Photographic speed increasing and latent image stabilizing compounds, silver halide emulsions, and photographic elements
AssigneeEastman Kodak Company
InventorsRoger Lok, John P. Freeman, William N. Baum
Life of this patent
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Abstract
Photographic silver halide emulsions show increased speed and reduced latent image fading when a compound of the following structure is incorporated: ##STR1## wherein: X is --O--, --S--, --Se--, or ##STR2## Y.sup.1 and Y.sup.2 individually represent hydrogen or an aromatic nucleus or together represent the atoms completing a fused aromatic nucleus; Z is ##STR3## R is hydrogen or lower alkyl of from 1 to 5 carbon atoms; and R.sup.1 is hydrogen or methyl.
Claims16
A photographic silver halide emulsion containing a photographically effective amount of a compound represented by the formula ##STR26## wherein:
- X is --O--, --S--, --Se--, or ##STR27## Y.sup.1 and Y.sup.2 individually represent hydrogen or an aromatic nucleus or together represent the atoms completing a fused aromatic nucleus;
- Z is ##STR28## R is hydrogen or lower alkyl of from 1 to 5 carbon atoms;
- and R.sup.1 is hydrogen or methyl, provided that Y.sup.1 and Y.sup.2 individually represent hydrogen or an aromatic nucleus when R.sup.1 is hydrogen.
In a color photographic element comprising a support bearing at least one blue-sensitive silver halide emulsion layer having associated therewith a yellow dye-forming coupler, at least one green-sensitive silver halide emulsion layer having associated therewith a magenta dye-forming coupler, and at least one red-sensitive silver halide emulsion layer having associated therewith a cyan dye-forming coupler, the improvement wherein at least one of the silver halide emulsion layers contains a latent image stabilizing amount of a compound represented by the formula:
- ##STR29## wherein:
- X and Y complete a heterocyclic nucleus chosen from the class consisting of benzoxazole, benzothiazole, benzoselenazole, and benzimidazole;
- Z is ##STR30## and R is hydrogen or lower alkyl.
A process comprising incorporating in a photographic silver halide emulsion in a photographically effective amount a compound represented by the formula ##STR31## wherein:
- X is oxygen, sulfur, selenium, or nitrogen;
- Y.sup.1 and Y.sup.2 individually represent hydrogen or an aromatic nucleus or together represent the atoms necessary to complete a fused aromatic nucleus;
- Z is ##STR32## R is hydrogen or lower alkyl of from 1 to 5 carbon atoms;
- and R.sup.1 is hydrogen or methyl, provided that Y.sup.1 and Y.sup.2 individually represent hydrogen or an aromatic nucleus when R.sup.1 is hydrogen.
Dependencies are inferred from the claim text.