Note: Descriptions are shown in the official language in which they were submitted.
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MODIFIED ALUMOXANE CATALYST ACTIVATOR
The present invention relates to compounds that are useful as catalyst
activator components. More particularly the present invention relates to such
compounds that are particularly adapted for use in the polymerization of
unsaturated
compounds having improved activation efficiency and performance. Such
compounds are particularly advantageous for use in a polymerization process
wherein catalyst, catalyst activator, and at least one polymerizable monomer
are
combined under polymerization conditions to form a polymeric product.
It is previously known in the art to activate Ziegler-Natta polymerization
catalysts, particularly such catalysts comprising Group 3-10 metal complexes
containing defocalized ~-bonded ligand groups, by the use of an activator.
Generally
in the absence of such an activator compound, also referred to as a
cocatalyst, little
or no polymerization activity is observed. A class of suitable activators are
aluminoxanes, or alkylaluminoxanes, which are generally believed to be
oligomeric or
polymeric alkylaluminoxy compounds, including cyclic oligomers. The skilled
artisan
will appreciate that the precise chemical structure of individual alumoxane
molecules
including methyl alumoxane has eluded full characterization. The structure of
methylalumoxane is postulated to consist of linear chains, cyclic rings, or
polyhedra,
which forms may interconvert in solution. Generally such compounds contain, on
average about 1.5 alkyl groups per aluminum atom, and are prepared by reaction
of
trialkylaluminum compounds or mixtures of compounds with water (Reddy et al,
Prog.
Poly. Sci., 1995, 20, 309-367). The resulting product is in fact a mixture of
various
substituted aluminum compounds including especially, trialklyaluminum
compounds.
The amount of such free trialkylaluminum compound in the mixture generally
varies
from 1 to 50 percent by weight of the total product. Examples of alumoxanes
include
methylalumoxane (MAO) made by hydrolysis of trimethylaluminum as well as
modified methylalumoxane (MMAO), made by hydrolysis of a mixture of
trimethylaluminum and triisobutylaluminum. MMAO advantageously is more soluble
in aliphatic solvents than is MAO.
A different type of activator compound is a Bronsted acid salt capable of
transferring a proton to form a cationic derivative or other catalytically
active
derivative of such Group 3-10 metal complex. Preferred Bronsted acid salts are
such
compounds containing a ration/ anion pair that is capable of rendering the
Group 3-
10 metal complex catalytically active. Suitable activators comprise
fluorinated
arylborate anions, most preferably, the tetrakis(pentafluorophenyl)borate
anion.
Additional suitable anions include sterically shielded diboron anions of the
formula:
t349~.A ~ CA 02302173 2000-02-29
< < "" ,
~, " , " <,
« ~ , , . , ,
. < < < ,
' ' f < < < . , ~ '", ~.'
< < , , ,
, ,
«, ., ": "~,
ArF2B ' /BA~z
CS2
wherein:
S is hydrogen, alkyl, fluoroalkyl, aryl, or fluoroaryl, ArF is fluoroaryl, and
X' is either
hydrogen or halide, disclosed in US-A-5,447,895.
Examples of preferred charge separated (catioN anion pair) activators are
protonated
ammonium, sulfonium, or phosphonium salts capable of transferring a hydrogen
ion,
disclosed in US-A-5,198,401, US-A-5,132,380, US-A-5,470,927, and US-A-
5,153,157, as well
as oxidizing salts such as carbonium, ferrocenium and silyilium salts,
disclosed in USP's
5,350,723, 5,189,192 and 5,626,087.
Further suitable activators for the above metal complexes include strong Lewis
acids
including (trisperfluorophenyl)borane and tris(perfluorobiphenyl)borane. The
former
composition has been previously disclosed for the above stated end use in EP-A-
520,732,
and elsewhere, whereas the latter composition is disclosed in Marks, et al.,
J_. Am. Chem.
Soc., 118, 12451-12452 (1996). Additional teachings of the foregoing
activators may be
found in Chen, ei~ al, J. Am. Chef. Soc. 1997, 119, 2582-2583, Jia et al,
Oraanometallics,
1997, 16, 842-857. and Coles et al, J. Am. Chem. Soci 1997, 119, 8126-8126.
All of the
foregoing salt and Lewis acid activators in practice are based on
perfluorophenyl substituted
boron compounds. Although the quantity of such activator compound used is
quite low,
residual boron and fluorinated benzene values remaining in the polymer may be
detrimental
to final polymer properties, such as applications requiring high dielectrical
properties.
In USP 5,453,410, an alumoxane, particularly methylalumoxane, was disclosed
for
use in combination with cationic constrained geometry metal complexes,
especially in a molar
ratio of metal complex to alumoxane of from 1/1 to 1/50. This combination
beneficially
resulted in improved polymerization efficiency. Similarly, in US-A-5,527,929,
US-A-5,616,664, US-A-5,470,993, US-A-5,556,928, US-A-5,624,878, various
combinations of
metal complexes with trispentafluorophenyl boron cocatalyst, and optionally an
alumoxane,
were disclosed for use as catalyst compositions for olefin polymerization.
In EP-A-719,797, the use of two or more catalyst activators, specifically one
or more
aluminum compounds, such as aluminum trialkyls or alumoxanes, together with a
boron
compound, such as trispentafluorophenylborane were disclosed. The resulting
polymer
products were distinctly bimodal, thereby indicating that the catalyst
activators did not interact
to form a single, highly active activator differing from either of the
in'ttial reagents.
Despite the satisfactory pertormance of the foregoing catalyst activators
under a
variety of polymerization conditions, there is still a need for improved
-2-
AI~.N~E~ SHEE'
CA 02302173 2000-02-29
VltO 99/15534 - PCT/US98/19314
cocatalysts for use in the activation of various metal complexes under a
variety of
reaction conditions. In particular, it is desirable to remove boron containing
contaminating compounds from such activator composition. Such boron containing
contaminating compounds result primarily from ligand exchange with the
alumoxane,
and comprise trialkylboron compounds having from 1 to 4 carbons in each alkyl
group, for example, trimethylboron, triisobutylboron, or mixed trialkylboron
products.
It would be desirable if there were provided compounds that could be employed
in
solution, slurry, gas phase or high pressure polymerizations and under
homogeneous
or heterogeneous process conditions having improved activation properties,
that lack
such trialkylboron species.
It is known that an exchange reaction between aluminum trialkyl compounds
and tris(perfluorophenyl)borane occurs under certain conditions. This
phenomenon
has been previously described in US-A-5,602,269.
According to the present invention there is now provided a composition of
matter comprising:
a fluorohydrocarbyl- substituted alumoxane compound corresponding to the
formula:
R1-(AIR30)m-R2,
wherein:
R1 independently each occurrence is a C1_4p aliphatic or aromatic group;
R2 independently each occurrence is a C1-40 aliphatic or aromatic group or in
the case of a cyclic oligomer, R1 and R2 together form a covalent bond;
R3 independently each occurrence is a monovalent, fluorinated organic group
containing from 1 to 100 carbon atoms or R1, with the proviso that in at least
one
occurrence per molecule, R3 is a monovaient, fluorinated organic group
containing
from 1 to 100 carbon atoms, and
m is a number from 1 to 1000.
The composition may exist in the form of mixtures of compounds of the
foregoing formula, and further mixtures with a trihydrocarbylaluminum
compound,
and may exist in the form of linear chains, cyclic rings, or polyhedra, which
forms may
interconvert in solution.
Additionally according to the present invention there is provided a catalyst
composition for polymerization of an ethylenically unsaturated, polymerizable
monomer comprising, in combination, the above described combination and a
Group
3-10 metal complex, or the reaction product resulting from such combination.
Even further according to the present invention there is provided a process
for
polymerization of one or more addition polymerizable monomers comprising
-3-
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contacting the same, optionally in the presence of an inert aliphatic,
alicyclic or
aromatic hydrocarbon, with the above catalyst composition or a supported
derivative
thereof.
Finally, there is provided a composition comprising the reaction product of an
alkylalumoxane and BAr~3; wherein:
Are is a fluorinated aromatic moiety of from 6 to 30 carbon atoms; -
the reaction steps comprising contacting the alkylalumoxane and BArf3 under
ligand exchange conditions and removing at least a portion of the volatile
byproducts.
The foregoing combination is uniquely adapted for use in activation of a
variety of metal complexes, especially Group 4 metal complexes, under standard
and
atypical olefin polymerization conditions. In particular, it is highly
desirable for use in
polymerization processes in combination with Group 4 metal complexes
containing
one or two cyclopentadienyl groups (including substituted, multiple ring and
partially
hydrogenated derivatives thereof) and an inert support to prepare supported
catalysts
for use in the polymerization of olefins, particularly under gas phase
polymerization
conditions.
All references herein to elements belonging to a certain Group refer to the
Periodic Table of the Elements published and copyrighted by CRC Press, Inc.,
1995.
