Photographic element including superimposed silver halide layers of different speeds

Abstract

Photographic elements are provided which feature a support having coated thereon a first photographic silver halide emulsion layer containing image-forming coupler and development inhibitor-releasing coupler; and, a second silver halide emulsion layer containing photographic image-forming coupler, the second layer having a faster effective speed sensitivity than the first layer. Such elements have high contrast for faint images and an extended latitude of low contrast for bright images.

We claim: 
     
       1. A photographic element comprising a support having coated thereon: a. a first photographic silver halide emulsion layer containing (1) nondiffusible photographic coupler which forms image dye and (2) a development inhibitor-releasing photographic coupler; and,   b. a second photographic silver halide emulsion layer containing nondiffusible photographic coupler which forms image dye, said second layer having a faster effective speed sensitivity than said first layer.   
     
     
       2. A photographic element as defined in claim 1 wherein each of said couplers has one of the following structural formulas: ##EQU5## ##SPC2## wherein R 1 , X 1 , R 5 , R 6 , R 10 , R 11 , R 12  and R 13  each represents a group of the type employed in, respectively, open-chain ketomethylene couplers, 5-pyrazolone couplers, and phenolic couplers; and Y 1 , Y 2  and Y 3  each represents:   a. a member selected from the group consisting of hydrogen and a colorless coupling-off group to complete said image-forming coupler; .[.and.]. .Iadd.or .Iaddend.   b. a colorless group to complete said development inhibitor-releasing coupler.   
     
     
       3. A photographic element as defined in claim 1 wherein each of said couplers has one of the following structural formulas: ##EQU6## ##SPC3## wherein R 1  and R 5  each represents a member selected from the group consisting of alkyl, aryl, and a heterocyclic group containing at least one carbon atom selected from oxygen, sulfur and nitrogen; X 1  represents a member selected from the group consisting of cyano and carbamyl; R 6  represents a member selected from the group consisting of alkyl, carbamyl, amino, amido, benzamido, and alkamido; R 10  and R 11  each represents a member selected from the group consisting of hydrogen, alkyl, aryl, a heterocyclic group containing at least one hetero atom selected from oxygen, sulfur and nitrogen, amino, carbonamido, sulfonamido, sulfamyl, carbamyl, halogen, and alkoxy; R 12  and R 13  when taken together, represents the atoms required to complete a benzo group, and when taken separately, each represents a value selected from those given for R 10  and R 11  ; and, said Y 1 , Y 2  and Y 3  each represents:   a. a member selected from the group consisting of hydrogen, halogen, a thiocyano group, an acyloxy group, an aryloxy group, a cyclooxy group, and, when said R 12  and R 13  represent the atoms to complete a benzo group, Y 3  represents any of the foregoing groups given for Y 1  and Y 2  except aryloxy, and can in addition represent a cycloimido group, to complete said photographic image forming coupler; .[.and.]. .Iadd.or .Iaddend.   b. a monothio group selected from an orthoamino-substituted arylmonothio group; an orthonitro-substituted arylmonothio group; and, a heterocyclic radical containing at least one hetero atom selected from oxygen, sulfur and nitrogen, to complete said development inhibitor-releasing coupler.   
     
     
       4. A photographic element as defined in claim 3 wherein said Y 1 , Y 2  and Y 3  each represents a heterocyclic monothio radical containing from one to four heteronitrogen atoms, to complete said development inhibitor-releasing coupler. 
     
     
       5. A photographic element as defined in claim 4 wherein said Y 1 , Y 2  and Y 3  each represents a member selected from the group consisting of: a 2-nitrophenylthio group; a 2-aminophenylthio group; a 5-tetrazolylthio group; a 2-benzothiazolylthio group; and, a 5-phenyl-1,3,4-oxadiazolylthio group, to complete said development inhibitor-releasing coupler. 
     
     
       6. A photographic element as defined in claim 3 wherein said second photographic silver halide emulsion layer produces an effective speed which is about 0.6 Log E faster than the effective speed of said first photographic silver halide emulsion. 
     
     
       7. A photographic element as defined in claim 3 wherein said photographic silver halide emulsion layers and said support are separated by a nonimage-recording emulsion layer comprising silver halide grains which have an average diameter of less than about 1 micron. 
     
     
       8. A photographic element as defined in claim 7 wherein said nonimage-recording silver halide emulsion layer is coated at a thickness of from about 10 to 40 microns. 
     
     
       9. A photographic element comprising a support having coated thereon, in the order given: a. an unsensitized, nonimage-recording layer comprising gelatin having dispersed therein silver bromoiodide grains having an average diameter of about 0.1 to 1 micron;   b. a first panchromatically sensitized photographic gelatin silver bromoiodide emulsion layer containing the cyan image-forming coupler 1-hydroxy-2-[Δ(2',4'-di-tert-amylphenoxy)-N-butyl]-naphthamide and the development inhibitor-releasing coupler 1-hydroxy-4-(1-phenyl-5-tetrazolylthio)-2-[Δ-(2,4-di-tert-amyl-phenoxy)-N-butyl]naphthamide; and,   c. a second panchromatically sensitized photographic gelatin silver bromoiodide emulsion layer containing the cyan image forming coupler 1-hydroxy-2-[Δ(2',4'-di-tert-amylphenoxy)-N-butyl]-naphthamide, which layer produces an effective speed of about 0.6 Log E faster than said first silver halide emulsion layer.   
     
