Note: Descriptions are shown in the official language in which they were submitted.
CA 02338767 2001-O1-25
D-17901
-1-
UNBRIDGED MONOCYCLOPENTADIENYL METAL COMPLEX
CATALYST HAVING IMPROVED TOLERANCE OF MODIFIED
METHYLALUMINOXANE
Field of the Invention
The invention relates to a catalyst composition for olefin
polymerization and a process for polymerizing polyolefins, especially
copolymers of ethylene-alpha olefins, ethylene-alpha olefin-dienes, and
polypropylene using a metallocene catalyst. More particularly, the
invention concerns the polymerization of polyolefins having less than
50% crystallinity using a metallocene catalyst containing a transition
metal and an aluminoxane.
Background of the Invention
There has been a growing interest in the use of metallocenes for
polyolefin production. l~Ianv metallocen~s for polyolefin production are
difficult and time-consuming to prepare, require large amounts of
alumoxane, and exhibit poor reactivity toward higher olefins,
especially for making ethylene-alpha olefin copolymers and ethylene-
alpha olefin-dime terpolymers. Moreover, the ethylene-alpha olefin
copolymers and ethylont~-alpha olefin-dime terpolymers prepared
using these metallocenooften have undesirably low molecular weights
(i.e., Mw less that 50,000).
The so-called "constrained geometry" catalysts such as those
disclosed in EP 0 420 436 and EP 0 416 815 can provide a high
comonomer response and a high molecular weight copolymer, but are
difficult to prepare and purify, and, therefore, are expensive. Another
drawback of the bridged amido-cyclopentadienyl titanium catalyst
system is that in order to form an active oxide-supported catalyst, it is
CA 02338767 2001-O1-25
D-17901
-2-
necessary to use fairly high levels of alumoxane (see, e.g.,
W096/16092) or to employ mixtures of aluminum alkyl and an
activator based on derivatives of tris(pentafluorophenyl)borane (see,
e.g., W095/07942), itself an expensive reagent, thus raising the cost of
running the catalyst. In the constrained geometry catalyst art, such as
in EP 0 416 815 A2 (page 2, lines 5-9 and 43-51), it is pointed out that
the angle formed by the cyclopentadienyl centroid, transition metal,
and amide nitrogen is critical to catalyst performance. Indeed,
comparison of the published result using a bridged amido-
cyclopentadienyl titanium systems with similar unbridged systems has
generally shown the unbridged analogs to be relatively inactive. One
such system, described in U.S. Patent No. 5,625,016, shows very low
activity, while having some of the desirable copolymerization behavior.
In Idemitsu Kosan JPO 8/231622, it is reported that the active
catalyst may be formed starting from (C5Me5)Ti(OMe)3 and that the
polymer formed has a relatively wide or broad compositional
distribution. The present invention does not utilize this precursor.
Typically, polyolefins such as EPRs and EPDMs are produced ,
commercially using vanadium catalysts. In contrast to other
polyolefins produced using vanadium catalysts, those produced by the
catalysts of the present invention have high molecular weight and
narrower composition distribution (i.e., lower crystallinity at an
equivalent alpha olefin content.
There is an on-going need to provide a catalyst employing a
metallocene which is easy to prepare, does not require large amounts
of aluminoxane and which readily copolymerizes to produce ethylene-
alpha olefin copolymers, ethylene-alpha olefin-dime terpolymers, and
polypropylene, as well as producing polyethylene.
D-17901
CA 02338767 2001-O1-25
-3-
SUMMARY OF THE INVENTION
In contrast to the constrained geometry catalysts, the catalyst of
the invention is unconstrained or unbridged and relatively easily and
inexpensively prepared using commercially available starting
materials. Further, the level of aluminoxane utilized can be lowered.
That is, in the present invention, the precursor can be dried onto a
support or dried with a spray drying material with AI:Ti ratios below
100:1 to form highly active catalysts with similar polymerization
behavior to their unsupported analogs of the invention and
polymerization behavior similar to constrained catalysts. Further, the
catalyst of the present invention described herein has improved
reactivity with methylaluminoxane (MMAO) which contains higher
alkyl groups. This enables replacement of some or all of the toluene
employed in the polymerization environment with light aliphatic
hydrocarbons, since MMAO, unlike aluminoxane (MAO), is soluble in
non-aromatic solvents. Use of aliphatic hydrocarbons such as
isopentane is often preferred to toluene,bscause of the greater ease of
purging it from the polymer after it leaves the reactor and also because
of the adverse health concerns associated with aromatic solvents in
general.
Accordingly, the present invention provides a catalyst
comprising:
(A) a transition metal compound having the formula:
(C5R15)TiYg, wherein each R1 substituent is independently selected
from the group consisting of hydrogen, a C1-Cg alkyl, an aryl, and a
heteroatom-substituted aryl or alkyl, with the proviso that no more
than three R1 substituents are hydrogen; and wherein two or more R1
substituents may be linked together forming a ring; and each Y is
_z
CA 02338767 2001-O1-25
D-17901
-4-
independently selected from the group consisting of a C1-C20 alkoxide,
a C 1-C20 amide, a C 1-C20 carboxylate, and a C 1-C20 carbamate;
(B) a compound having the formula: R20H or R3COOH
wherein each R2 or R3 is a C1-Cg alkyl; and
(C) an aluminoxane.
Optionally, the catalyst can additionally contain (D) a bulky
phenol compound having the formula: (CgR45)OH, wherein each R4
group is independently selected from the group consisting of hydrogen,
halide, a C1-Cg alkyl, an aryl, a heteroatom substituted alkyl or aryl,
wherein two or more R4 groups may be linked together forming a ring,
and in which at least one R4 is represented by a Cg-C12 linear or
branched alkyl located at either or both the 2 and 6 position (i.e., the
ortho positions relative to the OH group being in position 1) of the
bulky phenol compound.
There is also provided a polymerization process employing the
catalyst composition and a polymer produced,using the catalyst. A
cable composition is also provided.
Detailed Description of the Invention
Catalyst. The catalva contains a transition metal (titanium)
precursor (Component A), an alcohol or carboxylic acid (Component B),
an aluminoxane (Component C), and optionally a substituted bulky
phenol (Component D),. The catalyst of the invention can be
unsupported (that is, in liquid form), supported, spray dried, or used as
a prepolymer. Support and/or spray drying material is described as
optional Component E.
