WO1997042228A1 - Supported catalyst composition and process for the polymerization of olefin monomers - Google Patents

Abstract

A catalyst system comprising a carrier material, at least one transition metal complex and optionally at least one co-catalyst. The transition metal complex consists of a reduced transition metal (e.g. titanium), chosen from groups 4-6 of the Periodic Table of the Elements, with a multidentate monoanionic ligand and with two monoanionic ligands. The invention also relates to a process for producing polymers using the catalyst system, and to the obtained polymer products.

Description

SUPPORTED CATALYST COMPOSITION AND PROCESS

FOR THE POLYMERIZATION OF OLEFIN MONOMERS

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to supported catalyst systems and to the polymerization of α-olefin monomers using such supported catalyst systems. In particular the invention relates to catalyst systems comprising a carrier material, at least one transition metal complex and one or more co-catalysts and to a process for producing polymers by polymerization of α- olefins using said supported catalyst systems, and to the obtained polymer products and their use.

2. Background Information

EP-A-548,257 describes a supported catalyst system comprising an inert support, a monocyclopentadienyl compound of a "Group 4" transition metal and an aluminoxane. Drawbacks of the supported catalyst systems according to EP-A-548,257 (the complete disclosure of which is incorporated herein by reference) are that with these catalysts only products with a low molecular weight can be produced and that these catalyst systems have a low activity. Commercial polymerization of α- olefin monomers with these catalyst systems is not feasible.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the aforementioned problems associated with the related art as well as to address the need expressed above. In accordance with this object, the present invention provides new supported catalyst systems which are particularly suitable for the production of α- olefin (co-)polymers having a high molecular weight, and which present high activity. The capability of attaining higher than standard molecular weights with the incorporation of a given amount of comonomers under a given set of polymerizing conditions is referred to as the superior "copolymer molecular weight capability" of the present polymerization process.

In accordance with the principles of the present invention, this object is attained by providing a catalyst composition and a process for the polymerization of at least one α-olefin in the presence of the present catalyst composition.

The catalyst composition includes at least one complex comprising a reduced valency transition metal (M) selected from groups 4-6 of the Periodic Table of Elements, a multidentate monoanionic ligand (X), two monoanionic ligands (L), and, optionally, additional ligands (K). More specifically, the complex of the catalyst composition of the present invention is represented by the following formula (I):

X (I)

I

M - L₂

I K_m

wherein the symbols have the following meanings: M a reduced transition metal selected from group 4, 5 or 6 of the Periodic Table of Elements?

X a multidentate monoanionic ligand represented by the formula: (Ar-R_t-),Y(-R_t-DR '_n)_q; Y a cyclopentadienyl, amido (-NR'-), or phosphido group (-PR'-), which is bonded to the reduced transition metal M; R at least one member selected from the group consisting of (i) a connecting group between the Y group and the DR'_n group and (ii) a connecting group between the Y group and the Ar group, wherein when the ligand X contains more than one R group, the R groups can be identical to or different from each other; D an electron-donating hetero atom selected from group 15 or 16 of the Periodic Table of Elements; R' a substituent selected from the group consisting of a hydrogen, hydrocarbon radical and hetero atom-containing moiety, except that R' cannot be hydrogen when R' is directly bonded to the electron-donating hetero atom D, wherein when the multidentate monoanionic ligand X contains more than one substituent R', the substituents R' can be identical or different from each other; Ar an electron-donating aryl group;

L a monoanionic ligand bonded to the reduced transition metal M, wherein the monoanionic ligand L is not a ligand comprising a cyclopentadienyl, amido (-NR'-), or phosphido (-PR'-) group, and wherein the monoanionic ligands L can be identical or different from each other; K a neutral or anionic ligand bonded to the reduced transition metal M, wherein when the transition metal complex contains more than one ligand K, the ligands K can be identical or different from each other ; m is the number of K ligands, wherein when the K ligand is an anionic ligand m is 0 for M³⁺, m is 1 for M⁴⁺, and m is 2 for M^s+, and when K is a neutral ligand m increases by one for each neutral K ligand; n the number of the R' groups bonded to the electron-donating hetero atom D, wherein when D is selected from group 15 of the Periodic Table of Elements n is 2 , and when D is selected from group 16 of the Periodic Table of Elements n is 1; q,s q and s are the number of (-R_t-DR'_n) groups and (Ar-R_t-) groups bonded to group Y, respectively, wherein q + s is an integer not less than 1; and t the number of R groups connecting each of (i) the Y and Ar groups and (ii) the Y and DR'_n groups, wherein t is selected independently as 0 or 1.

These and other objects, features, and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate the present invention. In such drawings:

FIG. 1 is a schematic view of a cationic active site of a trivalent catalyst complex in accordance with an embodiment of the present invention; and

FIG. 2 is a schematic view of a neutral active site of a trivalent catalyst complex of a dianionic ligand of a conventional catalyst complex according to WO-A-93/19104.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various components (groups) of the transition metal complex are discussed below in more detail.

(a) The Transition Metal (M) The transition metal in the complex is selected from groups 4-6 of the Periodic Table of Elements. As referred to herein, all references to the Periodic Table of Elements mean the version set forth in the new IUPAC notation found on the inside of the cover of the Handbook of Chemistry and Physics, 70th edition, 1989/1990, the complete disclosure of which is incorporated herein by reference. More preferably, the transition metal is selected from group 4 of the Periodic Table of Elements, and most preferably is titanium (Ti) .

The transition metal is present in reduced form in the complex, which means that the transition metal is in a reduced oxidation state. As referred to herein, "reduced oxidation state" means an oxidation state which is greater than zero but lower than the highest possible oxidation state of the metal (for example, the reduced oxidation state is at most M³⁺ for a transition metal of group 4, at most M⁴⁺ for a transition metal of group 5 and at most M⁵⁺ for a transition metal of group 6).

(b) The X Ligand

The X ligand is a multidentate monoanionic ligand represented by the formula: (Ar-R_t-)_BY(-R_t-DR '_n)_q.

As referred to herein, a multidentate monoanionic ligand is bonded with a covalent bond to the reduced transition metal (M) at one site (the anionic site, Y) and is bonded either (i) with a coordinate bond to the transition metal at one other site (bidentate) or (ii) with a plurality of coordinate bonds at several other sites (tridentate, tetradentate, etc.). Such coordinate bonding can take place, for example, via the D heteroatom or Ar group(s). Examples of tridentate monoanionic ligands include, without limitation, Y-R_t-DR '_n_ι.-R_t-DR '_n and Y(-R-DR'_n)₂. It is noted, however, that heteroatom(s) or aryl substituent(s) can be present on the Y group without coordinately bonding to the reduced transition metal M, so long as at least one coordinate bond is formed between an electron-donating group D or an electron donating Ar group and the reduced transition metal M. R represents a connecting or bridging group between the DR'_n and Y, and/or between the electron¬ donating aryl (Ar) group and Y. Since R is optional, "t" can be zero. The R group is discussed below in paragraph (d) in more detail.

(c) The Y Group The Y group of the multidentate monoanionic ligand (X) is preferably a cyclopentadienyl, amido

(-NR'-), or phosphido (-PR'-) group.

Most preferably, the Y group is a cyclopentadienyl ligand (Cp group). As referred to herein, the term cyclopentadienyl group encompasses substituted cyclopentadienyl groups such as indenyl, fluorenyl, and benzoindenyl groups, and other polycyclic aromatics containing at least one 5-member dienyl ring, so long as at least one of the substituents of the Cp group is an R_t-DR'_n group or

R_t-Ar group that replaces one of the hydrogens bonded to the five-member ring of the Cp group via an exocyclic substitution.

