rein one or more carbon atoms can be replaced by O, C???O, ???O(C???O)???, SiR2 and/or NR and wherein R is an aliphatic radical having 1 to 7 carbon atoms, wherein one or more carbon atoms can be replaced by O, C???O and/or ???O(C???O)???, and in which, for type B: Z denotes an aliphatic, cycloaliphatic or aromatic radical having 0 to 22 carbon atoms or a combination of these radicals, wherein one