Patent ID: 6214951
Filing Date: 2001-04-10
Classification: C08F,G02B

Abstract:
A process for the preparation of a copolymer of a cycloolefin copolymer (COC) having a low optical attenuation by copolymerization of 0.1 to 99.9% by weight, based on the total amount of the monomers, of at least one monomer of the formula I, II, III or IV ##STR16##in which R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are identical or different and are a hydrogen atom or a C.sub.1 -C.sub.8 -alkyl radical or a C.sub.6 -C.sub.16 -aryl radical, where identical radicals in the various formulae can have different meanings,from 0 to 99.9% by weight, based on the total amount of the monomers, of a cycloolefin of the formula V ##STR17##in which n is a number from 2 to 10, andfrom 0.1 to 99.9% by weight, based on the total amount of the monomers, of at least one acyclic 1-olefin of the formula VI ##STR18##in which R.sup.9, R.sup.10, R.sup.11 and R.sup.12 are identical or different and are a hydrogen atom or a C.sub.1 -C.sub.8 -alkyl radical or a C.sub.6 -C.sub.16 -aryl radical, in solution, in suspension, in a liquid cycloolefin monomer or cycloolefin monomer mixture or in the gas phase, at a temperature of from -78 to 150.degree. C., at a pressure of from 0.5 to 64 bar, in the presence of a catalyst comprising a metallocene as transition-metal component and an aluminoxane of the formula VII ##STR19##for the linear type and/or of the formula VIII ##STR20##for the cyclic type, where, in the formulae VII and VIII, R.sup.13 is a C.sub.1 -C.sub.6 -alkyl group or phenyl or benzyl, and n is an integer from 2 to 50, where the polymerization is carried out in the presence of a catalyst whose transition-metal component is at least one compound of the formula IX ##STR21##in whichM.sup.1 is titanium, zirconium, hafnium, vanadium, niobium or tantalum,R.sup.14 and R15 are identical or different and are a hydrogen atom, a halogen atom, a C.sub.1 -C.sub.10 -alkyl group, a C.sub.1 -C.sub.10 -alkoxy group, a C.sub.6 -C.sub.10 -aryl group, a C.sub.6 -C.sub.10 -aryloxy group, a C.sub.2 -C.sub.10 -alkenyl group, a C.sub.7 -C.sub.40 -arylalkyl group, a C.sub.7 -C.sub.40 -alkylaryl group or a C.sub.8 -C.sub.40 -arylalkenyl group, andm may be one or two, depending on the valency of the central atom M.sup.1,R.sub.18 is .dbd.BR.sup.19, .dbd.AIR.sup.19, --Ge--, --Sn--, --O--, --S--, .dbd.SO, .dbd.SO.sub.2, .dbd.NR.sup.19, .dbd.CO, .dbd.PR.sup.19 or .dbd.P(O)R.sup.19, where R.sup.19, R.sup.20 and R.sup.21 are identical or different and are a hydrogen atom, a halogen atom, a C.sub.1 -C.sub.10 -alkyl group, a C.sub.1 -C.sub.10 -fluoroalkyl ##STR22##group, a C.sub.6 -C.sub.10 -fluoroaryl group, a C.sub.6 -C.sub.10 -aryl group, a C.sub.1 -C.sub.10 -alkoxy group, a C.sub.2 -C.sub.10 -alkenyl group, a C.sub.7 -C.sub.40 -arylalkyl group, a C.sub.8 -C.sub.40 -arylalkenyl group or a C.sub.7 -C.sub.40 -alkylaryl group, or R.sup.19 and R.sup.20 or R.sup.19 and R.sup.21, in each case with the atoms connecting them, form a ring,M.sup.2 is silicon, germanium or tin,R.sup.16 and R.sup.17 are identical or different and are a monocyclic or polycyclic hydrocarbon radical which can form a sandwich structure with the central atom M.sup.1,wherein the metallocene of the formula IX has C.sub.2 -symmetry with respect to the ligands R.sup.16 and R.sup.17 and with respect to the central atom M.sup.1 connecting them in the case where R.sup.16 and R.sup.17 are identical and has C.sub.1 -symmetry in the case where R.sup.16 and R.sup.17 are different,wherein, when the copolymerization is complete, the copolymer is subjected to a purification process which results in an optimal attenuation of the material from 0.1 to 5 dB/m, andwherein, in a first step of the purification process, the reaction mixture is suspended with a filtration aid and a substance which precipitates the organometallic compounds in the reaction mixture, the heterogeneous components are filtered off in a second step, and, in a third step, the purified COC is precipitated from the COC filtrate with the aid of a precipitant or the solvent of the COC filtrate is evaporated off.