abstract |
Compounds having the formula: wherein R1 represents hydrogen, C1-C20 alkyl which is unsubstituted or substituted by one or more ammonium, mono-, di-, tri or tetra-C1-C12 alkylammonium groups or by one or more sulphonium groups or represents an aralkyl residue having a total of from 7 to 10 carbon atoms and, in which, the aryl group is unsubstituted or substituted by C1-C4alkyl, C1-C4 alkoxy or halogen and Z is a group selected from R2, R3 and R4, independently, representing hydrogen, C1-C4alkyl, C1-C4 alkoxy, halogen, NHCOC1-C4 alkyl or phenyl which is unsubstituted or substituted by. C1-C4 alkyl, C1-C4 alkoxy or halogen, a process for their preparation and use of the compounds of formula (1) as UV-absorbers which have improved absorption spectrum characteristics, superior resistance to exposure to UV light and excellent thermal stability, relative to known benzophenone compounds. |