JPH02176690A - Electrophotographic copying device - Google Patents

Abstract

PURPOSE:To make oxidation-resistant action on the surface of an organic electrophotographic sensitive body excellent and to use a wide range of antioxidant by providing a means for supplying the antioxidant to the surface of the sensitive body. CONSTITUTION:The copying device is provided with a cleaning part 7 having a cleaning roller 10 or a cleaning blade 11 for removing toner remaining on the surface of the electrophotographic sensitive body and an optical static eliminating part 8 for eliminating the residual potential of the surface of the sensitive body 9. The antioxidant powder 12 is allowed to be applied to the surface of the sensitive body 9 through the part of the cleaning blade 11 or the cleaning roller 10 which the cleaner 7 has. Thus, a gas exhaust means is not needed and the oxidation-resistant action of the sensitive body of its own, especially the oxidation-resistant action on the surface of the sensitive body 9, becomes excellent. Therefore, the sensitive body is excellent in durability and a wide range of antioxidant is used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic apparatus, and more particularly to an electrophotographic apparatus having an organic electrophotographic photoreceptor and a means for supplying an antioxidant to the surface of the photoreceptor. Concerning photographic equipment.

[Conventional technology]

In a conventional electrophotographic apparatus, an electrophotographic photoreceptor undergoes a series of electrophotographic processes, namely: - secondary charging, formation of an electrostatic latent image by imagewise exposure, development with toner charged to the opposite polarity of the electrostatic image; It is used under repeated processes of transferring a toner image onto plain paper, removing residual toner on the drum using a cleaning device, and removing charges on the drum using strong vibration light.

Many efforts have been made to extend the durable life of a photoreceptor through repeated use, particularly its mechanical life. However, there are many factors other than mechanical durability that determine the life of a photoreceptor.

The photoreceptor is exposed to charging processes such as primary charging, transfer charging when the toner image on the photoreceptor after development is transferred to paper, and separation charging when separating the transfer paper from the photoreceptor. These charges are performed by corona discharge or by bringing a conductive rubber roller or the like into close contact with the photoreceptor. When these charges occur, oxygen and nitrogen in the air, ozone,
It is well known that nitrogen oxides and the like are generated and affect the life of the photosensitive drum. If ozone or nitrogen oxides affect the surface of the photosensitive drum, this can be dealt with by mechanically polishing the surface of the photosensitive drum.

However, some of these penetrate into the photosensitive layer and react with substances inside the photosensitive layer. Nitrogen oxides also react with water in the air to produce nitric acid, which accumulates in corona chargers and roller chargers during long-term use. This accumulated nitric acid moves from the charger onto the photosensitive drum when it is not used for a long time, and enters the inside of the photosensitive drum. The nitric acid that has entered reaches the interface between each layer of the photoreceptor and the substrate. For this reason, charge carriers are generated in the area where nitric acid has entered, and the state of charge injection from the substrate changes, resulting in increased sensitivity and charging ability, and traces of the area corresponding to the charger appear on the image. It appears as black spots or white spots in the image.

In order to prevent these phenomena, conventional methods have been used, for example, to exhaust air containing ozone and nitrogen oxides around the photosensitive drum to the outside of the electrophotographic device, or to remove air from the surface layer or all layers of the photosensitive drum. Measures have been taken to prevent the occurrence of image defects by adding additives such as antioxidants to capture and inactivate ozone, nitrogen oxides, nitric acid, etc. that have entered the photosensitive layer. .

[Problem to be solved by the invention]

However, the method of discharging contaminated gas outside the machine is not perfect, and it also affects the design of the machine, so it is not possible to provide a perfect countermeasure. In addition, when adding an antioxidant, the antioxidant is distributed throughout the added layer, so it is weak especially when used as an enemy on the surface, and it is difficult to reduce the resistance of the surface. Although the effect is recognized, it is not sufficient. When the amount of additives is increased to further enhance the effect, many of them cause deterioration of the electrophotographic It was often difficult to select a nitric acid scavenger or a nitric acid scavenger, or to use a combination of several types.

The present invention has an organic electrophotographic photoreceptor, and includes charging, image exposure,
In an electrophotographic apparatus for obtaining a copy image by a process including development, transfer, and cleaning steps,
It is an object of the present invention to provide an electrophotographic apparatus which does not require a gas exhaust means, has excellent oxidation resistance, especially oxidation resistance on the surface, and can use a wide variety of antioxidants.

[Failure to solve the problem]

In the present invention, the above object is achieved by using an antioxidant and improving the apparatus so that the antioxidant is constantly supplied to the surface of the photoreceptor.

