Note: Descriptions are shown in the official language in which they were submitted.
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SUPPORTED CATALYST COMPONENT, SUPPORTED CATALYST,
THEIR PREPARATION, AND ADDITION POLYMERIZATION PROCESS
The present invention relates to a supported catalyst component comprising a
5 support material and alumoxane, to a supported catalyst col.lpr i,i, lg a support material,
alumoxane, and a metallocene compound, to a process for preparing such a supported catalyst
component and catalyst, and to an addition polymerization process using such a supported
catalyst.
Backqround of the Invention
Homogeneous or non-supported alumoxane metallocene catalysts are known for
their high catalytic activity in olefin polymerizations. Under polymerization conditions where
polymer is formed as solid particles, these homogeneous (soluble) catalysts form deposits of
polymer on reactor walls and stirrers, which deposits should be removed frequently as they
prevent an efficient heat-exchange, necessary for cool ing the reactor contents, and cause
excessive wear of the moving parts. The polymers produced by these soluble catalysts further
have a low bulk density which limits the commercial utility of both the polymer and the
process. In order to solve these problems, several supported alumoxane metallocene catalysts
have been proposed for use in particle forming polymerization processes.
U.S. Patent 5,057,475 describes a supported metallocene alumoxane catalyst
20 wherein the alumoxane can be a commercial alumoxane, or an alumoxane generdted in situ on
the solid support, for example, by the addition of a trialkylaluminum compound to a water-
containing support, such as by addition of trimethylaluminum to a water containing silica. In
the prerer,ed methods of U.S. Patent 5,057,475, the metallocene component and the
alumoxane (which previously may have been combined with a modifier compound) are25 combined in a first step in a suitable solvent. In a subsequent step, this solution is contacted
with the support. Then, the solvent can be removed, typically by applying a vacuum. The
solution may be heated in order to aid in the removal of the solvent. In an alternative method,
an undehydrated silica gel is added to a solution of trialkylaluminum to produce an alumoxane
which is deposited onto the surface of the silica gel particles. Then, the solvent is removed and
30 the residual solids are dried to a free-flowing powder. In typical examples, dried silica is
slurried with an alumoxane in toluene, filtered, washed with pentane, and then dried under
vacuum. The metallocene compound is typically combined with an alumoxane in toluene or
heptane, which solution subsequently is combined with the pretreated silica. Finally, the
toluene or heptane is removed under vacuum to recover the supported catalyst.
U.S. Patent 5,026,797 describes treating a porous water-insoluble inorganic oxide
particle support with an alumoxane in a solvent for the alumoxane, such as an aromatic
hydrocarbon, followed by rinsing the treated support with an aromatic hydrocarbon solvent
until no alumoxane is detected in the supernatant. Thus, it is said to be possible to adiust the
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amount of the aluminum atom of the alumoxane bonded onto the treated oxide support in
the range of 2 to 10 percent by weight. Subsequently, the treated support is combined with a
zirconium compound. The so-formed support material containing alumoxane and zirconium
compound is used together with additional alumoxane in solution in a polymel i~d li
5 reaction.
U.S. Patent 5,147,949 discloses supported metallocene alumoxane catalysts
prepared by adding a water-impregnated catalyst support to a stirred solution of an aluminum
trialkyl, and adding to the reaction productthereof a metallocene component.
U.S. Patent 5,240,894 describes a method to produce a supported catalyst by
10 forming a metallocene/alumoxane reaction solution, adding a porous carrier, evaporating the
resulting slurry so as to remove residual solvent from the carrier, and optionally
prepolymerizing the catalyst with olefinic monomer. A good polymer bulk density is only
obtained using a prepolymerized supported catalyst.
U.S. Patent 5,252,529 discloses solid catalysts for olefin polymerization comprising
a particulate carrier containing at least one percent by weight of water, an alumoxane
compound, and a metallocene compound. In the preparation of this catalyst, the reaction
product of the particulate carrier and the alumoxane is separated from the diluent (toluene) by
decantation or drying at reduced pressure.
European Patent Application No. 368,644 discloses a process for preparing a
20 supported metallocene alumoxane catalyst wherein an undehydrated silica gel is added to a
stirred solution of triethylaluminum, to which reaction mixture is added a solution of a
metallocene to which trimethylaluminum has been added. Following the addition of the
trimethylaluminum treated metallocene to the triethylaluminum treated silica gel solids, the
catalyst is dried to a free-flowing powder. Drying of the catalyst may be done by filtration or
25 evaporation of solvent at a temperature up to 85C.
European PatentApplication No.323,716 discloses a process for preparing a
supported metallocene alumoxane catalyst by adding undehydrated silica gel to a stirred
solution of an aluminum trialkyl, adding a metallocene to the reacted mixture, removing the
solvent, and drying the solids to a free-flowing powder. After the metallocene has been
30 added, the solvent is removed and the residual solids are dried at a temperature of up to 85C.
European Patent Application No. 523,416 describes a supported catalyst
component for olefin polymerization prepared from an inorganic support and a metallocene.
The metallocene and support are intensively mixed in a solvent. P~ ererdbly, the catalyst
component thus obtained is extracted in a suitable solvent, such as toluene, to remove
35 metallocene which is not fixed. Subsequently, alumoxane can be added as a cocatalyst.
European Patent Application No. 567,952 describes a supported polymerization
catalyst comprising the reaction product of a supported organoaluminum compound and a
metallocene catalyst compound. This supported catalyst is prepared by combining
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trimethylaluminum with a previously dried support material in an aliphatic inert suspension
medium, to which water is added. This suspension can be used as such or can be filtered and
the solids thus obtained can be resuspended in an aliphatic inert suspension medium, and then
combined with the metallocene compound. When the reaction is complete, the su~,e. "dldnt
5 solution is separated off and the solid which remains is washed once to five times with an inert
suspending medium, such as toluene, n-decane, diesel oil or dichloromethane.
It would be desirable to provide a supported catalyst component, a supported
catalyst, and a polymerization process that pr_ le. ~l~ or sul"ldnlially reduces the problem of
reactor fouling, including formation of polymer deposits on reactor walls and on the agitator
10 in the reactor, especially in gas phase polymerization or slurry polymerization processes.
Further, it is preferred that polymer products produced by gas phase polymerization or slurry
polymerization processes are in free-flowing form and, advantageously, have high bulk
densities.
Summarv of the Invention
In one aspect of the present invention, there is provided a supported catalyst
component comprising a support material and an alumoxane, which component contains 15 to
40 weight percent of aluminum, based on the total weight of the support material and
alumoxane, and wherein not more than 10 percent aluminum present in the supported catalyst
component is extractable in a one-hour extraction with toluene of 90C using 10 mL toluene
20 per gram of supported catalyst component, said supported catalyst component being
obtainable by
A. heating a support material containing alumoxane under an inert
atmosphere for a period and at a temperature sufficient to fix alumoxane to the support
material.
In a second aspect, there is provided a supported catalyst comprising: the
supported catalyst component according to the present invention and a transition metal
compound containing at least one cyclic or noncyclic n-bonded anionic ligand group.
According to a further aspect, there is provided a process for preparing a
supported catalyst component comprising:
A. heating a support material containing alumoxane under an inert
atmosphere for a period and at a temperature sufficient to fix alumoxane to the support
material;
thereby selecting the conditions in heating step A so as to form a supported
catalyst component, which component contains 15 to 40 weight percent of aluminum, based
35 on the total weight of the support material and alumoxane, and wherein not more than 10
percent aluminum present in the supported catalyst component is extractable in a one-hour
extraction with toluene of 90C using 10 mL toluene per gram of supported catalyst
component.
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In another aspect, the invention provides a process for preparing a supported
catalyst comprising:
A. heating a support materiai containing alumoxane under an inert
atmosphere for a period and at a temperature sufficient to fix alumoxane to the support
5 material; and optionallyfollowed by
B. subjecting the support material containing alumoxane to one or more
wash steps to remove alumoxane not fixed to the support material;
thereby selecting the conditions in heating step A and optional washing step B so
as to form a supported catalyst component, which component contains 15 to 40 weight percent
10 of aluminum, based on the total weight of the support material and alumoxane, and wherein
not more than 10 percent aluminum present in the supported catalyst component isextractable in a one-hour extraction with toluene of 90C using 10 mL toluene per gram of
supported catalyst component; and
adding, before or after step A or step B, a l, dn,ilion metal compound containing
15 at least one cyclic or noncyclic n-bonded an ionic ligand group, with the proviso that once the
transition metal compound has been added, the product thus obtained is not subjected to
temperatures equal to or higherthan the decomposition temperature of the lrdn~ilion metal
compound.
In yet a further aspect, there is provided an addition polymerization process
20 wherein one or more addition polymerizable monomers are contacted with a supported
catalyst according to the present invention under addition polymerizable conditions.
Detailed Descri,otion of the Invention
All references herein to elements or metals belonging to a certain 6roup refer to
the Periodic Table of the Elements published and copyrighted by CRC Press, Inc., 1989. Also,
25 any reference to the Group or Groups shall be to the Group or Groups as reflected in this
Periodic Table of the Elements using the IUPAC system for numbering groups. The term
hydrocarbyl as employed herein means any aliphatic, cycloaliphatic, aromatic group or any
combination thereof. The term hydrocarbyloxy means a hydrocarbyl group having an oxygen
link between it and the element to which it is attached. Where in the specification and claims
30 the expression "substituted cyclopentadienyl" is used, this includes ring-substituted or
polynuclear derivatives of the cyclopentadienyl moiety wherein said substituent is hydrocarbyl,
hydrocarbyloxy, hydrocarbylamino, cyano, halo, silyl, germyl, siloxy or mixtures thereof or two
such substituents are a hydrocarbylene group, said substituent (or two substituents together)
having up to 30 non-hydrogen atoms. By the term "substituted cyclopentadienyl" is specifically
35 included indenyl, tetrahydroindenyl, fluorenyl, and octahydrofluorenyl groups.
Surprisingly, it has been found that polymers having good bulk density can be
prepared in a particle forming polymerization process, without or with substantially reduced
reactor fouling, by using a supported catalyst wherein the alumoxane is fixed to the support
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material. According to the present invention, good bulk densities, for ethylene based polymers
and interpolymers, are bulk densities of at least 0.20 g/cm3, preferably of at least 0.25 g/cm3,
and more preferably of at least 0.30 g/cm3. It is believed that the extent of reactor fouling is
- related to the amount of alumoxane which leaches off the support during polymerization
5 conditions, which may lead to active catalyst being present in the homogeneous phase, thus
disso!ved in the di!uent, which under particle forming condi.ions may give very smaii poiymer
parlicles or polymer particles of poor morphology that may adhere to metal parts or static parts
in the reactor. Further, it is believed that the bulk density of a polymer is related to the manner
in which alumoxane is fixed to the support and to the amount of non-fixed alumoxane on the
10 support, that is, the amount of aluminum that can be extracted from the support by toluene of
90C. The fixation of the alumoxane on the support according to the specific treatment of the
present invention results in substantially no alumoxane being leached off of the support under
polymerization conditions and substantially no soluble active catalyst species being present in
the polymerization mixture. It has been found that the present supported catalysts can be used
15 not only to prepare ethylene polymers and copolymers in the traditional high density
polyethylene density range (0.970 to 0.940 g/cm3) in slurry and gas phase polymerization
processes, but also copolymers having densilies lower than 0.940 g/cm3 down to 0.880 g/cm3 or
lower while reta ining good bulk density properties and while preventing or substantially
decreasing reactorfouling.
