Eastman-kodak Company

Thomas R Dobles

Richard L Parton

David A Stegman

Kenneth Joseph Reed

Steven G Link

Paul B Gilman, Jr

Sang H Kim

John D Lewis

Teresa A Smith

Donald R Diehl

Margaret Jones Helber

John D Mee

Lal C Vishwakarma

Harry J Price

Pamela M Ferguson

Karen J Klingman

Heidi E Dankosh

Marian S Henry

Nona Veith Spitzner

Linda J Knapp

David A Dumont

Bruce E Kahn

A photographic element comprising at least one silver halide emulsion layer in which the silver halide has been sensitized with a first blue sensitizing dye having a .lambda..sub.1 less than or equal to about 475 nm and a second blue sensitizing dye having a .lambda..sub.2, wherein .lambda..sub.1 is longer than .lambda..sub.2 and .lambda..sub.1 and .lambda..sub.2 are separated by an energy gap, .DELTA.E, which does not exceed 0.12 eV, where .DELTA.E is defined by the following relationship: ##EQU1## wherein .lambda..sub.1 is the wavelength in nanometers (nm) of maximum absorption of a silver halide emulsion sensitized with the first dye and .lambda..sub.2 is the wavelength of maximum absorption of a silver halide emulsion sensitized with the second dye, with the proviso that neither the first nor the second dye contains selenium.

Photographic element comprising a mixture of sensitizing dyes

A photographic element comprises at least one silver halide emulsion layer in which: a) the silver halide has been spectrally sensitized with a first blue sensitizing dye having a .lambda..sub.1 less than or equal to about 475 nm and a second blue sensitizing dye having a .lambda..sub.2, wherein the following relationship is met: ##EQU1## wherein .lambda..sub.1 is the wavelength in nanometers (nm) of maximum absorption of a silver halide emulsion sensitized with the first dye and .lambda..sub.2 is the wavelength of maximum absorption of a silver halide emulsion sensitized with the second dye, with the proviso that neither the first nor the second dye contains selenium. The silver halide emulsion of said layer is chemically sensitized with a gold(I) compound and preferably with the combination of a gold compound and a disulfide compound; and b) the silver halide has been chemically sensitized with a gold compound of formula (I):

A photographic element having a silver halide emulsion spectrally sensitized to blue light by a dye of formula (I) to have a maximum blue sensitivity at less than 485 nm. The dye allows the element to have good color reproduction while still providing good speed response despite the shorter blue sensitivity. Formula (I) is: ##STR1## wherein: X and X' each independently represent the atoms necessary to complete a thiazole, benzothiazole, naphthothiazole, oxazole, benzoxazole, naphthoxazole, selenazole, benzoselenazole, naphthoselenazole, imidazole, benzimidazole, or naphtho-imidazole, and X may be further substituted and X' substituted or unsubstituted;

Blue sensitizing dyes with heterocyclic substituents

A supersensitizing dye combination for silver halide photographic materials is disclosed. The combination is of a first dye according to the formula: ##STR1## Z.sub.1 and Z.sub.2 each independently represents the atoms necessary to complete a substituted or unsubstituted heterocyclic nucleus,

Sensitizing dye combination for photographic materials

A photographic element which has a blue sensitive emulsion with broad blue spectral coverage and yet, good speed and low fog. The element has a blue sensitive silver halide tabular grain emulsion which has a tabularity of at least 25 sensitized with a dye of formula (I) and a dye of formula (II), wherein the formula (I) dye on the emulsion has a peak sensitization of between 400-445 nm and the formula (II) dye on the emulsion has a peak sensitization of between 446-500 nm: ##STR1## wherein: Z.sub.1, Z.sub.2, Z.sub.3 and Z.sub.4 independently represent the atoms necessary to complete a substituted or unsubstituted benzene or naphthylene;

Photographic elements containing particular blue sensitized tabular

A photographic element having a silver halide emulsion sensitized by dye of the formula I: ##STR1## wherein: R.sup.1 represents a substituted or unsubstituted aromatic or heteroaromatic group, a substituted or unsubstituted alkyl or H; R.sup.2 represents a substituted or unsubstituted alkyl, alkenyl, aryl, aralkyl, or H; E.sup.1 represents an electron withdrawing group; Z represents the non-metallic atoms required to complete a substituted or unsubstituted ring system containing at least one 5- or 6-membered heterocyclic nucleus; L.sup.1, L.sup.2, L.sup.5 and L.sup.6 independently represent a substituted or unsubstituted methine; m may be 0, 1, 2 or 3; n may be 0 or 1.

Photographic elements containing particular sensitizing dyes

A novel red-sensitizing dye compound has a structure which contains a pentamethine oxonol chromophore linked to one or two cyanine chromophores. A photographic element comprises a support upon which is coated a silver halide emulsion layer comprising cubic silver halide crystals and said red-sensitizing dye compound.

Dye compound and photographic element containing same

A variable contrast photographic element containing a light sensitive silver halide emulsion layer is disclosed wherein the silver halide is sensitized with a benzimidazolooxacarbocyanine dye of the following formula (I) in an amount less than that required to impart maximum sensitivity to all of the silver halide in the emulsion. ##STR1## In formula (I), R.sup.1, R.sup.2, R.sup.6 and R.sup.7 each independently represent hydrogen, halogen, hydroxy, or substituted or unsubstituted alkyl, alkenyl, alkoxy, alkylamino, alkylthio, aryl, aryloxy, arylamino, or arylthio. R.sup.3 and R.sup.4 each independently represent substituted or unsubstituted alkyl. R.sup.5 represents a substituent containing an electron withdrawing group. X represents a counterion as needed to balance the charge of the molecule. Use of dyes of formula (I) having an R.sup.5 substituent which contains an electron withdrawing group has been found to beneficially reduce the sensitivity of variable contrast photographic elements at wavelengths longer than 570 nm, thereby enhancing safelight tolerance, while still maintaining good spectral sensitivity at wavelengths in the green region less than 560 nm.

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Hilton, NY, United States of America

Thomas R Dobles