Patent ID: 10160863

Abstract:
An object of the present invention is to find a primer coating composition for aluminum wheels, the composition having excellent stability and being capable of forming a coating film having excellent corrosion resistance, edge corrosion resistance, and filiform corrosion resistance. The invention provides (1) a primer coating composition for aluminum wheels comprising a copolymer resin (A), and 1 to 30 parts by mass of fumed silica (B) and 0.1 to 10 parts by mass of a magnesium-containing phosphoric acid-based compound (C), per 100 parts by mass of the total solids content of the copolymer resin (A). The invention also provides (2) the primer coating composition for aluminum wheels according to Item (1), further comprising 0.1 to 10 parts by mass of metal-ion exchanged silica (D), per 100 parts by mass of the total solids content of the copolymer resin (A).