Also any reference to the Group or Groups shall be to the Group or Groups as
reflected in this Periodic Table of the Elements using the IUPAC system for
numbering groups.
The catalyst activators of the invention are readily prepared by combining an
alkylalumoxane, which may also contain residual quantities of trialkylaluminum
compound, with a fluoroaryl ligand source, preferably a strong Lewis acid
containing
fluoroaryl ligands, optionally followed by removing byproducts formed by the
ligand
exchange. The reaction may be performed in a solvent or diluent, or neat, and
preferably is performed neat, or in as concentrated solution as possible, for
as long
reaction time as possible. Intimate contacting of the neat reactants can be
effectively
achieved by removing volatile components under reduced pressure from a
solution of
the separate reactants, to form a solid mixture of reactants and, optionally,
intermediate exchange products and desired final exchange products, and
thereafter,
continuing such contacting optionally at an elevated temperature. Preferred
fluoroaryl ligand sources are trifluoroarylboron compounds, most preferably
tris(pentafluorophenyl)boron, which result in trialkylboron ligand exchange
products,
that are relatively volatile and easily removable from the reaction mixture,
or more
preferably, trifluoroarylaluminum compounds. It should be noted that the
standard
technique of preparation of alkylalumoxanes, for example reaction of a
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V1~0 99/15534 - PCT/US98/19314
trialkylaluminum compound with water, cannot directly be adapted for use to
form the
present compositions under industrial conditions, due to thermal instability
and
reactivity, that is, explosive nature, of trifluoroarylaluminum compounds,
especially,
tris(pentafluoro)phenylaluminum.
~ The reactants may be combined in any aliphatic; alicyclic or aromatic liquid
diluent or mixture thereof. Preferred are Cg_g aliphatic and alicyclic
hydrocarbons and
mixtures thereof, including hexane, heptane, cyclohexane, and mixed fractions
such
as Isopar''"s E, available from Exxon Chemicals Inc. Preferably however, the
reactants
are combined in the absence of a diluent, that is, the neat reactants are
merely
combined and heated. Preferred contacting times are at least one hour,
preferably at
least 90 minutes, at a temperature of at least 25 °C, preferably at
least 30 °C, most
preferably at least 35°C. Desirably, the contacting is also done prior
to addition of a
metal complex catalyst, such as a metallocene, in order to avoid formation of
further
derivatives and multiple metal exchange products having reduced catalytic
effectiveness. After contacting of the alkylalumoxane and source of fluoroaryl
ligand
the reaction mixture may be purified to remove ligand exchange products,
especially
any trialkylboron compounds by any suitable technique. Alternatively, but less
desirably, a Group 3-10 metal complex catalyst may first be combined with the
reaction mixture prior to removing the residual ligand exchange products. It
will be
appreciated by the skilled artisan that the degree of fluoroaryl-substitution
of the
alumoxane can be controlled over a wide range by manipulating the reaction
conditions. Thus, a low degree of fluoroaryl substitution can be achieved by
the use
of lower temperatures, solvents, and shorter contact times. Conversely, a
higher
degree of substitution can be achieved by the use of neat reactants, Tong
reaction
times, higher temperatures and dynamic removal of volatile byproducts under
vacuum. By selecting appropriate reaction conditions, fluoroaryl-substituted
alumoxanes having a wide range of properties can be produced which may be
tailored
to a variety of uses.
Suitable techniques for removing alkyl exchange byproducts from the reaction
mixture include degassing optionally at reduced pressures, distillation,
solvent
exchange, solvent extraction, extraction with a volatile agent, contacting
with a zeolite
or molecular sieve, and combinations of the foregoing techniques, all of which
are
conducted according to conventional procedures. The quantity and nature of the
residual boron-containing exchange byproducts remaining in of the resulting
product
may be determined by "B NMR analysis. Preferably the quantity of residual
trialkylboron exchange product is less than 10 weight percent, more preferably
less
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Vl0 99/15534 PCT/US98/19314
than 1.0 weight percent, most preferably less than 0.1 weight percent, based
on
fluorohydrocarbyl- substituted alumoxane compound.
As previously mentioned the resulting product contains a quantity of
fluorinated organic substituted aluminoxy compound. More particularly, the
product
may be defined as a composition comprising a mixture of aluminum containing
Lewis
acids said mixture corresponding to the formula:
[(-AIQ'-O-)Z (-AIAr'-O-)Z~l(Ar'Z~AI2Q's-r)
where;
Q' independently each occurrence is selected from C,_~ alkyl;
Arf is a fluorinated aromatic hydrocarbyl moiety of from 6 to 30 carbon atoms;
z is a number from 1 to 50, preferably from 1.5 to 40, more preferably from 2
to 30, and the moiety (-AIQ'-O-) is a cyclic or linear oligomer with a repeat
unit of 2-
30;
z' is a number from 1 to 50, preferably from 1.5 to 40, more preferably from 2
to 30, and the moiety (-AIAr~-O-) is a cyclic or linear oligomer with a repeat
unit of 2-
30; and
z" is a number from 0 to 6, and the moiety (ArfYAI2Q'~Z-) is either
tri(fluoroarylaluminum), trialkylaluminum, or an adduct of
tri(fluoroarylaluminum) with
a sub-stoichiometric to super-stoichiometric amount of a trialkylaluminum.
The moieties (Ar~~Al2Q'&~) may exist as discrete entities or dynamic exchange
products. That is, such moieties may be in the form of dimeric or other
multiple
centered products in combination with metal complexes resulting from partial
or
complete ligand exchange, especially when combined with other compounds such
as
metallocenes. Such exchange products may be fluxional in nature, the
concentration
thereof being dependant on time, temperature, solution concentration and the
presence of other species able to stabilize the compounds, th;~;r~by
preventing or
slowing further ligand exchange. Preferably z" ~S from 1-5, more preferably
from 1-3.
Preferred compositions acc~r ;,g to the present invention are those wherein
Arf is pentafluorophenvl, a .u Q' is C~.~ alkyl. Most preferred compositions
according
3(~ tn tn6 ~; ~~nt invention are those wherein Ar is pentafluorophenyl, and O'
each
occurrence is methyl, isopropyl or isobutyl.
The present composition is a highly active co-catalyst for use in activation
of
metal complexes, especially Group 4 metallocenes for the polymerization of
olefins.
In such use it is desirably employed as a dilute concentration in a
hydrocarbon liquid,
especially an aliphatic hydrocarbon liquid for use as a homogeneous catalyst
activator, especially for solution polymerizations. Additionally, the
composition may
be deposited on an inert support, especially a particulated metal oxide or
polymer, in
-6-
r
CA 02302173 2000-02-29
1310 99/15534 PCT/US98/19314
combination with the metal complex to be activated according to known
techniques
for producing supported olefin polymerization catalysts, and thereafter used
for gas
phase or slurry polymerizations.
When in use as a catalyst activator, the molar ratio of metal complex to
activator composition is preferably from 0.1:1 to 3:1, more preferably from
0.2:1 to
2:1, most preferably from 0.25:1 to 1:1, based on the metal contents of each
component. In most polymerization reactions the molar ratio of metal complex:
polymerizable compound employed is from 10-12:1 to 10'1:1, more preferably
from
10'12:1 to 10'5:1.
The reagents employed in the preparation and use of the present
compositions, particularly the alumoxane reagent and, where used, the support,
should be thoroughly dried prior to use, preferably by heating at 200-500
°C,
optionally under reduced pressure, for a time from 10 minutes to 100 hours. By
this
procedure the quantity of residual aluminum trialkyl present in the alumoxane
is
reduced as far as possible.
The support for the activator component may be any inert, particulate
material, but most suitably is a metal oxide or mixture of metal oxides,
preferably
alumina, silica, an aluminosilicate or clay material. Suitable volume average
particle
sizes of the support are from 1 to 1000 wM, preferably from 10 to 100 ~M. Most
desired supports are calcined silica, which may be treated prior to use to
reduce
surface hydroxyl groups thereon, by reaction with a silane, a
trialkylaluminum, or
similar reactive compound. Any suitable means for incorporating the present
composition onto the surface of a support (including the interstices thereof)
may be
used; including dispersing the cocatalyst in a liquid and contacting the same
with the
support by slurrying, impregnation, spraying, or coating and thereafter
removing the
liquid, or by combining the cocatalyst and a support material in dry or paste
form and
intimately contacting the mixture, thereafter forming a dried, particulated
product. In
a preferred embodiment, silica is preferably reacted with a tri(C,-
,oalkyl)aluminum,
most preferably, trimethylaluminum, triethylaluminum, triisopropylaluminum or
triisobutylaluminum, in an amount from 0.1 to 100, more preferably 0.2 to 10
mmole
aluminum/ g silica, and thereafter contacted with the above activator
composition, or
a solution thereof, in a quantity sufficient to provide a supported cocatalyst
containing
from 0.1 to 1000, preferably from 1 to 500 mole activator/ g silica. The
active
catalyst composition is prepared by thereafter adding the metal complex or a
mixture
of metal complexes to be activated to the surface of the support.
