Sun Chemical Corporation

Kodak Polychrome Graphics, Gmbh

Syeda Husain

John F Pilot

Allan P Piechowski

Burton H Waxman

Penny M Mullen

Shirley M Madamba

Rajendra J Shah

Nucleating agents that promote high contrast in photographic films are disclosed. The nucleating agents are aryl sulfonamido hydrazides having pyridinium, phosphonium or cycloalkenylpyridinium functional groups. The nucleating agents increase the speed and contrast of graphic arts films and improve dot quality in halftone applications. Boosters are not required to obtain good dot quality and photographic speed.

Nucleating agents for graphic arts films

Photographic film nucleating agents comprising aryl sulfonamidophenyl hydrazides containing alkene, alkadienyl, alkapolyenyl or cycloalkenyl substituted pyridinium functionality; these nucleators produce better dot quality and superior contrast characteristics in image-wise exposed film elements and wider compatibility with standard rapid access developers and obviate the need to include boosters in the film or in the developer.

Photographic contrast promoting agents

The inclusion of isothiouronium functionality onto hydrazide derivatives results in the formation of nucleating agents for lithographic films that produce high contrast and speed with excellent dot quality as required for halftone applications. The level of performance of the nucleators of the invention is sufficiently high that the need to incorporate amine boosters in the lithographic film elements or developers is not required. The novel nucleators have the formula ##STR1## wherein R is hydrogen, C.sub.1 -C.sub.10 alkyl, substituted or unsubstituted carbamoyl, or alkoxy or aryloxy carbonyl; Y is substituted or unsubstituted divalent aryl, and Q is an isothiouronium salt moiety.

Isothiouronium salts as photographic nucleating agents

Novel compounds have been discovered that are particularly effective as nucleation accelerators or boosters when employed with hydrazide nucleators in the formulation of silver halide emulsions for lithographic film. The novel compounds contain bis ureido groups joined by an alkyleneoxy moiety or recurring alkyleneoxy moieties. The 2-nitrogen of each ureido group can carry groups comprising hydrogen, aryl, alkyl or dialkylaminoalkyl, alike or different.

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Middletown, NJ, United States of America

Syeda Husain