Heat-sensitive recording material

Heat-sensitive recording material comprising a supporting substrate as well as a heat-sensitive color-forming layer containing at least one color former and at least one phenol-free color developer, wherein the at least one color developer is the compound of the formula (I)

• wherein m and n independently of one another are ≥1, Ar1 is an unsubstituted phenyl radical or a monosubstituted phenyl radical substituted with a C1-05-alkyl radical, an alkenyl radical, an alkinyl radical, a benzyl radical, an RO radical, a halogen radical, an ROC radical, an RO2C radical, a CN radical, an NO2 radical, an R—SO2O radical, an RO—SO2 radical, an R—NH—SO2 radical, an R—SO2NH radical, an R—NH—CO—NH radical, an R—SO2-NH—CO—NH radical, an R—NH—CO—NH—SO2 radical or an R—CO—NH radical, wherein R is a C1-05-alkyl radical, an alkenyl radical, an alkinyl radical, a phenyl radical, a tolyl radical or a benzyl radical, Ar2 is an unsubstituted phenyl radical or a monosubstituted phenyl radical or a phenyl radical substituted with a C1-C4 alkyl radical, and Y is at least one (m+n)-times substituted benzene or naphthalene group, wherein (m+n) is 2, 3 or 4 and wherein the compound of formula (1) is selected from N-phenyl-2-(3-(phenylsulfonyl)ureide)benzene sulfonamide;
• N-(4-tolyl)-2-(3-(phenylsulfonyl)ureide)benzene sulfonamide;
• N-(4-methoxyphenyl)-2-(3-(phenylsulfonyl)ureide)benzene sulfonamide;
• methyl 4-(2-(3-(phenylsulfonyl)ureide)phenyl sulfonamide) benzoate;
• N-(3-chlorophenyl)-2-(3-(phenylsulfonyl)ureide) benzene sulfonamide;
• 2-(3-(phenylsulfonyl)ureide)-N-(2-(3-phenylureido)phenyl)benzene sulfonamide;
• N-(2-tolyl)-2-(3-tosylureide)benzene sulfonamide;
• N-(4-tolyl)-2-(3-tosylureide)benzene sulfonamide;
• N-(3-tolyl)-2-(3-tosylureide)benzene sulfonamide;
• N-(4-methoxy-phenyl)-2-(3-tosylureide)benzene sulfonamide;
• methyl 4-(2-(3-tosylureide)phenyl sulfonamide) benzoate;
• N-(3-chlorphenyl)-2-(3-tosylureide)benzene sulfonamide;
• N-(4-chlorphenyl)-2-(3-tosylureide)benzene sulfonamide;
• 3-(2-(3-tosylureide)phenyl sulfonamide)phenyl 4-methyl benzene sulfonate;
• 4-methyl-N-((4-(N-(2-(3-phenylureide)phenyl) sulfamoyl)phenyl)carbamoyl)benzene sulfonamide;
• ethyl 4-(2-(3-tosylureide)phenyl) sulfonamide)benzoate;
• N-(2-(3-phenylureide)phenyl)-3-(3-tosylureide)benzene sulfonamide;
• N-phenyl-4-(3-tosylureide)benzene sulfonamide;
• N-(3-tolyl)-4-(3-tosylureide)benzene sulfonamide;
• methyl 4-(4-(3-tosylureide)phenyl sulfonamide)benzoate;
• N-(4-chlorphenyl)-4-(3-tosylureido)benzene sulfonamide;
• 4-methyl-N-((4-(N-(4-(3-phenylureide)phenyl)sulfamoyl)phenyl)carbamoyl)benzene sulfonamide;
• ethyl 4-(4-(3-tosylureide)phenyl sulfonamide)benzoate;
• N,N′-(((4-(N-phenyl sulfamoyl)-1,3-phenylene)bis(azanediyl))bis(carbonyl))bis(4-methyl benzene sulfonamide);
• N1,N3-diphenyl-4,6-bis(3-(phenyl sulfonyl)ureide)benzene-1,3-disulfonamide;
• N1,N3-diphenyl-4,6-bis(3-tosylureide)benzene-1,3-disulfonamide;
• diethyl 4-4′-((4,6-bis(3-tosylureide)-1,3-phenylene disulfonyl)bis(azanediyl))dibenzoate;
• and combinations thereof.