That is, the present invention provides an electrophotographic apparatus having an organic electrophotographic photoreceptor photoreceptor and for obtaining a copied image by a process including charging, image exposure, development, transfer, and cleaning steps. It is characterized by having means for supplying an antioxidant to the surface of the photographic photoreceptor.

In the electrophotographic apparatus of the present invention, it is possible to constantly supply the powder of the ^2 inhibitor to the surface of the photoreceptor via, for example, a cleaning blade, a cleaning roller, or a web.

In the electrophotographic apparatus of the present invention, a wide variety of antioxidants can be used as the antioxidant, and among them, for example, the following substances are effective. In addition, in the following structural formula, - bonded to the benzene ring or heterocycle means a methyl group, and + means a t-butyl group.

Nee ／　＼ o.

(26) So Engineering 1 country CJ-(J-CJ λ λ The present invention will be specifically described below with reference to the drawings.

FIG. 1 is a schematic diagram of the vicinity of a photoreceptor of an electrophotographic apparatus to which the present invention is applied. 1 is a primary charging section for charging the surface of the photoreceptor 9 to θ; 2 is an image exposure section for forming an electrostatic latent image on the drum surface; 3 is a developing section for toner development; 4
is a transfer paper; 5 is a transfer section for transferring the developed toner image onto the transfer paper; 6 is a fixing section for fixing the transferred toner onto the transfer paper; 7 is a section for removing toner remaining on the surface of the photoreceptor. A cleaning section 8 equipped with a cleaning roller 10 or a cleaning blade 11 (FIGS. 2 to 4) is an optical charge eliminating section for removing residual potential on the surface of the photoreceptor. The present invention is a cleaner 7 of these.
A new web 15 (FIG. 4) is provided which contacts the surface of the photoreceptor through the cleaning blade 11 and cleaning roller 10 portion held by the camera, or between 7 and 8.
Antioxidant powder can be applied to the surface of the photoreceptor through this web.

As an example of improving the cleaning blade part, for example, as shown in FIG.
There is a method of applying it by lightly rubbing it onto the surface of the photoreceptor.

In the case of an apparatus having a cleaning roller, for example, as shown in FIG. The antioxidant powder 12 is supplied little by little to a cleaning roller 10, and the antioxidant powder is applied to the surface of the photoreceptor via the cleaning roller 10.

In the case of supplying via a web, for example, as shown in FIG. The antioxidant powder can be applied to the surface of the photoreceptor by coating the web and rubbing this web onto the surface of the photoreceptor. .

Although the antioxidant powder supply means using a cleaning blade, a cleaning roller, or a web has been described above, forms other than these can also be used at will, and the point is to select an appropriate form depending on the electrophotographic apparatus to which it is applied. should be adopted.

Next, examples will be shown in which the antioxidant is actually supplied to the photoreceptor using the three methods described above, and a comparative example in which the antioxidant is not used.

[Example 1] A 5% methanol solution of soluble 6/G 6/610/12 quaternary nylon resin was applied by dipping onto an aluminum cylinder support with a diameter of 80 mm and a length of 360 cm.
A micrometer-thick undercoat layer was provided.

Next, 10 parts of a pigment represented by the following structural formula (heavyweight, hereinafter the same), 8 parts of polyvinyl butyral resin, and 50 parts of cyclohexanone were dispersed for 20 hours in a sand mill apparatus using 1 size φ glass beads.

Add 70 to 120 methyl ethyl ketone (as appropriate) to this dispersion.
A charge generating layer having a thickness of 0.15 μm was formed by coating the undercoat layer on the undercoat layer.

Next, 10 parts of bisphenol 2 type polycarbonate and 10 M of a charge transport material represented by the following structural formula were dissolved in 80 parts of a 3:1 mixed solvent of monochlorobenzene and dichloromethane, and this solution was applied onto the charge generation layer. After coating using the dipping method, drying with hot air at 100℃ for 1 hour
A charge transport layer with a thickness of μm was formed.

This photoreceptor was installed in an electrophotographic copying machine of the type shown in FIG. 2, which had been modified to supply an antioxidant to the cleaning blade portion, and heated at 25°C.

A process of O corona charging at 55% RH, image exposure, and full-surface exposure is used, but one sheet is subjected to durability without toner development or transfer, and then an image is formed using a normal electrophotographic process. However, the image was K.
An image in good condition with no blemishes or blemishes was obtained. Furthermore, this was attached to the machine and left for 12 hours, and then the image quality test was performed again, and the same good image as before being left was obtained.

Next, a photoreceptor prepared in the same manner was subjected to the same process of θ corona charging, image exposure, and full exposure without adding any antioxidant, but one sheet was subjected to durability without toner development or transfer. After that, when I quantified the image,
There were scratches on the image, and the sharpness was significantly reduced. Ota 1
In the image after being left for 2 hours, the area under the charger was seen as a white band.

