Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7311787 | Method for the darkening of a surface layer of a piece of material containing zinc | Thomas Kruse | 2007-12-25 |
| 6758956 | Method for darkening a superficial layer which contains zinc and which is of a material piece | Thomas Kruse | 2004-07-06 |