Patent ID: 6479109
Filing Date: 2002-11-12
Classification: C08F,C08G,C08L,C09D,Y10S

Abstract:
A method of electrocoating a conductive substrate serving as a cathode in an electrical circuit comprising said cathode and an anode, said cathode and anode being immersed in an aqueous electrocoating composition, comprising passing electric current between said cathode and anode to cause deposition of the electrocoating composition on the substrate as a substantially continuous film, the aqueous electrocoating composition comprising:(a) an ungelled active hydrogen group-containing block copolymer containing onium salt groups prepared by atom transfer radical polymerization in the presence of an initiator having at least one radically transferable group, wherein said block copolymer contains at least one of the following polymer chain structures: â€”[â€”(G)jâ€”(M)kâ€”(A)lâ€”]xâ€”; â€”[â€”(G)jâ€”(A)lâ€”(M)kâ€”]xâ€”; â€”[â€”(A)lâ€”(G)jâ€”(M)kâ€”]xâ€”; â€”[â€”(M)kâ€”(A)lâ€”(G)jâ€”]xâ€”; â€”[â€”(M)kâ€”(G)jâ€”(A)lâ€”]xâ€”; â€”[â€”(A)lâ€”(M)kâ€”(G)jâ€”]xâ€”; â€”[â€”[â€”(M)kâ€”(A)lâ€”]qâ€”(G)jâ€”]xâ€”; â€”[â€”[â€”(M)kâ€”(G)jâ€”]qâ€”(A)lâ€”]xâ€”; â€”[â€”[â€”(A)lâ€”(M)kâ€”]qâ€”(G)jâ€”]xâ€”; orâ€”[â€”[â€”(G)jâ€”(M)kâ€”]qâ€”(A)lâ€”]xâ€”; where j, k, and l represent block lengths of the monomers, and q and x represent segment lengths, each are independently selected for each structure such that said polymer has a number average molecular weight of at least 1000; G is a residue of at least one ethylenically unsaturated radically polymerizable monomer, said residue containing onium salt groups; A is a residue of at least one ethylenically unsaturated radically polymerizable monomer, said residue being free of onium salt groups and containing active hydrogen groups; and M is a residue of at least one ethylenically unsaturated radically polymerizable monomer and is different from G and A; and (b) a curing agent having at least two functional groups which are reactive with the active hydrogen groups of (a).