NO309657B1 - Use of metallocene compounds in olefin polymerization - Google Patents

Description

The present invention relates to the use of metallocene compounds and more specifically certain transition metal compounds group IVB in the periodic table by olefin polymerization of ethylene and a monomer selected from a C3-C20 alpha-olefin or a C5-C20<d>ioolefin.

As is well known, various processes and catalysts exist for the homopolymerization or copolymerization of olefins. For many applications, it is of utmost importance for a polyolefin to have a high weight average molecular weight while also having a relatively narrow molecular weight distribution. A high weight average molecular weight, when accompanied by a narrow molecular weight distribution, provides a polyolefin or an ethylene-α-olefin copolymer with high strength properties.

Traditional Ziegler-Natta catalyst systems—a transition metal compound cocatalyzed with an aluminum alkyl compound—are capable of producing polyolefins that have a high molecular weight but a broad molecular weight distribution.

Recently, a catalyst system has been developed in which the transition metal compound has two or more cyclopentadienyl ring ligands, where such a metal compound is termed a metallocene, which catalyzes the production of olefin monomers into polyolefins. Accordingly, metallocene compounds of group IVB metals, especially titanocene and zirconocene, have been used as the transition metal component in such a "metallocene"-containing catalyst system for the production of polyolefins and ethylene-α-olefin copolymers. When such metallocenes are cocatalyzed with an aluminum alkyl - as is the case with a traditional type Ziegler-Natta catalyst system - the catalytic activity of such a metallocene catalyst system is usually too low to be of any commercial interest.

It has since been found that such metallocenes can be cocatalyzed with an alumoxane compound, instead of an aluminum alkyl compound, to provide a high activity metallocene catalyst system that catalyzes the production of polyolefins.

A number of different group IVB transition metal compounds of the metallocene type have been suggested as possible candidates for an alumoxane cocatalyzed catalyst system. Although bis(cyclopentadienyl) group IVB transition metal compounds have been the most preferred and extensively investigated type of metallocenes for use in metallocene/alumoxane catalysts for polyolefin production, it has been suggested that mono- and tris(cyclopentadienyl) transition metal compounds also may be useful. See, e.g. U.S. Patents 4,522,982, 4,530,914, and 4,701,431. Such mono(cyclopentadienyl) transition metal compounds that have been proposed heretofore as candidates for a metallocene/alumoxane catalyst are mono(cyclopentadienyl) transition metal trihalides and

—trialkyls.

More recently, International Publication No. WO 87/03887 describes the use of a composition comprising a transition metal coordinated to at least one cyclopentadienyl and at least one heteroatom ligand as a metallocene-type component for use in a metallocene/alumoxane catalyst system for α-olefin polymerization. The compound is broadly defined as a transition metal, preferably in group IVB in the periodic table, which is coordinated with at least one cyclopentadienyl ligand and one to three heteroleoligands, the rest of the coordination need being satisfied with cyclopentadienyl or hydrocarbyl ligands. The described metallocene/alumoxane catalyst system is illustrated solely with reference to transition metal compounds which are bis(cyclopentadienyl) group IVB transition metal compounds.

Even more recently, at the Third Chemical Congress of North America held in Toronto, Canada, June 1988, John Bercaw reported attempts to use a group IIIB transition metal compound coordinated to a simple cyclopentadienyl heteroatom-bridged ligand as a catalyst system for polymerization of olefins. Although some catalytic activity was observed under the conditions used, the degree of activity and the properties observed in the resulting polymer product were discouraging for a belief that such a transition metal compound could usefully be used for commercial polymerization processes.

According to the present invention, the use of a metallocene compound (I) of the general formula is provided:

where:

M is Zr, Hf or Ti;

(C5H5_y_x_Rx) is a cyclopentadienyl ring substituted with from 0 to 5 R groups, "x" is 0, 1, 2, 3, 4 or 5 denoting the degree of substitution, and each R is independently a

radical selected from C±—C2o-hydrocarbyl radicals, substituted C^—C2o-hydrocarbyl radicals where one or more hydrogen atoms are replaced by a halogen atom, Cy-C20~hydrocarbyl-substituted metalloid radicals where the metalloid is selected from group IVA in the periodic table and halogen radicals;

(JR'Z_1_V) is a heteroatom ligand where J is an element with a coordination number of 3 from group VA or an element with a coordination number of 2 from group VIA of the periodic table, each R' is independently a radical selected from C-j— C20- hydrocarbyl radicals, substituted Cj — C20~hydrocarbyl radicals where one or more hydrogen atoms have been replaced by a halogen atom, and "z" is the coordination number of the element J;

each Q or Q' is independently halogen, hydride or a substituted or unsubstituted C 1 -C 20 hydrocarbyl, alkoxide, aryloxide, amide, arylamide, phosphide or arylphosphide provided that when Q or Q' is a hydrocarbyl such Q or Q' is different from C5<H>5_V_XRX or both Q and Q' together are an alkylidene or cyclometalated hydrocarbyl and M' has the same meaning as M;

"y" is 0 or 1 when w is greater than 0; y is 1 when w is 0, when "y" is 1 then B is a covalent bridging group containing a Group IVA or VA element, and

L is a neutral Lewis base where "w" denotes a number from 0 to 3,

in olefin polymerization of ethylene and a monomer selected from a C3-C20 cx-olefin or a C5-<C>20<d>ioolefin,

except :

(i) polymerization of ethylene and vinyl aromatic monomer, and (ii) when compound (1) is (N-t-butylamino)(dimethyl)(n<5->

2,3,4,5-tetramethylcyclopentadienyl)silane zirconium-

dichloride, polymerization of ethylene and 1-hexene or 4-methyl-1-pentene.

Preferred features of this application according to the invention appear from the accompanying claims 2 and 3.

A catalyst system which allows the production of polyolefins of higher molecular weight and with a narrow molecular weight distribution is described in NO patent 178,895. This catalyst system includes a transition metal component from group IVB in the periodic table (CRC Handbook of Chemistry and Physics, 68th edition, 1987-1988) of the type used according to the present invention together with an alumoxane component, and can be used in solution, slurry or bulk phase polymerization method for producing a polyolefin of high weight average molecular weight and relatively narrow molecular weight distribution.

The alumoxane component in the catalyst can be represented by the formulas: (R<2->Al-0)m; R<3>(R<4->Al-0)m-AlR<5> or mixtures thereof, where R<2->R<5> is independently a monovalent, anionic ligand such as a C-j-C5-alkyl group or halide and "m" is an integer ranging from 1 to 50 and is preferably from 13 to 25.

A catalyst system of the above type can be prepared by placing the group IVB transition metal component, i.e. the metallocene compound (I), and the alumoxane component in common solution in a normal liquid alkane or aromatic solvent, which solvent is preferably suitable for use as a polymerization diluent for the liquid phase polymerization of a olefin monomer.

A typical polymerization process in which the present application utilizes, namely polymerization or copolymerization of olefins, involves the placement of ethylene or C3—C20-°<-olefins alone or with other unsaturated monomers including C3—C20~a-Olef iners or C5—C20_ciiolef iners, in contact with a catalyst comprising, in a suitable polymerization diluent, the group IVB transition metal component ie the metallocene compound, as defined above; and a methylalumoxane in an amount to provide an aluminum to transition metal molar ratio of from 1:1 to 20,000:1 or more; and reacting such a monomer in the presence of such a catalyst system at a temperature of from -100 to 300°C for a time of from 1 second to 10 hours, thereby forming a polyolefin having a weight average molecular weight of from 1,000 or less to 5,000 000 or more and a molecular weight distribution from 1.5 to 15.0.

Lower molecular weight compounds can be prepared using catalyst materials of reduced activity; higher temperatures and/or the use of transfer agents such as hydrogen.

Examples The B group which is suitable as a constituent group in the Group IVB transition metal component ie in the metal coene compound is identified in column 1 of Table 1 under the heading "B".

