Heat sensitive recording material

摘要

A heat sensitive recording material comprises a heat sensitive color forming layer containing a color former of a colorless or light color leuco dyestuff, a developer which develops color by reaction with the color former upon heating and is a mixture of 97 to 70 weight % of 2,4'-dihydroxydiphenylsulfone and 3 to 30 weight % of 4,4'-dihydroxydiphenylsulfone and a sensitizer. The heat sensitive color forming layer is coated on a support. The heat sensitive recording material has excellent color forming property by which sufficiently high concentration and sensitivity of the color forming are obtained and has excellent stability of the image with time.