Photographic tanning developer formulation
AssigneeMinnesota Mining and Manufacturing Company
InventorGebran J. Sabongi
Life of this patent
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Abstract
An alkaline aqueous tanning developing solution for photographic image development comprising at least one hydroxylamine derivative. Preferred formulations may also contain at least one water-miscible polyhydroxy aliphatic organic solvent and/or a developing agent which comprises a polyhydroxybenzene compound having at least two hydroxy groups and at least one electron withdrawing and good leaving group suitable for nucleophilic addition.
Claims10
A tanning developer solution suitable for forming tanned images in an exposed silver halide gelatin emulsion layer in an imagewise fashion wherein said developer solution is an aqueous alkaline solution substantially free of sulfite and comprising;
- at least one soluble hydroxylamine derivative which is capable of reducing or eliminating air-induced non-imagewise hardening of said gelatin, said hydroxylamine derivative having the general formula:
- R.sub.1 (R.sub.2)NOR.sub.3,
- wherein
- R.sub.1 and R.sub.3, which may be the same or different, are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a heterocyclic group;
- and
- R.sub.2 is R.sub.4 CO-, wherein R.sub.4 is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group, or a heterocyclic group.
A tanning developer solution suitable for forming tanned images in an exposed silver halide gelatin emulsion layer in an imagewise fashion wherein said developer solution is an aqueous alkaline solution substantially free of sulfite and comprising;
- at least one soluble hydroxylamine derivative which is capable of reducing or eliminating air-induced non-imagewise hardening of said gelatin;
- and
- a developing agent which comprises a polyhydroxybenzene derivative having at least two hydroxy groups and at least one electron withdrawing and good leaving group suitable for nucleophilic addition.
Dependencies are inferred from the claim text.