Note: Descriptions are shown in the official language in which they were submitted.
SUPPORTED KETIMIDE CATALYSTS FOR IMPROVED REACTOR CONTINUITY
FIELD OF THE INVENTION
The present invention relates to improving the continuity of a ketimide ligand
containing catalyst/reaction in a dispersed phase (i.e. gas phase, fluidized
bed or stirred
bed or slurry phase) olefin polymerization. There are a number of factors
which impact
on reactor continuity in a dispersed phase polymerization. Particularly there
may be
fouling which will decrease catalyst productivity and reactor operability. The
decrease
in catalyst productivity or activity is reflected by a decrease in ethylene
uptake over
time.
BACKGROUND OF THE INVENTION
Ketimide ligand containing catalysts for the polymerization of alpha olefins
were
introduced in U.S. patent 6,114,481 issued Sept 5, 2000 to McMeeking et al.
assigned
to NOVA Chemicals. These catalysts may be considered single site type
catalysts.
These catalysts are more active than the prior Ziegler Natta catalysts, which
may lead
to issues of polymer agglomeration. Additionally, static may contribute to the
problem.
As a result reactor continuity (e.g. fouling and also catalyst life time) may
be a problem.
The kinetic profile of many single site catalysts starts off with a very high
activity
over a relatively short period of time, typically about the first five minutes
of the reaction.
The profile then goes through an inflection point and decreases rapidly for
about the
next five minutes and thereafter there is period of relative slower decline in
the kinetic
profile. This may be measured by the ethylene uptake, typically in standard
liters of
ethylene per minute in the reactor.
There is no prior art that the Applicant is aware of which expressly discloses
a
process to modify (improve) the kinetic profile of a catalyst containing a
ketimide ligand.
There are a number of patents which teach modified porous inorganic supports
for
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polymerizations using single site catalysts. However, none of these patents
expressly
disclose that the kinetic profile of the resulting catalyst is modified.
United States patent 6,734,266 issued May 11, 2004 to Gao et al., assigned to
NOVA Chemicals (International) S.A., teaches sulfating the surface of a porous
inorganic support with an acid, amide or simple salt such as an alkali or
alkaline earth
metal sulphate. The resulting treated support may be calcined. Aluminoxane and
a
single site catalyst, including a ketimide containing catalyst, are
subsequently deposited
on the support. The resulting catalyst shows improved activity. However, the
patent
fails to teach or suggest depositing zirconium sulphate on a silica support.
United States patent 7,001,962 issued Feb 21, 2006 to Gao et al., assigned to
NOVA Chemicals (International) S.A., teaches treating a porous inorganic
support with
a zirconium compound including zirconium sulphate and an acid such as a
fluorophosphoric acid, sulphonic acid, phosphoric acid and sulphuric acid. The
support
is dried and may be heated under air at 200 C and under nitrogen up to 600 C.
Subsequently a trialkyl aluminum compound (e.g. triethyl aluminum) or an
alkoxy
aluminum alkyl compound (e.g. diethyl aluminum ethoxide) and a single site
catalyst,
including a ketimide containing catalyst, are deposited on the support. The
specification teaches away from using aluminoxane compounds. The activity of
these
supports is typically lower than the activity of the catalyst of U.S. patent
6,734,266
(compare Table 5 of U.S. patent 7,001,962 with Table 2 of U.S. patent
6,734,266). The
present invention eliminates the required acid reagent that reacts with the
zirconium
compound.
Canadian Patent Application 2,683,019 filed Oct. 20, 2009 discloses a process
to improve the dispersed phase reactor continuity of catalyst having a
phosphinimine
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ligand by supporting the catalyst on a support treated with a number of
compounds
including Zr(SO4)2.4H20. The support is also treated with MAO.
United States patent 7,273,912 issued Sept 25, 2007 to Jacobsen et al.,
assigned to Innovene Europe Limited, teaches a catalyst which is supported on
a
porous inorganic support which has been treated with a sulphate such as
ammonium
sulphate or an iron, copper, zinc, nickel or cobalt sulphate. The support may
be
calcined in an inert atmosphere at 200 to 850 C. The support is then activated
with an
ionic activator and then contacted with a single site catalyst. The patent
fails to teach
aluminoxane compounds and zirconium sulphate.
United States patent 7,005,400 issued Feb. 28, 2006 to Takahashi assigned to
Polychem Corporation teaches a combined activator support comprising a metal
oxide
support and a surface coating of a group 2, 3, 4, 13 and 14 oxide or hydroxide
different
from the carrier. The support is intended to activate the carrier without the
conventional
"activators". However, in the examples the supported catalyst is used in
combination
with triethyl aluminum. The triethyl aluminum does not appear to be deposited
on the
support. Additionally the patent does not teach ketimide catalysts.
United States patent 7,442,750 issued Oct. 28, 2008 to Jacobsen et al.,
assigned to Innovene Europe Limited, teaches treating an inorganic metal oxide
support typically with a transition metal salt, preferably a sulphate, of
iron, copper,
cobalt, nickel, and zinc. Then a single site catalyst, preferably a
constrained geometry
single site catalyst and an activator are deposited on the support. The
activator is
preferably a borate but may be an aluminoxane compound. The disclosure appears
to
be directed at reducing static in the reactor bed and product in the absence
of a
conventional antistatic agent such as STADIS . The patent fails to teach or
suggest a
catalyst containing a ketimide ligand.
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United States patent 6,653,416 issued Nov. 25, 2003 to McDaniel at al.,
assigned to Phillips Petroleum Company, discloses a fluoride silica¨zirconia
or titania
porous support for a metallocene catalyst activated with an aluminum compound
selected from the group consisting of alkyl aluminums, alkyl aluminum halides
and alkyl
aluminum alkoxides. Comparative examples 10 and 11 show the penetration of
zirconium into silica to form a silica-zirconia support. However, the examples
(Table 1)
show the resulting catalyst has a lower activity than those when the supports
were
treated with fluoride.
Apart from U.S. 6,734,266 and 7,001,962 noted above none of the above art
teaches catalyst containing a ketimide ligand.
The use of a salt of a carboxylic acids, especially aluminum stearate, as an
antifouling additive to olefin polymerization catalyst compositions is
disclosed in United
States patent numbers 6,271,325 (McConville et al. to Univation) and 6,281,306
(Oskam et al. to Univation).
The preparation of supported catalysts using an amine antistatic agent, such
as
the fatty amine sold under the trademark KEMAMINE AS-990, is disclosed in U.S.
patents 6,140,432 (Agapiou et al. to Exxon) and 6,117,955 (Agapiou et al. to
Exxon).
