Self-releasing curing bladders

摘要

The invention relates to expandable butyl rubber bladders for use in curing presses for hydrocarbon rubbers such as pneumatic tires. The bladders are a crosslinked butyl rubber composition comprising isobutylene repeat units and the bladder composition contains ultra high molecular weight polyethylene, alone or in combination with graphite and/or fluorinated ethylene polymers, dispersed within the bladder composition. The bladder composition may also contain castor oil, corn oil and/or soya-bean oil. The invention also relates to a method of curing tires by utilizing such butyl rubber bladder.