Photographic developers
AssigneePolaroid Corporation
InventorRichard B. Greenwald
Life of this patent
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AssigneePolaroid Corporation
InventorRichard B. Greenwald
Estimating the term…
In one embodiment, the present invention relates to pyrazolidine derivatives, some of which are novel compounds, all of which are represented by the formula: ##STR1## wherein R.sup.1 and R.sup.2 taken individually, the same or different, are each hydrocarbon moieties containing up to about 20 carbon atoms selected from alkyl, aryl, aralkyl and alkaryl, which moieties may be unsubstituted or substituted with a substituent selected from carboalkoxyalkyl, aryl, alkyl, alkoxy, hydroalkyl, aminoalkyl, ketalalkyl and acetalalkyl, and R.sup.1 and R.sup.2 taken together represent the carbon atoms necessary to complete a cyclic moiety selected from: ##STR2## which cyclic moieties may be unsubstituted or substituted with the above-identified substituents; Y is --OH or --NH.sub.2 ; and X is --OH, --NH.sub.2, --NH.sub.2.Z where Z is a salt, or --NHR where R is alkyl or aryl. In another embodiment, the present invention is directed to the use of the above-denoted class of compounds as photographic silver halide developing agents and to photographic processes, products and compositions employing the same.
A photographic developer composition comprising an aqueous alkaline solution containing at least one silver halide developing agent selected from the group consisting of ##STR53## and salts thereof.
A method of developing a silver halide emulsion which comprises treating an exposed silver halide emulsion with an aqueous alkaline processing composition containing at least one silver halide developing agent selected from the group consisting of ##STR57## and salts thereof.
A photographic product comprising a support, a silver halide emulsion carried on said support and a silver halide developing agent selected from the group consisting of ##STR61## and salts thereof.
Dependencies are inferred from the claim text.