Issued Patents All Time
Showing 1–6 of 6 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4954631 | Fluoran compounds and color forming recording materials using same | Takeo Obitsu, Yutaka Ohnishi, Minoru Koguchi, Mitsuhiro Yanagita, Nobuyuki Hirai | 1990-09-04 |
| 4826806 | Fluoran compounds and color forming recording materials using same | Takeo Obitsu, Yutaka Ohnishi, Minoru Koguchi, Mitsuhiro Yanagita, Nobuyuki Hirai | 1989-05-02 |
| 4794069 | Spirobenzanthracene phthalide compounds, processes for preparing same and color forming recording materials containing said compounds | Yutaka Ohnishi, Toshiyuki Tanaka, Minoru Koguchi, Takeo Obitsu | 1988-12-27 |
| 4695640 | Addition compound of fluoran compounds and ketone | Masakichi Yahagi, Tetsuo Igaki, Kimiaki Kinoshita, Morikuni Saito, Toshiyuki Yamashita +1 more | 1987-09-22 |
| 4616239 | 4-hydroxy-4'-isopropoxydiphenylsulfone and its use for color-developable recording material | Masakichi Yahagi, Tetsuo Igaki, Kosaku Morita, Kimiaki Kinoshita, Masashi Enokiya +2 more | 1986-10-07 |
| 4568766 | 4-Hydroxy-4'-isopropoxydiphenylsulfone and its use for color-developable recording material | Masakichi Yahagi, Tetsuo Igaki, Kosaku Morita, Kimiaki Kinoshita, Masashi Enokiya +2 more | 1986-02-04 |