Suitable metal complexes for use in combination with the foregoing
cocatalysts include any complex of a metal of Groups 3-10 of the Periodic
Table of
CA 02302173 2000-02-29
WO 99/15534 PCT/US98/19314
the Elements capable of being activated to polymerize monomers, especially
olefins
by the present activators. Examples include Group 10 diimine derivatives
corresponding to the formula:
CT-CT
N ~'M* X'zA- wherein N is Ar*-N ~N-Ar*
N ~
M* is Ni(II) or Pd(II);
X' is halo, hydrocarbyl, or hydrocarbyloxy;
Ar* is an aryl group, especially 2,6-diisopropylphenyl or aniline group;
CT-CT is 1,2-ethanediyl, 2,3-butanediyl, or form a fused ring system wherein
the two T groups together are a 1,8-naphthanediyl group; and
A- is the anionic component of the foregoing charge separated activators.
Similar complexes to the foregoing are also disclosed by M. Brookhart, et al.,
in J. Am. Chem. Soc., 118, 267-268 (1996) and J. Am. Chem. Sod, 117, 6414 -
6415
(1995), as being active polymerization catalysts especially for polymerization
of a-
olefins, either alone or in combination with polar comonomers such as vinyl
chloride,
alkyl acrylates and alkyl methacrylates.
Additional complexes include derivatives of Group 3, 4, or Lanthanide metals
containing from 1 to 3 ~-bonded anionic or neutral ligand groups, which may be
cyclic
or non-cyclic delocalized n-bonded anionic ligand groups. Exemplary of such ~-
bonded anionic ligand groups are conjugated or nonconjugated, cyclic or non-
cyclic
dienyl groups, allyl groups, boratabenzene groups, and arene groups. By the
term "n
-bonded" is meant that the ligand group is bonded to the transition metal by a
sharing
of eiactrons from a partially de!~!~~!:ze~ ;~-4ond.
Each atom in the delocalized ~-bonded group may ir;dspendently be
substituted with a radical selected from the group consisting of hydrogen,
halogen,
hydrocarbyl, halohydrocarbyl, hydrocarbyi-substituted metalloid radicals
wherein the
metalloid is selected from Group 14 of the Periodic Table of the Elements, and
such
hydrocarbyl- or hydrocarbyl-substituted metalloid radicals further substituted
with a
Group 15 or 16 hetero atom containing moiety. Included within the term
"hydrocarbyl" are C1_20 straight, branched and cyclic alkyl radicals, Cg_20
aromatic
radicals, C7_20 alkyl-substituted aromatic radicals, and C7_20 aryl-
substituted alkyl
radicals. fn addition two or more such radicals may together form a fused ring
system, including partially or fully hydrogenated fused ring systems, or they
may form
a metallocycle with the metal. Suitable hydrocarbyl-substituted
organometalloid
radicals include mono-, di- and tri-substituted organometalloid radicals of
Group i 4
elements wherein each of the hydrocarbyl groups contains from 1 to 20 carbon
_g_
CA 02302173 2000-02-29
V1~0 99/15534 PCT/US98/19314
atoms. Examples of suitable hydrocarbyl-substituted organometalloid radicals
include trimethylsilyl, triethylsilyl, ethyldimethylsilyl, methyldiethylsilyl,
triphenylgermyl,
and trimethylgermyl groups. Examples of Group 15 or 16 hetero atom containing
moieties include amine, phosphine, ether or thioether moieties or divalent
derivatives
thereof, e. g. amide, phosphide, ether or thioether groups bonded to the
transition
metal or Lanthanide metal, and bonded to the hydracarbyl group or to the
hydrocarbyl- substituted metalloid containing group.
Examples of suitable anionic, delocalized ~-bonded groups include
cyclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorenyl,
octahydrofluorenyl, pentadienyl, cyclohexadienyl, dihydroanthracenyl,
hexahydroanthracenyl, decahydroanthracenyl groups, and boratabenzene groups,
as
well as C,_,o hydrocarbyl-substituted or C~_,o hydrocarbyl-substituted silyl
substituted
derivatives thereof. Preferred anionic delocalized n-bonded groups are
cyclopentadienyl, pentamethylcyclopentadienyl, tetramethylcyclopentadienyl,
tetramethylsilylcyclo-pentadienyl, indenyl, 2,3-dimethylindenyl, fluorenyl, 2-
methylindenyl, 2-methyl-4-phenylindenyl, tetrahydrofluorenyl,
octahydrofluorenyl, and
tetrahydroindenyl.
The boratabenzenes are anionic ligands which are boron containing
analogues to benzene. They are previously known in the art having been
described
by G. Herberich, et al., in Organometallics, 1995, 14, 1, 471-480. Preferred
boratabenzenes correspond to the formula:
R' R"
R"
R R"
wherein R" is selected from the group consisting of hydrocarbyl, silyl, or
germyl, said R" having up to 20 non-hydrogen atoms. In complexes involving
divalent
derivatives of such delocalized ~-bonded groups one atom thereof is bonded by
means of a covalent bond or a covalently bonded divalent group to another atom
of
the complex thereby forming a bridged system.
Suitable metal complexes for use in the catalysts of the present invention may
be derivatives of any transition metal including Lanthanides, but preferably
of Group
3, 4, or Lanthanide metals which are in the +2, +3, or +4 formal oxidation
state
meeting the previously mentioned requirements. Preferred compounds include
metal
complexes (metallocenes) containing from 1 to 3 n-bonded anionic ligand
groups,
which may be cyclic or noncyclic delocalized ~-bonded anionic ligand groups.
Exemplary of such ~-bonded anionic ligand groups are conjugated or
nonconjugated,
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CA 02302173 2000-02-29
CVO 99/15534 PCT/US98/19314
cyclic or non-cyclic dienyl groups, allyl groups, and arena groups. By the
term "~-
bonded° is meant that the ligand group is bonded to the transition
metal by means of
delocalized electrons present in a ~ bond.
Each atom in the delocalized n-bonded group may independently be
5 substituted with a radical selected from the group consisting of halogen,
hydrocarbyl,
halohydrocarbyl, and hydrocarbyl-substituted metalloid radicals wherein the
metalloid
is selected from Group 14 of the Periodic Table of the Elements. Included
within the
term "hydrocarbyl" are C1 _2p straight, branched and cyclic alkyl radicals, Cg-
20
aromatic radicals, C~_20 alkyl-substituted aromatic radicals, and C~-20 aryl-
10 substituted alkyl radicals. In addition two or more such radicals may
together form a
fused ring system or a hydrogenated fused ring system. Suitable hydrocarbyl-
substituted organometalloid radicals include mono-, di- and trisubstituted
organometalloid radicals of Group 14 elements wherein each of the hydrocarbyl
groups contains from 1 to 20 carbon atoms. Examples of suitable hydrocarbyl-
15 substituted organometalloid radicals include trimethylsilyl, triethylsilyl,
ethyldimethylsilyl, methyldiethylsilyl, triphenylgermyl, and trimethylgermyl
groups.
Examples of suitable anionic, delocalized ~-bonded groups include
cyclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorenyl,
octahydrofluorenyl, pentadienyl, cyclohexadienyl, dihydroanthracenyl,
20 hexahydroanthracenyl, and decahydroanthracenyl groups, as well as C1 _10
hydrocarbyl-substituted derivatives thereof. Preferred anionic delocalized ~-
bonded
groups are cyclopentadienyl, pentamethylcyclopentadienyl, tetramethylcyclo-
pentadienyl, indenyl, 2,3-dimethylindenyl, fluorenyl, 2-methylindenyl and 2-
methyl-4-
phenylindenyl.
25 More preferred are metal complexes corresponding to the formula:
LIMXmX'nX"p, or a dimer thereof
wherein:
L is an anionic, delocalized, n-bonded group that is bound to M, containing up
to 50 nonhydrogen atoms, optionally two L groups may be joined together
through
30 one or more substituents thereby forming a bridged structure, and further
optionally
one L may be bound to X through one or more substituents of L;
M is a metal of Group 4 of the Periodic Table of the Elements in the +2, +3 or
+4 formal oxidation state;
X is an optional, divalent substituent of up to 50 non-hydrogen atoms that
35 together with L forms a metallocycle with M;
X' is an optional neutral Lewis base having up to 20 non-hydrogen atoms;
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WO 99/15534 ~ PCT/US98/19314
X" each occurrence is a monovalent, anionic moiety having up to 40 non-
hydrogen atoms, optionally, two X" groups may be covalently bound together
forming
a divalent dianionic moiety having both valences bound to M, or form a
neutral,
conjugated or nonconjugated diene that is ~c-bonded to M (whereupon M is in
the +2
oxidation state), or further optionally one or more X" and one or more X'
groups may
be bonded together thereby forming a moiety that is both covalently bound to M
and
coordinated thereto by means of Lewis base functionality;
I is 1 or 2;
mis0orl;
n is a number from 0 to 3;
p is an integer from 0 to 3; and
the sum, I+m+p, is equal to the formal oxidation state of M.
