JPH0944032A - Recyclable cylindrical parts for electrophotographic process - Google Patents

Abstract

(57) [Abstract] [Purpose] A recyclable electrophotographic cylindrical part capable of separating a coating film from a cylindrical base material easily and efficiently at low cost and repeatedly using the cylindrical base material. To provide. [Structure] In a photosensitive drum, a charging roller or a developing sleeve (a cylindrical part for an electrophotographic process), a cylindrical base material 1 and a photoreceptor layer, a charging elastic layer or a conductive coating layer (coating film) formed on the outer surface of the cylindrical base material 1. The intermediate layer 2 having a coefficient of thermal expansion larger than that of the cylindrical substrate 1 is formed between the intermediate layer 2 and the intermediate layer 3. According to the present invention, the intermediate layer 2 and the photoreceptor layer, the charging elastic layer, or the conductive coating layer (coating film) formed on the intermediate layer 2 due to the difference in the thermal expansion amount only by heating the photosensitive drum, the charging roller or the developing sleeve. 3 is easy and efficient, and
It can be separated and removed from the cylindrical base material 1 at low cost, and the photosensitive material drum, the charging roller or the developing sleeve can be reprocessed by repeatedly using the cylindrical base material 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducible electrophotographic process part such as a photosensitive drum, a charging roller and a developing sleeve which are mainly used in image forming apparatuses such as copying machines and laser beam printers.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a laser beam printer, an image is formed by using a so-called electrophotographic process. That is, after a positive or negative charge is charged on the photosensitive drum by the primary charger, the photosensitive drum is irradiated with light such as a laser beam to draw an image on the photosensitive drum. Then, the electric charge disappears in the light-irradiated portion of the photosensitive drum, and the electric charge remains in the light-irradiated portion. As a result, a potential difference corresponding to the shape of the image is generated on the photosensitive drum, and an electrostatic latent image is formed on the photosensitive drum.

Then, the electrostatic latent image is developed by a developing device to be visualized. That is, in the developing device, the toner charged with an electric charge opposite to the electric charge on the photosensitive drum is attached to the electrostatic latent image via the developing sleeve, whereby the electrostatic latent image is developed and visualized as a toner image. . Next, this toner image is transferred onto a transfer material such as paper, and the transfer material onto which the toner image has been transferred is conveyed to a fixing device, where the toner image is fixed by heat and pressure, and finally discharged outside the machine. It

By the way, in recent years, with the downsizing and personalization of such an image forming apparatus, a charging device, a photosensitive drum, a developing device, and the like are integrated into a cartridge to facilitate replacement during maintenance. Therefore, the cartridge is a consumable item that is regularly replaced and discarded.

[0007] Thus, there are a charger using a corona discharge and a roller charger as the charger constituting the cartridge. The roller charger charges the surface of the metal cored bar 10 ⁶
It is composed by covering with an elastic body having a resistance of about 10 ⁷ Ωcm, which forms a charge on the surface by a bias power source and contacts it with the photosensitive drum to uniformly charge the photosensitive drum. It is applied to charge the photosensitive drum.

The photosensitive drum is roughened by roughening the outer surface of the aluminum drum to a thickness of 0.1 to 20.
It is manufactured by fixing an inorganic or organic photoreceptor of 0 μm. In the production of this photosensitive drum, defective products related to the photoconductor occur at a rate of about 5%, but the aluminum drum, which is a cylindrical base material, is not reused and all defective products are discarded. . Further, in this type of photosensitive drum, when the photosensitive member deteriorates due to use, the aluminum drum, which is a cylindrical base material, is discarded without being reused.

Further, the developing sleeve having the function of adhering the toner to the photosensitive drum is constituted by forming a conductive layer made of carbon and graphite on the surface of a metallic cylindrical base material.

[0008]

By the way, conventionally, the photosensitive drum, the charging roller and the developing sleeve, which are the main parts constituting the cartridge, may be discarded together with the cartridge when the cartridge reaches the end of its life and is discarded. There were many.

However, in recent years, from the viewpoint of resource saving and environmental protection, it has been proposed to reuse the photosensitive drum, the charging roller and the like. Specifically, for example, the photoconductor layer and the conductive coat layer formed on the outer peripheral surface of the aluminum drum, which is the cylindrical substrate of the photosensitive drum or the developing sleeve, are removed, and the aluminum drum is reused as the substrate. A method has been proposed.