The supported catalyst component of the present invention comprises a support
material and an alumoxane wherein in general not more than 10 percent aluminum present in
the supported catalyst component is exllacldble in a one-hour extraction with toluene of 90C
using 10 mL toluene per gram of supported catalyst component. P-ereral)ly, not more than 9
percent aluminum present in the supported catalyst component is extractable, and most
25 preferably not more than 8 percent. It has been found that when the amount of extractables is
below these levels, a good polymer bulk density is obtained with supported catalysts based on
these supported catalyst components.
The toluene extraction test is carried out as follows. 1 g of supported catalystcomponentorsupportedcatalyst,withaknownaluminumcontent,isaddedto10mLtoluene
30 and the mixture is then heated to 90C under an inert atmosphere. The suspension is stirred
well at this temperature for 1 hour. Then, the suspension is filtered applying reduced pressure
to assist in the filtration step. The solids are washed twice with 3 to 5 mL toluene of 90C per
gram of solids. The solids are then dried at 1 20C for 1 hour, and subsequently the aluminum
content of the solids is measured. The difference between the initial aluminum content and
35 the aluminum content after the extraction divided by the initial aluminum content and
multiplied by 100 percent, gives the amount of extractable aluminum.
The aluminum content is determined by slurrying 0.5 g of supported catalyst
componentorsupportedcatalystin10mLhexane. Theslurryistreatedwith10to15mL6N
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sulfuric acid, followed by addition of a known excess of EDTA. The excess amount of EDTA is
then back-titrated with zinc chloride.
At a ievel of 10 percent extractables, the polymer bulk density obtained by
polymerization using supported catalysts (components) described herein is quite sensitive with
5 respect to small changes in the percentage of aluminum extractables. In view of the sensitivity
of the polymer bulk density and the error margin in the determination of the pe. cen Ldge
aluminum extractables (which is estimated to be 1 percent absolute), an alternative test to
distinguish the supported catalyst component and supported catalyst according to the present
invention is to use a supported catalyst in an ethylene polymerization process in a hydrocarbon
10 diluent at 80C and 15 bar and determine the extent of reactor fouling and/or the bulk density
of the ethylene polymer produced. The suL~ldnlial absence of reactor fouling, that is,
substantially no polymer deposits on reactor walls or agitator, and/or bulk densities of at least
0.20 g/cm3, and preferably of at least 0.25 g/cm3, are characteristic of the inventive supported
catalyst components and catalysts.
Support materials suitable for the present invention preferably have a surface
area as determined by nitrogen porosimetry using the B.E.T. method from 10 to 1000 m2/g, and
preferdbly from 100 to 600 m2/g. The porosity of the support advantageously is between 0.1
and 5 cm3/g, preferably from 0.1 to 3 cm3/g, most preferably from 0.2 to 2 cm3/g. The average
particle size is not critical but typically from 1 to 200 I m.
Suitable support materials for the supported catalyst component of the present
invention include porous resinous materials, for example, copolymers of styrene-divinylbenzene, and solid inorganic oxides, such as silica, alumina, magnesium oxide, titanium
oxide, thorium oxide, as well as mixed oxides of silica and one or more Group 2 or 13 metal
oxides, such as silica-magnesia and silica-alumina mixed oxides. Silica, alumina, and mixed
25 oxides of silica and one or more Group 2 or 13 metal oxides are preferred support materials.
Preferred examples of such mixed oxides are the silica-aluminas. Most preferred is silica. The
silica may be in granular, agglomerated, fumed or otherform. Suitable silicas include those
that are available from Grace Davison (division of W.R. Grace & Co.) under the designations SD
3216.30, Davison Syloid 245, Davison 948 and Davison 952, and from Degussa AG under the
30 designation Aerosil 812.
Prior to its use, if desired, the support material may be subjected to a heat
treatment and/or chemical treatment to reduce the water content or the hydroxyl content of
the support material. Typical thermal pretreatments are carried out at a temperature from
30C to 1 000C for a duration of 10 minutes to 50 hours in an inert atmosphere or under
35 reduced pressure.
The supported catalyst component further comprises an alumoxane component.
An alumoxane (also referred to as aluminoxane) is an oligomeric or polymeric aluminum oxy
compound containing chains of alternating aluminum and oxygen atoms, wherebythe
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aluminum carries a substituent, pl efel dbly an alkyl group. The exact structure of alumoxane is
not known, but is generally believed to be rep~esented by the following general formulae (-
AI(R)-O)m, for a cyclic alumoxane, and R2Al-o(-Al(R)-o)m-AlR2l for a linear compound, wherein
- R independently each occurrence is a C1 to C10 hydrocarbyl, preferably alkyl, or halide and m is
5 an integer ranging from 1 to 50, p~ efel dbly at least 4. Al umoxanes are typically the reaction
products of water and an aluminum alkyl, which in addition to an alkyl group may contain
halide or alkoxide groups. Reacting several different aluminum alkyl compounds, such as, for
example, trimethylaluminum and tri-isobutyl aluminum, with water yields so-called modified
or mixed alumoxanes. P~ efe~ ~ ~d alumoxanes are methylalumoxane and methylalumoxane
10 modified with minor amounts of other lower alkyl groups such as isobutyl. Alumoxanes
generally contain minor to substantial amounts of starting aluminum alkyl compound.
The way in which the alumoxane is prepared is not critica I for the present
invention. When prepared by the reaction between water and aluminum alkyl, the water may
be combined with the aluminum alkyl in various forms, such as liquid, vapor, or solid, for
15 example, in the form of water of crystallization. Particular techniques for the preparation of
alumoxane-type compounds by contacting an aluminum alkyl compound with an inorganic salt
containing water of crystallization are disclosed in U.S. Patent 4,542,199. In a particular
p, efel . ed embodiment, an aluminum alkyl compound is contacted with a regeneratable water-
containing substance such as hydrated alumina, silica or other substance. This is disclosed in
20 European PatentApplication No. 338,044.
The supported catalyst component of the present invention generally contains 15
to 40 weight percent, preferably from 20 to 40 weight percent, and more preferdbly from 25 to
40 weight percent of aluminum, based on the total weight of the support material and
alumoxane. Amounts of aluminum of at least 15 weight percent, preferdbly at least 20 weight
25 percent, and most preferably at least 25 weight percent are advantageous because these
enable the deposit of relatively high amounts of transition metal compound on the support
and thereby enable a relatively high activity to be obtained. This improves the overall catalyst
efficiency, especially when expressed on the basis of the support material.
The supported catalyst component as such or slurried in a diluent can be stored or
30 shipped under inert conditions, or can be used to generate the supported catalyst of the
present invention.
According to a further aspect, the present invention provides a supported catalyst
comprising the supported catalyst component according to the present invention and a
transition metal compound, preferably a transition metal compound containing at least one
35 cyclic or non-cyclic n-bonded anionic ligand group, preferably a cyclopentadienyl or substituted
cyclopentadienyl moiety. Suitable complexes are derivatives of any transition metal including
Lanthanides, but preferably of 6roup 3, 4, 5, or Lanthanide metals which are in the + 2, + 3, or
+4 formal oxidation state. P~ efer,ed compounds include metal complexes containing from 1
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to 3 n-bonded anionic ligand groups, which may be cyclic or non-yclic delocalized n-bonded
anionic ligand groups. Exemplary of such n-bonded anionic ligand groups are conjugated or
nonconjugated, cyclic or non-yclic dienyl groups, allyl groups, and arene groups. By the term
"n-bonded " is meant that the ligand group is bonded to the transition metal by means of a n
5 bond. Each atom in the delocalized n-bonded group may independently be substituted with a
radical selected from halogen, hydrocarbyl, halohydrocarbyl, and hydrocarbyl-substituted
metalloid radicals wherein the metalloid is selected from Group 14 of the Periodic Table of the
Elements. Included within the term hydrocarbyl are preferably C1 20 straight, branched and
cyclic alkyl radicals, C6 20 aromatic radicals, C7 20 alkyl-substituted aromatic radicals, and C7 20
10 aryl-substituted alkyl radicals. In addition two or more such radicals may together form a fused
ring system or a hydrogenated fused ring system. Suitable hy.l~ .carbyl-substituted
organometalloid radicals include mono-, di- and trisubstituted organometalloid radicals of
Group 14 elements wherein each of the hydrocarbyl groups contains from 1 to 20 carbon
atoms. Examples of suitable hydrocarbyl-substituted organometalloid radicals include
15 trimethylsilyl, triethylsilyl, ethyldimethylsilyl, methyldiethylsilyl, triphenylgermyl, and
trimethylgermyl groups.
Examples of suitable anionic, delocalized n-bonded groups include
yclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorenyl,
octahydrofluorenyl, pentadienyl, yclohexadienyl, dihydroanthracenyl, hexahydroanthracenyl,
20 and decahydroanthracenyl groups, as well as C1-10 hydrocarbyl-substituted derivatives thereof.
Preferred anionic delocalized n-bonded groups are yclopentadienyl,
pentamethylcyclopentadienyl, tetramethylyclopentadienyl, indenyl, 2,3-dimethylindenyl,
fluorenyl, 2-methylindenyl and 2-methyl-4-phenylindenyl.
The term metallocene compound as used herein refers to transition metal
25 compounds containing a derivative of a cyclopentadienyl moiety. Suitable metallocenes for
use in the present invention are the bridged or unbridged mono-, bis-, and triyclopentadienyl
or substituted yclopentadienyl transition metal compounds.
Suitable unbridged monocyclopentadienyl or mono(substituted
yclopentadienyl) transition metal derivatives are represented by the general formula CpMXn
30 wherein Cp is cyclopentadienyl or a derivative thereof; M is a Group 3, 4, or 5 transition metal
having a formal oxidation state of 2, 3 or 4; X independently each occurrence represents an
anionic ligand group (otherthan a cyclic, aromatic n-bonded anionic ligand group), said X
having up to 50 non-hydrogen atoms; and n, a number equal to one less than the formal
oxidation state of M, is 1, 2 or 3, preferably 3. Exemplary of such ligand groups X are
35 hydrocarbyl, hydrocarbyloxy, hydride, halo, silyl, germyl, amide, and siloxy or two X groups
together mayform a hydrocarbylene (including hydrocarbylidene).
