JPH06195011A - Cleaning member for electrophotography and electrophotographic device using it - Google Patents

Abstract

PURPOSE:To rapidly remove release agent adhering to a transfer drum, a transfer belt, etc., or the release agent adhering to a photosensitive drum, a photosensitive sheet, etc., by forming a cleaning member by using particles absorbing the release agent. CONSTITUTION:In a transfer material carrying sheet cleaner 11; a fur brush cleaner 11a is disposed outside a transfer material carrying sheet 5f stretched on the peripheral surface aperture part of a cylinder 5a, and a backup brush 11b is disposed inside. Furthermore, a web cleaner 20 removing transferred release agent is provided on an upstream part in the traveling direction of the transfer drum. The web of the web cleaner 20 is obtained by adjusting colloidal liquid whose 5 pts. is constituted of alumina sol and 95 pts. is constituted of water and whose solid part is about 5%, immersing the web in the liquid till entire surface of nonwoven fabric is wet, drying, and cutting it. Consequently, since the particle surface of the web is fine porous, capillarity caused by the porousness makes the release agent rapidly absorbed inside the particles, so that the release agent is more rapidly removed than a conventional sponge.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for removing a photoconductor of an electrophotographic apparatus, a transfer material carrying member, a member on a conveying path, and a releasing agent attached and remaining on the transfer material after fixing. The present invention relates to a cleaning member and an electrophotographic apparatus using the cleaning member.

[0002]

2. Description of the Related Art Conventionally, the toner image on the image carrier is transferred to the transfer medium by facing the image carrier such as a photoconductor or an insulator having a toner image once or a plurality of times.
A large number of various electrophotographic apparatuses such as electrophotographic copying machines and printers for obtaining black and white or color images have been proposed and are commercially available. In such an electrophotographic apparatus, an image carrier, a transfer material carrying member such as a transfer drum and a member on a conveyance path, and a cleaning member for removing silicone oil remaining on the transfer material after fixing are not provided. For example, as in the cleaning article for an electrophotographic photosensitive member described in JP-A-55-166672, the cloth-like member is made by impregnating a cloth material with an abrasive dispersed in a solvent.

FIG. 2 shows an example of a color electrophotographic copying machine for forming a full-color image. In the figure, in a color electrophotographic copying machine, a drum-shaped electrophotographic photosensitive member which is an image bearing member, that is, a photosensitive drum 1 is rotatably supported in a direction of an arrow, and a corona charger 2 and an exposure unit are provided around the photosensitive drum 1. An optical system 3, a developing device 4, a transfer device 5, and a cleaner 6 are arranged.

The optical system 3 is composed of an original scanning section 3a and a color separation filter 3b, and irradiates a photosensitive drum 1 uniformly charged by a charger 2 with an optical image for each separated color image to form a latent image. Form. The developing device 4 in the form of a rotary developing device is provided with four developing devices around the central axis 4b, that is, a yellow developing device 4Y, a magenta developing device 4M, a cyan developing device 4C, and a black developing device 4B. Of the photosensitive drum 1 by rotating the developing device to the developing position facing the photosensitive drum 1.
The upper latent image is developed to form a toner image on the photosensitive drum 1.

Further, the toner image formed on the photosensitive drum 1 is transferred to the transfer material supplied from the transfer material cassette 7 via the transport system and the transfer device 5 to the position facing the photosensitive drum 1. The transfer device 5 includes a cylinder 5a, a transfer charger 5b, and a transfer material gripper 5 that grips and conveys the transfer material.
c, an inner charging device 5d, and an outer charging device 5e, and a transfer material carrying sheet 5f made of a dielectric material is stretched in a cylindrical shape in the circumferential opening area of the cylinder 5a.

As the transfer drum 5, which is a drum-shaped transfer device as described above, rotates, the toner image on the photosensitive drum 1 is transferred to the transfer material carrying sheet 5 by the transfer material charger 5b.
The transfer material is transferred onto the transfer material carried by f, and at the same time, the transfer material is adsorbed by the transfer material carrying sheet 5f. The photosensitive drum 1 is
After the residual toner is removed by the cleaner 6, the next image forming process is continuously performed.

In this way, a desired number of color images are transferred to the transfer material that is attracted and conveyed to the transfer material carrying sheet 5f, and a full color image is formed. Since such a color image forming method is well known to those skilled in the art, further description is omitted.

