Note: Descriptions are shown in the official language in which they were submitted.
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
POLYALKYLALUMINOXANE COMPOSITIONS
FORMED BY NON-HYDROLYTIC MEANS
f
Background of the Invention
The present invention relates to a novel synthesis of
aluminoxanes by non-hydrolytic means and to novel
aluminoxane compositions. Aluminoxanes are well known as
components for olefin polymerization catalysts.
Aluminoxane compounds are chemical species that
incorporate A1-O-A1 moieties. While a wide range of
aluminoxane species are known, their exact structures are
not precisely known. The following structures (where R is
alkyl and X is an integer of from about 1 to about 40) have
been depicted:
R2A1-p-Alga
(R2A1-o-A1R2) 2
R- (RAlO) X-A1R2
(RAlO)x
Cyclic and cage cluster structures have also been
proposed. Such materials, as would be recognized by the
person of ordinary skill in the art are complex mixtures
of various species which can easily undergo dynamic
exchange reactions and structural rearrangements. A
recent review of these materials was authored by S.
Pasynkiewicz and appears in Polyhedron, Vol. 9, pp. 429-
453 (1990).
Methylaluminoxanes, sometimes termed
"polymethylaiumin-oxanes" (PMAOs) are well known materials
with wide utility in olefin polymerization using single-
1
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
site, or metallocene-based, polymerization catalyst
systems (See, for example, Col. 1, Lines 14-29 of U.S.
Patent No. 4,960,878 to C. C. Crapo et al.). PMAOs are
conventionally prepared by controlled hydrolysis of
trimethylaluminum (TMAL). Generally, hydrolysis occurs '
with some loss of aluminum to insoluble species.
Generally, PMAOs also have very low solubility in
aliphatic solvents, which limits their utility, as well as
poor storage stability for solutions containing them.
(See, for example, Col. 1, lines 30-46 of U.S. Patent No.
4,960,878). Finally, it is generally
polymethylaluminoxanes that have been the most useful
products of this general class of material: other
alkylaluminoxanes do not work as well. Since- TMAL is an
expensive starting material, the resulting PMAO is
expensive.
The problems of low yield, poor solubility, poor
storage stability, and expensive reagents in preparation
of PMAO have previously been attacked, with only limited
success, in several ways. One method was to make
predominantly PMAO, but include some components from
hydrolysis of other alum:i.num alkyls, to form the so-called
"modified methylaluminoxane" (MMAO). This yields
predominantly methyl-containing aluminoxanes in improved
yields, with improved solution storage stability as well
as improved solubility in aliphatic solvents, at lower
cost. However, since alkyl groups other than methyl are
present, these materials axe not always as effective as
conventional PMAO. '
The prior art contains certain disclosures which are
deemed to be particularly germane to the present
invention, including a series of related publications by
2
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
T. Mole and coworkers (E. A. Jeffrey et al., Aust. J.
Chem. 1970, 23, 715-724; A. Meisters et al., Journal of
. the Chemical Society, Chem. Comm. 1972, 595-596; D. W.
Harney et al., Aust. J. Chem. 1974, 27, 1639-7.653; A.
~ 5 Meisters et al., Aust. J. Chem. 1974, 27, 1655-1663; and
A, Meisters et al., Aust. J. Chem. 1974, 27, 1665-1672)
which describe the exhaustive methylation of oxygen-
containing organic substrates by trimethylaluminum
(hereinafter abbreviated as "TMAL" for simplicity). Some
of the reactions that these publications report are listed
hereinbelaw:
Ph3COH > Ph3CMe ( 1 )
Excess TMAL, 19 hrs., 80 °C
Ph2 (Me) COH > Ph2CMe2 (2)
Excess TMAL, 20 hrs., 85 °C
Ph (Me) 2COH > PhCMe3 (3)
Excess TMAL, 18 hrs., 110 °C
Me3COH > GMe4 (4 )
Excess TMAL, 42 hrs., 120 °C
(4-Me-Ph) 2C0 >(4-Me-Ph) 2CMe2 (5)
Excess TMAL, trace benzoic acid,
2 hrs., I70 °C
3
_ _..
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
PhC (O) Me > PhCMes ( 6) "
Excess TMAL, 65 hrs., 122 °C
Me2C0 > ~~ ( 7 )
Excess TMAL, 80 hrs., 175 °C
PhC02H > PhCMe3 ( 8 )
Excess fMAL, 24 hrs . , 130-150 °C
MeC02H > CMe4 ( g )
Excess TMAL, 23 hrs., 130 °C
This work focused on conversion of the organic
substrates, and only speculates occasionally on the aluminum
containing products formed. Some of the comments they do make
include, e.g., Equation (6) of Meisters et al.(Aust. J. Chem.
