Note: Descriptions are shown in the official language in which they were submitted.
~ ATA 5463 -1- 2015549
-
SYNTHESIS OF ~lnYhALUMINOXANES
BACKGROUND OF THE Ihv~NllON
Field of the Invention
The present invention relates to the synthesis of
methylaluminoxanes which are useful as cocatalysts in the
homogeneous polymerization and copolymerization of olefins
and/or dienes in conjunction with metallocene compounds,
e.g., such Group IVB compounds as titanium, zirconium, and
hafnium.
Description of the Prior Art
Methylaluminoxane, prepared by carefully controlled
partial hydrolysis of trimethylaluminum, is useful as a
cocatalyst in conjunction with certain Group IVB compounds,
such as dicyclopentadienylzirconium dichloride and racemic
ethylenebis(indenyl) zirconium dichloride, in the
homogeneous polymerization of olefins. Such catalyst
systems, discovered by W. Kaminsky, are highly efficient and
have been the subject of much interest in recent patent and
journal literature, including the following: U.S. Patent
Nos. 4,404,344, 4,452,199, 4,544,762, and 4,665,208; J.
Poly. Sci.: Poly. Chem. Ed., Vol. 23, page 2117(1978);
Angew. Chem. Intl. Ed. Engl., Vol. 15, page 630(1976) and
Vol. 19, page 390(1980); Makromol. Chem., Rapid Commun.,
Vol. 4, page 417(1973) and Vol. 5, page 225(1984); and J. of
the Amer. Chem. Soc., Vol. 106, page 6355(1984). The known
schematic schemes for the synthesis of methylaluminoxane
typically show one or more of the following disadvantages:
long reaction times (with hydrated salts); low yields of the
" ,~
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methylaluminoxane (50% or lower); the potential for
explosions resulting from runaway reactions; low
temperatures (-10~C and below) in order to obtain optimum
yields; poor batch-to-batch reproducibility; the use of
exotic and expensive raw materials (for example,
dimethylgalliumhydroxide, as described in the Sinn et al.
publication mentioned below); or the use of unusual or
complicated reactors (for example, an autoclave reactor that
incorporates a milling action, as described in the Sinn et
al. article cited below, an ultrasonic reactor, as described
in U.S. Patent No. 4,730,071, or the use of a high speed,
high shear-inducing impeller, as described in U.S. Patent
No. 4,730,072).
At a symp~sium given in Hamburg, West Germany, in
September, 1987, H. Sinn et al. described several new
methods of preparing methylaluminoxane. Results of the
symposium are given in the following citation: H. W. Sinn
et al., Transition Metals and Organometallics as Catalysts
for Olefin Polymerization, W. O. Kaminsky et al., eds.,
Springer-Verlag, New York, Proceedings of an International
Symposium, Hamburg, FRG, September 21-24, 1987, pages 257-
268. On page 259 of this publication several unexpected
observations are detailed in regard to the use of ice in the
synthesis of methylaluminoxanes. However, page 262 does
contain a very cursory mention that tetraisobutyldi-
aluminoxane reacts with "a repeatedly added excess" of
trimethylaluminum by giving off triisobutylaluminum that is
distilled out of the reactive vessel together with the
excess of trimethylaluminum. The residue is said to be "an
oligomeric aluminoxane". No data is provided in regard to
this ill defined product nor is its performance as a
cocatalyst in olefin polymerization described in the
reference.
~_ ATA 5463 ~3~ 2015549
SUMMARY OF THE PRESENT lNv~Nl~lON
The instant invention relates to the synthesis of
methylaluminoxanes. It is possible to form methyl-
aluminoxanes by the reaction of a tetraalkyldialuminoxane
containing C2 or higher alkyl groups with trimethylaluminum
using an amount of trimethylaluminum which is not present in
stoichiometric excess. Also, the synthesis of
methylaluminoxanes can be achieved by the reaction of a
trialkylaluminum compound or a tetraalkyldialuminoxane
containing C2 or higher alkyl groups with water to form a
polyalkylaluminoxane which is then reacted with
trimethylaluminum. Further, methylaluminoxanes can be
synthesized by the reaction of a polyalkylaluminoxane
containing C2 or higher alkyl groups with trimethylaluminum
and then with water. As will be appreciated by a person of
ordinary skill in the art, the tetraalkyldialuminoxane and
polyalkylaluminoxane can be isolated as reagents for the
instant reaction or can be present in non-isolated form when
aluminum alkyls are initially reacted with appropriate
amounts of water to form them. It is within the spirit and
scope of the instant invention to cover these various
possibilities.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
In accordance with the first embodiment of the
present invention, methylaluminoxane is synthesized by
reacting a tetraalkyldialuminoxane containing C2 or higher
alkyl groups (either in isolated form or as a non-isolated
intermediate as earlier described) with trimethylaluminum.
