METHOD FOR OBTAINING BUTADIENE-STYRENE COPOLYMERS Russian patent published in 2018 - IPC C07C29/70 C07C31/30 C08F236/10 

FIELD: technological processes.

SUBSTANCE: invention relates to the preparation of a modifying additive, which is a mixed alcoholate of alkali and alkaline earth metals. Method for preparing a modifying additive comprising the following steps is described: 1) carrying out the reaction of an alkali metal hydroxide with a mixture of alcohols in a hydrocarbon solvent medium, the equivalent ratio of the hydroxide of the alkali metal to the hydroxyl groups of the alcohols being 1.0:(1.2÷1.7); 2) reacting remaining unsubstituted hydroxyl groups with calcium at a temperature of 115–120 °C, with the equivalent ratio "hydroxyl group : calcium" being 1.0:(0.45÷0.55); 3) introducing into the reaction mixture of halogen alkyl, taken in the equivalent ratio "alcoholate group of alkali metal : haloalkyl", of 1.0:(0.1÷0.8), and carrying out the reaction at a temperature of 115–120 °C. Modifying additive prepared by the above method is also described. Method for the preparation of highly vinyl random copolymers of butadiene with styrene is described, comprising the steps of an anionic copolymerization of butadiene and styrene monomers in a hydrocarbon solvent medium carried out in the presence of an organolithium compound and the above modifying additive.

EFFECT: obtaining a highly effective modifying additive providing the preparation of random copolymers of butadiene with styrene with a high content of 1,2-units.

12 cl, 4 tbl, 9 ex