Such preferred complexes include those containing either one or two L
groups. The latter complexes include those containing a bridging group linking
the
two L groups. Preferred bodging groups are those corresponding to the formula
(ER*2)x wherein E is silicon or carbon, R* independently each occurrence is
hydrogen or a group selected from silyl, hydrocarbyl, hydrocarbyloxy and
combinations thereof, said R* having up to 30 carbon or silicon atoms, and x
is 1 to 8.
Preferably, R* independently each occurrence is methyl, benzyl, tert-butyl or
phenyl.
Examples of the foregoing bis(L) containing complexes are compounds
corresponding to the formula:
R3 A3 R3 R3
R3
(I) (ll)
z (R*
z
R3
or
wherein:
M is titanium, zirconium or hafnium, preferably zirconium or hafnium, in the
+2
or +4 formal oxidation state;
R3 in each occurrence independently is selected from the group consisting of
hydrogen, hydrocarbyl, silyl, germyl, cyano, halo and combinations thereof,
said R3
having up to 20 non-hydrogen atoms, or adjacent R3 groups together form a
divalent
derivative (that is, a hydrocarbadiyl, siladiyl or germadiyl group) thereby
forming a
fused ring system, and
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V1C0 99/15534 PCT/US98/19314
X" independently each occurrence is an anionic ligand group of up to 40
nonhydrogen atoms, or two X" groups together form a divalent anionic ligand
group
of up to 40 nonhydrogen atoms or together are a conjugated diene having from 4
to
30 non-hydrogen atoms forming a ~c-complex with M, whereupon M is in the +2
formal
oxidation state, and
R*, E and x are as previously defined.
The foregoing metal complexes are especially suited for the preparation of
po(iymers having stereoregular molecular structure. In such capacity it is
preferred
that the complex possess C2 symmetry or possess a chiral, stereorigid
structure.
Examples of the first type are compounds possessing different delocalized n-
bonded
systems, such as one cyclopentadienyl group and one fluorenyl group. Similar
systems based on Ti(IV) or Zr(IV) were disclosed for preparation of
syndiotactic olefin
polymers in Ewen, et al., J. Am. Chem. Soc. 110, 6255-6256 (1980): Examples of
chiral structures include bis-indenyl complexes. Similar systems based on
Ti(IV) or
Zr(IV) were disclosed for preparation of isotactic olefin polymers in Wild et
al., J.
Oryanomet. Chem, 232, 233-47, (1982).
Exemplary bridged ligands containing two n-bonded groups are: (dimethylsilyl-
bis-cyclopentadienyl), (dimethylsilyl-bis-methylcyclopentadienyl),
(dimethylsilyl-bis-
ethylcyclopentadienyl, (dimethylsilyl-bis-t-butylcyclopentadienyl),
(dimethylsilyl-bis-
tetramethylcyclopentadienyl), (dimethylsilyl-bis-indenyl), (dimethylsilyl-bis-
tetrahydroindenyl), (dimethylsilyl-bis-fluorenyl), (dimethylsilyl-bis-
tetrahydrofluurenyl),
(dimethylsilyl-bis-2-methyl-4-phenylindenyi), (dimethylsilyl-bis-2-
methylindenyl),
(dimethylsilyl-cyclopentadienyl-fluorenyl), (1, 1, 2, 2-tetramethyl-1, 2-
disilyl-bis-
cyclopentadienyl), (1, 2-bis(cyclopentadienyl)ethane, and (isc~~;~pylidene-
cyclopentadienyl-fluorenyl).
Preferred X° groups ark g~;a~iea from hydride, hydrocarbyl, silyl,
germyl,
halohydrocarbvl, "diosilyl, silylhydrocarbyl and aminohydrocarbyf groups, or
two X"
groups together form a divalent derivative of a conjugated diene or else
together they
form a neutral, ~c-bonded, conjugated diene. Most preferred X" groups are C1-
20
hydrocarbyl groups.
A further class of metal complexes utilized in the present invention
correspond
to the formula:
wherein:
LIMX~.y~X'nX°p, or a dimer thereof
L is an anionic, delocalized, x-bonded group that is bound to M, containing up
to 50 nonhydrogen atoms;
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CA 02302173 2000-02-29
WO 99115534 PCT/US98/19314
M is a metal of Group 4 of the Periodic Table of the Elements in the +2, +3 or
+4 formal oxidation state;
X is a divalent substituent of up to 50 non-hydrogen atoms that together with
L
forms a metallocycle with M;
X' is an optional neutral Lewis base ligand having up to 20 non-hydrogen
atoms;
X" each occurrence is a monovalent, anionic moiety having up to 20 non-
hydrogen atoms, optionally two X" groups together may form a divalent anionic
moiety having both valences bound to M or a neutral C5_30 conjugated diene,
and
further optionally X' and X" may be bonded together thereby forming a moiety
that is
both covalently bound to M and coordinated thereto by means of Lewis base
functionality;
I is 1 or 2;
misl;
n is a number from 0 to 3;
p is an integer from 1 to 2; and
the sum, I+m+p, is equal to the formal oxidation state of M.
Preferred divalent X substituents preferably include groups containing up to
30 nonhydrogen atoms comprising at least one atom that is oxygen, sulfur,
boron or
a member of Group 14 of the Periodic Table of the Elements directly attached
to the
delocalized ~-bonded group, and a different atom, selected from the group
consisting
of nitrogen, phosphorus, oxygen or sulfur that is covalently bonded to M.
A preferred class of such Group 4 metal coordination complexes used
according to the present invention correspond to the formula:
R3
R3 Z-Y
M X"2
R3 R3
wherein:
M is titanium or zirconium in the +2 or +4 formal oxidation state;
R3 in each occurrence independently is selected from the group consisting of
hydrogen, hydrocarbyl, silyl, germyl, cyano, halo and combinations thereof,
said R3
having up to 20 non-hydrogen atoms, or adjacent R3 groups together form a
divalent
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CA 02302173 2000-02-29
VYO 99/15534 - PCTNS98/19314
derivative (that is, a hydrocarbadiyl, siladiyi or germadiyl group) thereby
forming a
fused ring system,
each X" is a halo, hydrocarbyl, hydrocarbyloxy or silyl group, said group
having up to 20 nonhydrogen atoms, or two X" groups together form a C5_30
conjugated diene;
Y is -O-, -S-, -NR*-, -PR*-; and
Z is SiR*2, CR*2, SiR*2SiR*2, CR*2CR*2, CR*=CR*, CR*2SiR*2, or GeR*2,
wherein: R* is as previously defined.
