Issued Patents 1982
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4348508 | 3-Substituted-7-alkoxy-2,2'-Spirobi[2H-1-benzopyrans] | John E. Herweh, Alan B. Magnusson | 1982-09-07 |
| 4346186 | Process for fixing photo-induced colored derivatives of spiropyrans and compositions therefor | John E. Herweh, Alan B. Magnusson, Normal L. Miller | 1982-08-24 |
| 4342696 | 7-Dimethylamino-3-substituted-2,2'-spirobi[2H-1-benzopyrans] | John E. Herweh, Alan B. Magnusson | 1982-08-03 |