Process for production of fluorine-containing block copolymer

摘要

Provided is a process for the production of a fluorine-containing block copolymer, which suppresses the formation of a homopolymer as a by-product and which, regardless of whether the chain transfer constant of the iodine end is large or small, achieves nearly 100% conversion into a block copolymer. The process is characterized by reacting (A) a fluorine-containing polymer which has an iodine atom or a bromine atom at either or both terminals of the backbone chain and/or at a side-chain terminal with (M) a radical-polymerizable monomer in the presence of (C) a sulfur compound represented by general formula (2): (Y1)nH2-nS2O4 (wherein Y1 is a mono- or divalent metal ion or an ammonium ion; and n is an integer of 0 to 2).

主权项

1. A method for producing a fluorine-containing block copolymer, comprising
reacting a fluoropolymer (A) having an iodine atom at either or both ends of its main chain and/or an end of its side chain with a radical polymerizable monomer (M) in the presence of a sulfur compound (C) represented by formula (2):
(Y1)nHmS2O4  (2) wherein Y1 is a monovalent metal ion or an ammonium ion, n is 1 and m is 1; Y1 is a monovalent metal ion or an ammonium ion, n is 2 and m is 0; or Y1 is a divalent metal ion, n is 1 and m is 0, said fluoropolymer (A) further having a terminal structure represented by —CH2I and being a vinylidene fluoride fluororesin represented by formula (5):
-(A3)-(A4)-(B2)-  (5) wherein the structural unit A3 is a structural unit derived from a vinylidene fluoride (a3); the structural unit A4 is a structural unit derived from a fluoroethylenic monomer (a4); and the structural unit B2 is a repeating unit derived from a monomer (b2) copolymerizable with the monomer (a3) and the mononer (a4).