Pressure sensitive recording materials

For a pressure-sensitive recording material comprising a unit containing a dye precursor or its solution and a unit containing a dye acceptor material, which is capable of color formation by reaction with the dye precursor, a sheet-like, dye acceptor material containing unit consisting of a carrier material which is in sheet or web form, coated on one side with the dye acceptor material, characterized in that the dye acceptor material is an intimate mixture comprising

• (a) either
• (aa) a 2-hydroxy-benzophenone of formula I ##STR17## where R.sub.1 is a hydroxy-group, an unsubstituted alkoxy residue with from 1 to 18 carbon atoms or an alkoxy residue with from 1 to 4 carbon atoms, carrying 1 or 2 hydroxy-groups, an alkoxy residue with from 1 to 4 carbon atoms, carrying 1 or 2 hydroxy groups and esterified with a saturated or olefinically unsaturated carboxylic acid with from 2 to 4 carbon atoms, R.sub.2 is hydrogen, a phenyl residue, the sulphonic acid group --SO.sub.3 H or the group --SO.sub.3 Me, Me being an alkali metal, R.sub.3 is hydrogen, the hydroxy group, an alkyl group with from 1 to 12 carbon atoms, an alkoxy group with from 1 to 18 carbon atoms or a phenyl residue, and R.sub.4 is hydrogen, the hydroxy group, a phenyl residue, the carboxy-group --COOH or the group --COOMe, Me being an alkali metal;
• or
• (bb) 3,5,7,3',4'-pentahydroxy-flavone of formula II ##STR18## and (b) a substituted benzotriazole of formula III ##STR19## where R.sub.1 is hydrogen or the tertiary butyl group, R.sub.2 an alkyl residue with from 1 to 12 carbon atoms, an alkoxy residue with from 1 to 12 carbon atoms, the cyclohexyl residue, the sulphonic acid group --SO.sub.3 H or the group --SO.sub.3 Me, Me being an alkali metal, and R.sub.3 is hydrogen or chlorine.