The tetraalkyldialuminoxane has the formula:
~I !7
~_ ATA 5463 -4- 201554~
R R
Al-O-Al
R R
where R is the aforementioned type of alkyl group,
preferably a C2-C20 alkyl group which can be either straight
or branched chain or cycloalkyl including n-butyl,
cyclohexyl, isobutyl, n-hexyl, and the like. The amount of
trimethylaluminum used is an amount which is not in
stoichiometric excess. This is unexpected in view of the
above-mentioned Sinn et al. publication which only
indicates, in a cursory reference, the reaction of a
"repeatedly added excess of trimethylaluminum" with
"tetraisobutyldialuminoxane". The molar amount of
tetraalkyldialuminoxane to trimethylaluminum which can be
used in accordance with the present invention ranges from
about 1:0.1 to no more than 1:1. The reaction can be
conducted at temperatures of from about -10~C to about
150~C. The reaction can be run in hydrocarbon solvent
(e.g., toluene, heptane, cumene, etc.). Toluene is
preferred. As would be understood by the person of ordinary
skill in the art, solvents which are catalyst poisons (e.g.,
ethers, amines, etc.) would not be preferred materials for
use.
A second embodiment of the present invention involves
the synthesis of methylaluminoxanes by reacting a
polyalkylaluminoxane (either in isolated or non-isolated
form) with trimethylaluminum. The molar ratio of
trimethylaluminum to polyalkylaluminoxane can range from
about 0.1 to about 10. The polyalkylaluminoxane is of the
formula:
Il t'~
~_ ATA 5463 -5- 2015549
-~Al-O~x
where R is alkyl as defined above and x is an integer
greater than 1, for example up to about 50. The
polyalkylaluminoxane is derived from a trialkylaluminum
compound or from the aforementioned tetraalkyldialuminoxane
by reacting either of these materials with water under the
following reaction conditions: temperatures of about -20~C
to about 50~C, preferably 0-15~C with vigorous agitation
under an inert atmosphere (e.g., nitrogen, helium, or
argon). The reaction is advantageously conducted in a
solvent medium, e.g., a hydrocarbon solvent. In most
embodiments, evolved gases will be suitably vented to deter
pressure buildup within the reactor. The molar ratio of
trimethylaluminum to polyalkylaluminoxane reacted in
accordance with this embodiment of the present invention to
form the desired methylaluminoxane ranges from about 0.1:1
to about 10:1 on a contained aluminum molar basis. Heat
should be applied after trimethylaluminum addition (e.g.,
refluxing, such as at 110~C in toluene, is especially
preferred in order to speed up the reaction).
A third embodiment of the present invention involves
the reaction of the aforementioned polyalkylaluminoxane,
which contains C2 or higher hydrocarbyl, e.g., alkyl,
groups, with trimethylaluminum and then with liquid water.
This embodiment of the present invention is believed to
involve a complex between the trimethylaluminum reagent and
the polyalkylaluminoxane which is amenable to later reaction
with water to form the desired methylaluminoxane reagent.
The same general process as described for the second
embodiment can be employed. Unlike conventional methods,
I; f}
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",,,_
reaction with liquid water is controllable and provides
reproducibly a methylaluminoxane that gives high activities
in olefin polymerization.
Methylaluminoxane produced by conventional methods
results in an As (specific activity units) for ethylene
polymerization under st~n~Ard conditions of about lx106
(As = grams of polyethylene/gram Zr hr atm C2H4). Methyl-
aluminoxanes produced by the first described embodiment of
the instant invention showed an As as high as 5.7x105
whereas the use of tetraisobutyldialuminoxane or
trimethylaluminum alone, for example, showed poor
polymerization activity (an As of 103 or less). The second
embodiment of the instant invention has yielded As values as
high as 1.3x106. The third embodiment, involving
precomplexation of trimethylaluminum with polyisobutyl-
aluminoxane and subsequent reaction with water, for example,
has given As values as high as 3.7x106.
It has been found that the water to aluminum ratios
used to make the polyalkylaluminoxane reagent have an effect
on the activity (As) of the final methylaluminoxane. As is
apparent from the Examples given below, for example, the
highest polymerization activities, when
polyisobutylaluminoxane was prepared, were achieved at
H20/Al ratios for preparing the polyisobutylaluminoxane of
about 0.6 to about 1Ø. Polymerization activities were
lower both below that range as well as above it.
The methylaluminoxane product formed by the instant
process is believed to be a novel composition of matter.
Conventional methylaluminoxane, when hydrolyzed, gives
methane as the sole gaseous hydrolysis product due to the
presence of methylaluminum species therein. In contrast,
methylaluminoxanes of the instant invention, which is, in
reality, a "modified" methylaluminoxane ("MMA0"), also
contains alkyl substituents derived from the tetraalkyl-
" ,-1
~ 2015~49
ATA 5463 -7-
dialuminoxane and/or polyalkylaluminoxane reagents which are
reacted with trimethylaluminum. Therefore, the additional
presence of the aforesaid C2 or higher alkyl ligands in the
aluminoxane material will insure the presence of additional
C2 + alkane hydrolysis products (either gaseous or liquid
depending upon the size of the alkyl substituent): for
example, isobutane, n-butane, n-hexane, and the like. The
mole % methane and mole % other alkane depend on the
quantity of TMAL introduced. Methane content in the
hydrolysis gas typically ranges from about 20% to about 80%,
though higher or lower amounts are theoretically possible.
