Modified peptizer twinned grain silver halide emulsions and processes for their preparation
AssigneeEastman Kodak Company
InventorsScott A. King, Philip I. Rose, Joe E. Maskasky
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Abstract
The present invention is directed to a process of precipitating for use in photography a silver halide emulsion employing a gelatino-peptizer containing alkylated methionine and to an emulsion produced by this process. A variety of advantages can be realized, including an increase in the population of twinned grains and a higher yield of thin tabular grains.
Claims21
a photographic emulsion comprising silver halide grains and a gelatino-peptizer, characterized in that
- at least 50 percent of the silver halide grains, based on total grain projected area, contain twin planes and
- the gelatino-peptizer contains alkylated methionine.
A process comprising forming silver halide grains in the presence of a gelatino-peptizer under conditions which favor the formation of at least some grains containing twin planes, wherein the gelatino-peptizer initially contains methionine,
- characterized in that the methionine of the gelatino-peptizer is at least partially alkylated prior forming the silver halide grains, so that the proportion of twin plane containing grains formed is increased.
Dependencies are inferred from the claim text.