Note: Descriptions are shown in the official language in which they were submitted.
WO 93/23162 2 1 3 ~ O 1 PCr/US93/04385
OLEFIN POLYME:RIZATION CATALYST SYSTEM
.
The present invention is directed to an ole~-in
polymerization catalyst system based upon a member of
the class of conventional titanium trichloride
catalysts, in association with a novel cocatalyst based
upon an aluminum trialkyl and a silane component as
further des~ribed herein. The cocatalyst provides
isotactic ole~in polymers with higher catalytic activity
than catalyst systems of the prior art.
One of the earliest classes o~ Ziegler-Natta
catalyst systems developed for use in the polymerization
of olef~ins, especially alpha-olefins such as ethylene
and propylene, were catalyst systems that include
titanium and aluminum in the form of titanium trihalide
catalysts and orga~oaluminum compounds as cocatalysts.
The relatively simple nature of these systems provided a
compelling case for their use compared to more complex
so-called 'high activity' Ziegler-Natta solid catalyst
components which include titani~m ~IV) and magnesium.
The polymerization of propylene among other
stereochemical monomers concerns itself with the
structural ordering of the resulting polymer. The most
desirable polymers for industrial use are isotactic,
those where i~ recurring triads,:the depending methyl
groups are-o~ the same side of the molecule, affording
long term order and hence properties related to
developed~crystallinity.
Naturally, it was and is important -- --
commercially to secure such highly isotactic polymers in
high yield, and therefore one sought catalysts of high
activity as measured by weight of polymer per unit
weight of catalyst, and to control other polymerization~ -
parameters to direct morphology of the resulting polym~
, . . .
W093/23162 2 1 3 5 4 0 1 PCT/USg~/04385
--2--
to afford other~desirable properties such as high
crystalline melting point, and high bulk density.
Unfortuna~ely, the use of aluminum trialkyl
cocatalysts with titanium trichloride catalysts never
provided commercially useful polymers. It was
discovered, however, that dialkyl aluminum halides were
effective and these cocatalysts have been used nearly
exclusively in industry. No satisfactory substitute had
heretofore been found despite considerable interest and
economic motiva~ion. It became generally recogniæed in
the art that while aluminum alkyls such as triethyl
aluminum could usefully be employed as cocatalysts for
titanium (IV) catalysts they were unuseable on a
commercial scale for titanium (III) polymerizations.
It was, therefore, highly surprising t~ `
discover that an aluminum alkyl used coordinately with a
silane modifier as described was not only e~fective in a
titanium (III3 polymerization to provide polymer in high
yield, but would produce stereoregular polypropylene of
high isotacticity and other desirable properties such as
high crystalline meltin~ point and high bulk density.
This convenient, homogeneous catalyst system,
commercially effective in slurry ~olymeriæations, also
finds similar adv ntage in the gas phas~ polymerization
of propylene.. Thus, in optimized systems, polypropylene
of greater than 95 to 97% heptane inso~u~les can be
sustainably produced at an activity in excess of 6000- ¦
~000 lb/lb catalyst with a crystalline melting point of
~t least 160 to 16S~ and bul~ densities in excess of
24.
As noted above, such cocatalyst systems have
been used heretofore in connection-w-it~~-titanium (IV)
WO93/23162 2 1 ~ 5 4 0 1 PCT/~S93/04385
catalysts. And where polymers for ilm-making were to
be prepared other researchers have utilized such systems
as, for example, co~round TiCl3.AA and phosphine oxide
with added alkoxysilane in conjunction with an aluminum
alkyl, with some success, although thé resulting polymer
is of lower crystallinity so to reduce haze in the film.
The phosphine oxide is contraindicated in any event
insofar as its donative potential is somewhat too great
for successful mediation of the cataly~ic process, and
it is less acceptable in the sense of ecological
concerns.
The more typical disc~osures involving the use
of si-anes as cocatalyst components for titanium ~III)
polymerization, with or without an internal election
donor, uniformly utilize as cocatalyst the conventional
diethyl aluminum chloride.
