| abstract |
(57) 【Abstract】 PROBLEM TO BE SOLVED: To use in a pressure curing molding machine for a hydrocarbon rubber such as a pneumatic rubber tire, which has large slipperiness, small tackiness, long flex crack life, and small heat deformability. Provide an inflatable bladder. A bladder is a crosslinked elastomer containing isobutylene repeating units, and the bladder composition contains a finely particulate fluorinated ethylene polymer dispersed throughout the bladder. The bladder may also include graphite. The recommended isobutylene elastomer is a bromide of a copolymer of 80 to 99 weight percent isobutylene and 1 to 20 weight percent para-methylstyrene. This bladder has large slipperiness, low adhesion to the inner liner of the cured tire, cracks are less likely to occur during bending, and high temperature permanent strain is small. By such improvement of properties, it is possible to form a tire having less defects caused by worn or deformed hydrocarbon rubber. These features extend the useful life of the bladder and reduce the cost of curing the tire. |