Electrochemically produced TiO2 layers for providing corrosion protection or wash primers

摘要

A layer of inorganic compound of a metal (A) is electrochemically-deposited onto the conductive surface from a solution of the metal (A); weight applied being 0.01-10 g/m2. The metal (A) is other than that forming the main component of the surface. The inorganic compound contains less than 20 wt% of phosphate ions. An Independent claim is included for a corresponding method of making an at least two-layer coating on an electrically-conductive surface. The second layer is added in a further stage, in which a coating of an organic polymer is applied. Preferred features: The deposited compound is an oxide. Deposition takes place at a potential relative to a standard hydrogen electrode of +/- 0.1V to +/- 300V; or a current density of +/- 0.1 - +/- 10000 mAcm-2. The inorganic compound is x-ray crystalline. In applying a second layer, a cathodically- or anodically- deposited electro-dip paint is applied. The process is a continuous sheet operation, the polymer layer being applied by dipping, spraying-on or using a coating roller. A powder paint is applied. Adhesive is applied. A corresponding metal component with double layer coating is also claimed.