Antistatic agents are commonly added to aviation fuels to prevent the buildup
of
static charges when the fuels are pumped at high flow rates. The use of these
antistatic agents in olefin polymerizations is also known. For example, an
aviation fuel
antistatic agent sold under the trademark STADISTm composition (which contains
a
"polysulfone" copolymer, a polymeric polyamine and an oil soluble sulfonic
acid) was
originally disclosed for use as an antistatic agent in olefin polymerizations
in U.S. patent
4,182,810 (Wilcox to Phillips Petroleum). The examples of the Wilcox '810
patent
illustrate the addition of the "polysulfone" antistatic agent to the isobutane
diluent in a
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commercial slurry polymerization process. This is somewhat different from the
teachings of the earlier referenced patents - in the sense that the carboxylic
acid salts
or amine antistatics of the other patents were added to the catalyst instead
of being
added to a process stream.
The use of "polysulfone" antistatic compositions in olefin polymerizations is
also
subsequently disclosed in:
1) chromium catalyzed gas phase olefin polymerizations, in U.S. patent
6,639,028 (Heslop et al. assigned to BP Chemicals Ltd.);
2) Ziegler Natta catalyzed gas phase olefin polymerizations, in U.S. patent
6,646,074 (Herzog et al. assigned to BP Chemicals Ltd.); and
3) metallocene catalyzed olefin polymerizations, in U.S. patent 6,562,924
(Benazouzz et al. assigned to BP Chemicals Ltd.).
The Benazouzz et al. patent does teach the addition of STADISTm antistat agent
to the polymerization catalyst in small amounts (about 150 ppm by weight).
However,
in each of the Heslop et al. '028, Herzog et al. '074 and Benazouzz et al.
'924 patents
listed above, it is expressly taught that it is preferred to add the STADISTm
antistat
directly to the polymerization zone (i.e. as opposed to being an admixture
with the
catalyst).
None of the above art discusses polymerization catalysts containing a ketimide
ligand on a support which has been treated with Zr(SO4)2=4H20, let alone the
kinetic
profile of such a catalyst system.
The present invention seeks to provide a novel ketimide catalyst and support
system suitable for use in a dispersed phase polymerization.
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SUMMARY OF THE INVENTION
The present invention provides a catalyst comprising an organo group 4 metal
complex containing a ketimide ligand and a calcined inorganic support
impregnated
with not less than 1 weight % of Zr (SO4)2 to provide from 0.010 to 0.50 mmol
of Zr from
the sulphate per gram of impregnated support.
In a further embodiment the ketimide has the formula:
Sub 1 Sub 2
\ /
II
wherein Sub 1 and Sub 2 are independently selected from the group consisting
of C1-20
hydrocarbyl radicals which are unsubstituted or may be substituted by up to 4
hetero
atoms selected from the group consisting of N,O, and S or up to three C1-9
straight
chain, branched, cyclic or aromatic radicals which may be unsubstituted or
substituted
by a 01-6 alkyl radical or Sub 1 and Sub 2 taken together may form a saturated
or
unsaturated ring which may be substituted by up to 4 hetero atoms selected
from the
group consisting of N,O, and S and which ring may be further substituted by up
to three
Ci_s straight chain, branched, cyclic or aromatic radicals which may be
unsubstituted or
substituted by one or more C1-6 alkyl radicals.
In a further embodiment the complex containing the ketimide ligand has the
formula:
LmKn MY0
wherein M is a group 4 metal having an atomic number less than or equal to 72,
L is a
monoanionic ligand selected from the group consisting of a cyclopentadienyl-
type
ligand, K is a ketannide ligand, Y is independently selected from the group
consisting of
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activatable ligands, m is 0 or 1, n is 1 or 2, o is an integer and the sum of
m+n+o equals
the valence state of M.
In a further embodiment the support further comprises an activator of the
formula
R122A10(R12A10)AIR122
wherein each R12 is independently selected from the group consisting of C1-20
hydrocarbyl radicals and q is from 3 to 50 to provide from 50 to 500 parts by
weight per
part by weight of group 4 metal from the ketimide containing catalyst.
In a further embodiment L is selected from the group consisting of a
cyclopentadienyl radical, an indenyl radical and a fluorenyl radical which
radicals are
unsubstituted or up to fully substituted by one or more substituents selected
from the
group consisting of a fluorine atom, a chlorine atom, Ci_4 alkyl radicals and
a phenyl or
benzyl radical which is unsubstituted or substituted by one or more fluorine
atoms.
In a further embodiment Y is selected from the group consisting of a chlorine
atom, a methyl radical, an ethyl radical and a benzyl radical.
In a further embodiment in the activator R12 is a C1-4 alkyl radical and q is
from
10 to 40.
In a further embodiment M is a group 4 metal.
In a further embodiment the catalyst comprises from 50 to 250 ppm based on the
weight of the supported catalyst of an antistatic comprising:
(i) from 3 to 48 parts by weight of one or more polysulfones comprising:
(a) 50 mole % of sulphur dioxide;
(b) 40 to 50 mole % of a C6-20 an alpha olefin; and
(c) from 0 to 10 mole % of a compound of the formula ACH=CHB where A is
selected from the group consisting of a carboxyl radical and a C1-15 carboxy
alkyl
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radical and B is a hydrogen atom or a carboxyl radical provided if A and B are
carboxyl radicals A and B may form an anhydride;
(ii) from 3 to 48 parts by weight of one or more polymeric polyamines of
the formula:
RNRCH2CHOHCH2NR1)a-(CH2CHOHCH2NR1-R2-NH)b-(CH2CHOHCH2NR3)c-H]xH2-x
wherein R1 is an aliphatic hydrocarbyl group of 8 to 24 carbon atoms; R2 is an
alkylene
group of 2 to 6 carbon atoms, R3 is the group R2-HNR1; R is R1 or an N-
aliphatic
hydrocarbyl alkylene group having the formula R1NHR2, a, b and c are integers
from 0
to 20 and x is 1 or 2; with the proviso that when R is R1 then a is greater
than 2 and b =
c = 0, and when R is R1NHR2 then a is 0 and the sum of b+c is an integer from
2 to 20;
and
(iii) from 3 to 48 parts by weight of 010-20 alkyl or arylalkyl sulphonic
acid.
In a further embodiment the ketimide ligand has the formula:
RN
NCrN
wherein each R1 is independently selected from the group consisting of a
phenyl radical
which is unsubstituted or substituted by up to three C1-4 alkyl radicals.
