Chlorobutyl (CIIR) is a copolymer of chlorinated isobutylene and small amounts of isoprene which provides unsaturated sites for vulcanization. This elastomer has many of the attributes of butyl rubber, including low gas and moisture permeability, good vibration damping, low glass transition temperature, excellent resistance to ageing and weathering. Compared to butyl rubber, the chlorinated sites are more reactive, providing faster cure with lower amount of curatives and better adhesion to unsaturated rubbers and metals.
Chlorobutyl rubber is made in a continuous process by combining elemental chlorine to a butyl rubber hexane solution. One chlorine atom is injected at the position of each enchained isoprene unit in the rubber when the amount of chlorine is controlled
1. Automotives : tire inner liners such as tire inner tubes, tire sidewalls, automotive engine mounts
2. Industrial : conveyor belt covers