1974, 27, 1655-1663) which shows [MezAlOAIMe2] as a speculative
product; as well as Equation (6) of Meisters et al. (Aunt. J.
Chem. 1974 , 27 , 1665-1672 ) which al so shows [MezA1.0A1Me2 ] as a
speculative product. Another relevant comment made in these
disclosures is that these reactions do not remain homogeneous
tree the footnote on page 1643 of Harney et. al, Aust. J.
Chem. 1974, 27, 1639-1653).
4
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
Another relevant comment appears in Comprehensive
Organometallic Chemistry II, E.W. Abel et al., eds., New
. York NY, Pergamon, 1995, Vol. 1, p. 452 where several
preparations of aluminoxanes are given, including those
~ 5 set forth in Equations (54)-(57) and Scheme 8.
Aluminoxanes of these preparative methods, however, are
said to be unsuitable as cocatalysts for single-site
catalysts.
Another problem well known in the art a.s the
inevitable presence of trimethylaluminum (TMAL) in the
polymethyl-aluminoxane (PMAO) product. In particular, L.
Resconi et al, Macromol. 1990, 23, 4489-4491 and the
references cited therein show that PMAO prepared in the
normal manner contains both methylaluminoxane species as
well TMAL species. These researchers based their
conclusion on, among other things, the presence of two
signals in the iH NMR of PMAO. Fig. 1, which forms a part
of the present specification, illustrates the 1H NMR of
commercially available PMAO with the spectrum being
composed of both a broad peak, attributed to
methylaluminoxane species, and a distinct second peak,
attributed to trimethylaluminum species. M.S. Howie,
"Methylaluminoxane and Other Aluminoxanes-Synthesis,
Characterization and Production", Proceedings, MetCon '93,
pp. 245-266, Catalyst Consultants Inc., Houston, TX 1993,
has also noted that PMAO invariably contains TMAL. For
.instance, on page 247 it is stated that "MAO always
contains some amount of TMA". Further, Howie notes that
"total removal of TMA from MAO has not been demonstrated,
and reduction to low levels creates other problems".
9
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
Summary of the Tnvention
The present invention, in one embodiment, relates to
a novel composition which is a catalytically useful
composition comprising alkylaluminoxane which is
substantially free of trialkylaluminum content. The 1H NMR
of the product of this invention, for example, does not
Separately distinguish TMAT~ as a species which is present
therein.
This invention also relates to a process for forming
95 aluminoxanes from a particular type of aluminoxane
precursor composition, which will be described in greater
detail below, using non-hydrolytic means (e. g., by thermal
and/or catalytic means). The intermediate aluminoxane
precursor composition, which is ultimately capable of
being transformed by the aforementioned non-hydrolytic
means to the desired aluminoxane product, is formed by
treating a trialkylaluminum compound, or mixtures thereof,
with a reagent that contains a carbon-oxygen bond. This
treatment to form the intermediate aluminoxane precursor
composition is followed by the aforementioned non-
hydrolytic transformation of the intermediate aluminoxane
precursor composition to give a catalytically useful
aluminoxane composition. It should be clearly understood
that the process described herein can be used to form the
novel type of alkylaluminoxane referred to in the first
paragraph of this section of the specification as well as
conventional polymethylaluminoxane compositions that are
6
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
not substantially free of TMAL as a species which is
present therein as measured by the iH NMR spectrum of the
. product. It should also be recognized that the process
described herein is useful for the formation of
S alkylaluminoxanes, in general, as well as the formation of
polymethylaluminoxane. In most cases it may be desirable
to obtain a polymethylaluminoxane product with a low free
TMAr. content. However, the amount of free TMAIt remaining
in the aluminoxane composition may be adjusted from very
low levels to over 50~ by controlling the stoichiometry
and reaction conditions in the process.
The present invention, in a preferred embodiment,
enables one to produce polymethylaluminoxane compositions
of improved solution stability which also have the
desirable feature of compatibility with aliphatic
hydrocarbon solvents, such as hexane, heptane, octane or
decane. The process allows for high recoveries (yields)
of aluminum values in making the desired product. Also,
the process produces an methylaluminoxane product giving
high activities in polymerization of olefin monomer(s).