In a further embodiment the catalyst may be prepared by:
1) impregnating a porous particulate inorganic oxide support having an
average
particle size from 10 to 150 microns, a surface area greater than 100 m2/g and
a pore
volume greater than 0.3 ml./g with
(ii) an aqueous solution of Zr(SO4)2.4H20 and hydrates thereof to provide
not less
than 1 weight % based on the weight of the support of said salt;
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(iii) calcining said impregnated support at a temperature from 300 C to
600 C for a
time from 2 to 20 hours in an inert atmosphere;
(iv) and either
(a) contacting said calcined support with a hydrocarbyl solution containing
at
least 5 weight % of an aluminum activator compound of the formula
R122A10(R12A10),,A1R122 wherein each R12 is independently selected from the
group consisting of C1_20 hydrocarbyl radicals and q is from 3 to 50 to
provide
from 0.1 to 30 weight % of said aluminum compound based on the weight of said
calcined support;
optionally separating said activated support from said hydrocarbyl solution
and
contacting said activated support with a hydrocarbyl solution containing at
least 5
weight A of a single site catalyst as set out below or
(b) contacting said support with a hydrocarbyl solution containing at least
5
weight % of an aluminum activator compound of the formula
R122A10(R12A10),,A1R122 wherein each R12 is independently selected from the
group consisting of C1_20 hydrocarbyl radicals and q is from 3 to 50 and at
least 5
weight % of the above ketamide; and
(v) recovering and drying the catalyst.
A further embodiment comprises a disperse phase polymerization process
comprising contacting one or more C2_8 alpha olefins with a ketimide catalyst,
as
described above, which does not have any anti static on the support and
feeding to the
reactor from 10 to 80 ppm based on the weight of the polymer produced of an
antistatic
comprising:
(i) from 3 to 48 parts by weight of one or more polysulfones comprising:
(a) 50 mole % of sulphur dioxide;
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(b) 40 to 50 mole % of a C6-2o an alpha olefin; and
(c) from 0 to 10 mole % of a compound of the formula ACH=CHB where A is
selected from the group consisting of a carboxyl radical and a C1-15 carboxy
alkyl
radical and B is a hydrogen atom or a carboxyl radical provided if A and B are
carboxyl radicals A and B may form an anhydride;
(ii) from 3 to 48 parts by weight of one or more polymeric polyamines of
the formula:
RNRCH2CHOHCH2NR1)a-(CH2CHOHCH2NR1-R2-NH)b-(CH2CHOHCH2NR3)c-H]xH2-x
wherein R1 is an aliphatic hydrocarbyl group of 8 to 24 carbon atoms, R2 is an
alkylene
group of 2 to 6 carbon atoms, R3 is the group R2-HNR1; R is R1 or an N-
aliphatic
hydrocarbyl alkylene group having the formula R1NHR2, a, b and c are integers
from 0
to 20 and x is 1 or 2; with the proviso that when R is R1 then a is greater
than 2 and b =
c = 0 and when R is R1NHR2 then a is 0 and the sum of b+c is an integer from 2
to 20;
and
(iii) from 3 to 48 parts by weight of C10-20 alkyl or arylalkyl sulphonic
acid.
A further embodiment comprises a disperse phase polymerization process
comprising contacting one or more C2-8 alpha olefins with a ketimide catalyst,
as
described above, having an anti static agent on the support (or catalyst as
the case
may be).
Preferably the catalysts have an activity greater than 1350 g of polymer per
gram
of supported catalyst per hour normalized to 200 psig (1378 kPa) ethylene
partial
pressure and 90 C and having a kinetic profile for a plot of ethylene
consumption in
standard liters of ethylene per minute against time in minutes, at a reaction
pressure of
1379 kPag (200psig) and 90 C, corrected for the volume of ethylene in the
reactor prior
to the commencement of the reaction, in a 2 liter reactor over a period of
time from 0 to
60 minutes is such that the ratio of the maximum peak height over the first 10
minutes
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to the average ethylene consumption from 10 to 60 minutes taken at not less
than 40
data points, is less than 2.75.
BRIEF DESCRIPTION OF THE DRAWING
Figure 1 is the kinetic profile of the catalysts run in example 1.
DETAILED DESCRIPTION
As used in this specification dispersed phase polymerization means a
polymerization in which the polymer is dispersed in a fluid polymerization
medium. The
fluid may be liquid in which case the polymerization would be a slurry phase
polymerization or the fluid could be gaseous in which case the polymerization
would be
a gas phase polymerization, either fluidized bed or stirred bed.
As used in this specification kinetic profile means a plot of ethylene
consumption
in standard liters of ethylene per minute against time in minutes, corrected
for the
volume of ethylene in the reactor prior to the commencement of the reaction,
in a 2 liter
reactor over a period of time from 0 to 60 minutes.
As used in this specification gram of supported catalyst means a gram of the
catalyst and activator on the support treated with Zr(SO4)2.4H20.
The Support
The support for the catalysts of the present invention comprises a silica
oxide
substrate having a pendant reactive moiety. The reactive moiety may be a
siloxyl
radical but more typically is a hydroxyl radical. The support should have an
average
particle size from about 10 to 150 microns, preferably from about 20 to 100
microns.
The support should have a large surface area typically greater than about 100
m2/g,
preferably greater than about 250 m2/g, most preferably from 300 m2/g to 1,000
m2/g.
The support will be porous and will have a pore volume from about 0.3 to 5.0
ml/g,
typically from 0.5 to 3.0 ml/g.
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Silica suitable for use as a support in the present invention is amorphous.
For
example, some commercially available silicas are marketed under the trademark
of
Sylopol 958, 955 and 2408 by Davison Catalysts a Division of W. R. Grace and
Company and ES70 and ES7OW by Ineos Silica.
The resulting support is in the form of a free flowing dry powder.
Treatment of the Support
The support is treated with an aqueous solution of Zr(SO4)2.4H20. The support
need not be dried or calcined as it is contacted with an aqueous solution.
Generally a 2 to 50, typically a 5 to 15, preferably an 8 to 12, most
preferably a 9
to 11 weight % aqueous solution of Zr(SO4)2.4H20 is used to treat the support.
The
support is contacted with the solution of Zr(SO4)24H20 at a temperature from
10 C to
50 C, preferably from 20 to 30 C, for a time of not less than 30 minutes,
typically from 1
to 10 hours, preferably from 1 to 4 hours, until the support is thoroughly
impregnated
with the solution.
The impregnated support is then recovered typically by drying at an elevated
temperature from 100 C to 150 C, preferably from 120 C to 140 C, most
preferably
from 130 C to 140 C, for about 8 to 12 hours (e.g. overnight). Other recovery
methods
would be apparent to those skilled in the art.