Component A (A) a transition metal compound having the
formula: (C5R15)TiYg, wherein each R1 substituent is independently
.z
D-17901
CA 02338767 2001-O1-25
-5-
selected from the group consisting of hydrogen, a C1-Cg alkyl, an aryl,
and a heteroatom-substituted aryl or alkyl, with the proviso that no
more than three R1 substituents are hydrogen; and wherein two or
more R1 substituents may be linked together forming a ring; and each
Y is independently selected from the group consisting of a C1-C20
alkoxide, a C 1-C20 amide, a C 1-L2U carboxylate, and a C 1-C20
carbamate. Illustrative compounds can include:
cyclopentadienyltitanium tribenzoate; cyclopentadienyltitanium
tris(diethycarbamate); cyclopentadienyltitanium tris(di-tert-
butylamide); cyclopentadienyltitanium triphenoxide;
pentamethylcyclopentadienyltitanium tribenzoate;
pentamethylcyclopentadienyltitanium tri-pivalate;
pentamethylcyclopentadienyltitanium triacetate;
pentamethylcyclopentadienyltitanium tris(diethycarbamate);
pentamethylcyclopentadienyltitanium tris(di-tent-butylamide);
pentamethylcyclopentadienyltitanium ~riphenoxide; 1,3-
bis(trimethylsilyl)cyclopentadienyltitanium txibenzoate;
tetramethylcyclopentadienyltitanium tribenzoate; fluorenyltitanium
trichloride; 4,5,6,7-tetrahydroindenyltitanium tribenzoate; 4,5,6,7-
tetrahydroindenyltitanium tripivalate; 1,2,3,4,5,6,7,8-octahydro-
fluorenyltitanium tribenzoate; 1,2,3,4,5,6,7,8-octahydro-
fluorenyltitanium tris(diethylcarbamate); 1,2,3,4-tetrahydrofluorenyl-
titanium tribenzoate; 1,2,3,4-tetrahydrofluorenyl-titanium tris(di-tert-
butylamide); 1,2,3-trimethylcyclopentadienyltitanium tributyrate;
1,2,4-trimethylcyclopentadienyltitanium tribenzoate; 1,2,4-
trimethylcyclopentadienyltitanium triacetate; 1-~a-butyl-3-
methylcyclopentadienyltitanium tribenzoate; 1-n-butyl-3-
methylcyclopentadienyltitanium tripivalate; methylindenyltitanium
tripropionate; 2-methylindenyltitanium tribenzoate; 2-
CA 02338767 2001-O1-25
D-17901
-6-
methylindenyltitanium tris(di-n-butylcarbamate); 2-
methylindenyltitanium triphenoxide; and 4,5,6,7-tetrahydro-2-
methylindenyltitanium tribenzoate. In the pre-cursor, a heteroatom is
an atom other than carbon (e.g, oxygen, nitrogen, sulfur and so forth)
in the ring of the heterocyclic moiety.
Component B is an alcohol having the formula: R20H or
R3COOH, wherein each R2 or R3 is a C1-Cg alkyl. Illustrative R20H
compounds in which R2 is alkyl can include, for example, methanol,
ethanol, propanol, butanol (including n- and t- butanol), pentanol,
hexanol, heptanol, octanol. Preferably, R2 is a methyl group.
Illustrative of R3COOH compounds are acetic acid, propionic acid,
benzoic acid, and pivalic acid. Preferred among these are benzoic and
pivalic acid.
Component C is a cocatalyst capable of activating
the catalyst precursor is employed as Component D. Preferably,
the activating cocatalyst is a linear or c~yolic oligomeric
poly(hydrocarbylaluminum oxide) which contain repeating units
of the general formula -(Al(R*)O)-, where R* is~fiydrogen, an alkyl
radical containing from 1 to about 12 carbon atoms, or an aryl
radical such as a substituted or unsubstituted phenyl or naphthyl
group. More preferably, the activating cocatalyst is an
aluminoxane such as methylaluminoxane (MAO) or modified
methylaluminoxane (MMAO).
Aluminoxanes are well known in the art and
comprise oligomeric linear alkyl aluminoxanes represented by the
formula:
CA 02338767 2001-O1-25
D-17901
-7-
R*** Al-O AlR***2
R***
and oligomeric cyclic alky-1 alamix~oxanes of the formula:
-Al-O-
R***
P
wherein s is 1-40, preferably 10-20; p is 3-40, preferably 3-20; and
R*** is an alkyl group containing 1 to 12 carbon atoms,
preferably methyl.
Aluminoxanes may be pre~~axed in a variety of ways.
Generally, a mixture of linear and cyclic aluminoxanes is
obtained in the preparation of aluminoxanes from, for example,
trimethylaluminum and water. For example, an aluminum alkyl
may be treated with water in the form of a moist solvent.
Alternatively, an aluminum alkyl, such as trimethylaluminum,
may be contacted with a hydrated salt, such as hydrated ferrous
sulfate. The latter method comprises treating a dilute solution of
trimethylaluminum in, for example, toluene with a suspension of
ferrous sulfate heptahydrate. It is also possible to form
methylaluminoxanes by the reaction of a tetraalkyl-
dialuminoxane containing C2 or higher alkyl groups with an
amount of trimethylaluminum that is less than a stoichiometric
excess. The synthesis of methylaluminoxanes may also be
CA 02338767 2001-O1-25
D-17901
_g_
achieved by the reaction of a trialkyl aluminum compound or a
tetraalkyldialuminoxane containing C2 or higher alkyl groups
with water to form a polyalkyl aluminoxane, which is then
reacted with trimethylaluminum. Further, modified
methylaluminoxanes, which contain both methyl groups and
higher alkyl groups, i.e., isobutyl groups, may be synthesized by
the reaction of a polyalkyl aluminoxane containing C2 or higher
alkyl groups with trimethylaluminum and then with water as
disclosed in, for example, U.S. Patent No. 5,041,584.
The mole ratio of aluminum atoms contained in the
poly(hydrocarbylaluminum oxide) to total metal atoms contained in the
catalyst precursor is generally in the range of from about 2:1 to about
100,000:1, preferably in the range of from about 10:1 to about 10,000:1,
and most preferably in the range of from about 50:1 to about 2,000:1.
Preferably, Component C is an alumoxane of the formula
(A1R50)m(A1R60)n in which R5 is a methyl group, R6 is a C1-Cg alkyl,
m ranges from 3 to 50; and n ranges from 1 to 20. Most preferably, R6,
is a methyl group.
Component D is optional and is a bulky phenol compound
having the formula: (CgR45)OH, wherein each R4 group is
independently selected from the group consisting of hydrogen, halide, a
C1-Cg alkyl, an aryl, a heteroatom substituted alkyl or aryl, wherein
two or more R4 groups may be linked together forming a ring, and in
which at least one R4 is represented by a Cg-C12 linear or branched
alkyl located at either or both the 2 and 6 position (i.e., the ortho
positions relative to the OH group being in position 1) of the bulky
phenol compound;. In the formula, preferably none of the R4 groups is
a methoxy group. Preferably, suitable R4 groups can include, for
example, t-butyl, isopropyl, n-hexyl and mixtures thereof.
CA 02338767 2001-O1-25
D-17901
-9-
Component E. Preferably, the catalyst of the invention is
unsupported. However, optionally, one or more of the above-described
catalyst components may be impregnated in or deposited on a support,
or alternatively spray dried with a support material. These support or
spray drying materials are typically solid materials which are inert
with respect to the other catalyst components and/or reactants
employed in the polymerization process. Suitable support or spray
drying materials can include silica, carbon black, polyethylene,
polycarbonate, porous crosslinked polystyrene, porous crosslinked
polypropylene, alumina, thoria, titania, zirconia, magnesium halide
(e.g., magnesium dichloride), and mixtures thereof. Preferred among
these support materials are silica, alumina, carbon black, and mixtures
thereof. These are composed of porous particulate supports that
usually have been calcined at a temperature sufficient to remove
substantially all physically bound water.
