JP2003050506A - Method for recycling developer carrier and recycled developer carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recycling a developer carrier by which the used developer carrier can be recycled by roughening a smoothed surface by performing blast treatment to a coating film formed on a developer carrying surface and removing stuck developer or contaminating substance, and a recycled developer carrier recycled by the recycling method. SOLUTION: The method for recycling the used developer carrier at least on whose developer carrying surface the coating film is formed is characteristic in it that the blast treatment is performed to the coating film. Then, the developer carrier can be recycled by performing the blast treatment at least to the coating film of the used developer carrier on whose developer carrying surface the coating film is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recycling a used developer carrier, which is a main functional member of a developing device in an electrophotographic copying machine, a laser printer or the like, and a used developer carrier. The present invention relates to a recycled developer carrier.

[0002]

2. Description of the Related Art A developer carrier is an OPC (organic photoconductor)
In order to develop the electrostatic image formed on the drum, it is a member that rotates in the developing device and transfers the developer (toner) to the developing position. As the developer, a magnetic one-component developer, a two-component developer or the like is used. Among them, in the developer carrier for the magnetic one-component developer, the surface of the substrate made of aluminum or its alloy is subjected to a roughening treatment by blasting in order to adjust the transfer amount of the developer. There is. In addition, a film may be provided on the surface of the developer carrier to adjust the triboelectric charge amount of the developer or prevent development ghost. As the coating, for example, a resin coating disclosed in JP-A-9-230690; Mo and O disclosed in JP-A-7-281517.
And H are the main constituents of the inorganic plating film; the Ni plating film disclosed in JP-A-8-202140; One of the above coatings is selected depending on the triboelectric charging characteristics of the developer used.

In order to support and rotate the developer carrying member, a flange is attached to the end of the developer carrying member and is incorporated in the developing device. The developing device may be incorporated in the cartridge for easy replacement by the user.

When a developing device is used, the developer carrying member rotates, and the surface thereof is repeatedly rubbed with the developer and the regulating member, so that the unevenness of the surface becomes gentle. Also,
If foreign material such as paper powder or coarse developer is caught between the developer carrier and the regulating member, the surface of the developer carrier will be smoothed or scratched in the circumferential direction of the developer carrier. I have something to do. Since such a phenomenon occurs with the use of the developing device, which causes deterioration of image quality, conventionally, when the developer is consumed, it is determined that it has reached the end of its life, and the entire developing device is replaced and discarded. It was

However, in recent years, it has been socially desired to take out and reuse usable members in order to reduce waste, effectively use resources, etc., and the developer carrying member should also be taken out from the developing device. It is preferable to reuse. But,
As described above, if the surface of the developer bearing member has a reduced surface roughness or is scratched and reused as it is, the image density is low, and streak-like uneven development density is caused in response to the scratch. However, there was a problem that the image quality was inferior to that of a new product, and it could not be treated the same as a new product. Further, since the developer and contaminants may stick to the concave portions of the rough surface, there is also a disadvantage that cleaning is troublesome.

As a method for removing the stuck developer and contaminants, a method of washing the developer carrier with a solvent that dissolves them can be considered. However, it is difficult to completely remove it by washing with a solvent, and there is also a problem of high cost because a treatment facility for the solvent after washing is required.

[0007]

From the above, the present invention is
By blasting the film formed on the developer carrying surface to roughen the smoothed surface and remove the fixed developer and contaminants, the used developer carrying body is regenerated. It is an object of the present invention to provide a method for regenerating a developer carrier which can be carried out and a regenerated developer carrier regenerated by the method.

[0008]

The above object can be achieved by the present invention described below. That is, the present invention relates to <1> a method for recycling a used developer carrier having a film formed on at least a developer carrying surface, characterized in that the film is blasted. This is how to regenerate the body. <2> A regenerated developer carrying member, characterized in that the used developer carrying member having a film formed on at least a developer carrying surface is reclaimed by blasting the film.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION <Regeneration Method of Developer Carrier> The regeneration method of the developer carrier of the present invention is a method of regenerating a used developer carrier having a film formed on at least the developer supporting surface. Therefore, the coating film is subjected to a blast treatment. As the "used developer carrier" which is the target of the method for regenerating the developer carrier of the present invention, it is determined that the developer carrier is used and the developer is no longer consumed, which is the so-called lifetime. Not only the developed developer carrier but also the developer carrier that has been used once or more without reaching the end of its life is included.

