Novel xanthene compounds and their photographic use
US4617402A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 1983 |
| Grant date | Oct 14, 1986 |
| Priority date | — |
| Expiry date | Sep 1, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C8/48
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In one embodiment, the present invention is concerned with novel xanthene compounds of the formula ##STR1## wherein each R.sup.1 is the same and is selected from ##STR2## R.sup.2 is alkyl, R.sup.3 is an electron-withdrawing group positioned ortho, meta or para to said N atom, R.sup.4 is hydrogen, alkyl or an electron-withdrawing group positioned ortho, meta or para to said N atom; R.sup.5 is alkyl; X is hydrogen, an electron-withdrawing group or an electron-donating group; and A is an anion. In another embodiment, the present invention is concerned with photographic products and processes employing these xanthene compounds, e.g., as photographic light-screening dyes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.