The dried impregnated support is then calcined. It is important that the
support
be calcined prior to the initial reaction with an aluminum activator, catalyst
or both.
Generally, the support may be heated at a temperature of at least 200 C for up
to 24
hours, typically at a temperature from 500 C to 600 C, preferably from 550 C
to 600 C
for about 2 to 20, preferably 4 to 10 hours. The resulting support will be
free of
adsorbed water and should have a surface hydroxyl content from about 0.1 to 5
mmol/g
of support, preferably from 0.5 to 3 mmol/g of support.
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The amount of the hydroxyl groups in silica may be determined according to the
method disclosed by J. B. Pen i and A. L. Hensley, Jr., in J. Phys. Chem., 72
(8), 2926,
1968.
The Zr(SO4)2 is substantially unchanged by calcining.
The resulting dried and calcined support is then contacted sequentially with
the
activator and the catalyst in an inert hydrocarbon diluent
The Activator
The activator is an aluminoxane compound of the formula R122A10(R12A10)AIR122
wherein each R12 is independently selected from the group consisting of C1-20
hydrocarbyl radicals and q is from 3 to 50. In the aluminum activator
preferably R12 is a
C1-4 alkyl radical, preferably a methyl radical and q is from 10 to 40.
Optionally, a
hindered phenol may be used in conjunction with the aluminoxane to provide a
molar
ratio of Al:hindered phenol from 2:1 to 5:1 if the hindered phenol is present.
Generally,
the molar ratio of AI:hindered phenol, if it is present, is from 3.25:1 to
4.50:1. Preferably
the phenol is substituted in the 2, 4 and 6 position by a C2-6 alkyl radical.
Desirably the
hindered phenol is 2,6-di-tert-butyl-4-ethyl-phenol.
The aluminum compounds (aluminoxanes and optionally hindered phenol) are
typically used as activators in substantial molar excess compared to the
amount of
transition metal (e.g. group 4 transition metal) in the catalyst.
Aluminum:transition
metal (in the catalyst) molar ratios may range from 10:1 to 10,000:1,
preferably 10:1 to
500:1, most preferably from 50:1 to 150:1, especially from 90:1 to 120:1.
Typically the loading of the alminoxane compound may range from 0.05 up to 30
weight % preferably from 0.1 to 2 weight %, most preferably from 0.15 to 1.75
weight %
based on the weight of the calcined support impregnated with zirconium salt.
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The aluminoxane is added to the support in the form of a hydrocarbyl solution,
typically at a 5 to 30 weight % solution, preferably an 8 to 12 weight A)
solution, most
preferably a 9 to 10 weight % solution. Suitable hydrocarbon solvents include
C5-12
hydrocarbons which may be unsubstituted or substituted by 01-4 alkyl group
such as
pentane, hexane, heptane, octane, cyclohexane, methylcyclohexane, toluene, or
hydrogenated naphtha. An additional solvent is Isopar ETM (C8-12 aliphatic
solvent,
Exxon Chemical Co.).
The treated support may optionally be filtered and/or dried under an inert
atmosphere (e.g. N2) and optionally at reduced pressure, preferably at
temperatures
from room temperature up to about 80 C.
The optionally dried support with activator is then contacted with the complex
containing the ketimide ligand (catalyst) again in a hydrocarbyl solution as
noted above.
In an alternate embodiment the support could be treated with a combined
solution of activator and catalyst.
The Complex Containing the Ketimide Ligand (Catalyst)
The catalyst comprises an organo group 4 metal complex containing a ketimide
ligand. Preferably the group 4 metal has an atomic number not greater than 72.
The ketimide may have the formula:
Sub 1 Sub 2
\ /
wherein Sub 1 and Sub 2 are independently selected from the group consisting
of 01-20
hydrocarbyl radicals which are unsubstituted or may be substituted by up to 4
hetero
atoms selected from the group consisting of N,O, and S or up to three 01-9
straight
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chain, branched, cyclic or aromatic radicals which may be unsubstituted or
substituted
by a C1-6 alkyl radical or Sub 1 and Sub 2 taken together may form a saturated
or
unsaturated ring which may be unsubstituted or substituted by up to 4 hetero
atoms
selected from the group consisting of NO, and S and which ring may be further
substituted by up to three C1-9 straight chain, branched, cyclic or aromatic
radicals
which may be unsubstituted or substituted by one or more C1-6 alkyl radicals.
The complex containing the ketimide ligand may have the formula:
LmKn MY()
wherein M is a group 4 metal, most preferably Ti, having an atomic number not
greater
than 72 (e.g. less than or equal to 72), L is a monoanionic ligand selected
from the
group consisting of cyclopentadienyl-type ligands, K is a ketimide ligand, Y
is
independently selected from the group consisting of activatable ligands, m is
0 or 1, n is
1 or 2, o is an integer and the sum of m+n+o equals the valence state of M.
Preferred ketimide ligands have the formula
1
N N n
NC'
1/1
wherein each Rlis independently selected from the group consisting of a phenyl
radical
which is unsubstituted or substituted by up to three C1-4 alkyl radicals,
preferably
isoproyly radicals. A preferred ketimide is 1,3-bis(2,6-diisopropylpheny1)-1,3-
dihyd10-
2H-imidazol-2-ylideneamine.
The term "cyclopentadienyl" refers to a 5-member carbon ring having
delocalized
bonding within the ring and typically being bound to the active catalyst site,
generally a
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transition metal, preferably group 4, (M) through 15 - bonds. The
cyclopentadienyl
ligand may be unsubstituted or up to fully substituted with one or more
substituents
selected from the group consisting of C1_10 hydrocarbyl radicals which are
unsubstituted
or further substituted by one or more substituents selected from the group
consisting of
a halogen atom; a C1_4 alkyl radical; a halogen atom; a C1_8 alkoxy radical; a
C6_10 aryl
or aryloxy radical which is unsubstituted or may be up to fully substituted by
one or
more substituents selected from the group consisting of halogen atoms,
preferably
fluorine, C1-4 alkyl radicals and a phenyl or benzyl radical which is
unsubstituted or
substituted by one or more fluorine atoms; an amido radical which is
unsubstituted or
substituted by up to two C1_8 alkyl radicals; a phosphido radical which is
unsubstituted
or substituted by up to two C1_8 alkyl radicals; silyl radicals of the formula
-Si-(R)3
wherein each R is independently selected from the group consisting of
hydrogen, a C1-8
alkyl or alkoxy radical, C6_10 aryl or aryloxy radicals and germanyl radicals
of the formula
Ge-(R)3 wherein R is as defined above.
