Interference 103,482
a metallocene catalyst comprising:
a) a metallocene compound; and
b) an ionizing agent;
wherein the metallocene compound comprises the general
formula:
R”(CpR )(CpR’ )MHal
n m 2
where Cp is cyclopentadienyl or a substituted
cyclopentadienyl, each R and R’ is a hydrocarbyl radical
having from 1-20 carbon atoms and is the same or
different
and is selected such that CpR’ is a sterically different
m
ring from CpR resulting in a lack of bi-lateral symmetry
n
for the compound, R” is a structural bridge imparting
stereorigidity to the compound, M is a Group 3, Group 4,
Group 5 or Group 6 metal, n is from 0 to 4, m is from 0
to 4 and Hal is a halogen and wherein the ionizing agent
converts a neutral metallocene compound to a metallocene
cation which operates as a catalyst to produce
(1) hemiisotactic olefin polymers or (2) syndio-isoblock
polymer having molecular chains in which syndiotactic and
isotactic sequences are present and the sequence length
is 3 to 50 monomer units;
or
a process, for the preparation of (1) a syndio-isoblock
polymer having molecular chains in which syndiotactic and
isotactic sequences are present and the sequence length
is
3 to 50 monomer units or (2) hemiisotactic olefin
polymers,
comprising polymerization of propylene or a 1-olefin of
the formula RCH=CHR’ in which R and R’ are identical or
different and are hydrogen or an alkyl radical having 1
to 14 carbon atoms or R and R’ combine with the carbon
atoms joining them together to for[sic, form] a ring at a
temperature of -60 to 100 C, a pressure of 0.5 to 100 bar,O
in solution, in suspension or in the gas phase, in the
presence of a catalyst composed of a metallocene and an
aluminoxane, wherein the metallocene is a . . . [compound
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Last modified: November 3, 2007