JPH03223878A - Manufacture of developer carrier - Google Patents

Abstract

PURPOSE:To improve picture quality by arranging an elastic body roll which is provided with a soft elastic body layer integrally inside a mold material where an overcoat layer and an elastic cylinder layer are laminated, adhering the soft elastic body layer and elastic cylinder layer, and separating a shaft, the soft elastic body layer, the elastic cylinder layer, and the overcoat layer from the mold material. CONSTITUTION:The electric roll 14 formed by fixing the soft elastic body layer 13 made of a foamed body around the shaft 11 with an adhesive 12 integrally is arranged inside the mold material 100 where the overcoat layer 17 and elastic cylinder layer 16 are laminated, and the soft elastic body layer 13 and elastic cylinder layer 16 are adhered together with the adhesive 15. Then the adhesive 15 is set sufficiently and the united shaft 11, soft elastic body layer 13, elastic cylinder layer 16, and overcoat layer 17 are drawn and removed from the mold material 100 as shown by an arrow A to obtain the developer carrier 6. High- level softness is obtained by the soft elastic body layer 13 and the surface of the overcoat layer 17 can be made smooth with high accuracy. Consequently, the picture quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developer carrier used in a developing device of an image forming apparatus.

[Prior Art and Problems to be Solved by the Invention] In image forming apparatuses such as copying machines, facsimile machines, and printers, an electrostatic latent image is formed on a latent image carrier.

Dry type developing devices are widely used to visualize this. In such developing devices, a two-component developer having a magnetic carrier and a toner, or a developing device using a magnetic-component developer composed of a magnetic toner to which an auxiliary agent is added as necessary is often used. . In such a developing device, a cylindrical developing sleeve is generally used as a developer carrier, but this is not the case.

Since the developer is magnetically conveyed around the developing sleeve, a permanent magnet or the like is required inside the developing sleeve, which complicates the overall structure and increases the cost of the developing device. or.

Their bulk, weight, and driving torque also increase. Especially in developing devices such as color copying machines that use multiple developing devices, the developing devices themselves become bulky, their weight increases, and their active torque tends to increase. ing. Furthermore, in those using magnetic component type developers, it is difficult to form beautiful color images because the toner contains a magnetic substance.

For developing devices that are subject to such various restrictions.

Developing devices that use non-magnetic one-component developers that do not require magnetic conveyance of the developer have recently come into use. In this developing device, conventionally, as a developer carrier,
A rubber roller with a single layer of rubber layered on the shaft is used, and as a whole it is almost a rigid body,
When it rotates in contact with the latent image carrier, the toner on the carrier is scraped off, resulting in a problem of deterioration of image quality, particularly gradation reproducibility. Further, the mechanical frictional force against the surface of the latent image carrier increases, which may cause wear of the latent image carrier and shorten its lifespan. Additionally, the frictional force of the toner layer regulating blade, toner supply member, etc. that comes into contact with the developer carrier increases, making it easier for toner filming and scratches to occur on the surface of the developer carrier, which may lead to a decrease in image quality. .

Furthermore, as the frictional force increases, there is a problem in that the dynamic torque applied to the developer carrier increases, making it particularly difficult to miniaturize color image forming apparatuses.

An object of the present invention is to provide a method for manufacturing a developer carrier for a developing device using a non-magnetic one-component developer, which can eliminate the various drawbacks described above.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention provides a method for manufacturing a developer carrier that visualizes an electrostatic latent image formed on the latent image carrier by a non-magnetic one-component developer carried on the outer peripheral surface. An overcoat layer and an elastic cylinder layer made of a rubber material are sequentially laminated on the inner surface of a cylindrical shape material, and an elastic roll is formed by integrally providing a soft elastic layer made of foam around the shaft. An elastic cylinder layer is placed inside the laminated mold material, the soft elastic layer and the elastic cylinder layer are adhered, and the shaft, the soft elastic material layer, the elastic cylinder layer, and the overcoat layer are released from the mold material. We propose a method for manufacturing a developer carrier.