The molar ratio of Component B to Component A ranges from
about 2:1 to 200:1; preferably about 2:1, tn 50:1; and, most preferably, is
about 2:1 to 20:1. The molar ratio of Compopent D to Component A
ranges from about 5:1 to 1000:1; preferably about 10:1 to 300:1; and,
most preferably is about 30:1 to 200:1. The molar ratio of Component
C to Component A ranges from about 10:1 to 10,000:1, preferably about
30:1 to 2,000:1, and most preferably, is about 50:1 to 1000:1, with the
provisos that (1) the ratio of Component B to Component C does not
exceed 0.7:1, and is preferably between 0.001:1 to 0.050:1; and (2) the
ratio of Component D to Component C does not exceed 1:1, and is
preferably below 0.7:1. When Component E is employed as a support
or spray drying material, it is employed in an amount ranging from
about 7 to 200 g/mmol, preferably 12 to 100 g/mmol, and most
preferably 20 to 70 glmmol (grams of Component E per millimole
Component A).
z
CA 02338767 2001-O1-25
D-17901
- 10-
Process for Makin,~ the Catalyst. The individual catalyst
components (Components A, B, C, and optionally D and E) can be
combined in any order prior to polymerization. Alternatively, the
individual catalyst components can be fed to the polymerization reactor
such that the catalyst is formed in-situ.
Preferably, the active catalyst is prepared as follows. In Step 1,
Components A and B are mixed in an inert hydrocarbon solvent
suitable for dissolving Components A through C, and optionally also D,
under an inert atmosphere (e.g., nitrogen) for at least 15 minutes or
longer (e.g., up to 3 days). The components are combined such that
Component A is mixed with at least three molar equivalents of
Component B. Typical inert solvents can include, for example, toluene,
xylene, chlorobenzene, etc. Preferred among these solvents is toluene.
In Step 2, Component C (or Component C and Component D,
when employed) is mixed in one of the above-described inert
hydrocarbon solvents, preferably the same solvent employed in Step 1,
under an inert atomosphere (e.g., nitrog~u and/or argon) for at least 15
minutes or longer (e.g., for up to 3 days). The ratio of aluminum (in
the aluminoxane, Component C) to phenol of tlie'bulky phenol
compound (Component D) ranges from 1.4:1 to 1000:1; preferably 3:1 to
100:1; most preferably 3:1 to 10:1.
Optionally, the support or spray drying material (Component E)
can be added to any of the above-described solutions, mixtures, and/or
slurries. When Component E is employed the mixing should take place
for about 30 minutes or more and the ratio of aluminum to support
material is in the range of about 0.5 to 10 mmol./g., preferably, 2 to 5
mmol./g.
In Step 3, the mixture of Components A and B is combined with
the mixture of Components C (or Components C and D, when D is
employed) (and optional E) in such proportion that the molar ratio of
:,
CA 02338767 2001-O1-25
D-17901
-11-
aluminum to transition metal is about 5 to 5000, preferably 30 to 1000,
and the molar ratio of Component B to aluminum is less than 0.5. The
mixture is stirred for at least about 5 minutes. The mixture can be
used as a liquid for direct injection into the polymerization reactor, or,
if Component E is present, may be dried in vacuo to a free-flowing
powder or spray-dried in an inert atmosphere. If Component E is not
present, the catalyst is then fed to the reactor in liquid form. If
Component E is present and the catalyst is in solid form, it may be
introduced into the reactor by a variety of methods known to those
skilled in the art such as by inert gas conveyance or by injection of a
mineral oil slurry of the catalyst.
While not wishing to be bound by any theory, it is believed that
the function of the two protic reagents (Components B and C) is to
prevent the degradation of the cationic titanium (I~ active site. It is
known that the aluminum trialkyl (A1R3) compounds will rapidly
reduce the oxidation state of titanium from +4 to +3. However, it is
usually advantageous to have A1R3 or ~ruminoxanes present during
polymerization to serve as scavengers of catalyst poisons which adhere'
to reactor surfaces or are introduced by reaction media such as
monomers, inert gases, and (if appropriate) solvents. Therefore, the
catalyst of the invention represents a solution to the titanium
reduction problem which allows the presence of alkylaluminum
species. It has been poaulated that the first step in the activation of
titanium by cocatalyst is alky lation, that is, the exchange of two or
more titanium substituents with alkyl groups on aluminum atom(s).
Then the reason the catalysts based on titanium carboxylates are more
active than their trihalide analogs under certain polymerization
conditions (notable for EPDM polymerization) is that the aluminum
carboxylates which are immediately formed from the alkylation
reaction of the tricarboxylates serve as bulky groups. It is believed
CA 02338767 2001-O1-25
D-17901
-12-
that these bulky groups prevent a close interaction of the aluminum
species with the alkylated titanium species, thus hindering the
reduction and complexation reactions.
Polymerization Process and Conditions. The above-described
catalyst composition can be used for the polymerization of monomers
(e.g., olefins, diolefins, and/or vinyl aromatic compounds) in a
suspension, solution, slurry, or gas phase process using known equip-
ment and reaction conditions, and it is not limited to any specific type
of reaction. However, the preferred polymerization process is a gas
phase process employing a fluidized bed. The gas ffuidized bed reactor
can be assisted by mechanical stirring or agitation means. Gas phase
processes employable in the present invention can include so-called
"conventional" gas phase processes, "condensed-mode," and, most
recent, "liquid-mode" processes.
In many processes, it is desirable to include a scavenger in the
reactor to remove adventitious poisons slzph as water or oxygen before
they can lower catalyst activity. In such cases, it is recommended that
trialkylaluminum species (e.g., TIBA) not be used, but rather that
methylalumoxane be employed for such purposes.
Conventional fluidized processes are disclosed, for example, in
U.S. Patent Nos. 3,922,322; 4,035,560; 4,994,534, and 5,317,036.
Condensed mode polymerizations, including induced condensed
mode, are taught, for example, in U.S. Patent Nos. 4,543,399;
4,588,790; 4,994,534; 5,317,036; 5,352,749; and 5;462,999. For
polymerizations producing alpha olefin homopolymers and copolymers
condensing mode operation is preferred.
Liquid mode or liquid monomer polymerization mode is
described in U.S. Patent No. 4,453,471; U.S. Serial No. 510,375; and
W O 96/04322 (PCT/US95/09826) and WO 96/04323 (PCT/US95/09827).
CA 02338767 2001-O1-25
D-17901
-13-
In liquid mode or liquid monomer polymerizations the temperature in
the polymerization zone of the reaction vessel is maintained below the
dew point of at least one of the monomers employed. Fluidization is
achieved by a high rate of fluid recycle to and through the bed,
typically in the order of about 50 times the rate of feed of make-up
fluid. The fluidized bed has the general appearance of a dense mass of
individually moving particles as created by the percolation of gas
through the bed.
For polymerizations such as ethylene-propylene copolymer (e.g.,
EPMs), ethylene-propylene-dime terpolymer (e.g., EPDMs), and
diolefin (e.g., butadiene, isoprene) polymerizations, it is preferable to
use liquid mode and to employ an inert particulate material, a so-
called ffuidization aid. Inert particulate materials are described, for
example, in U.S. Patent No. 4,994,534 and include carbon black, silica,
clay, talc, and mixtures thereof. Of these, carbon black, silica, and
mixtures of them are preferred. When employed as fluidization aids,
these inert particulate materials are use~din amounts ranging from
about 0.3 to about 80% by weight, preferably,about 5 to 50% based on ,
the weight of the polymer produced. The use of inert particulate
materials as fluidization aids in polymer polymerization produces a
polymer having a core-shell configuration such as that disclosed in U.S.