FIG. 1 is an explanatory view for explaining the outline of the blasting process carried out in the method for recycling the developer carrying member of the present invention. As shown in FIG. 1, the blasting process is performed by polishing powder 3
Is sprayed from the nozzle 2 together with a fluid such as air onto the film of the used developer carrier 1 rotating in the circumferential direction to roughen the surface. The roughness of the unevenness formed by the blast treatment is 0.8 to 3 in terms of arithmetic average roughness Ra.
The thickness is preferably 0 μm, and more preferably 1.0 to 2.5 μm. If Ra is less than 0.8 μm, the amount of developer conveyed is insufficient, and it may be difficult to maintain an appropriate image density. On the contrary, if it exceeds 3.0 μm,
Since the developer transport amount becomes excessive and the layer of the developer that adheres to the image area becomes thick, it may cause image quality deterioration such as thick line drawing, and the consumption amount of the developer becomes larger than necessary. There is. The average mountain interval Sm is 50 to 300.
The thickness is preferably μm, more preferably 100 to 200 μm. If Sm is less than 50 μm, clogging of the developer is likely to occur, and if Sm is more than 300 μm, the developer transport amount becomes insufficient. Ra and Sm can be adjusted by the type (material) of polishing powder, shape, size, spraying pressure and the like.

There is no particular limitation on the type of the polishing powder 3.
However, preferably a metal oxide is used, and particularly preferably
Zirconia, glass beads, alumina, etc. are used.
The particle size of the polishing powder 3 is not particularly limited, but # 40 (0.1
25 to 0.425 μm) to # 120 (0.25 to 0.
It is preferably in the range of 35 μm). True of polishing powder 3
A specific gravity of 2.0 to 4.5 is usually used, but it is preferable.
Preferably 2.5 to 4.0 is used. Blasting
There is no particular restriction on the spraying pressure that makes sense, but it is 0.15
kg / cm ²~ 0.25kg / cm²Is preferred, and 0.1
8 to 0.22 kg / cm²Is more preferable. Spray pressure
Power is 0.25kg / cm²If it exceeds, the surface coating layer will peel off.
It is easy to get rid of, 0.15 kg / cm²Play when less than
Will be less effective. Type of polishing powder, specific gravity of polishing powder, grain
Regeneration conditions such as diameter and spray pressure are not always the same as when manufacturing a new product.
Must be the same as the blasting conditions applied to the substrate, etc.
Instead, it is determined according to the type of surface coating layer and the like.

The developer carrying member is used by being housed in a developing device. Therefore, in practice, the developer carrying member determined to require the regenerating treatment is taken out of the developing device and subjected to the above-mentioned blasting treatment on the surface of the coating to roughen the entire surface of the coating as before. In the case where the surface roughness is reduced by the blast treatment, the surface roughness returns to the original value, and in the case where the average crest interval is widened, it returns to the original value. Those with scratches are roughened, including the scratched parts, so that the effects of scratches disappear.
Blasting is also performed on the non-problematic part, but the problem due to overblasting is the only thing that the surface of the developer carrying member is shaved.Therefore, blasting is possible unless the coating is lost. Can be repeated as many times. Only the surface portion of the coating is smoothed or scratched by use, and there is no problem if the thickness has a margin, but of course, if the coating itself is worn, it cannot be reused. Even if the surface of the developer carrying member taken out from the developing device is clogged with developer or other dust, the dust can be quickly removed by blasting the surface. The task is easier than manually scraping off the dirt. It should be noted that it is preferable that the conditions of the blasting process during reproduction are actually adjusted depending on the finished state.