When the transfer of the four color toner images is completed in this way, the transfer material is separated from the transfer drum 5 and discharged onto the tray 10 via the heat roller fixing device 9.

As described above, in the color electrophotographic copying machine, the transfer material carrier for holding the transfer material, that is, the transfer material carrier sheet 5f made of a dielectric material is provided in the peripheral opening of the transfer drum 5. Although it is stretched, the photosensitive drum 1, the developing device 4, and the cleaner 6 are provided near the peripheral surface of the transfer drum 5.
A unit group that holds or stores a developer (toner) such as the above is arranged, and the unwanted toner scattered from these unit groups adheres to the transfer material carrying sheet on the transfer drum 5 to stain it. Sometimes. Furthermore,
Even when the transfer material on which the toner image has been transferred but not yet fixed is separated from the transfer drum 5, when the transfer material becomes a jam (the transfer material is jammed in the machine), Toner on the transfer material adheres to the transfer material-carrying sheet, and the transfer material-carrying sheet 5f is heavily soiled by the toner.

Therefore, the transfer device 5 is provided with a transfer material carrying sheet cleaner, that is, a cleaning means 11 for the purpose of removing the toner adhering to the transfer material carrying sheet 5f. Cleaning of the transfer material carrying sheet 5f is usually performed at the time of pre-rotation of the transfer drum 5 performed prior to transfer, but as described above, it is performed at any time after the transfer material is jammed or the like.

The transfer material carrying sheet cleaner 11 is shown in FIG.
As shown in FIG. 3, the fur brush cleaner 1 is provided outside the transfer material carrying sheet 5f stretched at the peripheral opening of the cylinder 5a which is a cylindrical transfer material carrying sheet supporting means.
1a and a backup brush 11b inside.

[0012]

However, in the above-mentioned conventional example, when the fixed image is fed again to form a so-called double-sided image, a releasing agent such as silicone oil attached to the paper after fixing causes There is a drawback that the toner adheres to the paper feed roller, the paper transport unit, the transfer drum, and the photosensitive drum to hinder the image forming process. In particular, when silicone oil adheres to the photosensitive drum, a phenomenon called oil fog occurs. The mechanism will be described with reference to FIGS.

FIG. 3 shows a state in which a part of the silicone oil existing on the fixed toner is transferred to the transfer drum.

FIG. 4 shows a state in which the transferred silicone oil existing on the transfer drum is transferred to the photosensitive drum via the nip at the time of post-rotation.

FIG. 5 shows a state in which the transferred silicone oil reaching the photosensitive drum adheres the toner existing around the photosensitive drum and transfers the toner at the time of the next transfer to cause a phenomenon called fogging.

In order to prevent such a problem,
It is necessary to quickly remove the transferred silicone oil.

However, a cloth-like member in which the above-mentioned abrasive is dispersed and impregnated in a solvent, or a cloth-like member simply made of a non-woven fabric does not have the ability to remove the transferred oil, so the oil is applied to the surface thinly. Will result.

Fur brushes cannot remove silicone oil.

[0019]

The cleaning member according to the present invention has particles that absorb a release agent.
The release agent adhering to the transfer material carrying member such as the transfer drum or the transfer bell or the release agent adhering to the photoconductor such as the photosensitive drum or the photosensitive sheet is quickly absorbed by the particles carried on the cleaning member. It can be removed. That is, the surface of the particles is finely porous, and the release agent is removed more quickly than, for example, a sponge by the rapid absorption of the release agent into the particles due to the capillary action of the porosity. To be done.

Porous particles are suitable as the particles for absorbing the release agent carried by the cleaning member of the present invention. Colloidal metal oxides such as colloidal alumina, colloidal silica, colloidal titania, and colloidal zirconia are used as such porous particles. These colloidal particles are made into a sol state using water or an organic solvent as a dispersion medium, and the sol is applied to a member such as a cloth, roll, or blade and dried to become colloidal particles, and a cleaning member is obtained. The colloidal particles are porous such as alumina hydrate and silica hydrate, unlike alumina and silica formed by firing.
Colloidal alumina is particularly suitable as such colloidal particles. Colloidal alumina is an alumina hydrate and is supported by impregnating a cloth-like member with a colloidal solution of alumina hydrate with water as a dispersion medium, which can remarkably enhance the release agent absorbing ability, and It can absorb the release agent. Therefore, the transferred oil can be quickly removed.

The colloidal solution of alumina hydrate using water as a dispersion medium is preferably boehmite-based alumina sol.