The balance is mostly alkane derived from the trialkyl-
aluminum starting material, i.e., isobutane, n-butane,
n-hexane, and the like.
Differences are also evident in comparing physical
states of isolated methylaluminoxanes of the instant
invention with that of conventional methylaluminoxane.
Conventional methylaluminoxanes have been characterized as
white solids. Methylaluminoxanes produced in accordance
with the instant invention when isolated from solvent
exhibit a range of physical states. Products from the first
process embodiment are typically clear, colorless liquids.
Products from the second embodiment range from clear,
colorless liquids to white solids depending on several
factors such as degree of oligomerization of the
polyaluminoxane, the TMAL/IBAO ratio, and the like.
Products from the third embodiment are typically clear,
colorless viscous liquids. However, products from the third
embodiment are likely to exhibit a range of physical states
depending on the reaction conditions used during
preparation, i.e., the degree of oligomerization of the
polyalkylaluminoxane, the TMAL/IBAO ratio, the H2O/TMAL
ratio, etc.
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~ ~ ~ 5 5 4 9
ATA 5463 -8-
Another distinguishing feature of the
methylaluminoxanes of this disclosure is their high
solubility in aliphatic hydrocarbons, such as heptane,
hexane and cyclohexane. Conventional methylaluminoxanes
exhibit limited solubility in such hydrocarbons.
Another aspect of the instant invention involves
metallocene/aluminoxane catalysts for olefin polymerization
and copolymerization and their use in such
(co)polymerization processes. The instant catalyst systems
differ from conventional metallocene/aluminoxane catalysts
in the aluminoxane component, i.e., the use of a modified
methylaluminoxane as described hereinbefore which contains
C2 or higher alkyl ligands in addition to methyl ligands.
The metallocene component of the instant catalyst is
known and are, for example, organometallic coordination
compounds of a Group IVB or Group VB metal of the Periodic
Table of the Elements (56th Edition of Handbook of Chemistry
and Physics, CRC Press ~1975~). Included are the
cyclopentadienyl derivatives (e.g., the mono-, di- and
tricyclopentadienyl derivatives) of such metals as
zirconium, hafnium, titanium, and vanadium. For example,
cyclopentadienyl zirconium compounds of the formulae
Cp2ZrCl2, Cp2Zr(CH3)Cl and CpZr(CH3)3, where Cp stands for
cyclopentadienyl can be used as the metallocene component.
other metallocene compounds which have been reported
include: isopropyl (cyclopentadienyl-l-fluorenyl)hafnium;
ethylenebis(4,5,6,7-tetrahydro-l-indenyl)dichlorozirconium;
and ethylenebis(indenyl)dichlorozirconium. Further details
in regard to this known class of metallocene compounds can
be found in the following patent documents~
U.S. Patent Nos .
4,404,344 and 4,542,199; International Patent Publication
Nos. WO 87/03604, Wo 88/02009, and WO 88/04672 to WO
88/04674.
" ,
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ATA 5463 -9_
The instant process and the resulting methyl-
aluminoxane products possess a number of advantages over
prior art procedures. If triisobutylaluminum (TIBAL) is
selected as to form the tetraalkyldialuminoxane or
polyalkylaluminoxane precursor, substantial economies may be
realized since TIBAL is relatively inexpensive. Also, the
critical initial reaction with TIBAL is much easier to
control with the analogous reaction with trimethylaluminum
thereby giving a less hazardous process. Reaction times to
produce the desired methylaluminoxanes are substantially
less than some prior art procedures (e.g., on the magnitude
of several hours as compared to several days when hydrated
salts are used as the water source). The instant process
uses no "carriers" of water (e.g., hydrated salts such as
aluminum sulfate or copper sulfate), thereby eliminating the
need to dispose of solid by-products. The use of the
relatively more expensive trimethylaluminum is made more
efficient since, in most cases, there is little or no loss
of insoluble methylaluminoxane species, i.e., yields are
essentially quantitative. In the first two embodiments,
recovery efficiencies of aluminum values charged as soluble
aluminum in methylaluminoxanes typically exceed 98%. In the
third embodiment, recovery efficiencies range from about 75%
to essentially quantitative and are dependent on reaction
parameters such as agitation rate, reaction temperature,
addition rate of water, scale of experiment, etc. The
reaction can be conducted at slightly above, at, or slightly
below ambient temperatures eliminating or minimizing the
need for extremely low temperature capability, for example,
in commercial reactors. The methylaluminoxane products give
olefin polymerization activities comparable, and in some
cases better, than methylaluminoxane prepared by other
methods. Unlike many conventional processes, the instant
processes are highly reproducible and afford excellent
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batch-to-batch uniformity in yields and methylaluminoxane
properties. Also, the resultant methylaluminoxanes from
batch-to-batch perform consistently in olefin
polymerization. Further, it is not necessary to isolate the
methylaluminoxanes and redissolve in toluene to achieve high
polymerization activities, as is the case with many
conventionally prepared methylaluminoxanes.
