Issued Patents All Time
Showing 1–5 of 5 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4845245 | Process for producing 3,3-bis-(4-dimethylaminophenyl)-6-dimethylaminophthalide | Hajime Kawai, Katsuhiko Tsunemitsu | 1989-07-04 |
| 4835291 | Divinyl compounds and chromogenic recording-material prepared by using thereof | Hajime Kawai, Youji Shimizu, Seiichi Nieda, Kazuhiko Gendai, Katsuhiko Tsunemitsu | 1989-05-30 |
| 4808567 | Divinyl compounds and chromogenic recording-material prepared by using thereof | Hajime Kawai, Youji Shimizu, Seiichi Nieda, Kazuhiko Gendai, Katsuhiko Tsunemitsu | 1989-02-28 |
| 4564679 | Chromogenic compounds | Hajime Kawai, Yasushi Nakai, Katsuhiko Tsunemitsu | 1986-01-14 |
| 4444591 | Chromogenic compounds and the use thereof as color former in copying or recording materials | Hajime Kawai, Katsuhiko Tsunemitsu, Yoji Shimizu | 1984-04-24 |