US 4,535,051 AGranted

Photographic products and processes with color shifted dye

AssigneePolaroid Corporation

InventorsMyron S. Simon, David P. Waller

Life of this patent

Estimating the term…

Loading patent…

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.

Claims21

Dependent claims

A photographic color process which provides a dye image comprising the steps of photoexposing a photosensitive element containing a silver halide emulsion, said silver halide emulsion having associated therewith a color shifted precursor of a preformed image dye, developing said exposed silver halide emulsion to form an image in developed silver and an imagewise distribution of silver ions and/or soluble silver complex in the partially developed and undeveloped areas of said emulsion, and forming as a function of said development a color image in dye from said color shifted precursor, said color shifted precursor having at least one ##STR35## group wherein R is hydrogen, alkyl, provided that the .alpha.-carbon is not attached to a hydrogen atom, or aryl;

R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are each independently hydrogen, alkyl or aryl;
n is 0 or 1;
and T is a moiety containing a thiazolidin-2-yl group, said thiazolidin-2-yl group being capable of undergoing cleavage in the presence of said silver ions and/or soluble silver complex, said moiety maintaining said color shifted precursor in its color shifted form at least until said thiazolidin-2-yl group undergoes said cleavage.

Dependencies are inferred from the claim text.