〔Example〕

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

FIG. 1 is a schematic diagram showing an example of a developing device having a developer carrier manufactured by the method according to the present invention, and reference numeral 1 denotes a drum-shaped photoreceptor, which is an example of the structure of the latent image carrier. show. The photoreceptor 1 is rotated in the direction of the arrow, and its surface is subjected to well-known charging and exposure to form an electrostatic latent image. Opposed to the photoreceptor 1 is a developing section w2 having a cartridge structure and not having a toner replenishing section, which is found in developing devices using two-component developers.

A non-magnetic one-component developer (hereinafter referred to as toner) 3 made of non-magnetic toner to which an auxiliary agent is added as necessary is contained in the developing device 2, and this is consumed and contributes to image formation. When it becomes impossible to do so, the developing device 2 is replaced with a new one.

A developer carrier 6 is provided in the developing device 2 , and in this example, the developer carrier 6 is in contact with the photoreceptor 1 .

Inside the developing device 2, there is an agitator 4 having four elastic plates.
The agitator 4 rotates in the direction of the arrow to prevent the toner inside from becoming blocked, and also supplies toner to the toner supply member 5. The latter toner supply member 5 is made of a soft elastic body such as a sponge roll, rotates in frictional contact with the developer carrier 6 in the direction of the arrow, and electrostatically charges the toner against the developer carrier 6 while frictionally charging the toner. Supplied by adhering to.

The developer carrier 6 is rotatably driven in the direction of the arrow shown in the figure, which is the same direction as the direction of movement of the outer circumferential surface of the photoreceptor 1, and the toner electrostatically supported on the surface of the developer carrier 6 is transported in the direction of rotation. The layer thickness is leveled by the leveling member 7a while the toner layer is being loosened, and the excess is scraped off by the toner layer regulating blade 7 to reduce the thickness to, for example, a single layer. At this time,
at the same time.

The toner is triboelectrically charged uniformly and transported toward the developing section 9. Then, at the developing section 9, the carried toner is transferred to the electrostatic latent image formed on the surface of the photoreceptor 1, and the electrostatic latent image is visualized.

Note that the reference numeral 8 is a static eliminating member, which removes toner and static charges remaining on the developer carrier 6 after development, and removes the surface condition and electrostatic state on the developer carrier 6. Initialize.

FIG. 2 shows an example of the structure of the developer carrier 6. This carrier 6 is made of an elastic material in which a cylindrical soft elastic layer 13 made of foam is fixedly formed around a shaft 11 made of a metal conductor. A body roll 14 , an elastic cylinder layer 16 with a smooth rubber backing and a smooth surface adhered to the elastic body roll 14 , and an overcoat layer 17 of, for example, insulating or semiconductive formed on the outer peripheral surface of the cylinder layer 16 . It has a multi-layered structure.

In this example, the adhesive 12 connects the shaft 11 to the soft elastic layer 1.
3 are integrated with each other, and an elastic cylinder layer 16 is integrated with the elastic roll 14 by an adhesive 15.

The cylindrical soft elastic layer 13 is made of a foam such as sponge rubber, urethane foam, or polyethylene foam. Generally, to form a developing electric field between the photoreceptor 1 and the developer carrier 6.

A developing bias voltage is applied to the toner carrier 6, and when this developing bias voltage is applied to the soft elastic layer 13, the soft elastic layer 13 is made of the above-mentioned soft resin foam. It is convenient to use a material containing carbon black or other conductive fine powder. On the other hand, conductive fine powder is applied to the soft elastic layer 1.
3, or a soft elastic body in which conductive fine powder is dispersed may be coated around the soft elastic body forming the base body.

A conductive liquid made by dissolving RTV silicone rubber (for example, RE9140 manufactured by Toray Silicone Co., Ltd.) and carbon black (for example, MS-500 manufactured by Asahi Carbon Co., Ltd.) in a solvent is coated on the surface of a foam such as urethane foam, and then dried. The soft elastic layer 13 can also be formed by curing.

When the adhesive 15 contains conductive fine powder such as carbon black, it becomes easier to apply a developing bias voltage. For example, R
An adhesive made of a rubber material such as TV silicone rubber or a resin material containing conductive fine powder such as carbon black can be used. After all, such an adhesive layer can also function as an electrode layer for applying a developing bias voltage.

