If desired, the COCs may contain from 0 to 99% by weight, based on the total weight of the COC, of polymerized units of an acyclic olefin of the formula VIII: R9, R10, R11 and R12 here are identical or different and are a hydrogen atom or a C1-C10-hydrocarbon radical, e.g. a C1-C8-alkyl radical or a C6-C14-aryl radical.