Silane based chromate replacements for corrosion control, paint adhesion, and rubber bonding

An overview is given of the use of silanes for corrosion control of metals and bonding of silane treated metals to paint systems and rubber compounds. Examples are git en of corrosion protection of cold rolled steel, galvanis ed steel, aluminium, and magnesium, both painted and unpainted. Emphasis in this work has been on the use of bis-silanes rather than the conventional mono-silanes. It is shown that mixtures of a bis-amino and a bis-polysulphu r silane work with a wide range of metals and paint systems,. A model is de scribed which is largely based on eletrochemical impedance spectroscopy (EI S) measurements. (C) 2000 IoM Communications Ltd.