Description of the Drawings
The Drawings which form a portion of this
Specification are provided herewith to further illustrate
certain attributes of the present invention. Fig. 1
illustrates the 1H NMR of conunercially available PMAO with
the spectrum being composed of both a broad peak,
attributed to methylaluminoxane species, and a distinct
second peak, attributed to trimethylaluminum species.
Fig. 2 shows a novel PMAO product that can be made, in
accordance with one particular embodiment of the process
7
CA 02241091 1998-06-19
WO 97!23288 PCT/LJS96/19980
of the present invention, which is easily handled and
which performs well, but which is substantially free of
TMAL as a species that can be separately distinguished by
1H NMR .
Description of Preferred Embodiments
As just mentioned, preferred embodiments of the
present invention relate to (1) a process for forming, by
the non-hydrolytic conversion of suitably constituted
1~ alkylaluminoxane precursor compositions, catalytically
useful methylaluminoxane compositions, and (2)
polymethylaluminoxane compositions which are substantially
free of trimethylaluminum content and which are
catalytically useful methylaluminoxane compositions.
The intermediate precursor composition is an
organoaluminum composition which is constituted such that
it contains alkyl groups, initially bound to aluminum
which are capable of alkylation of groups, also contained
in the precursor, which contain a carbon-to-oxygen bond.
When the alkylation of such carbon-oxygen containing
groups occurs, the oxygen atoms contained in such groups
in the precursor are incorporated into alkylaluminum
moieties during that part of the present process in which
the intermediate precursor is transformed to the desired
aluminoxane product.
It will be appreciated by a person of ordinary skill
in the art that there are many ways of forming the
8
CA 02241091 1998-06-19
WO 97/23288 PCT/IJS96/19980
intermediate precursor composition which must contain some
amount of alkylaluminum groups as well as some carbon
which is chemically bound to oxygen and susceptible to
alkylation by an alkylaluminum group. For the purposes of
' S illustrating the nature of these precursor compositions,
the following discussion will provide examples of methods
for forming suitable compositions of that type. This
discussion, however, should not be construed as limiting
the present invention to the particular methods which may
be exemplified herein, for example, for preparing the
preferred aluminoxane precursor composition, which may
incorporate a wide range of chemical species therein
without precisely known chemical structure. For instance,
as will become apparent from the following description, if
a ketone, such as benzophenone, is reacted with a
trialkylaluminum compound, such as trimethylaluminum, an
addition reaction will occur. The result will be a.
composition containing alkylaluminum groups (in this case,
methylaluminum) and functional groups where carbon is also
bound to oxygen (in this case, a 1,1-Biphenyl-ethoxy
functional group):
Me3Al + 0 . 8 R2C=O > Me2 _ 2A1 ( OC ( Ph ) ~Me ) o _ a
Analogous precursor compositions can be formed in
alternative ways, as will be described in more detail
below. As another example, a salt metathesis reaction can
be depicted as follows:
Me2 . 2A1 Cl o . a + 0 . 8 NaOC ( Ph ) 2Me >
Me2_2A1 (OC (Ph) 2Me) 0.8 + O . 8 NaCl
9
CA 02241091 2003-08-19
WO 97!23288 PCTIUS96/19980
As earlier mentioned, the precursor intermediate
composition can be formed by using a reagent, containing a
carbon-to-oxygen chemical bond. Suitable reagents which can
be used can be selected from the alcohols, the ketones, and
the carboxylic acids as representative examples. A
particularly suitable inorganic reagent which has been found
to work is carbon dioxide.
In the preferred embodiment of the present invention,
this precursor composition is formed by treating
trimethylaluminum with an oxygenated organic compound such as
an alcohol, ketone, carboxylic acid or carbon dioxide. In the
case of carboxylic acids or carbon dioxide, some aluminoxane
moieties will form (see, for example, U.S. Patent Serial
No. 5,728,855). In all these cases, as is well known in
the art (see~for instance, the citations to exhaustive
methylation given above, and references cited therein),
alkoxyaluminum or arylalkoxyaluminum moieties will be
formed. The following equations represent possible, non-
limiting, examples of the reactions of trimethylaluminum
and oxygenated organic molecules to form alkoxyaluminum or
arylalkoxyaluminum-based aluminoxane precursor compositions
(R and R' being the same or different and being selected
from alkyl and/or aryl and TMAL indicating
2~ trimethylaluminum):
ROH + 2 Me3A1 > MeH + MesAl.z (OR) (I)
ROH + Me3Al. > MeH + 1 /2 (Me,Al2 (OR) 2) ( I I )
10
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
RC ( O ) R' + 2 Me3Al. > MesAl. Z ( OCMeRR' ) ( I i i )
RCO2H + 3 Me3Al. >
1/2 (Me9A1.2 (OCMe2R) 2) + IMe2AlOA1Me2~ (IV)
The most preferred embodiment of the present invention is
to use a carboxylic acid or carbon dioxide as they form both a
methylaluminoxane precursor containing the alkoxyaluminum or
arylalkoxyaluminum moieties and the desired methylaluminoxane
products.