Preferably the cyclopentadienyl-type ligand is selected from the group
consisting
of a cyclopentadienyl radical, an indenyl radical and a fluorenyl radical
which radicals
are unsubstituted or up to fully substituted by one or more substituents
selected from
the group consisting of a fluorine atom, a chlorine atom, C1-4 alkyl radicals
and a phenyl
or benzyl radical which is unsubstituted or substituted by one or more
fluorine atoms.
Activatable ligands Y may be selected from the group consisting of a halogen
atom, Ci_4 alkyl radicals, C6_20 aryl radicals, C7-12 arylalkyl radicals,
C6_10 phenoxy
radicals, amido radicals which may be substituted by up to two C1_4 alkyl
radicals and
C1-4 alkoxy radicals. Preferably, Y is selected from the group consisting of a
chlorine
atom, a methyl radical, an ethyl radical and a benzyl radical.
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Suitable ketimide complexes (catalysts) are Group 4, preferably Ti,
organometallic complexes which contain one or two, preferably one, ketimide
ligands
(as described above) and one or zero, preferably one, cyclopentadienyl-type
(L) ligand
and two activatable ligands.
The loading of the catalyst on the support should be such to provide from
about
0.010 to 0.50, preferably from 0.015 to 0.40, most preferably from 0.015 to
0.035 mmol
of group IV metal (e.g. Ti) from the ketimide complex (catalyst) per gram of
support
(support treated with Zr(S042-4H20)) and calcined and treated with an
activator).
The ketimide complex (catalyst) may be added to the support in a hydrocarbyl
solvent such as those noted above. The concentration of ketimide complex
(catalyst) in
the solvent is not critical. Typically, it may be present in the solution in
an amount from
about 5 to 15 weight %.
The supported catalyst (e.g. support, Zr(SO4)2, activator and catalyst)
typically
has a reactivity in a dispersed phase reaction (e.g. gas or slurry phase) from
1350,
preferably greater than 1400, g of polyethylene per gram of supported catalyst
per hour
normalized to an ethylene partial pressure of 200 psig (1379 kPa) and a
temperature of
90 C.
The supported catalyst of the present invention may be used in dispersed phase
polymerizations in conjunction with a scavenger such as an aluminum alkyl of
the
formula Al(R30)3 wherein R3 is selected from the group consisting of C1_10
alkyl radicals,
preferably C2_4 alkyl radicals. The scavenger may be used in an amount to
provide a
molar ratio of Al:Ti from 20 to 2000, preferably from 50 to 1000, most
preferably
100:500. Generally, the scavenger is added to the reactor prior to the
catalyst and in
the absence of additional poisons over time declines to 0.
17
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The supported catalyst will have a kinetic profile for a plot of ethylene
consumption in standard liters of ethylene per minute against time in minutes,
corrected
for the volume of ethylene in the reactor prior to the commencement of the
reaction, in
a 2 liter reactor over a period of time from 0 to 60 minutes is such that the
ratio of the
maximum peak height over the first 10 minutes to the average ethylene
consumption
from 10 to 60 minutes taken at not less than 40, preferably greater than 60
most
preferably from 120 to 300 data points, is less than 2.75, preferably less
than 2, most
preferably less than 1.75.
The supported catalyst may be used in conjunction with an antistatic agent. In
one embodiment the antistatic is added directly to the supported catalyst. The
antistatic
may be added in an amount from 0 (e.g. optionally) up to 150,000 parts per
million
(ppm), preferably from 15,000 up to 120,000 ppm based on the weight of the
supported
catalyst.
In a further embodiment the antistatic may be added to the reactor in an
amount
from 0 to 100, preferably from 10 to 80 ppm based on the weight of the polymer
produced (i.e. the weight of polymer in the fluidized bed or the weight of
polymer
dispersed in the slurry phase reactor). If present, the antistatic agent may
be present in
an amount from about 0 to 100, preferably from about 10 to 80 most preferably
from 20
to 50 ppm based in the weight of polymer. From the productivity of the
catalyst it is
fairly routine to determine the feed rate of the antistatic to the reactor
based on the
catalyst feed rate.
Antistatic "Polysulfone" Additive
The antistatic polysulfone additive comprises at least one of the components
selected from:
(1) a polysulfone copolymer;
18
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(2) a polymeric polyamine; and
(3) an oil-soluble sulfonic acid, and, in addition, a solvent for the
polysulfone
copolymer.
Preferably, the antistatic additive comprises at least two components selected
from above components (1), (2) and (3). More preferably, the antistatic
additive
comprises a mixture of (1), (2) and (3).
According to the present invention, the polysulfone copolymer component of the
antistatic additive (often designated as olefin-sulfur dioxide copolymer,
olefin
polysulfones, or poly(olefin sulfone)) is a polymer, preferably a linear
polymer, wherein
the structure is considered to be that of alternating copolymers of the
olefins and sulfur
dioxide, having a one-to-one molar ratio of the comonomers with the olefins in
head to
tail arrangement. Preferably, the polysulfone copolymer consists essentially
of about
50 mole % of units of sulfur dioxide, about 40 to 50 mole A, of units derived
from one or
more 1-alkenes each having from about 6 to 24 carbon atoms and from about 0 to
10
mole percent of units derived from an olefinic compound having the formula
ACH=CHB
where A is a group having the formula ¨(Cr H2)¨COOH wherein x is from 0 to
about
17 and B is hydrogen or carboxyl, with the provision that when B is carboxyl,
x is 0 and
wherein A and B together can be a dicarboxylic anhydride group.
Preferably, the polysulfone copolymer employed in the present invention has a
weight average molecular weight in the range 10,000 to 1,500,000, preferably
in the
range 50,000 to 900,000. The units derived from the one or more 1-alkenes are
preferably derived from straight chain alkenes having 6-18 carbon atoms, for
example
1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-hexadecene and 1-
octadecene. Examples of units derived from the one or more compounds having
the
formula ACH=CHB are units derived from maleic acid, acrylic acid, 5-hexenoic
acid.
19
ZATrevor\TTSpec\2010013Can doc
A preferred polysulfone copolymer is 1-decene polysulfone having an inherent
viscosity (measured as a 0.5 weight percent solution in toluene at 30 C)
ranging from
about 0.04 dl/g to 1.6 dl/g.
The polymeric polyamines that can be suitably employed in the antistatic of
the
present invention are described in U.S. Patent 3,917,466, in particular at
column 6 line
42 to column 9 line 29.
