Patent ID: 6927184

Claim:
A process for producing microfiber webs consisting essentially of a cycloolefin polymer by melt-blowing, wherein the cycloolefin polymer contains: (a) 0.1–100% by weight, based on the total mass of the cycloolefin polymer, of polymerized units derived from at least one polycyclic olefin of the formulae I, II, II′, III, IV, V or VI where R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 , which may be the same or different, are each a hydrogen atom, a C 1 –C 20 hydrocarbyl radical, or a cyclic or acyclic C 2 –C 20 alkenyl radical, or form a saturated, unsaturated or aromatic ring, subject to the proviso that the same R 1 to R 8 may have different meanings in the various formulae I to VI, and n is from 0 to 5, and (b) 0 to 99.9% by weight, based on the total mass of the cycloolefin polymer, of polymerized units derived from one or more acyclic olefins of the formula VII where R 9 , R 10 , R 11 and R 12 , which may be the same or different, are each a hydrogen atom or a linear, branched or saturated or unsaturated C 1 –C 20 hydrocarbyl radical, and (c) 0 to 45% by weight, based on the overall composition of the cycloolefin polymer, of polymerized units derived from one or more monocyclic olefins of the formula VIII where m is from 2 to 10.