Here, the reuse of the photosensitive drum will be described as an example.

When the photosensitive drum is reused, it is necessary to completely remove the photosensitive layer formed on the outer surface of the aluminum drum which is the cylindrical base material. As a method of removing the photoconductor layer, a method of peeling the photoconductor layer with a brush or a cutter can be considered, but in the method of removing all the photoconductor layers with a brush or a cutter, the peeling efficiency of the photoconductor layer is improved. However, there is a problem that the outer surface of the aluminum drum is easily scratched, and mechanical refinishing of the outer surface of the drum is required.

On the other hand, instead of the mechanical method for removing the photoconductor layer, the photoconductor layer can be removed with an organic solvent. However, the method using an organic solvent has a problem in that the solvent is flammable and thus requires careful handling. In addition, since a large amount of solvent is required for cleaning and a separate water distribution treatment facility is required, there is a problem that the cost of regenerating the photosensitive drum is significantly increased.

The present invention has been made in view of the above problems, and an object of the present invention is to easily and efficiently separate a coating film from a cylindrical base material at a low cost to repeat the cylindrical base material. The object is to provide a recyclable cylindrical part for electrophotographic processes which can be used.

[0014]

In order to achieve the above object, the invention according to claim 1 is, in a cylindrical part for electrophotographic process, between a cylindrical base material and a film formed on the outer surface thereof. The intermediate layer having a coefficient of thermal expansion larger than that of the cylindrical substrate is formed.

According to a second aspect of the invention, in the first aspect of the invention, the material of the intermediate layer is zinc, lithium,
It is characterized by using selenium, indium or cesium.

A third aspect of the invention is characterized in that, in the first aspect of the invention, the film is a photosensitive layer of a photosensitive drum.

A fourth aspect of the invention is characterized in that, in the first aspect of the invention, the coating is a charging elastic layer of a charging roller.

A fifth aspect of the invention is characterized in that, in the first aspect of the invention, the film is a conductive coat layer of a developing sleeve.

Therefore, according to the present invention, the intermediate layer and the coating film formed thereon can be easily and efficiently produced at low cost by heating the cylindrical part for electrophotographic process due to the difference in thermal expansion amount. The cylindrical substrate with the coating removed can be repeatedly used to reprocess the cylindrical part for the electrophotographic process.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a partial perspective view showing a cross section of a part of the reproducible photosensitive drum, charging roller or developing sleeve according to the present invention. The photosensitive drum, the charging roller or the developing sleeve is a cylindrical substrate 1 made of aluminum or the like.
And the intermediate layer 2 which is the main member of the present invention formed on the outer peripheral surface of the cylindrical base material 1, the photosensitive layer 3 (in the case of a photosensitive drum) formed on the outer peripheral surface of the intermediate layer 2, and the charging elasticity. Layer 3 (in the case of a charging roller) or conductive coat layer 3 (in the case of a developing sleeve) constitutes a three-layer structure. A journal shaft portion 1a is integrally formed at both ends of the cylindrical base material 1 (see FIG. 3).

The intermediate layer 2 is made of a material having a coefficient of thermal expansion larger than that of the cylindrical substrate 1. For example, when the cylindrical substrate 1 is made of aluminum, the intermediate layer 2 is made of zinc, lithium, selenium, indium or cesium having a coefficient of thermal expansion larger than that of aluminum. The following table shows the linear expansion coefficient [10 ^-4 deg ^-1 ] of aluminum, zinc, lithium, selenium, indium and cesium.

[0023]

[Table 1] Next, a method of manufacturing the photosensitive drum, the charging roller, or the developing sleeve having the above structure will be described.

FIG. 2 is a perspective view of the cylindrical base material 1 made of aluminum or the like. When manufacturing a photosensitive drum, a charging roller or a developing sleeve, as shown in FIG. The intermediate layer 2 is formed by insertion, electrodeposition, vapor deposition or the like.

Next, the photosensitive layer 3 is formed on the intermediate layer 2 in the case of a photosensitive drum by dipping or the like, the charging elastic layer 3 is formed in the case of a charging roller, and the conductive layer is formed in the case of a developing sleeve. By forming the coat layer 3, the photosensitive drum, charging roller or developing sleeve shown in FIG. 1 can be obtained.

By the way, the photosensitive drum, the charging roller or the developing sleeve obtained as described above can be regenerated, and when they reach the end of their life, they are regenerated and the cylindrical substrate 1 is repeatedly used. used. The reproduction process is performed as follows.

