Issued Patents All Time
Showing 1–12 of 12 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5017710 | Fluoran compound and coloring recording material using it | Tetsuo Igaki, Akio Kaneko, Sumio Manaka | 1991-05-21 |
| 4695640 | Addition compound of fluoran compounds and ketone | Masakichi Yahagi, Tetsuo Igaki, Shinji Yoshinaka, Morikuni Saito, Toshiyuki Yamashita +1 more | 1987-09-22 |
| 4687862 | Fluoran compounds | Takeo Obitsu, Tetsuo Igaki, Morio Nanbu, Shinichi Satoh | 1987-08-18 |
| 4680598 | Chromogenic materials employing fluoran compounds | Takeo Obitsu, Tetsuo Igaki, Morio Nanbu, Shinichi Satoh | 1987-07-14 |
| 4668967 | Fluoran compound and color forming record materials using the same | Masakichi Yahagi, Takeo Obitsu, Tetsuo Igaki, Kazuyuki Horisawa, Morio Nanbu +1 more | 1987-05-26 |
| 4665199 | 3-N-isobutylethylamino-6-methyl-7-phenylaminofluoran | Masakichi Yahagi, Tetsuo Igaki, Sinzi Yoshinaka, Kousaku Morita, Morikuni Saito | 1987-05-12 |
| 4642357 | Chromogenic recording materials | Masakichi Yahagi, Tetsuo Igaki, Sinzi Yosinaka, Kousaku Morita, Morikuni Saito | 1987-02-10 |
| 4616239 | 4-hydroxy-4'-isopropoxydiphenylsulfone and its use for color-developable recording material | Masakichi Yahagi, Tetsuo Igaki, Shinji Yoshinaka, Kosaku Morita, Masashi Enokiya +2 more | 1986-10-07 |
| 4613879 | Chromogenic recording materials | Masakichi Yahagi, Tetsuo Igaki, Sinzi Yoshinaka, Kousaku Morita, Morikuni Saito | 1986-09-23 |
| 4590498 | Chromogenic recording materials | Masakichi Yahagi, Tetsuo Igaki, Sinzi Yosinaka, Kousaku Morita, Morikuni Saito | 1986-05-20 |
| 4568766 | 4-Hydroxy-4'-isopropoxydiphenylsulfone and its use for color-developable recording material | Masakichi Yahagi, Tetsuo Igaki, Shinji Yoshinaka, Kosaku Morita, Masashi Enokiya +2 more | 1986-02-04 |
| 4503446 | Heat-sensitive color-developing composition | Masakichi Yahagi, Masashi Enokiya | 1985-03-05 |