Each of the aforementioned reactions results in the
formation of a methylaluminoxane product which is believed
to be different from methylaluminoxane products formed by
prior art processes. Methylaluminoxanes of the present
invention are useful as cocatalysts in olefin and diene
polymerization and copolymerization as illustrated in the
Examples which follow.
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EXAMPLE 1
DIBAL-0, (tetraisobutyldialuminoxane) a commercial
product of Texas Alkyls, was produced by reaction of water
with triisobutylaluminum (TIBAL) in heptane using a
water/TIBAL ratio of about 0.5. Solvent was stripped at
58~-65~C under vacuum, and DIBAL-0 was isolated as a clear,
colorless, slightly viscous liquid. Analytical data on the
isolated DIBAL-0 are presented in Table I, below.
EXAMPLE 2
DIBAL-0 (88.1 grams) from Example 1 was subjected to
vacuum distillation conditions (< 4torr) and was heated to
107~C such that a small quantity of TIBAL (7.1 grams) was
removed. The polycondensed DIBAL-0 (PC DIBAL-0) was a
viscous liquid that was diluted with toluene to facilitate
handling. Analytical data on the polycondensed DIBAL-O in
toluene are also presented in Table I.
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.,.,_
EXAMPLES 3-6
TIBAL as a 25% solution in toluene was charged to a
300-mL flask under a nitrogen atmosphere. The flask was
equipped with a magnetic stirring bar and a thermocouple to
monitor the reaction temperature. Isobutylaluminoxane
(IBA0) solutions were prepared by controlled addition of
water to the TIBAL-containing solution in the temperature
range 0~-12~C with vigorous agitation. Water was added
dropwise over a two to five hour period by syringe using a
small bore needle (20 or 22 gauge). After addition of the
water was completed, the clear, colorless solution of IBAO
was heated to 70~-80~C to insure substantially complete
reaction and remove dissolved isobutane. Analytical data on
the IBA0 solutions are also summarized in Table I. In some
cases, solvent was removed by distillation, and the IBA0 was
isolated as a viscous liquid (at H2O~Al ratios of up to
about 0.7) or a white powder (at H2O/Al ratios of 0.88 and
higher). Analytical data on the isolated IBAO are also
given in Table I.
I I ,1
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~_ ATA 5463 -13-
TABLE I
PREPARATION OR IBAO COMPOUNDSa
IBAO Solutions
Hydrolysis Gas
Wt% (Mole %)
Example Product H2O/Al Al Isobutane Other~
1 DIBAL-O -0.5
2 PC DIBAL-Oe -0.5 9.7
3 IBAO 0.98 3.9
4 IBAO 1.21
IBAO 1.14
6 IBAO 0.88 3.8 96 4
Isolated IBAO
Hydrolysis Gas
Wt% (Mole %) Molecular Evolv~d
Example Product Al Isobutane Other~ WeightC_ Gasa_
1 DIBAL-O 18.4 954 410 1.8
2 PC DIBAL-Oe
3 IBAO 26.6 97 3 975 1.2
4 IBAO
5 IBAO
6 IBAO 25.8 9010 951 1.1
a Addition required two to five hours depending on scale of
experiment. Temperature at the start of the reaction was
in the range of 0-12~C. As the reaction proceeded,
temperature was allowed to increase to about 25~C. After
the reaction was completed, the temperature was then
increased to 70~C to remove the isobutane by-product.
b Others include predominantly hydrogen and isobutylene and
smaller amounts of propane and ethane.
c Cryoscopically in benzene.
d Expressed as moles gas per mole of aluminum.
e Polycondensed DIBAL-O.
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EXAMPLES 7-23
Using the same equipment as in Examples 3-6,
trimethylaluminum (TMAL) was added to the products of Table
I, above, to produce TMAL/IBAO or TMAL/DIBAL-O complexes.
The conditions used in production of the complexes are
presented in Table II, below. The TMAL/IBAO ratios in Table
II are calculated by dividing molar equivalents of Al in
TMAL by the molar equivalents of Al in IBAO or DIBAL-O.
TABLE II
PREPARATION OF TMAL/IBAO COMPLEXES
Example H2O/Al TMAL/IBAOa Conditions
7 0.5 1 A,E
8 0.5 1 A,F
9 0.5 1 A,C
0.5 0.5 A,C
11 0.98 1 B,C
12 1.21 1 B,C,G
13 1.21 1 B,C,H
14 1.14 1 B,C
0.98 1 B,D
16 0.98 0.5 B,D
17 0.5 0.25 A,C
18 0.88 0.5 B,D
19 0.88 0.5 B,D,I
0.88 0.5 B,D,J
21 0.88 0.5 B,D,K
22 0.88 1.0 B,D
23 0.88 0.25 B,C
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2015549
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TABLE II (CON'T)
PREPARATION OF TMAL/IBAO COMPLEXES
TMAL/IBAO Solutions
Wt% HydrolYsis Gas (Mole %) b
Example Al Methane Isobutane Other
11 7.8 68 24 8
12 4.9 79 20
13 6.8
14 7.3 73 26
7.4 76 22 2
16 5.8 60 37 3
18 5.8 61 38
19 8.2 58 36 6
14.6 54 38 7
21
22 7.5 71 25 4
23 4.8 35 63 2
Isolated TMAL/IBAO
Wt% Hydrolysis Gas (Mole %) Molecular Evolvdd
Example Al Methane Isobutane Other~ WeiqhtC Gas _
7 24.6e60 38 3
8 23.5e62 36 2
9 23.7e60 38 2
l~l 21.6e47 50 2
12
13
14
33.3f64 29 7 788 1.2
16 19.7f28 66 6
17
18
19
21 34.2f58 29 13 4810 1.3
22
23
..