     
       10. A photographic element as defined in claim 3 wherein said photographic silver halide layers and said support are separated by a photographic antihalation layer. .Iadd. 11. A photographic element as in claim 1, wherein said second layer is free of development inhibitor-releasing photographic coupler. .Iaddend..Iadd. 12. A photographic element as in claim 11, wherein the amount of said non-diffusible photographic coupler which forms image dye in said second layer is smaller than the amount of said non-diffusible photographic coupler which forms image dye in said first layer. .Iaddend..Iadd. 13. A photographic element as in claim 3, wherein said second layer is free of development inhibitor-releasing photographic coupler. .Iaddend..Iadd. 14. A photographic element as in claim 13, wherein the amount of said non-diffusible photographic coupler which forms image dye in said second layer is smaller than the amount of said non-diffusible photographic coupler which forms image dye in said first layer. .Iaddend..Iadd. 15. A photographic element as in claim 5, wherein said second layer is free of development inhibitor-releasing photographic coupler. .Iaddend..Iadd. 16. A photographic element as in claim 15, wherein the amount of said non-diffusible photographic coupler which forms image dye in said second layer is smaller than the amount of said non-diffusible photographic coupler which forms image dye in said first layer. .Iaddend. .Iadd. 17. A photographic element comprising a support having coated thereon a. a first photographic silver halide emulsion layer containing (1) nondiffusible photographic coupler which forms image dye and (2) a development inhibitor-releasing photographic coupler; and,   b. a second photographic silver halide emulsion layer containing nondiffusible photographic coupler which forms image dye, said second layer having a faster effective speed sensitivity than said first layer, wherein each of said couplers has one of the following structural formulas: ##EQU7## ##EQU8## ##SPC4## wherein R 1 , X 1 , R 5 , R 6 , R 10 , R 11 , R 12  and R 13  each represents a group of the type employed in, respectively, open-chain ketomethylene couplers, 5-pyrazolone couplers, and phenolic couplers; and Y 1 , Y 2  and Y 3  each represents:     a. a member selected from the group consisting of hydrogen and a colorless coupling-off group to complete said image-forming coupler, or   a colorless group to complete said development inhibitor-releasing coupler; said second emulsion layer being substantially free of development inhibitor-releasing photographic coupler, said second emulsion layer being contiguous to said first emulsion layer and being positioned closer than said first emulsion layer to said support, and the effective speed of said second emulsion layer being from about 0.6 log E to about 1.2 log E faster     
     
     
        than that of said first emulsion layer. .Iaddend..Iadd. 18.  A photographic element as in claim 17, wherein said development inhibitor-releasing photographic coupler forms, upon reaction with oxidized color developer, a dye of the same color as said image dye; the amount of said development inhibitor-releasing photographic coupler in said first emulsion layer being from about 1 to about 10 mg per square foot. .Iaddend..Iadd. 19. A photographic element as in claim 18, wherein the amount of said non-diffusible photographic coupler which forms image dye in said second layer is smaller than amount of said non-diffusible photographic coupler which forms image dye in said first layer. .Iaddend..Iadd. 20. A photographic element as in claim 18, wherein the amount of said non-diffusible photographic coupler which forms image dye in said first layer is about three times the amount of said non-diffusible photographic coupler which forms image dye in said second layer. .Iaddend. .Iadd. 21. A photographic element as defined in claim 18, wherein said Y 1 , Y 2  and Y 3  each represents a heterocyclic monothio radical containing from one to four heteronitrogen atoms, to complete said development inhibitor-releasing coupler. .Iaddend..Iadd. 22. A photographic element as defined in claim 21, wherein said Y 1 , Y 2  and Y 3  each represents a member selected from the group consisting of: a 2-nitrophenylthio group; a 2-aminophenylthio group; a 5-tetrazolylthio group; a 2-benzothiazolylthio group; and a 5-phenyl 1,3,4-oxadiazolylthio group, to complete said development inhibitor-releasing coupler. .Iaddend..Iadd. 23. A photographic element as defined in claim 18, wherein said photographic silver halide emulsion layers and said support are separated by a nonimage-recording emulsion layer comprising silver halide grains which have an average diameter of less than about 1 micron. .Iaddend..Iadd. 24. A photographic element as defined in claim 23, wherein said nonimage-recording silver halide emulsion layer is coated at a thickness of from about 10 to 40 microns. .Iaddend..Iadd. 25. A photographic element as in claim 18, wherein said photographic silver halide layers and said support are separated by a photographic antihalation layer. .Iaddend.