the substrate surface can be removed to some extent by cleaning the surface of the substrate with a brush or an abrasive, but depending on the aluminum-based material, the surface of the substrate is rather scratched. Since the thickness of the photosensitive layer formed on the flaw portion, particularly the thickness of the carrier generation layer, tends to change, there is a problem that the photosensitivity of the photosensitive layer changes and a contrast occurs in a halftone image to cause an image defect.

Furthermore, the surface roughness is 0.3 to 2.0 μm Rmax
In the case of a base made of an aluminum-based material with 5 to 15 undulations having micro-roughness in a portion within 0.1 mm in length, oil, cutting powder, environmental foreign matter, etc. And the like enter, and when left unattended, they adhere, and this adhered substance cannot always be removed only with a brush or an abrasive, thereby causing image defects.

Also, when applied to an exposure process using a laser beam, there is a problem that interference fringes (moiré) are likely to occur. However, if interference fringes occur, it becomes a serious defect. Further, in order to enhance color reproducibility, it is necessary to minimize the occurrence of spots that cause color mixture of other colors, but this problem has not been solved yet.

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, image defects were found to be caused by cutting powder, environmental foreign matter, etc. generated during the surface processing of the substrate, using cutting oil as a binder and using the cutting oil as a binder. Or the cutting oil itself is decomposed and firmly fixed, and furthermore, it is found that the cause is that the cutting oil itself is firmly fixed by a chemical reaction. By cutting with a cutting tool using a water-based cutting fluid instead of cutting oil, it has been found that image defects are reduced, subsequent cleaning is easy, and an electrophotographic photosensitive member suitable for reversal development is obtained. Thus, the present invention has been completed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming method in which spots and interference fringes (moire) do not occur. Another object of the present invention is to provide an image forming method in which stable potential characteristics are exhibited even when images are repeatedly formed, and the image quality is not deteriorated.

[0010]

According to the image forming method of the present invention, the surface of an electrophotographic photoreceptor base material is cut with a cutting tool while supplying an aqueous cutting fluid to the surface , and the surface roughness is zero. 0.3 to 2.0 μm Rmax , and
5 to 15 fines on the surface within 0.1 mm in length
An image is formed by a reversal development method using an electrophotographic photosensitive member having a photoconductive photosensitive layer provided on an electrophotographic photosensitive member substrate having "undulations" having small roughness . Further, the aqueous cutting fluid is a mixture of water and a surfactant or water and a water-soluble organic solvent .

[0011]

By using a water-based cutting fluid, welding and sticking of cutting foreign substances such as cutting powder, dust and dirt to the surface of the substrate can be effectively prevented. Even if the deposits are generated, they do not firmly adhere, so that the subsequent cleaning becomes easy.
Therefore, when applied to the reversal development method, it is possible to form an image without spots, spots, and partial fog. The electrophotographic photosensitive member substrate has a surface roughness of 0.3 to 2.0 μm.
Rmax der is, moreover on its surface, is 0.1mm or less in length
"Waviness" with 5 to 15 minute roughness on the inner part
Since it is present , the occurrence of interference fringes (moire) is effectively prevented when applied to an exposure process using a laser beam, such as a digital copier or a laser printer.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The electrophotographic photosensitive member used in the present invention has a surface roughness of 0.3 to 10 obtained by cutting the surface of an electrophotographic photosensitive member base material with a cutting tool while supplying an aqueous cutting fluid. 2.0 μm Rmax and the surface has a length
5 to 15 micro-roughness within 0.1 mm
This is an electrophotographic photosensitive member in which a photoconductive photosensitive layer is provided on an electrophotographic photosensitive member substrate having "undulations" .

As a material for the electrophotographic photosensitive member base material,
Aluminum-based materials are preferred. Specifically, A1070, A1100, A3003, A5005, A580 specified in JIS
5, A6063 or the like is used. The form of the base material is not particularly limited, and may be any of a rotary drum shape and an endless seat belt shape.