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TABLE II (CON'T)
PREPARATION OF IBAO/TMAL COMPLEXES
CONDITIONS:
A - Neat TMAL and neat commercial DIBAL-O.
B - Toluene solutions.
C - IBAO/TMAL heated to 60-85~C for one hour.
D - IBAO/TMAL/toluene refluxed at 110~C for one to three
hours.
E - Concentrated by distillation of aluminum alkyl.
F - No heat.
G - Two-phase system obtained; analysis is of supernatant
only.
H - Two-phase system obtained; analysis is for total sample,
i.e., supernatant plus gelatinous lower phase.
I - Solvent removed via distillation resulting in a 25%
reduction in volume of sample.
J - Solvent removed via distillation resulting in a 50%
reduction in volume of sample.
K - Solvent removed to isolate solid TMAL/IBAO (0.88) = 0.5
a Ratio of moles Al in TMAL to moles Al in IBAO.
b Others include predominantly hydrogen and small amounts of
propane, isobutylene and ethane.
c Cryoscopically in benzene.
d Expressed as moles gas per mole of aluminum.
e Isolated product was a clear colorless liquid.
f Isolated product was a white solid.
~i n
_ ATA 5463 -17- 2015549
EXAMPLES 24-47
Products of examples in Table II, above, were used in
a standard ethylene polymerization test in a l-L Autoclave
Engineers Zipperclave reactor. Data are compiled in Table
III below. The procedure was as follows. High purity, dry
toluene (500 mL) was degassed with nitrogen and was charged
to the vessel. Using a syringe assembly, the various
cocatalyst samples produced in Examples 7-23 were charged
such that a total of 4xlO 3 mole of aluminum was introduced.
A dilute toluene solution of zirconocene dichloride (6xlO 8
to 4xlO 7 mole) was then charged to the vessel. The
contents were then heated to 90~C + 2~C unless otherwise
noted. Ethylene (150 psig) was introduced to the autoclave
while stirring the reactor contents at 1000 rpm. After 15
minutes, polymerization was terminated by blocking the flow
of ethylene with subsequent venting and cooling of the
vessel. Polyethylene was isolated as a white powder or a
white fibrous material. The melt index (MI) and high load
melt index (HLMI) were measured using ASTM D-1238,
Conditions E and F. The melt index ratio is obtained by
dividing HLMI by MI and is considered a measure of the
molecular weight distribution (MWD). A low MIR indicates a
narrow MWD.
~ ~ '?
2015549
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TABLE III
ETHYLENE POLYMERIZATIONS WITH
MODIFIED M~l~nY~ALUMINOXANE (MMAO)
AND ZIRCONOCENE DICHLORIDEa
MMAO Specific
Aluminoxane SourceActiv3ity
Example CocatalYst (Example~(x10 )
24 DIBAL-O 1 4.1
PC DIBAL-O/Toluene 2 6.1
26 TMAL/DIBAL-O = 1 7 110
27 TMAL/DIBAL-O = 1 7 250
28 TMAL/DIBAL-O = 1 7 570
29 TMAL/DIBAL-O = 1 8 18
TMAL/DIBAL-O = 1 9 270
31 TMAL/DIBAL-O = 0.5 10 200
32 TMAL/Toluene Trace
33 IBAO (0.98) 3 4.2
34 TMAL/IBAO (0.98) = 1 11 96
TMAL/IBAO (1.21) = 1 12 2.5
36 TMAL/IBAO (1.21) = 1 13 1.4
37 TMAL/IBAO (1.14) = 1 14 2.6
38 TMAL/IBAO (0.98) = 1 15 110
39 TMAL/IBAO (0.98) = 0.5 16 140
TMAL/DIBAL-O = 0.25 17 23
41 TMAL/IBAO (0.88) = 0.5 18 670
42 TMAL/IBAO (0.88) = 0.5 19 920
43 TMAL/IBAO (0.88) = 0.5 20 930
44 IBAO (0.88) 6 7.7
MAO/TolueneC 1000
46 TMAL/IBAO (0.88) = 1.0 22 670
47 TMAL/IBAO (0.88) = 0.25 23 93
", I
ATA 5463 -19-
zn ~554~ ~
TABLE III (CON'T)
ETHYLENE POLYMERIZATIONS WITH
MODIFIED METHYLALUMINOXANE (MMAO)
AND ZIRCONOCENE DICHLORIDEa
Melt
Aluminoxane Melt Index
ExamPle CocatalYst Index Ratio Comments
24 DIBAL-O Control
PC DIBAL-O/Toluene Control
26 TMAL/DIBAL-O = 1 2.3 16
27 TMAL/DIBAL-O = 1 1.3 16 86-96~C
28 TMAL/DIBAL-O = 1 0.4 16
29 TMAL/DIBAL-O = 1
TMAL/DIBAL-O = 1
31 TMAL/DIBAL-O = O.5
32 TMAL/Toluene Control
33 IBAO (0.98) Control
34 TMAL/IBAO (0.98) = 1
TMAL/IBAO (1.21) = 1
36 TMAL/IBAO (1.21) = 1
37 TMAL/IBAO (1.14) = 1
38 TMAL/IBAO (0.98) = 1 0.5 25
39 TMAL/IBAO (0.98) = 0.5 0.5 20
TMAL/DIBAL-O = 0.25
41 TMAL/IBAO (0.88) = O.5 0.4 15
42 TMAL/IBAO (0.88) = 0.5 0.4 15
43 TMAL/IBAO (0.88) = 0.5 0.5 16
44 IBAO (0.88) Control
MAO/TolueneC O.2 15 Control
46 TMAL/IBAO (0.88) = 1.0 0.3 17
47 TMAL/IBAO (0.88) = O.25
a Ethylene polymerizations were conducted using zirconocene
dichloride at 150 psig of ethylene at 90~C + 2 for 15
minutes unless otherwise noted.
