METHOD OF PRODUCING HIGHLY REACTIVE, LOW MOLECULAR WEIGHT POLYISOBUTYLENE Russian patent published in 2013 - IPC C08F110/10 C08F10/10 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing low molecular weight polyisobutylene and can be used in the industry of synthetic rubber, and the obtained product can be used as a base for succinimide and thickening additives. The highly reactive, low molecular weight polyisobutylene is obtained by polymerising isobutylene or an isobutylene-containing hydrocarbon fraction in the presence of a Friedel-Crafts catalyst and a speed controller - isobutylene dimers or trimers or mixtures thereof in ratio dimer:trimer ranging from 1:1 to 10:1 by weight in amount of 1-15 wt % with respect to isobutylene. The speed controller is added before and after adding the catalyst. The catalyst used is a preformed complex (BF₃)x(ROH)x(ROR)x solvent, where R is an n-butyl, sec-butyl, tert-butyl, phenyl radical, R is a methyl, ethyl, isobutyl, n-butyl radical, R is an isobutyl, butyl radical and the solvent is toluene, hexane, with molar ratio (BF₃):(POH):(R'OR"):solvent equal to 1:(0.01-3):(0.001-0.1):(10-100). Polymerisation is carried out at temperature ranging from minus 15°C to plus 15°C and feeding the catalyst complex on BF₃ 0.02-0.4 wt % to isobutylene.

EFFECT: method enables to obtain polyisobutylene with high content of terminal double bonds in the α-position (at least 85 mol. %), with polydispersity index M_w/M_n of not more than 2,0 and with a stable interval of average molecular weight of 800-1500 units.

2 cl, 1 tbl, 9 ex