PROCESS FOR PREPARING MODIFIED BUTADIENE RUBBER Russian patent published in 1999 - IPC

FIELD: manufacture of asphalt-bitumen coatings, sealants as additive to rubber mixes. SUBSTANCE: rubber is prepared from branched polybutadiene containing 30-70 % vinyl units. In one apparatus dissolution and destruction are carried out at 140-200 C followed by addition of oil to attain rubber content of 15-30 wt % in oil and by decreasing temperature to 70-120 C, and in second apparatus dissolution is carried out in oil at 70-120 C to attain polymer concentration of 15-25 wt % followed by mixing at weight ratio of first solution to second solution from 0.1-1 to 1:1 and to attain polybutadiene content of 15-30 wt %. Polybutadiene has preferably 1 or 2 units in oils and higher concentration, but lower dynamic viscosity and retained properties of the solution. EFFECT: more efficient preparation process. 5 ex, 1 tbl