b gPE/(gZr atmC2H4 hr)-
c MAO Droduced via reaction of TMAL with Al(OH)3.xH2O as
described in EP No. 315,234 published May 10, 1989.
C
ATA 5463 -20- 20155~9
"._
EXAMPLES 48-51
IBAO with a H2O/Al ratio of 0.88 + 0.01 was prepared
in toluene solution as described in Examples 3-6. TMAL was
then added, and the mixture was heated to 70-85~C for one
hour. The product was then cooled, and water was added
slowly by syringe using a small bore needle over a period of
20 minutes while stirring vigorously and controlling the
temperature in the range of 0~-10~C. The reaction proceeded
controllably with little or no solids or gel formation.
Recovery efficiencies of aluminum values charged as soluble
aluminum in the methylaluminoxane solutions in Examples 48,
50 and 51 were 93.3%, 99.5%, and 98.8%, respectively. The
resultant MMAO products were tested in ethylene
polymerization, described as before, and the resulting data
are presented in Table IV, below.
' 2015~49
,,~ ATA 5463 -21-
TABLE IV
ETHYLENE POLYMERIZATIONS
USING MMAO VIA TMAL/IBAO/H2O
Reactants
Example TMAL/IBAO _2O/TMAL
48 TMAL/IBAO (0.89' = 0.5 0.52
49 TMAL/IBAO (0.89 = 0.5 0.89
50 TMAL/IBAO (0.88, = 0.5 0.31
51 TMAL/IBAO (0.88) = 1.0 0.32
MMAO from TMAL/IBAO/H2O
Wt% Hydrolysis Gas (Mole %) b
ExampleAl Methane Isobutane Others
48 2.3 46 51 3
49 2.3 46 53
5.4 46 52 2
51 7.7 64 32 4
Specific Melt
Activi~yC Melt Index
Example(x10 L Index Ratio Comments
48 180
49 9.6
330 0.5 15 As of TMAL/IBAO (0.88)=
0.5 before H2O addition
was 240x103
51 1200 0.4 17 As of TMAL/IBAO (0.88)=
1.0 before H2O addition
was 670x103
a Ethylene polymerizations were conducted using zirconocene
dichloride at 150 psig of ethylene at 90~C + 2 for 15
minutes unless otherwise noted.
b Others include predominantly hydrogen and smaller amounts
of propane, isobutylene and ethane.
gPE/(gZr atmC2H4 hr)-
2û15549
ATA 5463 -22-
EXAMPLE 52
TIBAL as a 25% solution in toluene (246.4 grams of
solution containing 3.40% Al) was charged to a flask
equipped as described in Example 3-6. An IBA0 was then
prepared by addition of 3.92 grams of water (H20/Al = 0.70)
vla syringe over a 30-minute period while controlling
temperature between 0~C and 5~C. The clear, colorless IBAO
solution was then heated to 75~C to insure complete reaction
and to drive off dissolved isobutane. A sample of the IBA0
solution was then removed for analysis and showed 3.7% Al
and the hydrolysis gas composition was >98 mole % isobutane.
This IBAO solution was used in Examples 53 and 54 to produce
TMAL/IBAO.
A portion of the above IBAO solution was used to
isolate solvent-free IBA0. Toluene solvent was removed by
vacuum-stripping and mild heating (<60~C). IBAO (H20/Al =
0.70) was isolated as a clear, colorless but viscous liquid
with the following analytical values: 20.8% Al and 97%
isobutane in hydrolysis gas, and the evolved gas analysis
showed 1.4 mole of gas per g-atom of aluminum. The
molecular weight of the IBAO (cryoscopically in benzene) was
447.
EXAMPLE 53
To 90.0 grams of the IBA0 solution (3.7% Al) prepared
in Example 52 was added 8.80 grams of TMAL giving a
TMAL/IBA0 ratio of 1Ø The resulting solution was heated
to reflux for 60 minutes. Analysis of the TMAL/IBA0
solution showed 6.8% Al and the hydrolysis gas composition
showed 33 mole % isobutane and 63 mole % methane.