Patent No. 5, 304, 588. The catalyst of the invention in combination
with one or more of these fluidization aids produces a resin particle
comprising an outer shell having a mixture of a polymer and an inert
particulate material, wherein the inert particulate material is present
in the outer shell in an amount higher than 75% by weight based on
the weight of the outer shell; and an inner core having a mixture of
inert particulate material and polymer, wherein the polymer is present
in the inner core in an amount higher than 90% by weight based on the
weight of the inner core. In the case of sticky polymers, these resin
CA 02338767 2001-O1-25
D-17901
-14-
particles are produced by a ffuidized bed polymerization process at or
above the softening point of the sticky polymer.
The polymerizations can be carried out in a single reactor or
multiple reactors, typically two or more connected in series, can also be
employed. The essential parts of the reactor are the vessel, the bed,
the gas distribution plate, inlet and outlet piping, at least one
compressor, at least one cycle gas cooler, and a product discharge
system. In the vessel, above the bed, there is a velocity reduction zone,
and in the bed a reaction zone.
Generally, all of the above modes of polymerizing are carried out
in a gas phase ffuidized bed containing a "seed bed" of polymer which
is the same or different from the polymer being produced. Preferably,
the bed is made up of the same granular resin that is to be produced in
the reactor.
The bed is fluidized using a ffuidizing gas comprising the
monomer or monomers being polymerized, initial feed, make-up feed,
cycle (recycle) gas, inert carrier gas (e.g ; nitrogen, argon, or inert
hydrocarbon such as methane, ethane, propane, isopentane) and, if
desired, modifiers (e.g., hydrogen). Thus, during the course of a
polymerization, the bed comprises formed polymer particles, growing
polymer particles, catalyst particles, and optional flow aids
(fluidization aids) fluidizod by polymerizing and modifying gaseous
components introduced at a flow rate or velocity sufficient to cause the
particles to separate and act as a fluid.
In general, the polymerization conditions in the gas phase
reactor are such that the temperature can range from sub-atomos-
pheric to super-atmospheric, but is typically from about 0 to 120°C,
preferably about 40 to 100°C, and most preferably about 40 to
80°C.
Partial pressure will vary depending upon the particular monomer or
CA 02338767 2001-O1-25
D-17901
-15-
monomers employed and the temperature of the polymerization, and it
can range from about 1 to 300 psi (6.89 to 2,0067 kiloPascals),
preferably 1 to 100 psi (6.89 to 689 kiloPascals). Condensation
temperatures of the monomers such as butadiene, isoprene, styrene are
well known. In general, it is preferred to operate at a partial pressure
slightly above to slightly below (that is, for example, + 10°C for low
boiling monomers) the dew point of the monomer.
Polymers Produced. Olefin polymers that may be produced
according to the invention include, but are not limited to,
ethylene homopolymers, homopolymers of linear or branched
higher alpha-olefins containing 3 to about 20 carbon atoms, and
interpolymers of ethylene and such higher alpha-olefins, with
densities ranging from about 0.84 to about 0.96. Homopolymers
and copolymers of propylene can also be produced by the
inventive catalyst and process. Suitable higher alpha-olefins
include, for example, propylene, 1-butene, 1-pentene, 1-hexene, 4-
methyl-1-pentene, 1-octene, and 3,5,5-tximethyl-1-hexene.
Preferably, the olefin polymers according to tie invention can
also be based on or contain conjugated or non-conjugated dimes,
such as linear, branched, or cyclic hydrocarbon dimes having
from about 4 to about 20, preferably 4 to 12, carbon atoms.
Preferred dimes include 1,4-pentadiene, 1,5-hexadiene, 5-vinyl-2-
norbornene, 1,7-octadiene, 7-methyl-1,6-octadiene, vinyl
cyclohexene, dicyclopentadiene, butadiene, isobutylene, isoprene,
ethylidene norbornene and the like. Aromatic compounds having
vinyl unsaturation such as styrene and substituted styrenes, and
polar vinyl monomers such as acrylonitrile, malefic acid esters,
vinyl acetate, acrylate esters, methacrylate esters, vinyl trialkyl
silanes and the like may be polymerized according to the
invention as well. Specific olefin polymers that may be made
CA 02338767 2001-O1-25
D-17901
-16-
according to the invention include, for example, polyethylene,
polypropylene, ethylene/propylene rubbers (EPR's), ethylene/pro-
pylene/diene terpolymers (EPDM's), polybutadiene, polyisoprene,
and the like.
The present invention provides a cost-effective catalyst and
method for making compositionally homogeneous, high-molecular
weight ethylene-alpha olefin copolymers with very high levels of
alpha olefin. One advantage is that the catalyst has a very high
comonomer response, so the ratio of alpha olefin to ethylene
present in the reaction medium can be very low, which increases
the partial pressure of ethylene possible in the reactor. This
improves catalyst activity. It also lessens the level of residual
comonomer which must be purged or otherwise recovered from
the polymer after it exits the reactor. The catalyst is also suit-
able for incorporation of non-conjugated dienes to form completely
amorphous rubbery or elastomeric compositions. The catalyst's
very high comonomer response also makes it a good candidate for
the incorporation of long-chain branching into the polymer
architecture through the insertion of vinyl-ended polymer chains
formed via (3-hydride elimination. The ethylene copolymers
produced by the present invention have polydespersity values
(PDI) ranging from 2 to 4.6, preferably 2.6 to 4.2.
Polymers produced using the catalyst and/or process of the
invention have utility in wire and cable applications, as well as in
other articles such as molded and extruded articles such as hose,
belting, roofing materials, tire components (tread, sidewall,
inner-liner, carcass, belt). Polyolefins produced using the catalyst
and/or process of the invention can be cross-linked, vulcanized or
cured using techniques known to those skilled in the art.
D-17901
CA 02338767 2001-O1-25
-17-
In particular, there is provided by the invention a cable
comprising one or more electrical conductors, each, or a core of
electrical conductors, surrounded by an insulating composition
comprising a polymer produced in a gas phase polymerization
process using the catalyst of the invention. Preferably, the
polymer is polyethylene; a copolymer of ethylene, one or more
alpha-olfins having 3 to 12 carbon atoms, and, optionally, a
diene(s).
Conventional additives, which can be introduced into the cable
and/or polymer formulation, are exemplified by antioxidants, coupling
agents, ultraviolet absorbers or stabilizers, antistatic agents, pigments,
dyes, nucleating agents, reinforcing fillers or polymer additives, slip
agents, plasticizers, processing aids, lubricants, viscosity control
agents, tackifiers, anti-blocking agents, surfactants, extenders oils,
metal deactivators, voltage stabilizers, flame retardant fillers and
additives, crosslinking agents, boosters, and catalysts, and smoke
suppressants. Fillers and additives can ~e added in amounts ranging
from less than about 0.1 to more than about 200 parts by weight for
each 100 parts by weight of the base resin, for ekample, polyethylene.
Examples of antioxidants are: hindered phenols such as
tetrakis[methylene(3,5-di-tert- butyl-4-hydroxyhydrocinnamate)]-
methane, bis[(beta-(3,5 di-tert-butyl-4-hydroxybenzyl)-methylcarb-
oxyethyl)]sulphide, 4,4'-thiobis(2-methyl-6-tert-butylphenol), 4,4'-thio-
bis(2-tert-butyl-5-methylphenol), 2,2'-thiobis(4-methyl-6-tert-butyl-
phenol), and thiodiethylene bis(3,5 ditert-butyl-4-hydroxy)hydro-
cinnamate; phosphites and phosphonites such as tris(2,4-di-tert-butyl-
phenyl) phosphite and di-tert-butylphenyl-phosphonite; thio com-
pounds such as dilaurylthiodipropionate, dimyristylthiodipropionate,
and distearylthiodipropionate; various siloxanes; and various amines
such as polymerized 2,2,4-trimethyl-1,2-dihyroquinoline. Antioxidants
CA 02338767 2001-O1-25
D-17901
-18-
can be used in amounts of about 0.1 to about 5 parts by weight per 100
parts by weight of polyethylene.