That is, when the photosensitive drum, the charging roller or the developing sleeve is put into an electric furnace and heated to a high temperature, the coefficient of thermal expansion of the intermediate layer 2 is higher than that of the cylindrical substrate 1 as described above. Therefore, the amount of thermal expansion of the intermediate layer 2 is larger than that of the cylindrical substrate 1, and as shown in FIG. 4, the intermediate layer 2 and the photosensitive layer 3 (photosensitive layer formed on the outer periphery thereof) In case of drum), charging elastic layer 3 (in case of charging roller)
Alternatively, a gap δ is generated between the conductive coat layer 3 (in the case of a developing sleeve) and the cylindrical base material 1, and therefore, by merely tapping the end of the cylindrical base material 1 with the hammer 4 in the axial direction. The intermediate layer 2 and the photosensitive layer 3 (in the case of a photosensitive drum), the charging elastic layer 3 (in the case of a charging roller) or the conductive coat layer 3 (in the case of a developing sleeve) formed on the intermediate layer 2 are integrally formed into a cylindrical base material. Can be separated from 1. Then, a new intermediate layer 2 is formed on the outer peripheral surface of the remaining cylindrical substrate 1 by the method described above.
(See FIG. 3) on which the photoconductor layer 3 (in the case of a photosensitive drum), the charging elastic layer 3 (in the case of a charging roller) or the conductive coat layer 3 (in the case of a developing sleeve) is formed. The photosensitive drum, the charging roller or the developing sleeve can be regenerated, and the cylindrical substrate 1 can be repeatedly used without being discarded.

As described above, according to the present embodiment, the intermediate layer 2 and the photoconductor layer 3 formed on the intermediate layer 2 (due to the difference in the amount of thermal expansion only by heating the photosensitive drum, the charging roller or the developing sleeve). The photosensitive drum), the charging elastic layer 3 (in the case of a charging roller) or the conductive coat layer 3 (in the case of a developing sleeve) can be easily and efficiently used at a low cost without damaging the cylindrical substrate 1. The base material 1 can be separated and removed, and the photosensitive material drum, charging roller or developing sleeve can be recycled by repeatedly using the cylindrical base material 1.

[0029]

As is apparent from the above description, according to the present invention, in the cylindrical part for electrophotographic process, the cylindrical base material is provided between the cylindrical base material and the coating formed on the outer surface thereof. Since the intermediate layer having a coefficient of thermal expansion larger than that of the material is formed, the intermediate layer and the coating film formed thereon can be easily formed by heating the cylindrical part for electrophotographic process due to the difference in thermal expansion amount. The effect that it can be removed efficiently from the cylindrical base material at low cost, and the cylindrical base material with the coating removed can be repeatedly used to recycle the cylindrical part for electrophotographic process. Is obtained.

[Brief description of drawings]

FIG. 1 is a partial perspective view showing a part of a reproducible cylindrical member for electrophotographic process (photosensitive drum, charging roller or developing sleeve) according to the present invention in cross section.

FIG. 2 is a perspective view of a cylindrical substrate.

FIG. 3 is a partial perspective view showing a cross section of a part of a cylindrical base material formed by forming an intermediate layer on the outer peripheral surface.

FIG. 4 is a cross-sectional view showing a method of separating an intermediate layer and a coating formed thereon from a cylindrical substrate.

[Explanation of symbols]

1 Cylindrical substrate 2 Intermediate layer 3 Coating (photoreceptor layer, charging elastic layer, conductive coat layer)

Claims (5)

[Claims] 1. An intermediate layer having a coefficient of thermal expansion larger than that of the cylindrical base material is formed between the cylindrical base material and the coating formed on the outer surface of the cylindrical base material. Recyclable cylindrical parts for electrophotographic process. 2. The recyclable cylindrical part for electrophotographic process according to claim 1, wherein zinc, lithium, selenium, indium or cesium is used as a material of the intermediate layer. 3. The recyclable cylindrical part for electrophotographic process according to claim 1, wherein the coating is a photosensitive layer of a photosensitive drum. 4. The recyclable cylindrical part for electrophotographic process according to claim 1, wherein the coating is a charging elastic layer of a charging roller. 5. The recyclable cylindrical part for electrophotographic process according to claim 1, wherein the coating is a conductive coating layer of a developing sleeve.