Butyl rubber has good chemical stability and thermal stability, and the most outstanding are air tightness and water tightness. Its air permeability is only 1/7 of that of natural rubber and 1/5 of that of styrene-butadiene rubber, while its steam permeability is 1/200 of that of natural rubber and 1/140 of that of styrene-butadiene rubber. Therefore, it is mainly used for manufacturing various rubber products such as inner tubes, steam pipes, water tyres, dam bottom and gaskets.

Since the industrial production of butyl rubber, the raw material route, production process and the structure of polymerization kettle have not changed much. Generally, methyl chloride is used as diluent and aluminum trichloride is used as catalyst. The monomer conversion can be adjusted by controlling the amount of these two. The polymerization of butyl rubber is carried out by positive ion reaction. The reaction temperature is low, the reaction speed is fast, the exothermic heat is concentrated, and the molecular weight of the polymer decreases sharply with the increase of temperature. Therefore, it is the main problem in production to rapidly discharge the polymerization heat to control the reaction at a constant low temperature.