Patent ID: 6558893
Filing Date: 2003-05-06
Classification: G03C

Abstract:
A silver halide photographic material comprising at least one silver halide emulsion comprising silver halide grains having associated therewith a combination of two or more dyes comprising:(a) a first dye which is a cyanine dye of formula Ia and has a net charge of zero or âˆ’1 â€ƒwherein: E1 and E2 may be the same or different and represent the atoms necessary to form a substituted or unsubstituted heterocyclic ring which is a basic nucleus each J independently represents a substituted or unsubstituted methine group; q is a positive integer of from 1 to 4; p and r each independently represents 0 or 1; D1 and D2 each independently represents substituted or unsubstituted alkyl or substituted or unsubstituted aryl and at least one of D1 and D2 contains an anionic substituent; and W1 is one or more a counterions as necessary to balance the charge; (b) a second dye which has at least one substituent that has a positive charge, and is a cyanine dye a merocyanine dye, arylidene dye, complex cyanine dye, complex merocyanine dye, homopolar cyanine dye, hemicyanine dye, styryl dye, hemioxonol dye, oxonol dye, anthraquinone dye, triphenylmethane dye, azo dye, azomethines, or a coumarin dye, with the proviso that if the second dye is a cyanine dye, it is of formula IIa: â€ƒwherein: E1â€² and E2â€² may be the same or different and represent the atoms necessary to form a substituted or unsubstituted heterocyclic ring which is a basic nucleus, with the proviso that E1â€² and E2â€² of formula IIa are not the same as E1 and E2 of formula (Ia); each Jâ€² independently represents a substituted or unsubstituted methine group; qâ€² is a positive integer of from 1 to 4; pâ€² and râ€² each independently represents 0 or 1; D3 and D4 each independently represents substituted or unsubstituted alkyl or substituted or unsubstituted aryl and at least one of E1â€², E2â€², Jâ€² or D3 and D4 contains a cationic substituent; W2 is one or more a counterions as necessary to balance the charge; and wherein (c) the wavelength of maximum light absorption, in nanometers (nm), of the first dye and the wavelength of maximum light absorption of the second dye differ by at least 10 nm.