Examples of hydrocarbyl radicals for Q are methyl, ethyl, propyl, butyl, amyl, isoamyl, hexyl, isobutyl, heptyl, octyl, nonyl, decyl, cetyl, 2-ethylhexyl, phenyl and the like, methyl being preferred. Examples of halogen atoms for Q include chlorine, bromine, fluorine and iodine, chlorine being preferred. Examples of alkoxides and aryloxides for Q are methoxide, phenoxide and substituted phenoxides such as 4-methylphenoxide. Examples of amides for Q are dimethylamide, diethylamide, methylethylamide, di-t-butylamide, diisopropylamide and the like. Examples of arylamides are diphenylamide and any other substituted phenylamides. Examples of phosphides for Q are diphenyl phosphide, dicyclohexyl phosphide, diethyl phosphide, dimethyl phosphide and the like. Examples of alkyldiene radicals for both Q together are methylidene, ethylidene and propylidene. Examples of the Q group suitable as a constituent group or element of the metallocene compound (I) are identified in column 4 of Table 1 under the heading

"Q".

Suitable hydrocarbyl and substituted hydrocarbyl radicals which, as an R group, can be used instead of at least one hydrogen atom in the cyclopentadienyl ring, will contain from 1 to 20 carbon atoms and include straight and branched alkyl radicals, cyclic hydrocarbon radicals, alkyl substituted. cyclic hydrocarbon radicals, aromatic radicals, alkyl-substituted aromatic radicals and cyclopentadienyl rings containing one or more fused, saturated or unsaturated rings. Suitable organometallic radicals which, as an R group, can be used instead of at least one hydrogen atom in the cyclopentadienyl ring include trimethylsilyl, triethylsilyl, ethyldimethylsilyl, methyldiethylsilyl, triphenylgermyl, trimethylgermyl and the like. Examples of cyclopentadienyl ring groups (C5H5_y_xRx) suitable as a constituent group in the Group IVB transition metal component of the catalyst system are identified in column 2 of Table 1 under the heading (C5H5_y_x<R>x).

Suitable hydrocarbyl and substituted hydrocarbyl radicals which, as an R' group, may be used in place of at least one hydrogen atom in the heteroatom-J ligand group, will contain from 1 to 20 carbon atoms and include straight and branched alkyl radicals, cyclic hydrocarbon radicals, alkyl substituted cyclic hydrocarbon radicals, aromatic radicals and alkyl substituted aromatic radicals. Examples of heteroatom ligand groups (JR'z_^_y) suitable as a constituent group of the Group IVB transition metal component of the catalyst system are identified in column 3 of Table 1 under the heading (JR'z-i-y).

Table 1 shows representative constituent groups for the group IVB transition metal component ie the metallocene compound

(I), and the list is for illustrative purposes only and should not be seen as limiting in any way. A number of final components can be formed by permuting all possible combinations of the component groups with each other. Illustrative compounds are: dimethylsilyltetramethylcyclopentadienyl-tert-butylamido-zirconium dichloride, dimethylsilyltetramethylcyclopentadienyl-tert-butylamidohafnium dichloride, dimethylsilyl-tert-butyl-cyclopentadienyl-tert-butylamido-zirconium dichloride, dimethylsilyl-tert-butylcyclopentadienyl-tert-butylamido-hafnium dichloride, dimethylsilyltrimethylsilylcyclopentadienyl -tert-butylamidozirconium dichloride, dimethylsilyltrimethylcyclopentadienylphenylamidozirconium dichloride, dimethylsilyltetramethylcyclopentadienylphenylamidohafnium dichloride, methylphenylsilyl-tetramethyl cyclopentadienyl-tert-butylamidozirconium dichloride, methyl f eny 1 s i lyl te trame tyl cyclopen t adienyl-ter t-butyl lami do-hafnium dichloride, methylphenylsilyltetramethylcyclopentadienyl-tert-butylamidohafnium dimethyl, dimethylsilyltetramethyl-cyclopentadienyl-p-n-butylpheny 1 am i doz i rconium dichlor i d , dimethylsi ly 1 te trame ty 1 cycl open tad i eny 1-p-n-butylph enylamido-hafnium dichloride. For illustrative purposes, the compounds listed above and those permuted from Table 1 will not include the Lewis base ligand (L). The conditions under which complexes containing Lewis base ligands such as ether or those forming dimers are obtained are determined by the steric bulk of the ligands around the metal center. For example, the t-butyl group in Me2Si(Me4C5)(N-t-Bu)ZrCl2 has greater steric needs than the phenyl group in Me2Si{Nie^C^)(NPh)ZrCl2"Et20 whereby ether coordination in the former compound is not allowed. Likewise, due to the decreased the steric mass of the trimethylsilylcyclopentadienyl group in [Me2Si(Me3SiC5H3 )-(N-t-Bu)ZrCl2l2 in relation to that of the tetramethylcyclopentadienyl group in Me2Si (Me^s ) (N-t-Bu )ZrCl2 , then the former compound is dimeric and the latter is not.

In general, the bridged types of the group IVB transition metal compound ("y" = 1) are preferred. These compounds can be prepared by reacting a cyclopentadienyllithium compound with a dihalide compound, whereby a lithium halide salt is released and a monohalogen substituent is covalently bound to the cyclopentadienyl compound. The thus substituted cyclopentadienyl reaction product is then reacted with a lithium salt of a phosphide, oxide, sulphide or amide (for illustrative purposes a lithium amide) whereby the halogen element in the monohalogen substituent group in the reaction product reacts so that a lithium halide salt is released and the amine part of the lithium amide salt becomes covalently bound to the substituent in the cyclopentadienyl reaction product. The resulting amine derivative of the cyclopentadienyl product is then reacted with an alkyllithium reagent whereby the labile hydrogen atoms, at the carbon atom in the cyclopentadienyl compound and at the nitrogen atom in the amine moiety which is covalently bound to the substituent group, react with the alkyl group in the lithium alkyl reagent to liberate the alkane and form a lithium salt of the cyclopentadienyl compound. The bridged types of the group IVB transition metal compound are then prepared by reacting the dilithium salt cyclopentadienyl compound with a group IVB transition metal, preferably a group IVB transition metal halide.

Non-bridged versions of the group IVB transition metal compound (metallocene compound I) can be prepared from the reaction of a cyclopentadienyl lithium compound and a lithium salt of an amine with a group IV transition metal halide.

Suitable Group IV transition metal compounds which can be used in the catalyst system include those bridged compounds ("y" = 1) where the B-group bridge is a dialkyl, diaryl or alkylaryl silane, or methylene or ethylene. Examples of the more preferred types of bridged group IVB transition metal compounds are dimethylsilyl, methylphenylsilyl, diethylsilyl, ethylphenylsilyl, diphenylsilyl, ethylene or methylene bridged compounds. Most preferred of the bridged compounds are dimethylsilyl, diethylsilyl and methylphenylsilyl bridged compounds.

Suitable Group IVB transition metal compounds that illustrate the non-bridged ("y" = 0) compounds that can be used in the present catalyst systems are exemplified by pentamethyl cycl open tad i eny Idi - t -butyl f osphinodimethylhafnium; pentamethylcyclopentadienyldi-t-butylphosphinomethylethylhafnium; cyclopentadienyl-2-methylbutoxidedimethyltitanium.

To illustrate types of the Group IVB transition metal component, any combination of the groups in Table 1 may be chosen. An example of a bridging compound would be dimethylsilylcyclopentadienyl-t-butylamidodichlorozirconium; an example of a non-bridged compound would be cyclopentadienyldi-t-butylamidodichlorozirconium.

The alumoxane component in the catalyst system is an oligomer compound that can be represented by the general formula (R<2->Al-0)m which is a cyclic compound, or can be R<3>(R<4->Al-0-) m-AlR[j which is a linear compound. An alumoxane is generally a mixture of both the linear and the cyclic compound. In the general alumoxane formula, R<2>, R<3>, R<4> and R<5> are independently a monovalent anionic ligand such as a C-j - C5 alkyl radical, e.g. methyl, ethyl, propyl, butyl, pentyl or halide and "m" is an integer from 1 to 50. Most preferably, R<2>, R<3>, R<4> and R<5> are each methyl and " m" is at least 4. When an alkyl aluminum halide is used in the preparation of alumoxane, one or more of R<2->R^ can be a halide.

