US Patent 7524621 Method of preparing silver carboxylate soaps

Silver salts of long chain carboxylic acids are prepared from long chain carboxylic acids by sequential addition of at least two different alkali metal hydroxides, one of which is lithium hydroxide, followed by converting the mixture of alkali metal carboxylates to silver carboxylates. Photothermographic materials prepared from such silver carboxylates display improved Dmin aging with little if any affect on other sensitometric properties.