Antifoggants and Print Stabilizers for Photothermographic Systems Based on AgX/Ag Carboxylates

摘要

A unique feature of photothermographic (PTG) imaging systems, compared to conventional AgX materials, is that all of the components needed to form high-quality images are present in the film prior to imaging, and they are not removed from the film during or after processing. Caused by the inherent co-existence of these imaging chemistries within the film, a continuing challenge for PTG imaging systems is to prevent pre- and post-process image (fog) formation. Various blocking techniques used in protecting print stabilizers in photothermographic elements are possible and discussed below. In describing these techniques, the chemistry, advantages, and disadvantages of individual approaches are examined. In addition, a new blocking group for PTG applications is aryl sulfonyl compounds. It will be demonstrated that blocking of benzotriazole, a commonly used Ag~+ complexing agent, produces a print stabilizer with no premature release or adverse effect on PTG sensitometric parameters.