As is now well known, alumoxanes can be produced using various methods. E.g. a trialkylaluminum compound can be reacted with water, in the form of a moist, inert organic solvent; or the trialkylaluminum compound can be contacted with a hydrated salt such as hydrated copper sulfate suspended in an inert organic solvent to form an alumoxane compound. In general, however, the reaction of a trialkylaluminum compound with a limited amount of water gives a mixture of both the linear and cyclic compounds of alumoxane.

Suitable alumoxanes that can be used in said catalyst systems are those produced by hydrolysis of an alkyl aluminum reagent such as trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, dimethylaluminum chloride, diisobutylaluminum chloride, diethylaluminum chloride and the like. The most preferred alumoxane for use is methylalumoxane (MAO), particularly methylalumoxanes having a reported average degree of oligomerization of 4 to 25 ("m" = 4 to 25), with a range of 13 to 25 being most preferred.

Catalyst tanks

A catalyst system may include an alkyl aluminum compound and water which may react at least partially with each other and/or with the metallocene compound outside a polymerization vessel for what may be an in situ reaction in the polymerization vessel.

The catalyst systems used in the olefin polymerization comprise a complex formed by mixing the group IVB transition metal component with an alumoxane component. The catalyst system can be prepared by adding the prescribed group IVB transition metal and alumoxane components to an inert solvent in which olefin polymerization can be carried out by a solution, slurry or bulk phase polymerization method.

The catalyst system can conveniently be prepared by placing the defined group IVB transition metal component and said alumoxane component, in any order of addition, in an alkane or aromatic hydrocarbon solvent, preferably one which is also suitable for use as a polymerization diluent. When the hydrocarbon solvent used is also suitable for use as a polymerization diluent, the catalyst system can be prepared in situ in the polymerization reactor. Alternatively, the catalyst system can be prepared separately, in concentrated form, and added to the polymerization diluent in a reactor. On the other hand, if desired, the components of the catalyst system can be prepared as separate solutions and added to the polymerization diluent in a reactor, in appropriate proportions, as is suitable for a continuous liquid polymerization reaction method. Alkane and aromatic hydrocarbons suitable as solvents for forming the catalyst system and also as a polymerization diluent are exemplified by, but not necessarily limited to, straight and branched hydrocarbons such as isobutane, butane, pentane, hexane, heptane, octane and the like, cyclic and alicyclic hydrocarbons such as cyclohexane, cycloheptane, methylcyclohexane, methylcycloheptane and the like, and aromatic and alkyl substituted aromatic compounds such as benzene, toluene, xylene and the like. Suitable solvents also include liquid olefins which can act as monomers or comonomers including ethylene, propylene, 1-butene, 1-hexene and the like.

When used in accordance with the present invention, optimum results are usually obtained when the metallocene compound is present in the polymerization diluent at a concentration of from 0.0001 to 1.0 mmol/liter of diluent and the alumoxane component is present in an amount to provide a molar ratio of aluminum to transition metal of from 1:1 to 20,000:1. Sufficient solvent should be used to thereby provide sufficient heat transfer away from the catalyst components during the reaction and to allow good mixing. The catalyst system components, i.e., the group IVB transition metal compound (metallocene compound I), the alumoxane compound, and the polymerization diluent may be added to the reaction vessel in a rapid or slow manner. The temperature maintained during the contact between the catalyst components can vary greatly, such as e.g. from -10 to 300°C. Higher or lower temperatures can also be used. During the formation of the catalyst system, the reaction mixture is preferably kept within a temperature of approx.

25 to 100°C, most preferably 25°C.

At all times, the individual catalyst system components as well as the catalyst system once formed are protected against oxygen and moisture. The reactions are therefore carried out in an oxygen- and moisture-free atmosphere and, when the catalyst system is recovered separately, it is recovered in an oxygen- and moisture-free atmosphere. The reactions are therefore preferably carried out in the presence of an inert dry gas such as e.g. helium and nitrogen.

Polymerization process

In a preferred embodiment, the catalyst system is used in liquid phase (slurry, solution, suspension or mass phase and combination thereof), high pressure fluid phase or gas phase polymerization of an olefin monomer. These processes can be used alone or in series. The liquid phase process comprises the steps of placing an olefin monomer in contact with the catalyst system in a suitable polymerization diluent and reacting said monomer in the presence of the catalyst system for a time and at a temperature sufficient to yield a high molecular weight polyolefin.

The monomer for such a process may comprise ethylene alone, to produce a homopolyethylene, or ethylene in combination with an α-olefin having 3-20 carbon atoms to produce an ethylene-α-olefin copolymer. Homopolymers of higher α-olefins such as propylene, butene, styrene and copolymers thereof with ethylene and/or C4 or higher α-olefins and C5-C20 diolefins can also be prepared. Conditions most preferred for homo- or copolymerization of ethylene are those whereby ethylene is placed in the reaction zone at a pressure of from 0.131 to 344,750 kPa abs. and the reaction temperature is maintained at from -100 to 300°C. The molar ratio of aluminum to transition metal is preferably from 1:1 to 18,000:1. A preferred range would be from 1:1 to 1,000:1. The reaction time is preferably from approx. 1 min. to approx. 1 hour. A polymerization process using a catalyst system including the metallocene compound defined above can be carried out as follows: In a stirred tank reactor, liquid 1-butene monomer is introduced. The catalyst system is introduced via nozzles in either the vapor or liquid phase. Ethylene gas supply is either introduced into the vapor phase of the reactor or injected into the liquid phase as is well known in the art. The reactor contains a liquid phase consisting essentially of liquid 1-butene together with dissolved ethylene gas, and a vapor phase containing vapors of all monomers. The reactor temperature and pressure can be regulated via reflux of evaporating α-olefin monomer (auto-cooling), as well as by means of cooling coils, jackets, etc. The rate of polymerization is regulated by means of the concentration of catalyst. The ethylene content of the polymer product is determined by the ratio of ethylene to 1-butene in the reactor, which is regulated by manipulating the relative feed rates of these components to the reactor.

Examples

In the examples illustrating the preparation of the metallocene compound (I) used, as well as the present application, the analytical techniques described below were used for analysis of the resulting polyolefin products. Molecular weight determinations of polyolefin products were made by gel permeation chromatography (GPC) in accordance with the following techniques. Molecular weights and molecular weight distributions were measured using a Waters 150 gel permeation chromatograph equipped with a differential refractive index (DRI) detector and a Chromatlx KMX-6 direct coupled light scattering photometer. The system was operated at 135°C with 1,2,4-trichlorobenzene as the mobile phase. Shodex (Showa Denko America, Inc.) polystyrene gel columns 802, 803, 804 and 805 were used. This technique is discussed in "Liquid Chromatography of Polymers and Related Materials III", J. Cazes, publisher, Marcel Dekker, 1981, p. 207. No corrections for column scattering were used; data for generally accepted standards, e.g. However, National Bureau of Standards Polyethylene 1484 and anionically prepared hydrogenated polyisoprenes (an alternating ethylene-propylene copolymer) showed that such corrections to Mw/Mn (= MV/D) were less than 0.05 units. Mw/Mn was calculated from elution times. The numerical analyzes were performed using the commercially available Beckman/CIS marketed LALLS software in conjunction with standard gel permeation packing, run on an HP 1000 calculator.

All procedures were performed under an inert atmosphere of helium or nitrogen. Choice of solvent is often optional, and e.g. in most cases either pentane or 30-60 petroleum ether can be used interchangeably. The lithium-containing amides were prepared from the corresponding amines and either n-BuLi or MeLi. Published methods for the preparation of LiHC5Me4 include CM. Fendrick et al., Organometallics, 3. 819, (1984) and F.H. Kohler and K.H. Doll, Z. Naturforsch., 376, 144 (1982). Other lithiated substituted cyclopentadienyl fluor compounds are typically prepared from the corresponding cyclopentadienyl ligand and n-BuLi or MeLi, or by reaction of MeLi with the appropriate fulvene compound. ZrCl 4 and HfCl 4 were purchased from either Aldrich Chemical Company or Cerac. Amines, silanes, and lithium reagents were purchased from Aldrich Chemical Company or Petrarch Systems. Methylalumoxane was supplied by either Sherring or Ethyl Corp.

