JPH09258632A - Cleaning blade and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning blade by which turn-up is hardly caused by providing a coating layer consisting of a fluoropolymer at the part of the blade abutting on a toner sticking body. SOLUTION: The edge part 23a of the cleaning blade 23 held by a holder 22 fixed on a toner recovery container 21 abuts on a photoreceptor 11 so that it may rotate reversely to the rotating direction of the photoreceptor 11 so as to mechanically scrape the residual toner on the surface of the photoreceptor 11. The edge part 23a of the blade 23 abutting on the photoreceptor 11 is provided with the coating layer consisting of the fluoropolymer in which fluororesin powder is dispersed. For example, the coating layer is formed by applying a dispersed body obtained by dispersing the fluororesin powder and the fluoropolymer in fluorosolvent. Thus, the friction factor of the photoreceptor 11 and the blade 23 is lowered to prevent initial turn-up. By providing a fluororesin lubricating layer at both ends in a width direction, especially, where the turn-up is easily caused further, the turn-up at both ends where the turn-up is easily caused is surely prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning blade for electrophotography, which is applied to a cleaning process for removing toner from an electrophotographic photoreceptor, and a method for manufacturing the same. The present invention can be applied not only for cleaning the electrophotographic photosensitive member but also for cleaning the transfer drum and the transfer belt used in the transfer process, the intermediate conveying belt, or the like.

[0002]

2. Description of the Related Art Generally, in an electrophotographic process, at least a charging process, an exposing process, a developing process, a transferring process and a cleaning process are performed on an electrophotographic photosensitive member, and a cycle of these processes is repeated. That is, FIG.
As shown in FIG. 3, a charging device 12, a document light image exposure mechanism 13, a developing device 14, a transfer electrode 15 and a separating electrode 16, a charge erasing electrode 17, and a cleaning mechanism 18 are provided around the electrophotographic photoreceptor 11. They are arranged in order. The toner attached to the electrostatic latent image on the surface of the photoconductor in the developing process by the developing device 14 is fed from the surface of the photoconductor by the paper feed roll 19 in the transfer process by the transfer electrode 15 and the separation electrode 16. The transfer material 20 such as paper is moved.

However, all the toner on the surface of the photoconductor cannot be moved to the transfer material due to reverse charging of the toner, unevenness and dirt on the surface of the photoconductor, lack of energy in the transfer device, etc. Remains. This residual toner blocks the photodischarge of the photoconductor in the exposure process of the photoconductor in the next cycle, and thus hinders the formation of a clear copy image. Therefore, the cleaning process after the transfer process is a very important process.

Currently, the mainstream cleaning method is a method using a cleaning blade, and among them, a counter method having an excellent cleaning property is often adopted. That is, as shown in FIG. 1, the edge portion 23a of the cleaning blade 23 held by the holder 22 fixed to the toner collecting device 21 is brought into contact with the photoconductor 11 so as to be reverse to the rotation direction of the photoconductor 11. It is a mechanism for mechanically scraping off the residual toner on the surface.

[0005]

However, in the above-described cleaning method, the edge portion 23 of the cleaning blade 23 which exhibits excellent cleaning properties.
Since a has a large frictional force with the photoconductor 11, the edge portion 2
3a has a defect that it is easy to turn over contrary to the counter direction like 23b. Especially the cleaning blade 23
Since stress concentrates at both ends of the edge portion 23a in the width direction, the curling is likely to occur.

In view of the above circumstances, the present invention provides a cleaning blade for a toner adhering member such as an electrophotographic photosensitive member, a transfer drum, or a transfer belt, which does not easily cause the above-mentioned curling, and a manufacturing method thereof. The challenge is to provide.

[0007]

A first aspect of the present invention for solving the above-mentioned problems is a cleaning blade used in a cleaning section for removing toner on a toner-adhered body, which is at least contacting the toner-adhered body. In the part that touches,
A cleaning blade having a coating layer made of a fluoropolymer in which fluororesin powder is dispersed.

Here, the coating layer is formed, for example, by coating a dispersion in which a fluorine resin powder and a fluorine polymer are dispersed in a fluorine solvent.

The coating layer is formed, for example, by spray coating or roll coating.

