| abstract |
The primer composition of the invention is particularly useful as an undercoating composition for a protective overcoating formed with a silicone-based coating composition containing a colloidal silica powder in respect of the excellent adhesion, heat resistance, resistance against hot water and weatherability of the overcoating layer. The primer composition essentially comprises two components including (a) 100 parts by weight of a copolymer of a monomer mixture composed of (a-1) from 2 to 50% by weight of an ethylenically unsaturated monomeric compound having, in a molecule, an alkoxysilyl group and (a-2) from 98 to 50% by weight of an ethylenically unsaturated monomeric compound free from alkoxysilyl groups and copolymerizable with the monomeric compound (a-1); and (b) from 5 to 300 parts by weight of an amidated product obtained by the reaction of a halide, anhydride or isopropenyl ester of a carboxylic acid and a product obtained by the reaction of an amino group-containing alkoxysilane compound, an epoxy group-containing alkoxysilane compound and a silylating agent. |