WO2013067933A1

WO2013067933A1 - Developing roller

Info

Publication number: WO2013067933A1
Application number: PCT/CN2012/084218
Authority: WO
Inventors: 苏健强; 周巍峙
Original assignee: 珠海天威飞马打印耗材有限公司
Priority date: 2011-11-11
Filing date: 2012-11-07
Publication date: 2013-05-16
Also published as: CN102375378B; CN102375378A

Abstract

A developing roller, including a core shaft (1), an elastic layer provided on the core shaft (1) and a surface layer (4) provided on the elastic layer. The elastic layer includes two layers, i.e. an inner layer and an outer layer, of conductive elastomer (2, 3). An adhesive layer (5) is provided between the core shaft (1) and the inner-layer conductive elastomer (2). The surface layer (4) is attached to the outer surface of the outer-layer conductive elastomer (3).

Description

Developing roller

Technical field

The present invention relates to a developing roller for a laser image forming apparatus. The present application claims priority to Chinese Patent Application No. 20111035681, the entire disclosure of which is incorporated herein by reference.

Background technique

Laser printer is one of the most widely used external computer output devices. It uses the physical and chemical principles of light, electricity and heat to output text or images through interaction. The basic process can be divided into seven steps: charging, exposure, development, transfer, fixing, cleaning, and power-saving. First, the surface of the photosensitive drum is uniformly charged by the charging roller. The laser scanner emits a modulated laser light containing image information to the photosensitive drum to form an electrostatic latent image corresponding to the image to be reproduced on the surface of the photosensitive drum. At the same time, the developing roller rotates, the toner between the developing roller and the powder discharging knife is charged by the rotating friction, and the charged carbon powder is evenly distributed on the developing roller due to the pressure of the powder knife, and the developing roller rotates to the photosensitive drum. The charged toner of the contact portion is transferred to the surface of the photosensitive drum by an electric field force to convert the electrostatic latent image into a visible image. With the rotation of the photosensitive drum and the positive voltage applied to the back surface of the recording medium such as paper by the transfer roller, the negatively charged toner forming a visible image on the surface of the photosensitive drum is attracted, and the toner is formed. The image is transferred to a recording medium such as paper. Subsequently, the fixing unit formed by the heating roller and the pressure roller is introduced, and the toner particles are melted into the fibers of the recording medium under the action of heat and pressure, so that the visible image formed by the carbon powder is completely cured on the recording medium. Such a basic imaging action is completed.

In the printing process, in order to achieve high-quality printing results, the developing roller is essential. The development of the existing developing roller has to choose a special conductive material as the developing roller substrate because of its uniform electrical resistivity requirement. This kind of material is particularly expensive and has an upward trend due to the rise of international raw materials, while the price of the existing developing roller market is declining, so high-quality and low-cost design and development has become a top priority.

technical problem

The technical problem to be solved by the present invention is to reduce the manufacturing cost of the developing roller under the premise of ensuring print quality.

Technical solution

In order to solve the above technical problems, the present invention adopts the following technical solution: designing a developing roller including a mandrel, an elastic layer disposed on the mandrel, and a surface layer disposed on the elastic layer, the elasticity The layer comprises at least two layers of electrically conductive elastomer.

Preferably, the elastic layer comprises an inner layer and an outer layer of a total of two layers of conductive elastomer, the surface layer being attached to an outer surface of the outer layer of the conductive elastomer. Preferably, an adhesive layer is disposed between the mandrel and the inner conductive elastomer. The adhesive layer helps the mandrel and the inner conductive elastomer to be bonded together, so that no matter what the condition of the product, the two will not be separated from each other, thereby ensuring stable electrical conductivity and required rotation of the product during printing. The effective transmission does not occur with the relative rotation of the inner conductive elastomer and the mandrel, ensuring the effectiveness of printing.