In experimenting with systems employing a
ti~anium (I~I) catalyst component including an
~internal) electron donor, it has also been found by the
present inventor that the characteristics, particularly
the donative potential of shareable electrons provîded
by~the electron donor can p~ay a key role in providing
polymers of ~esirable characteri~stics for commercial
applications. ~
~ ~ In genera~, the selected elec~ron donor will
exhibit an ultraviolet absorption wavelength of less ~ ~ - - -
than about 250 nanometers, re}lective of the strength of : ~~ -~
electron bonding and hence the relative ease of donative
coordination. The lower wavelengths are associated with
more strongly bound electron pairs and thus evidence --
more moderate donative potential.
_
213~
W~93/23162 PCT/US93/04385
--4--
While not wishing t~ be bound by an
essentially hypothetical elucidation of the invention,
it is believed that the coordinate use of a selected
internal donor, and the trialkyl aluminumlalkoxysilane
cocatalysts, moderates and modulates the oxidation
reduction reaction in polymerization so as to maintain
and stabilize in a relative steady state the active form
of the Til 3 catalyst, preventing o~erreduction of the
active species while directing and ordering the
production of the desired isotactic product in the case
of propylene. In the case o~ use of the donor at the
preparative stage for the titanium component, the
internal donor is believed as well to assist in the
forming of the desired ~ or ~ crystalline form of the
TiCl 3 component.
In accordance with the present invention a
catalyst system is provided which comprises, as a
catalyst, a titanium (III) containing component, such as
TiX3.rMXlm, where X and Xl are the same or different and
are halogen; M is a metal of Group III of the Periodic
Table of the Elements; m is an integer of 3; and r is 0
to 0.7.
The titanium.~III) component is associated
.
with a selected electron donor of moderate donative
potential, preferably an ether or an ester. Pre~erably,
in the titanium (III) catalyst om~onent-X and Xl are
chlorine; and M is aluminum. More preferably, r is ~ to
0.33.
The cocatalyst component comprises a trialkyl
aluminum compound modified with-a- silane compound having
the structural formula (oRl)4~ SiR2DR3q, where Rl is
hydrocarbyl; and R2 and R3 are~-th~-same or different and
'I
W O 93/23162 2 1 3 5 1 ~ 1 P ~ ~US93/04385
--5--
~re hydrocarbyl; p is 0 or an int~-er o~ 1 or 2; and q
is an integer of 1 to 3, with the proviso that the sum
o~ p and q does not exceed 3.
Preferably, the trialkylaluminum compound
which functions as a cocatalyst has the structural
formula
AlR3
where R is C1 to C6 alkyl. More.preferably, in this
componen~ R is Cl to C4 a-lkyl- Most preferably, this
component is triethy1aluminum.
The TiC13 or TiCl3.AA co~ponent is associated
with an electron donor, preferably an organic ether or
ester. This ~itanium (III) component may comprise as
prepared the electron donor, as described, for example
in U.S. Patent Nos. 4,060,593 or 4,115,533 incorporated
herein by reference. Thus, titanium tetrachloride may
be reduced in situ, for example, with an aIuminum alkyl,
reacted with an electron donor and activated with
titanium tetrachloride to form the active TiCl3
component, pre~erably in the ~ or ~ form.
-In this embodiment, the preferred electron
donor is an organic ether such as a di-alkyl ether,
preferably C6 - C 2 alkyl, and most preferably di-
isoamyl ether,; di-n-octyl ether or di-n-dodecyl ether.
Obviously, other readily associable electron donors may
b~ utilized-to equivalent effect~ The electron donor is
employe~-~n an amount of 0.1 to 0.4 mm/mol TiC13,
preferably 0.2 to 0.3 mm/mol TiCl3.
Alternatively, the source of titanium (III)
may~be free of an electron donor, for example, it may be
a-coground TiCl3/AlCl3 as is known and available in the
art~.l In su~h case, the titanium (III) containing
213~01
WO93/23162 PCT/US93/04385
--6--
component is associated with an electron donor prior to
use. In this embodiment, the preferred electron donor
is an organic ester such as a compound having the
structural formula
R4 ~
where R4 is hydrogen, Cl to C4 alkyl or Cl to C4 alkoxy;
Rs is C to C 4 alkyl; and n is 0 or an integer of l to
3. ~his electron donor component, more preferably, is a
compound where R4 is hydrogen; R5 is C2 to C4 alkyl; and
n is l. Most preferably, this component is ~utyl
benzoate.
