PROCESS FOR RECOVERY OF BUTADIENE-(α-METHYL)STYRENE RUBBER Russian patent published in 1996 - IPC

FIELD: production of butadiene (a-methyl) styrene rubber. SUBSTANCE: process for recovery of butadiene (a-methyl) styrene rubber is carried out by coagulation of rubber latex in acid medium in the presence of additive and uses recycle of serum. The additive is poly-N,N-dimethyl-N,N-diallyl ammonium chloride. Coagulation is carried out in two or thres stages. When coagulation is carried out in two stages at first stage, rubber latex is mixed with acidified serum- containing additive with pH of the total mixture of 5-6; at second stage the resulting mixture is mixed with aqueous acid solution with pH of 3.5-4.5. When coagulation is carried out in three stages, prior to said two stages, the starting latex is mixed with aqueous solution of polu-N,N-dimethyl-N,N-diallyl ammonium chlorido additive being used in amount of 0.1-1.5 kg/t of rubber. Irrespective of the number of stages, the minimum amount of poly-N,N-dimethyl-N,N-diallyl ammonium chloride additive is 1.5 kg/t of rubber. EFFECT: more refficient recovery process. 1 dwg, 3 tbl