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ATA 5463 -23-
EXAMPLE 54
The same procedure as described in Example 53 was
followed except 107 grams o~ IBA0 solution from Example 52
and 5.22 grams of TMAL were charged to achieve TMAL/IBA0 =
0.5. The resultant TMAL/IBAO solution showed 5.7% Al and
48% methane, and 44% isobutane in the hydrolysis gas.
EXAMPLE 55
To 86.5 grams of toluene solution of TMAL/IBAO from
Example 53 was added 0.61 grams of H2O (H2O/TMAL = 0.31)
with vigorous agitation over a 40-minute period keeping
temperature between 0~C and 12~C. The product was
subsequently refluxed for 60 minutes. The resultant product
showed a very small (<1 mL) lower gelatinous phase and a
larger clear, colorless liquid. The product was shaken
vigorously to suspend the small lower phase and an analysis
of the total sample showed 6.9% Al and the hydrolysis gas
composition showed 30% isobutane and 65% methane.
EXAMPLE 56
Another IBA0 solution was prepared as in Example 52
with 242 grams of TIBAL/toluene solution and 3.84 grams of
H20 (H20/Al = 0.70). A sample was analyzed and showed 3.7%
Al. The hydrolysis gas composition was 94% isobutane. This
experiment shows excellent reproducibility of results
compared to Example 52.
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ATA 5463 -24-
EXAMPLE 57
A TMAL/IBAO = 1 was prepared as in Example 53 by
reaction of 180.8 grams of IBAO solution from Example 56 and
17.6 grams TMAL. Analysis showed 6.9% Al and the hydrolysis
gas showed 29 mole % isobutane and 66% methane. This
experiment shows excellent reproducibility of TMAL/IBAO
preparation compared to Example 53.
A similar but independent preparation of a TMAL/IBA0
(0.70) = 1.0 was conducted using IBAO from Example 52. The
solvent was removed vla mild heating and application of
vacuum affording a clear, colorless liquid. The distillate
contained 2.0% aluminum indicating some removal of volatile
aluminum alkyl (mostly TMAL) with the toluene. Analysis of
the isolated liquid product (still pot residue) showed 25.7%
Al and the hydrolysis gas showed 53% methane and 43~
isobutane. (This liquid product, when used in ethylene
polymerization, showed an As of 1.2 x 106 which is in good
agreement with the product of Example 53 and the product of
the first paragraph of this Example 57). The molecular
weight of the isolated product was determined to be 385
(cryoscopically in benzene). An evolved gas analysis showed
2.0 moles of gas per g-atom of aluminum.
EXAMPLE 58
The procedure of Example 55 was followed except to
89.2 grams of TMAL/IBAO (0.70) = 1 from Example 57 only 0.33
gram of H2O was added (H2O/TMAL = 0.16). A small lower
phase (<1 mL) was observed and analysis of the total sample
showed 6.9% Al and 63% methane, and 31% isobutane in the
hydrolysis gas.
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ATA 5463 -25- 2015~4~
",,
EXAMPLE 59
The procedure of Example 55 was followed except to
67.9 grams of TMAL/IBA0 from Example 57 was added 0.78 grams
of H2O (H2O/TMAL = 0.50). A small lower phase (<1 mL) was
again observed. Analysis of the total sample showed 7.0% Al
and 64% methane, and 33% isobutane in the hydrolysis gas.
EXAMPLE 60
Another preparation of TMAL/IBAO was made following
the general procedure described in Examples 52 and 56 except
on a larger scale. Thus, to 1501.7 grams of a 25% solution
of TIBAL in toluene in a 3-L flask was added 23.8 grams of
H20 (H20/Al = 0.7). Product solution was then heated to 70-
80~C for about 30 minutes to drive off isobutane. TMAL
(146.3 grams) was then added (TMAL/IBA0 - 1.0) and the
product refluxed for one hour. To the solution was added
18.3 grams of H20 by the procedure described in Example 55.
After addition of water, the solution was maintained at room
temperature with stirring for 16 hours, then heated to
reflux for 1-1/2 hours. A lower gelatinous phase formed
during water addition to the TMAL/IBA0 solution possibly
owing to Iess effective agitation in the larger flask.
However, after standing overnight, 1183 grams of clear,
colorless product was isolated by decantation which analysis
showed to contain 6.9% Al and 65% methane, and 28% isobutane
in the hydrolysis gas. The efficiency based on aluminum
recovered was 78%.
. .
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ATA 5463 -26-
EXAMPLES 61-67
Products from Examples 53-60 were evaluated in
ethylene polymerization as before except only 1 x 10 8 to
6 x 10 8 moles of zirconocene dichloride were used. Results
are compiled in Table 5.
Note that independently prepared MMAO from Examples
53 and 57 showed good agreement in ethylene polymerization
(As = 1.1 x 106 and 1.3 x 106, respectively). Note further
that those TMAL/IBAO solutions to which water was added
(Examples 55, 58 and 59) were more efficient cocatalysts in
ethylene polymerization than the TMAL/IBAO starting
materials. Note also that the scale-up product from Example
60 showed activity comparable to product from Examples 55,
58 and 59.
