Patent ID: 6451491
Filing Date: 2002-09-17
Classification: G03F

Abstract:
An imagewise exposed and developed photographic element having high contrast between image and removed non-image areas which comprises(a) a substrate; and (b) a photographic image on the substrate, which image has been produced by coating and drying a photosensitive composition on the substrate, imagewise exposing the photosensitive composition to actinic radiation and removing the non-image areas of the photosensitive compositiun to thereby uncover portions of the substrate underlaying the non-image areas while not removing the image areas; wherein the substrate under the removed non-image areas has a Hunter stimulus lightness value L ranging from about 35 to about 80, the images areas have an L value of from about 20 to about 60 and the difference between the L value for the substrate under the removed non-image areas and the L value for the image areas is at least about 15; wherein said photosensitive composition comprises an admixture of at least one light sensitive component diazonium compound or photopolymerizable composition, in an amount sufficient to form a uniform photosensitive composition; at least one aqueous alkaline soluble or swellable polymeric binder compound which is the reaction product of a hydroxy containing polymer and an anhydride in the presence of a catalytic amount of a tertiary amine catalyst, which binder is present in an amount sufficient to bind the photosensitive composition in a uniform admixture; and a colorant dispersion in an amount sufficient to uniformly color the photosensitive composition; said colorant dispersion comprising: i. at least one pigment; ii. a solvent composition which comprises at least one of a C1-C8 aliphatic alcohol, a mono- or di-C1-C8 alkylene glycol C1-C8 alkyl ether, or a cyclic ketone; and iii. at least one aqueous alkaline soluble or swellable polymeric compound which is the reaction product of a hydroxy containing polymer and all anhydride in the presence of a catalytic amount of a tertiary amine catalyst, wherein the pigment and the polymeric compound are present in a weight ratio of from about 0.75:1.25 to about 1.25:0.75 and wherein the solvent composition is present in an amount sufficient to form a uniform, stable dispersion.