| abstract |
This invention relates to supported metallocene catalyst compositions useful for addition reactions of prochiral alpha -olefins. Polymers, specifically propylene polymers, produced with this catalyst possess higher stereoregularities and consequently higher melting points compared to propylene polymers produced using previously known supported metallocene catalysts. The microstructure of the polymers obtained using the supported catalyst systems of this invention is similar to that obtained using analogous unsupported catalysts. The catalyst compositions comprise transition metal (i.e., metallocene) cations and beam comprising anionic activators in prescribed ratios on metal or metalloid oxide supports. The transition metal compound is represented by the formula: wherein M is selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten; R1 and R2 are identical or different, and are one of a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C6-C10 aryl group, a C6-C10 aryloxy group, a C2-C10 alkenyl group, a C2-C4 alkenyl group, a C7-C40 arylalkyl group, a C7-C40 alkylaryl group, a C8-C40 arylalkenyl group, or a halogen atom; R5 and R6 are identical or different, and are one of a halogen atom, a C1-C10 alkyl group which may be halogenated, a C6-C10 aryl group which may be halogenated, a C2-C10 alkenyl group, a C7-C40-arylalkyl group, a C7-C40 alkylaryl group, a C8-C40 arylalkenyl group, a -NR215, -SR15, -OR15, -OSiR315 or -PR215 radical, wherein R15 is one of a halogen atom, a C1-C10 alkyl group, or a C6-C10 aryl group; R7 is -B(R11)-, -Al(R11)-, -Ge-, -Sn, -O-, -S-, -SO-, -SO2-, -N(R11)-, -CO-, -P(R11)-, or -P(O)(R11)-; wherein: R11, R12 and R13 are identical or different and are a hydrogen atom, a halogen atom, a C1-C20 alkyl group, a C1-C20 fluoroalkyl group, a C6-C30 aryl group, a C6-C30 fluoroaryl group, a C1-C20 alkoxy group, a C2-C20 alkenyl group, a C7-C40 arylalkyl group, a C8-C40 arylalkenyl group, a C7-C40 alkylaryl group, or R11 and R12, or R11 and R13, together with the atoms binding them, can form ring systems; M2 is silicon, germanium or tin; R8 and R9 are identical or different and have the meanings stated for R11; m and n are identical or different and are zero, 1 or 2, m plus n being zero, 1 or 2; and the radicals R3, R4 and R10 are identical or different and have the meanings stated for R11, R12 and R13 and two adjacent R10 radicals can be joined together to form a ring system. |