EXAMPLES A-L CONCERNING METALLOCENE COMPOUNDS (I) (GROUP IVB-0 TRANSITION METAL COMPONENTS)

Example A

Compound A:

Part 1. Me4HC5Li (10.0 g, 0.078 mol) was slowly added to a Me 2 SiCl 2 (11.5 mL, 0.095, in 225 mL tetrahydrofuran (THF) solution). The solution was stirred for one hour to ensure complete reaction. The THF solvent was then removed via a vacuum to a cold trap maintained at -196°C. Pentane was added to precipitate LiCl. The mixture was filtered through Celite. The solvent was removed from the filtrate. Me4HC5SiMe2Cl (15.34 g, 0.071 mol) was recovered as a pale yellow liquid.

Part 2. Me4HC5SiMe2Cl (10.0 g, 0.047 mol) was slowly added to a suspension of LiHN-t-Bu (3.68 g, 0.047 mol, ~100 mL THF). The mixture was stirred overnight. The THF was then removed via a vacuum to a cold trap maintained at -196°C. Petroleum ether (5:100 mL) was added to precipitate LiCl. The mixture was filtered through Celite. The solvent was removed from the filtrate. Me 2 Si(Me 4 HC 5 )(HN-t-Bu) (11.14 g, 0.044 mol) was isolated as a pale yellow liquid.

Part 3. Me 2 Si(Me 4 HC 5 )(HN-t-Bu) (11.14 g, 0.044 mol) was diluted with slOO ml Et 2 O. MeLi (1.4 M, 64 mL, 0.090 mol) was slowly added. The mixture was allowed to stir for 1 hour after the final addition of MeLi. The ether was reduced in volume before filtering off the product. The product, [Me2Si(Me4C5)(N-t-Bu)]Li2, was washed with several small portions of ether and then vacuum dried.

Part 4. [Me 2 Si(Me 4 C 5 )(N-t-Bu)]Li 2 (3.0 g, 0.011 mol) was suspended in =sl50 mL Et 2 O. ZrCl 4 (2.65 g, 0.011 mol) was slowly added and the resulting mixture was stirred overnight. The ether was removed via a vacuum to a cold trap maintained at -196°C. Pentane was added to precipitate the LiCl. The mixture was filtered through Celite twice. The pentane was significantly reduced in volume and the pale yellow solid was filtered off and washed with solvent. Me2Si(Me4C5)(N-t-Bu)ZrCl2 (1.07 g, 0.0026 mol) was recovered. Additional Me2Si(Me4C5)(N-t-Bu)ZrCl2 was recovered from the filtrate by repeating the recrystallization method. Total yield , 1.94 g (0.0047 mol).

Example B

Compound B:

The same procedure as in Example A for the preparation of compound A was followed with the exception of adding HfCl4 instead of ZrCl4 in part 4. Thus, when [Me2Si(Me4C5 )-(N-t-Bu)]Li2 (2.13 g, 0, 0081 mol) and HfCl 4 (2.59 g, 0.0081 mol) were used, then Me 2 Si(Me 4 C 5 )(N-t-Bu)HfCl 2 (0.98 g, 0.0020 mol) was prepared.

Example C

Compound C:

Part 1. Me 2 SiCl 2 (7.5 mL, 0.062 mol) was diluted with 30 mL of THF. A solution of t-BuH 4 C 5 Li (7.29 g, 0.056 mol, 100 ml THF) was added slowly and the resulting mixture was stirred overnight. THF was removed via a vacuum to a trap maintained at -196°C. Pentane was added to precipitate LiCl and the mixture was filtered through Celite. The pentane was removed from the filtrate leaving a pale yellow liquid, t-BuH 4 C 5 SiMe 2 Cl (10.4 g, 0.048 mol).

Part 2. To a THF solution of LiHN-t-Bu (3.83 g, 0.048 mol,

s:125 mL) T-BuH 4 C 5 SiMe 2 Cl (10.4 g, 0.048 mol) was added dropwise. The resulting solution was stirred overnight. THF was removed via a vacuum to a trap maintained at -196°C. Pentane was added to precipitate LiCl and the mixture was filtered through

Celite. The pentane was removed from the filtrate, leaving a pale yellow liquid, Me2Si(t-BuE4C5)(NH-t-Bu)

(11.4 g, 0.045 mol).

Part 3. MeSi(t-BuH 4 C 5 )(NH-t-Bu) (11.4 g, 0.045 mol) was diluted with slOO mL Et 2 O. MeLi (1.4 M, 70 mL, 0.098 mol) was slowly added. The mixture was stirred overnight. The ether was removed via vacuum to a trap maintained at -196 °C leaving a pale yellow solid, [Me2Si(t-BuH3C5)(N-t-Bu)]Li2 (11.9 g, 0.045 mol).

Part 4. [Me 2 Si(t-BuH 3 C 5 )(N-t-Bu)]Li 2 (3.39 g, 0.013 mol) was suspended in sl00 mL Et 2 O. ZrCl 4 (3.0 g, 0.013 mol) was slowly added. The mixture was stirred overnight. The ether was removed and pentane was added to precipitate LiCl. The mixture was filtered through Celite. The pentane solution was reduced in volume and the light brown solid was filtered off and washed several times with small amounts of pentane. The product of empirical formula Me2Si(t-BuH3C5)(N-t-Bu)]ZrCl2 (2.43 g, 0.0059 mol) was isolated.

Example D

Compound D:

The same procedure as in Example C for the preparation of compound C was followed with the exception of using HfCl4 in part 4. Thus, when [Me2Si(t-BuH3C5)(N-t-Bu)]Li2 (3.29 g, 0.012 mol) and HfCl4 (4.0 g, 0.012 mol) was used, the product with the empirical formula Me2Si(t-BuH3C5)(N-t-Bu )HfCl2 (1.86 g, 0.037 mol) was prepared.

Example E

Compound E:

Part 1. Me2SiCl2 (7.0 g, 0.054 mol) was diluted with a:100 mL ether. Me 3 SiC 5 H 4 Li (5.9 g, 0.041 mol) was slowly added. About 75 mL of THF was added and the mixture was stirred overnight. The solvent was removed via a vacuum to a cold trap maintained at -196° C. Pentane was added to precipitate the LiCl. The mixture was filtered through Celite. The solvent was removed from the filtrate to give Me2Si(Me3SiC5H4)Cl (8.1 g, 0.035 mol) as a pale yellow liquid.

Part 2. Me 2 Si(Me 3 SiC 5 H 4 )C 1 (3.96 g, 0.017 mol) was diluted with 5:50 mL ether. LiHN-t-Bu (1.36 g, 0.017 mol) was added slowly and the mixture was stirred overnight. The ether was removed via vacuum and pentane was added to precipitate the LiCl. The mixture was filtered through Celite and the pentane was removed from the filtrate. Me 2 Si(Me 3 SiC 5 H 4 )(NH-t-Bu) (3.7 g, 0.014 mol) was isolated as a pale yellow liquid.

Part 3. Me 2 Si(Me 3 SiC 5 H 4 )(NH-t-Bu) (3.7 g, 0.014 mol) was diluted with ether. MeLi (25 mL, 1.4M in ether, 0.035 mol) was slowly added. The mixture was stirred for 1.5 hours after the final addition of MeLi. The ether was removed via vacuum to give 4.6 g of a white solid formulated as Li 2 [Me 2 Si(Me 3 SiC 5 H 3 )-(N—t—Bu)]]* 34 Et 2 O and unreacted MeLi which was not removed from the solid.