The polyamine component in accordance with the present invention has the
general formula:
RNRCH2 CHOHCH2NR1)a-(CH2CHOHCH2NR1-R2-N H)b-(CH2C H OH CH2NR3)c-FI]xH2-x
wherein R1 is an aliphatic hydrocarbyl group of 8 to 24 carbon atoms, R2 is an
alkylene
group of 2 to 6 carbon atoms, R3 is the group R2-HNR1, R is R1 or an N-
aliphatic
hydrocarbyl alkylene group having the formula R1NHR2, a, b and c are integers
from 0
to 20 and x is 1 or 2; with the provision that when R is R1 then a is greater
than 2 and
b=c=0 and when R is R1NHR2then a is 0 and the sum of b+c is an integer from 2
to 20.
The polymeric polyamine may be prepared for example by heating an aliphatic
primary monoamine or N-aliphatic hydrocarbyl alkylene diamine with
epichlorohydrin in
the molar proportion of from 1:1 to 1:1.5 at a temperature of 50 C to 100 C in
the
presence of a solvent, (e.g. a mixture of xylene and isopropanol) adding a
strong base,
(e.g. sodium hydroxide) and continuing the heating at 50 to 100 C for about 2
hours.
The product containing the polymeric polyamine may then be separated by
decanting
and then flashing off the solvent.
The polymeric polyamine is preferably the product of reacting an N-aliphatic
hydrocarbyl alkylene diamine or an aliphatic primary amine containing at least
8 carbon
atoms and preferably at least 12 carbon atoms with epichlorohydrin. Examples
of such
aliphatic primary amines are those derived from tall oil, tallow, soy bean
oil, coconut oil
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and cotton seed oil. The polymeric polyamine derived from the reaction of
tallowamine
with epichlorohydrin is preferred. A method of preparing such a polyamine is
disclosed
in U.S. Patent 3,917,466, column 12, preparation B.1.0
The above-described reactions of epichlorohydrin with amines to form polymeric
products are well known and find extensive use in epoxide resin technology.
A preferred polymeric polyamine is a 1:1.5 mole ratio reaction product of N-
tallow-1,3-diaminopropane with epichlorohydrin. One such reaction product is
uPolyfloTM 130" sold by Universal Oil Company.
According to the present invention, the oil-soluble sulfonic acid component of
the
antistatic is preferably any oil-soluble sulfonic acid such as an
alkanesulfonic acid or an
alkylarylsulfonic acid. A useful sulfonic acid is petroleum sulfonic acid
resulting from
treating oils with sulfuric acid.
Preferred oil-soluble sulfonic acids are dodecylbenzenesulfonic acid and
dinonylnaphthylsulfonic acid.
The antistatic additive preferably comprises Ito 25 weight % of the
polysulfone
copolymer, 1 to 25 weight % of the polymeric polyamine, 1 to 25 weight % of
the oil-
soluble sulfonic acid and 25 to 95 weight % of a solvent. Neglecting the
solvent, the
antistatic additive preferably comprises about 5 to 70 weight % polysulfone
copolymer,
5 to 70 weight % polymeric polyamine and 5 to 70 weight % oil-soluble sulfonic
acid
and the total of these three components is preferably 100%.
Suitable solvents include aromatic, paraffin and cycloparaffin compounds. The
solvents are preferably selected from among benzene, toluene, xylene,
cyclohexane,
fuel oil, isobutane, kerosene and mixtures thereof.
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According to a preferred embodiment of the present invention, the total weight
of
components (1), (2), (3) and the solvent represents essentially 100% of the
weight of
the antistatic additive.
One useful composition, for example, consists of 13.3 weight % 1:1 copolymer
of
1-decene and sulfur dioxide having an inherent viscosity of 0.05 determined as
above,
13.3 weight % of "PolyfloTM 130" (1:1.5 mole ratio reaction product of N-
tallow-1,3-
diaminopropane with epichlorohydrin), 7.4 weight % of either
dodecylbenzylsulfonic
acid or dinonylnaphthylsulfonic acid, and 66 weight % of an aromatic solvent
which is
preferably toluene or kerosene.
Another useful composition, for example, consists of 2 to 7 weight % 1:1
copolymer of 1-decene and sulfur dioxide having an inherent viscosity of 0.05
determined as above, 2 to 7 weight % of "PolyfloTM 130" (1:1.5 mole ratio
reaction
product of N-tallow-1,3-diaminopropane with epichlorohydrin), 2 to 8 weight %
of either
dodecylbenzylsulfonic acid or dinonylnaphthylsulfonic acid, and 78 to 94
weight % of an
aromatic solvent which is preferably a mixture of 10 to 20 weight % toluene
and 62 to
77 weight % kerosene.
According to a preferred embodiment of the present invention, the antistatic
is a
material sold by Octel under the trade name STADISTm, preferably STADISTm 450,
more
preferably STADISTm 425.
Gas Phase Polymerization
Fluidized bed gas phase reactors to make polyethylene are generally operated
at low temperatures from about 50 C up to about 120 C (provided the sticking
temperature of the polymer is not exceeded) preferably from about 75 C to
about
110 C and at pressures typically not exceeding 3,447 kPa (about 500 psi)
preferably
not greater than about 2,414 kPa (about 350 psi).
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Gas phase polymerization of olefins is well known. Typically, in the gas phase
polymerization of olefins (such as ethylene) a gaseous feed stream comprising
of at
least about 80 weight % ethylene and the balance one or more C3_6
copolymerizable
monomers typically, 1-butene, or 1-hexene or both, together with a ballast gas
such as
nitrogen, optionally a small amount of C1-2 alkanes (i.e. methane and ethane)
and
further optionally a molecular weight control agent (typically hydrogen) is
fed to a
reactor and in some cases a condensable hydrocarbon (e.g. a C4_6 alkane such
as
pentane). Typically, the feed stream passes through a distributor plate at the
bottom of
the reactor and vertically traverses a bed of polymer particles with active
catalyst,
typically a fluidized bed but the present invention also contemplates a
stirred bed
reactor. A small proportion of the olefin monomers in the feed stream react
with the
catalyst. The unreacted monomer and the other non-polymerizable components in
the
feed stream exit the bed and typically enter a disengagement zone where the
velocity
of the feed stream is reduced so that entrained polymer falls back into the
fluidized bed.
Typically the gaseous stream leaving the top of the reactor is then passed
through a
compressor. The compressed gas is then cooled by passage through a heat
exchanger to remove the heat of reaction. The heat exchanger may be operated
at
temperatures below about 65 C, preferably at temperatures from 20 C to 50 C.
If there
is a condensable gas it is usually condensed and entrained in the recycle
stream to
remove heat of reaction by vaporization as it recycles through the fluidized
bed.