Once this preferred methylaluminoxane precursor
composition is formed, the key component of the present
invention is the thermal and/or catalytic transformation of
this precursor to form the desired catalytically useful
methylaluminoxane composition. While the prior art teaches
that these precursor compositions can be transformed to form
exhaustively methylated organic derivatives, it does not
disclose the formation of catalyticaily active aluminoxane
compositions, nor does it teach the proper conditions to form
such a catalytically useful composition comprising methy-
laluminoxane. A recent review.in the prior art (Comprehensive
Organometallic Chemistry II, Vol. 1, p. 452) suggests, in
fact, that polymethylaluminoxane processes based on carboxylic
acid reagents "do not produce aiuminoxanes suitable for
catalytic applications". The prior art additionally fails to
a
recognize the aliphatic hydrocarbon solubility and
11
CA 02241091 1998-06-19
WO 97/23288 PCTNS96/19980
improved storage stability characteristics of the
preferred products of the process of the present invention
as well as the possibility of manufacturing the novel low
TMAL-containing product of certain embodiments of the
instant invention. The prior art appears to be silent on
exhaustive methylation of carbon dioxide. Furthermore, as
the Examples provided hereinbelow illustrate, we have
discovered conditions where this reaction remains
homogeneous, in contrast to the heterogeneous examples of
the prior art.
The present invention has also discovered that
formation of PMAO, for example, by the present invention
yields, in certain embodiments, a product substantially
free of TMAI, since separate signals for PMAO and TMAL are
not observed in the 1H NMR spectrum of the product.
The process of the present invention produces high
recoveries of aluminum as compared to hydrolytic processes
for making aluminoxanes as conventionally known to the
art. The process of the present invention also is capable
of producing polymethylaluminoxane with improved storage
stability as compared to hydrolytic processes for making
aluminoxanes as conventionally known to the art. Finally,
the process of this invention is capable of producing
polymethylaluminoxane in high yield in the presence of
aliphatic solvents, unlike hydrolytic processes for making
aluminoxanes as conventionally known i.n the art.
The preferred method for transforming the
methylaluminoxane precursor is to optionally add, or form
in situ, a catalytically effective amount of
methylaluminoxane with the precursor and heat the material
at the lowest temperature sufficient to effect conversion
to the desired methylaluminoxane composition in a
12
CA 02241091 1998-06-19
WO 97!23288 PCT/US96I1998fl
reasonable amount of time. This reaction can also be
facilitated by increasing the concentration of
~ organometallic species by removing, or limiting in other
ways, the amount of solvent, if solvent, which is an
optional ingredient at this point in the process, is
present.
The present invention, in its most preferred
embodiment is a navel process, for forming catalytically
useful polymethylaluminoxane with the resulting,
polymethylaluminoxane composition, in certain embodiments
being a novel polymethylaluminoxane composition which is
substantially free of trimethylaluminum. This process
comprises the thermal andfor catalytic transformation of
an appropriately constituted precursor composition as
earlier described. A preferred method for preparing the
precursor composition is treatment of trimethylaluminum
with a carboxylic acid or with carbon dioxide. However,
as will be appreciated by a person of ordinary skill in
the art, there are many other methods which can be used to
prepare the precursor composition which is transformed
into the desired final product.
If desired, supported polyalkylaluminoxane
compositions can be prepared by conducting the
aforementioned reaction in the presence of a suitable
support material. Alternatively, supported
alkylaluminoxanes may also be prepared by forming the
alkylaluminoxanes of this invention in a discrete,
separate step and subsequently allowing the
a
alkylaluminoxane to react with the support material..
Oxidic support materials, such as silica, are especially
preferred. It is preferred to have the alkylaluminoxane
in a suitable, heated solvent at a temperature high enough
73
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
(e. g. , at least 85°C, preferably about 100°C) so that the
alkylaluminoxane is in soluble form and, after being
combined with the support material, will come out of '
solution and contact that support as the total system is
alloowed to cool.
It has now discovered that the non-hydrolytic PMAO
("PMAO-IP") of the present invention has surprising
advantages over conventional, hydrolytically prepared PMAO
in the preparation of the aforementioned supported
methylaluminoxanes ("SMAO"). PCT Patent Publication No.