At the time of cutting, an aqueous cutting fluid is used. The supply of the aqueous cutting fluid to the surface of the base material is preferably performed in the form of a mist using, for example, a needle spray gun. By using the mist-like water-based cutting fluid, strong adherence of cutting powder and environmental foreign matter generated during cutting to the surface of the base material is effectively prevented, and the cutting powder and the like enter into the concave part having minute roughness. As well as easy to remove. Further, since the cutting powder does not firmly adhere to the surface of the base material, it is easy to clean. Therefore, there is little need to use Freon or a chlorine-based solvent, and there is no risk of causing environmental health problems. Even when such contact-type cleaning is applied, cleaning can be sufficiently performed with a small rubbing force, and there is no possibility that scratches that cause image defects may occur on the surface of the substrate.
Further, even if left for a long period of time, there is no possibility that cutting powder and environmental foreign substances will firmly adhere to the substrate surface. Furthermore, at the time of surface processing, since a uniform and durable oxide film is formed on the surface of the base material made of an aluminum-based material by the mist-like aqueous cutting fluid, the surface condition of the base material is stable and partial corrosion occurs. There is no fear.

The supply amount of the water-based cutting fluid has a good cooling action,
From the viewpoint of obtaining a lubricating action and a cleaning action, 0.003 ml /
cm ² or more. Specific examples of the water-based cutting fluid include pure water, tap water, anionic, cationic, nonionic, and amphoteric surfactant aqueous solutions, or alcohol-based and ketone-based solvents such as water-soluble organic solvents. An aqueous solution of a solvent may, for example, be mentioned. In the present invention, a mixed solution of water and a surfactant or a mixture of water and a water-soluble organic solvent is particularly preferred because excellent cleaning properties are exhibited.

As the cutting tool, a cutting tool made of a polycrystalline diamond sintered body is preferable. In roughing, a normal polycrystalline diamond sintered body is used, and in finishing,
It is preferable to use a cutting tool which is a polycrystalline diamond sintered body, has a grain size of about 0.5 μm, and has a nose radius R of 20 mm or more. By using a nose with a large radius R, the maximum height Rmax in the feed pitch of the cutting tool is reduced, and the machined surface is easily cleaned. That is, the maximum height Rmax is small and the pitch is large. Also, by increasing the radius R of the nose roundness, if the maximum height Rmax is the same, the feed pitch of the cutting tool can be increased, which is also effective for the tact time. Here, the maximum height Rmax is JIS B0601
-Measured according to 1982. The measuring instrument used was a stylus-type surface roughness measuring instrument “Surface roughness measuring instrument SE-30H” (manufactured by Kosaka Laboratories) specified in JIS B0651. The nominal value is 2 μm.

As conditions for surface processing, in roughing, the spindle speed is preferably 2000 to 6000 rpm, the depth of cut is about 0.1 to 0.2 mm, and the feed pitch is about 0.2 mm / rev.
It is preferable that the spindle speed is 2000 to 6000 rpm, the depth of cut is 20 μm, and the feed pitch is about 0.2 mm / rev. The spindle speed is
Since it differs depending on the outer diameter of the tubular base, it cannot be specified unconditionally.

In the present invention, the surface roughness of the base material is
The cutting is performed so as to obtain 0.3 to 2.0 μm Rmax. When the surface roughness is in such a range, the occurrence of interference fringes (moire) is effectively prevented when applied to an exposure process using a laser beam.

Furthermore, in the present invention, the surface of the cutting electrophotographic photoconductor substrate, there is a "waviness" which has 5 to 15 amino microroughness in part within 0.1mm length
It is necessary to. The presence of such “undulations” effectively prevents the occurrence of interference fringes (moire). Here, the fine roughness is measured in the same manner as the measurement of the maximum height Rmax described above, and the fineness of the fine roughness that can be measured varies depending on the radius of curvature of the tip of the stylus used. In one example, a stylus having a nominal radius of curvature of 2 μm is used.