In this embodiment the molar ratio of the
titanium component to ester is in the range of between
about l:l and about 20:1. More preferably, this molar
ratio is in the range of between about 3:l and about
6:1.
In this embodimentl the electron donor
component is preferably introduced into the catalyst
system by being intimately blended together with the
titanium (III3 component. Preferably, this intimate
blending is provided by milling or simple mixing. More
prefera~ly, this blending is accomplished by milling,
especially by ballmilling.
The silane compound, useful as a cocatalyst
modifier h~s the structural formula
(OR~ p_~SiR2 R3
where Rl is hydrocarbyl; R2 and R3 are the same or
different and are hydrocarbyl; p is 0 or an integer of l
or 2; and ~ is an integer of l to 3, with the proviso
that the sum of p and q does not exceed 3.
WO93/23162 2 1 3 5 1 0 1 PCT/US93/04385
Prefer~bly, in this cocatalyst component Rl is alkyl;
and RZ and R3 are the same or different and are alkyl or
cycloalkyl. More preferably, this component is a silane
compound where Rl is C to C6 alkyl; and R2 and R3 are
the same or different and are cl to c6 alkyl or
cycloalkyl.
Still more preferably Rl is Cl to Ca alkyl;
and R2 and R3 are the same or different and are C -C6
alkyl or cycloalkyl. Even still more prefer~bly, p is 0
or l; and q is 1.
Typically, the silane cocatalyst modifier is
one or more o~ isobutyltrimethoxysilane,
isobutylisopropyldimethoxysil~ne,
diisopropyldimethoxysilane,
cyclohexylmethyldimethoxysilane or
dicyclopentyldimethoxysilane- i
Most preferably, the second catalyst component is
isobutylisopropyldimethoxysilane or
diisopropyldimethoxy- silane.
The components of the catalyst system are
presen~ in concentrations such that the molar ratio of
the titanium~ containing compound to the silane
compound i-s in the range of between about 1:0.2 and
about 1-1.2. Preferably, this molar ratio is in the
range of between about 1:0.4 and about 1:1.1. Still
more preferably,--this molar ratio is in the range of
between about ~:~.S- and about l:0.9.
The molar ratio of the trialkylaluminum
compound, to the silane compound, is in the range of
between abaut S:l and about 20:1. Prefera~ly, this
molar ratio is in the range of between abo r 7 :1 and
about 15~ - Still more preferably, the molar ratio of
213S~Ol
W093~23162 PCT/US93/04385
--8--
the trialkylaluminum component to the silane compound is
in the range of between ~bout 8:1 and about 12:1.
The present invention is also directed to a
process for polymerizing an olefin, generally in slurry
or gas phase. In this process an olefin is polymerized
under olefinic polymerization conditions in the presence
of the catalyst system of the subject invention.
Olefinic polymerization conditions are preferably those
that involve conducting the polymerization reaction at a
temperature in the range of between about 20C and about
150C and at a pressure in the range of between about
atmospheric and about 2,000 pounds per square inch gauge
(psig).
Preferably, the process of polymerizing an
olefin is directed to alpha-olefins which are
polymerized in the presence of a catalyst system within
the scope of the present invention under alpha-olefin
polymerization conditions which include a temperature in
the range of between about 40C and about 110C and a
pressure in the range of between about 100 psig and
about 1000 psig.
More preferably, the process of this invention
is directed to the polymerization of an alpha-olefin
having 2 to 8 carbon atoms under alpha-olefin
polymerization conditions which include a polymerization
reaction temperature in the range of between about 50C
and about 100C and a polymerization'reaction pressure
of between about 200 psig and about 800 psig.
~ Still more preferably, the process of this
invention involves the polymerization of an alpha-olefin
having 2 to,6 carbon atoms under alpha-olefin
po1ymerization condieions comprising a temperature of
WO93/23162 2 1 3 5 '1 0 1 PCT/~S93/04385
_g_
between a~out 60C and about 92C and a pressure in the
range of between about 300 psig and about 600 psig.
Even still more preferably, the process of the
subject invention concerns the polymerization of an
alpha-olefin selected from the group consisting of
ethylene and propylene under alpha-olefin polymerization
conditions comprising a temperature in the range between
about 62C and about 80C and a pressure in the range of
between about 3S0 psig and about 550 psig.