The resin can be crosslinked by adding a crosslinking agent to
the composition or by making the resin hydrolyzable, which is accom-
plished by adding hydrolyzable groups such as -Si(OR)3 wherein R is a
hydrocarbyl radical to the resin structure through copolymerization or
grafting.
Suitable crosslinking agents are organic peroxides such as di-
cumyl peroxide; 2,5-dimethyl- 2,5-di(t-butylperoxy) hexane; t-butyl
cumyl peroxide; and 2, 5-dimethyl-2, 5-di(t-butylperoxy)hexane-3.
Dicumyl peroxide is preferred.
Hydrolyzable groups can be added, for example, by copoly-
merizing ethylene with an ethylenically unsaturated compound having
one or more -Si(OR)3 groups such as vinyltrimethoxy- silane, vinyltri-
ethoxysilane, and gamma-methacryloxypropyltrimethoxysilane or
grafting these silane compounds to the resin in the presence of the
aforementioned organic peroxides. The ~ydrolyzable resins are then
crosslinked by moisture in the presence of a silanol condensation
catalyst such as dibutyltin dilaurate, dioctyltiri'inaleate, dibutyltin
diacetate, stannous acetate, lead naphthenate, and zinc caprylate.
Dibutyltin dilaurate is preferred.
Examples of hydrolyzable copolymers and hydrolyzable grafted
copolymers are ethylene/ viny ltrimethoxy silane copolymer, ethy-
lene/gamma- methacryloxypropyltrimethoxy silane copolymer,
vinyltrimethoxy silane grafted ethylene/ethyl acrylate copolymer,
vinyltrimethoxy silane grafted linear low density ethylene/1-butene
copolymer, and vinyltrimethoxy silane grafted low density poly-
ethylene.
The cable and/or polymer formulation can contain a poly-
ethylene glycol (PEG) as taught in EP 0 735 545.
CA 02338767 2001-O1-25
D-17901
-19-
The cable of the invention can be prepared in various types of
extruders, e.g., single or twin screw types. Compounding can be
effected in the extruder or prior to extrusion in a conventional mixer
such as Brabender~ mixer or Banbury mixer. A description of a
conventional extruder can be found in U.S. Patent No. 4,857,600. A
typical extruder has a hopper at its upstream end and a die at its
downstream end. The hopper feeds into a barrel, which contains a
screw. At the downstream end, between the end of the screw and the
die, is a screen pack and a breaker plate. The screw portion of the
extruder is considered to be divided up into three sections, the feed
section, the compression section, and the metering section, and two
zones, the back heat zone and the front heat zone, the sections and
zones running from upstream to downstream. In the alternative, there
can be multiple heating zones (more than two) along the axis running
from upstream to downstream. If it has more than one barrel, the
barrels are connected in series. The length to diameter ratio of each
barrel is in the range of about 15:1 to abb~zt 30:1. In wire coating,
where the material is crosslinked after extrusion, the die of the
crosshead feeds directly into a heating zone, anc~ this zone can be
maintained at a temperature in the range of about 130°C to about
260°C, and preferably in the range of about 170°C to about
220°C.
All references cited herein are incorporated by reference.
Whereas the scope of the invention is set forth in the appended
claims, the following specific examples illustrate certain aspects of the
present invention. The examples are set forth for illustration only and
are not to be construed as limitations on the invention, except as set
forth in the claims. All parts and percentages are by weight unless
otherwise specified.
CA 02338767 2001-O1-25
D-17901
-20-
Ezamples
Glossary and abbreviations:
DSC: differential scanning calorimetry
DTBP: 2,6-di-t-butylphenol
ENB: 5-ethylidene-2-norbornene
FI: I3o~~ ind.e~:, ASTM standard I21, in dg/min
ICP: inductively coupled plasma method for elemental
analysis
Irganox Irganox~ 1076, a product of Ciba-Geigy
Kemamine Kemamine~ AS-990, a product of Witco Corp.
MAO: methylalumoxane (Ethyl/Albemarle, solution in
toluene, 1.8 or 3.6 moles Al/L)
MMAO modified methylalumoxane (Akzo Nobel)
PDI: polydispersity index, or Mw/Mn
PRT: peak recrystallization temperature, or the
exothermic peak of the cooling trace in a DSC
experiment ,
SEC: size-exclusion chromatography method for
molecular weight estimation
TIBA triisobutylaluminum, 0.87 mol/L in hexanes
Materials
Pentamethylcyclopentadienyltitanium trichloride and
indenyltitanium trichloride were obtained from Strem Chemicals Inc.,
and used without further purification.
Examples 1 - 5.
D-17901
CA 02338767 2001-O1-25
-21-
These examples demonstrate the use of the catalyst of this
invention to copolymerize ethylene and 1-hexene. In these examples,
the toluene was dried first by holding over anhydrous MgS04 for at
least 7 days, followed by filtration through paper, sparging with
nitrogen, storage over sodium/potassium alloy for at least 24 hours,
and filtration through dried alumina. Thus dried, it was stored in a
drybox under nitrogen.
Example 1.
Preparation of (C5Me5)Ti(02CPh)3.
All manipulations were conducted under nitrogen atmosphere.
A Schlenk flask was charged with stirbar, 25 mL dry toluene, and 2.01
g (C5Me5)TiCl3 (6.94 mmol). In a second flask were placed 3.37 g
benzoic acid (27.6 mmol) and stirbar, and the solution of (C5Me5)TiCl3
was transferred thereto via cannula. To the resulting orange mixture
were added 2.9 mL (20.7 mmol) triethylamine, and the solution was
allowed to stir at ambient temperature for 3 hours and then was
filtered. The solid was washed with toluene,'leaving it colorless. The
filtrate was reduced in uacuo to approx. 10 mL;'and then was held at -
21°C for cap. 5 hours. The mixture was then filtered and washed with
cold toluene, and briefly dried by nitrogen flowing through the filter
cake, leaving 0.74 r g oran~o-yellow solid. The 1H nmr spectrum
revealed the presence of residual solvent and benzoic acid. The latter
was estimated to be 0.83 molar equivalents per titanium atom. After
subtracting out the contributions from benzoic acid, the major nmr
peaks for the titanium complex are as follows (8, solvent CD2C12): (1H
nmr) 7.97 (2H, d, J = 7.1 Hz), 7.52 (1H, m), 7.40 (2H, t, J = 7.5 Hz),
2.12 (15H, s); (13C {1H} nmr) 133.1, 129.2, 128.6, 11.8.