<Recycled Developer Carrier> The recycled developer carrier of the present invention is a recycled developer carrier regenerated by the above-described developer carrier recycling method of the present invention. That is, it is regenerated by subjecting the above-mentioned coating of a used developer carrying member having a coating formed on at least the developer carrying surface to a blast treatment. Here, the developer carrying surface is a surface on which the developer is attracted and adhered, and the developer is attached when the developer is conveyed to the photosensitive drum as the developer carrying body rotates, and the entire peripheral surface of the developer carrying body. Or the entire surface excluding the end portion, or the range is appropriately set depending on the application.

The developer carrying member before use is not particularly limited as long as it has a film formed on at least the developer carrying surface. Specifically, the developer carrying surface of a cylindrical substrate is provided with a film. And a tracking member for adjusting the distance to the photosensitive drum is abutted.

Examples of the material of the base include aluminum, its alloys, SUS, etc., which are made into a cylindrical raw tube by extrusion, drawing, etc. A tube whose surface is smoothed by various methods such as polishing, grinding and grinding. Among these,
For example, a cylindrical substrate surface-treated by the centerless polishing method described in JP-A-4-301647 is
It is preferable from the viewpoint of dimensional accuracy and cost. It is preferable that the cylindrical substrate or the like be subjected to a cleaning treatment for removing dirt such as fats and oils, and then to a roughening treatment.

As a method of the surface roughening treatment, a blasting process of spraying particles by a dry method is the most preferable in terms of stability of roughness, productivity and cost. The arithmetic average roughness Ra after the surface roughening is preferably 0.8 to 3.0 μm, more preferably 1.5 to 2.5 μm. During the roughening process, the average surface roughness can be controlled within the above range by controlling the type, size, shape and pressure of the particles.

A coating is formed on at least the developer carrying surface of the substrate after the surface roughening treatment. By forming the film, it is possible to prevent abrasion, adjust the triboelectric charge amount of the developer, and / or prevent development ghost from occurring. Therefore, the composition and the like of the coating can be appropriately selected according to the desired characteristics.

For example, when the substrate is aluminum, the phenomenon that the surface roughness is lowered due to friction with the developer, that is, abrasion is likely to occur. In order to prevent this, it is preferable to form a hard plating film such as a hard alumite film, a Cr plating film, or a Ni plating film described in JP-A-8-202140 (paragraph 0009 and paragraph 0018). Further, the adjustment of the triboelectric charge amount of the developer is
This is performed when the amount of triboelectrification that the developer is charged by friction with aluminum is different from the desired amount of charge for development, and forms a metal other than aluminum or its compound, or a semiconductive resin coating on the substrate surface. Preferably. Examples of such a coating include a plating coating such as a Cr plating coating, a Ni plating coating, and a steel plating coating.

The plating film may be electroplated or electroless plated, and both may be used. Among these, the electroless plating film using Ni is preferable for preventing abrasion of the developer carrier and adjusting the triboelectric charge amount of the developer, and the plating film is formed, for example, with a sulfuric acid which is a nickel salt. The substrate is immersed in a solution containing nickel or nickel chloride, citric acid as a complexing agent, sodium hypophosphite as a reducing agent, and a pH adjusting agent. Before the plating treatment, a palladium catalyst layer is formed with a solution of palladium chloride and stannous chloride,
A zinc film may be formed by chemical plating. The thickness of the plating film can be controlled by the processing time,
It is preferably in the range of 0.8 to 10 μm, and 2 to 5
More preferably, it is μm. If the film thickness is thicker than 10 μm, the adhesion of the coating film may decrease and the cost may increase. If the film thickness is less than 0.8 μm, the durability against abrasion may be insufficient. In the case of a plated coating, the roughness of the coating surface is almost the same as the roughness of the substrate surface, or Ra is 0.1.
It becomes about 0.3 μm smaller.

