METHOD OF PREPARING CHLOROBUTYL RUBBER Russian patent published in 2000 - IPC

FIELD: chemical engineering, more particularly chemical modification of natural rubbers. SUBSTANCE: described is method of preparing chlorobutyl rubber by treatment of butyl rubber solution in organic solvent with chlorine-containing agent at temperatures from minus 10 to plus 70 C in two steps: two thirds of agent based on total amount is first added. The resulting chlorobutyl rubber is maintained for 20-120 minutes and the remaining portion is thereafter added and maintained for 10-60 minutes. 1-10 wt % of alkali or sulfite is added, washed with water and, the desired product is precipitated by aqueous degassing method. Method makes it possible to avoid using corrosion active chlorine and to improve physico-mechanical properties of vulcanizates. EFFECT: more efficient preparation method. 6 cl, 4 ex, 1 tbl