Patent ID: 9733564
Date: 2017-08-15
CPC Classifications: C08F,G01N,G03F

Claim:
1. A method for producing a polymer by copolymerization of at least two monomers α 1 to α n having different copolymerization reactivities to obtain a polymer (P) comprising at least two monomer units α′ 1 to α′ n in a target composition having a content ratio of the monomer units α′ 1 to α′ n of (P) according to α′ 1 :α′ 2 : . . . :α′ n ; the method comprising: first feeding dropwise to a polymerization reactor at least one solution Sa comprising the at least two monomers α adding to the reactor dropwise a polymerization initiator either after the addition of the at least one solution Sa or simultaneous with the addition of Sa, feeding to the reactor at least one solution Tb comprising the at least two monomers α feeding at least one solution Uc comprising the at least two monomers α wherein n is an integer of at least 2, when a standard time is defined as a time elapsed from the start of the addition of the polymerization initiator to completion of the addition of Tb, the polymerization initiator is added at such rate that 30 to 90% of the total feed of the polymerization initiator is added during the initial 5 to 20% of the standard time, and a total amount of the monomers in the at least one solution Uc is from 0.1 to 10 mass % of a total feed amount of the monomers.