Most preferably, the process of the present
invention is directed to the polymerization of propylene
under propylene polymerization conditions which involve
a reaction at a temperature in the range of between
about 6~C and about 90C and at a pressure in the range
between about 400 psig and about 500 psig.
In a preferred embodiment of the process of
the present invention, the polymerization of an olefin
utilizing the catalyst system of this invention,
hy~rogen may optionally be provided thereto.
In the~preferred embodiment where the
polymerization occurs in the liquid phase the reaction
occurs in a so-called liquid pool wherein the only
diluent is the olefin polymerized, prefera~ly propylene.
In the pref rred embodiment where the polymerization
reaction occurs in the gas phase, the reaction occurs in
a stationary-.flui~ zed ~ed or a stirred bed. The
polymerization may-a-~so be conducted in cascaded
reactors, i.e., reactors whether for suspension, gas
phase or high pressure polymerization, are linked
func~ionally or ln practice such that the polymerization
product of the first reactor is ~urther reacted, usually
under diff.ë~e-.nt conditions, in a second reactor to
~ ,,
WO93/23162 2 1 ~ 5 ~ O 1 PCT/US93/04385
-10--
secure a compatibilited product of diverse
characteristics.
In the first embodiment aforementioned in
which an electron donor, preferably an ether is reacted
with the catalyst in a preparative stage an aluminum
alkyl or alkyl halide component is employed as a
reductant; in consequence this component may have some
catalyst reactivi~y before it is associated with the
TEAL~silane cocatalyst component of this invention.
This can be inconvenient for catalyst feed systems
utilizing polymerizablé monomer carrier such as is
commonly the case in gas phase operations. Accordingly,
in such instances it is typical to deactivate for
example any residual aluminum chloride, which can
conveniently be accomplished by reaction with butyl
benzoate. The resulting coordination cocatalyst then
relies solely upon the TEALlsilane system for cocatalyst
function.
A particular advantage of the present
cocatalyst resides in its capacity to f~nction
ef ectively both with the titanium (III) catalysts and
titanium (IV) catalysts, such that the respective
catalysts used conjointly in a single reactor may be
commonly cocatalyzed so to prepa~e polymer product of
diverse characteristics, e.g., different molecular
weight. These characteristics may then be controllably
altered by suitable selection of catalyst ratio having
regard for the individual characteristics such as
activity levels, or stereoregulating capacity, etc. In
consequence, the invention is understood to relate as
well to catalyst systems which include, in the broadest
sense, transition metal tIlI) and (IV) combinations
W O 93/23162 2 ~ 3 5 ~ ~ 1 PC~r/~S93/04385
which are then conunonly cocatalyzed with the disclosed
TEAL/silane components.
- I
=_=- ,
1,
W093/~3162 213~101
-12- PCT/US93/04385
EXAMPLE 1
A catalyst system was prepared by combining
titanium trichloride (0.04 g.),(itself prepared
according to the protocol of Example 4 of U.S. Patent
No. 4,115,~33) isobutylisopropyldimethoxy-silane (I~IP)
and triethylaluminum (TEAL) in a concentration such that
the molar ratio of these components was ~.0:0.5:4.6,
respectively. This catalyst system was introduced into
a reactor free of air and water.
The reactor into which the catalyst system was
introduced was next charged with hydrogen gas (500 ml.)
and liquid propylene (325 g., 650 ml~). The
polymerization reaction was thereupon initiated by
heating and pressurizing the reactor to a temperature of
70C and a pressure of 460 psiy. Concurrently wîth this
heating and pressurizing step the s~irrer, with which
the reactor was eguipped, was a~tivated. The stirrer
rotated at 400 revolutions per minute. The
polymerization reaction, operated under these
conditions, was continued for 1 hour. The reaction was
terminated after 1 hour by venting the excess propylene.
After the one hour propylene polymerization,
the polypropylene product of the polymeri~ation reaction
was weighed and analyzed. The polymer analysis
constituted the determination of the coneentration
therein o~ titanium, a measure of undesira~le catalyst
incorporation therein, by quantitative analysis well
known in the art. In addition, a determination of
percent heptane insol~bility of the po~ymex, a
measurement.of polypropy~ene isotacticity, was also
conducted.
