Method of coating metal using low temperature plasma and electrodeposition
AssigneeE. I. Du Pont de Nemours and Company
InventorsJoseph A. Antonelli, Tyau-Jeen Lin, Duck J. Yang, Hirotsugu Yasuda
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Abstract
This invention relates to the use of low temperature plasma technology for significantly improved corrosion protection of metals. The plasma process involves pretreatment of the surface of the metal with a gas plasma to remove oxygen, followed by plasma deposition of a thin polymeric film on the treated surface, followed by cathodic electrocoat application of a primer.
Claims9
A method of coating a metal substrate to provide corrosion protection, which method comprises the following steps:
- (a) pretreating the metal substrate with a gas plasma to reduce or remove surface oxides from the metal substrate;
- (b) forming an oxygen-free film on the pretreated metal substrate by means of plasma deposition, comprising polymerizing a non-oxygen containing organic compound, wherein the plasma deposition employs DC power and is carried out in a vacuum chamber enclosing a cathode and anode, and wherein the metal substrate is the cathode;
- and
- (c) applying a primer by cathodic electrocoating the primer over said oxygen-free film.
A method of coating a non-galvanized metal substrate to provide corrosion protection, which method comprises the following steps:
- (a) pretreating the non-galvanized metal substrate with a gas plasma to substantially remove oxygen and oxides from the surface of the metal substrate;
- (b) forming an organic polymeric film on the pretreated non-galvanized metal substrate by means of plasma deposition, wherein the plasma deposition employs DC power and is carried out in a vacuum chamber enclosing a cathode and anode, and wherein the metal substrate is the cathode;
- and
- (c) applying a primer by cathodic electrocoating the primer over said organic polymeric film.
Dependencies are inferred from the claim text.