Abstract: A rubber composition capable of forming a foam such as a roller main body which has a low rubber hardness and is soft in a state in which an average cell diameter thereof is small is provided. The rubber composition includes NBR whose Mooney viscosity is 15 to 50 having a proportion being 10 parts by mass or more in 100 parts by mass of the total amount of rubber, epichlorohydrin rubber whose Mooney viscosity is 5 to 35 having a proportion being 10 parts by mass or more in 100 parts by mass of the total amount of rubber, and 10 parts by mass or less of carbon black and 7 parts by mass or less of a foaming agent with respect to 100 parts by mass of the total amount of rubber, and has a Mooney viscosity of 35 or less.

Abstract: An electrically conductive rubber composition is provided, which is usable for production of a transfer roller of a highly flexible foam satisfying requirements for cost reduction and weight reduction and having smaller foam cell diameters and, hence, ensuring higher-quality image formation with smaller environment-dependent variations in roller resistance. A transfer roller produced from the electrically conductive rubber composition, a production method for the transfer roller, and an image forming apparatus including the transfer roller are also provided. The electrically conductive rubber composition contains a rubber component including SBR and/or BR, EPDM and epichlorohydrin rubber, a crosslinking component, and 4 to 6 parts by mass of a foaming agent and 1.5 to 2.7 parts by mass of a foaming assisting agent based on 100 parts by mass of the rubber component.

Abstract: An inventive electrically conductive rubber composition contains: a rubber component including SBR and/or NBR, and 20 to 30 parts by mass of epichlorohydrin rubber based on 100 parts by mass of the overall rubber component; a crosslinking component; a foaming component; and a potassium salt of an anion having a fluoro group and a sulfonyl group in its molecule, the potassium salt being present in a proportion of not less than 0.01 part by mass and not greater than 1 part by mass based on 100 parts by mass of the overall rubber component. An inventive transfer roller (1) includes a roller body (2) formed from the electrically conductive rubber composition.

Abstract: A rubber composition capable of forming a foam such as a roller main body which has a low rubber hardness and is soft in a state in which an average cell diameter thereof is small is provided. The rubber composition includes NBR whose Mooney viscosity is 15 to 50 having a proportion being 10 parts by mass or more in 100 parts by mass of the total amount of rubber, epichlorohydrin rubber whose Mooney viscosity is 5 to 35 having a proportion being 10 parts by mass or more in 100 parts by mass of the total amount of rubber, and 10 parts by mass or less of carbon black and 7 parts by mass or less of a foaming agent with respect to 100 parts by mass of the total amount of rubber, and has a Mooney viscosity of 35 or less.

Abstract: A rubber composition in which a transfer roller with lower resistance than in the related art is able to be formed without increasing a blending ratio of epichlorohydrin rubber, a transfer roller including the rubber composition, and an image forming apparatus having the transfer roller incorporated therein are provided. The rubber composition is obtained by blending rubbers including at least one of NBR, SBR, and BR and epichlorohydrin rubber with a crosslinking component, a foaming component, and 3 to 50 parts by mass aluminum silicate with respect to 100 parts by mass of the total amount of rubbers. A transfer roller includes a roller main body formed by extrusion-molding the rubber composition in a tubular shape and foaming and crosslinking the rubber composition. The image forming apparatus includes the transfer roller incorporated therein.

Abstract: An inventive electrically conductive rubber composition contains: a rubber component including SBR and/or NBR, and 20 to 30 parts by mass of epichlorohydrin rubber based on 100 parts by mass of the overall rubber component; a crosslinking component; a foaming component; and a potassium salt of an anion having a fluoro group and a sulfonyl group in its molecule, the potassium salt being present in a proportion of not less than 0.01 part by mass and not greater than 1 part by mass based on 100 parts by mass of the overall rubber component. An inventive transfer roller (1) includes a roller body (2) formed from the electrically conductive rubber composition.