Examples of a multidentate monoanionic ligand with a Cp group as the Y group (or ligand) include the following (with the (-R_t-DR'_n) or (Ar-R_t-) substituent on the ring) : R ' R '

R-DR R-Ar

The Y group can also be a hetero cyclopentadienyl group. As referred to herein, a hetero cyclopentadienyl group means a hetero ligand derived from a cyclopentadienyl group, but in which at least one of the atoms defining the five-member ring structure of the cyclopentadienyl is replaced with a hetero atom via an endocyclic substitution. The hetero Cp group also includes at least one R_t-DR'_n group or R_t-Ar group that replaces one of the hydrogens bonded to the five-member ring of the Cp group via an exocyclic substitution. As with the Cp group, as referred to herein the hetero Cp group encompasses indenyl, fluorenyl, and benzoindenyl groups, and other polycyclic aromatics containing at least one 5-member dienyl ring, so long as at least one of the substituents of the hetero Cp group is an R_t-DR'_n group or R_t-Ar group that replaces one of the hydrogens bonded to the five-member ring of the hetero Cp group via an exocyclic substitution.

The hetero atom can be selected from group 14, 15 or 16 of the Periodic Table of Elements. If there is more than one hetero atom present in the five- member ring, these hetero atoms can be either the same or different from each other. More preferably, the hetero atom(s) is/are selected from group 15, and still more preferably the hetero atom(s) selected is/are phosphorus.

By way of illustration and without limitation, representative hetero ligands of the X group that can be practiced in accordance with the present invention are hetero cyclopentadienyl groups having the following structures, in which the hetero cyclopentadienyl contains one phosphorus atom (i.e., the hetero atom) substituted in the five-member ring:

R R-DR

It is noted that, generally, the transition metal group M is bonded to the Cp group via an r_\ ⁵ bond.

The other R' exocyclic substituents (shown in formula (III)) on the ring of the hetero Cp group can be of the same type as those present on the Cp group, as represented in formula (II). As in formula (II), at least one of the exocyclic substituents on the five- member ring of the hetero cyclopentadienyl group of formula (III) is the R_t-DR'_n group or the R_t-Ar group. The numeration of the substitution sites of the indenyl group is in general and in the present description based on the IUPAC Nomenclature of Organic Chemistry 1979, rule A 21.1. The numeration of the substituent sites for indene is shown below. This numeration is analogous for an indenyl group: Indene

(IV)

The Y group can also be an amido (-NR'-) group or a phosphido (-PR'-) group. In these alternative embodiments, the Y group contains nitrogen (N) or phosphorus (P) and is bonded covalently to the transition metal M as well as to the (optional) R group of the (-R_t-DR'_n) or (Ar-R_t-) substituent.

(d) The R Group The R group is optional, such that it can be absent from the X group. Where the R group is absent, the DR'_n or Ar group is bonded directly to the Y group (that is, the DR'_n or Ar group is bonded directly to the Cp, amido, or phosphido group). The presence or absence of an R group between each of the DR'_n groups and/or Ar groups is independent.

Where at least one of the R groups is present, each of the R group constitutes the connecting bond between, on the one hand the Y group, and on the other hand the DR'_n group or the Ar group. The presence and size of the R group determines the accessibility of the transition metal M relative to the DR'_n or Ar group, which gives the desired intramolecular coordination. If the R group (or bridge) is too short or absent, the donor may not coordinate well due to ring tension. The R groups are each selected independently, and can generally be, for example, a hydrocarbon group with 1-20 carbon atoms (e.g., alkylidene, arylidene, aryl alkylidene, etc.). Specific examples of such R groups include, without limitation, methylene, ethylene, propylene, butylene, phenylene, whether or not with a substituted side chain. Preferably, the R group has the following structure:

(-CR'₂-)_P (IV) where p = 1-4. The R' groups of formula (IV) can each be selected independently, and can be the same as the R' groups defined below in paragraph (g).

In addition to carbon, the main chain of the R group can also contain silicon or germanium. Examples of such R groups are: dialkyl silylene (-SiR'₂-), dialkyl germylene (-GeR'₂-), tetra-alkyl silylene (-SiR'₂-SiR'₂-) , or tetraalkyl silaethylene (-SiR'₂CR'₂- ). The alkyl groups in such a group preferably have 1-4 carbon atoms and more preferably are a methyl or ethyl group.

(e) The DR '_n Group

This donor group consists of an electron- donating hetero atom D, selected from group 15 or 16 of the Periodic Table of Elements, and one or more substituents R' bonded to D. The number (n) of R' groups is determined by the nature of the hetero atom D, insofar as n being 2 if D is selected from group 15 and n being 1 if D is selected from group 16. The R' substituents bonded to D can each be selected independently, and can be the same as the R' groups defined below in paragraph (g) , with the exception that the R' substituent bonded to D cannot be hydrogen. The hetero atom D is preferably selected from the group consisting of nitrogen (N) , oxygen (0), phosphorus (P) and sulphur (S); more preferably, the hetero atom is nitrogen (N) . Preferably, the R' group is an alkyl, more preferably an n-alkyl group having 1- 20 carbon atoms, and most preferably an n-alkyl having 1-8 carbon atoms. It is further possible for two R' groups in the DR'_n group to be connected with each other to form a ring-shaped structure (so that the DR'_n group can be, for example, a pyrrolidinyl group). The DR'_n group can form coordinate bonds with the transition metal M. ( f ) The Ar Group

The electron-donating group (or donor) selected can also be an aryl group (C₆R'_S), such as phenyl, tolyl, xylyl, mesityl, cumenyl, tetramethyl phenyl, pentamethyl phenyl, a polycyclic group such as triphenylmethane, etc. The electron-donating group D of formula (I) cannot, however, be a substituted Cp group, such as an indenyl, benzoindenyl, or fluorenyl group.

The coordination of this Ar group in relation to the transition metal M can vary from h_. ¹ to h.⁶.

(g) The R' Group

The R' groups may each separately be hydrogen or a hydrocarbon radical with 1-20 carbon atoms (e.g. alkyl, aryl, aryl alkyl and the like as shown in Table

1).

Examples of alkyl groups are methyl, ethyl, propyl, butyl, hexyl and decyl. Examples of aryl groups are phenyl, mesityl, tolyl and cumenyl. Examples of aryl alkyl groups are benzyl, pentamethylbenzyl, xylyl, styryl and trityl. Examples of other R' groups are halides, such as chloride, bromide, fluoride and iodide, methoxy, ethoxy and phenoxy. Also, two adjacent hydrocarbon radicals of the Y group can be connected with each other to define a ring system; therefore the Y group can be an indenyl, a fluorenyl or a benzoindenyl group. The indenyl, fluorenyl, and/or benzoindenyl can contain one or more R' groups as substituents. R' can also be a substituent which instead of or in addition to carbon and/or hydrogen can comprise one or more hetero atoms of groups 14-16 of the Periodic Table of Elements. Thus, a substituent can be, for example, a Si-containing group, such as Si(CH₃)₃. (h) The L Group

The transition metal complex contains two monoanionic ligands L bonded to the transition metal M. Examples of the L group ligands, which can be identical or different, include, without limitation, the following: a hydrogen atom; a halogen atom; an alkyl, aryl or aryl alkyl group; an alkoxy or aryloxy group; a group comprising a hetero atom selected from group 15 or 16 of the Periodic Table of Elements, including, by way of example, (i) a sulphur compound, such as sulphite, sulphate, thiol, sulphonate, and thioalkyl, and (ii) a phosphorus compound, such as phosphite, and phosphate. The two L groups can also be connected with each other to form a dianionic bidentate ring system. These and other ligands can be tested for their suitability by means of simple experiments by one skilled in the art.

Preferably, L is a halide and/or an alkyl or aryl group; more preferably, L is a Cl group and/or a C_x-C_t alkyl or a benzyl group. The L group, however, cannot be a Cp, amido, or phosphido group. In other words, L cannot be one of the Y groups.