CA 02338767 2001-O1-25
D-17901
-22-
A toluene solution of (C5Me5)Ti(02CPh)3 containing 0.83 eq.
benzoic acid (0.025 g in 5 mL, 7.7 mmol Ti/L) was prepared under
nitrogen. A mixture was prepared composed of 1 mL above solution
and 0.32 mL of a solution of methanol in toluene (0.123 mol/L, 0.039
mmol MeOH, MeOH/Ti = 5.1) which was stirred for 40 min at room
temperature. A 1.3 L stainless-steel reactor (Fluitron~), dried by
flowing nitrogen while it was held at 100°C for at least 1 hour (h.),
was
cooled, then charged with 650 mL hexane, 40 mL 1-hexene, 0.69 mL
MAO (1.8 mol/L in toluene, 1.24 mmol Al), and 1.4 mL of a solution of
DTBP in toluene (0.182 mol/L, 0.25 mmol, Al/DTBP = 5.0). The reactor
had a removable two-baffle insert and a variable speed propeller-
shaped impeller, which was run at 800 rpm. The reactor was heated to
40°C and vented to release most of the nitrogen, then resealed. The
reactor was heated to 70°C and pressurized with ethylene (100-120
psig, cac. 0.7-0.8 MPa). A sample of the (C5Me5)Ti(02CPh)3/MeOH
mixture (0.33 mL, 1.92 X 10-6 mol Ti) was injected into the reactor and
the temperature allowed to rise to 85°C.' The temperature was held
between 80 and 85°C for the remainder of the test, during which time
ethylene flowed to make up monomer lost to polymerization. At a time
30 min after the injection of the titanium complex, the reaction was
quenched with methanol and the reactor vented. The polymer in
hexane was recovered as a sticky mass which was broken up and dried
in vdcuo overnight at 40°C, yielding 45.6 g rubbery polymer, for a
catalyst activity of 48 kg(PE)/mmol(Ti) ~ h ~ 100psiC2=. The polymer
had MI = 0.09 and FI = 2.2. DSC of the copolymer showed melting
points at 35.2, 65.9, and 115.9°C, with the last peak being about 3% as
tall as the dominant peak (65.9°C) and a total crystallinity of 17.3%;
the peak recrystallization temperature was found to be 52.9°C. SEC
revealed Mw = 2.25 X 105 and Mw/Mn = 2.88. By nmr, the copolymer
contained 25.0 wt % 1-hexene.
CA 02338767 2001-O1-25
D-17901
-23-
Example 2.
A second crop of (C5Me5)Ti(02CPh)3/benzoic acid was obtained
by reducing in vaccuo the mother liquor from which the precursor used
in Example 1 was filtered, cooling and filtering as in Example 1, which
yielded a bright yellow powder. The second crop, however, still
contained benzoic acid (1.4 eq. per Ti).
A toluene solution of (C5Me5)Ti(02CPh)3 containing 1.4 eq.
benzoic acid (0.025 g in 5 mL, 7.0 mmol Ti/L) was prepared under
nitrogen. A mixture was prepared composed of 1 mL above solution
and 0.32 mL of a solution of methanol in toluene (0.123 mol/L, 0.039
mmol MeOH, MeOH/Ti = 5.6) which was stirred for 90 min at room
temperature. The autoclave reactor, dried by flowing nitrogen while it
was held at 100°C for at least 1 h, was cooled, then charged with 650
mL hexane, 40 mL 1-hexene, 0.69 mL MAO (1.8 mol/L in toluene, 1.24
mmol Al), and 1.4 mL of a solution of DTBP in toluene (0.182 mol/L,
0.25 mmol, Al/DTBP = 5.0). The reactor'~as heated to 40°C and
vented to release most of the nitrogen, then resealed. The reactor was
heated to 70°C and pressurized with ethylene ~~100-120 psig, ca. 0.7-
0.8 MPa). A sample of the (C5Me5)Ti(02CPh)3/MeOH mixture (0.33
mL, 1.75 X 10-6 mol Ti) was injected into the reactor and temperature
allowed to rise to 85°C. The temperature was held between 80 and
85°C for the remainder of the test, during which time ethylene flowed
to make up monomer lost to polymerization. At a time 30 min after
the injection of the titanium complex, the reaction was quenched with
methanol and the reactor vented. The polymer in hexane was
recovered as a sticky mass which was broken up and dried in vacuo
overnight at 40°C, yielding 46.3 g rubbery polymer, for a catalyst
activity of 53 kg(PE)/mmol(Ti) ~ h ~ 100psiC2=. The polymer had MI =
0.10 and FI = 2.7. DSC of the copolymer showed melting points at
D-17901
CA 02338767 2001-O1-25
-24-
35.8, 70.1, and 115.9°C, with the last peak being less than 10% as tall
as the dominant peak (70.1°C) and a total crystallinity of 15.1%; the
peak recrystallization temperature was found to be 41.6°C. SEC
revealed Mw = 2.12 x 105 and Mw/Mn = 2.75. By nmr, the copolymer
contained 25.7 wt % 1-hexene.
Example 3.
A toluene solution of (C5Me5)Ti(02CPh)3 containing 1.4 eq.
benzoic acid (0.025 g in 5 mL, 7.0 mmol TiIL) was prepared under
nitrogen. A mixture was prepared composed of 1 mL above solution
and 0.32 mL of a solution of methanol in toluene (0.123 mol/L, 0.039
mmol MeOH, MeOH/Ti = 5.6) which was stirred for 60 min at room
temperature. The autoclave reactor, dried by flowing nitrogen while it
was held at 100°C for at least 1 h, was cooled, then charged with 650
mL hexane, 40 mL 1-hexene, 0.72 mL MMAO (1.74 mol/L in heptane,
1.25 mmol Al), and 1.4 mL of a solution of DTBP in toluene (0.182
mol/L, 0.25 mmol, Al/DTBP = 5.0). The reactor was heated to 40°C and
vented to release most of the nitrogen, then resealed. The reactor was'
heated to 70°C and pressurized with ethylene ~I00-120 psig, ca. 0.7-0.8
MPa). A sample of the (C:,IIe~)Ti(02CPh)3/MeOH mixture (0.33 mL,
1.75 X 10-6 mol Ti) wa: injected into the reactor and the temperature
allowed to rise to 80"C, where it was held for the remainder of the test,
during which time ethylene flowed to make up monomer lost to
polymerization. At a time 30 min after the injection of the titanium
complex, the reaction was quenched with methanol and the reactor
vented. The polymer in hexane was recovered as a viscous solution
and dried in vacuo overnight at 40°C, yielding 19.2 g rubbery polymer,
for a catalyst activity of 22 kg(PE)/mmol(Ti) ~ h ~ 100psiC2=. The
polymer had MI = 0.05 and FI = 1.24. DSC of the copolymer showed
melting points at 34.6, 67.5, and 116.7°C, with the last peak being
CA 02338767 2001-O1-25
D-17901
-25-
about 3% as tall as the dominant peak (67.5°C) and a total
crystallinity
of 14.8%; the peak recrystallization temperature was found to be
45.5°C. SEC revealed Mw = 2.63 x 105 and Mw/Mn = 2.94. By nmr,
the copolymer contained 25.4 wt % 1-hexene.
Example 4.
Preparation of (C5Me5)Ti(02CCMe3)3.
All manipulations were conducted under nitrogen atmosphere.