TABLE V
ETHYLENE POLYMERIZATION WITH MMAO
Specific Melt
MMAO MolesActivity Melt Index
ExampleSource Zr (10~) Index Ratio
61 Example 53 6x10 8 1100 0.4 14
62 Example 54 6x10 8 730 0.7 14
63 Example 55 lx10 8 2200 0.4 14
64 Example 57 6x10 8 1300 0.5 14
65 Example 58 2x10 8 3100 0.3 15
66 Example 59 lx10 8 3700 0.4 11
67 Example 60 2x10 8 3400 0.5 14
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ATA 5463 -27-
EXAMPLE 68
Tri-n-hexylaluminum (TNHAL) (52.7 grams) was mixed
with 98 grams of toluene. An g-hexylaluminoxane (NHA0) was
then prepared by addition of 2.36 grams of water (H20/Al =
0.70). The temperature was controlled between 0~ and 10~C.
The clear, colorless solution was then heated to 80~C to
insure complete reaction. A sample of the solution was
analyzed and showed 3.5% Al and the hydrolysis product was
97% hexane.
EXAMPLE 69
To 104.4 grams of the NHAO solution prepared in
Example 70 was added 9.2 grams of TMAL giving a TMAL/NHAO
ratio of 1Ø The resulting solution was heated to 96~C for
1-1/2 hours. Analysis of the TMAL/NHA0 solution showed 6.0%
Al.
EXAMPLE 70
To 34.5 grams of tri-g-butylaluminum (TNBAL) (13.4%
Al) was added 98.4 grams of toluene. The solution was
cooled and maintained at 0-10~C while 2.19 grams of water
were added over a 60-minute period. The solution was then
heated to 85~C to remove butane. The solution was treated
with 12.6 grams of TMAL and heated to 110~C for 90 minutes.
Analysis of the TMAL/NBA0 solution showed 6.9% Al and the
hydrolysis gas composition showed 33% g-butane and 66
methane.
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~ ATA 5463 -28- 2015549
EXAMPLE 71
To 97.4 grams of TMAL/NBAO solution (6.9% Al)
prepared in Example 72 was added 0.67 grams of water (H2O/Al
= 0.3) while maintaining the temperature at 0-5~C. The
resultant solution was heated to 90~C. Analysis of the
product showed 6.9% Al and the hydrolysis gas composition
showed 34% n-butane and 65% methane.
EXAMPLES 72-74
Polymerization of ethylene was performed as before
with product from Examples 69-71. Results are presented in
the table below.
TABLE VI
ETHYLENE POLYMERIZATION WITH MMAO
Specific Melt
MMAO Moles Activ~ty Melt Index
ExampleSource Zr (10 ) Index Ratio
72Example 69 4x10 77 67
73Example 70 lx10 270 1.0 14
74Example 71 lx10 7 250 0.5 28
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ATA 5463 -29-
EXAMPLE 75
From the preparation in Example 60, a 169.0 gram
portion was stripped of toluene using controlled vacuum at
60-70~C. A clear, colorless viscous liquid was obtained.
Analysis showed the isolated product to contain 29.5% Al and
56% methane and 37% isobutane in the hydrolysis gas. The
molecular weight was determined to be 670 (cryoscopically in
benzene). An evolved gas analysis showed 1.7 moles of gas
per g-atom of aluminum.
To 1.37 gram of isolated product, 6.45 grams of
toluene was added and the resultant solution was used in
polymerization. Specific activity of the reconstituted
product was 2.2 x 106. This activity is in reasonable
agreement with that observed (3.4 x 106) with the solution
prepared in Example 60.
EXAMPLE 76
To demonstrate that the instant methylaluminoxane
product can be prepared in heptane, 198.3 grams of TIBAL was
charged into a two liter flask under nitrogen atmosphere.
The flask was equipped with a mechAnical stirrer and a
thermocouple to monitor the temperature. Next, 591.4 grams
of heptane was added. The system was maintained between 10~
and 20~C. While 12.6 grams of water (H2O/Al weight
ratio:0.7) was added slowly. At ambient temperature, 74.2
grams of TMAL was added, and the solution was then heated to
the reflux temperature of heptane for thirty minutes. The
final solution was clear and colorless. The specific
activity tested at 2.7 x 106 grams PE/gm-Zr-atm-hr.
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ATA 5463 -30-
EXAMPLE 77
A sample of 70~.0 grams of the solution from Example
76 was retained in the flask equipped as described. While
the temperature was maintained between 0~C and -10~C, 7.2
grams of water (H20/TMAL weight ratio:0.45) was added. The
solution was slightly turbid. After settling and decanting,
600 grams of a clear solution comprising 7.3 wt% Al was
obtained. A specific activity test showed a value of
5.5 x 105 grams PE/gm Zr atm hr.
The foregoing Examples are set forth for illustrative
reasons only and should not be construed in a limiting
context. The scope of protection that is sought is set
forth in the claims which follow.
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