The development ghost is a phenomenon that occurs when the triboelectric charge amount of the developer changes each time the developer carrying member rotates, and in order to prevent it, the charge amount due to the triboelectric charge of the developer is It is preferable to form a coating film on the surface of the substrate to prevent the change of the triboelectric charge amount by balancing the increase and the decrease of the electric charge amount due to the discharge from the surface of the developer. Examples of such a coating include, for example, a coating described in JP-A-7-44020 and containing Cr, O, and H as main constituent components, and Mo described in JP-A-7-2315178. Coating containing O and H as main constituents
Examples thereof include a resin coating described in Japanese Patent Publication No. 236984.

The coating containing Mo, O and H as the main constituents described in JP-A-7-2315178 is prepared by immersing a substrate in a solution containing molybdate and using the substrate as a cathode. It is formed by plating. The structure of the coating is considered to be a double-salt colloidal film containing Mo (OH) ₃ and Mo (OH) · MoO ₄ as main components. Although there are fine cracks in the coating film, if the width thereof is 0.3 μm or less, the durability of the development ghost suppressing effect can be improved. Adhesion of the coating can be improved by forming a zinc film by chemical plating on the substrate in advance as a base treatment.

The resin coating described in the above-mentioned Japanese Patent Application Laid-Open No. 9-236984 is a binder resin such as a phenol resin, an acrylic resin, a melamine resin, a urethane resin or an epoxy resin, and carbon black, graphite or carbon fiber. It is formed by dispersing conductive or semi-conductive particles such as metal powder, tin oxide, molybdenum disulfide, etc. and coating them on a substrate. The most preferable binder resin is a phenol resin. The film thickness of the coating is in the range of 5 to 30 μm,
It is particularly preferably 10 to 20 μm. When a resin coating is provided, the coating itself has a Ra of 0.8 to 3.0 μm, S
If it has a rough surface characteristic of 50 to 300 μm in m, it is possible to omit the blasting treatment applied to the surface of the substrate before forming the coating film.

A flange, a tracking agent and the like are attached to the end portion of the developer carrier before use having the above coating. As a method for attaching the flange, there are methods such as adhesion with an adhesive, caulking, and press fitting. Such a developer carrying member is mainly used in a developing device using a magnetic one-component developer. As the magnetic one-component developer, a known one mainly composed of magnetic powder, a binder resin for fixing, and other charge control agents can be used.

The developer carrying member has a multi-pole magnet 12 inside.
Is attached and used by being accommodated in the developing device 13 as shown in FIG. In the developing step in which the developer is actually developed, the developer carrying member 10 is rotated in the direction of arrow A, and the magnetic force of the multi-pole magnet 12 attracts the developer 15 onto the developer carrying surface of the developer carrying member 10. Next, the layer thickness of the developer 15 is controlled to be constant by pressing the regulating member 14, and the developer 15 is charged by friction at that time. Although the restriction member 14 is attached to the support member 11, the support member 11 may have elasticity.

To use the developer carrier 10. Since it is necessary to keep the distance between the photosensitive drum 16 and the photosensitive drum 16 constant, for example, in the range of 100 to 300 μm, the distance between the two is called a tracking member at both ends of the developer carrying member 10 which is a non-image forming portion. It is preferable to bring a member for holding into contact (not shown). The development is performed by the developer 15 flying from the developer carrier 10 onto the photosensitive drum 16 at a portion where the developer 15 faces the photosensitive drum 16. Developer 15
A developing bias voltage is applied to the developer carrier 10 in order to control the flight of the toner.

By using the developer carrying member as described above, if the developer carrying member has a problem such as the end of its service life or the occurrence of scratches, the developer carrying member of the present invention is regenerated. By regenerating by the method, the regenerated developer carrier of the present invention having the same characteristics as the developer carrier before use can be prepared.

[0027]

Example (Example 1) -Preparation of developer carrying body-After drawing an aluminum raw tube having an outer diameter of 18 mmφ and a length of 322 mm, the surface was subjected to R by a centerless polishing machine.
A substrate was prepared by processing so that a = 0.2 μm. The axial direction of the substrate is set to be vertical, the upper and lower sides of the substrate are covered with a cap, and a blast treatment with polishing powder (zirconia # 120) is applied for 2.0 seconds while rotating at 60 rpm.
The surface was roughened so that Ra = 2.0 μm and Sm = 180 μm.

