| 摘要 |
<p>A process for producing a thermoplastic elastomer comprising a block copolymer of the A-B-A' type, wherein A is a monovinyl aromatic hydrocarbon polymer block, B is a conjugated diolefin polymer block, and A' is either the same as A or a polymer block derived from a dialkenyl aromatic hydrocarbon or a dihalogenated hydrocarbon, which process comprises polymerizing a monovinyl aromatic hydrocarbon in a polymerization medium in the presence of an organomonolithium compound as a polymerization initiator, adding a conjugated diolefin to perform block copolymerization, and further adding a monovinyl aromatic hydrocarbon to perform polymerization or in the alternative, adding a dialkenyl aromatic hydrocarbon or a dihalogenated hydrocarbon to perform coupling, wherein the monomer components are used in such amounts that the weight ratio of (A + A') to B ranges from 10/90 to 65/35, and a chained aliphatic hydrocarbon solvent containing from 0.0001 to 0.1 wt% of a Lewis basic compound is used as the polymerization medium, is disclosed. According to the process of the invention, the desired thermoplastic elastomer having good physical properties is readily obtainable with high reproducibility.</p> |