Part 4. Li2[Me2Si(Me3SiC5H3)(N-t-Bu)]-3/4Et2O (1.44 g, 0.043

mol) was suspended in ∼50 mL of ether. ZrCl 4 (1.0 g, 0.0043 mol) was slowly added and the reaction mixture was stirred for a few hours. The solvent was removed via vacuum and pentane was added to precipitate LiCl. The mixture was filtered through Celite and the filtrate was reduced in volume. The flask was placed

in the freezer (—40°C) to maximize precipitation of the product. The solid was filtered off to give 0.273 of an off-white solid. The filtrate was again reduced in volume, the precipitate filtered off to obtain a further 0.345 g for a total amount of 0.62 g of the compound of empirical formula Me2Si-(Me3SiC5H3 ) (N-t-Bu)ZrCl2• The X-ray crystal structure of this product shows that the compound is dimeric by nature.

Example F

Compound F:

Part 1. Me4HC5SiMe2Cl was prepared as described in Example A

for the preparation of compound A, part 1.

Part 2. LiHNPh (4.6 g, 0.0462 mol) was dissolved in slOO ml THF.

Me4HC5SiMe2Cl (10.0 g, 0.0466 mol) was slowly added. The mixture was stirred overnight. The THF was removed via a vacuum. Petroleum ether and toluene were added to precipitate LiCl and the mixture was filtered through Celite. The solvent was removed leaving a dark yellow liquid, Me 2 Si(Me 4 HC 5 )(NHPh) (10.5 g, 0.0387 mol).

Part 3. Me 2 Si(Me 4 HC 5 )(NHPh) (10.5 g, 0.0387 mol) was diluted with s:60 mL ether. MeLi (1.4 M in ether, 56 mL, 0.0784 mol) was added slowly and the reaction mixture was stirred overnight. The resulting white solid, Li 2 [Me 2 Si(Me 4 C 5 )(NPh)" 3 /4Et 2 O (11.0 g) was filtered off and washed with ether.

Part 4. Li 2 [Me 2 Si(Me 4 C 5 )(NPh)-3/4Et 2 O (2.81 g, 0.083 mol) was suspended in s40 mL of ether. ZrCl 4 (1.92 g, 0.0082 mol) was slowly added and the mixture was stirred overnight. The ether was removed via vacuum and a mixture of petroleum ether and toluene was added to precipitate the LiCl. The mixture was filtered through Celite, the solvent mixture was removed via vacuum, and pentane was added. The mixture was placed in the freezer at -40"C to maximize precipitation of the product. The solid was then filtered off and washed with pentane. Me2Si(Me^s )(NPh)ZrCl2*Et20 was recovered as a pale yellow solid (1 .89 g).

Example G

Compound G:

The same procedure as that in Example F for the preparation of compound F was followed with the exception of using HfCl4 instead of ZrCl4 in part 4. Thus, when Li2[Me2Si(Me4C5)-(NPh)]'3/4Et20 (2.0 g , 0.0059 mol) and HfCl4 (1.89 g, 0.0059 mol) were used, then Me2Si (Me4C5 ) (NPh )Hf Cl2 • V?Et20 (.170

g) produced.

Example H

Compound H:

Part 1. MePhSiCl2 (14.9 g, 0.078 mol) was diluted with s250

ml of THF. Me4C5HLi (10.0 g, 0.078 mol) was slowly added as a solid. The reaction solution was stirred overnight. The solvent was removed via a vacuum to a cold trap maintained at -196° C. Petroleum ether was added to precipitate the LiCl. The mixture was filtered through Celite and the pentane was removed from the filtrate. MePhSi(Me4C5H)Cl (20.8 g, 0.075 mol) was isolated as a yellow viscous liquid.

Part 2. LiHN-t-Bu (4.28 g, 0.054 mol) was dissolved in ^100 mL THF. MePhSi(Me4C5H)Cl (15.0 g, 0.054 mol) was added dropwise. The yellow solution was stirred overnight. The solvent was removed via vacuum. Petroleum ether was added to precipitate LiCl. The mixture was filtered through Celite and the filtrate was evaporated. MePhSi(Me4C5H)(NH-t-Bu) (16.6 g, 0.053 mol) was recovered as an extremely viscous liquid.

Part 3. MePhSi(Me 4 C 5 H)(NH-t-Bu) (16.6 g, 0.053 mol) was diluted with slOO mL of ether. MeLi (76 mL, 0.106 mol, 1.4 M) was slowly added and the reaction mixture was stirred for 3 h. The ether was reduced in volume and the lithium salt was filtered off and washed with pentane to give 20.0 g of a pale yellow solid formulated as Li2[MePhSi(M<e>4C5)(N-t-Bu)]-3/4Et2<0. >

Part 4. Li2[MePhSi(Me4C5)(N-t-Bu)]-3/4Et2O (5.0 g, 0.0131 mol)

was suspended in £100 ml Et2O. ZrCl 4 (3.06 g, 0.0131 mol) was slowly added. The reaction mixture was stirred at room temperature for 1.5 hours and the color of the reaction mixture darkened slightly during this time. The solvent was removed via vacuum and a mixture of petroleum ether and toluene was added. The mixture was filtered through Celite to remove LiCl. The filtrate was evaporated to near dryness and filtered off. The off-white solid was washed with petroleum ether. The yield of product, MePhSi(Me 4 C 5 )-(N-t-Bu)ZrCl 2 , was 3.82 g (0.0081 mol).

Example I

Compound I:

Li2[MePhSi(Me4C5)(N-t-Bu)]*3/4Et20 was prepared as described in Example H for the preparation of compound H, Part 3.

Part 4. Li2[MePhSi(Me4C5)(N-t-Bu)]-3/4Et2O (5.00 g, 0.0131

mol) was suspended in sl00 ml Et 2 O. HfCl 4 (4.20 g, 0.0131 mol) was slowly added and the reaction mixture was stirred overnight. The solvent was removed via vacuum and petroleum ether was added to precipitate LiCl. The mixture was filtered through Celite. The filtrate was evaporated to near dryness and filtered off. The off-white solid was washed with petroleum ether. MePhSi(Me4C5)(N-t-Bu)HfCl2 was recovered (3.54 g, 0.0058 mol).

Example J

Compound J:

MePhSi(Me4C5)(N-t-Bu)HfMe2 was prepared by adding a stoichiometric amount of MeLi (1.4 M in ether) to MePhSi-(Me4C5)(N-t-Bu)HfCl2 suspended in ether. The white solid could be isolated in an almost quantitative yield.

Example K

Compound K:

Part 1. Me4C5SiMe2Cl was prepared as described in Example A

for the preparation of compound A, part 1.

Part 2. Me4C5SiMe2Cl (10.0 g, 0.047 mol) was diluted with s25

ml Et20. LiHNC 5 H 4 -p-n-Bu-1/10Et 2 O (7.57 g, 0.047 mol) was slowly added. The mixture was stirred for s3 hours. The solvent was removed via vacuum. Petroleum ether was added to precipitate LiCl, and the mixture was filtered through Celite. The solvent was removed leaving an orange viscous liquid, Me 2 Si (Me 4 C 5 H) (HNC£,H 4 -p-n-Bu) (12.7 g, 0.039 mol).

Part 3. Me2Si(Me4C5H((HNC6H4-p-n-Bu)) (12.7 g, 0.039 mol) was diluted with s50 mL Et2O. MeLi (1.4 M, 55 mL, 0.077 mol) was slowly added. The mixture was stirred for s3 h. The product was filtered off and washed with Et 2 O to give Li 2 [Me 2 Si(Me 4 C 5 )(NC 6 H 4 -p-n-Bu)[<*>3/4Et 2 O as a white solid (13.1 g, 0.033 mol).

Part 4. Li2[Me2Si(Me4C5)(NC6H4-p-n-Bu)]'3/4Et2O (3.45 g,

0.0087 mol) was suspended in 50 ml of Et 2 O. ZrCl 4 (2.0 g, 0.0086 mol) was slowly added and the mixture was stirred overnight. The ether was removed via vacuum and petroleum ether was added to precipitate LiCl. The mixture was filtered through Celite. The filtrate was evaporated to dryness to give a yellow solid

substance which was recrystallized from pentane and identified as Me2Si(Me4C5 ) (NC6H4-p-n-Bu)ZrCl2•2/3Et20 (4.2

g)<.>

Example L

Compound L:

Li 2 [Me 2 Si(Me 4 C 5 ) (NC 6 H 4 -p-n-Bu)]' 3 /4Et 2 O was prepared as described in Example K for the preparation of compound K, Part 3.