Polymer is removed from the reactor through a series of vessels in which
monomer is separated from the off gases. The polymer is recovered and further
processed. The off gases are fed to a monomer recovery unit. The monomer
recovery
unit may be selected from those known in the art including a distillation
tower (i.e. a C2
splitter), a pressure swing adsorption unit and a membrane separation device.
23
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Ethylene and hydrogen gas recovered from the monomer recovery unit are fed
back to
the reactor. Finally, make up feed stream is added to the reactor below the
distributor
plate.
Slurry Polymerization
Slurry processes are conducted in the presence of a hydrocarbon diluent such
as an alkane (including isoalkanes), an aromatic or a cycloalkane. The diluent
may
also be the alpha olefin comonomer used in copolymerizations. Preferred alkane
diluents include propane, butanes, (i.e. normal butane and/or isobutane),
pentanes,
hexanes, heptanes and octanes. The monomers may be soluble in (or miscible
with)
the diluent, but the polymer is not (under polymerization conditions). The
polymerization temperature is preferably from about 5 C to about 200 C, most
preferably less than about 110 C typically from about 10 C to 80 C. The
reaction
temperature is selected so that the ethylene copolymer is produced in the form
of solid
particles. The reaction pressure is influenced by the choice of diluent and
reaction
temperature. For example, pressures may range from 15 to 45 atmospheres (about
220 to 660 psi or about 1500 to about 4600 kPa) when isobutane is used as
diluent
(see, for example, U.S. patent 4,325,849) to approximately twice that (i.e.
from 30 to 90
atmospheres ¨ about 440 to 1300 psi or about 3000 -9100 kPa) when propane is
used
(see U.S.patent 5,684,097). The pressure in a slurry process must be kept
sufficiently
high to keep at least part of the ethylene monomer in the liquid phase.
The reaction typically takes place in a jacketed closed loop reactor having an
internal stirrer (e.g. an impeller) and at least one settling leg. Catalyst,
monomers and
diluents are fed to the reactor as liquids or suspensions. The slurry
circulates through
the reactor and the jacket is used to control the temperature of the reactor.
Through a
series of let down valves the slurry enters a settling leg and then is let
down in pressure
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to flash the diluent and unreacted monomers and recover the polymer generally
in a
cyclone. The diluent and unreacted monomers are recovered and recycled back to
the
reactor.
The Polymer
The resulting polymer may have a density from about 0.915 g/cc to about 0.960
g/cc. The resulting polymers may be used in a number of applications such as
extrusion, and both injection and rotomolding applications. Typically the
polymer may
be compounded with the usual additives including heat and light stabilizers
such as
hindered phenols; ultra violet light stabilizers such as hindered amine
stabilizers
(HALS); process aids such as fatty acids or their derivatives and
fluoropolymers
optionally in conjunction with low molecular weight esters of polyethylene
glycol.
EXAMPLES
The present invention will now be illustrated by the following non limiting
examples.
Experimental Procedure
The catalyst used in all experiments was a titanium (IV) complex having one
Cp ¨ C6F5 ligand, two chloride ligands and one ketimide ligand [C6F5Cp][1,3-
bis(2,6-
diisopropylpheny1)-1,3-dihydro-2H-imidazol-2-iminato]TiC12.
General Synthetic Methods
All reactions involving air and or moisture sensitive compounds were conducted
under nitrogen using standard Schlenk or cannula techniques, or in a glovebox.
Reaction solvents were purified either using the system described by Pangborn
et al. in
Organometallics, 1996, v/5, p.1518 (toluene, heptanes) or distilled and stored
over
activated 4 A sieves (tetrahydrofuran (THF)). Hexafluorobenzene was purchased
from
Aldrich and stored over 4A sieves in a glovebox. The following materials were
ZATrevor\TTSpec\2010013Can.doc
CA 02708013 2010-06-18
purchased from Aldrich and stored in an Innovative Technologirm glove box:
KOtBu,
BuLi, NaCp, 1,2-Bis(2,6-Diisopropylphenylimino)ethane and TiCI4.
Trimethylsilylazide
(TMSN3) was purchased from Aldrich and used without further purification.
Zr(SO4)2=4H20 (99.99+ /0) was used as received from Strem Chemicals.
Deuterated
solvents were purchased from Aldrich (toluene-d8, THF-d8) and were stored over
4A
sieves. NMR spectra were recorded using Bruker spectrometers (200, 300, 400
MHz
for 1H, 75.42 MHz for 13C, 121.42 MHz for 31P, 282.4 for 19F).
Molecule Preparation
1 ,3-bis(2,6-diisopropylpheny1)-1,3-dihydro-2H-imidazol-2-ylidene: This
compound was prepared according to a published procedure of L. Jajapour,
E.D.Stevens and S.P. Nolan J. Organometallic Chem 2000,606, 49-54.
H NMR (toluene-d8, 8): 7.34-7.21 (m, 2H), 7.21-7.12 (m 4H), 6.65 (s, 2H), 3.06-
2.81
(sept., 4H) and 1.38-1.1 (2d, 24H).
[1,3-bis(2,6-diisopropylpheny1)-1,3-dihydro-2H-imidazol-2-
iminatoprimethylsilane: Solid 1,3-bis(2,6-diisopropylphenyI)-1,3-dihydro-2H-
imidazol-
2-ylidene was dissolved in 20m1 of toluene. To this solution was added batch-
wise
excess TMSN3 (5.0m1, 38.0 mmol) as the solution was being heated to reflux.
After all
TMSN3 was added the solution was refluxed at 125 C for 5 hours. All volatiles
were
pumped off leaving a yellow solid which was slurried in 20m1 of toluene and
hot (60 C)
filtered. All toluene was pumped off leaving the product as a yellow solid,
4.9g (83%).
1H NMR (toluene-d8, 6): 7.32-7.04 (m, 6H), 5.96 (s, 2H), 3.28-3.01 (sep., 4H),
1.42-1.30
(d, 12H), 1.23-1.12 (d, 12H) and ¨0.24 (s, 9H).
[C6F5-Cp]TMS: To a Schlenk flask containing NaCp (2.0 M in THF, 160.0 mL,
320.0 mmol) was added a solution of hexafluorobenzene (29.8 g, 160.0 mmol) in
50 mL
THF drop wise over 15 minutes. The purple solution was heated to 60 C for 3
hours.
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CISiMe3 (30.0mL, 225.0 mmol) was added via a dropping funnel over a period of
30
minutes, then stirred under nitrogen overnight. The volatiles were removed in
vacuo,
the solid was triturated 2 times with heptanes, filtered, and then washed with
heptanes
(5 x 10 mL). Heptanes were removed in vacuo yielding a brown/purple liquid,
which
was then distilled under full vacuum at 95 C. A clear, colorless liquid was
obtained
(21.8 g, 45%; 89% pure by GC/MS: M+ = 304 at 21.7 min).