Further, a fluororesin-based lubricating layer may be provided as an upper layer or a lower layer of the coating layer on at least both ends in the width direction of the cleaning blade.

The fluororesin-based lubricant layer is formed, for example, by applying a fluororesin-based lubricant.

On the other hand, a second aspect of the present invention is a method of manufacturing a cleaning blade used in a cleaning unit for removing toner on a toner adhering member, wherein at least a portion contacting the toner adhering member is made of a fluorine-based material. It is a method of manufacturing a cleaning blade, which comprises a step of applying a dispersion in which a resin powder and a fluorine-based polymer are dispersed in a fluorine-based solvent.

Here, a step of applying a fluororesin-based lubricant to at least both widthwise ends of the cleaning blade by spray coating or roll coating may be included.

As described above, according to the present invention, since the coating layer made of the fluorine-based polymer in which the fluorine-based resin powder is dispersed is provided on the edge of the cleaning blade that is in contact with the photoreceptor, the photoreceptor and the blade are separated from each other. The coefficient of friction is reduced and initial turning is prevented. Further, in particular, by additionally providing a fluororesin-based lubricating layer on both ends in the width direction where the curling is likely to occur, curling of both ends where the curling is likely to occur is surely prevented.

It is conceivable to prevent the curling by simply rubbing a fluorine resin powder such as polytetrafluoroethylene (PTFE) or vinylidene fluoride (PVDF) on the edge of the cleaning blade. In this method, too much fluororesin powder adheres to the edges, and the fluororesin powder rises up due to vibration during assembly, transportation, or driving of the electrophotographic machine, causing the electrophotographic machine interior Another process component, such as a charging roll and a transfer roll, may be contaminated, which is not preferable.

Therefore, it is preferable to use a coating layer made of a fluoropolymer in which a fluororesin powder is dispersed as in the present invention. Further, such a coating layer can be easily formed by applying a dispersion in which a fluorine resin powder and a fluorine polymer are dispersed in a fluorine solvent.

Examples of the fluorine-based polymer or fluorine-based resin powder that can be used in the present invention include polytetrafluoroethylene (PTFE) and vinylidene fluoride (PVDF). Further, examples of the fluorine-based solvent include xylene hexafluoride and CFC alternative solvent.

The mixing ratio of the fluorine resin powder, the fluorine polymer and the fluorine solvent is, for example, 1 to 5% by weight of the fluorine resin composition, 1 to 5% by weight of the fluorine polymer and 96 of the fluorine solvent. ˜90% by weight.

Fluorine lubricants that can be used in the present invention are tetrafluoroethylene resin type Lubron and polyflon (both trade names; manufactured by Daikin Industries, Ltd.), vinylidene fluoride resin type Kyner ( Trade name; manufactured by Elf Atochem Co., Ltd. and the like, but not limited thereto.

On the other hand, as the cleaning rubber elastic body,
Examples include polyurethane rubber, silicone rubber, nitrile rubber, chloroprene rubber, etc., but wear resistance,
Polyurethane rubber is particularly desirable in terms of permanent set and contamination of the photoreceptor.

The cleaning blade of the present invention has a fluorine-containing polymer layer containing a fluorine-containing resin powder on at least the edge which comes into contact with the photosensitive member. The method for forming this fluorine-based polymer layer is not particularly limited, but briefly, using a dispersion obtained by dispersing a fluorine-based resin powder and a fluorine-based polymer in a fluorine-based solvent, for example, by spray coating or roll coating. Can be formed.

Further, in order to surely prevent the curling at both ends in the width direction where the curling is likely to occur, it is preferable to provide a fluorine-based lubricating layer at least on the edges of the both ends. Such a fluorinated lubricant layer may be simply formed by applying a fluorinated lubricant by, for example, spray coating or roll coating.