(i) The K Ligand The K ligand is a neutral or anionic group bonded to the transition metal M. The K group is a neutral or anionic ligand bonded to M. When K is a neutral ligand K may be absent, but when K is monoanionic, the following holds for K_m: m = 0 for M³⁺ m = 1 for M⁴⁺ m = 2 for M^s+

On the other hand, neutral K ligands, which by definition are not anionic, are not subject to the same rule. Therefore, for each neutral K ligand, the value of m (i.e., the number of total K ligands) is one higher than the value stated above for a complex having all monoanionic K ligands.

The K ligand can be a ligand as described above for the L group or a Cp group (-C_SR'₅), an amido group (-NR'₂) or a phosphido group (-PR'₂). The K group can also be a neutral ligand such as an ether, an amine, a phosphine, a thioether, among others.

If two K groups are present, the two K groups can be connected with each other via an R group to form a bidentate ring system.

As can also be seen from formula (I), the X group of the complex contains a Y group to which are linked one or more donor groups (the Ar group(s) and/or

DR'_n group(s)) via, optionally, an R group. The number of donor groups linked to the Y group is at least one and at most the number of substitution sites present on a Y group.

With reference, by way of example, to the structure according to formula (II), at least one substitution site on a Cp group is made by an R_t-Ar group or by an R_t-DR'_n group (in which case q + s = 1).

If all the R' groups in formula (II) were R_t-Ar groups,

R_t-DR'_n groups, or any combination thereof, the value of

(q + s) would be 5. One preferred embodiment of the catalyst composition according to the present invention comprises a transition metal complex in which a bidentate/monoanionic ligand is present and in which the reduced transition metal has been selected from group 4 of the Periodic Table of Elements and has an oxidation state of +3.

In this case, the catalyst composition according to the invention comprises a transition metal complex represented by formula (V) : X

I

M ( I I I ) - L₂ , ( V )

I K_m

where the symbols have the same meaning as described above for formula (I) and where M(III) is a transition metal selected from group 4 of the Periodic Table of Elements and is in oxidation state 3+.

Such a transition metal complex has no anionic K ligands (for an anionic K, m = 0 in case of M³⁺) .

It should be pointed out that in WO-A- 93/19104, transition metal complexes are described in which a group 4 transition metal in a reduced oxidation state (3+) is present. The complexes described in WO-A- 93/19104 have the general formula:

Cp_a(ZY)_bML_c (VI)

The Y group in this formula (VI) is a hetero atom, such as phosphorus, oxygen, sulfur, or nitrogen bonded covalently to the transition metal M (see p. 2 of WO-A- 93/19104). This means that the Cp_a(ZY)_b group is of a dianionic nature, and has the anionic charges residing formerly on the Cp and Y groups. Accordingly, the Cp_a(ZY)_b group of formula (VI) contains two covalent bonds: the first being between the 5-member ring of the Cp group and the transition metal M, and the second being between the Y group and the transition metal. By contrast, the X group in the complex according to the present invention is of a monoanionic nature, such that a covalent bond is present between the Y group (e.g., the Cp group) and transition metal, and a coordinate bond can be present between the transition metal M and one or more of the (Ar-R_t-) and (-R_t-DR'_n) groups. This changes the nature of the transition metal complex and consequently the nature of the catalyst that is active in the polymerization. As referred to herein, a coordinate bond is a bond (e.g., H₃N-BH₃) which when broken, yields either (i) two species without net charge and without unpaired electrons (e.g., H₃N: and BH₃) or (ii) two species with net charge and with unpaired electrons (e.g., H₃N- ⁺ and BH₃-^~). On the other hand, as referred to herein, a covalent bond is a bond (e.g., CH₃-CH₃) which when broken yields either (i) two species without net charge and with unpaired electrons (e.g., CH₃- and CH₃- ) or (ii) two species with net charges and without unpaired electrons (e.g. , CH₃ ⁺ and CH₃:^~). A discussion of coordinate and covalent bonding is set forth in Haaland et al. (Angew. Chem Int. Ed. Eng. Vol. 28, 1989, p. 992), the complete disclosure of which is incorporated herein by reference.

The following explanation is proposed, although it is noted that the present invention is in no way limited to this theory. Referring now more particularly to FIG. 2, the transition metal complexes described in WO-A- 93/19104 are ionic after interaction with the co¬ catalyst. However, the transition metal complex according to WO-A-93/19104 that is active in the polymerization contains an overall neutral charge (on the basis of the assumption that the polymerizing transition metal complex comprises, a M(III) transition metal, one dianionic ligand and one growing monoanionic polymer chain (POL)). By contrast, as shown in FIG. 1, the polymerization active transition metal complex of the catalyst composition according to the present invention is of a cationic nature (on the basis of the assumption that the polymerizing transition metal complex - based on the formula (V) structure - comprises, a M(III) transition metal, one monoanionic bidentate ligand and one growing monoanionic polymer chain (POL ) ) .

Transition metal complexes in which the transition metal is in a reduced oxidation state, but have the following structure:

Cp - M(III) - L₂ (VII)

are generally not active in co-polymerization reactions. It is precisely the presence, in the transition metal complex of the present invention, of the DR'_n or Ar group (the donor), optionally bonded to the Y group by means of the R group, that gives a stable transition metal complex suitable for polymerization. Such an intramolecular donor is to be preferred over an external (intermolecular) donor on account of the fact that the former shows a stronger and more stable coordination with the transition metal complex. It will be appreciated that the catalyst system may also be formed in situ if the components thereof are added directly to the polymerization reactor system and a solvent or diluent, including liquid monomer, is used in said polymerization reactor. The catalyst composition of the present invention also contains a co-catalyst. For example, the co-catalyst can be an organometallic compound. The metal of the organometallic compound can be selected from group 1, 2, 12 or 13 of the Periodic Table of Elements. Suitable metals include, for example and without limitation, sodium, lithium, zinc, magnesium, and aluminum, with aluminum being preferred. At least one hydrocarbon radical is bonded directly to the metal to provide a carbon-metal bond. The hydrocarbon group used in such compounds preferably contains 1-30, more preferably 1-10 carbon atoms. Examples of suitable compounds include, without limitation, amyl sodium, butyl lithium, diethyl zinc, butyl magnesium chloride, and dibutyl magnesium. Preference is given to organoaluminium compounds, including, for example and without limitation, the following: trialkyl aluminum compounds, such as triethyl aluminum and tri-isobutyl aluminum; alkyl aluminum hydrides, such as di-isobutyl aluminum hydride; alkylalkoxy organoaluminium compounds; and halogen-containing organoaluminium compounds, such as diethyl aluminum chloride, diisobutyl aluminum chloride, and ethyl aluminum sesquichloride. Preferably, linear or cyclic aluminoxanes are selected as the organoaluminium compound. In addition or as an alternative to the organometallic compounds as the co-catalyst, the catalyst composition of the present invention can include a compound which contains or yields in a reaction with the transition metal complex of the present invention a non-coordinating or poorly coordinating anion. Such compounds have been described for instance in EP-A-426,637, the complete disclosure of which is incorporated herein by reference. Such an anion is bonded sufficiently unstably such that it is replaced by an unsaturated monomer during the co¬ polymerization. Such compounds are also mentioned in EP-A-277,003 and EP-A-277,004, the complete disclosures of which are incorporated herein by reference. Such a compound preferably contains a triaryl borane or a tetraaryl borate or an aluminum equivalent thereof. Examples of suitable co-catalyst compounds include, without limitation, the following: dimethyl anilinium tetrakis (pentafluorophenyl) borate [C₆H_SN(CH₃)₂H]⁺ [B(C₆F₅)₄]-; - dimethyl anilinium bis (7,8-dicarbaundecaborate)- cobaltate (III); - tri (n-butyl)ammonium tetraphenyl borate;

- triphenylcarbenium tetrakis (pentafluorophenyl) borate; dimethylanilinium tetraphenyl borate; - tris(pentafluorophenyl ) borane; and

- tetrakis(pentafluorophenyl) borate.