Illustrative Group 4 metal complexes that may be employed in the practice of
the present invention include:
cyclopentadienyltitaniumtrimethyl,
cyclopentadienyltitaniumtriethyl,
cyclopentadienyltitaniumtriisopropyl,
cyclopentadienyltitaniumtriphenyl,
cyclopentadienyltitaniumtribenzyl,
cyclopentadienyltitanium-2,4-pentadienyl,
cyclopentadienyltitaniumdimethylmethoxide,
cyclopentadienyltitaniumdimethylchloride,
pentamethylcyclopentadienyltitaniumtrimethyl,
indenyltitaniumtrimethyl,
indenyltitaniumtriethyl,
indenyltitaniumtripropyl,
indenyltitaniumtriphenyl,
tetrahydroindenyltitaniumtribenryl,
pentamethylcyclopentadienyltitaniumtriisopropyl,
pentamethylcyclopentadienyltitaniumtribenryl,
pentamethylcyclopentadienyltitaniumdimethylmethoxide,
pentamethylcyclopentadienyltitaniumdimethylchloride,
(r!5-2,4-dimethyl-1,3-pentadienyl)titaniumtrimethyl,
octahydrofluorenyltitaniumtrimethyl,
tetrahydroindenyltitaniumtrimethyl,
tetrahydrofluorenyltitaniumtrimethyl,
(1,1-dimethyl-2,3,4,9,10-~-1,4,5,6,7,8-
hexahydronaphthalenyl)titaniumtrimethyl,
(1,1,2,3-tetramethyl-2,3,4,9,10-r!-1,4,5,6,7,t3-
hexahydronaphthalenyl)titaniumtrimethyl,
(tart-butylamido)(tetramethyl-r!5-cyclopentadienyl) dimethylsilanetitanium
dichloride,
(tert-butylamido)(tetramethyl-r!5-cyclopentadienyl)dimethylsilanetitanium
dimethyl,
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VI(O 99/15534 ~ PCTNS98/19314
(tart-butylamido)(tetramethyl-rl5-cyclopentadienyl)-1,2-ethanediyltitanium
dimethyl,
(tart-butylamido)(hexamethyl-rl5-indenyl)dimethylsilanetitanium dimethyl,
(tart-butylamido)(tetramethyl-rl5-cyclopentadienyl)dimethylsilane titanium
(III) 2-
(dimethylamino)benzyl;
(tart-butylamido)(tetramethyl-rl5-cyctopentadienyl)dimethylsilanetitanium
(III) allyl,
(tart-butylamido)(tetramethyl-~~-cyclopentadienyl)dimethylsilanetitanium (II)
1,4
Biphenyl-1,3-butadiene,
(tart-butylamido)(2-methylindenyl)dimethylsilanetitanium (II) i,4-Biphenyl-1,3-
butadiene,
(tart-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV) 1,3-butadiene,
(tart-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (II) 1,4
Biphenyl-1,3-butadiene,
(tart-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium {IV) 1,3-
butadiene,
(tart-butylamido)(2,3-dimethylindenyl)dimethylstlanetitanium (II) 1,3-
pentadiene,
(tart-butylamido)(2-methylindenyl)dimethylsilanetitanium (II) 1,3-pentadiene;
(tart-butylamido)(2-methylindenyl)dimethylsilanetitanium (lV) dimethyl,
(tart-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium (II) 1,4-
diphenyl-
1,3-butadiene,
(tart-butylamido)(tetramethyl-rt5-cyctopentadienyl)dimethylsilanetitantum (IV)
1,3-
butadiene,
(tart-butylamido)(tetramethyl-rl5-cyclopentadienyl)dimethylsilanetitanium (II)
1,4-
dibenzyl-1,3-butadiene,
(tart-butylamido)(tetramethyl-rl5-cyclopentadienyl}dimethylsilanetitanium (II)
2,4-
hexadiene,
(tart-butylamido)(tetramethyl-~b-cyclopentadienyl)dimethylsilanetitanium (II)
3-methyl
1,3-pentadiene,
(tart-butylamido)(2,4-dimethyl-1,3-pentadien-2-
yl)dimethylsilanetitaniumdimethyl,
(tart-butylamido)(1,1-dimethyl-2,3,4,9,10-rl-1,4,5,6,7,8-hexahydronaphthalen-4-
yl)dimethylsilanetitaniumdimethyl,
(tart-butylamido)(1,1,2,3-tetramethyl-2,3,4,9,10-rl-1,4,5,6,7,8-
hexahydronaphthalen-
4-yl)dimethylsilanetitaniumdimethyl,
(tent-butylamido)(tetramethylcycfopentadienyl)dimethylsilanetitanium 1,3-
pentadiene,
(tart-butylamido)(3-(N-pyrrolidinyl)inden-1-yl)dimethylsilanetitanium 1,3-
pentadiene,
(tart-butylamido)(2-methyl-s-indacen-1-yl)dimethylsilanetitanium 1,3-
pentadiene, and
(tent-butylamido)(3,4-cyctopenta(~phenanthren-2-yl)dimethylsilanetitanium 1,4-
Biphenyl-1,3-butadiene.
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WO 99/15534 PCT/US98/19314
Bis(L) containing complexes including bridged complexes suitable for use in
the present invention include:
biscyclopentadienylzirconiumdimethyl,
biscyclopentadienyltitaniumdiethyl,
biscyclopentadienyltitaniumdiisopropyl,
biscyclopentadienyltitaniumdiphenyl,
biscyclopentadienylzirconium dibenzyl,
biscyclopentadienyltitanium-2,4-pentadienyl,
biscyclopentadienyltitaniummethylmethoxide,
biscyclopentadienyltitaniummethylchloride,
bispentamethylcyclopentadienyltitaniumdimethyl,
bisindenyltitaniumdimethyl,
indenylfluorenyltitaniumdiethyl,
bisindenyltitaniummethyl(2-(dimethylamino)benzyl),
bisindenyltitanium methyltrimethylsilyl,
bistetrahydroindenyltitanium methyltrimethylsilyl,
bispentamethylcyclopentadienyftitaniumdiisopropyl,
bispentamethylcyclopentadienyititaniumdibenzyl,
bispentamethylcyclopentadienyltitaniummethylmethoxide,
bispentamethylcyclopentadienyltitaniummethylchloride,
(dimethylsilyl-bis-cyclopentadienyl)zirconiumdimethyl,
(dimethylsilyl-bis-pentamethylcyclopentadienyl)titanium-2,4-pentadienyl,
(dimethylsilyf-bis-t-butylcyclopentadienyl)zirconiumdichloride,
(methylene-bis-pentamethylcyclopentadienyl)titanium(III) 2-
(dimethylamino)benzyl,
(dimethylsilyl-bis-indenyl)zirconiumdichloride,
(dimethylsilyl-bis-2-methylindenyl)zirconiumdimethyl,
(dimethylsilyl-bis-2-methyl-4-phenylindenyl)zirconiumdimethyl,
(dimethylsilyl-bis-2-methylindenyl)zirconium-1,4-Biphenyl-1,3-butadiene,
(dimethylsilyl-bis-2-methy!-4-phenylindenyl)zirconium (II) 1,4-Biphenyl-1,3-
butadiene,
(dimethylsilyl-bis-tetrahydroindenyl)zirconium(II) 1,4-Biphenyl-1,3-butadiene,
(dimethylsilyl-bis-fluorenyl)zirconiumdichloride,
(dimethylsilyl-bis-tetrahydrofluorenyl)zirconiumdi(trimethylsilyl),
(isopropylidene)(cyclopentadienyl)(fluorenyl)zirconiumdibenzyl, and
(dimethylsilylpentamethylcyclopentadienylfluorenyl)zirconiumdimethyl.
Suitable polymerizable monomers include ethylenically unsaturated
monomers, acetylenic compounds, conjugated or non-conjugated dienes, and
polyenes. Preferred monomers include olefins, for examples alpha-olefins
having
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V1C0 99/15534 ~ PCT/US98/19314
from 2 to 20,000, preferably from 2 to 20, more preferably from 2 to 8 carbon
atoms
and combinations of two or more of such alpha-olefins. Particularly suitable
alpha-
olefins include, for example, ethylene, propylene, 1-butane, 1-pentane, 4-
methylpentene-1, 1-hexane, 1-heptene, 1-octane, 1-nonene, 1-decene, 1-
undecene,
1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, or combinations
thereof, as
well as long chain vinyl terminated oligomeric or polymeric reaction products
formed
during the polymerization, and C,~ a-olefins specifically added to the
reaction
mixture in order to produce relatively long chain branches in the resulting
polymers.
Preferably, the alpha-olefins are ethylene, propane, 1-butane, 4-methyl-
pentane-1, 1-
hexane, 1-octane, and combinations of ethylene and/or propane with one or more
of
such other alpha-olefins. Other preferred monomers include styrene, halo- or
alkyl
substituted styrenes, tetrafluoroethylene, vinylcyclobutene, 1,4-hexadiene,
dicyciopentadiene, ethyfidene norbornene, and 1,7-octadiene. Mixtures of the
above-
mentioned monomers may also be employed.
In general, the polymerization may be accomplished at conditions well known
in the prior art for Ziegler-Natta or Kaminsky-Sinn type polymerization
reactions.
Examples of such well known polymerization processes are depicted in WO
88/02009, U.S. Patent Nos. 5,084,534, 5,405,922, 4,588,790, 5,032,652,
4,543,399,
4,564,647, 4,522,987, and elsewhere. Preferred polymerization temperatures are
from 0-250°C. Preferred polymerization pressures are from atmospheric
to 3000
atmospheres.
Molecular weight control agents can be used in combination with the present
cocatalysts. Examples of such molecular weight control agents include
hydrogen,
silanes or other known chain transfer agents. A particular benefit of the use
of the
present cocatalysts is the ability (depending on reaction conditions) to
produce
narrow molecular weight distribution a-olefin homopolymers and copolymers in
greatly improved cocatalyst efficiencies and purity, especially with respect
to residual
aluminum containing contaminants. Preferred polymers have Mw/Mn of less than
2.5, more preferably less than 2.3. Such narrow molecular weight distribution
polymer products are highly desirable due to improved tensile strength
properties.
Gas phase processes for the polymerization of C2.~ olefins, especially the
homopolymerization and copolymerization of ethylene and propylene, and the
copolymerization of ethylene with C~ a-olefins such as, for example, 1-butane,
1-
hexene, 4-methyl-1-pentane are well known in the art. Such processes are used
commercially on a large scale for the manufacture of high density polyethylene
(HDPE), medium density polyethylene (MDPE), linear low density polyethylene
(LLDPE) and polypropylene.
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VKO 99/15534 - PCT/US98/19314
The gas phase process employed can be, for example, of the type which
employs a mechanically stirred bed or a gas fluidized bed as the
polymerization
reaction zone. Preferred is the process wherein the polymerization reaction is
carried
out in a vertical cylindrical polymerization reactor containing a fluidized
bed of
polymer particles supported above a perforated plate, the fluidization grid,
by a flow
of fluidization gas.