The release agent is a component applied to the rotating body in order to prevent the toner from adhering to the rotating body when the toner image is heated and pressed and fixed by the rotating body. Oils such as silicone oil, ester oil, liquid polyether, spindle oil, machine oil, and cylinder oil are used. The release agent may be contained in the toner particles and supplied in addition to being supplied from the oil tank to the rotating body.

The cleaning member is arranged at a place where the release agent can be removed. Generally, a cleaning member is disposed in contact with a transfer material carrying member such as a transfer drum and a transfer belt, a photosensitive member such as a photosensitive drum and a photosensitive sheet, or both of them.

[0024]

【Example】

(Embodiment 1) FIG. 1 shows an electrophotographic apparatus provided with a cleaning member according to an embodiment of the present invention. The construction and operation of this electrophotographic apparatus are substantially the same as those shown in FIG. 2 except for the cleaning member, and the description of common parts will be omitted.

In FIG. 1, a transfer drum 5 is a transfer material carrying sheet supporting means which is cylindrical in this embodiment, that is, a cylinder 5a, a transfer charger 5b, a transfer material gripper 5c which grips and conveys the transfer material, It has an inner charging device 5d and an outer charging device 5e, and a transfer material carrier (a sheet-shaped transfer material carrying sheet in this embodiment) 5f of a dielectric material is stretched in the peripheral opening area of the cylinder 5a. It constitutes a transfer device.

The transfer drum 5 is further provided with a transfer material carrying sheet cleaner (cleaning means) 11 for the purpose of removing the toner adhering to the transfer material carrying sheet 5f.

The transfer material-carrying sheet is usually cleaned during the pre-rotation prior to the transfer, but when the transfer material causes a jam or the like, the cleaning is carried out at any time.

The transfer material carrying sheet cleaner 11 comprises a transfer material carrying sheet 5 stretched over the peripheral opening of the cylinder 5a.
A fur brush cleaner 11a is provided outside f and a backup brush 11b is provided inside.

Further, with the above configuration alone, the oil is transferred during double-sided copying as described above. Therefore, the web cleaner 20 is provided upstream of the transfer drum in the running direction to remove the transferred oil.

The web used for the web cleaner 20 was prepared by the following method.

Alumina sol (Catalyst Kasei, trade name "AS
-3 ″) 5 parts (solid content) and 95 parts of water were prepared to a colloidal solution having a solid content of about 5%, and a non-woven fabric WP-80
Immerse 85 (made by Japan Vilene) until the entire surface gets wet,
After drying, it was cut to obtain a web.

The obtained web was evaluated by the following method. Canon color copier (trade name "CL
C-500 ") and silicone oil used for fixing (manufactured by Shin-Etsu Chemical Co., Ltd., trade name" KF-96 ", viscosity 300)
The oil application amount of cs) is adjusted to 0.08 g per A4 paper. As the coating amount, 50 sheets of blank paper are passed, and the amount of silicone oil retained per sheet at that time is used.

Next, an image is formed using a single color or a plurality of colors so that the amount of toner adhered is 1.5 g / A4, and the image is inverted.
The image is subjected to continuous 5-sheet double-sided image formation with an arbitrary image, and the process is completed.
After that, one blank sheet is passed through, for example, A3, and when the toner density is low and is set to 0, it is evaluated whether or not the toner of the first color is mainly transferred to the blank sheet. The toner spikes existing in the sleeve of the developing device are transferred because the transfer oil is present on the photosensitive drum, even though the bias is not applied, and the transferred toner has an electric charge. Will be done. Therefore, if there is transfer oil, fogging occurs on a blank sheet, and it can be determined whether the silicone oil has been removed.

The reason why the toner of the first color is mainly transferred is that if the toner of the first color further adheres to the oil, it exists like a spacer, and the toners of the second and subsequent colors become difficult to adhere.

With respect to the fog amount, it can be visually recognized with a Macbeth densitometer of 0.10 or more, so this value was used as a judgment standard.

Silicone oil could be removed from the web produced.

Example 2 A web was obtained in the same manner as in Example 1 except that Aluminasol 100 (trade name: manufactured by Nissan Kagaku) was used in place of Aluminasol AS-3.

The silicone oil could be removed from the web produced.