A Schlenk flask was charged with stirbar, 25 mL dry toluene, and 2.0 g
(C5Me5)TiCl3 (6.9 mmol). In a second flask were placed 2.11 g pivalic
acid (20.7 mmol) and stirbar, and the solution of (C5Me5)TiCl3 was
transferred thereto via cannula. To the resulting orange mixture were
added 2.9 mL (20.7 mmol) triethylamine, and the solution was allowed
to stir at ambient temperature for 3 hours and then was filtered. The
solid was washed with toluene, leaving it colorless. The filtrate was
reduced to an orange oil in vacuo which then crystallized, from which
2.86 g was obtained (85%). The nmr peeks for the titanium complex
are as follows (8, solvent CD2Cl2): (1H nmr),1.94 (15H, s), 1.09 (27H,
s); (13C {1H} nmr) 194.4, 130.3, 38.7, 26.5, 11.2:
A toluene solution of (C5Me5)Ti(02CCMe3)3 (0.025 g in 5 mL,
10.3 mmol Ti/L) was prepared under nitrogen. A mixture was
prepared composed of 1 mL above solution and 0.32 mL of a solution of
methanol in toluene (0.123 mol/L, 0.039 mmol MeOH, MeOH/Ti = 3.8)
which was stirred for 35 min at room temperature. The stainless-steel
reactor, dried by flowing nitrogen while it was held at 100°C for at
least 1 hour (h.), was cooled, then charged with 650 mL hexane, 40 mL
1-hexene, 0.69 mL MAO (1.8 mol/L in toluene, 1.24 mmol Al), and 1.4
mL of a solution of DTBP in toluene (0.182 mol/L, 0.25 mmol, Al/DTBP
= 5.0). The reactor had a removable two-baffle insert and a variable
speed propeller-shaped impeller, which was run at 800 rpm. The
D-17901
CA 02338767 2001-O1-25
-26-
reactor was heated to 40°C and vented to release most of the nitrogen,
then resealed. The reactor was heated to 75°C and pressurized with
ethylene (100 psig, 0.7 MPa). A sample of the
(C5Me5)Ti(02CCMe3)3/MeOH mixture (0.33 mL, 2.5 x 10-6 mol Ti)
was injected into the reactor and the temperature allowed to rise to
80°C, where it stayed for the remainder of the test, during which time
ethylene flowed to make up monomer lost to polymerization. At a time
30 min after the injection of the titanium complex, the reaction was
quenched with methanol and the reactor vented. The polymer in
hexane was recovered as a sticky mass which was broken up and dried
in vacuo overnight at 40°C, yielding 52.8 g rubbery polymer, for a
catalyst activity of 42 kg(PE)/mmol(Ti) ~ h ~ 100psiC2=. The polymer
had MI = 0.17 and FI = 4.4.
Example 5.
The polymerization described in Example 2 was repeated, ekcept
that in place of the DTBP, a 50 molar eguivalents of benzoic acid (0.63
mL of a 0.2 mol/L solution in toluene) were"inixed with the MAO prior
to polymerization. After workup, 1.9 g polymer were obtained. DSC of
the copolymer showed melting points at 34.6 and 65.9°C, and a total
crystallinity of 15.1%; the peak recrystallization temperature was
found to be 44.2°C. SEC revealed Mw = 3.27 X 105 and Mw/Mn = 3.57.
By nmr, the copolymer contained 24.1 wt % 1-hexene.
Examples 6 - 11.
These examples demonstrate the use of the catalyst of this
invention to copolymerize ethylene, propylene, and ENB. In all these
examples, the toluene was used as obtained (Aldrich Chemical Co.,
anhydrous, packaged under nitrogen).
CA 02338767 2001-O1-25
D-17901
-27-
Example 6.
In a glovebox under nitrogen, a small oven dried glass vial was
charged with magnetic stirbar and 0.025 g (C5Me5)Ti(02CPh)3
containing 0.83 eq. benzoic acid. This vial was sealed and brought out
of the glovebox. Toluene (5 mL) was added to the vial to form a
solution with a concentration of 7.7 mmol/L. In another oven dried
glass vial sealed under nitrogen, 0.05 mL methanol (MeOH) was mixed
with lOml toluene resulting in a 0.123 mol/L concentration
MeOH/toluene solution. In a third small oven dried glass vial, 2.06 g of
DTBP and 20mL toluene were added under nitrogen to form a
DTBP/toluene solution with concentration of 0.5 mol/L. A small oven
dried glass vial with a stir bar was sealed under nitrogen. To this vial,
0.5 mL of (C5Me5)Ti(02CPh)3/toluene solution (0.00385 mmol Ti) and
0.16 mL of MeOH/toluene solution were mixed at room temperature for
60 minutes (MeOH/Ti = 5.1). A 100 mL glass oven dried bottle with a
stir bar was sealed with a septum and purged with nitrogen. To this
bottle the following components were added under nitrogen: 50 mL of
hexane; 1.43 mL MMAO (1.74 mol(Al)/L in heptane); 1.0 mL of
DTBP/toluene solution; 0.66 mL of (C5Me5)Ti(~2CPh)3IMeOH
mixture made above and 2 mL of ENB. In this bottle the final active
catalyst was formed with ratios of DTBP/Ti = 130, MeOH/Ti = 5.1,
MMAO/Ti = 650. The 1 L stainless-steel Fluitron reactor was baked
for one hour at 100°C with nitrogen constantly flowing through it. It
was then cooled to 40°C and charged with 500 mL hexane. The
activated catalyst mixture made above was transferred to the reactor
by nitrogen overpressure. The reactor was sealed and the temperature
was brought to 60°C. Ethylene (C2=) and propylene (C3=) gases
(C3=/C2= fill ratio = 1:1) were charged to the reactor until the reactor
pressure reached 90 psi (0.62 MPa). The ratio of the gases was then
adjusted to Cg=/C2= = 0.33. The polymerization was carried out for 1
CA 02338767 2001-O1-25
D-17901
-28-
hour after the introduction of the monomer gases. Two charges of ENB
(0.5 mL) were injected to the reactor under pressure at polymerization
times of 10 min and 30 min. Therefore 3 mL total ENB was charged
to the reactor. Polymerization was terminated by injecting 2 mL of
ethanol killing solution (0.5 g BHT, 1.0 g Kemamine, 0.5 g Irganox in
125 mL of ethanol). The monomer gas flows were shut off and the
reactor was vented and cooled to room temperature. The polymer was
scooped out, blended in methanol and dried in a vacuum oven at 40°C
overnight. The collected polymer weighed 12.0 g, for catalyst activity
of 3.1 kg(EPDM)/mmol Ti/hr. The polymer had FI = 0.52 and a P.R.T of
10.8°C. This demonstrates that MMAO can be used as cocatalyst with
(C5Me5)Ti(02CPh)g in EPDM polymerization
Example 7.
A similar experiment as Example 6 was carried out except that
2.86 mL of MMAO (1.74 mol/L) solution (MMAO/Ti = 1290) was used.
After polymerization only 1.1 g of EPDM polymer was collected which
shows much lower catalyst activity. This demonstrates that MMAO/
(C5Me5)Ti(02CPh)3 ratio is important to EPD~VI polymerization
activity.
CA 02338767 2001-O1-25
D-17901
-29-
Example 8.
A similar experiment as Example 6 was carried out except that
0.86 ml of MMAO (1.74 mollL) solution (MMAO/Ti = 390) was used.
After polymerization, 18.2 g of EPDM polymer was collected for better
catalyst activity of 4.7 kg(EPDM)/mmolTi/h. The nmr analysis of the
EPDM sample shows that it contains 31.8 wt% propylene and 3.4 wt%
ENB, and a PRT of 1.1°C. This further demonstrates that
MMAO/(C5Me5)Ti(02CPh)3 ratio is important to EPDM
polymerization activity.