The gas employed to fluidize the bed comprises the monomer or monomers
to be polymerized, and also serves as a heat exchange medium to remove the
heat
of reaction from the bed. The hot gases emerge from the top of the reactor,
normally
via a tranquilization zone, also known as a velocity reduction zone, having a
wider
diameter than the fluidized bed and wherein fine particles entrained in the
gas stream
have an opportunity to gravitate back into the bed. It can also be
advantageous to
use a cyclone to remove ultra-fine particles from the hot gas stream. The gas
is then
normally recycled to the bed by means of a blower or compressor and a one or
more
heat exchangers to strip the gas of the heat of polymerization.
A preferred method of cooling of the bed, in addition to the cooling provided
by the cooled recycle gas, is to feed a volatile liquid to the bed to provide
an
evaporative cooling effect. The volatile liquid employed in this case can be,
for
example, a volatile inert liquid, for example, a saturated hydrocarbon having
3 to 8,
preferably 4 to 6, carbon atoms. In the case that the monomer or comonomer
itself
is a volatile liquid, or can be condensed to provide such a liquid this can be
suitably
be fed to the bed to provide an evaporative cooling effect. Examples of olefin
monomers which can be employed in this manner are olefins containing from 3 to
eight, preferably from 3 to six carbon atoms. The volatile liquid evaporates
in the hot
fluidized bed to form gas which mixes with the fluidizing gas. If the volatile
liquid is a
monomer or comonomer, it will undergo some polymerization in the bed. The
evaporated liquid then emerges from the reactor as part of the hot recycle
gas, and
enters the compressioNheat exchange part of the recycle loop. The recycle gas
is
cooled in the heat exchanger and, if the temperature to which the gas is
cooled is
below the dew point, liquid will precipitate from the gas. This liquid is
desirably
recycled continuously to the fluidized bed. It is possible to recycle the
precipitated
liquid to the bed as liquid droplets carried in the recycle gas stream, as
described, for
example, in EP-A-89691, US-A-4543399, WO 94/25495 and US-A-5352749, which
are hereby incorporated by reference. A particularly preferred method of
recycling
the liquid to the bed is to separate the liquid from the recycle gas stream
and to
reinject this liquid directly into the bed, preferably using a method which
generates
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CA 02302173 2000-02-29
VltO 99!15534 PCT/US98/19314
fine droplets of the liquid within the bed. This type of process is described
in WO
94/28032, the teachings of which are also hereby incorporated by reference.
The polymerization reaction occurring in the gas fluidized bed is catalyzed by
the continuous or semi-continuous addition of catalyst. The catalyst can also
be
subjected to a prepolymerization step, for example, by polymerizing a small
quantity
of olefin monomer in a liquid inert diluent, to provide a catalyst composite
comprising
catalyst particles embedded in olefin polymer particles.
The polymer is produced directly in the fluidized bed by catalyzed
(co)polymerization of the monomers) on the fluidized particles of catalyst,
supported
catalyst or prepolymer within the bed. Start-up of the polymerization reaction
is
achieved using a bed of preformed polymer particles; which, preferably, is
similar to
the target polyolefin, and conditioning the bed by drying with inert gas or
nitrogen
prior to introducing the catalyst, the monomers) and any other gases which it
is
desired to have in the recycle gas stream, such as a diluent gas, hydrogen
chain
transfer agent, or an inert condensable gas when operating in gas phase
condensing
mode. The produced polymer is discharged continuously or discontinuously from
the
fluidized bed as desired, optionally exposed to a catalyst kill and optionally
palletized.
Similarly, supported catalysts for use in slurry polymerization may be
prepared
and used according to previously known techniques. Generally such catalysts
are
prepared by the same techniques as are employed for making supported catalysts
used in gas phase polymerizations. Slurry polymerization conditions generally
encompass polymerization of a C2_2o olefin, diolefin, cycloolefin, or mixture
thereof in
an aliphatic solvent at a temperature below that at which the polymer is
readily
soluble in the presence of a supported catalyst.
It is understood that the present invention is operable in the absence of any
component which has not been specifically disclosed. The following examples
are
provided in order to further illustrate the invention and are not to be
construed as
limiting. Unless stated to the contrary, all parts and percentages are
expressed on a
weight basis. Where stated the term "room temperature" refers to a temperature
from 20 to 25 °C, the term "overnight" refers to a time from 12 to 18
hours, and the
term "mixed alkanes° refers to the aliphatic solvent, Isopar ~ E,
available from Exxon
Chemicals Inc.
EXAMPLES
Tris(perfluorophenyl)borane (FAB) was obtained as a solid from Boulder
Scientific Inc. and used without further purification. Modified methalumoxane
(MMAO-3A) in heptane was purchased from Akzo-Nobel. MAO and
-19-
3492A. _' CA 02302173 2000-02-29
..,.
.. .~ r; ' . " .~ ..
, i r ~ ' ~ . , , , ,
~, ~ ~ ' . .
r s
r . , , ~ . . . ,
' ~ ,
' t a r , . r . . ' . < r , ,
trimethylaluminum (TMA) both in toluene were purchased from Aldrich Chemical
Co.
Tris(perfluorophenyl)aluminum (FAAL) in toluene was prepared by exchange
reaction between tris(perfluorophenyl)borane and trimethylaluminurn. All
solvents
were purified using the technique disclosed by Pangbom et al, Organometallics,
1996, i5, 1518-1520. All compounds and solutions were handled under an inert
atmosphere (dry box).
Example 1
Preparation of pentafluorophenyl-exchanged alumoxane
A solution of tris(pentafluorophenyl) borane (0.015 M in mixed alkanes
(Isopar ~ E), 5 mL) was combined with a solution of MMAO-3A (diluted to 0.05M
with
mixed alkanes, 5 mL). The resulting solution was stirred, then the solvent was
removed under vacuum. The neat residue was allowed to stand at 25°C for
approximately 2 hours. The residue was then dissolved in 5 mL of toluene to
give a
solution of pentafluorophenyl-exchanged alumoxane. Elemental analysis of the
solution showed it to contain 1000 ppm AI, 3600 ppm F, and 31 pprn B. This
analysis indicates that the molar ratio of F/AI = 5.1, and that 83 mole
percent of the
boron was removed from the mixture as volatile trialkylborane compounds.
Example 2
Preparation of pentafluorophenyl-exchanged alumoxane
Example 1 was repeated, except that the residue remaining after
devolatilization and aging was dissolved in mixed alkanes (Isopar ~ E).
Polymerizations
A.1 gallon computer-controlled stirred autoclave was charged with
approxirnatefy 1450 g of mixed alkanes solvent (Isopar ~ E), and about 125 g
of 1-
octene. 10 mmoles Of H2 was added as a molecular weight control agent. The
mixture was stirred and heated to 130 degrees C. The solution was saturated
with
ethylene at 450 psig (3.4 MPa). Catalyst/ co-catalyst solutions were prepared
by
combining solutions of [(tetramethylcyclopentadienyl) dimethylsilyl-N-tert-
butylamido]
titanium (II) (1,3-pentadiene) (0.005 M in mixed alkanes), and either a
combination of
tris(pentafluorophenyl) borane (0.015M in mixed alkanes) and MMAO-3A (0.5 M in
mixed alkanes) without solvent devolatilization or aging (comparative); MMAO-
3A
alone (comparative); or pentafluorophenyl-exchanged alumoxane from Examples 1
or 2 (invention). The catalyst solution was added to the reactor via a pump.
The
reactor temperature was controlled by controlling the temperature of the
reactor
-20-
AAIi~N~7ED SHEE'~
CA 02302173 2000-02-29
WO 99/15534 PCT/US98/19314
minutes polymerization time, the resulting solution was removed from the
reactor
into a nitrogen-purged collection vessel. After cooling, the vessel was
removed to the
air and 10 mL of a solution of a phosphorous containing antioxidant and a
hindered
phenol stabilizer was added. The stabilizer solution was prepared by combining
6.67
5 g of IRGAPHOST"" 168 (available from Ciba-Geigy Corp.) and 3.33 g of
IRGANOXT""
1010 (available from Ciba-Geigy Corp.) with 500 mL of toluene: The polymer was
recovered by removal of the solvent under reduced pressure in a vacuum oven
for 2
days. The reaction conditions are shown in Table 1 below. The polymer
characterization results are shown in Table 2.
Table 1
Run Cat. mL Cat.mL cocat.umole polymer efficiency
Ti
soln soln. soln.* (g) Kg poly./m
Ti
1 (comp)A 0.5 ** 2.5 168 1.4
2 B 0.5 0.5 2.5 51 0.4
3 B 0.5 1.0 2.5 209 1.7
4 C 0.5 0.5 2.5 55 0.4
5 C 0.5 1.0 2.5 204 1.7
6 C 0.25 0.5 1.25 124 2.1
7 (comp)A 0.5 ** 2.5 181 1.5
8 (comp)D 0.5 1.07 2.5 0 0
9 com E 0.5 2.14 2.5 0 0
* based on AI content
** sufficient cocatalyst solution is added to produce a final AI/Ti molar
ratio of 10
Catalyst soln. A was prepared by adding 0.5 mL of 0.05M MMAO-3A to 13 mL of
mixed
alkanes. To this was added 0.5 mL of O.Ot M tris(pentafluorophenyl) borane,
followed by
0.5 mL of 0.005 M [(tetramethylcyclopentadienyl) dimethylsilyl-N-tent-
butytamido] titanium
(II) (1,3-pentadiene).
