High tabularity high chloride emulsions with inherently stable grain faces
AssigneeEastman Kodak Company
InventorJoe E. Maskasky
Life of this patent
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Abstract
A radiation sensitive emulsion is disclosed containing a silver halide grain population internally free of iodide at the site of grain nucleation comprised of at least 50 mole percent chloride, based on total silver forming the grain population, in which greater than 30 percent of the grain population projected area is accounted for by tabular grains having a mean thickness of less than 0.3 .mu.m. The tabular grains combine high tabularities and relatively high aspect ratios with exceptional stability imparted by parallel major faces lying in {100} crystallographic planes.
Claims12
A radiation sensitive emulsion containing a silver halide grain population internally free of iodide at the site of grain nucleation and comprised of at least 50 mole percent chloride, based on total silver forming the grain population, in which greater than 30 percent of the grain population projected area is accounted for by tabular grains having a mean thickness of less than 0.3 .mu.m,
- Characterized in that the tabular grains
- (a) have parallel major faces lying in {100} crystallographic planes,
- (b) have an average aspect ratio (ECD/t) in the range of from greater than 7.5 to 50, and
- (c) have an average tabularity (ECD/t.sup.2) in the range of greater than 25 to 1000,
- where
- ECD is the mean effective circular diameter of the tabular grains in .mu.m and
- t is the mean thickness of the tabular grains in .mu.m.
Dependencies are inferred from the claim text.