To obtain the subject new initiator comprising a specific compound, capable of reducing the content of a monomer in the produced polymer particles, capable of adjusting the physical properties and mol.wt. of the produced polymer and capable of efficiently polymerizing the monomer.
This emulsion polymerization initiator comprises a compound of formula I (R1, R2 are each a lower alkyl; R is an alkylene in whose chain an O atom may be contained), e.g. dimethyl 2,2'-azobisisobutyrate of formula II. The monomer phase/aqueous phase distribution coefficient of the polymerization initiator has preferably e.g. 100-0.1, and the polymerization initiator is used in an amount of 0.01-0.5mol per 1000ml of the monomer. The monomer is preferably styrene, etc.
HIROSE SEIJI
YAMASHITA YOSHIHISA