WO 96/16092 describes a supported catalyst component
prepared by heating a support material containing
aluminoxane under an inert atmosphere and at a temperature
sufficient to fix aluminoxane to the support material.
In this publication the alum:i.noxane and support are first
contacted in a diluent or solvent, which is removed prior
to the heat treatment step. This disclosure relies upon
the use of an aluminoxane which is prepared by the
controlled hydrolysis of trimethylaluminum species. The
instant application discloses novel, non-hydrolytic routes
to aluminoxanes, which have not previously been applied to
the problem of preparing a supported catalyst component.
Surprisingly, in accordance with the present invention, it
has been found that the utilization of non-hydrolytic
polymethylaluminoxane (PMAO-IP), instead of conventional,
hydrolytic, polymethylaluminoxane (PMAO), allows for the
preparation of a supported aluminoxane catalyst component
with high recovery of aluminum, with low extractable
aluminum, with superior ability to bind a transition metal
component, and which can be converted to a catalyst With
superior polymerization activity. When a corresponding
supported aiuminoxane catalyst component is prepared from
14
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
conventional, hydrolytically prepared PMAO, poor
recoveries of aluminum were observed, and the resulting
' supported aluminoxane catalyst component had an inferior
ability to bind zirconium, for example.
S As will be appreciated by the person of ordinary
skill in the art, the aluminoxane products that can be
made by the process of the present invention are useful as
cocatalysts in those single-site (metallocene-based)
catalyst systems which are useful in the polymerization of
olefin monomers in a manner analogous to that in current
use with the aluminoxane compositions that are currently
known and used in that manner.
The present invention will be further illustrated by
the Examples which follow.
15
a
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
EXAMPhES
Standard air-free glovebox and Schlenk line
techniques were used. Polymerization tests were conducted
in hexane at 85 °C, under a total pressure of 150 psig
(ethylene + hexane + hydrogen), using rac-
ethylenebisindenylzirconium dichloride:trimethylaluminum
1:30 as the catalyst precursor component with the
90 aluminoxane present at 1000:1 Al:Zr. Trimethylaluminum
(37.2 wt ~ Al) and polymethylaluminoxane (PMAO) in toluene
(9.0 wt ~ Al) were obtained from Akzo Nobel Chemicals
Inc., Deer Park TX, and used as received. Benzophenone
and benzoic acid were obtained from Aldrich Chemical Co.,
placed under a nitrogen atmosphere, and otherwise used as
received.
r
16
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
EXAMPLE 1
A solution of trimethylaluminum (2.00 g
trimethylaluminum, 15.6 g toluene) was treated with a
solution of benzophenone (4.02 g benzophenone, 15.6 g
toluene), and the resulting mixture heated at 60 °C for one
and one half hours to give a solution of alkylaluminum
arylalkoxides with the overall composition
( (CsHS) 2MeC0) o.8A1Me2.2. Analysis of this product by 1H NMR
showed it to be a mixture of the discrete compounds:
( (C6H5) 2MeC0) lAlMe2 and ( (CsH~) 2MeC0) ~A12Me5. This product
could be heated, as is, for many hours at 60 °C and remain
unchanged according to 1H NMR.
A catalytic amount of PMAO (0.35 g, 9.0 wt ~ A1) was
'i5 added to the alkylaluminum arylalkoxide solution, and the
mixture heated at 60 °C for 3.2 hours. At the end of this
time, analysis by 1H NMR showed that alkoxy aluminum
species were no longer present, and that aluminoxane
moieties were present. An ethylene polymerization test,
which normally yields about 700 kg PE/g Zr hr with
conventional PMAO prepared by Akzo Nobel Chemicals Inc.,
gave 1380 kg PE/g Zr hr using this polymethylaluminoxane
instead.
17
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
EXAMPLE 2
A solution of trimethylaluminum (2.00 g
trimethylaluminum, 3.10 g toluene) was treated with a
solution of benzoic acid
(1.35 g of benzoic acid in I8.4 g of toluene) at 0 °C.
Methane gas was evolved. Analysis by IH NMR showed this
mixture to contain PhMeaCOAl and Me-Al and A1-O A1
moieties. When this mixture was heated at 80°C for twenty-
four hours, no change occurred.