If the above-mentioned non-coordinating or poorly coordinating anion is used, it is preferable for the transition metal complex to be alkylated (that is, the L group is an alkyl group). As described for instance in EP-A-500, 944 , the complete disclosure of which is incorporated herein by reference, the reaction product of a halogenated transition metal complex and an organometallic compound, such as for instance triethyl aluminum (TEA), can also be used.

The molar ratio of the co-catalyst relative to the transition metal complex, in case an organometallic compound is selected as the co-catalyst, usually is in a range of from about 1:1 to about 10,000:1, and preferably is in a range of from about 1:1 to about 2,500:1. If a compound containing or yielding a non-coordinating or poorly coordinating anion is selected as co-catalyst, the molar ratio usually is in a range of from about 1:100 to about 1,000:1, and preferably is in a range of from about 1:2 to about 250:1.

As a person skilled in the art would be aware, the transition metal complex as well as the co¬ catalyst can be present in the catalyst composition as a single component or as a mixture of several components. For instance, a mixture may be desired where there is a need to influence the molecular properties of the polymer, such as molecular weight and in particular molecular weight distribution. The inert support component may be any finely divided solid porous support, including, but not limited to, MgCl₂, Zeolites, mineral clays, inorganic oxides such as talc, silica, alumina, silica-alumina, inorganic hydroxides, phosphates, sulphates, etc., or resinous support materials such as polyolefins, including polystyrene, or mixtures thereof. These carriers may be used as such or modified, for example by silanes and/or aluminum alkyls and/or aluminoxane compounds, etc.

The transition metal complex or the co- catalyst is supported on a carrier. It is also possible that both the transition metal complex and the co-catalyst are supported on a carrier. The carrier material for the transition metal complex and for the co-catalyst can be the same material or a different material. It is also possible to support the transition metal complex and the co-catalyst on the same carrier. The supported catalyst systems of the invention can be prepared as separate compounds, which can be used as such in polymerization reactions or the supported catalyst systems can be formed in situ just before a polymerization reaction starts.

Supported catalyst systems of the invention may be prepared by several methods. The transition metal complex of group 4 - 6 and the aluminoxane component can be mixed together before the addition of the support material, or the mixture can be added to the support material. The mixture may be prepared in conventional solution in a normally liquid alkane or aromatic solvent. Such solvents include, but are not limited to, linear or branched alkanes such as pentane, hexane, heptane, pentamethyl heptane, isobutane and isopentane, and aromatic solvents such as toluene. The solvent is preferably also suitable for use as a polymerization diluent for the liquid phase polymerization of an olefin monomer. Alternatively, the aluminoxanes can be placed on the support material followed by the addition of the transition metal complex or conversely, the transition metal complex may be applied to the support material followed by the addition of the aluminoxanes. The aluminoxanes can be used as commercially supplied, or may be generated in situ on the solid support, for example, by the addition of a trialkylaluminum compound to a hydrated support, for example by the addition of trimethylaluminum to a wetted or undehydrated silica. The supported catalyst may be prepolymerized. In addition third components can be added in any stage of the preparation of the supported catalyst. Third components can be defined as compounds containing Lewis acidic or basic functionalities exemplified but not limited to compounds such as N.N-dimethylaniline, tetraethoxysilane, phenyltriethoxysilane, bis-tert- butylhydroxy toluene (BHT) and the like.

Transition metal components wherein the metal is titanium have been found to impart beneficial properties to a catalyst system, which is unexpected in view of what is known about the properties of cyclopentadienyl titanium compounds which are cocatalyzed by aluminoxanes. Whereas titanocenes in their soluble form are generally unstable in the presence of aluminum alkyls, the metal components of this invention generally exhibit greater stability (i.e. longer catalyst lifetime), resulting in higher catalyst activity rates (expressed as Kg polymer produced per g of Ti per hour). A higher α-olefin comonomer incorporation at a high molecular weight are also surprisingly advantageous features of the catalyst systems according to the invention ("comonomer molecular weight capability").

In summary, the supported catalyst systems of the invention comprise a reduced transition metal complex, a carrier and optionally one or more organo- aluminum compounds and/or a compound which contains or yields in a reaction with the transition metal complex a non-coordinating or poorly coordinating anion.

In the process according to the invention the polymerization of α-olefin monomers is carried out using a supported catalyst system as described above. In particular the α-olefin monomer(s) is/are suitably chosen from the group comprising ethene, propene, butene, pentene, heptene, hexene, octene and styrene (substituted or non-substituted). Mixtures of these compounds may also be used. More preferably, ethene and/or propene is used as α-olefin. The use of such olefins results in the formation of (semi)crystalline polyethene homo- and copolymers, of high as well as of low density (HDPE, LDPE, LLDPE, etc.), and polypropene, homo- and copolymers (PP and EMPP (Elastomer modified polypropylene)). The monomers needed for such products and the processes to be used are known to those of ordinary skill in the art. The process according to the invention is also suitable for the preparation of amorphous or rubber-like copolymers based on ethene and another α- olefin. Propene is preferably used as the other α- olefin, so that EPM rubber is formed. It is also possible to use other dienes than ethene and other α- olefins, so that a so-called EADM rubber (ethylene-α- olefin-diene terpolymer) is formed, in particular EPDM (ethene propene diene rubber).

Polymerization of the α-olefin monomer(s) can be effected in a known manner, in the gas phase as well as in a liquid reaction medium. Both solution and suspension polymerization are suitable for use in a liquid reaction medium. The supported catalyst systems according to the invention are used mainly in gas phase and slurry processes. The quantity of transition metal to be used generally is such that its concentration in the dispersion agent is between about 10^~θ and 10^~3 mol/1, preferably between about IO^-7 and 10"* mol/1. The invention will hereafter be described with reference to polymerizations of α-olefins known per se, which are representative of the polymerization referred to in the present description. For the preparation of other polymers on the basis of α-olefin monomers, the reader is expressly referred to the multitude of publications on this subject. The process of the present invention can be conducted as a gas phase polymerization (e.g. in a fluidized bed reactor), as suspension/slurry polymerization, as a solid phase powder polymerization or as a so called bulk polymerization process, with excess olefinic monomer used as the reaction medium. Dispersion agents may suitably be used for the polymerization, which may be chosen from (but are not limited to) saturated, straight or branched aliphatic hydrocarbons, such as butanes, pentanes, hexanes, heptanes, pentamethyl heptane or mineral oil fractions such as light or regular petrol, naphtha, kerosene or gas oil. Fluorinated hydrocarbons or similar liquids are also suitable for this purpose. Aromatic hydrocarbons, for instance benzene and toluene, can be used, but because of cost and safety considerations, it is preferable not to use such solvents for production on a tecnnical scale. In polymerization processes on a technical scale, it is preferred to use low-priced aliphatic hydrocarbons or mixtures thereof as solvents, as marketed by the petrochemical industry. If an aliphatic hydrocarbon is used as solvent, the solvent may yet contain minor quantities of aromatic hydrocarbon, for instance toluene. Thus, if for instance methyl aluminoxane (MAO) is used as co- catalyst, toluene can be used as solvent for the MAO in order to supply the MAO in dissolved form to the polymerization reactor. Drying or purification of the solvents is desirable if such solvents are used; this can be accomplished using known procedures by persons of ordinary skill in the art. In the process of the invention the catalyst and the co-catalyst are used in a catalytically effective amount, i.e. any amount that succesfully results in the formation of polymer. Such amounts may be readily determined by routine experimentation by the skilled artisan.

