residue of an aliphatic ring which optionally contains at least one hetero atom; E and J are each independently:(a) an alkyl group optionally containing (i) at least one hetero atom and/or (ii) at least one ##STR91## residue, in which R8 is alkyl, cycloalkyl or aryl; (b) a cycloalkyl group; (c) an aryl group; (d) a --K--L group in which L is a functional group and K is (i) a single bond; (ii) an a