Li(C6F8-CpTMS): BuLi (1.6 M in hexane, 49.4 mL, 79.0 mmol) was added to a
solution of [C8F8CpTMS] (22.8 g, 75.0 mmol) in heptanes (300 mL) via a
dropping
funnel at room temperature over a period of 40 minutes. The reaction was
stirred for 3
days, filtered and the resulting white solid was washed with heptanes (3 x 5
mL) and
isolated in vacuo (18.5 g, 60%). 1H NMR (THF-d8): 8 6.46 (m, 1H, CpH), 6.35
(m, 1H,
CpH), 5.96 (m, 1H, CpH), 0.14 (s, 9H, S1CH3). 19F NMR (THF-d8): 8 -145.8 (m,
2F), -
168.6 (m, 2F), -172.7 (m, 1F).
[C8F8Cp]TiC13: [C8F5)CIDIrMS (65.1 g, 214.0 mmol) was added drop-wise over
20 minutes to neat titanium tetrachloride (49.1, 258.0 mmol) while stirring at
60 C. A
dark red-brown solution resulted, which was subsequently stirred for 3 hours
at 60 C.
Heptane (100 mL) was then added to give a slurry, which was cooled by removing
solvent under vacuum to half the initial volume. The solid product was
isolated by
filtration, washed with additional heptane and dried under vacuum to give an
orange-
brown solid (57.4 g, 70%). 1H NMR (toluene-d8): 8 6.67 (m, 2H), 6.09 (m, 2H).
19F
NMR (toluene-d8): 8 -139.6 (m, 2F), -152.7 (t, J= 3.8 Hz, 1F), -163.0 (m, 2F).
[C6F5Cp][1,3-bis(2,6-diisopropylpheny1)-1,3-dihydro-2H-imidazol-2-
iminatorTiC12: To a toluene solution of [C8F8Cp]TiCI3 (0.2g, 0.4 mmol) was
added [1,3-
bis(2,6-diisopropylpheny1)-1,3-dihydro-2H-imidazol-2-iminato]trimethylsilane
(0.2g,
0.4mmol) at -40 C. The solution was then stirred for 16 hours while warming to
room
27
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temperature. All toluene was pumped off and the solid washed with pentane. The
complex was precipitated from toluene:pentane (5:45m1), filtered and dried to
give the
product as a yellow solid, 0.2 g (64%). 1H NMR (toluene-d8, 8): 7.35-6.88 (m,
6H),
6.65-6.47 (m, 2H), 5.81 (s, 2H), 5.72-5.65 (m, 2H), 3.03-2.76 (sep., 4H), 1.50-
1.36 (d,
12H) and 1.12-0.99 (d, 12H).
The aluminoxane was a 10% MAO solution in toluene supplied by Albemarle.
The support was silica SYLOPOL 2408 obtained from W.R. Grace.
Preparation of the Support (apart from the control)
A 10 % aqueous solution of the Zr(SO4)4H20 was prepared and impregnated
into the support by incipient wetness impregnation procedure. The solid
support was
dried in air at about 135 C to produce a free flowing powder. The resulting
powder was
subsequently dried in air at 200 C for about 2 hours under air and then under
nitrogen
at 600 C for 6 hours.
NAA Characterization: A sample of Zr(SO4)2 treated SLYOPOL 2408 prepared
as above was determined to have a sulfur:zirconium ratio of 0.703 by NAA
analysis,
which is consistent with the ratio expected for pure Zr(SO4)2.
XRD Analysis: A 1 gram sample of pure Zr(SO4)2 4H20 was dehydrated in a
muffle furnance at 600 C for 6 hours and the solid was analyzed by XRD
analysis,
which showed 100% of the Zr(SO4)2 remained.
The above shows that zirconia is not formed by the calcination process of
Zr(SO4)2.4H20 at up to 600 C under nitrogen.
To a slurry of calcined support in toluene was added a toluene solution of 10
wt% MAO (4.5 wt% Al, purchased from Albemarle) plus rinsings (3 x 5 mL). The
resultant slurry was mixed using a shaker for 1 hour at ambient temperature.
The slurry
was filtered, rinsed with toluene, pentane (2x), and dried to 400mTorr. To a
slurry of
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MAO-on-support is added a toluene solution of catalyst to give a molar ratio
of Al:Ti of
120:1. After two hours of mixing at room temperature using a shaker, the
slurry was
filtered, yielding a colorless filtrate. The solid component was washed with
toluene, and
pentane (2x), then ¨ 400 nnTorr and sealed under nitrogen until use.
Polymerization
A 2L reactor fitted with a stirrer (-650 rpm ) containing a NaCI seed bed
(160g)
(stored for at least 3 days at 130 C) was conditioned for 30 minutes at 105 C.
An
injection tube loaded in the glovebox containing the catalyst formulation was
inserted
into the reactor system, which was then purged 3 times with nitrogen and once
with
ethylene at 200 psi. Pressure and temperature were reduced in the reactor
(below 2
psi and between 60 and 85 C) and TIBAL (500:1 Al:Ti) was injected via gastight
syringe
followed by a 2 mL precharge of 1-hexene. After the reactor reached 85 C the
catalyst
was injected via ethylene pressure and the reactor was pressurized to 200 psi
total
pressure with 1-hexene fed with a syringe pump at a mole ratio of 6.5% C6/C2
started 1
minute after catalyst injection. The temperature of reaction was controlled at
90 C for a
total runtime of 60 minutes. Reaction was halted by stopping the ethylene flow
and
turning on reactor cooling water. The reactor was vented slowly to minimize
loss of
contents and the polymer / salt mixture was removed and allowed to air dry
before
being weighed. The results of the experiments are set forth in Table 1 below.
TABLE 1
Support AL:Ti Productivity Max Time Rate of Max height
Molar gPE/g C2 to Rise 1-10 /Average
ratio catalyst Flow Max scLM/min C2 concentration
Flow
SYLOPOL 120:1 1467 1.16 3.02 0.38 1.73
2408 ¨
Zr(SO4)2
SYLOPOL 120:1 1313 1.64 4.56 0.36 2.99
2408
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The results show an increased productivity of the catalyst on the support
treated
with Zr(SO4)2.4H20. The ratio of maximum peak height in the first 10 minutes
to the
average peak height for 10 to 60 minutes for the treated support was lower.
There is a
lower "light off' temperature even though it may have occurred earlier.
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