Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4841037 | Amino sulfonaphtholtrisazo compounds and recording liquids containing the same | Tokuya Ohta, Masatsune Kobayashi, Yuko Suga, Konoe Miura, Tomio Yoneyama | 1989-06-20 |
| 4808192 | Process for preparation of water soluble dyes containing lithium sulfonate group or ammonium sulfonate group by cation exchange, neutralization and reverse osmosis | Yoshihiro Narita, Hideo Sano | 1989-02-28 |