Part 4. Li2[Me2Si(Me4C5)(NC6H4-p-n-Bu)]'3/4Et2<0> (3.77 g,

0.0095 mol) was suspended in s50 ml of Et 2 O. HfCl 4 (3.0 g, 0.0094 mol) was slowly added as a solid and the mixture was stirred overnight. The ether was removed via vacuum and petroleum ether was added to precipitate LiCl. The mixture was filtered through Celite. Petroleum ether was removed via vacuum to give an off-white solid which was recrystallized from pentane. The product was identified as Me 2 Si(Me 4 C 5 )-(NC 6 E 4 -p-n-Bu)HfCl 2 (1.54 g, 0.0027 mol).

EXAMPLES 1-34 CONCERNING POLYMERIZATION

Example 1

Polymerization - Compound A

The polymerization was carried out in a 1 liter autoclave reactor equipped with a paddle stirrer, an external water jacket for temperature control, a regulated supply of dry nitrogen, ethylene, propylene, 1-butene and hexane, and a septum inlet for the introduction of other solvents, transition metal compound and alumoxane solutions . The reactor was dried and degassed thoroughly before use. A typical operation consisted of injecting 400 ml of toluene, 6 ml of 1.5 M MAO and 0.23 mg of compound A (0.2 ml of 11.5 mg in 10 ml of toluene solution) into the reactor. The reactor was then heated to 800°C and the ethylene (413.7 kPa) was introduced into the system. The polymerization reaction was limited to 30 minutes. The reaction was stopped by rapid cooling and venting of the system. The solvent was evaporated from the polymer using a stream of nitrogen. Polyethylene was recovered (9.2 g, MW = 257,200, MWD = 2.275).

Example 2

Polymerization - Compound A

The polymerization was carried out as in Example 1 with the following changes: 300 ml of toluene, 3 ml of 1.5 M MAO and 0.115 mg of compound A (0.1 ml of 11.5 mg in 10 ml of toluene solution). Polyethylene was recovered (3.8 g, MW = 359,800, MWD = 2.425).

Example 3

Polymerization - Compound A

The polymerization was carried out as in Example 2 using the identical concentrations. The difference consisted in carrying out the reaction at 40°C instead of 80°C as in the previous example. Polyethylene was recovered (2.4 g, MW = 635,000, MWD = 3.445).

Example 4

Polymerization - Compound A

The polymerization was carried out as in example 1 with the exception of using 300 ml of hexane instead of 400 ml of toluene. Polyethylene was recovered (5.4 g, MW = 212,600, MWD = 2.849).

Example 5

Polymerization - Compound A

Using the same reactor design and general method as in Example 1, 300 mL of toluene, 200 mL of propylene, 6.0 mL of 1.5 M MAO, and 0.46 mg of compound A (0.4 mL of 11 .5 mg in 10 ml toluene solution) introduced into the reactor. The reactor was heated to 80°C, the ethylene was added (413.7 kPa), and the reaction was allowed to proceed for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the solvent, 13.3 g of an ethylene-propylene copolymer was recovered (MW = 2027, 73.5 SCB/1000C by IR).

Example 6

Polymerization - Compound A

The polymerization was carried out as in Example 5, except for the following changes: 200 ml of toluene and 0.92 mg of compound A (0.8 ml of 11.5 mg in 10 ml of toluene solution). The reaction temperature was also reduced to 50°C. An ethylene-propylene copolymer was recovered (6.0 g, MW = 83,100, MWD = 2.370, 75.7 SCB/1000C by IR).

Example 7

Polymerization - Compound A

Using the same reactor design and general procedure as in Example 1, 150 ml of toluene, 100 ml of 1-butene, 6.0 ml of 1.5 M MAO and 2.3 mg of compound A (2.0 ml of 11 .5 mg in 10 ml toluene solution) added to the reactor. The reactor was heated at 50°C and the ethylene was introduced (448.2 kPa) and the reaction was allowed to proceed for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the toluene, 25.4 g of an ethylene-butene copolymer was recovered (MW = 184,500, MWD = 3.424, 23.5 SCB/1000C by <13>C NMR and 21.5 SCB/1000C by IR).

Example 8

Polymerization - Compound A

The polymerization was carried out as in Example 7, except for the following changes: 100 ml of toluene and 150 ml of 1-butene. An ethylene-butene copolymer was recovered (30.2 g, MW = 143,500, MWD = 3.097, 30.8 SCB/1000C by <13>C NMR and 26.5 SCB/1000C by

IR).

Example 9

Polymerization - Compound A

The polymerization was carried out as in Example 7, except for the following changes: 200 ml toluene and 8.0 ml 1.0 M MAO and 50 ml 1-butene. An ethylene-butene copolymer was recovered (24.9 g, MW = 163,200, MWD = 3.290, 23.3 SCB/1000C by <13>C NMR and 18.9 SCB/1000C by IR).

Example 10

Polymerization - Compound A

The polymerization was carried out as in Example 9, but with the exception of replacing 200 ml of toluene with 200 ml of hexane. An ethylene-butene copolymer was recovered (19.5 g, MW = 150,600, MWD = 3.510, 12.1 SCB/1000C by <13>C NMR and 12.7 SCB/1000C by

IR).

Example 11

Polymerization - Compound A

The polymerization was carried out as in Example 10, except for the following changes: 150 ml of hexane and 100 ml of 1-butene. An ethylene-butene copolymer was recovered (16.0 g, MW = 116,200, MWD = 3.158, 19.2 SCB/1000C by <13>C NMR and 19.4 SCB/1000C by

IR).

Example 12

Polymerization - Compound A

Using the same reactor design and general procedure as already described, 400 ml of toluene, 5.0 ml of 1.0 M MAO and 0.2 ml of a preactivated compound A solution (11.5 mg of compound A dissolved in 9.0 ml of toluene and 1.0 ml of 1.0 M MAO) added to the reactor. The reactor was heated to 80°C, the ethylene was introduced (413.7 kPa) and the reaction was allowed to proceed for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the solvent, 3.4 g of polyethylene was recovered (MW = 285,000, MWD = 2.808).

Example 13

Polymerization - Compound A

A polymerization was carried out as in Example 12, except for aging the preactivated Compound A solution for one day. Polyethylene was recovered (2.0 g, MW = 260,700, MWD = 2.738).

Example 14

Polymerises. ion - Compound A

Using the same reactor design and general procedure as already described, 400 ml of toluene, 0.25 ml of 1.0 M MAO, and 0.2 ml of a preactivated compound A solution (11.5 mg of compound A dissolved in 9.5 ml of toluene and 0.5 ml of 1.0 M MAO) added to the reactor. The reactor was heated to 80°C, the ethylene was introduced (413.7 kPa) and the reaction was allowed to proceed for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the solvent, 1.1 g of polyethylene was recovered (MW 479,600, MWD = 3.130).

Example 15

Polymerization - Compound A

Using the same reactor design and general procedure as already described, 400 ml of toluene and 2.0 ml of a preactivated compound A solution (11.5 mg of compound A dissolved in 9.5 ml of toluene and 0.5 ml of 1 .0 M MAO) added to the reactor. The reactor was heated to 80° C., the ethylene was introduced (413.7 kPa) and the reaction was allowed to proceed for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the solvent, 1.6 g of polyethylene was recovered (MW = 458,800, MWD = 2.037).

Example 16

Polymerization - Compound A

Using the general procedure already described, 400 ml of toluene, 5.0 ml of 1.0 M MAO, 0.23 mg of compound A (0.2 ml of 11.5 mg in 10 ml toluene solution) were added to the reactor . The reactor was heated to 80° C., the ethylene introduced (2758 kPa), and the reaction allowed to proceed for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the solvent, 19.4 g of polyethylene was recovered (MW = 343,700, MWD = 3.674).

