Blocked photographically useful compounds and photographic compositions, elements and processes employing them
AssigneeEastman Kodak Company
InventorsJared B. Mooberry, William C. Archie, Jr.
Life of this patent
Estimating the term…
Abstract
Photographically useful compounds such as photographic reagents and photographic dyes are blocked with a grouping which, under alkaline conditions, is cleaved from the compound by an intramolecular nucleophilic displacement reaction. The compounds are resistant to unblocking under storage conditions, but are uniformly unblocked under conditions encountered during photographic processing.
Claims28
A photographic element comprising a support, at least one photosensitive silver halide emulsion layer and a blocked photographic reagent having the structure:
- PR-G'-E-X-NuP
- where:
- PR-G' is the residue of a photographic reagent, G' being oxygen, sulfur, selenium, phosphorous or nitrogen;
- E is an electrophilic group;
- NuP is a precursor of a nucleophilic group which, under alkaline conditions, is converted uniformly to a nucleophilic group;
- and
- X is a linking group for spatially relating E and NuP to enable them to undergo, after conversion of NuP to a nucleophilic group, an intramolecular nucleophilic displacement reaction which cleaves the bond between E and G';
- the blocked photographic reagent, under alkaline conditions encountered during processing of the silver halide emulsion layer, being uniformly unblocked, even if contacted with oxidized silver halide developing agent.
A photographic image transfer film unit for forming a dye image comprising:
- (a) a photosensitive element comprising a support having thereon at least one photosensitive silver halide emulsion layer having associated therewith an immobile dye releasing compound;
- and
- (b) a dye image-receiving layer;
- the film unit containing a blocked photographic reagent having the structure:
- PR-G'-E-X-NuP
- where:
- PR-G' is the residue of a photographic reagent, G' being oxygen, sulfur, selenium, phosphorous or nitrogen;
- E is an electrophilic group;
- NuP is a precursor of a nucleophilic group which, under alkaline conditions, is converted uniformly to a nucleophilic group;
- and
- X is a linking group for spatially relating E and NuP to enable them to undergo, after conversion of NuP to a nucleophilic group, an intramolecular nucleophilic displacement reaction which cleaves the bond between E and G';
- the blocked photographic reagent, under alkaline conditions encountered during processing of the silver halide emulsion layer, being uniformly unblocked, even if contacted with oxidized silver halide developing agent.
An image transfer dye image receiving element capable of being permeated by an alkaline processing composition, comprising a support having thereon a neutralizing layer, a timing layer and a dye image receiving layer, the element containing a blocked photographic reagent having the structure:
- PR-G'-E-X-NuP
- where:
- PR-G' is the residue of a photographic reagent, G' being oxygen, sulfur, selenium, phosphorous or nitrogen;
- E is an electrophilic group;
- NuP is a precursor of a nucleophilic group which, under alkaline conditions, is converted uniformly to a nucleophilic group;
- and
- X is a linking group for spatially relating E and NuP to enable them to undergo, after conversion of NuP to a nucleophilic group, an intramolecular nucleophilic displacement reaction which cleaves the bond between E and G';
- the photographic reagent, under alkaline conditions encountered during processing of a silver halide emulsion layer, being uniformly unblocked, even if contacted with oxidized silver halide developing agent.
Dependencies are inferred from the claim text.