METHOD FOR PRODUCING POLYMER

PROBLEM TO BE SOLVED: To provide a method for efficiently producing a polymer having a desired molecular weight in high reproducibility by starting the polymerization after confirming a polymerization starting point at which impurities such as water and polymerization inhibitors in polymerization solvents, monomers, etc., are made to be harmless to practically enable the polymerization. SOLUTION: The method for the production of a polymer such as a styrene- butadiene copolymer comprises (A) the 1st step to continuously or intermittently add a polymerization catalyst or a polymerization initiator in the presence of the monomer until the temperature rising rate in a polymerizer reaches 0.02-0.3°C/min and (B) the 2nd step to perform the polymerization reaction after the completion of the 1st step by further adding the polymerization catalyst or the initiator contributing to the polymerization reaction. COPYRIGHT: (C)2003,JPO