A catalytic amount of PMAO (0.83 g, 9.0 wt ~ A1) was
added to the alkylaluminum alkoxide and aluminoxane
solution, and solvent removed in vacuo, to give a clear,
slightly viscous liquid. This liquid was heated at 80°C
for 1 hr and 55 minutes, to give a clear, amorphous,
toluene soluble solid. Analysis by ~H NMR showed that
alkoxy aluminum species were no longer present, and that
aluminoxane moieties were present. As no insoluble
aluminum-containing byproducts were formed, this
preparation gave a quantitative yield of catalytically
useful polymethyl-alumi.noxane. In an accelerated aging
test, conducted at 50°C, the polymethylaluminoxane prepared
by this Example remained clear, homogeneous and free of
gels for up to ten days, while a conventional,
hydrolytically prepared, commercial PMAO showed gel
formation within three to five days at the same
temperature. An ethylene polymerization test gave 680 kg
PEjg Zr hr using this polymethylaluminoxane. -
18
CA 02241091 1998-06-19
WO 97!23288 PCT/IJS96/19980
EXAMPLE 3
' TMAL (15.00 g) was mixed with toluene (9.25 g) and
was then reacted with carbon dioxide (3.74 g) at room
temperature to form an alkoxyaluma.num and
alkylaluminoxane-containing PMAO precursor composition.
This mixture was heated at 100° C for twenty-four hours to
give a clear, viscous liquid whose 1H NMR showed it to have
been converted to PMAO. Alkoxyaluminum species were no
longer detectable by NMR analysis. As no insoluble
aluminum-containing byproducts were formed, this
preparation gave a quantitative yield of catalytically
useful polymethylaluminoxane. A polymerization test with
this material yielded 2400 kg PE/g Zr hr in a thirty
minute test.
3
19
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
EXAMP7~E 4
Using the same procedure that is described in Example
2, TMAL (8.00 g) in 9.51 g of toluene was treated with
neat benzoic acid (5.40 g) to give an arylalkoxyaluminum-
containing methylaluminoxane precursor. Heating of this
mixture at 80°C for five hours gave conversion to PMAO. As
no insoluble aluminum-containing byproducts were formed,
this preparation gave a quantitative yield of
aatalytically useful polymethylaluminaxane.
Fig. 1 shows the Me-AZ region of a 1H NMR spectrum of
conventional PMAO obtained from a commercial source. The
95 spectrum clearly contains two signals, a broad signal due
to methylalumi.noxane species, and a sharper signal due to
trimethylaluminum species. Fig. 2 shows the same region
of the spectrum of PMAO prepared in this Example. Unlike
the commercially available PMAO, the material of this
invention shows only one broad signal in the depicted
region. The product is substantially free of TMAL in that
no distinct ~H NMR signal from TMAL is discernible.
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
EXAMPLE 5
A solution of trimethylaluminum (8.0 g in 4.94 g of
decane) was treated with carbon dioxide (1.9 g of carbon
dioxide) over a period of eight hours. Analysis by 1H NMR
showed this mixture to contain (CH3)3C0-Al, CH3-A1, and A1-
O-Al moieties. Heating this sample at 100°C for twenty-
four hours caused no change in the iH NMR spectrum.
However, when heated for five hours at 120°C, the reaction
mixture became slightly hazy, forming a viscous liquid
after cooling. Since it was not necessary to separate
solid, aluminum-containing byproducts from this product,
this preparation gave a quantitative yield of
catalytically useful polymethylaluminoxane. Analysis by 1H
NMR showed signals due to decane solvent, traces of
residual t-butoxy signals, and a broad signal due to
methylaluminoxane species.
An ethylene polymerization test gave 1100 kg PE/g
Zr/hr using the polymethylaluminoxane prepared in this
Example.
21
CA 02241091 2003-08-19
WO 97lZ3288 PCT/US96/19980
EXAMPLES 6-15
All manipulations in these Examples were conducted
with the best available air-free techniques, including
Schlenk line manipulations and inert atmosphere glove-box
techniques. On-line monitoring of the box atmosphere
generally showed 0.1-1.5 ppm oxygen (with brief excursions
to 2-6 ppm when opening the ante-chamber door) and 0.5-3
ppm water (with excursions to about 6 ppm).
Polymerization tests were conducted in a jacketed one
liter stainless steel ZIPPERCLAVE autoclave from Autoclave
Engineers. The polymerization reactions were conducted
with 150 psig ethylene supplied on demand to a reactor
charged with 25-50 mg of the catalyst (containing 1-2
micromoles Zr, depending on expected activity and planned
test duration), 500 mL hexane, and 2 mmole TEAL (present
as a scavenger). Prior to each polymerization test, the
reactor body was removed and oven dried for one hour at
100°C-120°C (with water drained from the heating/cooling
jacket). The reactor was always reassembled while the
body was still hot from the oven, and purged with nitrogen
for 15-30 minutes while the reactor cooled somewhat.