WO93/23162 -13- 2 ~ ~ 5 ~ ~ 1 PCT/~S93/0438~
The po~ypropylene percent heptane insolubility
was determined in a procedure wherein a finely graund
sample (20 mesh) of the polypropylene obtained in the
above discussed polymerization reaction was heated at
100C for 30 minutes in a vacuum oven. The heated
sample, disposed in a tare container, i.e., a thimble,
was then carefully weighed. The ground polymer,
disposed in the thimble was thereupon disposed in an
extraction flask already filled with approximately 150
ml. of n-heptane. The n-heptane was heated to boiling
and refluxed, with the polypropylene sample disposed
therein, for 90 minutes. After 9~ minutes, reflexing
ceased and the thimble containing the polypxopylene
sample was removed.
The thimble containing the polypropylene
sample was rinsed in acetone after which it was again -
heat~d in the same vacuum oven, at 100C for 30 minutes.
The polypropylene sample, still in its tare container,
was cooled to ambient temperature and again weighted.
- Percent heptane insolubility was determined as
the ratio of the difference in net weight of the
pol~propylene before and after contact with boiling n-
hc:~tane for 90 minutes to the net polypropylene weight
p~ior to such contact.
Another polymer property analyzed was melt
flow rate, determined in accordance with A5TM Test
Procedure ~ ~~
D-1238. Finally, the polypropylene was tested to
determine its bulk density, in pounds per cubic foot,
which was obtained by taring a vessel of known volume
and weighing the vessel of known volume filled with the
WO93/23162 2 1 3 ~ ~ O 1 PCT/US93/04385
-14-
polypropylene produced in the above-discussed
polymerization.
The activity of the catalyst, in terms of
polypropylene weight per unit weight of catalyst, was
determined by weighing the polypropylene generated
during the 1 hour polymerization run and dividing that
number by the weight of catalyst charged into ~he
reactor.
The results of this example are summarized in
the Table which follows the last example.
, _
I
2135 101
W~g3/23162 PCT/~S93/043~5
--1 5--
EXAMPLE 2
Example 1 was identically reproduced but for
the composition of the cat~lyst. In Example 2 the molar
ratio of titanium trichloride, to
isobutylisopropyldimethoxysilane, to triethylaluminum,
was 1:0.7:6Ø Again titanium trichloride, was present
in an amount of 0.04 g.
The results of this example are summarized in
the Table.
2135 101
WO93/~3162 PCT/US93/0438
-16-
- EXAMPLE 3
Example l was identically reprod~ced again but
for the composition but for ~he relative amounts of the
catalyst components of the catalyst system. In Example
3 the molar ratio of titanium trichloride to
isobutylisopropyldimethoxy-silane ~o triethylaluminum
was l:0.9:7.5. Again, the weight of the titanium
trichloride component of the catalyst system was 0.04 g.
The results of this example are tabulated in
the Table.
WO 93/23162 2 1 3 5 ll O 1 P~/US93/04385
-17 -
COMPARP.TIYE EXAMPLE 1
Example 1 was identically reproduced but for
the composition of the catalyst system. The catalyst
system of this comparative example omitted the silane
component, isobutylisopropyldimethoxysilane. However,
the molar ratio of titanium trichloride to
triethylaluminum was identical to the molar ratio of
these components in Example 1. That is, the molar ratio
of titanium trichlaride to triethylaluminum was 1:4.6.
Otherwise, the polymerization reaction was conducted in
exact accordance with the polymerization conditions that
existed during the polymerization of
Example 1.
Unfortunately, this example was run for only
20 minutes. The reason for this abbreviated testing
per-iod was that the product produced was so sticky that
stirring could not be maintained even at maximum power.
The polypropylene generated during the 20
mi~ute run was weighed to provide catalyst activity,
albeit over this abbreviated 20 minute period. ~
Unfortunately, the stic~inéss~of the polypropylene
product was such that the only physical property tha-t
could be measured was an analysis of percent heptane
insolubility of the polyprop~lene p~od~ct, which
analysis was determined in accordan~e-with the procedure
set forth in Example 1. That resuIt, in view of low
crystallinity of the polypropylene product, could only
be certain to the extent that the percent heptane
insolubility of the polypropylene product was less than
85%. ~
WO 93/23162 2 1 3 5 ~ O 1 PC~/US93/04385
--1 8--
~= A brlef su~unary of this example is included in
the Table.