It will be appreciated that the catalyst system may also be formed in situ if the components thereof are added directly to the polymerization reactor system and a solvent or diluent, including liquid monomer, is used in the polymerization reactor. If a solution or bulk polymerization is to be used it is preferably carried out at temperatures well above the melting point of the polymer to be produced, typically, but not limited to, temperatures between 120°C and 260°C.

According to a preferred embodiment of the invention, the process is carried out under suspension or gasphase polymerization conditions which typically take place at temperatures well below the melting temperature of the polymer to be produced, typically, but not limited to, temperatures below 105°C.

The polymer resulting from the polymerization can be worked up by methods known to the skilled artisan. In general the catalyst is de-activated at some point during the processing of the polymer. The de-activation is also effected in a manner known per se, e.g. by means of water or an alcohol. Removal of the catalyst residues can usually be omitted because the quantity of catalyst in the polymer, in particular the content of halogen and transition metal, is very low when the catalyst system according to the invention is used.

Polymerization can be effected at atmospheric pressure, at sub-atmospheric pressure, or at elevated pressure of up to 500 MPa, continuously or discontinuously. Preferably, the polymerization is performed at pressures between 0.01 and 500 MPa, most preferably between 0.01 and 10 MPa, in particular between 5 and 30 bar (= 0.5-3 MPa). Higher pressures up to about 500 MPa can be applied. In such a high- pressure process the process according to the present invention can also be used with good results. Slurry and solution polymerization normally take place at lower pressures, preferably below 20 MPa.

The polymerization can also be performed in several steps, in series as well as in parallel. If required, the catalyst composition, temperature, hydrogen concentration, pressure, residence time, etc. may be varied from step to step. In this way it is also possible to obtain products with a wide molecular weight distribution.

The invention also relates to a polyolefin polymer which can be obtained by means of the polymerization process according to the invention.

The invention will now be illustrated by means of the following non-restrictive examples.

All tests in which organometallic compounds were involved were carried out in an inert nitrogen atmosphere, using standard Schlenk equipment. A method for synthesis of (dimethylaminoethyl)-tetramethyl cyclopentadienyl was published by P. Jutzi et al., Synthesis 1993, 684 (the complete disclosure of which is incorporated herein by reference).

TiCl₃, the esters used and the lithium reagents, 2-bromo-2-butene and 1-chlorocyclohexene were obtained from Aldrich Chemical Company. TiCl₃.3THF was obtained by heating TiCl₃ for 24 hours in THF (tetrahydrofurane) with reflux. In the following, ^'Me' means "methyl', ^* iPr ' means Asopropyl, 'Bu' means "butyl', 'iBu' means 'isobutyl', 'tertBu' means 'tertiary butyl', 'Ind' means 'indenyl', 'Flu' means 'fluorenyl', 'Ph' means 'phenyl', Cp = cyclopentadienyl, Cp* = tetramethylcyclopentadienyl, with substituents other than Me attached to it additionally. Pressures mentioned are absolute pressures. SEC-DV = size exclusion chromatography. MWD = molecular weight distribution, is defined as Mw/Mn. Mz , Mn and Mw are molecular weights determined by universal calibration of SEC-DV.

Mz^*, Mw^* and Mn^* are molecular weights determined by conventional calibration of SEC-DV.

Example I Preparation of a supported catalyst system comprising (dimethylaminoethyl) tetramethyleyelopentadienyl-titanium(III)dichloride (C₅Me₄((CH₂)₂NMe₂)TiCl₂).

a. Preparation of 4-hvdroxy-4-(dimethylamino-ethyl )- 3, 5-dimethyl-2 ,5-heptadiene

2-bromo-2-butene (108 g; 0.800 mol) was added to 10.0 g of lithium (1.43 mol) in diethyl ether (300 ml) in about 30 minutes with reflux. After stirring overnight (17 hours), ethyl-3-(N,N- dimethylamino)propionate (52.0 g; 0.359 mol) was added to the reaction mixture in about 15 minutes. After stirring for 30 minutes at room temperature 200 ml of water was added dropwise. After separation the water phase was extracted two times with 50 ml of CH₂C1₂. The organic phase was reduced by evaporation and the residue was distilled at reduced pressure. The yield was 51.0 g (67%).

b. Preparation of (dimethylaminoethyl)tetramethyl- cyclopentadiene

The compound (21.1 g; 0.10 mol) prepared as described under a) was added in a single portion to p- toluenesulphonic acid.H₂0 (28.5 g; 0.15 mol), dissolved in 200 ml of diethyl ether. After stirring for 30 minutes at room temperature the reaction mixture was poured out in a solution of 50 g of Na₂CO₃.10H₂O in 250 ml of water. After separation the water phase was extracted two times with 100 ml of diethyl ether. The combined ether layer was dried (Na₂S0₄), filtered and evaporated. Then the residue was distilled at reduced pressure. The yield was 11.6 g (60%).

c. Preparation of (dimethylaminoethyl)tetramethyl¬ cyclopentadienyltitaniumfIII)dichloride 1.0 equivalent of n-BuLi (1.43 ml; 1.6 M) was added (after cooling to -60°C) to a solution of the C₅Me₄H(CH₂)₂NMe₂ of b) (0.442 g; 2.29 mmol) in THF (50 ml), after which the cooling bath was removed. After warming to room temperature the solution was cooled to -100°C and then TiCl₃.3THF (0.85 g; 2.3 mmol) was added in a single portion. After stirring for 2 hours at room temperature the THF was removed at reduced pressure. After addition of special boiling point gasoline the complex (a green solid) was purified by repeated washing of the solid, followed by filtration and backdistillation of the solvent. It was also possible to obtain the pure complex through sublimation.

d. preparation of the supported catalyst system To 1.453 g of Si0₂ (obtained from Grace -

Davison under code W952), dried for 4 hours at 400°C under a dry nitrogen flow and 10ml of dry toluene were added. 16 ml of methylaluminoxane (MAO from Witco, 30% in tolune) were then added over a period of 10 minutes, with constant mixing at a temperature of 300 K. Subsequently the sample was dried under vacuum for 2 hours under constant mixing. 25 ml of an alkane mixture (C6 fraction) were then added and the suspension was mixed for a further 12 hours at 300 K. Then a suspension of the organo metal complex of example Ic was added under continuous mixing. After drying the obtained mixture the catalyst system was shown to contain 27,9 wt % of Al and a Al/Ti ratio of 328.

Example II Preparation of an ethene/octene copolymer with bimodal MWD, using a supported catalyst system comprising (dimethylaminoethyl) tetramethylcyclopentadienyl-titanium(III)dichloride (C₅Me₄( (CH₂)₂NMe₂)TiCl₂).

General procedure :

Octene was distilled and dried over a moleculare sieve of type 13X.

600 ml of an alkane mixture were brought as solvent under dry nitrogen in a stainless steel reactor having a content of 1.5 liter. For ethene-octene polymerisations 10 grammes of dry octene were then added to the reactor. The reactor was then heated under constant mixing to the required temperature under an absolute pressure of ethene of 8 bar (800 kPa).

In a catalyst dosing vessel having a content of 100 ml, 25 ml of an alkane mixture was dosed as dispersion medium. The desired amount of catalyst was then introduced. The catalyst slurry thus obtained was subsequently dosed to the reactor. The polymerisation reaction was thus started and carried out under isotherm conditions. The ethene pressure was maintained constant at 8 bar absolute. The ethene addition was interrupted after t minutes and the reaction mixture was collected and quenched with methanol. Irganox 1076 (TM) was then added to the product as anti-oxidant to stabilise the polymer. The polymer was dried under vacuum at 70°C for 24 hours. Using this general procedure 18 g octene were introduced into the reactor. Then 20 micromoles (on the basis of Ti) of the supported catalyst system of example Id were added to the reactor. The polymerisation took place at an ethene pressure of 8 bar at 80 °C. The obtained polymer (28050 kg/mol Ti*hour) was analysed by SEC-DV and showed a bimodal molecular weight distribution (MWD = 15). The weight- averaged molecular weight (Mw) was 400 kg/mol at an octene content of 9.9 mol % (as shown by ¹H-NMR).

