| abstract |
The disclosure relates to a process for applying a multilayer protective coating to a substrate having an electrically conductive surface, comprising: (a) a first method of forming a silicate layer upon said electrically conductive surface, said first method comprising contacting at least a portion of said surface with a first medium comprising at least one silicate and having a basic pH and wherein said first medium is substantially free of chromates, to form a silicate layer, and (b) a second method of electrolytically applying a synthetic resin layer upon the surface of said silicate layer, said second method comprising contacting at least a portion of said surface of said silicate layer with a second medium comprising a resinous ingredient, applying an electric current to said second medium wherein said surface is employed as an electrode, to form a synthetic resin layer. The multilayer protective coating exhibits excellent corrosion and adhesion properties and is environmentally acceptable. |