Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4921831 | Method for preparing active carbons | Masayuki Nakai, Takeshi Yoshida | 1990-05-01 |
| 4849021 | Process for producting coal fillers | Masayuki Nakai, Kenji Uesugi | 1989-07-18 |