Catalyst soln. B was prepared by combining the indicated amounts of
pentafluorophenyl-
exchanged alumoxane from Example 1 with 13 mL of mixed alkanes, followed by
the
addition of a 0.005 M solution of [(tetramethylcyclopentadienyl) dimethylsilyl-
N-tert-
butylamido] titanium (II) (1,3-pentadiene).
Catalyst soln. C was prepared by combining the indicated amounts of
pentafluorophenyl-
exchanged alumoxane from Example 2 with 13 mL of mixed alkanes, followed by
the
addition of a 0.005 M solution of [(tetramethylcyclopentadienyl) dimethylsilyl-
N-tert-
butylamido] titanium (II) (1,3-pentadiene).
Catalyst soln. D was prepared by combining 1.07 mL of 0.05M MMAO-3A to 13 mL
of mixed
alkanes. To this was added 0.5 mL of 0.005 M [(tetramethylcyclopentadienyl)
dimethylsilyl-
N-tart-butylamido] titanium (II) (1,3-pentadiene).
Catalyst soln. E was prepared by combining 2.14 mL of 0.05M MMAO-3A to 13 mL
of mixed
alkanes. To this was added 0.5 mL of 0.005 M [(tetramethylcyclopentadienyl)
dimethylsilyl-
N-tart-butylamido] titanium (II) (1,3-pentadiene).
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Table 2
Run AI:Ti* 12** 110/12 121/12
1 (comp) 10 6.07 6.05 -
2 6.4 0.81 5.71 16.22
3 12.8 1.67 5.90 16.86
4 6.4 0.88 6.07 15.60
12.8 2.23 5.92 15.71
6 12.8 1.28 5.82 15.68
7(comp) 10 4.50 6.03 16.97
8(comp) 6.4 - - _
9 com 12.8 - - -
* molar ratio based on metal
** ASTM
The above data in Table 1 and 2 indicate that the inventive compound
5 produces higher molecular weight polymer than that produced by simply mixing
B(CeF5)3 with MMAO-3A, as indicated by the lower values for 12 (Runs 2-6
compared
to 1 and 7). In addition, the pentafluorophenyl-modified alumoxane catalyst
system
with a 12.8 AI:Ti ratio showed higher efficiency than the simple mixture of
B(CgFS)3
with MMAO-3A (Runs 3,5,6 compared to 1 and 7). Finally, the composition of the
invention could be usefully employed at AI:Ti ratios between 6.4 and 12.8,
whereas
MMAO-3A was completely inactive at these low ratios (comparative runs 8 and
9).
Example 3
3.01 g of silica supported methylalumoxane (Witco 02794/HU04) was slurried
in 25 mL toluene. To this slurry was added 0.511 g [B(CgF5)3) as a dry solid.
The
mixture was agitated for 3 days. At this time, the solids were collected on a
fritted
funnel, washed three times with 15 mL portions of toluene and once with 20 mL
pentane, and dried in vacuo. A 2.00 g portion of the modified supported
material was
slurried in 18 mL pentane, and 1.0 mL of a 0.1 M solution of
(tetramethylcyclopenta-
dienyl)dimethylsilyl(N-tart-butylamido) titanium (II) (1,3-pentadiene) in
pentane was
added. After 5 minutes, the solids were collected on a fritted funnel, washed
twice
with 10 mL pentane, and dried in vacuo to yield the supported catalyst product
as a
pale green solid.
Polymerization
The polymerization conditions of Example 2 were substantially repeated using
a 0.1 g sample of the above supported catalyst to prepare approximately 200 g
of
ethylene/octene copolymer at a catalyst efficiency of 3.1 Kg polymer/gTi). A
comparative polymerization using the same metal complex and Witco 02794/HU04
supported MAO (without treatment with [B(CgFS)3]) under identical conditions
showed
a catalyst efficiency of 1.5 Kg polymer/gTi).
CA 02302173 2000-02-29
VSO 99/15534 PCT/US98/19314
Gas Phase Polymerization
Continuous gas phase polymerization is carried out in a 6 liter gas phase
reactor having a two inch diameter 12 inch long fluidization zone and an eight
inch
diameter eight inch long velocity reduction zone connected by a transition
section
having tapered walls. Typical operating conditions ranged from 40 to
100°C, 100 to
350 psig (0.7 to 2.4 MPa) total pressure and up to 8 hours reaction time.
Monomer,
comonomer, and other gases enter the bottom of the reactor where they pass
through a gas distributor plate. The flow of the gas is 2 to 8 times the
minimum
particle fluidization velocity [Fluidization Engineering, 2nd Ed., D. Kunii
and O.
Levenspiel, i 991, Butterworth-Heinemann]. Most of the suspended solids
disengag
in the velocity reduction zone. The gases exit the top of the velocity
reduction zone
and pass through a dust filter to remove any fines. The gases then pass
through a
gas booster pump. The polymer is allowed to accumulate in the reactor over the
course of the reaction. The total system pressure is kept constant during the
reaction
by regulating the flow of monomer into the reactor. Polymer is removed from
the
reactor to a recovery vessel by opening a series of valves located at the
bottom of the
fluidization zone thereby discharging the polymer to a recovery vessel kept at
a lower
pressure than the reactor. The pressures of monomer, comonomer and other gases
reported refer to partial pressures.
The catalyst prepared above, 0.05 g, is loaded into a catalyst injector in an
inert atmosphere glove box. The injector is removed from the glove box and
inserted
into the top of the reactor. The catalyst is added to the semi-batch gas phase
reactor
which is under an ethylene (monomer) pressure of 6.5 bar (0.65 MPa}, a 1-
butane
(comonomer) pressure of 0.14 bar (14 kPa), a hydrogen pressure of 0.04 bar (4
kPa)
and a nitrogen pressure of 2.8 bar (0.28 MPa). The temperature of
polymerization
throughout the run is 70°C. Polymer is conducted for 90 minutes. The
total system
pressure is kept constant during the reaction by regulating the flow of
monomer into
the reactor.
The yield of ethylene/ 1-butane copolymer powder is 43 g, corresponding to
an activity of 37 g/gHrBar (0.22 Kg/gHrMPa). A comparative polymerization
using the
same metal complex and Witco 02794/HU04 supported MAO (without treatment with
(B(CeF5)3]) {0.2 g} produces 16 g ethylene/hexene copolymer, corresponding to
an
activity of 6 g/gHrBar (0.06 Kg/gHrMPa).
Example 4
Tris{pentafluorophenyl)boron (5.775 gram, 11.3 mmol) was dissolved in
toluene (100 ml). A solution of MMAO-3A in heptane (11.6 ml of a 7.1 wt.
percent AI
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w0 99/15534 ~ PCT/US98/19314
solution) was added and the mixture agitated for 15 minutes. The volatile
components were removed under reduced pressure to give a pale yellow glass.
After
several hours at 25 °C, 200 ml of toluene was added to dissolve the
material and the
resulting solution was added to 2 g of silica (DavisonT"' 948, available from
Grace
Davison Company) that had been heated at 250°C for 3 hours in air. The
mixture
was agitated for 3 days. The slurry was filtered, and the resulting solid
washed with
50 ml toluene and dried under vacuum. Yield = 2.9 gram. [AIj = 8.2 wt.
percent.
1 gram of the treated support was slurrted in 10 ml hexane. 0.2 ml Of a 0.2 M
solution of {tetramethylcyclopentadienyl)dimethylsilyl(N-tart-
butylamido)titanium (It)
(1,3-pentadiene) in mixed alkanes was added and the mixture was agitated 30
minutes resulting in the formation of a green solid phase and a colorless
supernatant.
The slurry was filtered, washed with 30 ml hexane and dried under vacuum to
give
the solid, supported catalyst. A comparative catalyst was similarly prepared
using as
a support silica supported MMAO of comparable aluminum concentration as the
support used to prepare the above catalyst.
Polymerization
The gas phase polymerization conditions of Example 3 are substantially
repeated using as a catalyst the supported compositian prepared above. After
90
minutes of operation the yield of dry, free flowing powder is 64.7 gram which
corresponds to an activity of 96.7 g/gHrBar (0.97 Kg.gHrMPa).
The comparative catalyst gives an activity of 3.4 g/gHrBar (0.03 Kg/gHrMPa)
under identical polymerization conditions.
