Abstract: This invention provides a process for producing a conductive rubber roller having small aspect ratios of inner and outer diameters, having a stable measure of its inner diameter, having uniform cell distribution and being free from non-uniformity of hardness and electrical resistance in the peripheral direction. The process has a step of continuously extruding a tube composed of a specific unvulcanized rubber composition from a rubber extruder in a microwave vulcanizing unit, and a step of foaming and vulcanizing the tube by using a microwave irradiator having a microwave irradiation zone 4 m or less in length while being transported at given speed. The foamed rubber tube has an inner diameter 20 to 35% smaller than the outer diameter of the conductive core material over the whole region in the lengthwise direction, and the conductive core material is press-fitted into the foamed rubber tube without using any adhesive.

Abstract: This invention provides a process for producing a conductive rubber roller having small aspect ratios of inner and outer diameters, having a stable measure of its inner diameter, having uniform cell distribution and being free from non-uniformity of hardness and electrical resistance in the peripheral direction. The process has a step of continuously extruding a tube composed of a specific unvulcanized rubber composition from a rubber extruder in a microwave vulcanizing unit, and a step of foaming and vulcanizing the tube by using a microwave irradiator having a microwave irradiation zone 4 m or less in length while being transported at given speed. The foamed rubber tube has an inner diameter 20 to 35% smaller than the outer diameter of the conductive core material over the whole region in the lengthwise direction, and the conductive core material is press-fitted into the foamed rubber tube without using any adhesive.

Abstract: This invention provides a process for producing a conductive rubber roller having small aspect ratios of inner and outer diameters, having a stable measure of its inner diameter, having uniform cell distribution and being free from non-uniformity of hardness and electrical resistance in the peripheral direction. The process has a step of continuously extruding a tube composed of a specific unvulcanized rubber composition from a rubber extruder in a microwave vulcanizing unit, and a step of foaming and vulcanizing the tube by using a microwave irradiator having a microwave irradiation zone 4 m or less in length while being transported at given speed. The foamed rubber tube has an inner diameter 20 to 35% smaller than the outer diameter of the conductive core material over the whole region in the lengthwise direction, and the conductive core material is press-fitted into the foamed rubber tube without using any adhesive.

Abstract: This invention provides a process for producing a conductive rubber roller having small aspect ratios of inner and outer diameters, having a stable measure of its inner diameter, having uniform cell distribution and being free from non-uniformity of hardness and electrical resistance in the peripheral direction. The process has a step of continuously extruding a tube composed of a specific unvulcanized rubber composition from a rubber extruder in a microwave vulcanizing unit, and a step of foaming and vulcanizing the tube by using a microwave irradiator having a microwave irradiation zone 4 m or less in length while being transported at given speed. The foamed rubber tube has an inner diameter 20 to 35% smaller than the outer diameter of the conductive core material over the whole region in the lengthwise direction, and the conductive core material is press-fitted into the foamed rubber tube without using any adhesive.

Abstract: A process for producing a conductive rubber roller having a conductive core material and a rubber layer provided thereon. The rubber layer contains at least acrylonitrile rubber, epichlorohydrin rubber and a blowing agent, and has a gas generation rate of from 2 ml/g·min to 4 ml/g·min at 170° C. to 230° C. The process has a vulcanizing and foaming step of vulcanizing and foaming the rubber layer by using a microwave vulcanizing furnace which provides hot air and irradiation with microwaves. A temperature of a heating atmosphere in the microwave vulcanizing furnace in the vulcanizing and foaming step is so controlled that a ratio of initial vulcanizing time T10 to initial foaming time Tp10, T10/Tp10, of the rubber layer is from 1 or more to less than 3 and the T10 is within 90 seconds.

Abstract: This invention provides a process for producing a conductive rubber roller having small aspect ratios of inner and outer diameters, having a stable measure of its inner diameter, having uniform cell distribution and being free from non-uniformity of hardness and electrical resistance in the peripheral direction. The process has a step of continuously extruding a tube composed of a specific unvulcanized rubber composition from a rubber extruder in a microwave vulcanizing unit, and a step of foaming and vulcanizing the tube by using a microwave irradiator having a microwave irradiation zone 4 m or less in length while being transported at given speed. The foamed rubber tube has an inner diameter 20 to 35% smaller than the outer diameter of the conductive core material over the whole region in the lengthwise direction, and the conductive core material is press-fitted into the foamed rubber tube without using any adhesive.

Abstract: A conductive rubber roller and transfer roller whose resistance value is easily controlled and which lowers contamination of a charged member and has excellent electric variability and compressive permanent set is provided at low cost. There is provided a conductive rubber roller for use in an electrophotographic process, wherein a rubber component of the conductive rubber roller has at least acrylonitrile butadiene rubber whose acrylonitrile content is 15% by mass to 25% by mass (both inclusive) and weight average molecular weight (Mw) is 500,000 to 1,000,000 (both inclusive), and epichlorohydrin type rubber whose ethylene oxide content is not less than 70% by mole to less than 90% by mole; and the acrylonitrile butadiene rubber is contained in an amount of 5 parts by mass to 80 parts by mass (both inclusive) in 100 parts by mass of the rubber component.

Abstract: A process produces a conductive rubber roller having small aspect ratios of inner and outer diameters, having a stable measure of its inner diameter, having uniform cell distribution and being free from non uniformity of hardness and electrical resistance in the peripheral direction. The process has a step of continuously extruding a tube composed of a specific unvulcanized rubber composition from a rubber extruder in a microwave vulcanizing unit, and a step of foaming and vulcanizing the tube by using a microwave irradiator having a microwave irradiation zone 4 m or less in length while being transported at given speed. The foamed rubber tube has an inner diameter 20 to 35% smaller than the outer diameter of the conductive core material over the whole region in the lengthwise direction, and the conductive core material is press fitted into the foamed rubber tube without using any adhesive.

Abstract: This invention provides a process for producing a conductive rubber roller having small aspect ratios of inner and outer diameters, having a stable measure of its inner diameter, having uniform cell distribution and being free from non-uniformity of hardness and electrical resistance in the peripheral direction. The process has a step of continuously extruding a tube composed of a specific unvulcanized rubber composition from a rubber extruder in a microwave vulcanizing unit, and a step of foaming and vulcanizing the tube by using a microwave irradiator having a microwave irradiation zone 4 m or less in length while being transported at given speed. The foamed rubber tube has an inner diameter 20 to 35% smaller than the outer diameter of the conductive core material over the whole region in the lengthwise direction, and the conductive core material is press-fitted into the foamed rubber tube without using any adhesive.

Abstract: A blade member manufacturing process using no mold and a developer quantity control blade manufacturing process using this blade member are disclosed in which a material for the blade member is extruded onto a charge control face face-transferring sheet in a uniform thickness, and solidified to form a layer, and the layer is cut into the shape of a blade member.

Abstract: A blade member manufacturing process using no mold and a developer quantity control blade manufacturing process using this blade member are disclosed in which a material for the blade member is extruded onto a charge control face face-transferring sheet in a uniform thickness, and solidified to form a layer, and the layer is cut into the shape of a blade member.

Abstract: A blade member manufacturing process using no mold and a developer quantity control blade manufacturing process using this blade member are disclosed in which a material for the blade member is extruded onto a charge control face face-transferring sheet in a uniform thickness, and solidified to form a layer, and the layer is cut into the shape of a blade member.