METHOD FOR IMPROVING COLD FLOW RESISTANCE OF POLYMER

摘要

PROBLEM TO BE SOLVED: To provide a method for improving cold flow resistance of a polymer.SOLUTION: A method for producing a polymer composition having improved cold flow resistance includes the steps of: preparing polymer cement comprising a polymer and a solvent; introducing an acetal or ketal of an alditol into the polymer cement; and separating at least a part of the polymer and the acetal or ketal of an alditol from the solvent to obtain a polymer composition comprising the polymer and the acetal or ketal of an alditol. The polymer comprises a polydiene or a polydiene copolymer. The polydiene is a polydiene having a cis-1,4-bond content of more than 90%. The polymer cement contains 10 mass% or more and 40 mass% or less of the polymer.