Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4874502 | Method of purifying coal tars for use in the production of carbon products | Masatoshi Tsuchitani | 1989-10-17 |
| 4820401 | Process for the preparation of mesophase pitches | Masatoshi Tsuchitani, Ryoichi Nakajima | 1989-04-11 |