After purging, the recirculating bath was reconnected, and
the reactor heated to 50°C. The reactor Was pre-treated
with TEAL (0.2 mmole) in hexane (300 mL).
xs
Prior to use, DAVISON 948 micro-spherical silica was
dehydrated by calcination in a nitrogen fluidized bed.
Table 1 summarizes silica used in this work.
Non-hydrolytically prepared polymethylalumi.noxane
(PMAO-IP) was prepared according to the general teachings
of Example 3 contained herein.
22
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
Table 1. Calcination results.
a
Calcinationwt. lossResidual
Temp. C (~) OH
mmole/g
' Silica 200 C 3.9 1.52
A
Silica 400 C 6.z 1.06
B
Silica 400 C 5.5 1.06
C
Silica 600 C 7.1 0.65
D
Silica 600 C 6.2 0.71
E
General Procedure for Making SMAO: This is the
procedure used for all the samples in Tables 2 and 3. A
three-neck glass reactor (250 mL), equipped with gas
inlet, fritted-glass barrier gas-outlet, temperature
sensor and overhead stirrer (crescent-shaped paddle) was
placed under a nitrogen atmosphere and charged with 10.11
g silica (Silica D). Toluene (45 g) was added to form a
slurry, and stirring was begun. An aliquot of PMAO-IP
solution (14.91 g, 14.8 wt ~ A1) was then added, dropwise,
over 0.5 hour with stirring at 23-24°C. After the addition
was completed, the reaction mixture was heated to 100°C in
order to inure solubilization of the PMAO-IP, and was held
at that temperature for one hour. After the reaction
mixture had cooled back to room temperature, it was
transferred via a 1/4 inch outer diameter polyethylene
tube cannula to a bottom-fritted three-neck glass reactor
(250 mL), equipped with gas inlet, fritted-glass barrier
gas-outlet, and temperature sensor. The supernate was
removed, and the SMAO product was isolated by filtration
through the bottom frit. The filtrate was collected and
was set aside for analysis. The SMAO was then vacuum
dried in a bath at 50°C to obtain a free-flowing powder.
The results are sun~narized in Tables 2 and 3 which follow:
23
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
04
N 'd:M r M
N '
rN ~ CM
r rr r r
O
ri O
Q ~ ~!W~ ~-~-
ui~ ON ~ ,~
Nr a
N
dl
Q
~
N ~ ~N CVT.
~ ~ ~~ c~0~ c
t00
I-' N
~
~
N
~
Q'
O O ~ U
Q C
~
N
..
.
O
o O M r00M M ~ CW
'~if i i a .
~
~
N
'
'
uc c c~ ~N
- rr r r o ~ a
~ ~
o
c
~r
y ~ t COCDO o o Q..,-
~
N
X
O c'a
'v
as
Cl~ .r-1C 'O,
~ aa a a ',-'- N
~--'
...:
~
~
L
o
ai
O o
O OO O O _ M M00r O r- -p
O ~' O O '
O
~
f1
c Q aQ a a ~ cn 0 00 v o 0
Q
3
~ ~ Qa a.~
-t ~
tn
a
~
, , ~ m
.C~ O a
m
a's
~
'o
~
~
Q Q TU
a ~ ~ W ~
-o
m
ca
a~
~
(/~ ~ o oo o r' ~ c c a~c a a N
r Nr-a- o o o
C~
C
i
~
Q G?D Llll1J4-1 N~tch.-M ~ t
O ~ ~ N'_N dvM n
~ ~ ~ ~ C
_ U ~~ ~ ~ a ~ ~ re-r r r
tnu Wninin'cn~ E' cg. ~ a
~
_ ~ c ~
~
(n OPt00000N N E ~ ~ 3
p~~ r a-~-r
a ~ ,.,.~ a,O a a' 0 00 0 0 0 ~
~ ".. _ ~
cua~a~a.>~ _
_
~ ~ ~ E
E
_ _
J Ca O (~
E EE E
E c ccacaE '~ X co~ aoo> .~ o ' o ~
a a
~ X~ x N a~ iua~a~a~a~a>o ~
uJu~ -- - - - ~ ~o
t U 1 EE E E E E ~
J j "
'
td tC E esk O O X ~
O ~
~ ' O w. t
'
H C~ U y!JJ! ~ UJ U
( C IL U !.L I-
Llt L1J N (h C tW
24
CA 02241091 1998-06-19
WO 97/23288 PCT/US96119980
Conversion to catalyst:
The SMAO samples in Table 3 were converted to single-site based
ethylene polymerization catalysts by allowing up to 1 Zr:100 A1 to
bind with the SMAO from a solution of a bis-indenyl dimethylzirconium
(BIZ-M) in toluene. A 250 mL catalyst preparation flask (3 neck flask
with bottom frit), with an ace-threaded gas inlet adapter containing a
thermocouple, a stopper, and a fritted gas adapter, was set up and was
tested for vacuum. Working in the glovebox, the apparatus was charged
with 5 grams of the selected SMAO sample, and the central stopper was
replaced With an overhead stirring shaft. At the same time, one lO g,
and three 15 gram charges of dry toluene were set up in serum-capped
sample vials. Also prepared at this time was a 50 mL septum bottle
with BIZ-M (usually about 100 mg) and a small stir bar. Enough
toluene (typically 30 g) was added to obtain complete dissolution.
