Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4874502 | Method of purifying coal tars for use in the production of carbon products | Sakae Naito | 1989-10-17 |
| 4820401 | Process for the preparation of mesophase pitches | Sakae Naito, Ryoichi Nakajima | 1989-04-11 |
| 4818449 | Process to prevent crack formation in the production of carbon fibers | Yasuhiro Yamada, Takeshi Imamura, Hidemasa Honda, Ryoichi Nakajima | 1989-04-04 |