Type of modified gelatin and its use in a DTR material

摘要

A modified gelatin is disclosed wherein part of the free carboxyl groups is replaced by modifiers having more acid end-standing groups chosen from -SO3M, -OSO3M, -SSO3M, -OPO(OH)2, -OPO(OH)(OR2), -PO(OH)2, -PO(OH)(OR2). In a preferred embodiment such a modified gelatin is incorporated in a DTR photographic material which after processing can serve as a lithographic printing plate. Thanks to the more hydrophilic character of the modified gelatin the differentiation between printing and non-printing areas is improved and toning at printing start-up is reduced.