Example III Preparation of an ethene/octene copolymer with unimodal MWD, using a supported catalyst system comprising (dimethylaminoethyl) tetramethylcyclopentadienyl-titanium(III)dichloride

(C_sMe₄( (CH₂)₂NMe₂)TiCl₂) .

Applying the procedure described in example II hereabove, using however 10 micromols (on the basis of Ti) of catalyst and a polymerisation temperature of 120 °C, a polymer was obtained having a unimodal MWD distribution with MWD = 7.3.

Example IV

Preparation of a very high molecular weight type polyethene using a supported catalyst system comprising (dimethylaminoethyl)tetramethyl- cyclopentadienyl-titanium(III)dichloride ( C₅Me₄ ( ( CH₂ ) ₂NMe₂ ) T i Cl ₂ ) .

a. Preparation of the supported catalyst system.

2.646 g MAO/Si0₂ (from Witco, based on PQ MS3040 Si0₂, 21.7 weight% Al) were weighed in a Schlenk vessel. 20 ml of a dry alkane mixture (C6-fraction) were added at 300 K, followed by the addition of a solution of the metal complex of example Ic. This mixture was dried under vacuum at 300 K. A powder was obtained having an Al/Ti ratio of 178. 1.0417 g of this powder were weighed in a Schlenk vessel and washed with toluene at 300 K and dried for 20 minutes under vacuum at room temperature.

b. Polymerisation

5 micromol (on Ti basis) of the supported catalyst system prepared in example IVa were used to carry out a polymerisation using the procedure of example II, at a temperature of 80 °C. The ethene pressure was kept at 600 kPa. The obtained homopolymer of ethene was analysed by SEC-DV, using conventional calibration. The polyethylene had a very high molecular weight, had a bimodal MWD of 10.4 and a MW^* of 1.4 * IO⁶ g/mol.

Example V

Preparation of a ethene-styrene copolymer using a supported catalyst system comprising (dimethylaminoethyl)tetramethyl-cyclopentadienyl- titanium(III)dichloride (C_sMe₄( (CH₂)₂NMe₂)TiCl₂) .

Following the procedure described in example II a copolymerisation of ethene and styrene was carried out using the same supported catalyst. Styrene was distilled under vacuum from CaH₂. 45 g of styrene were added to the reactor. 20 micromols (based on Ti) of the catalyst were then introduced in the reactor. The polymerisation was carried out at a temperature of 80°C, at an ethene pressure of 8 bar. The obtained polymer (1450 kg/mol Ti * hour) was analysed by SEC-DV. The molecular weight Mw showed to be 490.000 g/mol with a styrene content of 3,1 mol% (as shown by Η-NMR) .

Example VI

Preparation of a high molecular weight type polymer using a supported catalyst system comprising Cp^*(EtNMe₂)TiCl₂.LiCl.

a. Preparation of the metal complex

Using the procedure described in example la- c, Cp^*(EtNMe₂)TiCl₂.LiCl. was obtained by recovering the green solid complex without removing all LiCl.

b. Preparation of the supported catalyst system and homopolymerisation of ethene. 20 ml of dry toluene were added to 3.9 g of

MA0/Si0₂ (from Witco) as described in example IV, and subsequently 4,4 ml. of a solution of the catalyst complex of example Via in toluene, containing 2,5 IO^"5 mol/ml, were added at room temperature. The mixture was then evacuated for 45 min under constant mixing. A slurry was obtained from the resulting dry supported catalyst.

Polymerisation was carried out under the conditions described in example IV, during 10 minutes at 95°C. The polymer particles produced were stabilised with Irganox 1076 and dried under vacuum for 24 hours at 70°C. The polymer was analysed by SEC-DV using, conventional calibration. The Mn^* was determined to be 105 kg/mol, Mw^* 700 kg/mol and Mz^* 1780 kg/mol. No fouling of the reactor occurred. Example VII

Synthesis of the Cp(iPr)₃) (EtNMe₂)TiCl₂ catalyst.

Reaction of cyclopentadiene with isopropyl bromide. Aqueous KOH (50%; 1950g, ca. 31.5 mol in 2.483 1 water) and Adogen 464 (31.5g) were placed in a 3 1 three-neck flask fitted with a condenser, mechanical stirrer, heating mantle, thermometer, and an inlet adapter. Freshly cracked cyclopen-tadiene (55.3 g, 0.79 mol) and isopropyl bromide (364 g, 2.94 mol) were added and stirring was begun. The mixture turned brown and became warm (50°C). The mixture was stirred vigorously over night, after which the upper layer containing the product was removed. Water was added to this layer and the product was extracted with hexane. The combined hexane layer was washed once with water and once with brine, and after drying (MgS0₄) the solvent was evaporated, leaving a yellow-brown oil. GC and GC-MS analysis showed the product mixture to consist of diisopropyl-cyclopentadien (iPr₂-Cp, 40%) and triisopropylcyclopentadien (iPr₃-Cp, 60%). (iPr₂-Cp and iPr₃-Cp were isolated by distillation at reduced (20 mmHg) pressure. Yield depending on distillation accuracy (approx. 0.2 mol iPr₂-Cp (25%) and 0.3 mol iPr₃-Cp (40%)).

Reaction of lithium 1,2,4-triisopropylcvclopentadienyl with dimethylaminoethyl chloride. In a dry 500 ml flask under dry nitrogen, containing a magnetic stirrer, a solution of 62.5 ml of n-butyllithium (1.6 M in n-hexane; lOOmmol) was added to a solution of 19.2 g (100 mmol) of iPr₃-Cp in 250 ml of THF at-60°C. The solution was allowed to warm to room temperature (in approx. 1 hour) after which the solution was stirred over night. After cooling to - 60°C, dimethylaminoethyl chloride (11.3g, 105 mmol, freed from HCl by the method of Rees W.S. Jr. & Dippel K.A. in OPPI BRIEFS vol 24, No 5, 1992) was added via a dropping funnel in 5 minutes. The solution was allowed to warm to room temperature after which it was stirred over night. The progress of the reaction was monitored by GC. After addition of water (and pet-ether), the organic layer was separated, dried and evaporated under reduced pressure. Next to starting material iPr₃-Cp (30%), 5 isomers of the product

(dimethylaminoethyl )triisopropylcyclopentadien (LH; 70%) are visible in GC . Two isomers are geminal (together 30%). Removal of the geminal isomers was feasible by precipitation of the potassium salt of the iPr₃-Cp anion and filtration and washing with pet-ether (3x). Overall yield (relative to iPr₃-Cp) was 30 mmol (30%) .

Reaction sequence to r 1,2 ,4-triisopropyl-3- (dimethylaminoethyl)-eyelopentadenyl 1titanium (III) dichloride.

Solid TiCl₃3THF (18.53g, 50.0 mmol) was added to a solution of the potassium salt of iPr₃-Cp in 160 ml of THF at-60°C at once, after which the solution was allowed to warm to room temperature. The color changed from blue to green. After all the TiCl₃.3THF had disappeared the reaction mixture was cooled again to - 60°C. After warming to room temperature again, the solution was stirred for an additional 30 minutes after which the THF was removed at reduced pressure.

Preparation of the supported catalyst system and polymerisation using the supported catalyst.

A supported catalyst was prepared according to the method described in example VI. The Ti-component was, however, the metal complex of example Vila. The Al/Ti ratio in the supported catalyst was determined using neutron activation analysis and atomic absorption spectromety to be 285.

Under the conditions described in example IV octene and ethene were copolymerised at 80 C. The copolymer formed was stabilized and dried, and characterised using SEC- DV. The molecular weight distribution (MWD) of the product was determined using universal calibration and appeared to be 6.8. The Mw of the polymer was determined using the same method to have the high value of 1.2*10⁶ g/mol. The Mz appeared to be 5.6*10⁶ g/mol.

