PH Sensitive dyes containing a phenolate group
US3976659A · kind A · utility
2Cited by
1References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 28, 1975 |
| Grant date | Aug 24, 1976 |
| Priority date | — |
| Expiry date | Aug 28, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C8/48
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
This invention relates to a new class of pH sensitive indicator dyes useful as optical filter agents in photographic processes to protect a selectively exposed photosensitive material from further exposure during processing in the presence of incident light. Such dyes contain a phenolate group as the ring-closing moiety and are represented by the compounds ##SPC1## Wherein R is hydrogen, alkyl, aryl, aralkyl or alkaryl, R.sup.1 and R.sup.2 the same are hydrogen, chloro or nitro, and R.sup.3 is hydrogen, carboxy, sulfonamido, sulfamoyl, or alkoxy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.