Nucleated high contrast photographic elements containing urea compounds which enhance speed and increase contrast
AssigneeEastman Kodak Company
InventorAnthony Adin
Life of this patent
Estimating the term…
Abstract
Silver halide photographic elements which are capable of high-contrast development and are especially useful in the field of graphic arts comprise surface latent image forming high-chloride silver halide grains and have incorporated therein a hydrazine compound which functions as a nucleator, an amino compound which functions as an incorporated booster, and a combination of a gold compound and a urea compound which functions as a chemical sensitizer. Urea compounds effective for this purpose are 1,1,3,3-tetra-substituted middle chalcogen urea compounds in which at least one substituent comprises a nucleophilic center.
Claims19
A silver halide photographic element adapted to form a high contrast image when developed with an aqueous alkaline developing solution;
- said element comprising:
- (1) surface latent image forming high-chloride silver halide grains,
- (2) a hydrazine compound that functions as a nucleator,
- (3) an amino compound that functions as an incorporated booster,
- (4) a gold compound that functions as a chemical sensitizer, and
- (5) a urea compound that functions as a chemical sensitizer, said urea compound being a 1,1,3,3-tetra-substituted middle chalcogen urea compound in which at least one substituent comprises a nucleophilic center.
A silver halide photographic element adapted to form a high contrast image when developed with an aqueous alkaline developing solution, said element comprising:
- (1) surface latent image forming high-chloride silver halide grains,
- (2) a hydrazine compound that functions as a nucleator, said hydrazine compound having the formula:
- ##STR27## (3) an amino compound that functions as an incorporated booster, said amino compound having the formula:
- ##STR28## where Pr represents n-propyl, (4) potassium tetrachloroaurate in an amount sufficient to serve as a chemical sensitizer, and
- (5) 1,3-dicarboxymethyl-1,3-dimethyl-2-thiourea in an amount sufficient to serve as a chemical sensitizer.
A silver halide photographic element adapted to form a high contrast image when developed with an aqueous alkaline developing solution, said element comprising:
- (1) surface latent image forming rhodium-doped AgClBr (70/30) silver halide grains,
- (2) a hydrazine compound that functions as a nucleator, said hydrazine compound having the formula:
- ##STR29## (3) an amino compound that functions as an incorporated booster, said amino compound having the formula:
- ##STR30## where Pr represents n-propyl, (4) potassium tetrachloroaurate in an amount sufficient to serve as a chemical sensitizer, and
- (5) 1,3-dicarboxymethyl-1,3-dimethyl-2-thiourea in an amount sufficient to serve as a chemical sensitizer.
Dependencies are inferred from the claim text.