As the elastic cylinder layer 16, rubber materials such as natural rubber (NR), silicone rubber, urethane rubber, butyl rubber, ethylene propylene rubber, chloroprene rubber, and chlorosulfonated polyethylene (CSM) are used.

In addition, the elastic cylinder layer 16 may be made by incorporating conductive fine powder such as carbon black into the above-mentioned rubber material to make it conductive or semi-conductive. It may also have a two-layer structure of an insulating layer that does not contain the insulating layer and a conductive layer that contains the insulating layer.

The overcoat layer 17 is a layer that supports toner, and its material includes toner transportability, toner filming prevention properties, abrasion resistance, toner charging property to a predetermined polarity, and adhesiveness with the elastic cylinder layer 16. A material is selected so that the elastic cylinder layer 16 has good followability to mechanical deformation. For example, materials such as urethane resin, silicone resin, and fluorine-containing resin are suitable.

The developer carrier 6 configured as described above is incorporated into a developing device as shown in FIG. Ru. At this time, since the developer carrier 6 has the soft elastic layer 13 made of foam, the entire developer carrier 6 has great elasticity and is made soft.

As mentioned above, the elastic cylinder layer 16 is made of a rubber material, and its surface is smoother than that of the cylindrical soft elastic layer 13 made of urethane foam or the like.
By coating this surface with a thin layer of overcoat layer 17, this surface is also maintained as a smooth surface.

In this way, the inner soft elastic layer 13 gives overall elasticity to the developer carrier 6, and the outer elastic cylinder layer 16
works to provide smoothness to the surface of the developer carrier 6, so it is possible to compensate for each other's weak points, and it is possible to absorb rotational vibration of the photoreceptor 1, and due to its smoothness, toner It becomes possible to uniformly adhere the photoreceptor 1 to the photoreceptor 1.

Previously, it had a single layer structure made of only rubber,
Although it is possible to apply toner uniformly, it has poor followability to the photoreceptor, which tends to wear out the photoreceptor early and shorten its lifespan. Due to its nature, this problem can be improved. Further, the scraping property of the toner is reduced, and a high-quality image with good one-tone gradation can be obtained. Furthermore, since the smoothness of the outer surface can be maintained, it is possible to ensure that toner adheres uniformly in the developing section, and the frictional force between the toner layer regulating blade and the toner supply member can be reduced, and the developer The occurrence of scratches and toner filming on the carrier can be suppressed, and the driving torque of the developer carrier can also be reduced. Therefore, it is possible to downsize the developing device, and it can be particularly advantageously applied to a color image forming device.

Next, an example of a method for manufacturing the above-mentioned developer carrier 6 will be explained with reference to FIG.

First, as shown in FIG. 3(a), a cylindrical shaped material 100 is prepared, and an overcoat layer 17 on its inner surface and an elastic cylinder layer 16 made of a rubber material are sequentially laminated by, for example, a dipping method. Next, an adhesive 15 is applied to the inner surface of the elastic cylinder layer 16 as shown in FIG. 3(b). As can be seen from the previous example, the elastic cylinder layer 16 and adhesive 15 are made of a rubber material such as RTV silicone rubber mixed with conductive fine particles such as carbon black, and are uncured or semi-cured. Figure 3 (
Proceed to step c).

That is, in FIG. 3(c), there is an elastic roll 14 in which a soft elastic layer 13 made of foam is integrally fixed around a shaft 11 with an adhesive 12.

The soft elastic body layer 13 and the elastic cylinder layer 16 are placed inside the above-described mold material 100 in which the overcoat layer 17 and the elastic cylinder layer 16 are laminated, and the soft elastic body layer 13 and the elastic cylinder layer 16 are brought into contact with each other by the adhesive 15 . In this way, each layer is all integrated.

Next, after the adhesive IS has sufficiently hardened, the adhesive shown in FIG.
), an integrated shaft 11, soft elastic layer 13
, the elastic cylinder layer 16 and the overcoat layer 17 are pulled out and released from the mold material 100 as shown by arrow A, and the developer carrier 6 is completed.

