Photographic system with salt of phenylmercaptoazole and quaternary radical
AssigneePolaroid Corporation
InventorsAvinash C. Mehta, Lloyd D. Taylor
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Abstract
There is described a photographic system wherein development of an exposed photosensitive element with an aqueous alkaline processing composition is effected in the presence of a compound which is a salt of a radical of a substituted phenylmercaptoazole complexed with a radical of a quaternary. The salts are either insoluble or have extremely low solubility in water and become soluble, and photographically active, in alkaline environment.
Claims20
A photographic element comprising a support and at least one layer thereon containing a silver halide emulsion having associated therewith a compound represented by the formula ##STR13## wherein X represents the nonmetallic atoms necessary to form a nucleus which completes a five- or six member heterocyclic moiety;
- R is either a group which has a pKa of from about 7 to about 14 which is ionizable to an anion and wherein the silver salt of the mercaptan resulting from dissociation of said compound is more soluble in the range within which R is ionized to an anion than it is below that pH range, or a precursor thereof;
- and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently alkyl, or R.sub.1 is --(CH.sub.2).sub.n --R.sub.5 and R.sub.2, R.sub.3 and R.sub.4, together with the nitrogen atom, form a six member heterocyclic ring;
- R.sub.5 is hydrogen, phenyl or substituted phenyl;
- and n is an integer of from 1 to 6.
A photographic product for use in forming a multicolor diffusion transfer image comprising a photosensitive element comprising a support carrying a blue-sensitive silver halide emulsion having a yellow image dye-providing material associated therewith, a green-sensitive silver halide emulsion having a magenta image dye-providing material associated therewith and a red-sensitive silver halide emulsion having a cyan image dye-providing material associated therewith, a second sheet-like element positioned in superposed or superposable relationship with said photosensitive element, an image receiving layer positioned in one of said elements, a rupturable container releasably holding an aqueous alkaline processing composition adapted, when distributed between a pair of predetermined layers carried by said photosensitive element and said second element, to develop said silver halide emulsions and provide a multicolor diffusion transfer image on said image receiving layer, at least one of said photosensitive and second elements including a compound represented by the formula ##STR16## wherein X represents the nonmetallic atoms necessary to form a nucleus which completes a five or six member heterocyclic moiety;
- R is either a group which has a pKa of from about 7 to about 14 which is ionizable to an anion and wherein the silver salt of the mercaptan resulting from dissociation of said compound is more soluble in the range within which R is ionized to an anion than it is below that pH range, or a precursor thereof;
- and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently alkyl, or R.sub.1 is --(CH.sub.2).sub.n --R.sub.5 and R.sub.2, R.sub.3 and R.sub.4, together with the nitrogen atom, form a six member heterocyclic ring;
- R.sub.5 is hydrogen, phenyl or substituted phenyl;
- and n is an integer of from 1 to 6.
A diffusion transfer film unit comprising:
- (a) a photosensitive element comprising a support, a silver halide emulsion in a layer carried by said support and an image dye-providing material in a layer carried by said support on the same side thereof as said silver halide emulsion;
- (b) a second sheet-like element adapted to be superposed on said photosensitive element during or after photoexposure;
- (c) an image receiving layer positioned in one of said photosensitive or second sheet-like element;
- (d) a rupturable container releasably holding an aqueous alkaline processing composition and so positioned as to be adapted to distribute said processing composition between predetermined layers of said elements;
- and
- (e) present in a least one of said photosensitive and second sheet-like elements a compound represented by the formula ##STR19## wherein X represents the nonmetallic atoms necessary to form a nucleus which completes a five or six member heterocyclic moiety;
- R is either a group which has a pKa of from about 7 to about 14 which is ionizable to an anion and wherein the silver salt of the mercaptan resulting from dissociation of said compound is more soluble in the range within which R is ionized to an anion than it is below that pH range, or a precursor thereof;
- and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently alkyl, or R.sub.1 is --(CH.sub.2).sub.n --R.sub.5 and R.sub.2, R.sub.3 and R.sub.4, together with the nitrogen atom, form a six member heterocyclic ring;
- R.sub.5 is hydrogen, phenyl or substituted phenyl;
- and n is an integer of from 1 to 6.
A diffusion transfer photographic process comprising exposing a film unit comprising a photosensitive element and a second element, said photosensitive element comprising a support carrying at least one silver halide emulsion having an image dye-providing material associated therewith, applying an aqueous alkaline processing composition to said exposed photosensitive element to the effect photosensitive element to the effect development and to form an imagewise distribution of said image dye-providing material as a function of development and transferring at least a portion of said imagewise distribution of image dye-providng material to an image receiving layer in superposed or superposable relationship to thereby provide a diffusion transfer image, at least one of said photosensitive and second elements including a compound represented by the formula ##STR22## wherein X represents the nonmetallic atoms necessary to form a nucleus which completes a five or six member heterocyclic moiety;
- R is either a group which has a pKa of from about 7 to about 14 which is ionizable to an anion and wherein the silver salt of the mercaptan resulting from dissociation of said compound is more soluble in the range within which R is ionized to an anion than it is below that pH range, or a precursor thereof;
- and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently alkyl, or R.sub.1 is --(CH.sub.2).sub.n --R.sub.5 and R.sub.2, R.sub.3 and R.sub.4, together with the nitrogen atom, form a six member heterocyclic ring;
- R.sub.5 is hydrogen, phenyl or substituted phenyl;
- and n is an integer of from 1 to 6.
Dependencies are inferred from the claim text.