Sulfam(na)phthaleins
US4178446A · kind A · utility
6Cited by
1References
40Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1977 |
| Grant date | Dec 11, 1979 |
| Priority date | — |
| Expiry date | Sep 23, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C8/48
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
This invention relates to phenol sulfam(na)phthaleins possessing a ##STR1## group wherein Y represents an electron-withdrawing group substituted on the N atom of the sulfam(na)phthalein ring, which compounds find utility as photographic optical filter agents and filter agent precursors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.