The antioxidant used here has the structure shown below.

CH.

[Example 2] A 5% methanol solution of soluble 6/66/610/12 quaternary nylon resin was applied by dipping onto an aluminum cylinder support with a bow diameter of 360 mm and a thickness of 1 μm.
A thick undercoat layer was provided.

Next, 12 parts of a pyrazoline compound having the following structural formula and io parts of bisphenol A polycarbonate were dissolved in 88 parts of a 1:3 mixed solvent of dioxane and dichloromethane. This solution was dip-coated onto the undercoat layer and heated to 100°C.
A charge transport layer having a thickness of 19 μm was formed by drying with hot air for a period of time.

Next, add 10 parts of bisazo pigment represented by the following formula to bisphenol type 2? Similar results were obtained when the method was evaluated using monochrome charging using recarbonate, and better images could be stably obtained when an antioxidant was added. The antioxidant used here has the structural formula shown below.

It was added to 100 parts of a solution (weight concentration 2%) dissolved in a mixed solvent of rubenzene/dichloromethane = 3/1, and the mixed solution was dispersed in a stainless steel sol mill for 50 hours. This dispersion was applied onto the charge generation layer and dried at 100° C. for 20 minutes to form a charge generation layer with a thickness of 3 μm. Two of these photoreceptors were produced. - The book was installed in an electrophotographic copying machine modified to supply antioxidant to the surface of the photoreceptor using a web of the type shown in Figure 4, and the other book was installed in an unimproved original copying machine. Attach it to your copy machine,
In the evaluation method of Example 1, e-charging was performed using ■ [Example 3] An aluminum cylinder with outer diameter of 80 mm x 360 mm was used as a support, and 5% of 6/66/610/12 quaternary soluble nylon was applied to it. A 1 μm thick subbing layer was provided by dip coating a methanol solution.

Next, 1 part of aluminolide phthalocyanine and 10 parts of bisphenol type 2 polycarbonate were added to a mixed solvent of 40 parts of monochlorobenzene and 10 parts of dichloromethane.
The mixture was dispersed in a stainless steel sol mill for 50 hours, and 7 parts of a hydrazone compound having the structure shown below was further dissolved therein.

The thus prepared dispersion was dip coated onto the undercoat layer to form a 20 μm thick photosensitive layer.

Two photoreceptors were made.

One of these two photoreceptors is operated using a process of θ corona charging, image exposure and full exposure, but without toner development or transfer, and is operated for the equivalent of 100 sheets.
Thereafter, images were taken under normal conditions.

Next, the remaining one was attached to a trap by modifying the copying machine so that antioxidant could be supplied to the surface of the photoreceptor using a cleaning roller of the type shown in Figure 3.
After running for 00 sheets, images were produced under normal conditions.

The antioxidant used here has the following structural formula (% formula). Images obtained using a machine without modification lacked sharpness and had low resolution.

On the other hand, images obtained using a machine that was modified so that antioxidant was constantly supplied to the surface of the photoreceptor had high resolution and sharpness.

〔Effect of the invention〕

The electrophotographic apparatus of the present invention does not require a gas exhaust means,
The photoreceptor itself has excellent oxidation resistance, particularly the oxidation resistance on the surface of the photoreceptor, and therefore has excellent durability, and a wide variety of antioxidants can be used.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the vicinity of a photoreceptor of an electrophotographic apparatus. FIG. 2 is a schematic diagram illustrating a supplying means for supplying antioxidant powder using a cleaning blade portion. FIG. 3 is a schematic diagram illustrating a supply means in the case of supplying antioxidant powder using a part of the cleaning roller. FIG. 4 is a schematic diagram illustrating a supply means for supplying antioxidant powder via a web. In the figure, 1 is the primary charging section, 2 is the image exposure section, 3 is the developing section, and 4 is the primary charging section.
1 is a transfer paper, 5 is a transfer section, 6 is a fixing section, 7 is a cleaning section, 8 is an optical static elimination section, 9 is a photoreceptor, 10 is a cleaning roller, 11 is a cleaning blade, 12 is an antioxidant powder, 13 is a powder press 14 is a blade, 14 is an antioxidant powder supply roller, 15 is a web, 16 is a web supply section, and 17 is a web winding section. 2nd

Claims (2)

[Claims] (1) In an electrophotographic apparatus that has an organic electrophotographic photoreceptor and obtains a copied image by a process including charging, image exposure, development, transfer, and cleaning steps, the surface of the organic electrophotographic photoreceptor is An electrophotographic apparatus characterized in that it has means for supplying an antioxidant. (2) The electrophotographic apparatus according to claim 1, wherein the means for supplying the antioxidant includes a cleaning blade, a cleaning roller, or a web as a part thereof.