The machine tool that can be used for processing the surface of the base material is not particularly limited. For example, there is a lathe for processing the base material shown in FIG. 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 bite. When the operator steps on the operating air valve 7, air is sent to the atomizer 4, and a cutting fluid, that is, a water mist is ejected from the ejection nozzle 5 of the cutting fluid container 6 to a contact portion between the cutting tool 8 and the base 1. You. As a specific example of a cutting fluid spraying device, "Magic Cut"
(Made by Fuso Seiki). FIG. 2 is an enlarged view of the cutting fluid spraying device.

The surface-treated substrate is then subjected to a cleaning step. Since the surface-treated substrate is easy to clean, it is easy to clean, and therefore, brush cleaning with a small rubbing force, ultrasonic cleaning, and pure water. Cutting powder and the like can be easily washed by washing or the like. Therefore, sticking of cutting powder and the like to the surface of the base is sufficiently prevented. The substrate that has passed through the washing step is then subjected to a drying step, and for example, steam or the like is used as the drying means.

The electroconductive photosensitive layer is formed by laminating a photoconductive photosensitive layer on the surface of the electrophotographic photosensitive member substrate whose surface has been processed as described above. As the 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 photosensitive member having the above-described structure. A conventionally known method can be adopted as the reversal development method.

Next, specific examples will be described, but the present invention is not limited to these examples. Example 1 The surface of the base material was cut with a cutting tool while supplying a cutting fluid to the surface of the base material under the following conditions. Next, the substrate was washed to obtain a surface-processed electrophotographic photosensitive member substrate having an outer diameter of 180 mm and a length of 350 mm. The surface roughness of this substrate was 1.0 μm Rmax, and the number of micro-roughness in a portion whose length was within 0.1 mm was 10. (1) Substrate A substrate made of an aluminum-based material and having an outer diameter of 60 mm
A rotary drum-shaped substrate made of A40S (6000 series) manufactured by Kobe Steel and having a length of 273 mm was used. (2) Cutting fluid Tap water having a specific resistance of 5 kΩ / cm was used. (3) The supply amount of the cutting fluid was supplied so as to be 0.003 ml / cm ² . (4) Machine tool The lathe for processing a substrate shown in FIG. 1 equipped with “Magic Cut” (manufactured by Fuso Seiki Co., Ltd.) as a spraying device for cutting fluid was used. (5) Tool Bit In the rough machining, a bit made of a polycrystalline diamond sintered body having a nose radius of 3 mm and a grain size of 5 μm was used. In the finishing, a tool made of a polycrystalline diamond sintered body having a nose radius of 20 mm and a grain size of 0.5 μm was used. (6) Machining conditions In rough machining, the spindle speed is 3000 rpm and the feed pitch is 0.2.
mm / rev and the depth of cut were 0.2 mm. In finishing, the spindle speed is 3000rpm, feed pitch is 0.2mm / rev, depth of cut is
It was 20 μm. (7) Cleaning conditions Ultrasonic cleaning was performed using 1,1,1-trichloroethane, and further brush scrubbing cleaning was performed.

Using the electrophotographic photosensitive member substrate obtained as described above, an intermediate layer, a charge generation layer, and a charge transport layer are sequentially laminated as follows to form a two-layer structure of a function separation type. An electrophotographic photosensitive member provided with an organic photosensitive layer was produced.

(1) Intermediate layer As a coating solvent, 9000 ml of toluene and 2-butanone (M
EK) 1000 ml and "ELVAX as a binder
An intermediate layer having a dry thickness of 0.4 μm was provided on the electrophotographic photosensitive member substrate using 30 g of “4260” (ethylene resin, manufactured by DuPont-Mitsui Polychemicals).

