Aminomethyl-substituted 1-naphthol phthalides and naphthalides
US3944569A · kind A · utility
0Cited by
2References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 27, 1973 |
| Grant date | Mar 16, 1976 |
| Priority date | — |
| Expiry date | Aug 27, 1993 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C8/48
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
This invention relates to a class of phthalein 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 comprise 3,3-disubstituted phthalides and 3,3-disubstituted naphthalides wherein the 3,3 substituents are p-hydroxy carbocyclic aryl radicals wherein one or both of the radicals possess a --CH.sub.2 --NRR' group ortho to the p-hydroxy group and the --CH.sub.2 --NRR' group(s) is capable of rendering the indicator dye substantially non-diffusible in aqueous solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.