Method of making a shaped reflective aluminum strip, doubly-protected with oxide and fluoropolymer coatings
US5290424A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 1992 |
| Grant date | Mar 1, 1994 |
| Priority date | — |
| Expiry date | Jan 31, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D11/18
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A shaped strip of highly reflective aluminum protected by an anodic oxide coating and a light-permeable fluoropolymer coating which is non-adhesively interstitially mechanically bonded to the microscopic irregularities of the anodic oxide surface. There is no adhesive used to obtain chain entanglement. The highly reflective strip may be substituted for polished stainless steel and/or bi-metal and used under comparably aggressive conditions for a prolonged period without deleteriously affecting the initial D/I (distinctness of reflected image) of the shaped strip. The strip of arbitrary length is shaped in rolling dies so that at least a portion of the strip has a radius of less than 10 mm without damaging or separating the fluoropolymer coating. The specific steps of the claimed process require starting with a clean strip which is brightened to a nearmirror-like finish, then treated to carry a thin porous aluminum oxide coating in a phosphoric acid bath under direct current (DC). After rinsing and drying, the reflective surface is coated with the fluoropolymer while maintaining at least 80% D/I. The strip, now dual-coated, is then formed to a desired profile. The dual-coated strip,…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.