Preferably, the cross-sectional outer contour shape of the inner layer conductive elastomer may be circular, elliptical, regular polygon, scalloped, square tooth or pointed tooth or the like. The circular shape can ensure the uniformity of the electrical properties of the outer circle; the elliptical shape can eliminate the grinding process of the inner conductive elastic body forming and reduce the cost; the advantages of the scalloped shape, the square tooth shape and the pointed tooth shape are the two layers of elasticity. The contact surface between the bodies is larger and in an engaged state, which is advantageous for the inner and outer elastic bodies to be effectively adhered without the adhesive, and it is not easy to separate the layers, thereby ensuring effective rotation during printing. Of course, the two-layer elastomer can be bonded without adhesive, and it is considered from the formulation. It is characterized in that one or two or more of the material components of the two-layer elastomer have the same rubber, because in the presence of the same rubber, The joint surface must have a chemical bonding interface for a more stable joint.

Preferably, the outer conductive elastomer has a thickness of 0.5 mm to 2.5 mm.

Preferably, the hardness of the inner layer conductive elastomer is equal to or greater than the hardness of the outer layer conductive elastomer, and the inner layer conductive elastomer has a resistance value smaller than that of the outer layer conductive elastomer. The outer conductive elastomer needs to provide a certain range and stable and reliable electrical conductivity, and also needs sufficient mechanical deformation capability, so that the outer conductive elastic body has a low hardness to ensure deformation thereof, thereby ensuring printing effect.

Preferably, among the elastic layers, the volume percentage of the inner layer conductive elastomer is 51% to 89%, and the volume percentage of the outer layer conductive elastomer is 11% to 49%, such a ratio can Effectively reduce production difficulty and material costs.

The preparation material of the inner layer conductive elastic body 2 is as follows (parts by weight): 30-90 parts of nitrile rubber; 5-55 parts of cis-butadiene rubber; 5-30 parts of chlorohydrin rubber; 5-20 parts of strong conductive carbon black 20-50 parts of ordinary carbon black; 5-30 parts of calcium carbonate; 5-30 parts of plasticizer; 0.5-2.5 parts of vulcanizing agent; 0.5-1.5 parts of accelerator TMTM; accelerator CZ 0.8-2 parts; 2-7 parts of zinc oxide; 1-3 parts of stearic acid; antioxidant RD 1-2 servings. Such a formulation can ensure the adhesion between the inner layer and the outer layer; the strong conductive carbon black is used to ensure the conductive effect; the addition of a certain amount of calcium carbonate is to reduce the cost in consideration of the plasticizer; the plasticizer can appropriately adjust the hardness; The agent is general sulfur; two kinds of accelerators are additives for promoting vulcanization; zinc oxide and stearic acid can mutually activate the vulcanization effect, increase the crosslinking density and improve the properties of the rubber compound; and the antioxidant prevents oxidation during processing. Degradation and subsequent anti-aging effects.

The raw material of the outer conductive elastomer 3 is prepared as follows (parts by weight): 5-50 parts of nitrile rubber; 30-95 parts of chlorohydrin rubber; 3-10 parts of weak conductive carbon black; 15-70 parts of ordinary carbon black Calcium carbonate 10-40 parts; paraffin wax 1-5 parts; softener liquid butyronitrile 3-20 parts; vulcanizing agent 0.5-1.5 parts; accelerator TMTM 0.3-1.5 parts; accelerator CZ 0.5-2.0 parts; zinc oxide 2-7 parts; 1-5 parts of stearic acid; antioxidant RD 1-2 servings. The nitrile rubber can provide the material with certain wear resistance. The chlorohydrin glue has good resistance to high and low temperature and ozone resistance, and the rubber itself has certain ion conductivity, which is favorable for the uniformity of conductivity of the material. The outer layer conductivity is a semi-conductive material that requires a certain conductivity, so only a weakly conductive carbon black can be added in a certain amount. The addition of carbon black can increase the strength of the rubber, and calcium carbonate is added as a filler to reduce the cost. The above other ingredients are described above.

Further, the elastic layer comprises a total of three layers of conductive elastomers of the inner layer, the middle layer and the outer layer.

