PURPOSE: To obtain an aqueous dispersion type composition having stability free from change in viscosity for a long period of time, providing a coating film having excellent weather resistance by polymerizing a specific silyl group- containing vinyl monomer with a copolymerizable monomer in an aqueous medium in the presence of a specific silyl group-containing water-soluble resin.
CONSTITUTION: (B) A silyl group-containing vinyl monomer of formula II (R2 1-10C alkyl, aryl, etc.; X is halogen, hydroxy, etc.; (b) is 02) (e.g. γ- methacryloyloxypropyltrimethoxysilane) is copolymerized with (C) a monomer copolymerizable with the component B preferably in the presence of (A) a sily group-containing water-soluble resin of formula I (R1 is as shown for R2; n is 2-15; a is b) preferably at 40-80°C to give the objective composition. The component A is preferably obtained by copolymerizing the component B with a water-soluble vinyl monomer such as acrylic acid and a monomer copolymerizable with the component and the monomer, such as (meth)acrylate and optionally making the obtained polymer water-soluble.
MASUDA TOSHIYUKI
HATANO TAKANORI
