Thermally developable materials with improved speed and contrast and methods of use

摘要

Thermally developable materials include a reducing agent composition that can reduce silver ions and provide high contrast images. The reducing agent composition includes a) a hindered phenol reducing agent, an aromatic di- or tri-hydroxy compound, or mixtures thereof, and b) a thermally-releasable p-phenylenediamine co-developer that is represented by the following Structure I: R-NH-BLOCK (I) wherein R-NH- is a p-phenylenediamine group and BLOCK is a blocking group that is cleaved upon exposure to at least 120 DEG C for at least 5 seconds and comprises one or more of the following thermally cleavable groups: -CONH-, - COO-, -CONHSO2-, -PO3-, -SO2-, -COCH2NHCO-, or -COS-, and BLOCK is directly linked to R-NH- through one of the thermally cleavable groups.