Example 9.
In a glovebox under nitrogen, a small oven dried glass vial was
charged with magnetic stirbar and 0.025 g (C5Me5)Ti(02CPh)3
containing 0.83 eq. benzoic acid. This vial was sealed and brought out
of the glovebox. Toluene (5 mL) was added to the vial to form a
solution with a concentration of 7.7 mmol/L. In another oven dried
glass vial sealed under nitrogen, 0.05 m~ methanol was mixed with 10
mL toluene resulting in a 0.123 mol/L concentration MeOH/toluene
solution. In a third small oven dried glass vial,.2.06 g of 2,6-di-t-
butylphenol (DTBP) and 20 mL toluene were added under nitrogen to
form a DTBP/toluene solution with concentration of 0.5 mol/L.
A small oven dried glass vial with a stir bar was sealed under
nitrogen. To this vial, 0.5 mL of (C5Me5)Ti(02CPh)3/toluene solution
(0.00385 mmol Ti) and 0.16 mL of MeOH/toluene solution were mixed
at room temperature for 60 minutes (MeOH/Ti = 5.1).
A 100 mL glass oven dried bottle with a stir bar was sealed
with a septum and purged with nitrogen. To this bottle the following
components were added under nitrogen: 50m1 of hexane; 0.30 mL MAO
(3.36 mol/L in toluene); 1.0 mL of DTBP/toluene solution; 0.66 mL of
(C5Me5)Ti(02CPh)3/MeOH mixture made above and 2 mL of ENB. In
CA 02338767 2001-O1-25
D-17901
-30-
this bottle the final active catalyst was formed with ratios of DTBP/Ti
= 130, MeOH/Ti = 5.1, MAO/Ti = 260.
The 1L stainless-steel Fluitron reactor was baked for one hour
at 100°C with nitrogen constantly flowing through it. It was then
cooled to 40°C and charged with 500 mL hexane. The activated
catalyst mixture made above was transferred to the reactor by nitrogen
over pressure. The reactor was sealed and the temperature was
brought to 60°C. Ethylene (C2=) and propylene (C3=) gases (C2=/C3=
fill ratio = 1:1) were charged to the reactor until the reactor pressure
reached 90 psi (0.62 MPa). The ratio of the gases was then adjusted to
C2=/C3= = 0.33. The polymerization was carried out for 1 hour after
the introduction of the monomer gases. ENB (0.5 mL) was injected to
the reactor under pressure at polymerization time of 10 min and 30
min. Therefore 3 mL total ENB was charged to the reactor.
Polymerization was terminated by injecting 2 mL of ethanol
killing solution (0.5 g BHT, 1.0 g Kemamine, 0.5 g Irganox in 125 mL
of ethanol). The C2- and C3= gases wei'e.shut down and the reactor
was vented and cooled to room temperature. ,,The polymer was scooped
out, blended in methanol and dried in a vacuuni~oven at 40°C
overnight. The collected polymer weighed 59.7 g, for catalyst activity
of 15.5 kg(EPDM)/mmol Ti/hr. The polymer had FI = 1.32 and a P.R.T
of -26.2°C.
Example 10.
In a glove box under nitrogen, a small oven-dried glass vial was
charged with magnetic stir bar and 0.024 g (C5Me5)Ti(02CCMe3)3.
This vial was sealed and brought out of the glove box. Toluene (5 mL)
was added to the vial to form a solution with a concentration of 0.01
mol/L. In another oven-dried glass vial sealed under nitrogen, 0.05 mL
methanol was mixed with 10 mL toluene resulting in a 0.123 mol/L
D-17901
CA 02338767 2001-O1-25
-31-
concentration MeOH/toluene solution. In a third small oven dried glass
vial, 2.06 g of 2,6-di-t-butylphenol (DTBP) and 20 mL toluene were
added under nitrogen to form a DTBP/toluene solution. with
concentration of 0.5 mol/L.
A small oven dried glass vial with a stir bar was sealed under
nitrogen. To this vial, 0.5 mL of (C5Me5)Ti(02CCMe3)3/toluene
solution (0.005 mmol Ti) and 0.16 mL of MeOH/toluene solution were
mixed at room temperature for 60 minutes (MeOH/Ti = 4).
A 100 mL glass oven-dried bottle with a stir bar was sealed with
a septum and purged with nitrogen. To this bottle the following
components were added under nitrogen: 50 mL of hexane; 0.30 mL
MAO (3.36 mol/L in toluene); 1.0 mL of DTBP/toluene solution; 0.66
mL of (C5Me5)Ti(02CCMe3)3/MeOH mixture made above and 2 mL of
ENB. In this bottle the final active catalyst was formed with ratios of
DTBP/Ti = 100, MeOH/Ti = 4, MAO/Ti = 200.
The 1L stainless-steel Fluitron reactor was baked for one hour
at 100°C with nitrogen constantly flowihg through it. It was then
cooled to 40°C and charged with 500 mL hexane. The activated
catalyst mixture made above was transferred to'the reactor by nitrogen
over pressure. The reactor was sealed and the temperature was
brought to 60°C. Ethylene (Cp=) and propylene (C3=) gases (C2=/C3=
fill ratio = 1:1) were char~:ed to the reactor until the reactor pressure
reached 90 psi (0.62 AlPa). The ratio of the gases was then adjusted to
C2=/C3= = 0.33. The polymerization was carried out for 1 hour after
the introduction of the monomer gases. ENB (0.5 mL) was injected to
the reactor under pressure at polymerization time of 10 min and 30
min. Therefore 3 mL total ENB was charged to the reactor.
Polymerization was terminated by injecting 2 mL of ethanol
killing solution (0.5 g BHT, l.Og Kemamine, 0.5 g Irganox in 125 mL of
ethanol). The C2= and Cg= gases were shut down and the reactor was
CA 02338767 2001-O1-25
D-17901
-32-
vented and cooled to room temperature. The polymer was scooped out,
blended in methanol and dried in a vacuum oven at 40°C overnight.
The collected polymer weighed 34.1 g, for catalyst activity of 6.82
kg(EPDM)/mmol Ti/hr. The polymer contained 51.2 wt % propylene
and 4.5 wt % ENB. The polymer had FI = 1.6 and no PRT
Example 11.
An experiment similar to Example 10 was conducted except that
0.57 mL MMAO (1.74 mol(Al)/L in heptane) was used in place of MAO.
The final active catalyst was formed with ratios of DTBP/Ti = 100,
MeOH/Ti = 4, MMAO/Ti = 200.
The collected polymer weighed 26.2 g, for catalyst activity of
5.24 kg(EPDM)/mmol Ti/hr. The polymer did not flow because of high
molecular weight.
Comparative Example 1. '
A similar experiment as Example,6 was carried out except that
(C5Me5)TiClg precursor instead of (C5Me5)Ti(02CPh)g was used.
After polymerization only 0.8 g of polymer was-collected. This
experiment shows that (C5Me5)TiClg is not active with MMAO
cocatalyst for EPDM polymerization at a high aluminumaitanium
ratio.
Comparative Example 2.
A similar experiment as Comparative Example 1 was carried out
except that the aluminumaitanium molar ratio was only 200:1. After
polymerization 44.5 g of polymer was collected for a catalyst activity of
8.90 kg(EPDM)/mmol Ti/hr. The polymer had FI = 0.44 and a PRT of
-34.8°C.
