Patent ID: 6955728

Claim:
A method of treating a metal surface, comprising the steps of: (a) providing a metal substrate; and (b) applying an aqueous solution to said metal substrate, said solution comprising: (i) at least one acyloxy silane, wherein said acyloxy silane comprises at least one acyloxy group, and wherein said acyloxy silane has been at least partially hydrolysed and is either (A) a single tetrasubstituted silicon atom wherein the substituents are individually selected from the group consisting of alkyl, alkenyl, alkynyl, aryl, alkaryl, aralkyl, vinyl, amino, ureido, glycidoxy, epoxy, hydroxy, alkoxy, aryloxy, acyloxy, and any of the group alkyl, alkenyl, alkynyl, aryl, alkaryl and aralkyl substituted by a group selected from the group consisting of vinyl, amine, ureido, glycidoxy, epoxy, hydroxy and alkoxy, with the proviso that at least one of the substituents on the silicon atom is an acyloxy group; or (B) a multisilyl acyloxy silane; and (ii) at least one basic silane compound which is selected from the group consisting of (A) compounds having the general structure wherein R 2 is chosen from the group consisting of hydrogen and C 1 –C 24 alkyl, and each R 2 may be the same or different; X 1 is selected from the group consisting of a bond, substituted and unsubstituted aliphatic groups and substituted and unsubstituted aromatic groups; and R 3 is a group individually selected from the group consisting of hydrogen, C 1 –C 6 alkyl, C 2 –C 6 alkenyl, C 1 –C 6 alkyl substituted with at least one amino group, C 2 –C 6 alkenyl substituted with at least one amino group, arylene and alkylarylene; and (B) a bis-silyl aminosilane(s) having the structure wherein R 4 is individually selected from the group consisting of: hydrogen and C 1 –C 24 alkyl; R 5 is individually selected from the group consisting of: substituted aliphatic groups, unsubstituted aliphatic groups, substituted aromatic groups, and unsubstituted aromatic groups; and —X 2 is either: wherein each R 6 is individually selected from the group consisting of: hydrogen, substituted and unsubstituted aliphatic groups, and substituted and unsubstituted aromatic groups; and R 7 is selected from the group consisting of: substituted and unsubstituted aliphatic groups, and substituted and unsubstituted aromatic groups wherein the acyloxy silane and the basic silane compound are present in concentrations to provide a solution pH of between 3 and 10 and wherein the solution is substantially free of acid other than acid produced upon hydrolysis of the acyloxy silane.