Fluoran compounds and recording sheet containing them
Abstract
Abstract A fluoran compound represented by the formula, ##STR1## WHEREIN R 1 , R 2 , R 3 and R 4 are each hydrogen, substituted or unsubstituted lower alkyl, lower alkenyl, or lower alkynyl, ##STR2## GROUP (WHEREIN X is hydrogen, halogen, lower alkyl, lower alkoxy, di-lower alkylamino or --COOR a group in which R a is lower alkyl, and l is an integer of 1 to 4), or R 1 and R 2 , or R 3 and R 4 , taken together, may form a heterocyclic ring; Y is the same atom or group as X but independent of X; D is a benzene or naphthalene nucleus; Z is hydrogen or halogen; and m and n are each an integer of 1 to 4, is useful as a coloring material for record material systems such as pressure-sensitive copying paper or heat-sensitive copying paper, wherein colored images are formed by an electron donor-accepter color-forming reaction between a coloring material and an acidic material.
Inventors
- 👤 Seiji Hotta
- 👤 Yukiaki Ito
Bibliographic Details
Claims Analysis
Total Claims: 15References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-05-28 | 1982-11-27 | 1983-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-28 | 1986-11-27 | 1987-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-28 | 1990-11-27 | 1991-05-29 | $7700.00 | Window Closed / Lapsed |