| 摘要 |
<p>A catalyst system containing a magnesium siloxide support and a catalyst on the support exhibits high activity. The invention is further drawn to a catalyst system composition containing a halogenating agent and the catalyst system. The catalyst of the catalyst system is a mixture of two organometallic compounds. One of the organometallics is of the formula M(R)x, wherein M is titanium, vanadium, chromium or zirconium; x is 3 or 4; and each R is independently selected from halogen, a C1C20 alkyl, C1 to C20 alkoxide; or an amide. The second organometallic is a mono-, bi- or tricyclopentadienyl or substituted cyclopentadienyl metal compound represented by the general formula: (C5R1m)pR2s(C5R1m)M1Q3-p; and R2s(C5R1m)2M1Q1 wherein (C¿5R?1m) is a cyclopentadienyl or substituted cyclopentadienyl; each R1 is the same or different and is hydrogen or a hydrocarbyl radical such as alkyl, alkenyl, aryl, alkylaryl or arylalkyl radical containing from 1 to 20 carbon atoms or two carbon atoms are joined together to form a C¿4?-C6 ring; R?2¿ is a C¿1?-C4 alkylene radical, a dialkyl germanium or silicon or an alkyl phosphine or amine radical bridging two (C5R?1¿m) rings; Q is a hydrocarbyl radical such as aryl, alkyl, alkenyl, alkylaryl or arylalkyl radical having from 1-20 carbon atoms or halogen and can be the same or different; Q1 is an alkylidene radical having from 1 to about 20 carbon atoms; s is O or 1; p is O, 1 or 2; provided that when p is O, s is O; m is 4 when s is 1; m is 5 when s is O; at least one R1 is a hydrocarbyl radical when Q is an alkyl radical and M1 is a Group 4b, 5b or 6b metal.</p> |
