The cycloolefin polymers (A) may comprise, in addition to the structural units that are derived from at least one monomer of the formulae I to VII, further structural units that are derived from at least one acyclic 1-olefin of the formula (VIII) ##STR6## where R9, R10, R11 and R12 are the same or different and are a hydrogen atom or a C1 -C8 -alkyl radical.