Example 3 In the immersion liquid prepared in Example 1, polyvinyl alcohol (trade name: PVA117K, manufactured by Kuraray Co., Ltd.) previously dissolved in water at 97 ° C. or higher was added to a solid content (colloidal alumina) of 7%. It is charged so that it dissolves with a stirrer at 70 to 100 rpm. The web is dipped while keeping the dipping solution at 85 ° C or higher.

A web was obtained in the same manner as in Example 1 except for the above.

Silicone oil could be removed from the web produced.

The web thus prepared may be sprinkled in a roll shape or may be sprinkled around the outer circumference of an elastic roll.

As the cloth-like member, it is particularly advantageous to use a non-woven fabric because there is no danger of damaging the member to be cleaned. However, it is also possible to use a soft gauze-like woven fabric.

Although the web cleaner 20 is provided on the transfer drum in this embodiment, it may be provided downstream of the cleaner of the photosensitive drum with respect to the running direction of the drum.

Further, the fixing mechanism may be provided after the fixing mechanism so that the fixed image and the silicone oil on the transfer material can be removed.

Further, the silicone oil may be removed by being provided on the paper feeding / transporting path.

In this example, in order to enhance the adsorption of alumina sol on the non-woven fabric, a non-woven fabric composed of ultrafine fibers (about 2 μ) was used.

(Example 4) In Example 1, instead of the alumina sol, silica gel having a solid content of 30% by weight (trade name: Cataloid SI-350, manufactured by Catalyst Kasei Co., Ltd.) was applied to a nonwoven fabric and dried to obtain a cleaning web. Got When this web was used as in Example 1, the silicone oil could be removed. When a finger was touched on the created web, white silica gel powder adhered to the finger.

[0049]

As described above, by forming a cleaning member using particles that absorb a release agent,
The release agent can be removed instantly.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an electrophotographic apparatus including a cleaning member according to an exemplary embodiment of the present invention.

FIG. 2 is a schematic sectional view of an electrophotographic apparatus provided with a conventional cleaning member.

FIG. 3 is an explanatory diagram of a mechanism in which a release agent transfers from a transfer material to a transfer drum during double-sided transfer in the apparatus of FIG.

FIG. 4 is an explanatory diagram of a mechanism in which a release agent is transferred from a transfer drum to a photosensitive drum when the transfer drum is rotated rearward in the apparatus of FIG.

5 is an explanatory diagram of a mechanism in which the adhered toner is transferred to a transfer material at the time of the next transfer in the apparatus of FIG.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuo Takeuchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masahiro Inoue 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (13)

[Claims] 1. A cleaning member for an electrophotographic apparatus, which comprises particles that absorb a release agent. 2. The cleaning member for an electrophotographic apparatus according to claim 1, wherein particles that absorb the release agent are carried on the cloth-like member. 3. The cleaning member for an electrophotographic apparatus according to claim 1, wherein the particles absorbing the release agent are colloidal alumina. 4. The cleaning member for an electrophotographic apparatus according to claim 3, wherein the colloidal alumina is a boehmite-based alumina sol. 5. An electrophotographic apparatus equipped with a fixing device for fixing a developer image transferred on a transfer material by a fixing rotator provided with a releasing agent, wherein particles absorbing the release agent are An electrophotographic apparatus comprising a cleaning member having the same. 6. The electrophotographic apparatus according to claim 5, wherein the cleaning member has a cloth-like member carrying particles that absorb a release agent. 7. The electrophotographic apparatus according to claim 5, wherein the particles absorbing the release agent are colloidal alumina. 8. The electrophotographic apparatus according to claim 5, wherein the colloidal alumina is a boehmite-based alumina sol. 9. The electrophotographic apparatus according to claim 5, wherein the cleaning member is disposed in contact with the surface of the member carrying the transfer material. 10. The electrophotographic apparatus according to claim 5, wherein the cleaning member is disposed in contact with the surface of the photoreceptor on which the developer image is formed. 11. The electrophotographic apparatus according to claim 9, wherein the cleaning member is a cloth-shaped member carrying particles that absorb a release agent. 12. A fixing rotator provided with a release agent,
In an electrophotographic apparatus provided with a fixing device for fixing a developer image transferred on a transfer material and a means for forming an image on both surfaces of the transfer material, a cleaning member having particles absorbing the release agent uses colloidal alumina. An electrophotographic apparatus, which is carried on a cloth-like member. 13. The electrophotographic apparatus according to claim 12, wherein the cleaning member is disposed in contact with the surface of the member carrying the transfer material.