Issued Patents 1989
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4835134 | Color-developing sheet for pressure-sensitive sheets | Hiroaki Umeda, Mamoru Suzuki, Akira Hasegawa | 1989-05-30 |
| 4835135 | Color-developing sheet for pressure-sensitive recording sheets | Hiroaki Umeda, Mamoru Suzuki, Akira Hasegawa | 1989-05-30 |
| 4833119 | Color-developing sheet for pressure-sensitive recording sheets | Hiroaki Umeda, Mamoru Suzuki, Akira Hasegawa | 1989-05-23 |
| 4806521 | Color-developing agent for pressure-sensitive recording sheet and color-developing sheet thereof | Hiroaki Umeda, Mamoru Suzuki, Akira Hasegawa | 1989-02-21 |