| abstract |
PURPOSE: To obtain a copolymer desirable for a coating composition which is inexpensive and excellent in mold release, weathering properties, water repellency, stainproof properties, etc., by polymerizing a radical-polymerizable vinyl monomer in the presence of a radical initiator by using a specified dimethylpolysiloxane macromonomer as a chain transfer agent. n CONSTITUTION: A block copolymer obtained by polymerizing at least one radical-polymerizable vinyl monomer by using a dimethylpolysiloxane macromonomer having one mercaptoalkyl on the average and 1-3 alkoxysilyls in the molecule as a chain transfer agent. The macromonomer is represented by, for example, an average compositional formula I (wherein R 1 is a 1-10C bivalent hydrocarbon group which bonds the mercapto to the silicon atom; R 2 is a 1-4C monovalent hydrocarbon group; n is 3-100; and m is 1, 2 or 3). Examples of the radical-polymerizable monomers used include a (meth)acrylate, a styrene, a vinyl ester and acrylonitrile. n COPYRIGHT: (C)1991,JPO&Japio |