C5 -C12 cycloalkyl which is unsubstituted or mono-, di- or tri-substituted by C1 -C4 alkyl, C3 -C18 -alkenyl or a group of the formula (III), R5 is a direct bond, C1 -C12 -alkylene, cyclohexylene or phenylene, R7 is hydrogen, C1 -C8 alkyl or phenyl R8 is --CN or a group --COOR9 with R9 being as defined above, R10 and R11 which can be identical or different are as defined above for R14 and R15, an