In order to manufacture the cleaning blade of the present invention, for example, a preformed urethane sheet is processed into a strip shape and adhered to a holder (supporting plate), and if necessary, fluorine-based material is applied to both ends. It is manufactured by applying a lubricant and then applying a dispersion in which a fluorine-based polymer and a fluorine-based resin powder are dispersed in a fluorine-based solvent.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION

(Examples 1 and 2) In both Examples 1 and 2, 1,4-butanediol and trimethylolpropane were mixed with the following urethane prepolymer melted by heating at the following compounding ratio and poured into a preheated mold. Molded and heat cured. After molding, width 15 mm, thickness 2.0 mm, length 310
A rubber elastic body cut into mm was formed, and this rubber elastic body was bonded to a support plate. Next, a fluorine-based lubricant is spray-applied to both ends in the width direction (longitudinal direction) of the edge portion of the rubber elastic body, and then the following fluorine-based polymer and fluorine-based resin are further applied to the tip end over the entire width direction. A dispersion prepared by dispersing the powder in a fluorine-based solvent was spray-coated to obtain the cleaning blade of the present invention.

(Compound of Example 1) Rubber elastic body (parts by weight) Ethylene adipate brepolymer 100 (Mn = 2000, NCO% = 6.5%) 1,4-butanediol 4.3 Trimethylolpropane 2. 2 ・ End fluorinated lubricant Polyflon spray wax (manufactured by Daikin Industries, Ltd.) ・ Fluorine polymer and fluororesin powder PTFE, PVDF ・ Fluorine solvent xylene hexafluoride, HCFC-225

(Compounding of Example 2) Rubber elastic body (parts by weight) Ethylene adipate prepolymer 100 (Mn = 2000, NCO% = 6.5%) 1,4-butanediol 4.3 Trimethylolpropane 2. 2 ・ Fluorine-based lubricant Lubron spray wax (manufactured by Daikin Industries, Ltd.) ・ Fluorine-based polymer and fluorine-based resin powder PTFE, PVDF ・ Fluorine-based solvent xylene hexafluoride, HCFC-225

(Comparative Example) A rubber elastic body similar to that of Example 1 was obtained, cut into the same size, and attached to a support plate.
A cleaning blade was obtained.

The cleaning blades manufactured in Examples 1 and 2 and Comparative Example 1 were attached to an electrophotographic copying machine using an organic photoconductor, and the curling property was evaluated. In Examples 1 and 2, low temperature and low humidity were observed. Normal temperature / humidity, high temperature /
In all of the high-humidity environments, no flipping occurred, but in Comparative Example 1, flipping occurred immediately.
Further, Examples 1 and 2 were also excellent in cleaning performance.

[0029]

The cleaning blade according to the present invention is
By significantly reducing the coefficient of friction between the toner adherent and the blade, it is possible to prevent the initial curling without contaminating other process parts of the electrophotographic machine,
It is also excellent in cleaning performance.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view illustrating the operation of an electrophotographic machine that uses a cleaning blade.

[Explanation of symbols]

11 Electrophotographic Photoreceptor 12 Charging Device 13 Original Light Image Exposure Mechanism 14 Developer 15 Transfer Electrode 16 Separation Electrode 17 Charge Erasing Exposure Mechanism 18 Cleaning Mechanism 19 Paper Feed Roll 20 Transfer Material 21 Toner Recovery Box 22 Holder 23 Cleaning Blade 23a Edge of cleaning blade that is functioning normally 23b Edge of cleaning blade when flipped

Claims (6)

[Claims] 1. A cleaning blade used in a cleaning unit for removing toner on a toner adhering member, wherein at least a portion contacting the toner adhering member is made of a fluoropolymer in which a fluororesin powder is dispersed. A cleaning blade having a coating layer. 2. The cleaning blade according to claim 1, wherein the coating layer is formed by coating a dispersion obtained by dispersing a fluorine-based resin powder and a fluorine-based polymer in a fluorine-based solvent. . 3. The cleaning blade according to claim 1, further comprising a fluororesin-based lubricating layer as an upper layer or a lower layer of the coating layer at least at both widthwise end portions of the cleaning blade. 4. The cleaning blade according to claim 1, wherein the fluororesin-based lubricating layer is formed by applying a fluororesin-based lubricant. 5. A method of manufacturing a cleaning blade used in a cleaning unit for removing toner on a toner-adhered body, comprising a fluorine-based resin powder and a fluorine-based polymer at least in a portion in contact with the toner-adhered body. A method of manufacturing a cleaning blade, comprising a step of applying a dispersion dispersed in a fluorine-based solvent. 6. The method of manufacturing a cleaning blade according to claim 5, including a step of applying a fluororesin-based lubricant to at least both widthwise end portions of the cleaning blade.