Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5198584 | P-phenylenediamine substituted by a quaternary ammonium group and an electron withdrawing group | Y. G. Pan, D.C. Chang | 1993-03-30 |
| 5139532 | P-phenylenediamine substituted by a quaternary ammonium group and an electron withdrawing group | Y. G. Pan, David Chang | 1992-08-18 |