Suitable bridged monocyclopentadienyl or mono(substituted yclopentadienyl)
transition metal compounds include the well-known constrained geometry complexes.
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Examples of such complexes and methods for their preparation are disclosed in U.S. Application
Serial No. 545,403, filed July 3, 1990 (corresponding to EP-A-416,815), U.S. Patent 5,374,696
(corresponding to WO-93/19104), as well as U.S. Patents 5,055,438, 5,057,475, 5,096,867,
- 5,064,802 and 5,132,380.
More particularly, pr~r~r. ed bridged monocyclopentadienyl or mono(substituted
cyclopentadienyl) transition metal compounds correspond to the formula l:
Cp* M
(X)n
wherein:
M is a metal of Group 3 to 5, especially a Group 4 metal, particularly titanium;Cp* is a substituted cyclopentadienyl group bound to Z' and, in an rlS bonding
mode, to M or such a group is further substituted with from one to four substituents selected
from hydrocarbyl, silyl, germyl, halo, hydrocarbyloxy, amino, and mixtures thereof, said
substituent having up to 20 non-hydrogen atoms, or optionally, two such further substituents
(except halo or amino) together cause Cp* to have a fused ring structure;
Z' is a divalent moiety other than a cyclic or non-cyclic n-bonded anionic ligand,
said Z' comprising boron, or a member of Group 14 of the Periodic Table of the Elements, and
optionally nitrogen, phosphorus, sulfur or oxygen, said moiety having up to 20 non-hydrogen
atoms, and optionally Cp* and Z' togetherform a fused ring system;
X independently each occurrence is an anionic ligand group (other than a cyclic n-
bonded group) having up to 50 non-hydrogen atoms; and
n is 1 or 2 depending on the valence of M.
In consonance with the previous explanation, M is prererdbly a Group 4 metal,
especially titanium; n is 1 or 2; and X is a monovalent ligand group of up to 30 non-hydrogen
atoms, more preferably, C1-20 hydrocarbyl.
When n is 1 and the Group 3 to 5 metal (preferably the Group 4 metal) is in the
+3 formal oxidation state, X is preferably a stabilizing ligand.
By the term "stabilizing ligand" is meant that the ligand group stabilizes the
metal complex through either:
1) a nitrogen, phosphorus, oxygen or sulfur chelating bond, or
2) an rl3 bond with a resonant, delocalized n-electronic structure.
Examples of stabilizing ligands of group 1 include silyl, hydrocarbyl, amido or
phosphido ligands substituted with one or more aliphatic or aromatic ether, thioether, amine
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or phosphine functional groups, especially such amine or phosphine groups that are tertiary
substituted, said stabilizing ligand having from 3 to 30 non-hydrogen atoms. Most pref~r, ed
group 1 stabilizing ligands are 2-dialkylaminobenzyl or 2-(dialkylaminomethyl)phenyl groups
containing from 1 to 4 carbons in the alkyl groups.
Examples of stabilizing ligands of group 2 include C3 10 hydrocarbyl groups
containing ethylenic unsaturation, such as allyl, 1-methylallyl, 2-methylallyl, 1,1-dimethylallyl,
or 1,2,3-trimethylallyl groups.
More preferably still, such metal coordination complexes cur, ~" ond to the
formula ll:
R ' z
~ Y
R~<O I M/ II
'f R ~ ~X)n
R~
wherein R' each occurrence is independently selected from hydrogen,
hydrocarbyl, silyl, germyl, cyano, halo and combinations thereof having up to 20 non-hydrogen
atoms, or two R' groups (except cyano or halo) together form a divalent derivative thereof;
X each occurrence independently is selected from hydride, halo, alkyl, aryl, silyl,
20 germyl, aryloxy, alkoxy, amide, siloxy, and combinations thereof having up to 20 non-hydrogen
atoms;
Y is a divalent anionic ligand group comprising nitrogen, phosphorus, oxygen or
sulfur and having up to 20 non-hydrogen atoms, said Y being bonded to Z and M through said
nitrogen, phosphorus, oxygen or sulfur, and optionally Y and Z together form a fused ring
25 system;
M is a Group 4 metal, especiallytitanium;
Z is SiR*2, CR*2, SiR*2SiR*2, CR*2CR*2, CR* = CR*, CR*ZsiR*2~ GeR*2, BR*, or BR*2;
wherein:
R* each occurrence is independently selected from hydrogen, hydrocarbyl, silyl,
30 halogenated alkyl, halogenated aryl groups having up to 20 non-hydrogen atoms, and
mixtures thereof, or two or more R* groups from Z, or an R* group from Z together with Y
form a fused ring system; and
n is 1 or 2.
Further more preferably, Y is-O-, -S-, -NR*-, -PR*-. Highly preferably, Y is a
3 nitrogen or phosphorus containing group corresponding to the formula -N(R')- or -P(R')-,
wherein R' is as previously described, that is, an amido or phosphido group.
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Most highly prefer. ed metal coordination complexes correspond to the formula
111:
R~ (ER 2)m~N R~
S R~/ M III
R~ (X)n
R
wherein:
M istitanium;
R' each occurrence is independently selected from hydrogen, silyl, hydrocarbyl
andcombinationsthereofhavingupto20,prererdblyuptolOcarbonorsiliconatoms,ortwo
R' groups of the substituted cyclopentadienyl moiety are joined together;
E is silicon or carbon;
X independently each occurrence is hydride, halo, alkyl, aryl, aryloxy or alkoxy of
up to 10 carbons;
m is 1 or 2; and
nis1 or2.
Examples of the above most highly prer~r.ed metal coordination compounds
20 include compounds wherein the R' on the amido group is methyl, ethyl, propyl, butyl, pentyl,
hexyl (including isomers), norbornyl, benzyl, phenyl or cyclododecyl; (ER'z)m is dimethyl silane
or 1 ,2-ethylene; R' on the cyclic n-bound group independently each occurrence is hydrogen,
methyl, ethyl, propyl, butyl, pentyl, hexyl, norbornyl, benzyl or phenyl or two R' groups are
joined forming an indenyl, tetrahydroindenyl, fluorenyl or octahydrofluorenyl moiety; and X is5 chloro, bromo, iodo, methyl, ethyl, propyl, butyl, pentyl, hexyl, norbornyl, benzyl or pheny
l.
Specific highly prerer-ed compounds include: (tert-butylamido)(tetramethyl-rl5-
cyclopentadienyl)-1,2-ethanediyltitanium dimethyl, (tert-butylamido)(tetramethyl-rl5-
cyclopentadienyl)-1,2-ethanediyltitanium dibenzyl, (tert-butylamido)(tetramethyl-
rl5-cyclopentadienyl)dimethylsilanetitanium dimethyl, (tert-butylamido)(tetramethyl-
30 rl5-cyclopentadienyl)dimethylsilanetitanium dibenzyl, (methylamido)(tetramethyl-rl5-
cyclopentadienyl)dimethylsilanetitanium dimethyl, (methylamido)(tetramethyl-rl5-cyclopenta-
dienyl)dimethylsilanetitanium dibenzyl, (phenylamido)(tetramethyl-rl5-cyclopenta-
dienyl)dimethylsilanetitanium dimethyl, (phenylamido)(tetramethyl-rl5-cyclopenta-
dienyl)dimethylsilanetitanium dibenzyl, (benzylamido)(tetramethyl-rl5-cyclopenta-
35 dienyl)dimethylsilanetitanium dimethyl, (benzylamido)(tetramethyl-rl5-cyclopenta-
dienyl)dimethylsilanetitanium dibenzyl, (tert-butylamido)(rl5-cyclopentadienyl)-1,2-ethanediyltitanium dimethyl, (tert-butylamido)(r~5-cyclopentadienyl)-
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1,2-ethanediyltitanium dibenzyl, (tert-butylamido)(~5-cyclopentadienyl)-
dimethylsilanetitanium dimethyl, (tert-butylamido)(rl5-cyclopentadienyl)dimethyl-
silanetitanium dibenzyl, (methylamido)(rl5-cyclopentadienyl)dimethylsilanetitanium dimethyl,
(t-butylamido)(rl5-cyclopentadienyl)dimethylsilanetitanium dibenzyl, (t-
5 butylamido)indenyldimethylsilanetitanium dimethyl, (t-butylamido)indenyldimethylsilane-
titanium dibenzyl, (benzylamido)indenyldimethylsilanetitanium dibenzyl; and the
cor.e".onding zirconium orhafnium coordination complexes.
Transition metal compounds wherein the l,ansilion metal is in the + 2 formal
oxidation state and processes for their preparation are disclosed in detail in WO 9500526 which
10 corresponds to U.S. Application Serial No. 241,523, filed May 12,1994. Suitable complexes
include those containing one, and only one, cyclic, delocalized, anionic, n-bonded group, said
complexes corresponding to the formula lV:
z
IV
L M--X*
wherein:
M is titanium or zirconium in the + 2 formal oxidation state;
L is a group containing a cyclic, delocalized, anionic, n-system through which the
group is bound to M, and which group is also bound to Z;
Z is a moiety bound to M via a a-bond, comprising boron, or a member of Group
14 of the Periodic Table of the Elements, and also comprising nitrogen, phosphorus, sulfur or
oxygen, said moiety having up to 60 non-hydrogen atoms; and
X* is a neutral, conjugated or non-conjugated diene, optionally substituted withone or more hydrocarbyl groups, said X having up to 40 carbon atoms and forming a n-complex
with M.
Preferred transition metal compounds of formula IV include those wherein Z, M
and X* are as previously defined; and L is a C5H4 group bound to Z and bound in an rl5 bonding
mode to M or is such an rl5 bound group substituted with from one to four substituents
independently selected from hydrocarbyl, silyl, germyl, halo, cyano, and combinations thereof,
said substituent having up to 20 non-hydrogen atoms, and optionally, two such substituents
(except cyano or halo) together cause L to have a fused ring structure.
More preferred transition metal + 2 compounds according to the present
invention correspond to the formula V:
R' Z~
R ~,~ M V
R~ X*
R
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wherein:
R' each occurrence is independently selected from hydrogen, hydrocarbyl, silyl,
germyl, halo, cyano, and combinations thereof, said R' having up to 20 non-hydrogen atoms,
- and optionally, two R' groups (where R' is not hydrogen, halo or cyano) together form a
5 divalent derivative thereof connected to adjacent positions of the cycloper,lddienyi ring to
form a fused ring structure;
X* is a neutral rlAbonded diene group having up to 30 non-hydrogen atoms,
which forms a n-complex with M;
Y is-O-,-S-,-NR*-, -PR*-;
M is titanium or zirconium in the + 2 formal oxidation state; and
Z* is SiR*z, CR*z, SiR*2SiR*2, CR*2CR*z, CR*=CR*, CR*2SiR*2, or GeR*2; wherein:
R* each occurrence is independently hydrogen, or a member selected from
hydrocarbyl, silyl, halogenated alkyl, halogenated aryl, and combinations thereof, said R*
having up to 10 non-hydrogen atoms, and optionally, two R* groups from Z* (when R* is not
15 hydrogen), or an R* group from Z* and an R* group from Y form a ring system.
