PROCESS FOR PREPARING BUTYL RUBBER Russian patent published in 1997 - IPC

FIELD: petrochemical industry. SUBSTANCE: claimed process for preparing butyl rubber comprises polymerizing isobutylene with isoprene in hydrocarbon solvent in the presence of diluent, chloroorganic compound, e.g. ethyl chloride, and catalyst, e.g. halogen aluminium alkyl comprising also stabilizing and rubber solution, recovery and drying thereof. Monomer copolymerization is first carried out in acid medium then in alkaline medium, the copolymerization process, being carried out both in one or consecutively connected reactors. Alkaline medium or lower acidity of the monomer copolymerization is provided by addition of ethanol amines. Lower acidity of the process can also be obtained by addition of hydroxides of alkaline metals such as potassium or sodium. Ethanolamines are added in amounts or 25-75 wt% from the amount of catalyst fed for the monomer copolymerization. The latter is carried out at temperatures by 10-40 C higher than the temperature of the process carried out in acid medium. EFFECT: more efficient preparation process. 7 cl, 2 dwg, 5 tbl