Water-dispersible core-shell resin which exhibits excellent sagging resistance in coatings

A water-dispersible resin composition prepared by a process comprising:

• (I) reacting a silane monomer (A) which is at least one monomer selected from the group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, acryloxyethyltrimethoxysilane, methacryloxyethyltrimethoxysilane, acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, acryloxypropyltriethoxysilane, methacryloxypropyltriethoxysilane and vinyltris (.beta.-methoxyethoxy) silane with a vinyl monomer (B) in an aqueous medium to obtain a three-dimensionally crosslinked particular polymer, (II) reacting the obtained particular polymer with the silane monomer (A) or a mixture of the silane monomer (A) and an allyl acrylate or allyl methacrylate (C), and (III) copolymerizing the resulting reaction product with a vinyl monomer component comprising a carboxyl-containing vinyl monomer (D), followed by neutralizing the carboxyl group whereby a particular polymer having a core/shell structure is obtained, wherein the monomers are used in steps (I) and (III) in the following proportions, based on the combined weight of all the monomers used in steps (I) and (III);
• about 60 to about 90% by weight in step (I);
• and about 40 to about 10% by weight in step (III).