FIELD: chemistry.
SUBSTANCE: present invention relates to a method for copolymerisation of conjugated dienes and vinyl aromatic monomers, copolymers obtained using said method, as well as to rubber mixtures based on the obtained copolymers. Method of producing modified copolymers is carried out by copolymerisation of conjugated dienes and vinyl aromatic monomers in a hydrocarbon solvent medium in the presence of an electron-donor additive, an organolithium compound as an initiator of at least one tin-containing modifier introduced after achieving at least 95 % conversion of monomers, and stabilizing the obtained polymerisate using an antioxidant system consisting of phenol (1) and phosphite (2) antioxidants taken in ratios (1):(2) = 1:(1–5) wt. parts, provided that the pH of the aqueous extract of the polymerisate ranges from 6 to 8. Copolymer produced according to the invention is characterized by content of 1,2-links from 10 to 70 wt. %, value of Mooney viscosity from 50 to 85 conv. Mooney units, the ratio of the molecular weight Mz/Mn of from 3 to 4 units.
EFFECT: invention improves processability of the polymer during its production and processing, improves stability of the polymer during storage and processing thereof, as well as to improved vulcanisation and hysteresis characteristics of rubber mixtures obtained based on the disclosed polymer, by inhibiting decomposition processes and accelerating the vulcanisation process.
14 cl, 3 tbl, 19 ex