Example 17

Polymerises. lon - Compound A

The polymerization was carried out in a stirred 100 ml stainless steel autoclave which was equipped for carrying out polymerizations at pressures up to 275.8 MPa and temperatures up to 300°C. The reactor was flushed with nitrogen and heated to 160°C. Compound A and alumoxane solutions were prepared in separate bottles by dissolving 26 mg of compound A in 100 mL of toluene. A stock solution was prepared by dissolving 26 mg of compound A in 100 ml of toluene. The compound A solution was prepared by diluting 0.5 ml of the stock solution with 5.0 ml of toluene. The alumoxane solution consisted of 2.0 ml of a 4% MAO solution added to 5.0 ml of toluene. The compound A solution was added to the alumoxane solution and then 0.43 ml of the mixed solutions were transferred by nitrogen pressure into a constant volume injection tube. The autoclave was pressurized with ethylene to 1784 bar and stirred at 1500 rpm. The mixed solutions were injected into the stirred reactor by means of excess pressure, at which time a temperature rise of 4°C was observed. The temperature was recorded continuously for 120 seconds and at this point the contents of the autoclave were rapidly vented into a receiver container. The reactor was washed with xylene to recover any additional polymer remaining therein. These washings were combined with the polymer released when the autoclave was vented to yield 0.7 g of polyethylene (MW = 245,500, MWD - 2.257).

Example 18

Polymerization - Compound B

Using the general procedure described in Example 1, 400 ml of toluene, 5.0 ml of 1.0 M MAO and 0.278 mg of compound B (0.2 ml of 13.9 mg in 10 ml toluene solution) were added to the reactor. The reactor was heated to 80°C and the ethylene (413.7 kPa) was introduced into the system. The polymerization reaction was limited to 10 minutes. The reaction was stopped by rapid cooling and venting of the system. The solvent was evaporated from the polymer using a stream of nitrogen. Polyethylene was recovered (9.6 g, MW = 241,200, MWD = 2.628).

Example 19

Polymerization - Compound C

Using the general methods described in Example 1, 300 ml of toluene, 4.0 ml of 1.0 M MAO and 0.46 mg of compound C (0.4 ml of 11.5 mg in 10 ml of toluene -solution) added to the reactor. The reactor was heated to 80°C and the ethylene (413.7 kPa) was introduced into the system. The polymerization reaction was limited to 30 minutes. The reaction was stopped by rapid cooling and venting of the system. The solvent was evaporated from the polymer with a stream of nitrogen. Polyethylene was recovered (1.7 g, MW = 278,400, MWD = 2.142).

Example 20

Polymerization - Compound D

Using the general method described in Example 1, 400 mL of toluene, 5.0 mL of 1.0 M MAO, and 0.278 mg of compound D (0.2 mL of 13.9 mg in 10 mL toluene solution) were added to the reactor . The reactor was heated to 80°C and the ethylene (413.7 kPa) was introduced into the system. The polymerization reaction was limited to 30 minutes. The reaction was stopped by rapid cooling and venting of the system. The solvent was evaporated from the polymer with a stream of nitrogen. Polyethylene was recovered (1.9 g, MW = 229,700, MWD = 2.618).

Example 21

Polymerization - Compound E

Using the general method described in Example 1, 300 ml of hexane, 9.0 ml of 1.0 M MAO and 0.24 mg of compound E (0.2 ml of 12.0 mg in 10 ml toluene solution) added to the reactor. The reactor was heated to 80°C and the ethylene (413.7 kPa) was introduced into the system. The polymerization reaction was limited to 30 minutes. The reaction was stopped by rapid cooling and venting of the system. The solvent was evaporated from the polymer with a stream of nitrogen. Polyethylene was recovered (2.2 g, MW = 258,200, MWD = 2.348).

Example 22

Polymerization - Compound E

The polymerization was carried out as in Example 1, with the following reactor contents: 200 ml of toluene, 100 ml of 1-butene, 9.0 ml of 1.0 M MAO and 2.4 mg of compound E (2.0 ml of 12.0 mg in 12 ml of toluene solution) at 50°C. The reactor was pressurized with ethylene (448.2 kPa) and the reaction was run for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the solvent, 1.8 g of an ethylene-butene copolymer was recovered (MW = 323,600, MWD = 2.462, 33.5 SCB/1000C by IR technique).

Example 23

Polymerization - Compound F

The polymerization was carried out as in Example 1, with the following reactor conditions: 400 ml of toluene, 5.0 ml of 1.0 M MAO, 0.242 mg of compound F (0.2 ml of 12.1 mg in 10 ml of toluene dissolved -ning), 80°C, 413.7 kPa ethylene, 30 minutes. The run yielded 5.3 g of polyethylene (MW = 319,900, MWD = 2.477).

Example 24

Polymerization - Compound F

The polymerization was carried out as in Example 1, with the following reactor conditions: 150 ml of toluene, 100 ml of 1-butene, 9.0 ml of 1.0 M MAO, 2.42 mg of compound F (2.0 ml of 12.1 mg in 10 ml toluene solution), 50°C, 448.2 kPa ethylene, 30 minutes. The run gave 3.5 g of an ethylene-butene copolymer (MW = 251,300, MWD = 3.341, 33.28 SCB/1000C by IR technique).

Example 25

Polymerization - Compound G

The polymerization was carried out as in example 1, with the following reactor conditions: 400 ml of toluene, 5.0 ml of 1.0 M MAO, 0.29 mg of compound G (0.2 ml of 14.5 mg in 10 ml of toluene solution ), 80°C, 413.7 kPa ethylene, 30 minutes. The run yielded 3.5 g of polyethylene (MW = 237,300, MWD = 2.549).

Example 26

Polymerization - Compound G

The polymerization was carried out as in Example 1, with the following reactor conditions: 150 ml of toluene, 100 ml of 1-butene, 7.0 ml of I, 0 M MAO, 2.9 mg of compound G (2.0 ml of 14.5 mg in 10 ml toluene solution), 50°C, 448.2 kPa ethylene, 30 minutes. The run gave 7.0 g of an ethylene-butene copolymer (MW 425,000, MWD = 2.816, 27.11 SCB/1000C by IR technique).

Example 27

Polymerization - Compound H

The polymerization was carried out as in example 1, with the following reactor conditions: 400 ml of toluene, 5.0 ml of 1.0 M MAO, 0.266 mg of compound H (0.2 ml of 13.3 mg in 10 ml of toluene solution), 80°C, 413.7 kPa ethylene, 30 minutes. The run gave II, 1 g of polyethylene (MW = 299,800, MWD = 2.569).

Example 28

Polymerization - Compound H

The polymerization was carried out as in Example 1, with the following reactor conditions: 150 ml of toluene, 100 ml of 1-butene, 7.0 ml of 1.0 M MAO, 2.66 mg of compound H (2.0 ml of 13.3 mg in 10 ml toluene solution), 50°C, 448.2 kPa ethylene, 30 minutes. The run gave 15.4 g of an ethylene-butene copolymer (MW = 286,600, MWD = 2.980, 45.44 SCB/1000C by IR technique).

Example 29

Polymer in sas. i on - Compound I

The polymerization was carried out as in Example 1, with the following reactor conditions: 400 ml of toluene, 5.0 ml of 1.0 M MAO and 0.34 mg of compound I (0.2 ml of 17.0 mg in 10 ml of toluene solution ) was added to the reactor. The reactor was heated to 80°C, the ethylene was introduced (413.7 kPa) and the reaction was allowed to proceed for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the solvent, 0.9 g of polyethylene was recovered (MW 377,000, MWD = 1.996).

Example 30

Polymerization - Compound J

The polymerization was carried out as in example 1, with the following reactor conditions: 400 ml toluene, 5.0 ml of 1.0 M MAO, 0.318 mg of compound J (0.2 ml of 15.9 mg in 10 ml toluene solution), 80°C, 413.7 kPa ethylene, 30 minutes. The run yielded 8.6 g of polyethylene (MW = 321,000, MWD = 2.803).

