| abstract |
(57) [Summary]nThe present invention relates to a non-abrasive, corrosion resistant hydrophilic coating applied to the surface of an aluminum sheet such as fin stock, which coating comprises nitrilotrismethylenetriphosphonic acid, phosphorus, in an aqueous vehicle. An acid and a borate selected from the group of zinc borate and sodium borate, but essentially free of silica, alumina and their precursors, the coating material being applied to the aluminum surface. And to obtain the coating by heating the surface to form the coating, the coating material also containing up to about 1% by weight of polyacrylic acid and a surfactant as an application aid. |