US Patent 10160245 Heat-sensitive recording material

The invention relates to a heat-sensitive recording material. A heat-sensitive recording material, comprising a carrier substrate and a heat-sensitive, color-forming layer that contains at least one color former and at least one phenol-free color developer, is characterized in that said at least one color developer is a compound of formula (I) where Ar1 and Ar2 are a phenyl group and/or a C1-C4-alkyl substituted phenyl group. The invention also relates to a method for producing this heat-sensitive recording material and to the use, in a heat-sensitive recording material, of the color developer of formula (I) that is present in said heat-sensitive, color-forming layer.