Butyl rubber is a kind of synthetic rubber, which is synthesized from isobutylene and a small amount of isoprene. Finished products are not easy to leak and are generally used to make tyres. Butyl rubber is a copolymer of isobutylene and isoprene. Butyl rubber is a kind of synthetic rubber, which is synthesized from isobutylene and a small amount of isoprene. It is generally used to make tyres. In the field of building waterproofing, butyl rubber has been widely used to replace asphalt in the name of environmental protection.