,
-
WO93/23162 2 1 3 ~ ~ O 1 PCT/US93/04385
-19-
EXAMPLE 4
In this example propylene was polymerized in
accordance with the procedure set forth in Example 1.
However, the catalyst system utilized in this example
substituted the complex TiCl3Ø33~1Cl3. The other
components were identical with those of Example 1, viz-
isobutylisopropyl-dimethoxysilane ~IBIP) and
triethylaluminum (TEAL3, respectively. ~his catalyst
system also differed from the catalyst system of Example
1 in that it included butyl benzoate (BBE) (0.25 mole).
The molar ratio of titanium compound to silane to
aluminum compound to BBE, moreover, was 1:0.9:7.0:0.25,
respectively. The TiC13.033AlC13 complex, furthermore,
was introduced into the polymerization reactor after
being ballmilled with the BBE component. As in all the
previous examples the first catalyst component, in this
example TiC1,Ø33AlCl3, was present in an amount of 40
mg.
The results of this example are tabulated in
the Table.
WO93/23162 2 1 3 5 ~ O 1 PCT/US93/04385
-20-
EXAMPLE S
The po~ymerization reaction of Example 4 was
reproduced but the silane utilized was
isobutyltrimethoxysilane.
The results of this example are included in
the Table.
~ .
:
_
W093/23162 -21- 2 1 3 5 4 ~ 1 PCT/Vs93/0438s
EXAMPLE 6
A polymerization in accordance with Example 4
was identically reproduced but the silane was
diisopropyldimethoxysilane.
The results of Example 6 are incorporated in
the Table.
~, . i
..
.-
,'-`- .
: --
,. . .
._ I
WO93t23162 2 1 ~ ~ ~ O 1 PCT/US93/04385
-22-
EXAMPLE 7
A polymerization in accordance with Example 4
was reproduced. However, although the catalyst system
of this example included TiCl3.AlCl3, as well as IBIP
and TEAL as components, this catalyst system did not
include butyl benzoate (~BE). This catalyst system also
differed from the catalyst system of Example 4 in that
the molar ratio of titanium compound to silane to
aluminum compound was l.0:0.9:lO.0, respectively.
Moreover, in this example the titanium ~ catalyst
component was introduced into the pol~merization reac~or
in an amount such that its total weight was 75 mg.
Finally, the reaction time was 2 hours inste~d of the l
hour duration employed in Exampl~ 4.
The results of this example are tabulated in
the Table.
. .
_
W093/23~62 -23- 2`1 ~ 5:~ 0 1 PCT/~S93/04385
~- COMPARATIVE EXAMPLE 2
Example 4 was identically reproduced except
for the omission of the silane component. That is, the
catalyst system comprised the complex TiCl3Ø33AlCl3
(40 mg.), ballmilled with BBE, and triethylaluminum
present in a molar ratio of the Ti complex to TEAL to
BBE of 1:7.0:0.25.
An analysis of the polypropylene product of
this reaction is summarized in the Table. It is noted
that no val~es are provided for melt flow rate and bulk
density. These physical properties could not be
obtained because of the extremely low heptane
insolubility of the polypropylene product. That is, the
product obtained was too sticXy to provide accura~e
measurement of these properties in accordance with the 3
standard ASTM tests under which these properties were
measured.
. , ~ ,
W093/23162 2 1 3 5 ~ ~ 1 PCT/US93/0438~
-24-
COMPARATIVE EXAMPLE 3
Example 4 was reproduced except that it was
conducted in accordance with prior art teachings. That
is, although polymerization reac~ion conditions were
identical with Example 4 and the catalyst system again
comprised 40 milligrams of TiC13Ø33AlCl3, the
aluminum-~ontaining compound was not txiethylaluminum
but rather, in accordance with prior art teachings,
diethyla~uminum chloride. As in Comparative Example 2,
the molar ratio of the titanium compound to the
organoaluminum compound, diethylaluminum chloride, was
again l:7.0 with no silane present.
The results of this example are also inc~uded
in the Table.