Example VIII Preparation of an ethene/octene copolymer using a supported catalyst system comprising Cp( iPr )₃(EtNMe₂)TiCl₂ at a relatively high temperature.

An ethene/octene copolymerisation was carried out as described in example VII but now at 121 C. 9.1 kg copolymer were produced per g Ti per 5 minutes. The

Mw was determined as described in example VII and was shown to amount 180 kg/mol.

Mz appeared to be 450 kg/mol and the MWD was found to be 2.5.

Example IX

Preparation of an ethene/octene copolymer using a supported catalyst system comprising Cp(iPr )₃(EtNMe₂)TiCl₂ in the presence of a scavenger.

An ethene/octene copolymerisation was carried out as described in example VIII except for the fact that triethylaluminium (TEA) was introduced into the reactor before the supported catalyst was. The amount of the scavenger TEA used was such that the Al/Tl-ratio was 40.

The copolymer yield was 8.4 kg/gTi*5min, the MWD was

2.2, the Mw was 81 kg/mol and the Mz was 180 kg/mol.

Example X

Preparation of an UHMWPE polymer using a supported catalyst system comprising Cp(2- pentyl)₂(EtNMe₂)TiCl₂.

a. Preparation of the metal complex

Under a nitrogen atmosphere, a solution of n- butyllithium in hexane (24.0 ml; 1.6 mol/L; 38 mmol) was added dropwise to a cooled (0°C) solution of di-(2- pentyl)cyclopentadiene (7.82 g; 38.0 mmol) in dry tetrahydrofuran (125 ml) in a 250 ml three-necked round-bottomed flask provided with a magnetic stirrer and a dropping funnel. After 24 hours' stirring at room temperature, 2-(dimethylaminoethyl) tosylate (38.0 mmol) prepared in situ was added. After 18 hours' stirring the conversion was found to be 92%, and water (100 ml) was carefully added dropwise to the reaction mixture and the tetrahydrofuran was then distilled off. The crude product was extracted with ether and the combined organic phase was then dried (sodium sulphate) and evaporated to dryness. The residue was purified on a silica gel column, which resulted in 8.2 g of (dimethylaminoethyl)- di (2-pentyl )cyclopentadiene.

In a Schlenk vessel, 1.60 g (5.77 mmol) of (dimethylaminoethyl)di (2-pentyl)cyclopentadiene were dissolved in 40 mL of diethyl ether and the solution was then cooled to -60°C. Then 3.6 mL of n-butyllithium (1.6M in hexane; 5.77 mmol) were added dropwise. The reaction mixture was slowly brought to room temperature, followed by stirring for 2 hours. In a second Schlenk vessel 40 mL of tetrahydrofuran were added to 2.14 g of Ti (III)C1₃.3THF (5.77 mmol). Both Schlenk vessels were cooled to -60°C and the organolithium compound was then added to the Ti(III)Cl₃ suspension. The reaction mixture was then stirred for 18 hours at room temperature, after which the solvent was evaporated. To the residue 50 mL of petroleum ether were added, which was subsequently evaporated to dryness. 1.60 g of a green solid remained containing 1- (dimethylaminoethyl)-2,4-di(2-pentyl)cyclopentadienyl- titanium(III) dichloride.

b. Preparation of the supported catalyst system

A supported Ti catalyst was synthesized as described in example IV. 1.6 g MAO/Si0₂ (Witco, see example IV) was slurried in 12 ml dry toluene. 4.6*10^"5 moles of the transition metal complex of example Xa was added under stirring at 300 K. The resulting slurry was dried under vacuum for 2 hours at 300 K. A fine, free- flowing powder was obtained.

c. Polymerisation

1*10^"5 moles (on Ti-basis) of the catalyst of example Xb were used for a polymerisation experiment under the conditions described in example IV. The ethene pressure was 600 kPa, the polymerisation temperature 96 C. The polymer formed was drained from the reactor, quenched with methanol, stabilized with irganox 1076 (TM) , dried at 70°C for 24 hours and studied with SEC-DV using conventional calibration. The MWD of the polymer was 6.4, Mw^* was found to be l.l*10^fi g/mol and Mz^* appeared to be 2.8*10⁶ g/mol.

Example XI

Preparation of an ethene/octene copolymer using a supported catalyst system comprising Cp(2- pentyl)₂(EtNMe₂)TiCl₂. A polymerisation reaction was carried out as described in example X with the difference that now 5 ml octene was introduced into the reactor before the start of the polymerisation reaction. The polymer formed was studied as described in example X.

Mw^* was 430 kg/mol, Mz^* was found to be 1.2*10⁶ g/mol and the MWD of the copolymer was found to be 4.6.

Example XII Preparation of a polyethene with high molecular weight using a supported catalyst system comprising two metal complexes.

In the same way as was described in example X a supported catalyst was synthesized. The difference was that the catalyst consisted of two Ti-complexes supported on the same support.

To 3.6 g MA0/Si0₂ (see example X), 27 ml toluene was added under stirring at 300 K, followed by 4*10^~5 mol of the metal complex of example Xa and 6*10^"5 mol of the metal complex of example Via. The slurry that was formed was dried while stirring at 300 K during 90 minutes, under vacuum.

A polymerisation was performed with the catalyst that was synthesized. The polymerisation conditions were as in example X. The polymer formed had a broadened MWD of

8.2, an Mw^* of 840 kg/mol and a Mz^* of 2.5*10⁶ g/mol.

Example XIII Preparation of an ethene/octene copolymer of high octene content using a supported catalyst system comprising two metal complexes.

A polymerisation was performed under the conditions described in example X but with the catalyst that was synthesized in example XII. The difference with the reaction conditions described in example X was that 25 ml octene were introduced in the reactor before the start of the polymerisation reaction. The polymer that was formed during the polymerisation reaction was treated as described in example X and appeared to be a copolymer with an octene content in the polymer chains of 19 wt.% as determined by using ^XH-NMR. Despite this high octene content the Mz^* appeared to be as high as 1.3*10⁶ g/mol, Mw^* was 560 kg/mol and the MWD appeared to be 4.8.

Example XIV Preparation of an ethene homopolymer using a catalyst system comprising (dimethylaminoethyl) tetramethylcyclopentadienyl-titanium(III)dichloride (C_sMe₄( (CH₂)₂NMe₂)TiCl₂) supported on Si0₂.

A supported catalyst was prepared in the following way.

40 ml dry toluene were added to 1.04 g Si0₂ (Aerosil

380 (TM) , dried 4 hours at 400°C under dry nitrogen).

Subsequently 18.5 ml of a 1.5 M solution of MAO in toluene (Witco) were added over a period of 10 minutes under contstant stirring at room temperature. The mixture was evacuated overnight under constant mixing. In a next step 12.05 ml dry toluene were added to 1.026 g of MAO/Si0₂ as obtained above. Subsequently 2.6 ml of a 0.025 mol/1 solution of the reduced transition metal complex of example Ic were added at room temperature. The mixture was evacuated for 60 minutes under continuous mixing.

A slurry was obtained from the resulting dry supported catalyst.

With this supported catalyst an ethene homopolymerisation was performed as described in example X during 10 minutes at 96°C. The polymer was studied by SEC-DV using universal calibration. Mn was found to amount 230 kg/mol, Mw was found to amount 1120 kg/mol and Mz was found to amount 2500 kg/mol.

Example XV

Preparation of an ethene homopolymer using a catalyst system comprising (dimethylaminoethyl) tetramethylcyclopentadienyl-titanium(III)diehloride (C_sMe₄( (CH₂)₂NMe₂)TiCl₂) supported on MgCl₂.

