METHOD OF PREPARING BUTYL RUBBER Russian patent published in 2002 - IPC

FIELD: chemical industry. SUBSTANCE: described is method of preparing butyl rubber which is carried out by copolymerization of isobutylene with isoprene. Said method comprises preparation of isobutylene by hydration of isobutylene present in original isobutylene-containing fractions prepared by pyrolysis of hydrocarbon stock, catalytic cracking, dehydrogenation of isobutane, isomerization of normal structure butenes into trimethylcarbinol and dehydration of trimethylcrbinol into isobutelene followed by isolation thereof from trimethylcarbinol dehydration products by compression and rectification, and preparation of blend from isobutylene, isoprene and methylchlorylisobutylene fraction, copolymerization of isobutylene with isoprene in the presence of catalyst, deactivation of catalyst, degrassing of rubber, processing of unpolymerized monomers and methyl chloride diluent by compression, drying and rectification, and isolation and drying of rubber. Isobutylene rectification stillage residue isolated from trimethylcarbinol dehydration products is subjected to rectification in combination with original isobutylene-containing fraction is washed off to remove nitrogen-containing compounds and to hydrate isobutylene, and stillage residue containing butenes, trimethylcarbide, isobutylene hydration and trimethylcarbinol dehydration by-products, carbonyl compounds together with spent C₄, hydrocarbon fraction withdrawn out of isobutylene hydration process, are rectified, unsaturated C₄, hydrocarbons are distilled off, the remaining product is further processed by rectification. In this case, isolated distillate is rectified in combination with original isobutylene-containing fractions, and stillage residues, e. g. isobutylene dimers, trimethyl-carbinol and ethers are used for preparing motor fuels or for well-known purposes. EFFECT: more efficient method of preparing butyl rubber. 1 dwg _