Sumitomo Rubber Industries Limited

Yusuke Tanio

Naoyuki Satoyoshi

Keisuke Osaka

Shunichi Yabushita

Takuya Yamaguchi

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.

Rubber composition, rubber roller, and image forming apparatus

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. The transfer roller () is produced by extruding the electrically conductive rubber composition into a tubular body and performing an in-can vulcanization process on the tubular body. The image forming apparatus incorporates the transfer roller.

Electrically conductive rubber composition, transfer roller, production method for the transfer roller, and image forming apparatus

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 () includes a roller body () formed from the electrically conductive rubber composition.

Electrically conductive rubber composition, transfer roller, and image forming apparatus

A toner supply roller () 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 ().

Toner supply roller and image forming apparatus

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

Method of producing an electrically conductive roller from a rubber foam tube

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.

Growing community of inventors

Kobe, Japan

Yusuke Tanio