The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 11, 1994
Filed:
May. 22, 1992
Gary A Nitowski, Natrona, PA (US);
Larry F Wieserman, Apollo, PA (US);
Karl Wefers, Apollo, PA (US);
Aluminum Company of America, Pittsburgh, PA (US);
Abstract
A twice-anodized aluminum substrate is anodized sequentially in first and second aqueous electrolytes. In the first, the substrate is conventionally anodized to produce (i) a porous anodic oxide layer having open pores and a passivation layer thereunder. The substrate, now singly-coated, is then anodized in the second electrolyte of an aqueous solution of an organophosphorus compound which generates a residue which is chemisorbed and covalently bonded to the substrate to form (ii) a monomolecular essentially continuous monolayer on the outer surface of (i), and at the same time, the second anodizing step produces (iii) a barrier layer of non-porous aluminum oxide under (i). The thickness of this barrier layer can be increased as a function of the voltage used while maintaining the thickness of (i) substantially constant, and (ii) protects (i) from dissolution. Depending upon the choice of the organophosphorus compound, a hydrophobic, or chemically resistant surface may be produced; or, a surface which provides a leaving group to be reacted with an appropriate organic coating to be applied after the triplex layer is formed.