| (19) |
 |
|
(11) |
EP 1 221 497 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
03.12.2003 Bulletin 2003/49 |
| (43) |
Date of publication A2: |
|
10.07.2002 Bulletin 2002/28 |
| (22) |
Date of filing: 18.06.1999 |
|
|
| (84) |
Designated Contracting States: |
|
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE |
| (30) |
Priority: |
19.06.1998 US 90017 P
18.06.1999 US 335676
|
| (62) |
Application number of the earlier application in accordance with Art. 76 EPC: |
|
99930410.8 / 1088119 |
| (71) |
Applicant: Alcoa Inc. |
|
Pittsburgh, PA 15212-5858 (US) |
|
| (72) |
Inventors: |
|
- Nitowski, Gary A.
Alcoa Center, PA 15069-0001 (US)
- Colbert, Raymond J.
Alcoa Center, PA 15069-0001 (US)
- Wefers, Karl
Apollo, PA 15613 (US)
- Roup, Daniel D.
Riverdale, IA 52722 (US)
- Wieserman, Larry F.
Alcoa Center, PA 15069-0001 (US)
|
| (74) |
Representative: Ebner von Eschenbach, Jennifer et al |
|
Ladas & Parry, Dachauerstrasse 37
80335 München
80335 München (DE) |
|
| |
|
| (54) |
Method for inhibiting stains on aluminum product surfaces |
(57) A method for inhibiting the formation of stains, expecially water stains, on the
exterior surfaces of aluminum alloy products. The method entails contacting the exterior
surfaces of these products, particularly sheet or plate products, extrusions and/or
forgings made from 5000 or 6000 Series aluminum alloys, with an organophosphonic or
organophosphinic acid-derived material. Preferably, liquid forms of this material
are added to an alcohol or water-based carrier solution, then sprayed, dipped, painted
or rolled onto the surfaces of flat sheet or plate products to enhance their brightness.
Other more complex shapes may be dipped into material baths.