Next, the surface of the substrate was subjected to zinc undercoating. The treatment was performed by immersing the substrate in a solution containing 100 g of NaOH (sodium hydroxide) and 10 g of Zn in 1 liter of water for 50 seconds. 3.0μ thick on the zinc substrate after treatment
m electroless nickel plating film was formed. The electroless nickel plating film was formed by immersing the substrate in a treatment liquid containing 25 g of nickel sulfate, 20 g of citric acid, 15 g of sodium hypophosphite, and other additives in 1 liter of water for 15 minutes.

Then, an aluminum flange was bonded to one end of the base using an anaerobic adhesive. After leaving it for 1 hour, insert a 4-pole magnet into the inside of the base body, press fit a flange made of polycarbonate resin into the opposite end,
A developer carrier was prepared. In the same manner as above, a total of five developer carrying members were produced.

-Development test-Each of the above-described developer carrying members is incorporated into a developing device, and further, a digital copying machine (Able140 manufactured by Fuji Xerox).
5), and a development test was conducted under the following conditions.

Developer: 50% volume diameter (d50) is 7μ
A negative magnetic one-component developer of m, to which hydrophobic silica having a primary particle volume average particle diameter of 16 nm is attached as an external additive. The filling amount in the developing device was 1350 g.・ Process speed: 173 mm / s ・ Peripheral speed ratio of developer carrier to drum: 1: 1 ・ Gap between developer carrier and drum: 250 μm ・ Tracking method: thickness 250 μm, length 5 mm
A method in which caps made of polyacetal resin are fitted on both ends of the developer carrier. -Drum charging condition: Vh = -350V and Vl = -60V are set by contact charging using a charging roll. -Development bias: DC-240V, 2.2kV, 2.4k
Applying a voltage that superimposes the current transformation voltage of Hz to the developer carrier. -Regulating member: A member in which urethane rubber having a thickness of 1 mm and a width of 5 mm is attached to a supporting member having a thickness of 1 mm.・ Pressing pressure of regulating member: 0.3N / cm

Evaluation is a character image (image part is 6% of white background)
The A4 size print on which was formed was output by alternately changing the type of paper to 100 sheets each of thin and thick. This was tested for each of the five developers. As a result of the image observation, there was no problem from the 1st sheet to the 23000th sheet, but in each case, the density decreased in a streak shape from around 25,000 sheets. This is because the developer was running short, and it was judged that the life of the developing device was reached at that time. In addition, in one of the five units, white lines were conspicuous in the solid black image in addition to the streaks.

-Regeneration of used developer carrier-The developer carrier was taken out from each developing device and the surface roughness was measured. Ra = 1.8 to 1.9 µm, Sm = 200 to
It was 220 μm, which was slightly gradual. In the developer bearing member where the white line was noticeable, the surface of the developer bearing member corresponding to the white line was Ra = 0.2 μm (S
m was not measurable) and was smoothed. It is considered that this smoothing occurs due to accelerated wear due to the coarse developer being sandwiched between the developer carrying member and the regulating member. On the other hand, the film thickness of the electroless nickel plating film was 1.9 μm, which was almost the same as that of the new product. Next, with the flange and the internal magnet still attached, as shown in FIG. 1, the polishing powder 3 (zirconia # 120, SE
The surface was subjected to a blast treatment using a PR company, trade name: ZIRBLAST B-120). At that time, make sure that the polishing powder does not fly to the flange portion, rotate at 60 rpm, the processing time is 14 seconds, and the spraying pressure is 0.2 kg /
It was set to cm ² . When the surface roughness is measured, Ra = 2.0
μm, Sm = 180 μm, and Ra = 0.2 μm
The area smoothed to m was also Ra = 1.8 μm. These developer carriers could be used just like new ones.

(Comparative Example 1) -Preparation of developer carrier and development test-Five developer carriers were prepared in the same manner as in Example 1.
Each was incorporated into a developing device and a development test was conducted. As in Example 1, the density decreased in a streak shape from around 25,000 sheets. In addition, in one of the five units, a white line was conspicuous in the solid black image, apart from the streaks, as in Example 1.

