DEVELOPER, DISPERSIONS CONTAINING THE SAME, AND THERMAL RECORDING MATERIALS

摘要

2,4'-Dihydroxydiphenyl sulfone for developers which has a Hasen value of melt color of 300 to 2000; and a developer containing as the main component 2,4'-dihydroxydiphenyl sulfone having a content of trihydroxytriphenyl disulfone as impurity of 0.1 wt % or below. The developer can give thermal recording materials which have high sensitivity of color formation and are excellent in the shelf stability of developed images.