(2) Charge Generating Layer Using 10,000 ml of 2-butanone (MEK) as a coating solvent and 20 g of “KR-5240” (silicone resin, Shin-Etsu Chemical Co., Ltd.) as a binder (solution), And a charge generation layer having a thickness of 0.5 μm after drying was provided on the intermediate layer using 20 g of τ-type metal-free phthalocyanine. In addition, the coating liquid was prepared by dispersing with a sand grinder for 2 hours.

(3) Charge transport layer 10000 ml of 1,2-dichloroethane was used as a coating solvent, 2300 g of "Iupilon Z-200" (polycarbonate resin, manufactured by Mitsubishi Gas Chemical Company) was used as a binder, and the following charge transport material was used. Using 1400 g of the compound represented by No. 1, a charge transport layer having a thickness of 20 μm after drying was provided on the charge generation layer.

[0029]

Embedded image

The above electrophotographic photoreceptor was mounted on a digital multi-color copier "Konica 8028" (manufactured by Konica Corporation), and an actual photographing test for forming an image by a reversal development method was conducted at room temperature and normal humidity (20 ° C., 50 ± 10%). RH), high temperature and high humidity (33 ℃, 80 ±
10% RH) and low temperature and low humidity (10 ° C., 20 ± 10% RH), and the following items were evaluated. The copier employs PWM (pulse width modulation) with an intermediate gradation of 64 values and is equipped with a semiconductor laser light source as an exposure light source.

Evaluation Items (1) Evaluation of Potential Unexposure potential (V _H ) and exposure potential (V _L ) of the electrophotographic photosensitive member were examined at the initial stage and at 1000 copies. The charger used was a scorotron, and the grid potential was -60.
0 V was applied. (2) spots with (punctate stain) evaluation image analyzing apparatus "Ominikon 3000 form" (manufactured by Shimadzu Corporation) to measure the particle size and the number of spots, major axis is more Pochi 0.05 mm 1 cm ² per Judgment was made based on the number of pieces. The evaluation was evaluated as 個 when 0 / cm ² , Δ when 1 to 10 / cm ² , and × when 11 / cm ² or more. Note that ○ and Δ are practical levels. (3) Evaluation of interference fringes (moire) Observation was made on solid portions and halftone portions of the image. O: No moire was observed, Δ: Moire was slightly observed, X: Moire was clearly observed. did.

Examples 2 to 3 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the conditions shown in Table 1 below were used.

Comparative Examples 1 to 3 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the conditions shown in Table 1 below were used. The cutting fluid “D110” (manufactured by Esso) is a water-insoluble cutting fluid containing 54% of paraffinic hydrocarbons and 46% of 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]

As described in detail above, according to the image forming method of the present invention, an image can be formed without generating spots and interference fringes (moire), and the image is formed repeatedly. In this case, stable potential characteristics are exhibited,
Image quality does not decrease.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a lathe for processing a substrate.

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

[Explanation of symbols]

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

Continued on the front page (72) Inventor Toyoji Ito 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Nao Kawada 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Corporation (56) References JP-A-2-253268 (JP, A) JP-A-58-29898 (JP, A) JP-A-62-187800 (JP, A) JP-A-59-227991 (JP, A) JP-A-2-40663 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 5/00

Claims (2)

(57) [Claims] 1. A while supplying an aqueous cutting fluid to the electrophotographic photoreceptor substrate material surface of the obtained by cutting the surface by byte, the surface roughness 0.3~2.0μmRmax der
And the surface has a length of 5 to 1 mm within 0.1 mm.
An image is formed by a reversal development method using an electrophotographic photosensitive member in which a photoconductive photosensitive layer is provided on an electrophotographic photosensitive member substrate having five "undulations" having minute roughness. Image forming method. 2. An image forming method, wherein the aqueous cutting fluid according to claim 1 is a mixture of water and a surfactant or a mixture of water and a water-soluble organic solvent.