Disulfonyl silver halide solvents substituted with piperazine at one sulfonyl group
AssigneePolaroid Corporation
InventorRichard B. Greenwald
Life of this patent
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Abstract
Alkanes containing an intralinear sulfonyl group and an intralinear 1-piperazinylsulfonamido group separated by a single carbon substituted with at least one hydrogen atom are employed as silver halide solvents in photographic processes and compositions.
Claims49
A photographic processing composition comprising an aqueous alkaline processing solution having dissolved therein a silver halide developing agent and as a silver halide solvent, a compound of the formula ##STR11## wherein R.sup.1 is lower alkyl, R.sup.2 is hydrogen, lower alkyl or --CH.sub.2).sub.m S--R.sup.o wherein R.sup.o is lower alkyl and m is a whole number 2 to 5;
- and X represents the residue of a 1-piperazine.
A photographic process for forming a water-soluble complex silver salt with the unexposed and undeveloped silver halide of an imagewise exposed and developed but unfixed photosensitive silver halide layer carried on a support which comprises treating said silver halide layer with an aqueous alkaline processing composition including therein as a silver halide solvent, a compound of the formula ##STR18## wherein R.sup.1 is lower alkyl, R.sup.2 is hydrogen, lower alkyl or --CH.sub.2).sub.m S--R.sup.o wherein R.sup.o is lower alkyl and m is a whole number 2 to 5;
- and X represents the residue of a 1-piperazine.
A diffusion transfer photographic process comprising the steps of:
- 1. reacting exposed silver halide of an imagewise exposed photosensitive silver halide emulsion layer carried on a support with a silver halide developing agent in aqueous alkaline solution;
- 2. reacting unreduced silver halide of said photosensitive emulsion with as a silver halide solvent, a compound of the formula ##STR25## wherein R.sup.1 is lower alkyl, R.sup.2 is hydrogen, lower alkyl or --CH.sub.2)S--R.sup.o wherein R.sup.o is lower alkyl and m is a whole number 2 to 5;
- and X represents the residue of a 1-piperazine to form a complex silver salt that is soluble in said alkaline solution;
- 3. transferring said complex silver salt to a superposed image-receiving layer;
- and
- 4. reducing said transferred complex silver salt to provide a silver image.
A photographic product which comprises a first sheet-like element comprising a photosensitive silver halide emulsion layer on a support;
- a second sheet-like element adapted to be superposed with said first sheet-like element and means for retaining an aqueous alkaline processing solution so positioned as to distribute said processing solution between said first and second sheet-like elements, at least one of said elements and said processing solution containing a silver halide solvent which forms a silver complex soluble in said aqueous alkaline solution, said silver halide solvent being a compound of the formula ##STR32## wherein R.sup.1 is lower alkyl, R.sup.2 is hydrogen, lower alkyl or --CH.sub.2).sub.m S--R.sup.o wherein R.sup.o is lower alkyl and m is a whole number 2 to 5;
- and X represents the residue of a 1-piperazine, said product including a silver halide developing agent in said processing composition.
Dependencies are inferred from the claim text.