US Patent 7968494 Heat-sensitive recording material

A heat-sensitive recording material including: a substrate; a heat-sensitive color developing layer over the substrate, the heat-sensitive color developing layer composed mainly of a leuco dye and a color developer that develops color of the leuco dye upon heating; and a protective layer over the heat-sensitive color developing layer, the protective layer composed mainly of a water-soluble resin and a crosslinking agent, wherein the protective layer contains diacetone-modified polyvinyl alcohol as the water-soluble resin, and N-aminopolyacrylamide as the crosslinking agent.