Example 5
In a glove box, the toluene adduct of trispentafluorophenylaluminum (FAAL)
(0.25 g, 0.403 mmol, prepared by the exchange reaction of
tris(pentafluoropnenyt)boron with trimethylaluminum (TMA) according to the
technique of US-A-5,602,269) was dissolved in 50 mL of dry toluene in a flask
and
solid MAO was added (0.47 g, heated to 80 °C under reduced pressure for
8 h to
remove TMA and volatile components, 8.06 mmol AI). The reaction mixture was
stirred for 4 h at room temperature and the solvent was removed under reduced
pressure. The residue was dried under reduced pressure for several hours to
afford
an off-white solid (83 percent yield). The corresponding NMR-scale reaction
using
the same ratio was carried out in a J-Young NMR tube with reagents being
loaded in
a glove box in toluene-db. As indicated by monitoring the reaction via NMR
studies,
the exchange reaction was essentially complete in 20 min at room temperature
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w0 99/15534 ~ PCT/US98/19314
(FAAL undetectable in the reaction mixture) and the products were found to be
a
mixture of two new species: the adduct of FAAL with a stoichiometric to sub-
stoichiometric amount of TMA, emperical formula: ((CsF5)tAl2(CH3)s.~.), where
z" is
about 1, and a mixture of pentafluorophenyl-substituted aluminoxy oligomers
and
methyl-substituted aluminoxy otigomers: [(MeAlO)Z ((CsF5)AIO)Z~]. The ratio,
z/z', was
about 6/1. The ratio of two products (aluminum compound/ aluminoxy compound)
was approximately 1.2/1. There were no noticeable spectral changes with longer
reaction times.
Spectroscopic data:
[(MeAlO)Z ((CsFS)AIO)Z~
The spectra exhibits very broad peaks for the AICgFS group resonating at a
typical AICeF5 region in'eF NMR. '9F NMR (C~DB, 23°C): S -123.09 (s,
br, 2 F, o-F), -
151.15 (s, br, 1 F, p-F), -160.19 (s, br, 2 F, m-F).
(CgF5)~AI2Me~.Z~
'H NMR (C~De, 23°C): 8 -0.29 (s, br, overlapping with MeAlO moiety).
'9F NMR (C,De, 23°C): b -121.94 (d, 3,lF-F = 15.3 Hz, 2 F, o-F), -
152.61 (s, br, 1 F, p-
F), -161.40 (s, br, 2 F, m-F).
Example 6
In a glove box, FAB (0.005 g, 0.01 mmol) and solid MAO (0.017 g, after
removal of toluene and free TMA under vacuum drying for 8 h, 0.20 mmol AI)
were
dissolved in 0.7 mL of toluene-afa at room temperature and loaded into a J-
Young
NMR .tube. NMR spectra were recorded after mixing these reagents in the NMR
tube
for 20 min. No FAB was detected in the reaction mixture and four new species
were
found to form from the alkyl/aryl B/AI exchange reaction:
BMe3,'H NMR (C,De, 23°C): 8 0.73 ppm
MeB(CBFS)2,'H NMR (C~De, 23°C): b 1.39ppm;'9F NMR (C~De,
23°C): b -
129.99 (d, 3,1F-F = 21.4 Hz, 2 F, o-F), -147.00 (t, 3JF.F = 18.3 Hz, 1 F, p-
F), -161.39 (tt,
3JF-F = 21.4 Hz, 2 F, m-F)
(CBF5)~.AI2Me~.r , (NMR data nearly the same as in example 5), and
[(MeAlO)Z ((CgF5)AIO)t] (NMR data nearly the same as in Example 5).
After 1.5 h of reaction at room temperature, BMe3 and MeB(CBFS)2 were non-
detectable by'9F NMR.
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VKO 99/15534 PCT/US98/19314
Example 7
In a glove box, FAB (0.15 g, 0.293 mmol) was dissolved in 50 mL of dry
toluene in a flask and solid MAO was added (1.70 g after removal of toluene
and free
TMA under vacuum drying for 8 h, 29.3 mmol AI). The reaction mixture was
stirred
for 2 h at room temperature and the solvent was removed under reduced
pressure.
The residue was dried in vacuum for a few hours to afford a white solid (85
percent
yield). The products were found to be a mixture of two species:
(CsFs)~.AI2Meg_Z~, with
nearly the same spectroscopic data as described in the example 5, as the minor
product, and [(MeAIO)Z ((CgF5)AIO)Z~], as the major product. Determination of
a more
definitive ratio of products could not be made due to overlapping'9F NMR
peaks.
Spectroscopic data for [(MeAlO)Z ((CsF5)AIO}Z~] are as follows:
'H NMR (CyDe, 23°C): 8 -0.24 (s, br, MeAlO moiety}
[(MeAlO)Z ((CgF5)AIO)Y exhibits very broad peaks (W~,2 > 600Hz) for AICeFS
group resonated at a typical AIC6F5region in the'9F NMR spectrum. '9F NMR
(C,De,
23°C): b -122.01 (s, br, 2 F, o-F), -151.72 (s, br, 1 F, p-F), -160.34
(s, br, 2 F, m-F).
x le
In a glove box, MMAO-3A (11.48 mL, 0.56 M in heptane, 6.42 mmol} was
loaded in a flask and the solvent was removed under reduced pressure, the
residue
was dried in vacuo overnight to afford a white solid. To this solid was added
a
mixture of solvents (20 mL of hexane and 5 mL of toluene} and FAB (0.077 g,
0.15
mmol). The reaction mixture was stirred for 4 h at room temperature and the
solvent
was removed under reduced pressure. The residue was dried under reduced
pressure for a few hours to afford a white solid (85 percent yield). The
products were
found to be a mixture of two species: [(Q3A10)Z ((C6F5)AIO}Z~] and
(CgFS)~.AI2Q3~.z"
(where Q3 is a mixture of methyl and isobutyl and z' is about 1 ) whose ratios
were
obscured by peak overlapping in'9F NMR.
Spectroscopic data:
[(Q3A10)Z ((CsFs}AIO)Z~
The spectra exhibits very broad peaks for the AICgF5 group resonating at a
typical
AICsF5 region in'9F NMR and generally as assigned in Example 7.
(CsFs}3AI'XAIR3
'H NMR (Ceps, 23°C): 8 -0.05 (s, br, (CgFs)3AI~x (trimethylaluminum},
0.15 (d), 0.99
(d}, and 1.84 (septet) for (CsFS)3AI~x (triisobutylaluminum).
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WO 99/15534 ~ PCT/US98/19314
'9F NMR (CBDg, 23°C): 8 -122.74 (d, 2 F, o-F), -152.18 (s, br, 1 F, p-
F), -161.09 (t, 2
F, m-F).
Polymerization
All feeds were passed through columns of alumina and a decontaminant
(Q-5T"" catalyst available from Englehardt Chemicals Inc.) prior to
introduction into the
reactor. Catalyst and cocatalysts are handled in a glovebox containing an -
atmosphere of argon or nitrogen. A stirred 2.0 liter reactor is charged with
about 740
g of mixed alkanes solvent and 118 g of 1-octene comonomer. Hydrogen is added
as a molecular weight control agent by differential pressure expansion from a
75 ml
addition tank at 25 psi (2070 kPa). The reactor is heated to the
polymerization
temperature of 130 °C and saturated with ethylene at 500 psig (3.4
MPa). Catalyst
((t-butylamido)(tetramethylcyclopentadienyl)dimethylsilanetitanium 1,3-
pentadiene)
and cocatalyst, as dilute solutions in toluene, were mixed and transferred to
a catalyst
addition tank and injected into the reactor. The polymerization conditions
were
maintained for 15 minutes with ethylene added on demand. The resulting
solution
was removed from the reactor, and 10 ml of a toluene solution containing
approximately 67 mg of a hindered phenol antioxidant (IrganoxT"' 1010 from
Ciba
Geigy Corporation) and 133 mg of a phosphorus stabilizer (IrgafosT"" 168 from
Ciba
Geigy Corporation) were then added. Polymers were recovered by drying in a
vacuum oven set at 140 °C for about 20 hours. Density values are
derived by
determining the polymer's mass when in air and when immersed in
methylethylketone. Micro melt index values (MMI) are obtained using a Custom
Scientific Instrument Inc. Model CS-127MF-015 apparatus at 190 °C, and
are unit-
less values calculated as follows: MMI =1/(0.00343 t - 0.00251 ), where t =
time in
seconds as measured by the instrument. Results are contained in Table 3.
Run Activatorcatalyst/ExothermYield Efficiency DensityMMI
activator*(C) (gy m Ti) ml
CE B(CBFS)31.5/ 3.5 32.2 0.45 0.901 3.8
1.5
CE B(CBF5)31.5/ 1.3 48.7 0.68 0.901 3.9
1.5
10 Ex. 2/ 40 1.5 6.2 0.065 0.902 0.4
7
11 " 21200 1.4 46.0 0.48 0.898 0.2
12 " 2/ 200 1.9 49.8 0.52 0.897 0.1
CE B C 2/ 2 3.4 81.8 0.85 0.898 5.3
F
CE: comparative example, not an example of the invention
* wmofe metal complex / wmole activator
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