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US 5,510,235 AGranted
Photographic elements comprising 2-phenylcarbamoyl-naphthol image-modifying couplers yielding dyes resistant to crystallization and reduction
AssigneeEastman Kodak Company
InventorsPaul B. Merkel, Jerrold N. Poslusny, Daniel L. Kapp, John R. Ross
Life of this patent
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Abstract
Photographic elements comprising certain 2-phenylcarbamoyl-1-naphthol couplers exhibit proper hue, a resistance to dye crystallization, and a resistance to leuco cyan dye formation. Such couplers can be utilized for their image-modifying effect and can contribute substantially to the overall dye density of an image.
Claims19
A photographic element comprising a support bearing (a) at least one silver halide emulsion and (b) at least one cyan dye-forming 2-phenylcarbamoyl-1-naphthol coupler having the structure ##STR16## wherein:
- R.sub.1 is selected from the group consisting of an alkoxy group, a phenoxy group and halogen;
- R.sub.2 is selected from the group consisting of an alkyl group, a phenyl group, an alkoxy group, a halogen, and an alkoxycarbonyl group;
- with the provisoes that when R.sub.2 is a halogen, R.sub.1 is an alkoxy or phenoxy group, and when R.sub.2 is an alkoxycarbonyl group, R.sub.1 is a phenoxy group;
- R.sub.3 is selected from hydrogen, and an alkyl group;
- R.sub.1, R.sub.2, and R.sub.3 together contain at least 3 carbon atoms;
- and
- Z is a coupling off group selected from the group consisting of a blocked dye moiety and a structure of the formula:
- --A--B--N.dbd.N--D
- wherein:
- A represents a divalent linking group which releases from the coupler upon reaction with oxidized developer to cleave Z from the remainder of the coupler;
- B is a divalent aromatic group;
- and
- D is an aryl or heteroaryl group.
10 more elements
Dependencies are inferred from the claim text.