Example 31

Polymerization - Compound J

The polymerization was carried out as in Example 1, with the following reactor conditions: 150 ml of toluene, 100 ml of 1-butene, 7.0 ml of 1.0 M MAO, 3.18 mg of compound J (2.0 ml of 15.9 mg in 10 ml toluene solution), 50°C, 448.2 kPa ethylene, 30 minutes. The run gave 11.2 g of an ethylene-butene copolymer (MW = 224,800, MWD = 2.512, 49.57 SCB/1000C by IR technique, 55.4 SCB/1000C by NMR technique).

Example 32

Polymerization - Compound K

The polymerization was carried out as in example 1, with the following reactor conditions: 300 ml of toluene, 5.0 ml of 1.0 M MAO, 0.272 mg of compound K (0.2 ml of 13.6 mg in 10 ml of toluene solution), 80°C, 413.7 kPa ethylene, 30 minutes. The run yielded 26.6 g of polyethylene (MW = 187,300, MWD = 2.401).

Example 33

Polymer in sas. i on - Connection K

The polymerization was carried out as in Example 1, with the following reactor conditions: 150 ml of toluene, 100 ml of 1-butene, 7.0 ml of 1.0 M MAO, 2.72 mg of compound K (2.0 ml of 13.6 mg in 10 ml toluene solution), 50°C, 448.2 kPa ethylene, 30 minutes. The run gave 3.9 g of an ethylene-butene copolymer (MW = 207,600, MWD = 2.394, 33.89 SCB/1000C by IR technique).

Example 34

Polymerization - Compound L

The polymerization was carried out as in example 1, with the following reactor conditions: 400 ml toluene, 5.0 ml of 1.0 M MAO, 0.322 mg of compound L (0.2 ml of 16.1 mg in 10 ml toluene solution), 80°C, 413.7 kPa ethylene, 30 minutes. The run yielded 15.5 g of polyethylene (MW = 174,300, MWD = 2.193).

Example 35

Polymerization - Compound A

The polymerization was carried out as in Example 1, with the following reactor contents: 250 ml of toluene, 150 ml of 1-hexene, 7.0 ml of 1.0 M MAO and 2.3 mg of compound A (2.0 ml of 11.5 mg in 10 ml of toluene solution) at 50°C. The reactor was pressurized with ethylene (448.2 kPa) and the reaction allowed to proceed for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the solvent, 26.5 g of an ethylene-hexene copolymer was recovered (MW = 222,800, MWD = 3.373, 39.1 SCB/1000C by IR technique).

Example 36

Polymerization - Compound A

The polymerization was carried out as in Example 1, with the following reactor contents: 300 ml of toluene, 100 ml of 1-octene, 7.0 ml of 1.0 M MAO and 2.3 mg of compound A (2.0 ml of 11.5 mg in 10 ml of toluene solution) at 50°C. The reactor was pressurized with ethylene (448.2 kPa) and the reaction allowed to proceed for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the solvent, 19.7 g of an ethylene-octene copolymer was recovered (MW = 548,600, MWD = 3.007, 16.5 SCB/1000C by <13>C NMR technique).

Example 37

Polymerization - Compound A

The polymerization was carried out as in Example 1, with the following reactor contents: 300 ml of toluene, 100 ml of 4-methyl-1-pentene, 7.0 ml of 1.0 M MAO and 2.3 mg of compound A (2.0 ml of 11.5 mg in 10 ml toluene solution) at 50°C. The reactor was pressurized with ethylene (448.2 kPa) and the reaction allowed to proceed for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the solvent, 15.1 g of an ethylene-4-methyl-1-pentene copolymer was recovered (MW = 611,800, MWD = 1.683, 1.8 mol-# determined by <13>C-NMR).

Example 38

Polymerization - Compound A

The polymerization was carried out as in Example 1, with the following reactor contents: 300 ml of toluene, 100 ml of 2.2 M norbornene in toluene solution, 7.0 ml of 1.0 M MAO and 2.3 mg of compound A (2.0 ml of 11.5 mg in 10 ml toluene solution) at 50°C. The reactor was pressurized with ethylene (448.2 kPa) and the reaction allowed to proceed for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the solvent, 12.3 g of an ethylene-norbornene copolymer was recovered (MW = 812,600, MWD = 1.711, 0.3 mol-# determined by <13>C-NMR).

Example 39

Polymerization - Compound A

The polymerization was carried out as in Example 1, with the following reactor contents: 300 ml of toluene, 100 ml of cis-1,4-hexadiene, 7.0 ml of 1.0 M MAO and 2.3 mg of compound A (2.0 ml of 11.5 mg in 10 ml toluene solution) at 50°C. The reactor was pressurized with ethylene (448.2 kPa) and the reaction allowed to proceed for 30 minutes, followed by rapid cooling and venting of the system. After evaporation of the solvent, 13.6 g of an ethylene-cis-1,4-hexadiene copolymer was recovered (MW = 163,400, MWD = 2.388, 2.2 mol-* determined by <13>C-NMR).

Table 2 indicates the polymerization conditions used and the properties obtained in the product polymers as indicated in the above examples 1-34.

It appears that the need for the alumoxane component can be largely reduced by premixing the catalyst with the alumoxane before initiating the polymerization (see examples 12-15).

By properly selecting the (1) Group IVB transition metal component for use in the catalyst system; (2) the type and amount of alumoxane used; (3) polymerization diluent type and volume; and (4) reaction temperature; (5) reaction pressure, then the product polymer can be tailored to the desired weight average molecular weight value, while the molecular weight distribution is still kept at a value below approx. 4.0.

The preferred polymerization diluents in the present application are aromatic diluents such as toluene, or alkanes such as hexane.

The resins obtained by the polymerization can be used for the production of a number of different products including films and fibres.

Claims (3)

1. Use of a metallocene compound (I) of the general formula: where: M is Zr, Hf or Ti; (C5H5_y_x_Rx) is a cyclopentadienyl ring substituted with from 0 to 5 R groups, "x" is 0, 1, 2, 3, 4 or 5 denoting the degree of substitution, and each R is independently a radical selected from C ]— C2o_ny(irocarbyl radicals, substituted C-l~ C2o-hydrocarbyl radicals where one or more hydrogen atoms are replaced by a halogen atom, C] —C2o-hydrocarbyl-substituted metalloid radicals where the metalloid is selected from group IVA in the periodic table and halogen radicals; (JR'z -l-y) is a heteroatom ligand where J is an element with a coordination number of 3 from group VA or an element with a coordination number of 2 from group VIA of the periodic table, each R' is independently a radical selected from Cj — C20 hydrocarbyl radicals, substituted Cy-C20-nydrocarDyl~ radicals where one or more hydrogen atoms are replaced by a halogen atom, and "z" is the coordination number of the element J; each Q or Q' is independently halogen, hydride or a substituted or unsubstituted C1-C20 hydrocarbyl, alkoxide, aryloxide, amide, arylamide, phosphide or arylphosphide provided that when Q or Q' is a hydrocarbyl such Q or Q' is different from C5H5_y_xRx or both Q and Q' together are an alkylidene or cyclometalated hydrocarbyl and M' has the same meaning as M; "y" is 0 or 1 when w is greater than 0; y is 1 when w is 0, when "y" is 1 then B is a covalent bridging group containing a Group IVA or VA element, and L is a neutral Lewis base where "w" denotes a number from 0 to 3, in olefin polymerization of ethylene and a monomer selected from a C3-C20 α-olefin or a C5-C20<d>ioolefin, except : (i) polymerization of ethylene and vinyl aromatic monomer, and (ii) when compound (i) is (N-t-butylamino )(dimethyl )(n5-2,3,4,5-tetramethylcyclopentadienyl)silane zirconium dichloride, polymerization of ethylene and 1-hexene or 4-methyl-1-pentene. 2. Use according to claim 1 in a liquid phase polymerization. 3. Use according to claim 2 in a liquid phase polymerization where ethylene is exposed to a reaction zone at a pressure from 0.131 to 344,750 kPa abs. and a reaction temperature from -100 to 300°C.