Working on a Schlenk line, the first 10 g charge of toluene was
used to slurry the silica. Gentle stirring was then begun. Enough
BIZ-M solution to provide 1 Zr:100 A1 in the SMAO sample was then
added, and the mixture was heated to 50°C for one hour and was then
filtered. The catalyst was then washed with two of the 15 g toluene
charges. All the filtrates were combined.
The stirrer was replaced with a stopper, and the catalyst was
vacuum dried at room temperature until ~~fountaining" of catalyst (due
to out-gassing of solvent vapors) was no longer observed (generally
less than thirty minutes). After this, the catalyst was dried for an
additional thirty minutes at room temperature, and then thirty more
minutes at 35 °C. Tables 4-6 which follow gives a summary of the
catalyst preparations and performance data:
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/19980
O MCDO M N 01
O
M~ M N N
D
H
C
O
V tor M 0fCOP
tdtittnd'sh11~
G
rN M
N N
L
L
Q
O Q N
MO O
d O O fl-
a ~"'Pr r r r r C
O
N
T
D3 T
y L -.R-. N ..'
N p_ O 0. U
E
fI. cO O cN0 dJ
,a,CO0OCO~ ~ ~ t .~w
1~.V V V V V
_
.~,
~ ~
O
cE
~ L
-.Z,~.tN ~ c~cc~ N
~ ~~
o~aso00~~ of ~
.: -
~L
P0saDO M d'
NM M efetd'~ cB
00 0 0 0 0 ~
'~
c~E'O~ N
~
c
/~
,-1
?~ U ~ ~
ca a ~
N
t
0 ..
MM O O O O
fl) -O p O O ~
a a ~
y Y
O _
OC p)
N N
V V V V _
__
'
E
v a
PcDeta0M tt~
~
OO 1'CDC107t
/i ~ L O C ~ c
.
E o .E E o E
Ofet070tM O c N c c O
Q M
~ a-r r M ch r
a0P r r r r
C1
N
_ r N M ~tttf~
r.s r P r P P
f!t O1C!C>'C1CX O cE O ~ ~
~
M
U (~W W W W W ~,
t~! '~c""'
upc
u
L
~~o
~
_~ ~... ~.-.
~, a
a
c8 ~ O~ ~i>'i>K>K ~ U ti. U U ti U
ca
H fI~ C7W tLtittit1.lJ ~ ~~ ~ d,
(n
26
CA 02241091 1998-06-19
WO 97/23288 PCT/US96/1998~
Table 6. Summary of oertormance results.
SMAO Cat. Activity D10 PBD
Sam Sam !e k PEI hr D50 /mL
to D90
microns
Com Com B 0.5 -- - - 0.39
A
Ex.6 Ex.11 0.6 306 388 468 0.32
Ex. Ex.12 0.T -- -- 0.34
T
Ex.8 Ex.13 0.65 - - --- 0.34
Ex. Ex. 14 1.6 432 507 573 0.36
9
Ex. Ex. 15 1.3 _ 451 492 0.36
10-~ 392
The data show above shows that PMAO-IP binds more
completely to calcined silica than conventional PMAO-IP, allows
for the preparation of SMAO With a higher aluminum loading, and
results in SMAO that binds more completely to zirconium species
thereby forming a more active catalyst.
The foregoing Examples, since they merely illustrate
certain embodiments of the present invention, should not be
construed in a limiting sense. The scope of protection sought
is set forth in the claims which follow.
27