-Regeneration of used developer carrier-After removing the developer carrier from each developing device and wiping the surface of the developer carrier with a cloth impregnated with acetone in order to remove surface dirt , Reused as is. The four developer carriers other than the one having the partially smoothed portion were comparable to the new ones only in that the roughness became gentle, but in order to reuse them, it was necessary to wipe the surface. Was needed. However, if the blasting treatment is performed, it is easier to perform the blasting treatment without wiping the surface of the entire collected developer carrier. In addition, in the case where there is a partially smoothed portion, when reused, a white line was still generated in a solid black image. In order to reuse this, it is necessary to perform blast processing.

(Example 2) -Preparation of developer carrier-Phenolic resin (trade name: D3, manufactured by Dainippon Ink, solid content 40%) 100 parts (mass parts, hereinafter the same), carbon black 20 parts, graphite 40 parts are mixed and dispersed by a sand mill disperser for 2 hours, and acetone is added to adjust the viscosity to 75
The paint was adjusted to mPa · s. Using this coating composition, the same substrate as in Example 1 was applied by dip coating without blasting. After application, allow the coating to air dry for 5 minutes, then
Four developer carrying members were prepared in the same manner as in Example 1 by heating at 160 ° C. for 30 minutes for curing. The film thickness is 1
It is 5 μm, and when the roughness of the film is measured, Ra = 1.8.
μm and Sm = 200 μm. This is because the surface of the coating is rough because graphite is dispersed in the coating.

-Development Test- Each of these developer carrying members was incorporated in a developing device, and a development test was conducted under the same conditions as in Example 1. Looking at the results,
The density decreased linearly from around 25,000 images, and it was determined that the life of the developing device was reached. At that time, the density of the entire surface of the image was lower than that at the initial stage. —Regeneration of Used Developer Carrier— When the developer carrier was taken out of the developing device and the surface roughness was measured, Ra was 1.5 μm and Sm was 220 μm. In the development test, since the image density was lower than the initial value, it is considered that the resin coating is more easily worn than the Ni coating. Next, the surface of the developer bearing member was blasted. Glass beads # 60 (trade name: Fuji Glass Beads FGB60, manufactured by Fuji Manufacturing Co., Ltd.) were used as the polishing powder, and the treatment time was 10 seconds. The surface roughness after blasting was measured to be Ra = 1.8 μm, Sm = 200.
It had recovered to μm. These developer carriers could be used just like new ones.

(Comparative Example 2) -Preparation of developer carrier and development test-Four developer carriers were prepared in the same manner as in Example 2, and each was incorporated in a developing device to conduct a development test. Similar to Example 2, the density decreased in a streak shape from around 25,000 sheets.

-Regeneration of used developer carrier-After removing the developer carrier from each developing unit and wiping the surface of the developer carrier with a cloth impregnated with acetone in order to remove surface dirt. , Reused as is. The developer bearing member was comparable to a new one only in that the roughness became gentle, but it was necessary to wipe the surface in order to reuse it. If blasting is to be performed, it is easier to perform blasting on the entire collected developer carrier without wiping the surface.

[0040]

According to the present invention, the film formed on the developer carrying surface is blasted to roughen the smoothed surface and remove the fixed developer and contaminants. Thus, it is possible to provide a method for regenerating a used developer carrier and a regenerated developer carrier.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating an outline of a blasting process performed in a method for recycling a developer carrier according to the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of a developing device.

[Explanation of symbols]

1 ... Used developer carrier 2 ... Nozzle 3 ... Abrasive powder

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsuhisa Arai             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Issei Koga             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Yuichi Yashiki             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. F-term (reference) 2H077 AD06 DB14 FA03 GA04

Claims (2)

[Claims] 1. A method for reclaiming a used developer carrier having a coating film formed on at least a developer supporting surface, wherein the film is subjected to a blast treatment. . 2. A regenerated developer carrying member, characterized in that a used developer carrying member having a film formed on at least a developer carrying surface is subjected to a blast treatment to be reclaimed.