Beneficial effect

The developing roller of the present invention comprises at least two layers of conductive elastomers, wherein the inner conductive elastomer can be made of a less expensive conductive elastic material, and the outer conductive elastomer is made of a special one, which is more expensive. The rubber material can ensure uniform volumetric conductivity and uniform surface conductivity, so that the printing effect remains unchanged. This design can take into account both the low price and the stable quality.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a developing roller according to a first embodiment of the present invention.

Figure 2 is a plan view of the developing roller shown in Figure 1.

Fig. 3 is a cross-sectional view taken along line A-A of Fig. 2;

Figure 4 is a cross-sectional view showing a developing roller of a second embodiment of the present invention.

Figure 5 is a cross-sectional view of a developing roller in accordance with a third embodiment of the present invention.

Figure 6 is a cross-sectional view showing a developing roller of a fourth embodiment of the present invention.

Figure 7 is a cross-sectional view showing a developing roller of a fifth embodiment of the present invention.

Figure 8 is a cross-sectional view showing a developing roller of a sixth embodiment of the present invention.

Fig. 9 is a list of preparation raw material formulations of the inner layer conductive elastomers according to the first to sixth embodiments of the present invention.

Fig. 10 is a list of recipes for preparing an outer layer of an electrically conductive elastomer according to the first to sixth embodiments of the present invention.

Embodiments of the invention

Embodiment 1

1 to 3 show a developing roller according to the present invention comprising a mandrel 1 made of a conductive metal and an inner layer of conductive elastomer 2, an outer layer of conductive elastomer 3 which are sequentially stacked on the mandrel 1. And a surface layer 4 attached to the outer layer conductive elastic body 3, and an adhesive layer 5 is provided between the inner layer conductive elastic body 2 and the mandrel 2.

The inner layer conductive elastic body 2 is prepared according to the formula of the first embodiment recorded in FIG. 9 (in parts by weight), and the rubber is mixed, and the rubber compound can be selected from an open mill or an internal mixer. machine. The kneaded compound was placed in a mold after standing for one day, and the molding temperature (mold temperature) was 160 ° C for 5 to 30 minutes, which was 8 minutes in this example. The cross-sectional outer contour shape of the inner conductive elastic body 2 may be a circular shape, an elliptical shape, a regular polygonal shape, a scalloped shape, a square tooth shape or a pointed tooth shape, and the like, which is advantageous for the shape design of the inner and outer conductive elastic bodies. This embodiment adopts a circular shape.

The outer conductive elastomer 3 is prepared according to the formulation of the first embodiment recorded in FIG. 10 (diluted by weight), rubberized, and the compounded rubber is allowed to stand for one day, and the inner conductive elastic body 2 is semi-finished. It is placed in a T-shaped or Y-shaped machine head for extrusion extrusion, and the forming method can also be formed by compression molding. Then, it is placed in a vulcanization tank for vulcanization. The vulcanization tank temperature is 160 ° C, the tank pressure is 0.2 MPa-0.8 MPa, and the vulcanization time is 10 minutes to 30 minutes. The conditions used in this example are the vulcanization tank pressure of 0.5 MPa and the vulcanization time of 15 minutes. Then, it is placed in the oven for secondary sulfurization, the temperature is 150 ° C, and the time is 4 hours. After the second sulfur is added, the product is cut off at the edge and then ground to the specified size. The grinding can be carried out with a wide grinding wheel or a narrow grinding wheel. The grinding is carried out left and right. In this implementation, the grinding is performed by a narrow grinding wheel. The surface roughness of the ground product is usually characterized by Ra, and the value is between 0.5 μ and 2 μ, preferably between 0.7 μ and 1.5 μ, and the surface roughness of the present embodiment is 0.9 μ.

The final process is surface coating treatment. The surface coating can be carried out by dip coating or spraying. The implementation is sprayed. The coating is semi-conductive coating. The coating resistance is 106Ω-109Ω and the coating thickness is 2μ. -50 μ, the coating thickness of this example was 6 μ, and the product one was obtained.

