Silver halide color photographic element and process containing leuco dyes
AssigneeEastman Kodak Company
InventorsThomas Edward Gompf, William Henry Faul
Life of this patent
Estimating the term…
Abstract
Color photographic elements, compositions and processes for producing color negative images are described which employ a leuco dye comprising the reaction product of a color forming coupler and a N,N-dialkyl-p-phenylenediamine having an electronegative group attached to the benzene ring. The leuco dye is stable against aerial oxidation and can be developed to its corresponding dye with certain black and white developing compositions.
Claims16
A color photosensitive element comprising a support having thereon at least one photosensitive silver halide emulsion layer containing a stabilized ballasted leuco dye represented by the following general formula:
- ##SPC7##
- where
- Ballast -- represents an organic radical of such molecular size and configuration as to render said leuco dye nondiffusible during development;
- R.sub.1 and R.sub.2 -- each represent an alkyl group of one to six carbon atoms;
- and
- X -- is selected from the group consisting of --CF.sub.3, --SO.sub.2 C.sub.6 H.sub.5, and --CONH.sub.2.
A method of forming a negative color image which comprises:
- 1. concurrently developing a silver and a dye image in the imagewise exposed areas of a photosensitive photographic element comprising a support having thereon at least one photosensitive silver halide emulsion layer containing a stabilized ballasted leuco dye which comprises the reaction product of a cyan color-forming coupler and a N,N-dialkyl-p-phenylenediamine having an electronegative group attached to the benzene ring, said electronegative group having the capability of deactivating the p-phenylenediamine group sufficiently to stabilize the leuco dye molecule against aerial oxidation;
- and
- 2. removing developed silver and residual silver halide to leave a cyan dye image in the imagewise exposed areas of said layer without oxidizing the leuco dye molecules in the non-exposed areas of said layer.
A method of forming a negative color image which comprises:
- 1. forming a silver and dye image in the imagewise exposed areas of a photosensitive photographic element comprising a support having thereon at least one photosensitive silver halide emulsion layer containing a stabilized ballasted leuco dye which comprises the reaction product of a cyan color-forming coupler and a N,N-dialkyl-p-phenylenediamine having an electronegative group attached to the benzene ring, said electronegative group having the capability of deactivating the p-phenylenediamine group sufficiently to stabilize the leuco dye molecule against aerial oxidation by contacting said exposed element with a developing composition containing a developing agent selected from the group consisting of 1-phenyl-3-pyrazolidone, 4-phenyl-4,4-dimethyl-3-pyrazolidone and 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone;
- and
- 2. removing developed silver and residual silver halide with a bleach-fix solution to leave a cyan dye image in the imagewise exposed areas of said layer.
Dependencies are inferred from the claim text.