Photographic products and processes
US4631344A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1985 |
| Grant date | Dec 23, 1986 |
| Priority date | — |
| Expiry date | Apr 29, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C8/10
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Photographic products and processes for the imagewise generation of a dye from a color shifted dye precursor of a preformed image dye, said precursor having at least one ##STR1## group, wherein R is hydrogen, alkyl, provided that the .alpha.-carbon does not have a hydrogen atom attached thereto, aryl such as phenyl or substituted phenyl, e.g. p-nitrophenyl, or heterocyclic such as pyridine; R.sub.1 -R.sub.6 are hydrogen, alkyl, preferably having from 1 to 6 carbon atoms, or aryl; n is 0 or 1; and T is a moiety containing a thiazolidin-2-yl group which upon silver-assisted cleavage of said thiazolidin-2-yl group results in the formation of a ##STR2## group, which may be protonated under the reaction conditions, followed by cleavage of said ##STR3## which cleavage is anchimerically assisted or accelerated by said ##STR4## to provide after protonation, an ##STR5## group in a dye chromophore. In a preferred embodiment the precursor is a substantially colorless compound.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.