In the elastic layer of the present embodiment, the outer layer conductive elastic body 3 has a thickness of 2.5 mm, the inner layer conductive elastic body 2 has a volume percentage content of 51%, and the outer layer conductive elastic body 3 has a volume percentage content of 49%. The inner layer conductive elastic body 2 has a hardness value of 64 and a resistance value of 0.001 to 0.01. MΩ; the outer conductive elastomer 3 has a hardness value of 48 and a resistance value of 0.2 MΩ.

Implementation two

The weight ratio of the second embodiment in the formula table shown in FIG. 9 and FIG. 10 is selected, and the method of the first embodiment is used for rubber compounding and forming. The cross-sectional outer contour shape of the inner layer conductive elastic body 2 semi-finished product of the present embodiment is elliptical. The major axis of the ellipse is 1-5 mm smaller than the outer diameter of the product, the minor axis is 1-5 mm smaller than the outer diameter of the product, and the axial length ratio is between 1 and 1.3, preferably 1.05. The obtained semi-finished product is extruded and formed as described in the first embodiment, and then placed in a vulcanization tank for vulcanization and grinding. The outer conductive elastic body 3 of the long-axis end has a thickness of 1.2 mm, and the surface coating, the coarse grinding degree and the coating thickness are the same as that of the first embodiment. , get product two.

In the elastic layer of the present embodiment, the volume percentage of the inner layer conductive elastic body 2 was 72%, and the volume percentage of the outer layer conductive elastic body 3 was 28%. The inner layer conductive elastic body 2 has a hardness value of 62 and a resistance value of 0.001 to 0.01. MΩ; the outer conductive elastomer 3 has a hardness value of 50 and a resistance value of 0.22 MΩ.

Implementation three

The weight ratio of the third embodiment in the formula table shown in FIG. 9 and FIG. 10 is used to prepare the product 3 according to the method described in the first embodiment. The cross-sectional outer contour shape of the inner layer conductive elastic body 2 semi-finished product of the embodiment is selected from a sharp tooth shape. , the outer conductive elastic body 3 has a thickness of 0.5 Mm. In the elastic layer of the present embodiment, the inner layer conductive elastic body 2 has a volume percentage content of about 83%, and the outer layer conductive elastic body 3 has a volume percentage content of about 17%. The inner layer conductive elastic body 2 has a hardness value of 62 and a resistance value of 0.001 to 0.01. MΩ; the outer conductive elastomer 3 has a hardness value of 51 and a resistance value of 0.25 MΩ.

Implementation four

The product 4 is prepared according to the method described in the first embodiment, and the cross-sectional outer contour shape of the inner layer conductive elastic body 2 semi-finished product of the embodiment is selected from a circular tooth shape. The outer conductive elastic body 3 has a thickness of 1.0 mm. In the elastic layer of the present embodiment, the volume percentage of the inner layer conductive elastic body 2 was 76%, and the volume percentage of the outer layer conductive elastic body 3 was 24%. The inner layer conductive elastic body 2 has a hardness value of 63 and a resistance value of 0.001 to 0.01. MΩ; the outer conductive elastomer 3 has a hardness value of 49 and a resistance value of 0.1 MΩ.

Implementation five

The weight ratio of the fifth embodiment in the formula table shown in FIG. 9 and FIG. 10 is used to prepare the product 5 according to the method of the first embodiment. The cross-sectional outer contour shape of the inner layer conductive elastic body 2 semi-finished product of the embodiment is selected from the square tooth shape. The outer conductive elastic body 3 has a thickness of 1.8 mm. In the elastic layer of the present embodiment, the inner layer conductive elastic body 2 has a volume percentage content of 54%, and the outer layer conductive elastic body 3 has a volume percentage content of 46%. The inner layer conductive elastic body 2 has a hardness value of 61 and a resistance value of 0.001 to 0.01. MΩ; the outer conductive elastomer 3 has a hardness value of 51 and a resistance value of 0.18 MΩ.