In order for the overcoat layer 17 to be easily peeled off from the inner surface of the mold material 100 during the above-described mold release, it is important that the mold material 1°Ol, especially its inner surface, be made of a material with high mold releasability. Examples of materials with high mold release properties include fluorine-containing resins, silicone resins, especially RTV silicone rubber, and olefin resins such as polyethylene and polypropylene.6 If the overcoat layer 17 is made of a lipophilic resin, Water-soluble resins such as polyvinyl alcohol can also be advantageously used as mold release agents.

As a specific example of the structure of the mold material 100, the mold material 100 is made by coating the inner surface of a cylindrical body made of metal such as nickel produced by electroforming with the above-mentioned material with high mold releasability.
can be used.

Another example is polytetrafluoroethylene (P
TFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FE)
P), tetrafluoroethylene-ethylene copolymer (E
The cylindrical mold material 100 can also be constructed by heat-shrinking a heat-shrinkable tube made of a fluorine-containing resin such as TFE into a highly precisely formed cylindrical mold, and then extracting the tube from the mold.

As shown in FIG. 3(d), when the developer carrier is released from the mold material 100, if the mold material 100 is a highly non-adhesive heat shrinkable tube as described above, the developer carrier is removed from the mold material 100. Prior to mold release, by mechanically deforming the mold material 100 made of a tube holding the mold material, the inner surface of the mold material 100 and the overcoat layer 17 can be peeled off, and the developer carrier can be easily removed from the mold material. It can be extracted from 100.

In addition, when the mold material 100 is a metal cylinder coated with a mold release material, the inner surface of the mold material and the overcoat layer 1
By partially peeling 7 and applying air flow to the peeled portion, the inner surface of the mold material and the overcoat layer 17 can be completely peeled off, and the mold can be easily released.

Furthermore, when the aforementioned tube is used as the mold material and the material is relatively inexpensive, such as polyethylene, it is also possible to destroy the mold material itself and release the developer carrier from the mold material.

In addition, FIG. 3(b) during the manufacturing process of the above-mentioned developer carrier
In the process, the adhesive 15 was applied to the mold material side, but the adhesive 15 was applied in advance around the soft elastic layer 13 of the first elastic roll 14, so that the elastic layer 13
The elastic cylinder layer 16 may be bonded to the elastic cylinder layer 16.

Since the surface of the overcoat layer of the developer carrier produced by the method described above is the surface peeled from the mold material 100, it can be made into an extremely smooth surface, and a uniform toner layer can be supported thereon. , high quality images can be formed. Furthermore, since the manufacturing method is simple, the cost of the developer carrier can be reduced.

The developer carrier according to the present invention can be used not only in electronic copying machines but also in developing devices in various other image forming apparatuses.

〔Effect of the invention〕

The developer carrier manufactured by the method according to the present invention can achieve a high degree of softening due to its soft elastic layer, and can also smooth the surface of the overcoat layer with high precision, improving image quality, especially full-color images. Uniformity and high gradation, which are important for Furthermore, the rotational torque of the developer carrier can be reduced, and the entire apparatus can be made smaller.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a developing device equipped with a developer carrier according to an embodiment of the present invention, FIG. 2 is a sectional view of the developer carrier, and FIGS. 3(a) to 3(d) are its fabrication. It is an explanatory diagram showing a process. 3...Non-magnetic one-component developer 6...Developer carrier 13...Soft elastic layer 16...Elastic cylinder layer 100...Shape 11...Shaft 14...Elastic body Roll 17...overcoat layer

Claims (1)

[Claims] In a method for manufacturing a developer carrier that visualizes an electrostatic latent image formed on a latent image carrier by a non-magnetic one-component developer carried on the outer peripheral surface, an overcoat layer is formed on the inner surface of a cylindrical shape material. , an elastic roll in which elastic cylinder layers made of rubber material are sequentially laminated and a soft elastic layer made of foam is integrally provided around the shaft is placed inside the mold material in which the overcoat layer and the elastic cylinder layer are laminated. A method for manufacturing a developer carrier, comprising: arranging the soft elastic body layer, adhering the soft elastic body layer and the elastic cylinder layer, and releasing the shaft, the soft elastic body layer, the elastic cylinder layer, and the overcoat layer from the mold material.