| 摘要 |
PROBLEM TO BE SOLVED: To efficiently obtain the subject polymer having a narrow molecular weight distribution, by polymerizing a styrene-based compound up to a specific conversion ratio in the presence of a radical scavenger and specific, multi- functional peroxide. SOLUTION: This polymer is obtained by polymerizing (A) a styrene-based compound (e.g. styrene) up to a polymerization conversion ratio of 40 to 80% in the presence of (B) a radical scavenger (e.g. 2,2,6,6-tetramethyl-1- piperidinyloxy) and (C) a multi-functional peroxide shown by formula I [R1 and R2 are each shown by formulae II to IV (R1 to R4 are each H, a 1-5C alkyl, cyclohexyl or phenyl; L, (m) and (n) are each 0 to 20; and (k) is 2 to 30)] under the conditions of the concentration C of the component B(wt.ppm) relative to that of the component A being 100<=C<=1,000, concentration I(wt.ppm) of active oxygen in the component C relative to that in the component A being 10<=I<=1,000, and temperature of 100 to 140 deg.C. This polymer has a weight- average molecular weight Mw of 100,000 to 500,000, number-average molecular weight Mn of 50,000 to 400,000 and molecular weight distribution Mw /Mn of 1.5 to 2.0. |