Abstract: An electrically conductive rubber composition is provided, which is usable for production of a transfer roller of a highly flexible foam satisfying requirements for cost reduction and weight reduction and having smaller foam cell diameters and, hence, ensuring higher-quality image formation with smaller environment-dependent variations in roller resistance. A transfer roller produced from the electrically conductive rubber composition, a production method for the transfer roller, and an image forming apparatus including the transfer roller are also provided. The electrically conductive rubber composition contains a rubber component including SBR and/or BR, EPDM and epichlorohydrin rubber, a crosslinking component, and 4 to 6 parts by mass of a foaming agent and 1.5 to 2.7 parts by mass of a foaming assisting agent based on 100 parts by mass of the rubber component.

Abstract: An inventive transfer roller (1) is made of a foam formed from an electrically conductive rubber composition containing an electrically conductive rubber, a crosslinking component, and a foaming agent including OBSH and 0.25 to 2.5 parts by mass of sodium hydrogen carbonate based on 1 part by mass of OBSH, and has an Asker-C hardness of not lower than 25 degrees and not higher than 35 degrees and an average foam cell diameter of not greater than 120 ?m. Therefore, the transfer roller is flexible with a lower rubber hardness, and has smaller foam cell diameters. An inventive production method includes the steps of: forming the electrically conductive rubber composition into a tubular body; and maintaining the tubular body at a temperature of not lower than 120° C. and not higher than 140° C. to foam the rubber by a single-stage foaming process.

Abstract: A toner supply roller (1) is produced by preparing a rubber composition which contains a rubber component including an epichlorohydrin rubber and a butadiene rubber, a crosslinking component and a foaming component and, while extruding the rubber composition into a tubular body, continuously foaming and crosslinking the rubber composition of the tubular body by a continuous crosslinking apparatus including a microwave crosslinking device and a hot air crosslinking device. An image forming apparatus incorporates the toner supply roller (1).

Abstract: A rubber foam tube (5) is produced by extruding a rubber composition into a tubular body (4) and feeding the tubular body (4) in an elongated state without cutting to pass the tubular body (4) through a microwave crosslinking device (8) and then through a hot air crosslinking device (9) for continuously foaming and crosslinking the rubber composition. At this time, a ratio V2/V1 between a speed V2 at which the tubular body (4) passes through the hot air crosslinking device (9) and a speed V1 at which the tubular body (4) passes through the microwave crosslinking device (8) is not less than 1.0 and not greater than 1.6.

Abstract: An electrically conductive rubber composition which can be efficiently and sufficiently foamed and crosslinked by means of a continuous crosslinking apparatus including a microwave crosslinking device and a hot air crosslinking device without generation of ammonia and carbon monoxide. The electrically conductive rubber composition comprises a rubber component, a crosslinking component for crosslinking the rubber component, and a foaming component including sodium hydrogen carbonate and citric acid.

Abstract: A toner supply roller is provided which has the most uniform and greatest possible foam cell diameters and a lower hardness particularly even in a lower-temperature and lower-humidity environment as compared with the conventional art and is less liable to suffer from imaging failure such as uneven density and white streaks. An image forming apparatus employing the toner supply roller is also provided. The toner supply roller (1) is produced by preparing a rubber composition which contains a rubber component including an epichlorohydrin rubber and an acrylonitrile butadiene rubber, an electrically conductive carbon black, a crosslinking component and a foaming component and, while extruding the rubber composition into a tubular body, continuously foaming and crosslinking the rubber composition of the tubular body by a continuous crosslinking apparatus including a microwave crosslinking device and a hot air crosslinking device. The image forming apparatus incorporates the toner supply roller (1).

Abstract: An electrically conductive rubber composition is provided, which comprises a rubber component including an SBR, an EPDM and an epichlorohydrin rubber, a crosslinking component and an azodicarbonamide foaming agent having an average particle diameter of 3 to 11 ?m. The azodicarbonamide foaming agent is blended in a proportion of 0.5 to 8 parts by mass based on 100 parts by mass of the overall rubber component. A transfer roller (1) is produced by extruding the electrically conductive rubber composition into an elongated tubular body, and continuously feeding out the tubular body in the elongated state without cutting the tubular body to continuously pass the tubular body through a microwave crosslinking device and a hot air crosslinking device to continuously foam and crosslink the tubular body.

