Phthalide derivatives and recording system utilizing the same
US4658276A · kind A · utility
8Cited by
1References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1986 |
| Grant date | Apr 14, 1987 |
| Priority date | — |
| Expiry date | Jun 11, 2006 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D407/12
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A new phthalide derivative useful as a colorless chromogenic material has the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 have the same meaning as defined hereinbefore.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.