Anodic phosphonic/phosphinic acid duplex coating on valve metal surface

Coated aluminum stock, the coating comprised of:

• (a) a layer of non-porous aluminum oxide bonded to a surface of said stock;
• and
• (b) a functionalized layer of an organic monomeric phosphorus-containing compound chemically bonded to a surface of said oxide layer.

The coated aluminum stock in accordance with claim "wherein said functionalized layer has a thickness of less than 200.ANG..

A coated aluminum sheet and foil stock suitable for food and beverage container ends, the coating on said stock comprised of a layer of a non-porous aluminum oxide thereon, said porous layer having chemically bonded to a surface thereof, a functionalized layer of an organic monomeric phosphorus-containing compound.

Coated aluminum stock, the coating comprised of:

• (a) a layer of non-porous aluminum oxide bonded to a surface of said stock, the oxide layer having a density of 2.8 to 3.2 gms/cc, a thickness in the range of 100 to 5000.ANG., being greater than 95 wt. % aluminum oxide, the oxide layer resulting from anodization in a monomeric phosphorus-containing acid selected from phosphonic and phosphinic acid produced at 12 to 16.ANG./V and at a weight gain of 0.03 to 0.2 mg/coulomb;
• and
• (b) a functionalized layer of an organic monomeric phosphorus-containing compound chemically bonded to a surface of said oxide layer, the oxide layer and the functionalized layer having a ratio of phosphorus to aluminum in the range of 0.01 to 0.5.