P~ eferdbly, R' independently each occurrence is hydrogen, hydrocarbyl, silyl, halo
and combinations thereof said R' having up to 10 non-hydrogen atoms, or two R' groups (when
R' is not hydrogen or halo) together form a divalent derivative thereof; most prererdbly, R' is
hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, (including where appropriate all isomers),
20 cy~lopenlyl, cyclohexyl, norbornyl, benzyl, or phenyl ortwo R' groups (except hydrogen) are
linked together, the entire CsR'4 group thereby being, for example, an indenyl,
tetrahydroindenyl, fluorenyl, tetrahydrofluorenyl, or octahydrofluorenyl group.
Further preferdbly, at least one of R' or R* is an electron donating moiety. By the
term "electron donating" is meant that the moiety is more electron donating than hydrogen.
25 Thus, highly preferably Y is a nitrogen or phosphorus containing group corresponding to the
formula -N(R")- or-P(R")-, wherein R" is C1 10 hydrocarbyl.
Examples of suitable X* groups include: s-trans-rl4-1,4-diphenyl-1,3-butadiene; s-
trans-rl4-3-methyl-1 ,3-pentadiene; s-trans-rl4-1 ,4-dibenzyl-1 ,3-butadiene; s-trans-rl4-2,4
hexadiene; s-trans-rl4-1,3-pentadiene; s-trans-rl4-1,4-ditolyl-1,3-butadiene; s-trans-rl4-1,4-
30 bis(trimethylsilyl)-1,3-butadiene; s-cis-rl4-1,4-diphenyl-1,3-butadiene; s-cis-rl4-3-methyl-
1,3-pentadiene; s-cis-rl4-1,4-dibenzyl-1,3-butadiene; s-cis-rl4-2,4-hexadiene; s-cis-rl4-1,3-
pentadiene; s-cis-rl4-1,4-ditolyl-1,3-butadiene; and s-cis-rl4-1,4-bis(trimethylsilyl)-1,3-
butadiene, said s-cis diene group forming a n-complex as defined herein with the metal.
Most highly preferred transition metal +Z compounds are amidosilane- or
35 amidoalkanediyl- compounds of formula V wherein:
-Z*-Y- is -(ER"'2)m-N(R )-, and R' each occurrence is independently selected from
hydrogen, silyl, hydrocarbyl and combinations thereof, said R' having up to 10 carbon or silicon
atoms, or two such R' groups on the substituted cyclopentadienyl group (when R' is not
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hydrogen) together form a diva lent derivative thereof connected to adjacent positions of the
cy~lopehlddienyl ring;
R" is C1-10 hydrocarbyl;
R"' is independently each occurrence hydrogen or Cl 10 hydrocarbyl;
E is independently each occurrence silicon or carbon; and
mis1 or2.
Examples of the metal complexes according to the present invention include
compounds wherein R" is methyl, ethyl, propyl, butyl, pentyl, hexyl (including all isomers of the
foregoing where applicable), cyclododecyl, norbornyl, benzyl, or phenyl; (ER"'2)m is
10 dimethylsilane, or ethanediyl; and the cyclic delocalized n-bonded group is cyclopentadienyl,
tetramethylcyclopentadienyl, indenyl, tetrahydroindenyl, fluorenyl, tetrahydrofluorenyl or
octahydrofluorenyl.
Suitable bis-cyclopentadienyl or substituted cyclopentadienyl trdn~ on metal
compounds include those containing a bridging group linking the cyclopentadienyl groups and
15 those without such bridging groups.
Suitable unbridged bis-cyclopentadienyl or bis(substituted cyclopentadienyl)
transition metal derivatives are represented by the general formula Cp2MXn~ wherein Cp is a
n-bound cyclopentadienyl group or a n-bound substituted cyclopentadienyl group, and M and
X are as defined with respect to formula ll, and n' is 1 or 2 and is two less than the formal
20 oxidation state of M. Preferably n' is 2. Exemplary of the unbridged biscyclopentadienyl
l-dn~ilion metal derivatives are: biscyclopentadienyl zirconium dimethyl, biscyclopentadienyl
zirconium dibenzyl, bis(methylcyclopentadienyl) zirconium dimethyl, bis(n-butyl
cyclopentadienyl) zirconium dimethyl, bis(t-butylcyclopentadienyl) zirconium dimethyl,
bis(pentamethylcyclopentadienyl) zirconium dimethyl, bis(indenyl) zirconium dibenzyl,
25 bis(fluorenyl) zirconium dimethyl, bis(pentamethylcyclopentadienyl) zirconium bis[2-(N,N-
dimethylamino)benzyl], and corresponding titanium and hafnium derivatives.
P, e fer, ed bridging groups are those correspond ing to the form ula (ER"2)X
wherein E is silicon or carbon, Rn independently each occurrence is hydrogen or a group
selected from silyl, hydrocarbyi and combinations thereof, said R having up to 30 carbon or
30 silicon atoms, and x is 1 to 8. Preferably R" independently each occurrence is methyl, benzyl,
tert-butyl, or phenyl.
Exemplary bridged ligands containing two n-bonded groups are: (dimethylsilyl-
bis-cyclopentadienyl), (dimethylsilyl-bis-methylcyclopentadienyl), (dimethylsilyl-bis-
ethylcyclopentadienyl, (dimethylsilyl-bis-t-butylcyclopentadienyl), (dimethylsilyl-bis-
35 tetramethylcyclopentadienyl), (dimethylsilyl-bis-indenyl), (dimethylsilyl-bis-tetrahydroindenyl),
(dimethylsilyl-bis-fluorenyl), (dimethylsilyl-bis-tetrahydrofluorenyl), (dimethylsilyl-bis-2-
methyl-4-phenylindenyl), (dimethylsilyl-bis-2-methylindenyl), (dimethylsilyl-cyclopentadienyl-
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fluorenyl), (1,1,2,2-tetramethyl-1,2-disilyl-bis-cyclopentadienyl), (1,2-
bis(cyclopentadienyl)ethane, and (isopropylidene-cyclopentadienyl-fluorenyl).
Examples of the foregoing bridged biscyclopentadienyl or bis(substituted
- cy.lopenlddienyl) complexes are compounds corresponding to the formula Vl:
(R~2E< ~
~ /M-Xn
15 R~R' VI
wherein:
M, X, E, R', m, and n are as defined for the complexes of formula lll. Two of the
substituents X together may form a neutral n-bonded conjugated diene having from 4 to 30
non-hydrogen atoms forming a n-complex with M, whereupon M, preferably being zirconium
or hafnium, is in the +2 formal oxidation state.
The foregoing metal complexes are especially suited for the preparation of
polymershavingstereoregularmolecularstructure. Insuchcapacity,itisprer~.,edthatthe
complex possess Cs symmetry or possess a chiral, stereorigid structure. Examples of the first
type are compounds possessing different delocalized p-bonded systems, such as one
cyclopentadienyl group and one fluorenyl group. Similar systems based on Ti(lV) or Zr(lV) were
disclosed for preparation of syndiotactic olefin polymers in Ewen et al., J. Am. Chem. Soc.,
Vol.110, pp.6255-6256 (1980). Examples of chiral structures include bis-indenyl complexes.
Similar systems based on Ti(lV) or Zr(lV) were disclosed for preparation of isotactic olefin
polymers in Wild et al., J. Orqanomet. Chem., Vol. 232, pp. 233-47, (1982).
Exemplary complexes of formula lV are: (dimethylsilyl-bis-cyclopentadienyl)
zirconium dimethyl, (dimethylsilyl-bis-tetramethylcyclopentadienyl) zirconium dimethyl,
(dimethylsilyl-bis-t-butylcyclopentadienyl) zirconium diphenyl, (dimethylsilyl-bis-
tetramethylcyclopentadienyl) zirconium dibenzyl, (dimethylsilyl-bis-indenyl) zirconium bis(2-
dimethylaminobenzyl), (isopropylidene-cyclopentadienyl-fluorenyl) zirconium dimethyl,
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WO 96/16092 PCT/US95/14192
[Z,2'-biphenyldiylbis(3,4-dimethyl-1-cyclopentadienyl)] titanium dibenzyl, [6,6-dimethyl-
2,2'biphenyl-bis(3,4dimethyl-1-cyclopentadienyl)] zirconium dimethyl, and corresponding
titanium and hafnium complexes.
Suitable tricyclopentadienyl or substituted cyclopentadienyl l. ansilion metal
5 compounds include those containing a bridging group linking two cyclopentadienyl groups
and those without such bridging groups.
Suitable unbridged tricyclopenlddienyl transition metal derivatives are
represenled by general formula Cp3MXn - wherein Cp, M and X are as previously defined and
n" is three less than the formal oxidation state of M and is 0 or 1, prere- dbly 1. Preferred ligand
10 groups X are hydrocarbyl, hydrocarbyloxy, hydride, halo, silyl, germyl, amido, and siloxy.
P~ ererdbly, the transition metal compound is a bridged monocyclopentadienyl
Group 4 transition metal compound or a bridged biscyclopentadienyl Group 4 transition metal
compound, more preferably a bridged monocyclopentadienyl transition metal compound,
especially such a compound wherein the metal is titanium.
Other compounds which are useful in the preparation of catalyst compositions
according to this invention, especially compounds containing other Group 4 metals, will, of
course, be apparent to those skilled in the art.
Generally, the aluminum atom (from the alumoxane component) to transition
metal atom mole ratio in the supported catalyst is from 1 to 5000, preferably from 25 to 1000
20 and most preferably from 50 to 500. At too low ratios, the supported catalyst will not be very
active, whereas at too high ratios, the catalyst becomes less economic due to the relatively high
cost associated with the use of large quantities of alumoxane.
The quantity of transition metal compound in the supported catalyst of the
present invention is not critical, but typically ranges from 0.1 to 1000 micromoles of transition
25 metal compound per gram of support material. Preferably, the supported catalyst contains
from 1 to 250 micromoles of transition metal compound per gram of support material. It has
been found that increased aluminum loadings on the support result in catalysts having higher
efficiencies, when expressed on a transition metal basis, compared to catalysts having lower
aluminum loadings but about the same aluminum/t.dnsilion metal ratio. These higher
30 aluminum loaded support components also provide supported catalysts having higher
efficiencies, when ex~,re,~ed based on aluminum or support material.
The supported catalyst of the present invention can be used as such or in
prepolymerized form obtained by subjecting an olefin, in the presence of the supported
catalyst, to polymerization conditions.
The supported catalyst component of the invention is obtainable by heating a
support material containing alumoxane under an inert atmosphere for a period and at a
temperature sufficient to fix al umoxane to the support material.
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The support material containing alumoxane can be obtained by combining in a
diluent an alumoxane with a support material containing from 0 to not more than 20 weight
percent of water, preferably from 0 to not more than 6 weight percent of water, based on the
- total weight of support material and water. Support materials containing substantially no
5 water give good results with respect to catalytic properties of the SU,upOI led catalyst. In
addition, it has been found that support materials containing relatively small amounts of water
can be used without problem in the present process. The water containing support materials,
when combined under identical conditions with the same amount of alumoxane, gives, in the
present process, a supported catalyst component having a slightly higher aluminum content
10 than the sub~ldntially water-free support material. It is believed that the water reacts with the
residual amounts of aluminum alkyl present in the alumoxane to convert the aluminum alkyl to
extra alumoxane. An additional advantage is that, in this way, less aluminum alkyl will be lost
to waste or recycle streams. The alumoxane desirably is used in a dissolved form.
Alternatively, the support material containing alumoxane may be obtained by
combining in a diluent a support material containing from 5 to 30 weight percent water,
pl ererdbly from 6 to 20 weight percent water, based on the total weight of support material
and water, with a compound of the formula R"n*AlX"3 n* wherein R" independently each
occurrence is a hydrocarbyl radical, X" is halogen or hydrocarbyloxy, and n* is an integer from 1
to 3. Preferably, n* is 3. When the alumoxane is prepared in situ by reacting the compound of
20 theformulaR"n*AlXN3n*withwater,themoleratioofR"n*AIX"3n*towateristypically10:1
to 1 :1, preferably from 5: 1 to 1 :1.
The support material is added to the alumoxane or compound of the formula
R"n*AIXN3 n*, preferably dissolved in a solvent, most prererdbly a hyd~ ~,cdrLon solvent, or the
solution of alumoxane or compound of the formula R"n*AlX"3 n* is added to the support
25 material. The support material can be used as such in dry form or slurried in a hydrocarbon
diluent. Both aliphatic and aromatic hydrocarbons can be used. Suitable aliphatic
hydrocarbons include, for example, pentane, isopentane, hexane, heptane, octane, iso-octane,
nonane, isononane, decane, cyclohexane, methylcyclohexane and combinations of two or
more of such diluents. Suitable examples of aromatic diluents are benzene, toluene, xylene,
30 and other alkyl or halogen substituted aromatic compounds. Most preferably, the diluent is an
aromatic hydrocarbon, especially toluene. Suitable concentrations of solid support in the
hydrocarbon medium range from 0.1 to 15, preferably from 0.5 to 10, more preferably from 1
to 7 weight percent. The contact time and temperature are not critical. Preferably, the
temperature is from 0C to 60C, more preferably from 1 0C to 40C. The contact time is from
35 15 minutes to 40 hours, preferably from 1 hour to 20 hours.
Before subjecting the support material containing alumoxane to the heating
step, the diluent or solvent is removed to obtain a free-flowing powder. This is preferably done
by applying a technique which only removes the liquid and leaves the aluminum compounds
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on the solid, such as by applying heat, reduced pressure, evaporation, or combinations of such
techniques.
The heating step A followed by the optional washing step B is conducted in such a
way that a very large proportion (more than 90 percent by weight) of the alumoxane which
5 remains on the supported catalyst component is fixed. In the heating step, the alumoxane is
fixed to the support material, whereas in the optional washing step, the alumoxane which is
not fixed is removed to a substantial degree to provide the supported catalyst component of
the present invention. The upper lempe~ d lure for the heat treatment is preferably below the
temperature at which the support material begins to agglomerate and form lumps which are
10 difficult to redisperse, and below the alumoxane decomposition temperature. When the
metallocene compound is added beforethe heattreatment, aswill be explained herein, the
heating temperature should be below the decomposition temperature of the metallocene
compound. The support material containing alumoxane in free-flowing or powder form, is
preferably subjected to a heat treatment at a temperature from at least 75C, pref~rdbly at
15 least 85C, more preferably at least 1 00C, up to 250C, more preferably up to 200C for a period
from 15 minutes to 72 hours, preferably up to 24 hours. More prererdbly, the heat treatment is
carried out at a temperature from 1 60C to 200C for a period from 30 minutes to 4 hours.
Good results have been obtained while heating for 8 hours at 1 00C as well as while heating for
2 hours at 1 75C. By means of preliminary experiments, a person skilled in the art will be able
20 to define the heat treatment conditions that will provide the desired result. It is noted that the
longer the heat treatment takes, the higher the amount of al umoxane fixed to the support
material will be. The heat treatment is carried out at reduced pressure or under an inert
atmosphere, such as nitrogen gas, but pl eferdbly at reduced pressure. Depending on the
conditions in the heating step, the alumoxane may be fixed to the support material to such a
25 high degree that a wash step may be omitted.
In the optional wash step B, the number of washes and the solvent used are such
that amounts of non-fixed alumoxane are removed sufficient to give the supported catalyst
component of the invention. The washing conditions should be such that non-fixedalumoxane is soluble in the wash solvent. The support material containing alumoxane, already
30 subjected to a heat treatment, is preferably subjected to one to five wash steps using an
aromatic hydrocarbon solvent at a temperature from 0C to 1 1 ODC. More preferably, the
temperature is from 20C to 1 00C. Preferred examples of aromatic solvents include toluene,
benzene and xylenes. More preferdbly, the aromatic hydrocarbon solvent is toluene. At the
end of the wash treatment, the solvent is removed by a technique that also removes the
35 alumoxane dissolved in the solvent, such as by filtration or decdnld lion. Preferably, the wash
solvent is removed to provide a free-flowing powder of the supported catalyst component.
The wash step advantageously can be carried out under conditions of refluxing
the wash solvent. The wash step under refluxing conditions allows control of the particle size
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distribution properties, preferably to give a distribution similar to that of the starting support
material, and has also been found to give a supported catalyst having increased polymerization
activity. Typically, the supported catalyst component, after the heating step, is slurried in an
aromatic hydrocarbon, and the slurry is refluxed or heated at the boiling point of the aromatic
5 hydrocarbon. The slurry is kept at these refluxing conditions for 5 minutes up to 72 hours. Any
agglomerated particles that may have been formed during the heating step will bedeagglomerated or dispersed during the wash step at reflux condition. The longer the
refluxing conditions are maintained, the better dispersion is obtained. The concenl.dlion of
supported catalyst component in the aromatic hyd~ Gcdrbon is not critical, but is typically in the
10 range of 1 to 500 g per liter hydrocarbon, preferdbly from 10 to 250 g per liter. P~ ert r, ed
examples of aromatic hydrocarbons include toluene, benzene and xylenes. More preferably,
the aromatic hydrocarbon solvent is toluene. During the reflux step, agitation can be applied.
The supported catalyst component of the present invention, after the wash or
reflux stps described above, is preferably subjected to a dispersion treatment before combining
15 the supported catalyst component with the transition metal compound. This has been found
to increase the catalytic activity of the final supported catalyst. In general, a hydrGcd, Lon is
used as a dispersing medium, such as aliphatic, cycloaliphatic or aromatic hydrocarbons.
Suitable examples are aliphatic hydr~cd-l ons of 6 to 20 carbon atoms, preferably of 6 to
10 carbon atoms or mixtures thereof. The temperature is not critical but is conveniently in the
20 range from 0C to 50C. The duration is generally at least 5 minutes to up to 72 hours. The
upper limit is not critical but determined by practical considerations.
The transition metal compound is preferably added after the heating step, and
more preferably after both the heating step and the optional washing and dispersion steps. If
the ll dnsi lion metal compound is added before either of these steps, care shou Id be taken no
25 to submit the transition metal to too high temperatures which may cause decomposition or
inactivation thereof. Advantageously, the l~dnsilion metal compound is added after the
washing step in order to avoid that the transition metal is washed off the support material
togetherwith alumoxane.
The transition metal is contacted with the support material containing
30 alumoxane, and preferably with the supported catalyst component of the present invention, in
a diluent, preferably under such conditions that the transition metal compound is soluble.
Suitable di!uents include aliphatic and aromatic hydrocarbons, preferably an aliphatic
hydrocarbon such as, for example, hexane. The metallocene is preferably added to a slurry of
the support material, advantageously dissolved in the same diluent in which the support
35 material is slurried. Generally, the support material containing alumoxane is slurried in the
diluent at concentrations from 1 to 20, preferably from 2 to 10 weight percent. The contact
time and temperature are not critical. Preferably, the temperature is from 1 0C to 60C, more
preferdblyfrom20Cto45C. Thecontacttimeisfrom5minutesto100hours,preferablyfrom
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WO 96/16092 ~ PCT/US95/14192
0.5 hour to 3 hours. Typically, the diluent is removed after adding the metallocene. This can be
done by any suitable technique, such as applying heat and/or reduced pressure, evaporation,
filtration or decanldLion~ or any combination thereof. If heat is applied, the temperature
should not exceed the decomposition temperature of the metallocene.
It can be advantageous to subject an olefin in the presence of the supported
catalyst to polymerization conditions to provide a prepolymerized supporled catalyst.
In a highly prerer, ed embodiment, the process for preparing a supported catalyst
comprises:
heating at a temperature from 75C to 250C under an inert atmosphere,
10 preferably under reduced pressure, a silica support material containing methylalumoxane;
optionally followed by subjecting the product of the heating step to one or morewash steps using toluene;
thereby selecting the conditions in the heating step and washing step so as to
form a supported catalyst component wherein not more than 9 percent aluminum present in
15 the supported catalyst component is extractable in a one-hour extraction with toluene of 90C
using 1 g of supported catalyst component per 10 mL toluene; and
adding, after the heating step and optional washing step, a transition metal
compound selected from a bridged monocyclopentadienyl or monotsubstituted
cyclopentadienyl) Group 4 l- an~ on metal compounds or bridged biscyclopentadienyl or
20 bis(substituted cyclopentadienyl) Group 4 transition metal compounds, with the proviso that
once the transition metal compound has been added, the product thus obtained is not
subjected to temperatures equal to or higher than its decomposition temperature.Preferably, the supported catalyst so prepared contains 20 to 40 weight percent
of aluminum, based on the total weight of the support material and alumoxane.
25 Advantageously, the aluminum atom to transition metal atom mole ratio in the supported
catalyst thus formed is from 25 to 1000. Preferably, the supported catalyst so formed contains
from 0.1 to 1000 micromoles of transition metal compound per gram of support material.
The supported catalyst thus obtained may be employed as such, without isolation
or purification, but is preferably first recovered in the form of free-flowing particles. The
30 isolated catalyst can be stored under inert atmosphere for an extended period of time, for
example for one to several months. Prior to its use, the supported catalyst can be easily
reslurried in a diluent, preferably a hydrocarbon. The present supported catalyst does not
require additional activators or cocatalysts.
In a further aspect, the present invention provides an addition polymerization
35 process wherein one or more addition polymerizable monomers are contacted with the
supported catalyst according to the invention, under addition polymerization conditions.
Suitable addition polymerizable monomers include ethylenically unsaturated
monomers, acetylenic compounds, conjugated or non-conjugated dienes, polyenes, and
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carbon monoxide. P~ere"ed monomers include olefins, for example, alpha-olefins having from
2 to 20, prererdbly from 2 to 12, more prerel ably from 2 to 8 carbon atoms and combinations of
two or more of such alpha-olefins. Particularly suitable alpha-olefins include, for example,
ethylene, propylene, 1-butene,1-pentene, 4-methylpentene-1,1-hexene, 1-heptene, 1-octene,
1-nonene,1-decene,1-undecene,1-dodecene,1-tridecene, 1-tetradecene,1-pentadecene, or
- combinations thereof. P~ ~ r~, dbly, the alpha-olefins are ethylene, propene,1-butene,
4-methyl-pentene-1,1-hexene,1-octene, and combinations of ethylene and/or propene with
one or more of such other alpha-olefins. Other prer~r,~d monomers include styrene, halo- or
alkyl substituted styrenes, vinyl chloride, acrylonitrile, methyl acrylate, methyl methacrylate,
10 tetrafluoroethylene, methacrylonitrile, vinylidene chloride, vinylcyclobutene,1,4-hexadiene,
and 1,7-octadiene. Suitable addition polymerizable monomers also include any mixtures of the
above-mentioned monomers.
The supported catalyst can be formed in situ in the polymerization mixture by
introducing into said mixture both a supported catalyst component of the present invention as
15 well as a suitable metallocene component. The supported catalyst component and the
supported catalyst of the present invention can be advantageously employed in a high
pressure, solution, slurry or gas phase polymerization process. A high pressure process is usually
carried out at temperatures from 100C to 400C and at pressures above 500 bar. A slurry
process typically uses an inert hydrocarbon diluent and temperatures of from 0C up to a
20 temperature j ust below the temperature at which the resulting polymer becomes substantially
soluble in the inert polymerization medium. P~ ~ferled temperatures are from 20C to 115C,
preferdbly from 60C to 105C. The solution process is carried out at temperatures from the
temperature at which the resulting polymer is soluble in an inert solvent up to 275C.
6enerally, solubility of the polymer depends on its density. For ethylene copolymers having
25 densities of 0.86 g/cm3, solution polymerization may be achieved at temperatures as low as
60C. P~ ererdbly, solution polymerization temperatures range from 75C to 260C, more
preferdbly from 80C to 170C. As inert soivents, typically hydrocarbons and -prererdbly
aliphatic hydrocarbons are used. The solution and slurry processes are usually carried out at
pressures between 1 to 100 bar. Typical operating conditions for gas phase polymerizations are
30 from 20C to 100C, more preferably from 40C to 80C. In gas phase processes, the pressure is
typicallyfrom subatmosphericto 100 bar. Typical gas phase polymerization processes are
disclosed in U.S. Patents 4,588,790, 4,543,399, 5,352,749, 5,405,922, and U.S. Applicatioin Serial
No. 122,582,filed September 17,1993 (corresponding toWO 9507942).
Preferably, for use in gas phase polymerization processes, the support has a
35 median particle diameter from 20 to 200 i~m, more preferably from 30 ~um to 150 ilm, and most
preferablyfrom35~umto100~um. P~efeldblyforuseinslurrypolymerizationprocesses,thesupport has a median particle diameterfrom 1 to 200 iJm, more preferably from 5 i m to 100
m, and most preferably from 20 i m to 80 i m. Preferably, for use in solution or high pressure
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CA 0220~376 1997-0~-14
WO 96/16092 PCT/US95/14192
polymerization processes, the support has a median particle diameter from 1 to 40,um, more
preferably from 2 ,um to 30 ,um, and most preferably from 3 ~Im to 20 ,um.
The supported catalysts of the present invention, when used in a slurry process or
gas phase process, not only are able to produce ethylene copolymers of densities typical for
high density polyethylene, in the range of 0.970 to 0.940 g/cm3, but su"uri~ingly~ also enable
the production of copolymers having substantially lower densities. Copolymers of densities
lower than 0.940 g/cm3 and especially lower than 0.930 g/cm3 down to 0.880 g/cm3 or lower
can be made while retaining good bulk density properties and while preventing orsubstantially eliminating reactor fouling. The present invention is capable of producing
10 ethylene polymers and copolymers having weight average molecular weights of up to
1,000,000 and even higher.
In the polymerization process of the present invention, impurity scavengers may
be used which serve to protect the supported catalyst from catalyst poisons such as water,
oxygen, and polar compounds. These scavengers can generally be used in amounts depending
15 on the amounts of impurities and are typically added to the feed of monomers and diluent or
to the reactor. Typical scavengers include trialkyl aluminum or boron compounds and
alumoxanes.
In the present polymerization process, also, molecular weight control agents canbe used, such as hydrogen or other chain transfer agents.
Having described the invention, the following examples are provided as further
illustration thereof and are not to be construed as limiting. Unless stated to the contrary, all
parts and percentages are ex,~,ressed on a weight basis.
Examples
In the examples, the following support materials were used: granular silica
available from Grace GmbH under the designation SD 3216.30; a spherical agglomerated silica
available as SYLOPOL 2212 from Grace Davison (division of W.R. Grace & Co.) having a surface
area of 250 m2/g and a pore volume of 1.4 cm3/g. Unless indicated otherwise, the silicas used
have been heated at 250C for 3 hours under vacuum to give a final water content of
substantially 0 as determined by di rrerenlial scanning calorimetry. Where a silica is used
30 containing water, it was used as supplied, without heat pretreatment.
Alumoxane was used as a 10 weight percent solution of methylalumoxane (MAO)
in toluene available from Witco GmbH. Metal locene was used as a 0.0714M solution of {(tert-
butylamido) (tetramethyl-rlS-cyclopentadienyl) (dimethyl) silane}titanium dimethyl
(hereinafter MCpTi) in ISOPARTU E (trademark of Exxon Chemical Company).
The bulk density of the polymers produced was determined according to ASTM
1895. The aluminum content on the support material was determined by treatment with
sulfuric acid, followed by EDTA addition and back titration with zinc chloride.
=
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WO 96/16092 PCTIUS95/14192
All experiments were pe, ro""ed under a nitrogen atmosphere, unless indicated
otherwise.
Example 1
- A 1000 mL flask was charged with 11.1 g of silica SD 3216.30. 300 9 of MAO
5 solution was added and the mixture stirred for 16 hours. Then the solvent was removed under
reduced pressure at 20C to yield 38 9 of a free-flowing powder having an aluminum content of
31.6 percent. The sample was split into four equal portions of 9 9 and each was heated at a
dirfere"l temperature for Z hours under reduced pressure. After this treatment, the aluminum
content of each sample was measured and then each was slurried in toluene (100 mL) and the
10 mixture stirred for 1 hour, filtered, and then the supports washed with two 50 mL portions of
fresh toluene and dried under vacuum at 1 20C for 1 hour. The results of the aluminum
analyses are summarized below.
Table I - Heat Treatment / Room Temperature Toluene Wash
T[C [AllAfterHeating [AllAfterWashing
] (wt% ) (wt% )
125 30.7 20.3
150 30.0 25.7
175 30.8 30.3
200 31.1 31.4
The above procedure was repeated but with 12.1 9 silica, and 327 9 MAO solution
to yield 42 9 of free-flowing powder having an aluminum content of 31.3 percent. This sample
was split into four equal portions and each was heated as described above, and then subjected
to the same wash procedure exceptthat toluene of 90C was used. The results are summarized
in Table ll.
Table ll - Heat Treatment / 90C Toluene Wash
T [C ] [Al] After Heating (wt%) (wt%)
125 31.0 16.4
150 30.7 23.8
175 30.7 29.3
200 31.0 29.1
These examples show that, for heat treatments of the duration, an increase in the
heat treatment temperature resu Its in more alumoxane becom ing fixed to the si lica. The 90C
toluene wash results in an increased percentage of non-fixed aluminum being removed,
35 compared to the room temperature tol uene wash for wash treatments of the same duration.
=
CA 0220~376 l997-0~-l4
WO 96/16092 PCT/US95/14192
Example 2
A 250 mL flask was charged with 6.2 g of silica SD 3216.30. 168 g of MAO solution
was added and the mixture stirred for 16 hours. Afterthis time, the toluene was removed
under reduced pressure at 20C, and then the solids were dried under vacuum for 16 hours at
5 20C to yield a free-flowing powder. The weight of the solid was 22.1 g and the aluminum
content was 26.8 percent.
Example 3
The procedure of Example 2 was repeated using 3 g silica and 56.6 g of MAO
solution to give 7.6 9 of a free-flowing powder having an aluminum content of 26.1 percent.
10 5.2 9 of this support was slurried in toluene (50 mL) at 20C and the mixture stirred for 1 hour.
The mixture was filtered and the support washed with two 20 mL portions of fresh toluene and
then dried under vacuum at 20C for 1 hour. The weight was 3.0 g and the aluminum content
was 18.2 percent.
Example 4
The procedure of Example 2 was repeated using 3 9 of silica and 75.6 9 of MAO
solution to give a free-flowing powder. This powder was then heated at 1 00C for two hours
under vacuum. The weight was 8.4 9 and the aluminum content was 29.0 percent. 4.4 9 of this
support was slurried in toluene (50 mL) at 20C and the mixture stirred for 1 hour. The mixture
was filtered and the support washed with two 20 mL portions of fresh toluene and then dried
under vacuum at 20C for 1 hour. The weight was 2.2 9 and the aluminum content was
17.3 percent.
Example 5
The procedure of Example 2 was repeated using 3 9 silica and 56.6 9 MAO
solution to give a free-flowing powder. The powder was heated for two hours at 1 50C under
vacuum. The weight obtained was 7.2 9 and the aluminum content 26.6 percent.
Example 6
The procedure of Example 2 was repeated using a 1000 mLflask, 12.1 9 of silica,
and 327 g of MAO solution to yield a free-flowing powder. 9.5 9 of this powder was then
heated at 175C fortwo hours under vacuum. The aluminum content was measured as
30-7 percent. 2.7 g of this support was slurried in hexane (40 mL) at 20C and the mixture
stirred for 4 hours. The m ixture was filtered and the support washed with two 30 mL portions
of fresh hexane and then dried under vacuum at 20C for 1 hour. The weight was 2.4 g and the
aluminum content was 30.4 percent.
Example 7
The procedure of Example 2 was followed. This powder was then heated at 1 50C
for two hours under vacuum. The weight was 7.25 9 and the aluminum content was 26.6
percent. 3 g of the support obtained was slurried in toluene (40 mL) at 20C and the mixture
stirred for 1 hour. The mixture was filtered and the support washed with two 10 mL portions of
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WO 96/16092 PCT/US95/14192
fresh toluene and then dried under vacuum at 20C for 1 hour. The weight was 2.4 9 and the
aluminum content was 24.1 percent.
Example 8
The procedure of Example 2 was repeated using 3 g of silica and 75.5 9 of MAO
5 solution to yield a free-flowing powder. This powder was heated at 150C for two hours under
vacuum. The weight was 8.4 g and the aluminum content was 29.8 percent. 5 9 of this support
was slurried in toiuene (40 mL) at 20C and the mixture stirred for 1 hour. The mixture was
filtered and the support washed with two 20 mL portions of fresh toluene and then dried
under vacuum at 20C for 1 hour. The weight was 4.5 9 and the aluminum content was
10 28-9 percent.
Example 9
The procedure of Example 2 was repeated using a 1000 m L flask, 9.1 g silica and246 g MAO solution to give a free-flowing powder. This powder was then heated at 150C for
two hours under vacuum. The weight was 29.0 g and the aluminum content was 29.6 percent.
15 This support was slurried in toluene (300 mL) at 20C and the mixture stirred for 1 hour. The
mixture was filtered and the support washed with two 100 mL portions of fresh toluene and
then dried under vacuum at 20C for 1 hour. The weight was 24.3 g and the aluminum con lent
was 28.5 percent.
Example 10
The procedure of Example 2 was repeated using 5 g silica and 101 g MAO solution
to yield a free-flowing powder. The powder was heated at 175C for two hours under vacuum.
The aluminum content of this materia I was 28.8 percent. The powder (12.8 9) was reslurried in
toluene (130 mL) and the mixture heated to 90C and stirred for 1 hour. The mixture was
filtered and the resulting solid washed with two 50 mL portions of fresh toluene at 90C. The
support was then dried under vacuum at 120C for 1 hour. 10.4 g of support was obtained
having an aluminum content of 26.3 percent.
Example 11
The procedure of Example 2 was repeated using 10 9 silica and 76 9 MAO solution
to give a free-flowing powder. This powder was heated at 175C for two hours under vacuum.
The aluminum content of this material was 17.2 percent. The powder (15.6 9) was reslurried in
toluene (150 mL) and the mixture heated to 90C and stirred for 1 hour. The mixture was
filtered and the resulting solid washed with two 50 mL portions of fresh toluene at 90C. The
support was then dried under vacuum at 120C for 1 hour. 13.0 9 of support was obtained
having an aluminum content of 16.3 percent.
35 Example 12
The procedure of Example 2 was repeated using 5 9 silica SD 3216.30 having a
water content of 2.8 percent, and 101 9 of MAO solution to give a free-flowing powder. This
powder was heated at 175C for two hours under vacuum. The aluminum content of this
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WO 96/16092 PCT/US9!;/14192
material was 29.4 percent. The powder (13 g) was reslurried in toluene (130 mL) and the
mixture heated to 90C and stirred for 1 hour. The mixture was filtered and the resulting solid
washed with two 50 mL portions of fresh toluene at 90C. The support was then dried under
vacuum at 120C for 1 hour. 11.5 9 of support was obtained having an aluminum content of
5 29.0 percent.
Example 13
The procedure of Example 2 was repeated using a 1000 m L flask, 9 g of SYLOPOL
2212 and 243 g MAO solution to give a free-flowing powder. This powder was heated at 150C
for two hours under vacuum. The weight was 29.3 9 and the aluminum content was 29.8
10 percent. This support was slurried in toluene (300 mL) at 20C and the mixture stirred for 1
hour. ThemixturewasfilteredandthesupportwashedwithtwolOOmLportionsoffresh
toluene and then dried under vacuum at 120C for 1 hour. The weight was 25.9 g and the
aluminum content was 29.3 percent.
Example 14
Theprocedureof Example2wasrepeated usinga 1000mLflask,9.1 gsilicaand
246 9 MAO solution to give a free-flowing powder. This powder was heated at 175C for two
hours under vacuum. The weight was 30.8 9 and the aluminum content was 30.0 percent. This
support was slurried in toluene (300 mL) at 20C and the m ixture stirred for 1 hour. The mixture
was filtered and the support washed with two 100 mL portions of fresh toluene and then dried
20 under vacuum at 120C for 1 hour. The weight was 27.1 g and the aluminum content was
29.0 percent.
Example 15
The procedure of Example 2 was repeated using 5.1 9 silica and 101 g MAO
solution to give a free-flowing powder. 6.8 g of this powder was heated at 100C for two hours
25 under vacuum. The support was then slurried in toluene (100 mL) at 90C and the mixture
stirred for 1 hour. The mixture was filtered and the support washed with two 50 mL portions of
fresh toluene (90C) and then dried under vacuum at 100C for 1 hour. The weight was 3.4 g
and the aluminum content was 16.6 percent.
Example 16
The procedure of Example 2 was repeated using 5.1 g silica and 101 g MAO
solution to give a free-flowing powder. 6.8 g of this powder was slurried in toluene (100 mL) at
90C and the mixture stirred for 1 hour. The mixture was filtered and the support washed with
two 50 mL portions of fresh toluene (90C) and then dried under vacuum at 100C for 1 hour.
Theweightwas3.0gandthealuminumcontentwas13.4percent.
35 Example 17
The procedure of Example 2 was repeated using 5 g of silica SD 3216.30
containing Z.8 percent of water, and 101 g MAO solution to give a free-flowing powder. 6 g of
this powder was slurried in toluene (100 mL) at 90C and the mixture stirred for 1 hour. The
-26-
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WO 96/16092 PCT/US95/14192
mixture was filtered and the support washed with two 50 mL portions of fresh toluene (90C)
and then dried under vacuum at 20C for 1 hour. The weight was 2.9 9 and the aluminum
content was 16.4 percent.
Example 18
The procedure of Example 2 was repeated using 5 9 of silica SD 3216.30
- containing 2.8 percent of water, and 101 g MAO solution to give a free-flowing powder. This
powder was heated at 1 00C for 2 hours. 6 9 of this powder was slurried in toluene (100 mL) at
90C and the mixture stirred for 1 hour. The mixture was filtered and the support washed with
two 50 mL portions of fresh toluene (~0C) and then dried under vacuum at 20C for 1 hour.
10 The weight was 3.8 9 and the aluminum content was 22.2 percent.
Example 19
Preparation of suPported catalYsts
Supported catalysts were prepared from the supported catalyst components
prepared in Examples 2 to 18 according to the following procedure.
Typically, 1 g of support component was slurried in 20 mL hexane and the mixturestirred for 30 minutes. An aliquot of MCpTi solution (0.0714M) was added sufficient to give a
transition metal loading as shown in Table lll. This mixture was stirred for 30 minutes and then
t. dn,~r, ed to a polymerization reactor.
Polvmerization
A 10 L autoclave reactor was charged with 6 L anhydrous hexane, co-monomer if
required, hydrogen gas if required, and the conle,.lswere heated to 80C, unless otherwise
stated. Ethylene was added to raise the pressure to the desired level. The amount of the
supported catalyst indicated in Table lll was added through a pressurized addition cylinder.
Ethylene was supplied to the reactor continuously on demand. After the desired
25 poiymerization time, the ethylene I ine was blocked and the reactor conter.l, were dumped into
a sample container. The hexane was decanted from the polymer and the polymer dried
overnight and then weighed to determine the yield.
In run 22, the temperature was 70C, and 100 mL of 1 -octene comonomer was
added to the reactor to give an ethylene/1-octene copolymer of density 0.9266 g/cm3. In run
30 23, the temperature was 50C, and 200 mL of 1 -octene comonomer was added to the reactor to
give an ethylene/1-octene copolymer of density 0.9230 g/cm3.
The specific polymerization conditions and results are summarized in Table lll.
The data in this table show that high bulk density polymers can be prepared from supported
catalyst components prepared with various combinations of heat and/or wash treatments. The
35 highest efficiencies result from supported catalyst components and catalysts containing more
than 20 percent Al by weight. Superior efficiencies are obtained from supported catalyst
components subjected to dispersion in 90C toluene. Poor bulk densities (runs 1 to 3) result
CA 02205376 1997-05-14
W O 96/16092 PCTAUS95/14192
from supported catalyst components which have either not been heat-treated at a sufficientiy
high temperature or for a sufficiently long time, or have not been sufficiently washed.
CA 02205376 1997-05-14
WO 96/16092 PCT/US95/14192
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CA 02205376 1997-05-14
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CA 0220~376 1997-0~-14
WO 96/16092 PCT/US95114192
Example 20
The procedure of Example 2 was repeated using 6.2 9 of silica SD 3216.30, and 68g MAO solution to give 22.1 9 of free-flowing powder having an aluminum conlenl of 27.8
percent. 11 9 of this support was slurried in toluene (75 mL) and 440 micromoles of MCpTi (6.16
m L of a 0.0714M solution in hexane) was added. The m ixture was stirred 1 hour and then the
solvent was removed under reduced pressure and the residue heated at 150C for two hours.
This yielded 11 9 of a free-flowing powder having an aluminum content 28.2 percent. The
material was slurried in toluene (100 mL) and the mixture stirred for 1 hour, filtered, and the
solids washed with two 50 mL portions of fresh toluene and then dried under vacuum at 100C
for 1 hour. The weight was 9 9, the aluminum content was 24.8 percent, and the Ti content was
40 micromoles/g.
Example 21
The procedure of Example 6 was repeated using 12.1 9 of silica SD 3216.30, and
327 9 MAO solution to give a free-flowing powder. 9.1 9 of this powder was heated at 150C
under vacuum for 2 hours to yield a material with an aluminum content of 30.7 percent. 3.5 9
of this powder was slurried in toluene (35 mL) and 140 micromoles of MCpTi (1.96 mL of a
0.0714M solution in hexane) added and the mixture stirred for 1 hour. The mixture was filtered
and the support washed with six 50 mL portions of fresh toluene (at which point the washings
were colorless) and then dried under vacuum at 20C for 1 hour. The weight was 22.0 9 and the
20 Ti content30 micromoles/g.
Example 22
The procedure of Example 2 was repeated using 3.0 9 of si lica SD 3216.30, and 82
g MAO solution to give 10.5 9 of free-flowing powder. 4.85 9 of this powder was slurried in
toluene (50 mL) and the mixture stirred for one hour. The mixture was filtered and the support
25 washed with two 20 mL portions of fresh tol uene and then heated under vacuum at 150C for
2 hours. The weight was 2.1 9 and the aluminum content was 14.9 percent. MCpTi was added
according to the procedure of Example 19.
Example 23
A 250 mL flask was charged with 3.3 9 of silica SD 3216.30. Toluene (80 mL) was
30 addedtotheslurryfollowedby130micromolesofMCpTi(1.82mLofaO.0714Msolutionin
hexane) and the mixture stirred for two hours. 101 9 of MAO solution was added and the
m ixture stirred for 16 hours. After this time, the solvent was removed under red uced pressure,
at 20C, to yield a free-flowing powder.
Following the general polymerization procedure of Example 19, using the specific35 conditions mentioned in Table IV, the results indicated in the same table were obtained.
The data in this table show that a low activity catalyst results when the
metallocene is added before a heat treatment of 150C (Example 20). A reasonable bulk
density is obtained when the metallocene is added after the heat step, but prior to wash step
-31 -
CA 0220~376 1997-0~-14
Wo 96/16092 PCT/US95114192
(Example 21). A good bulk density results when the wash step is performed prior to the
heating step (Example 22). An inactive catalyst results when the metallocene is first added to
the silica (Example 23).
-32-
CA 02205376 1997-05-14
WO 96/16092 PCTIUS95/14192
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CA 0220~376 1997-0~-14
WO 96/16092 PCT/US95/14192
Example 24
The procedure of Example 1 was repeated except that after removing the solvent
from the MAO/silica mixture under reduced pressure at 20C, portions of the resulting powder
were subjected to two hour heat tredl")en l~ and optional wash treatments as summarized in
5 Table V. After these treatments, the supported catalyst components were, on the one hand,
extracted with 90C toluene to establish the percenldge aluminum extractables, and, on the
other hand, used in polymerization reactions. All wash and extraction steps were pe, ror."ed
with 1 g support per 10 m L toluene, stirred for one hourl then filtered and washed with 2 times
5 mL toluene per gram initial support. The supported catalysts were prepared according to the
10 general procedure described in Example 19. All polymerizationswere perr~.r",ed at 15 bar
total pressure at 80C for one hour. The results are given in Table Vl. The examples show that
at extractable aluminum percentages well below 10 percent, excellent bulk densities are
obtained. = ==
The 1 75C heat treatment alone in run 1, without any wash treatment, enabled
15 polymers of good bulk density to be made.
Table V Extraction Test
Heat 20C Alin t AlAfter Extracted Bulk
RunTreatment Toluene CatalysExtraction Al Density
Temp. [C] Wash SUPPort [o/] [%] [g/cm3]
1 175 no 29.8 27.9 6.4 0.35
2 175 yes 28.3 27.9 5.0 0.34
3 165 no 30.5 27.6 10 0.12
4 165 yes 29.3 27.6 5.8 0.31
125 no 30.1 20.9 33 0.06
6 75 yes 16.6 15.9 4.2 0.34
-34-
CA 02205376 1997-05-14
WO 96116092 PCT/US95/14192
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CA 0220~376 1997-0~-14
WO 96/16092 PCT/US95/14192
Example 25
The procedure of Example 2 was repeated using 5 g silica and 101 9 MAO solution
to give a free-flowing powder. The powder was heated at 100C for eight hours under vacuum
to yield 12.5 9 of material. The support was then slurried in toluene (125 mL) at 90C and the
5 mixture stirred for one hour. The mixture was filtered and the support washed with two 50 mL
portions of fresh toluene (90C) and then dried under vacuum at 100C for one hour. The
weight was 11.1 grams and the aluminum content was measured as 26.1 percent by weight.
A~curding to the procedures of Example 19 and using the amounts in Table Vll, a
polymerization experiment was per ru, -, led at 15 bar total pressure,80C, for one hour. The
10 results are included in Table Vll.
Table Vll Polymerization Run
Tj2 [Ti~4 Yield7 E(Ti)s E(SiO2)9 E(Al)-o Bulk
[llmol/ Al/Ti3 ( mol) ( ) [gPE/g[gPE/gSiO2 [gPE/gAI/ Dens.
9] 11 9 Ti/hr] /hr] hr] (g/cm3)
242 20 365 381,002 1,662 2,797 0.33
Footnotes are the same as in Table lll
Example 26
The procedure of Example 5 from U.S. Patent 5,240,894 was essenlidlly repeated
to form a supported catalyst component as follows. 0.58 ~umoles of MCpTi (8.1 mL of a 0.0714M
solution) was added to 35 mL toluene. To this was added 75 mL of 10 weight percent MAO in
toluene and the mixture stirred for 15 minutes. Silica (5 9, SD 3216.30, pretreated at 250C for
three hours) was added and the mixture stirred 20 minutes. The mixture was heated at 65C
under vacuum for 75 minutes and the dried solid washed with 2x70 mL pentane, filtered and
dried under high vacuum to give a yellow solid (8 9) having an aluminum content of 18.1
percent by weight. A toluene extraction at 90C followed by drying gave a yellow solid with an
aluminum content of 16.2 percent by weight. The extractable aluminum percentage is
10.5 percent. Upon washing, some MCpTi was lost and also upon the hot toluene extraction, as
30 indicated by the yellow color of the supernatant. Polymerization experiments following the
general procedure of Example 19 were performed with a supported catalyst that was not
treated with hot toluene (run 1) and with one that was treated with hot toluene (run 2). The
results are given in Table Vlll.
The results show that the non-toluene-treated catalyst (having 10.5 percent
35 extractable Al) gives a poor bulk density. Subjecting the obtained supported catalyst to a hot
toluene extraction greatly improves the bulk density (run 2).
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WO 96/16092 PCT/US95/14192
Table Vlll
Run Al Time YieldBulk Dens.
" No. (%) (min) (g) (g/cm3)
1 18.1 60 175 0.10
2 1 6.2 60 50 0.30
Example 27
A 1000 mL flask was charged with 508 9 of 10 percent MAO solution in toluene
and 25 9 of silica SYLOPOL 2212 having a water content of 3.5 percent was added while
continuously stirring. The mixture was stirred for a further two hours and then the solvent was
removed under reduced pressure at 20C to yield a free-flowing powder. This powder was then
heated at 1 75C for two hours under vacuum. The powder was reslurried in toluene (700 mL)
and the mixture was heated and refluxed for one hour. The mixture was filtered and the
supportwashedwithtwo200mLportionsoffreshtolueneat100C. Thesupportwasthen
dried under vacuum at 1 20C for 1 hour. 63.9 9 of support was obtained having an aluminum
content of 26.4 percent. A sample of the support was slurried in toluene, agitated for one
hour, and then the particle size distribution was measured on a Malvern Ma~ler~i~er X
instrument. This indicated d(v, 0.5) to be approximately 12 microns. According to this
procedure further supported catalyst components were prepared having slightly dirrere"l
aluminum loadings.
A weighed amount of the support components was slurried in hexane and the
mixture stirred for 16 hours before addition of the MCpTi component (runs 1 to 3) or ~(tert-
butylamido)(tetramethyl-rlS-cyclopentadienyl) (dimethyl) silane} titanium rl4-1 ,3-pentadiene
(hereinafter MCpTi(ll) in run 4). Subsequently, MCpTi or MCpTi(ll) was added (in ISOPART" E) in
the amounts as indicated in Table IX. The supported catalysts thus prepared were subjected to
slurry polymerization as generally described in Example 19 at 80C. The other conditions and
results are mentioned in Table IX. These results show that using an extended dispersion period
before the transition metal compound is added results in increased catalytic activity (compare
with Table lll).
CA 02205376 1997-05-14
WO 96116092 PCT/US95/14192
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Z
CA 0220~376 1997-0~-14
WO 96/16092 PCT/US95/14192
Example 28
A 3 L autoclave reactor was charged with an amount of 1-octene as indicated in
Table X followed by an amount of Isopar"' E sufficient to give a total volume of 1500 mL. 300
mL of hydrogen gas was added and the reactor cunte~ were heated to the desired
5 temperature. Ethylene was then added sufficient to bring the pressure of the system to 30 bar.
A supported catalyst was added to initiate the polymerization and ethylene was supplied to the
reactor continuously on demand. After the desired polymerization time, the ethylene line was
blocked and the reactor con Len l~ were dumped into a sample container. The polymer was
dried overnight and then weighed to determine catalyst efficiencies. The results are described
10 in Table X, wherein the molecular weight distribution (MwlMn) is derived from gel permeation
chromatoyldphy~ and the melt index 12 is determined according to ASRM D-1238-65T (at 190C
and 2.16 kg load).
The following supported catalysts were used in the polymerizations. A support
containing 23.8 percent aluminum on dehydrated SD 3216.30 silica was prepared in a manner
similar to Example 10. In runs 1 to 3, 0.075 9 of support was slurried in Isopar"', and stirred for a
few minutes. An aliquot of MCpTi solution (0.0714M) was added, sufficientto give a titanium
loading of 20 ,umoles/g. This mixture was stirred for a few minutes and then l. dn~r~r, ed to the
polymerization reactor. In runs 4 to 6, 0.3 9 of support was used and the same titanium
loading.
Table X
Run 1-octene Time Yield Average Effi j 12 Density
No. [ml] [min] [gram] [ocjP [gPE/gTi] [m/in] [g/cm3] MWlMn
1 302 20 69 81 960,334 0.25 0.882 2.18
2 382 20 55 80 765,484 0.25 0.873 2.09
3 456 17 35 80 487,126 0.41 0.870 2.09
4 455 20 244 133 848,990 1.30 0.877 2.44
455 20 217 143 755,045 0.47 0.882 2.88
6 457 20 200 152 695,894 0.33 0.880 2.99
When used in a solution polymerization process, the supported catalysts show
good efficiencies and make narrow molecular weight distribution polymers.
Example 29
In the present example, continuous polymerization runs are described. These
runs were performed using a supported catalyst prepared according to a procedure similar to
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CA 0220~376 lgg7-0~-l4
WO 96116092 PCT/US95/14192
that of Example 27. The support contained 25 weight percent of aluminum. In all runs, the
loading of MCpTi was 40 ymoles/g.
Isopentane, ethylene,1-butene, hydrogen and supported catalyst were
continuously fed into a 10 L jacketed, contin uously stirred tank reactor and the sl urry product
5 formed was removed continuously. The total pressure in all polymerization runs was 15 bar.
The slurry withdrawn was fed to a flash tank to remove the diluent and the dry, free-flowing
polymer powder was collected. Table Xl summarizes the condilions and the properties of the
products made. The melt index values were measured a.cc r.Ji"g to ASTM D-1238-65T (at 190C
and a load of 21.6 kg, abbreviated as 121)- The butene content of the polymerwas determined
10 byin~ld-edspe~l~oscopy. Theresultsindicatethathighbulkdensitypolymerpowderscanbe
produced over a wide density range, with particle morphology being retained.
Table Xl
Isopen Ethyl Butene Hydro 1216 Polymer
Run tane ene Flow gen T(C) [g/;0 Density Butene B.D.
No. Flow Flow Flow .[g/cm3] Content g/cm3
[g/h] [g/h] [g/h] ll/h] mln][wt %]
2500 1600 195 0.54 601.28 0.9305 1.94 0.34
2 2500 1000 80 0.30 600.38 0.9136 5.58 0.34
3 2500 800 80 0.30 550.28 0.9190 6.34 0.38
4 2500 1150 125 0.30 550.18 0.9112 8.54 0.39
2500 850 100 0.30 550.21 0.9050 10.18 0.37
6 2500 675 100 0.30 550.45 0.9035 11.64 0.38
7 2500 550 160 0.50 351.40 0.8958 14.60 0.23
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