Patent ID: 6221983
Filing Date: 2001-04-24
Classification: C08F

Abstract:
A process for preparing copolymers of vinylaromatic and olefinic compounds having from 50 to 75% by weight of vinylaromatic compound, wherein the polymerization is carried out in dispersion in the presence of at least one metallocene catalyst system, and wherein styrene-diene two-block copolymers or styrene-diene three-block copolymers are used as dispersion aid, in which the diene block may be hydrogenated or unhydrogenated, and wherein the metallocene catalyst systems used are ones comprising as active constituentsA) metallocene complexes of the formula I ##STR9##where the substituents have the following meanings:M is titanium, zirconium, hafnium, vanadium, niobium or tantalum,X is fluorine, chlorine, bromine, iodine, hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, --OR.sup.6 or --NR.sup.6 R.sup.7,whereR.sup.6, R.sup.7 are C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl, alkylaryl, arylalkyl, fluoroalkyl or fluoroaryl each having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical,R.sup.1 to R.sup.5 are hydrogen, C.sub.1 -C.sub.10 -alkyl, 5- to 7-membered cycloalkyl which may in turn bear a C.sub.1 -C.sub.10 -alkyl group as substituent, C.sub.6 -C.sub.15 -aryl or arylalkyl, where two adjacent radicals may also together form a cyclic group having from 4 to 15 carbon atoms, or Si(R.sup.8).sub.3 whereR.sup.8 is C.sub.1 -C.sub.10 -alkyl, C.sub.3 -C.sub.10 -cycloalkyl or C.sub.6 -C.sub.15 -aryl,z is Xor the radicals R.sup.5 and Z together form a --R.sup.9 --A-- group, whereR.sup.9 is ##STR10##.dbd.BR.sup.10, .dbd.AlR.sup.10, --Ge--, --Sn--, --O--, --S--, .dbd.SO, .dbd.SO.sub.2, .dbd.NR.sup.10, .dbd.CO, .dbd.PR.sup.10 or .dbd.P(O)R.sup.10,whereR.sup.10, R.sup.11 and R.sup.12 are identical or different and are each a hydrogen atom, a halogen atom, a C.sub.1 -C.sub.10 -alkyl group, a C.sub.1 -C.sub.10 -fluoroalkyl 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.10 and R.sup.11 or R.sup.10 and R.sup.12, in each case together with the atoms connecting them, form a ring, andM.sup.1 is silicon, germanium or tin,A is --O--, --S--, ##STR11##whereR.sup.13 is C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl, C.sub.3 -C.sub.10 -cycloalkyl, alkylaryl, Si(R.sup.14).sub.3,.paren open-st.CH.sub.2.paren close-st..sub.n O--R.sup.14, .paren open-st.CH.sub.2 --CH.sub.2 --O.paren close-st..sub.n R.sup.14 or .paren open-st.CH.sub.2 --O.paren close-st..sub.n R.sup.14 whereR.sup.14 is hydrogen, C.sub.1 -C.sub.10 -alkyl C.sub.6 -C.sub.15 -aryl, which may in turn bear C.sub.1 -C.sub.4 -alkyl groups as substituents, or C.sub.3 -C.sub.10 -cycloalkyl andn is 1, 2 or 3 andB) a compound capable of forming metallocenium ions.