Implementation six

The product 6 is manufactured according to the method described in the first embodiment, and the cross-sectional outer contour shape of the semi-finished inner conductive elastic body 2 of the present embodiment is a regular polygon. The outer conductive elastic body 3 has a thickness of 0.8 Mm. In the elastic layer of the present embodiment, the volume percentage of the inner layer conductive elastic body 2 was 74%, and the volume percentage of the outer layer conductive elastic body 3 was 26%. The inner layer conductive elastic body 2 has a hardness value of 61 and a resistance value of 0.001 to 0.01. MΩ; the outer conductive elastomer 3 has a hardness value of 52 and a resistance value of 0.21 MΩ.

The above is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept, for example, the elasticity. The layer is not limited to two layers, and may also comprise three layers of conductive elastomers of the inner layer, the middle layer and the outer layer, and even more layers. The cross-sectional outer contour shape of the inner conductive elastomer is not limited to the shape exemplified in the above embodiment; the thickness of the outer conductive elastic body is not limited to 0.5 mm. ~2.5mm.

Industrial applicability

The developing roller of the present invention comprises at least two layers of conductive elastomers, wherein the inner conductive elastomer can be made of a less expensive conductive elastic material, and the outer conductive elastomer is made of a relatively expensive conductive rubber having special properties. The material can ensure uniform volumetric conductivity and uniform surface conductivity, so that the printing effect remains unchanged. This design can take into account both the low price and the stable quality. Therefore, the developing roller of the present invention has industrial applicability.

Claims

A developing roller comprising a mandrel, an elastic layer disposed on the mandrel, and a surface layer disposed on the elastic layer, wherein the elastic layer comprises at least two layers of conductive elastomer.
The developing roller according to claim 1, wherein said elastic layer comprises an inner layer and an outer layer of a total of two layers of electrically conductive elastomer, said surface layer being attached to an outer surface of said outer layer of electrically conductive elastomer.
The developing roller according to claim 2, wherein an adhesive layer is provided between the mandrel and the inner layer of the electrically conductive elastomer.
The developing roller according to claim 2, wherein the inner conductive elastic body has a cross-sectional outer contour shape of a circular shape, an elliptical shape, a regular polygonal shape, a circular tooth shape, a square tooth shape or a pointed tooth shape.
The developing roller according to claim 2, wherein said outer conductive elastomer has a thickness of from 0.5 mm to 2.5 mm.
The developing roller according to claim 2, wherein said inner conductive elastomer has a hardness equal to or greater than a hardness of said outer conductive elastic body, and said inner conductive elastic member has a smaller electrical resistance than said outer conductive roller. The resistance value of the layer of conductive elastomer.
The developing roller according to claim 2, wherein in said elastic layer, said inner conductive elastomer has a volume percentage of 51% to 89%, and said outer conductive elastomer has a volume percentage content. It is 11%~49%.
The developing roller according to claim 2, wherein the raw material of the inner layer conductive elastomer is formulated as follows (parts by weight): 30-90 parts of nitrile rubber; 5-55 parts of butadiene rubber; chlorohydrin rubber 5-30 parts; strong conductive carbon black 5-20 parts; ordinary carbon black 20-50 parts; calcium carbonate 5-30 parts; plasticizer 5-30 parts; vulcanizing agent 0.5-2.5 parts; accelerator TMTM 0.5-1.5 parts; accelerator CZ 0.8-2 parts; zinc oxide 2-7 parts; stearic acid 1-3 parts; antioxidant RD 1-2 parts.
The developing roller according to claim 2, wherein the raw material of the outer conductive elastomer is formulated as follows (parts by weight): 5-50 parts of nitrile rubber; 30-95 parts of chlorohydrin rubber; weakly conductive carbon 3-10 parts black; 15-70 parts of ordinary carbon black; calcium carbonate 10-40 parts; paraffin wax 1-5 parts; softener liquid butyronitrile 3-20 parts; vulcanizing agent 0.5-1.5 parts; accelerator TMTM 0.3-1.5 parts; accelerator CZ 0.5-2.0 parts; zinc oxide 2-7 parts; 1-5 parts of stearic acid; 1-2 parts of antioxidant RD.
The developing roller according to claim 1, wherein said elastic layer comprises a total of three layers of an electrically conductive elastomer of an inner layer, a middle layer and an outer layer.