Attachment of gelatin-grafted polymer particles to pre-precipitated silver halide grains
AssigneeEastman Kodak Company
InventorsMark A. Whitson, John D. Lewis, Tienteh Chen, Thomas J. Dannhauser, Pranab Bagchi
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Abstract
The invention describes silver halide packet emulsion grains or crystals that are conventionally precipitated using gelatin of a given isoelectric pH, surrounded by a layer of gelatin-grafted-polymer particles wherein the grafted gelatin has a different isoelectric pH and the said gelatin-grafted-polymer particles are optionally chemically bonded to the gelatin surrounding the silver halide microcrystals. Such packet emulsions can form the basis for a mixed-packet color photographic system.
Claims13
A photosensitive silver halide emulsion composition comprising in an aqueous medium:
- (a) silver halide-gelatin particles comprising silver halide grains, each surrounded by a layer of adsorbed peptizing gelatin wherein the peptizing gelatin has an isoelectric pH of P.sub.1 ;
- and
- (b) gelatin-grafted-polymer particles wherein the grafted gelatin has an isoelectric pH of P.sub.2 which is different than P.sub.1 ;
- wherein the gelatin-grafted-polymer particles are attached to the layer of peptizing gelatin surrounding the silver halide grains.
The composition of claim i wherein said gel-grafted polymer particles comprise grafted gelatin and a polymer selected from at least one member of the group consisting of:
- polymeric filter dye,
- polymeric development inhibitor release coupler,
- polymeric development inhibitor anchimeric release coupler,
- polymeric dye-forming coupler,
- polymeric ultraviolet radiation absorbing compound,
- polymeric development accelerator,
- polymeric developer,
- polymeric sensitizing dye,
- polymeric development inhibitors,
- polymeric antifoggants, and
- polymeric bleach accelerators.
Dependencies are inferred from the claim text.