Abstract: A toner supply roller (1) is produced by preparing a rubber composition which contains at least a rubber component including at least an epichlorohydrin rubber and a styrene butadiene rubber, a crosslinking component and a foaming component and, while extruding the rubber composition into a tubular body, continuously foaming and crosslinking the rubber composition of the tubular body by a continuous crosslinking apparatus including a microwave crosslinking device and a hot air crosslinking device.

Abstract: A toner supply roller (1) is produced by preparing a rubber composition which contains a rubber component including an epichlorohydrin rubber and a chloroprene rubber, an electrically conductive carbon black, a crosslinking component and a foaming component and, while extruding the rubber composition into a tubular body, continuously foaming and crosslinking the rubber composition of the tubular body by a continuous crosslinking apparatus including a microwave crosslinking device and a hot air crosslinking device. An image forming apparatus incorporates the toner supply roller (1).

Abstract: A toner supply roller (1) is produced by preparing a rubber composition which contains a rubber component including an epichlorohydrin rubber and a butadiene rubber, a crosslinking component and a foaming component and, while extruding the rubber composition into a tubular body, continuously foaming and crosslinking the rubber composition of the tubular body by a continuous crosslinking apparatus including a microwave crosslinking device and a hot air crosslinking device. An image forming apparatus incorporates the toner supply roller (1).

Abstract: An electrically conductive rubber composition is provided, which comprises a rubber component including an SBR, an EPDM and an epichlorohydrin rubber, a crosslinking component and an azodicarbonamide foaming agent having a volume-based median diameter of 20 to 40 ?m. The azodicarbonamide foaming agent is blended in a proportion of 0.5 to 8 parts by mass based on 100 parts by mass of the overall rubber component. A transfer roller (1) is produced by extruding the electrically conductive rubber composition into an elongated tubular body, and continuously feeding out the tubular body in the elongated state without cutting the tubular body to continuously pass the tubular body through a microwave crosslinking device and a hot air crosslinking device to continuously foam and crosslink the tubular body.

Abstract: An electrically conductive rubber composition is provided, which comprises a rubber component including an SBR, an EPDM and an epichlorohydrin rubber, a crosslinking component and an azodicarbonamide foaming agent having an average particle diameter of 3 to 11 ?m. The azodicarbonamide foaming agent is blended in a proportion of 0.5 to 8 parts by mass based on 100 parts by mass of the overall rubber component. A transfer roller (1) is produced by extruding the electrically conductive rubber composition into an elongated tubular body, and continuously feeding out the tubular body in the elongated state without cutting the tubular body to continuously pass the tubular body through a microwave crosslinking device and a hot air crosslinking device to continuously foam and crosslink the tubular body.

Abstract: The present invention provides an electrically conductive rubber composition which can be efficiently and sufficiently foamed and crosslinked by means of a continuous crosslinking apparatus including a microwave crosslinking device and a hot air crosslinking device without generation of ammonia and carbon monoxide. The electrically conductive rubber composition comprises a rubber component, a crosslinking component for crosslinking the rubber component, and a foaming component including sodium hydrogen carbonate and citric acid.

Abstract: A rubber foam tube (5) is produced by extruding a rubber composition into a tubular body (4) and feeding the tubular body (4) in an elongated state without cutting to pass the tubular body (4) through a microwave crosslinking device (8) and then through a hot air crosslinking device (9) for continuously foaming and crosslinking the rubber composition. At this time, a ratio V2/V1 between a speed V2 at which the tubular body (4) passes through the hot air crosslinking device (9) and a speed V1 at which the tubular body (4) passes through the microwave crosslinking device (8) is not less than 1.0 and not greater than 1.6.