METHOD FOR PRODUCING LOW MOLECULAR WEIGHT HIGHLY REACTIVE POLYISOBUTYLENE Russian patent published in 2023 - IPC C08F10/10 C08F110/10 C08F2/00 C08F4/12 C08F4/14 

FIELD: polyisobutylene production.

SUBSTANCE: present invention relates to a process for producing low molecular weight highly reactive polyisobutylene by carrying out the cationic polymerization of isobutylene or an isobutylene-containing hydrocarbon fraction in the presence of a Lewis acid/base catalyst complex. This method includes dosing at a rate of 2-6 vol.% per minute into a cooled apparatus with a stirrer at a temperature of -20-0°C and mixing simultaneously supplied from two containers a solution of butylene-isobutylene or isobutane-isobutylene fraction in n-hexane or methylene chloride at a concentration of isobutylene in solution within 10–25 wt.%, and a solution of the catalytic complex in a mixed solvent containing n-hexane with methylene chloride in a volume ratio of 0-1: 1-0. Next, the resulting mixture of solutions is kept for 15-50 minutes, followed by deactivation of the catalytic complex by reacting the resulting reaction mixture for 30-120 minutes with aluminum oxide. The isobutylene residues and other C₄ hydrocarbons included in the isobutylene-containing fraction, the lower isobutylene oligomers, the Lewis base used, and the solvents are then distilled off under vacuum. The catalytic complex consists of a Lewis acid, which is boron trifluoride or aluminum chloride, and a Lewis base, which acts as an electron donor component, which is a С₁-С₈ aliphatic alcohol or a С₂-С₈ ether, with a ratio of Lewis acid to Lewis base in the range of 0.8- 1:1 by moles. The catalytic complex is taken in an amount of 0.2 - 1 mol.% relative to isobutylene.

EFFECT: simplification of the production process of low molecular weight highly reactive polyisobutylene and increase its productivity while ensuring the quality of the resulting product.

1 cl, 3 dwg, 2 tbl, 8 ex