W ~ 93/23162 ~ 1 3 S i ~ lPCT/US93/0438S
-25-
TABLE
A. The CatalYst System
Molar Ratio of Components
, _ ; - .. .. _ = . = . ,. . _ _
Example TiCl.,. ¦ Total
No. TiCl3 l/3AlCl~ IBIPl IBTMZ DIP3 BBE~ TEA~ ¦ Wt.,
_ _ _ __ _ _ .
1 _ 1 _ _ 0~5 _ 4~6_ 40 i
2 ~ 1 _ 0 ~ 7 _ _ _ 6 ~ 0 . 40
3 1 O~g __ . . 7 5_ 40
~- I 1 - o g _ _. o.~s 4 6 40
l . . , I
1 5 . 1 . . 0-9_ 0.25 7 .0 40 I i
: j 6 1: : 1 I : 0 9 0.25 7.0 40 I .
~ 77 1 0.9 10.0 75
.
`~ ce:~ -~ ~ 1 ; _ 0~2S 7~0 40
CE3 l 1 r-- 0 ~ 25 _ 40
PolYmerization Conditions: Footnotes:
Time: -1 hour 'Isobutylisopropyldimethoxysilane
Tem~.- 70C- 71sobutyltrimethoxysilane
Pressure 460 psig ~Diiso~ropyldimethoxysilane
~ Hydrogen: 400 ml Butylbenzoate
:~ Stirring: 400:rpm -'Triethylaluminum
~:~ Total-Ti-G~nt2~ning Component ~Diethylaluminum chloride
Wt: 40 mg~ 'Tot~l Ti-Containing Component Wt: 75
mg. and 2-hour polymerization
_, - J
-- _
. _ _ . _ .
W O 93/23162 ~ 1 3 ~ 4 0 1 P~r/US93/04385 -26-
B. PolYpropvlene Reaction and Product
. _ _ . -- .- . _ .
Example Activity, MFR,g/10 ¦ Bulk Dens.,
No . g . PP/g . Cat . Ti ,ppm ~ ~lI min .I lb . /f t~ '
_ _ _ _ , . -
1 5,~50 ~2 94 7 2.4 27.0
2 6,15G 51 97.75 0.8 25.5
, __ _ . .- . .
3 6,820 47.5 99.5 0.7 26.7
.. . .,
~El 3,200- _ <85 _ . .~ .
. -
4 5,625 40 96.5 1.018.6 _
2,600 ~9 _ 94.5 2.0 18.0
6 5,625 _ 38 97 S 1.0_ 20
_ , __
7 1,640 149_ ~0.6 3.5 18.0 _
. ~
CE2 2,000 120 85.0
I
. ¦ -- CE3 1,900 124 97.4 _ 7.0 20.2
*Could not be processed.
-
213.5~01
WO93/23162 PCT/US93/04385
-27-
ANALYSIS OF RESULTS
An analysis of. the Table establishes that the
examples within the contemplation of the catalyst system
of the present invention produce acceptable catalyst
activities. Moreover, the isotacticity, as m~asured by
percent heptane insolubility, is superior to that of the
examples utilizing .prior art catalyst systems. Indeed,
Comparative Examples l and 2, because of the low level
of isotacticity in the polypropylene product, could not
be processed~
~ The only exception to the above remarks is the
comparison between Example 7 and Comparative ~.xample 3.
These two examples differed by the presence in the
catalyst system of Example 7 of the silane IBIP which
silane was not present in the catalyst system of
Comparative Example 3. In addition, the aluminum
compound of Example 7, in accordance with the present
invention~, was a trialkylaluminum compound, TEAL, .
whereas~the~a1uminum compound of the catalyst system of
Comparat:ive~Example 3 was diethylaluminum chloride.
The aatalyst system of Comparative Example 3
had marginally:improved catalyst~activity compared to
the catalyst:system~of Example 7. However, ~he degree
of po~ymerization of the:polypropyle~e produced using
the;catalyst-~-syçtem-of~ Comparative Example 3 was
significantly lower than tne polypropylene produced
using the catalyst system of Example 7. This is
manifested by the.melt flow rate which, as those skilled
in the art are aware, is a measure of polymer viscosity,
which is proportional to the degree of polymerization.
_
I
W093/23 2 213~401
16 PCl /US~3/04385
-28-
The lower the melt ~low rate the greater the
polypropylene viscosity.
:
