AU603487B2 - Method for preparing an active metallocene-alumoxane catalyst in situ during polymerization - Google Patents

Description

AU-AI-24251/ 8 8 WORLD INTELLECTUAL PROPERTY ORGANIZATION pc-i [nternational Bureau INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 4 (11) International Publication Number: 'WO 89/ 02448 C08F 10/00, 4/62 Al (43) International Publication Date: 23 March 1989 (23,03,89) (21) International Application Number: PCT/US88/03 113 (81) Designated States: AU, BR, DK, Fl, HU, JP, KR, NO, Sul (22) International Filing Date: 9 September 1988 (09.09.88) Published (31) Priority Application Number: 096,088 With internalional search report.

(32) Priority Date: 14 September 1987 (14.09.87) (33) Priority Country: us S 7 (71)Applicatt EXXON CHEMICAL PATENTS, INC, (US/US]; 1900 East Linden Avenue, Linden, NJ 0703 6-07 10 (US).

Inventor; CHANG, Main ,15910 Dunmoor Drive, Houston, TX 77059 (US).

(74) Agent: KURrZMAN, Myron, Exxon hmia Company, RIO. Box 5200, Baytown, TX 77522-5200 A. 0. L .25 MAY 1989 I AUSTRALIAN I 17 APR i989 PATENr OFFICE (54)Titlc; METHIOD FOR PREPARING AN ACTIVFE METALL.OCENEALUMOXANE CATALYST IN SITU DURING POLYMIERIZATION (57) Abstract Amethod for preparing artactive metlocn-alumoxane catalyst in f$:u 4urig polymerization, A metallocene-aluminumn alkyl catalyst complex is activated during olef in polymerizato byfelg Wet monomer to a reaction vessel, Water entrained, in the monor a 0-il p ecswt the alinum alkyl In the catalyst complex to form an aluw moxane, activating the resulting metallocene-alumoxane catalyst complex and initiating polymerization of the olein monomer, The method is applied to batch and continuous olefin polymerization in gas or solution phase, The catalyst complex may be homogeneous or supported,

I

WO 89/02448 PCT/US88/03113 METHOD FOR PREPARING AN ACTIVE METALLOCENE-ALUMOXANE CATALYST IN SITU DURING POLYMERIZATION This invention relates to a process for polymerizing olefins wherein a catalytic precursor composition is safely rendered catalytically active by exposure to water vapor contained in a monomer feed stock. The invention particularly relates to the polymerization of ethylene in the presence or absence of alpha-olefin comonomers, wherein the catalytically active composition comprises a metallocene and an alumoxane, the alumoxane component being formed in situ by exposure of an aluminum alkyl to water vapor contained in a monomer feed st6ck supplied to the polymerization reaction vessel.

Background to the Invention Olefin polymerization catalysts comprising a metallocene and an aluminum alkyl component were first proposed in about 1956. Australian patent 220436 proposed for use as a polymerization catalyst a bis- (cyclopentadienyl) titanium, zirconium, or vanadium salt as reacted with a variety of halogenated or unhalogenated aluminum alkyl compounds. Although such complexes were capable of catalyzing the polymerization of ethylene, such catalytic complexes, especially those made by reaction with an aluminum trialkyl, had an insufficient level of catalytic activity to be employed commercially for production of polyethylene or copolymers of ethylene.

In U.S. Patent 3,051,690, there is described a catalytic process for polymerizing olefins to high molecular weight polyt4,Iefins of controlled molecular weight by the addition of controlled amounts of hydrogen to the polymerization system. The catalyst by which such polymerization is carried out comprises a reaction product of a compound of a metal of Group IVB, VB, VIB, and VIII with an organometallic compound of an alkali metal, alkaline earth metal, zinc, earth metal or rare earth metal. The patent teaches that an increased use of hydrogen during the polymerization process results in a decrease in the molecular weight of the resulting polymer.

WO 89/02448 PCT/US88/03113 -2- More active forms of metallocenes and aluminum alkyl catalysts have been found, but to exercise control over the molecular weight of the resulting polymer the most expedient control has been the addition during polymerization of hydrogen or other molecular weight modifier.

It has been found that certain metallocenes such as bis-(cyclopentadienyl) titanium, or zirconium dialkyls in combination with aluminum alkyl/water cocatalyst form catalyst systems for the polymerization of-ethylene. Such catalysts are discussed in German Patent Application 2,608,863 which discloses a polymerization catalyst for ethylene consisting of bis-(cyclopentadienyl) titanium dialkyl, aluminum trialkyl and water. German Patent Application 2,608,933 discloses an ethylene polymerization catalyst consisting of a cyclopentadienyl zirconium salt, an aluminum trialkyl cocatalyst and water. European Patent Application No. 0035242 discloses a process for preparing ethylene and atactic propylene polymers in the presence of a halogen free cyclopentadienyl transition metal salt and an alumoxane. Such catalysts have sufficient activity to be commercially useful and enable the control of molecular weight by means other than hydrogen addition such as by controlling the reaction temperature or by controlling the amount of alumoxane as such or as produced by the reaction of water with an aluminum alkyl.

To realize the benefits of such catalyst systems, one must use, or produce in situ, the required alumoxane cocatalyst component. An alumoxane is produced by the reaction of an aluminum alkyl with water. The reaction of an aluminum alkyl with water is a very rapid and highly exothermic one. Because of the extreme violence of the reaction the alumoxane cocatalyst component has, heretofore, been made by one of two general methods, Alumoxanes may be prepared by adding an extremely finely divided water, such as in the form of a humid solvent, to a solution of aluminum alkyl in benzene or other aliphatic hydrocarbons. The production of an alumoxane by such i WO 89/02448 PCT/US88/03113 -3procedures requires use of explosion-proof equipment and very close control of the reaction conditions in order to reduce potential fire and explosion hazards. For this reason, heretofore it has been preferred to produce the alumoxane by reacting an aluminum alkyl with a hydrated salt, such as hydrated copper sulfate. In such procedure a slurry of finely divided copper sulfate pentahydrate and toluene is formed and mantled under an inert gas.

Aluminum alkyl is then slowly added to the slurry with stirring and the reaction mixture is maintained at room temperature for 24 to 48 hours during which a slow hydrolysis occurs by which the alumoxane is produced.

Although the production of alumoxane by a hydrated salt method significantly reduces the explosion and fire hazard inherent in the wet solvent production method, production of an alumoxane by reaction with a hydrated salt must be carried out as a separate process, is slow, produces hazardous wastes that create disposal problems, and cannot be used for the production of the active catalyst complex in situ in the polymerization vessel because the hydrated salt reagent would become entrained in and contaminate any polymer produced therein.

Only in those situations wherein a hydrated material is of a chemical composition acceptable as a filler material for a filled polyolefin composition may it be used to produce a metallocene/alumoxane catalyst complex in situ as a feature of the polymerization process. Hence U. S. Patent 4,431,788 discloses a process for producing a starch filled polyolefin composition wherein an aluminum 30 trialkyl is first reacted with a starch of a moisture I content below 7 weight percent, which is then treated with a (cyclopentadienyl)-chromium, titanium, vanadium or zirconium alkyl to form a metallocene type catalyst complex on the starch surface. An olefin is then polymerized about the starch particles to form a free-flowing composition of polyolefin-coated starch particles. German Patent 3,240,382 likewise discloses a method for producing a filled polyolefin composition which utilizes the water content of the filler material to WO 89/02448 PCT/US88/03113 -4produce thereon an active metallocene type catalyst compl'ex Polymer is produced at the filler surface to uniformly coat the filler particles.

It would be desirable to devise an economical procedure whereby an active metallocene/alumoxane catalyst species could be safely produced in situ in the polymerization reaction vessel from a catalyst precursor composition of metallocene and aluminum alkyl which procedure is free of the dangers or limitation attendant with the. methods heretofore known for the production of such types of catalyst.

Summary of the Invention The, present invention provides a process for preparing polymers of ethylene, propylene, and copolymers of ethylene and alpha olefins by polymerization in the presence of an active metallocene/alumoxane polymerization catalyst that is safely prepared in situ in the polymerization reaction vessel by subjecting a precursor composition of metallocene and aluminum alkyl to a gaseous monomer feed stream which contains entrained water.

By the process of this invention the active catalyst complex may be prepared in the form of a homogeneous catalyst for solution polymerization or in the form of a hetrogenous catalyst on a catalyst support for use in 25E1 slurry, or gas phase polymerization. When prepared as a homogeneous catalyst, the process comprises supplying an aluminum alkyl and a metallocene to the polymerization solvent in the polymerization vessel in amounts appropriate to form, upon exposure of the aluminum alkyl p2 30 to water, a metallocene/alumoxane catalyst of the desired composition and, thereafter, supplying the polymerization reaction vessel with a monomer containing water vapor in an amount from about 100 to about 10,000 ppm and preferably 1000-8000 ppm to attain the desired degree of catalyst activation. In a continuous polymerization process the water would be fed in continuously with the monomer feed and the desired degree of catalyst activity controlled with the amount of water. In a batch process the water is fed with the monomer feed until the catalyst WO 89/02448 PCT/US88/031 13 obtains the desired activity, generally maximumn activity, and then the water is turned off and only dry monomer is fed into the. reactor. The molar ratio of alumninum alkyl in the catalyst complex to water in the monomer for suitable catalyst activity is generally from about 1 to about 2, preferably from about 1.2 to about 1.4, and most preferably about 1.3.

A heterogeneous catalyst is prepared by first codepositing the requ~isite quantities of an aluminum alkyl and a metallocene from solution by adsorption on a high surface area catalyst support material, such as silica gel, and thereafter exposing the supported catalyst precursor composition to a gaseous monomer supply stream containing entrained water in amounts from about 100 to about 10,000 ppm and preferably 1000-8000 ppm to convert said aluminum alkyl to an alumoxane for formation of the active catalyst complex. When the heterogeneous catalyst is to be used for slurry polymerization the solvent for the codeposition technique may be one suitable for slurry polymerization. In that case, the solvent need not be evacuated and. slurry polymerization can be commenced by supplying to the reaction vessel a monomer feed stream containing entrained water, When the heterogeneous catalyst is to be employed for gas phase polymerization, the codeposition solvent, is evacuated and the catalyst support material containing the adsorbed catalyst precursor composition is dried to a free flowing powder which may then be used in accordance with standard gas phase polymerization techniques with a monomer feed stream containing entrained water which converts the supported precursor composition to the active catalyst complex.

Detailed Description of the Preferred Embodiments The present invention is directed towards a method for preparing catalyst systems and a catalytic process for the polymerization of olefins, and particularly ethylene to high molecular weight polyethylenes such as linear low density polyethylene (LLDPE,) and high density polyethylene ~6 1 WO 89/02448 PCT/US88/03113 (HDPE). The polymers are intended for fabrication into articles by extrusion, injection molding, thermoforming, rotational molding, and the like. In particular, the polymers prepared by the method of this invention are homopolymers of ethylene and copolymers of ethylene with higher alpha-olefins having from 3 to about 10 carbon atoms and preferably 4 to 8 carbon atoms. Illustrative of the higher alpha-olefins are butene-1, hexene-l, and octene-1.

In the process of the present invention, ethylene, either alone or together with alpha-olefins having three or more carbon atoms, is polymerized in the presence of a catalyst system comprising at least one metallocene and an alumoxane, In accordance with this invention, one can also produce olefin copolymers, particularly copolymers of ethylene and higher alpha-olefins having from 3-18 carbon atoms.

The active catalyst complex prepared by the process of this invention comprises a metallocene and an alumoxane. Alumoxanes are polymeric aluminum compounds which can be represented by the general formula (R-Al-O)y which is believed to be a cyclic compound and R(R-Al-0-)yAlR 2 which is a linear compound. In the general formula, is a CI-C 5 alkyl group such as, for example, meethyl thyl, propyl, butyl, and pentyl and "y" is an integer from 2 to about 30. Preferably, is methyl and is about 4 to about 25 and most preferably 6-25, Generally, in the preparation of alumoxanes from, for example, aluminum trimethyl and water, a mixture of linear and cyclic compounds is obtained.

The metallocene may be any of the organometallic coordination compounds obtained as a cyclopentadienyl derivative of a transition metal. Metallocenes which are useful for preparing an active catalytic complex according to the process of this invention are the mono, bi and tri cyclopentadienyl or substituted cyclopentadienyl metal compounds and most. pre.ferably, bi-cyclopentadienyl b WO 89/02448 PCT/US88/03113 compounds. The metallocenes particularly useful in this invention are represented by the general formulas: I. (Cp) mMRnXq wherein Cp is a cyclopentadienyl ring, M is a Group 4b or 5b transition metal and preferably a Group 4b transition metal, R is a hydrocarbyl group or hydrocarboxy group having from 1 to 20 carbon atoms, X is a halogen, and m is as whole number from 1 to 3, n is a whole number form 0 to and q is a whole number from 0 to 3, II. (CsR'k)gR"s(CsR' )MQ3_g, and III. R"s(CsR'k)2MQ' wherein (CsR'k) is a cyclopentadienyl or substituted cyclopentadienyl, each R' is the same or different and is hydrogen or a hydrocarbyl radical such as alkyl, alkenyl, aryl, alkylaryl, or arylalkyl radicals containing from 1 to 20 carbon atoms, a silicon-containing hydrocarbyl radical, or a hydrocarbyl radical wherein two carbon atoms are joined together to form a C 4

-C

6 ring, R" is C 1

-C

4 alkylene radical, a dialkyl germanium or silicone, or an alkyl phosphine or amine radical bridging two (CsR'k) rings, Q is a hydrocarbyl radical such as aryl, alkyl, alkenyl, alkylaryl, or arylalkyl having 1-20 carbon atoms, hydrocarboxy radical having 1-20 carbon atoms or halogen and. can be the same or different, Q' is an alkylidene radical having from 1 to about 20 carbon atoms, s is 0 or 1, g is 0, 1 or 2; when g is 0, s is O; k is 4 when s is 1 and k is 5 when s is 0 and M is as defined above.

Exemplary hydrocarbyl radicals are methyl, ethyl, propyl, butyl, amyl, isoamyl, hexyl, isobutyl, heptyl, octyl, nonyl, decyl, cetyl, 2-ethylhexyl, phenyl, and the like Exemplary alkylene radicals are methylene, ethylene, propylene, and the like. Exemplary halogen atoms include chlorine, bromine and iodine and of these halogen atoms, chlorine is preferred. EXemplary of the

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WO 89/02448 PCI'/US88/031 13 -8alkylidene radicals is inethylidene, ethylidene and propylidene.

Of the metallocenes, zirconocenes and titanocenes are most preferred. Illustrative but non-limiting examples of these metallocenes which can be usefully employed in accordance with this invention are znonocyclopentadieny.

titanocenes such as, cyclopentadienyl titanium trichloride, pentainethylcyclopentadienyl titanium trichloride; bis (cyclopentadlienyl) titanium diphenyl; the carbene represented by the formula Cp 2 Ti=:CH 2 -Al*(CH 3 2 Cl and derivatives of this reagent such as

CP

2 Ti=CH 2 -Al(CH 3 3 (Cp 2 TiCH 2 2

CP

2 TEiCH 2

CH(CH)C,

CP

2 Ti=CHCH 2

CH

2

CP

2 Ti=C1 2 'AIR' I 2 C1, wherein. Cp is a cyc'lopentadienyl or substituted cylope'ntadienyl radical, and RI 1 is an alkyl, aryl, or alkcylaryl radical having from 1-18 carbon atoms; substituted. bis(cp)Ti(IV) I compounds such as bis(indenyl)Ti diphenyl' or dichloride, bis(methylcyclopentadienyl)Ti diphenyl or dihalides and other dihalide complexes; dialkyl, trialkyl, tetra-alkyl and. pen t-alkyj cyclopentadienyl titanium compounds such as bls(l,2-dimethylcyclopentadienyl)Ti dipheriyl or dichloridet bis(l,2-diethylcyclopentadienyl )Ti dipheny. or dichloritde and other dihalide complexes; s'licone~ phosphine, amine or carbon bridged cyclopentadiene compleXes, such as dimethyl silyldicyclopentadienyl titanium~ diphenyl or dichloride, methylenedicyclopentadienyl titanium diphenyl or daichioride and other dihalide complexes and the like.

1' Illustrative but. non-limiting examples of the Szirconocenes which can be usefully employed in accordance with this invention are, cylpnainlzirconium trichloridet pentamethylcyclopentadienyl zirconium trichloride, bis(cyclopentadieny1 )zirconiun diphenyl, b is (cyclopentadi enyl) zirconium dichloride, the al.kyl substituted cyclopentadleones, such as bis'(ethyl.

cycl.opentadienyl.)zirconiUzn dimethyl, bi s (p -phenylpropylyclopeitadieny) )zirconium dimethyl.l ))is (methylcyclopentiidieny) )zirconium dimethylt and dihalid comnplexes of the ibovej- di-alkyl, tri-alkylt WO 89/02448 PCT/US88/031.13 -9tetra-alkyl, and penta-alkyl cyclopentadienes, such as bis (pentazethylcyclopentadienyl zirconium diznethyl, bis 2-dimethylcyclopentadieny 1)zirconiun ~it..y1 bis 3-diethylcyclopentadienyl) zirconium dirnethyl and dihalide complexes of the above; silicone, phosphorus, and carbon bridged cyclopentadiene complexes such as dimethylsilyldicyclopentadienyl zirconium dirnethyl. or, dihalide, methylphosphine dicyclopentadienyl. zirconium dimethyl or dihalide, and methylene dicyclopentadienyl zirconium dimethyl or dihalide, carbenes represented by the formulae CP 2 ,erzCH 2

P(C

6

HF,)

2

CH

3 and derivatives of these compounds such as CP 2 irCzCH(CH 3 )dH 2 1 Bis (cyclopentadienyl hafnium dichloride, 'bi s(cyclopentadienyl~hafnitum dimethyl, bis(cyclopentadienyl)vanadium dichloride and the lile are illustrative of other metallocenes, Heretofore the alumnoxane component of the active catalyst complex has been, separately prepared then added as. such to the inetallocene to form the active catalyst ~o complex, one. procedure heretofore employed for preparing the alumoxane separately is that of contacting water in the form of a moist solvent with a solution of aluminum trial~yl in A suitable organiq solvent such as benzene or aliphatic hydrocarbon. As before noted this procedure is gs attendant with fire and excplosi.on hazards which require~i the use of explosion-proof ogUipment and carefully controlled reaction conditions, In an alternative method heretofore employed for the separate production of alumxoane# an aluminum al~kyl is contacted with a- hy'drat~d o salt, such as hydrated copper sulfate, The method comprised treating A dil~ute, solution of aluminum alkyl int for example, toluene, with a copper sulfate pentahy'drate, A, slow, controlled hydrolysis of the aluminum alk~yl to alumoxane resulted Which sbtantially eliminated the fire 3~and explosion hazard but with the disadvantage of the creation of hazardous waste products that must be disposed of and from which the alunoxne must be separated before it is suitable for: use in~ the production of an active catalyst complex. The procedureg heretofore employed were WO 89/02448 PCT/US88/03113 expensive, time-consuming, potentially dangerous, and were not suitable to the production of an active catalyst species from a metallocene and aluminum alkyl composition in situ in the polymerization reaction vessel.

In accordance with the present invention, an active catalyst complex is produced in situ in the polymerization reaction vessel from a catalyst precursor composition comprising; a- metallocene and an aluminum alkyl. The aluminum alkyl employed is preferably an aluminum trialkyl such as- trimethyl aluminum or triethyl aluminum. In accordance, with, the present invention, the precursor components for a metallocene/alumoxane catalyst, namely a metallocene and an aluminum alkyl, are charged into the polymerization reaction vessel and an active catalyst complex is produced in situ in the reaction vessel by exposing the aluminum alkyl component to water which is entrained in the monomer supplied to the vessel for polymerization, The procedure of the invention allows for the precise control of the rate of production of alumoxane for the active catalyst complex and thereby eliminates the explosion and fire hazards inherent with the reaction of an aluminum alky with water as in the wet solvent method.

Further, the method of the invention avoids the production of hazardous waste products which must be separated from the cal'y.st complex to prevent contamination of the polymer and which must be disposed of as is inherent in the production of alumoxane by treatment of an aluminum alkyl with hydrated salt such as calcif!t sulfate pentahydrate, The procedure of the invent. produces an active catalyst complex required for the polymerization reaction in a much more economical manner in that it eliminates the need to purchase or separately produce alumoxane as such or alternatively to produce alumoxane by procedures and with equipment which are independent of the polymerization reactor itself.

The active catalyst complex producied by the "wet monomer" monomer having entrained water process of this invention may be produced as a homogenous catalyst for solution polymerization, or as a WO 89/02448 PCT/US88/03113 -11heterogeneous supported catalyst for Ll-urry or gas phase polymerization. In any case, catalyst activity is controlled by the degree of alumoxane oligomerization resulting from the reaction between the aluminum alkyl in the catalyst complex and the water in the wet monomer feed. A suitable extent of alumoxane oligomerization and, hence, suitable catalyst activity, is obtained with a molar ratio of aluminum alkyl in the catalyst complex to water in the monomer feed of from about 1 to about 2. A more active catalyst is obtained when the molar ratio of aluminum alky! to water is from about 1.2 to about 1,4, and optimum catalyst activity when the molar ratio is about 1.3.

A homogenous catalyst is produced by supplying to the polymerization solvent contained in a polymerization reaction vessel an aluminum alkyl and a metallocene in amounts appropriate to form, upon exposure of the aluminum alkyl to water, an active catalyst complex composed of the metallocene and an alumoxane and activating the catalyst precuror composition to the active catalyst complex by supplying said reaction vessel with a monomer feed stream containing water vapor in an amount from about 100 to about 10,000 ppm and preferably 1000-8000, at a molar ratio of aluminum alkyl to water of from about 1 to about 2, preferably from about 1.2 to about 1.4, and especially about 1.3, to attain the desired degree of alumoxane oligomerization. The solvents used in the preparation of the catalyst system are inert hydrocarbons, in particular a hydrocarbon that is inert with respect to the catalyst system, such solvents are well known and include, for example, isobutane, butane, pentane, hexane, heptane, octane, cyclohexane, methylcyclohexane, toluene, xylene and the like.

Alternatively, a supported heterogeneous form of catalyst complex is produced by supplying to a solvent contained in a reaction vessel a high surface area catalyst support material, and an aluminum alkyl and a metallocene in amounts appropriate to form upon exposure of the aluminum alkyl to water an active metallocene and WO 89/02448 PCT/US88/03113 -12-

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alumoxane catalyst complex. Thp metallocene and aluminum a-l'kyl are codeposited on the catalyst support material by adsorption from solution or by evaporation of the solvent from a mixture of catalyst support, metallocene and aluminum alkyl. Thereafter the supported catalyst precursor composition is activated and employed in a slurry polymerization process by supplying said reaction vesseL with a monomer containing water vapor in the amount ofj from about 100 to about 10,000 ppm and preferably 1000-8000 until the desired degree of polymerization is attained Alternatively, the solvent may be evacuated from. the vessel and the supported catalyst precursor composition dried to a free-flowing powder which may then be: used in a gas phase polymerization process by supplying to the gas phase reactor a monomer containing water vapor in an amount from about 100 to about 10,000 ppm and preferably 1000-8000. If desired, the dried supported catalyst precursor composition may be charged back into a polymerization solvent for use in a slurry polymerization 20 and activated by supplying to the reaction vessel a monomer containing water vapor in an amount from about 100 to about 10,000 ppm and preferably 1000-8000. The total amount of water should be sufficient to provide a molar ratio of aluminum alkyl to water of from about 1 to about Zf, preferably from about 1.2 to about 1.4, and especially about i.3, to attain the desired degree of alumoxane oligomerization, since metallocene/alumoxane catalysts have their greatest utility in the production of polyethylene, gQ polypropylene, and polymers of ethylene with alpha-olefin comonomers, the monomer for the "wet monomer" feed will preferably be ethylene or propylene, and most preferably ethylene, The requisite amount of water may be conveniently supplied to the monomer feed stream by passing the monomer through a bed of wet silica before its admission to the reaction vessel. The water content of the monomer feed stream may be conveniently monitored and controlled by controlling the amount of makeup water added to the silica bed and by providing a split stream for 11 WO 89/02448 PCT/US88/03113 -13adding, as necessary, a controlled amount of dry monomer to the wet monomer feed stream going to the reactor.

By appropriate selection of the type and relative amounts of the metallocene and the aluminum alkyl catalyst precursor, one can attain by the present method the particular active catalyst complex desired for any particular application. For example, higher concentrations of alumoxane in the catalyst system generally result in higher molecular weight polymer product. Therefore, when it is desired to produce a high molecular weight polymer a higher concentration of aluminum alkyl is used, relative to the metallocene, than when it is desired to produce a lower molecular weight material, The ratio of aluminum in the aluminum alkyl to total metal in the metallocene can be in the range of from about 0.5 1 to about 10,000 1, and preferably about 1 to about 1,000 1 and most preferably 5 1 to 100 1.

As disclosed in copending application Serial No.

0 728,111 filed April 29, 1985, the molecular weight of the polymer product can be controlled by the judicious selection of substituents on the cyclopentadienyl ring and use of ligands for the metallocene. Further, the comonomer content can be controlled by the judicious selection of the metallocene. Hence, by the selection of catalyst components it is possible to tailor the polymer product with respect to molecular weight and density.

Further, one may tailor the polymerization reaction conditions over a wide range of conditions for the production of polymers having particular properties.

In the examples following, the melt index (MI) and melt index ratio (MIR) were determined in accordance with ASTM test D1238.

Examples 1-4 A 2.2 liter autoclave equipped with an incline blade stirrer, an external water jacket for temperature control, a system inlet and vent line and a regulated supply of ethylene and nitrogen, was dried and deoxygenated with a nitrogen flow. 800 ml of dried and deoxygenated hexane WO 89/02448 PCT/US88/03113 -14and 50 ml of hexene-1 was introduced directly into the autoclave. 10 ml of the trimethylaluminum/heptane solution (1.62 M) was injected into the vessel by syringe through the septum inlet. 3.0 mg of bis (n-butyl cyclopentadienyl) zirconium dichloride dissolved in 3.0 ml of toluene was injected into the vessel by syringe. The mixture in the vessel was stirred and heated to the desired temperature. The ethylene feed to the autoclave was supplied through a tube OD x 6" long) packed with a silica gel granule (Shell Silica Spheres S 980A, Shell Oil Company) which was saturated with water. A hydrometer was connected down stream of the silica gel bed to determine the water content in the ethylene feed stream to the autoclave. The autoclave was pressurized with the wet ethylene to the desired total pressure, and the supply of wet ethylene to the autoclave was continued to maintain a constant total pressure. As the polymerization proceeded as wet ethylene supply to the autoclave was maintained at a constant total pressure, ethylene consumption increased with time. The ethylene consumption, profile indicates the rate at which the catalyst was activated as water was carried into the system by the ethylene feed stream.

The above described procedure was carried out at different reaction temperatures, different ethylene partial pressure and different reaction times with the results as indicated in Table I below. In each case the water content of the ethylene feed stream to the autoclave, as determined by hydrometer readings, was 7,000 ppm water, TABLE

I

REACTION

Example Time Temp. Pressure Yield MI No. (Hin.) (psig) (Grams) (dg/min) MIR 1 70 60 60 74 0.8 31.5 2 70 85 60 34 83.4 3 26 60 150 109 0.2 31.5 4 33 85 150 129 1.4 23.4 *J!l mnk1 WO 89/02448 PCT/US88/03113 Example 5-8 Example 1 was repeated except that a water saturated molecular sieve (Type 4A, Union Carbide Corp., Linde Division) column was used to wet the ethylene feed and 400 ml of hexane solvent and 50 ml of butene-1 comonomer were added to the reactor.

The above described -procedure was carried out at different reaction temperatures, different total ethylene partial pressures and different times with the results as indicated in Table II below. In each case the water content of the ethylene feed stream to the autoclave was 4,000 ppm.

TABLE II

REACTION

Example Time Temp, Pressure Yield MI No. (nin.) (psig) (Grams) (dg/min) MIR 40 60 90 39 6 20- 85 150' 36 7 20 60 150 57 8 55 60 60 84 1.7 29,1 Examples 9-11 A 125 ml vial containing a magnetic stirring bar was charged with 5,0 grams of silica gel (Davison 948) that had been dehydrated at 800 0 C, 125 mg of bis (n-butyl cyclopentadienyl) zirconium dichloride was charged into the vial, Thereafter 30 ml of dried and deoxygenated -siw hexane and a selected amount of trimethylaluminum/heptane solution (1.62 M) was charged into the vial and the resulting mixture was stirred at room temperature for minutes. Thereafter the hexane and heptane solvent were evacuated from the vial and the silica gel, codeposited with. (n-Bucp) 2 ZrCd2 and trimethyaluminum, was dried at room. temperature to form a free flowing powder. Three such supported catalyst precursor compositions were prepared by respective use of 15, 10 and 5 ml of trimethylaluminum/heptane solution (1,62 Each such j WO 89/02448 PCT/US88/03113 -16composi'&ion was then used for the gas phase polymerization of ethylene by charging 5.0 grams of the catalyst precursor composition into a vial equipped with a magnetic stirring bar. The vial was then flushed with an ethylene gas containing 1,000 ppm water after which pressure of the wet ethylene feed to the vial was regulated to and maintained at 5 psig for the time that polymerization was allowed to proceed at room temperature. The results of the polymerization reactions are shown in Table III below.

TABLE III Amount TMA Solution Reaction Yield of Example Used For Time Polymer No. Catalyst (hours) (grams) 9 15 ml 4 7.4 10 10 ml 2 5,6 11 5 ml 2 0.1 The invention has been described with reference to its preferred embodiments,. From this description, a person of ordinary skill in the art may appreciate changes that could be made in the invention which do not depart from the scope and spirit of the invention as described above and claimed hereafter.

o.

Claims (5)

1. A process for preparing polymers of ethylene, propylene, and copolymers of ethylene and alpha olefins, respectively by polymerization of the monomer(s) in a reaction vessel in the presence of a metallocene-alumoxane catalyst composition which is formed in situ in said reaction vessel, comprising the steps of: supplying said reaction vessel with an aluminum alkyl and a metallocene in amounts appropriate to form, upon exposure of the aluminum alkyl to water, a metallocene-alumoxane composed of: a metallocene of the formula: (Cp) MR X m n q wherein Cp is a cyclopentadienyl ring, M is a Group 4b or transition metal, R is a hydrocarbyl group or hydrocarboxy group having from 1 to 20 carbon atoms, X is a halogen, and m is a whole number from 1 to 3, n is a whole number form 0 to 3, and g is a whole number from 0 to 3; (C5R'k)gR" (CSR'k)MQ3ag, or R' 1 (CSR'k)2MQ' wherein (CsR k) is a cyclopentadienyl or substituted cyclopentadienyl, each R' is the same or different and is hydrogen or a hydrocarbyl radical containing from 1 tc carbon atoms, a silicon-containing hydrocarbyl radical, or a hydrocarbyl radical wherein two carbon atoms are joined together to form a C 4 -C 6 ring, R" is C 1 -C 4 alkylene radical, a dialkyl germanium or silicone, or an alkyl phosphine or amine radical bridging two (CsR'k) rings, Q is a hydrocarbyl radical having 1-20 carbon atoms, hydrocarboxy radical having 1-20 carbon atoms or halogen and can be the same or different, Q' is an alkylidene radical having from 1 to 20 carbon atoms, s is 0 or 1, g is 0, 1 or 2; when g is 0, s is 0; k is 4 when s is 1 and k is S when s is 0 and M is as defined above; and an alumoxane of the formula (R-Al-0)y for a cyclic alumoxane and R(R-Al-O-) AIR 2 for a linear alumoxane wherein is a number from 2 to 30 and is a alkyl group; and r- WO 89/02448 PCT/US88/03113 -18- supplying said reaction vessel with a monomer containing water at a concentration of from 100 to 10,000 ppm and in an amount sufficient to provide a molar ratio of said aluminum alkyl to said water of from 1 to 2.

2. A method according to claim 1 wherein the aluminum trialkyl and metallocene are supplied to the reaction vessel as a deposit on a catalyst support.

3. A method according to claim 1 or 2 wherein polymerization is performed in a polymerization solvent as a solution or slurry polymerization or in the gas phase. 4, A method according to any of the preceding claims wherein R of the alumoxane formula is methyl or ethyl and is a number from 4 to 25 and/or wherein M of the metallocene formula is a Group 4b transition metal, A method according to any of the' preceding claims wherein the monomer supplied to said reaction vessel contains water vapor in a concentration of from 1,000 to 8,000 ppm and/or wherein the molar ratio is from 1.2 to 1.4 preferably from 1.25 to 1,35, e.g, about 1,3, 6, A process for preparing an active metallocene-alumoxane catalyst in situ in a reaction vessel during slurry or solution polymerization of ethylene and alpha olefin monomers, comprising the steps of; charging to said reaction vessel quantities of an aluminum trialkyl and a metallocene sufficient to form upon exposure of the aluminum trialkyl to water a metallocene-alumoxane composition comprisingt i WO 89/02448 PCT/US88/031 13 -19- a metallocene of the formula: (Cp) MR X mnq wherein Cp is a cyclopentadienyl ring, M is a Group 4b or transition metal, R is a hydrocarbyl group or hydrocarboxy group having from 1 to 20 carbon atoms, X is a halogen, and m is a whole number from 1 to 3, n is a whole number form 0 to 3, and q is a whole number from 0 to T; (CR' 09 Rif (CSlk)Q-g or R(CSRk )2MQI wherein (CsPR 2 k) is a cyclopentadienyl or substituted cyclopentadienyl, each RI is the same or different and is hydrogen or a hydrocarbyl radical contaiiting from 1 to 20 carbon atoms, a silicon-containing hydrocarbyl radical,, or ahydrocarbyl radical wherein two carbon atoms are joined together to form a C 4 -C 6 ring, Rif is C 1 -C4 alkyene radical, a dial~y1 germanium or silicone, or~ an a],kyl phosphine or amine radical bridging two (CSR'Q) rings, Q is a hydrocarbyl radical having 1-20 carbon atoms, hydrocarboxcy radical having 1-20 carbon atoms or halogen and can be the same or different, Q1 is an alkylidlene radical having from, 1, to carbon atoms, s is 0 or J1, g, is 0, 1 or 2; when~ g i s, 0, s is 0; k~ is 4 when s is 1 and X Is 5 when s is 0 and M1 is as defined above; and an alumo~ane of the formuliJa (R-Al-O) for a cyclic alumoxane and R(R-Al-O-) AlR 2 for a linear aumpoxane whereini is a number from 2to 30 and R, is a CI-5 alk~yl group- and supplying to said reaction vessel, a rmonomer which contains from 100 to 10(000 ppm water at, f-a molar ratio of said aluminum trialkyl to said water of from I1 to 2 to convert said aluminum trialkyl to an alumoxane for formation of the metalliocene-alumoxane catalyst, composition. 1. A process for preparing polymers of ethylene, propylene, and copolymers of ethylene and alpha olefins, respectively by polymerization of the. monom~er(s) in a reaction vessel In the presence of a motallocene-atumoxanie Catalyst composition which Is activated in IWt in, said reaction, vessel, comprising the teps, of:, WO 89/02448 PCT/US88/03113 supplying said reaction vessel with an aluminum alkyl and a metallocene in amounts appropriate to form, upon exposure of the aluminum alkyl to water, a metallocene-alumoxane catalyst; and supplying said reaction vessel with a monomer containing from 100 to 10,000 ppm water vapor at a molar ratio of aluminum alkyl to water of from 1 to 2. 8, A process for preparing an active metallocene-alumoxane catalyst in situ in a reaction vessel during slurry or solution polymerization of ethylene and alpha olefin monomer, comprising the steps of: charging to said reaction vessel quantities of an aluminum alkyl and a metallocene sufficient to form, upon exposure of the aluminum alKyl to water, a metallocene-alumoxane catalyst; and supplying to said reaction vessel a gaseous'monomer which 'contains from 100 to 10,000 ppm water at a molar ratio of said aluminum alkyl in said charge to said water vapor in said monomer of from about 1 to about 2 to convert said aluminum alkyl to an alumoxane for formation of the metallocene-alumoxane catalyst composition, ana expiosion nazara Duc wi-cn ne aisaavaritaye o.L L i creation of hazardous waste products that must be disposed of and from which the alumoxane must be separated before it is suitable for use in the production of an active catalyst complex. The procedures heretofore employed were INTERNATIONAL SEARCH REPORT PrnhT/Tc2 gQA/0113 I. CLASSIFICATION OF SUNJECr MATTER (it several classific3tion symibols aply, indicatea sll According t0 Inernational Patent Classification CPC) of to both National Classification and IPC IPC 4 C 08 F 10/00; C 08 F 4/62, 11, FIELDS SEARCHED Minimum Documentation SearchedI Classification System Classificatlon Symbols PC 4 I CO08 F Documentation Searched other than Minimum Documentation to the Extent that such Documents are included In the Platds SearchedI III, DOCUMENTS CONSIDERED TO MEU RLEVANT' CategorY' Citation of Document, It with Indication, whveeappropriate, ot the istevant Passages 1; IReicyanit to Claim No4 YFR,, A, 1173577 (F'ARBWERKE HOECHIST) 26 February 19591 see claims; example 2 Y DE, Air Z608863 (BASF AG)1 8 September' 1977 see claims cited in the appliation A DEr A, 3240382 (HOECHiST) 3 May 1984 cited in the applicaiozi A EP, A, 0037894 (CPC INTERNATXQNAL) 1 21 October 1981 see claims~ cited in, the applicationl 0' SOC4 5pei0(dalqoie. of cited doumci 10ntstOT" Iltrdocument published a#ter the internationral filing da~te document definIng the general state ot the art which Is noat of Priority dote and flotintofl iiict with the appl6CAtion but Q ited to lI thela in. lolise or theory underlying the oons111lddto be Of Perl~ar tvfice Inentia What l.~documnent but published en of caffr the intofrt tnef docum~of pa tldutef (f 10*vf4e:the claiei nvefliak filing dte cannot be coniiered n avel Of4r nnt cc 0 sgored Pfo 1 s"d~ililif which may throw double On ariority Claim(s) 0( Invlqve ort Inventive silo which is cited to establish the Publictionl dat4 at anothier mum of o flitile fia vr~ttecemditet citaion r oner necrl ~a~qf (ccapeifie) cnnoi a*ccoosrta 0Involve an inventive step whern the document fetrtng to an oral C1iollscu is ehblilon I00of deocumqnt ts *ombimed with one oorre olot h e tv Ot Wte( lti5sa9inene, sAW 10Mcombtnliqn tiobing oovious to e4 Person siiittd "ll" 06dument Sutlille*d sPO? t0the tlen4l610fiig d but Inth ~e arm, later then the priority dts claimed docut tMember of the seime Patenttfamily IV, Pale of the Aolusl Cometetton of the Womteti~l I304141) Cataoof Millinfg at this Intotarlint Ieafch Report Novambe 19881, 3 0 EC 1988 Infolt lnl I avChing Authority L 1lnt~ EUIR0PEM ~PATENT O0FIZ 0-r .VkI I- t IN MDfWgIR form I"011115A11tota cnd ahet) (Jnuy 144) ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTEPNATIONAL PATENT APPLICATION NO. US 8803113 SA 24342 This 4nnex lists the- patent faimily members~ relating to the patent documents cited in the abov'e-mientioned international search report. The memb-,rs are as contained in the European, Patent Offl- EDP file on 05/112188 The Europcein Patent Office is, in no way' liable for these particulars which are merely given for the purpose of informnation. Patent document.I Publicato Patent family Publication c ited in search report I daem brs) dt FR-A- 1173577 None OE-A- 2608863 08-09-77 None DE-A- 3240382 03-05-84 None EP-A- 0037894 Z1-10-81 DE-A,CQ JP-A- AU-A- CA'-A- US-A- All-B- 3007433 56135509 6755281 1166384 4431788 546856 03-09-81

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