Plasma polymerized interfacial coatings for improved adhesion of sputtered bright metal on plastic

Claim 1

A method of improving adhesion between layers of a thermoplastic urethane article sputtered with a bright metal coating comprised of chromium metal and having a clear protective urethane overcoating comprising: providing a clean sputtering surface on a said thermoplastic urethane article; exposing said surface to a radio frequency induced plasma of acetonitrile monomer such that a coherent thin coating layer of polymerized acetonitrile is formed thereon; sputtering said article with a bright metal coating layer containing chromium metal; exposing said metal coating layer to a second radio frequency induced plasma of acetonitrile to form a second coherent thin coating layer of polymerized acetonitrile thereon; and covering said second polymerized acetonitrile layer with a clear compatible, protective layer comprised of polymeric urethane.

Claim 2

A method of improving adhesion between layers of a thermoplastic urethane article sputtered with a bright metal coating comprised of chromium metal and having a clear protective urethane overcoating comprising: providing a clean sputtering surface on a said thermoplastic urethane article; exposing said surface to a radio frequency induced plasma of acetonitrile monomer such that a coherent thin coating layer of polymerized acetonitrile is formed thereon; sputtering said article with a bright metal coating layer containing chromium metal; exposing said metal coating layer to a second radio frequency induced plasma of acetonitrile to form a second coherent thin coating layer of polymerized acetonitrile thereon; and covering said second polymerized acetonitrile layer with a clear compatible, protective layer comprised of polymeric urethane.

Claim 3

A method of improving the adhesion of sputtered chromium or chromium metal alloy to a flexible, thermoplastic urethane substrate comprising the steps of exposing said urethane substrate to a radio frequency induced plasma of acetonitrile monomer in an inert gas atmosphere thereby polymerizing said monomer on the substrate surface and forming a receptive underlayer for said metal; sputtering the acetonitrile plasma exposed substrate with a coating of said chromium or chromium alloy; and thereafter exposing said chromium sputtered substrate to a second radio frequency induced plasma of acetonitrile monomer to form a polymerized protective overlayer therefor, whereby said method the plasma polymerized acetonitrile underlayer and overlayer provide improved adhesion of the sputtered chromium to the urethane substrate as measured by a tape adhesion test.

Claim 4

A method of improving the adhesion of sputtered chromium or chromium metal alloy to a flexible, thermoplastic urethane substrate comprising the steps of exposing said urethane substrate to a radio frequency induced plasma of acetonitrile monomer in an inert gas atmosphere thereby polymerizing said monomer on the substrate surface and forming a receptive underlayer for said metal; sputtering the acetonitrile plasma exposed substrate with a coating of said chromium or chromium alloy; and thereafter exposing said chromium sputtered substrate to a second radio frequency induced plasma of acetonitrile monomer to form a polymerized protective overlayer therefor, whereby said method the plasma polymerized acetonitrile underlayer and overlayer provide improved adhesion of the sputtered chromium to the urethane substrate as measured by a tape adhesion test.