| 摘要 |
PURPOSE:To produce the titled copolymer excellent in rolling friction resistance, by polymerizing a vinyl aromatic compound with a conjugated diene compound under specified conditions. CONSTITUTION:To 100pts.wt. monomer mixture comprising 5-35pts.wt. vinyl aromatic compound and 95-65pts.wt. conjugated compound, 200-1,000pts.wt. hydrocarbon solvent, 0.01-0.2pt.wt. organolithium compound as an initiator and 0.01-3,000mol, per equivalent of Li atoms, of an ether and/or a tert. amine (e.g., ethylene glycol dimethyl ether). The polymerization of the mixture is started at -10-50 deg.C and continued at an elevated temperature <=150 deg.C. After the polymer conversion reaches 90-99%, 1-5pts.wt. conjugated diene compound is added continuously or intermittently and the polymerization is continued. This polymerization is stopped by the addition of a polyfunctional coupling agent (e.g., SnCl4) to obtain a conjugated diene copolymer having a total content of 1,2-bonds and 3,4-bonds of 20-70%. |