A supported catalyst was prepared in the following way. 20 ml dry toluene were added to 3.05 g dried MgCl₂

(average particle size 30 micrometer), and subsequently 30 ml of a 1.5 mol/1 solution of methylaluminoxane (MAO, Wico) in toluene were added over a period of 15 minutes under continuous stirring at room temperature. The mixture was evacuated for 2 hours under constand mixing. 50 ml of an alkane mixture (C₆-fraction) were added and the suspension was mixed well. To 20 ml of this mixture 6.3 ml of a 0.01 M solution of the reduced transition metal complex of example Ic in toluene were added at room temperature. The mixture was evacuated under constant mixing. 50 ml of an alkane (C₆-fraction) were added to the solids thus obtained, and the suspension was washed with a large surplus of a C₆- fraction and was finally evacuated under constant stirring.

With a slurry of the powder that was thus obtained a polymerisation experiment was performed as described in example X. The polymer formed was studied by SEC-DV. The Mn was determined with universal calibration to amount 175 kg/mol, Mw appeared to be 970 kg/mol and Mz appeared to be 2250 kg/mol.

Example XVI

Preparation of an ethene homopolymer using a supported catalyst system comprising Cp(iPr )₃(EtNMe₂)TiCl₂.

A supported catalyst was prepared in the following way. 10 ml dry toluene were added to 1.45 g MA0/Si0₂ (Witco) and subsequently 4.1 ml of a 0.01 M solution of the reduced transition metal complex of example VII were added at room temperature. The mixture was then evacuated under continuous stirring at room temperature. 50 ml of dry toluene were added and the suspension was mixed. The suspension was washed with a surplus of dry toluene and evacuated under constant mixing.

A slurry in an alkane medium (C₆-fraction) was obtained from the resulting free flowing powder and a polymerisation experiment was performed following the procedure described in example X. The resulting polymer particles, which showed an excellent morphology and no rector fouling whatsoever, were studied by SEC-DV using universal calibration in order to determine molecular weight characteristics. The Mn of the polymer was found to be 210 kg/mol, Mw was 800 kg/mol and Mz was found to be 1800 kg/mol.

Example XVII

a. Synthesis of supported catalyst

184 mg MA0/Si02 were weighed in a 100 mL Schlenk vessel (MAO on PQ MS3040 silica, obtained from Witco GmbH, 21.7 wt% Al). 10 mL of a 1*10-2 M solution of C₅Me₄(CH₂)₂NMe₂)TiMe2 in toluene were added to the solid MA0/Si0₂ while stirring at room temperature. The catalyst was prepared according to example I(A-C). The catalyst was methylated with MeLi in diethylether . In the next step 20 mL of a 10-2M solution of N,N-dimethylanilinium tetra-kis(pentafluorophenyl)- borate were added to the slurry. The resulting slurry was dried under vacuum at roomtemperature, while stirring, until a dry, free-flowing powder was obtained. 50 mL of a dry hexane fraction were added to the free-flowing powder to obtain a catalyst slurry with [Ti] = 2*10-6 mol/mL.

b. Polymerisation with supported catalyst

In a catalyst dosing vessel 10-5 mol of the supported catalyst (Ti-based, thus Al/Ti = 15, B/Ti =

2) were slurried in 100 mL pentamethylheptane during 1 minute.

The slurry was introduced into a IL reactor, that had been filled with 0,75 L PMH at 95 C and kept at a constant ethylene pressure of 6 bar. The activity was immediate and remained constant in time.

Catalyst activity amounted 1535 gPE/g catalyst.hr. The resulting polymer was analysed using GPC. Mw was 960 kg/mol, Mn was 260 kg.mol, MWD = 3.7.

Example XVIII al. Preparation of bis(trimethylsilyl)cvclopentadiene A roundbottom flask with a content of 5 L, supplied with a peddle stirrer, thermometer, dripping funnel, and N₂ inlet was filled with 550 mL dry THF. 66 g. (1.0 mol) freshly cracked cyclopentadiene was added thereto, whereafter the reaction mixture was cooled to

-40 °C. During cooling the slow dropwise addition of 1 equivalent (625 mL/1.6 M) butyl lithium was started. The complete addition was finished after 45 min..

Thereafter the reaction mixture was stirred for 1.5 hours, whereafter in 15 min. 130 mL (1.0 mol) trimethylsilylchloride was added. With GC it was demonstrated that the conversion to mono-substituted Cp was complete after 1 hour. In 30 min. 1 equivalent (625 mL/1.6 M) butyl lithium was added at -40 °C. After 1.5 hour stirring 130 mL (1.0 mol) trimethylsilylchloride was added at -40 °C. After 12 hours of stirring it was demonstrated with GC that 10% mono- and 90% bistrimethylsilyl-Cp were present in the reaction mixture.

The reaction mixture was distilled at 4.4 mbar and 61 °C. After distillation 138 g. bistrimethylsilyl-Cp was obtained. The product was characterised with GC, GC-MS, ¹³C- en ^XH-NMR.

a2. Preparation of bis(trimethylsilyl)-N,N- dimethylaminoethyl cyclopentadiene

A roundbottom flask with a content of 250 mL supplied with a thermometer, a dripping funnel and N₂- inlet was filled with 80 mL dry THF. 15 g. (71.43 mmol) bistrimethylsilyl-Cp was added thereto, whereafter was cooled to -30 °C. Thereafter 1 equivalent (44.6 mL/1.6 M) butyllithium was added in 10 min. The reaction mixture was allowed to warm up to room temperature. A roundbottom flask with a content of 500 mL supplied with a thermometer, a dripping funnel and N₂-inlet was filled with 100 mL dry THF and 6.4 g. (71.9 mmol) tosylchloride. After addition a white suspension was formed, which disappeared at 0 °C during cooling till - 30 °C. Thereafter the reaction mixture with the bistrimethylsilyl-Cp was added. The total reaction mixture was stirred for 12 hours. With GC it was demonstrated that 94.4% bis(trimethylsilyl )-N,N- dimethylaminoethyl-Cp was present in the reaction mixture. The product was distilled at 0.6 mbar and 103 °C. After distillation 10.5 g (>95% pure) bis(trimethylsilyl)-N,N-dimethylaminoethyl-Cp was obtained. The product was characterised with GC, GC-MS, ¹³C- en ^-NMR.

b. Synthesis of supported catalyst

2.2 g MA0/Si02 were weighed in a 100 mL Schlenk vessel (MAO on silica, Grace XPO 2409, obtained from Grace GmbH, 14.3 wt% Al) . 20.1 mL of a dry hexane mixture were added. 0.4 mL of a 0.1 M solution of ( (Cp(SiMe₃)₂(EtNMe₂) )TiCl₂ in a dry hexane mixture were added to the MA0/Si0₂ slurry while stirring at room temperature. The resulting slurry, with [Ti] = 2*10^"6 mol/mL, was used to polymerise ethylene.

c. Polymerisation with supported catalyst

In a catalyst dosing vessel 10-5 mol of the supported catalyst (Ti-based, Al/Ti = 284) were slurried in 100 mL pentamethylheptane during 1 minute. The slurry was introduced into a IL reactor, that had been filled with 0,75 L PMH and 4*10^"3 mol trioctylaluminium (TOA) at 40 C and kept at a constant ethylene pressure of 6 bar. The activity was immediate. The reactor contents were heated from 40 to 80 C in 8 minutes, starting immediately after the catalyst had been introduced.

Catalyst activity amounted 183 gPE/g catalyst.hr. A nice, finely evided, free flowing polyethylene powder was obtained. No reactor fouling occurred.

Example XIX a. Synthesis of supported catalyst

1 g MAO/Si0₂ were weighed in a 100 mL Schlenk vessel (MAO on silica PQ. MS3040, 24.7 wt% Al , obtained from Witco GmbH). 0.32 mL of a dry toluene solution of ( (Cp(SiMe₃)₂(EtNMe₂) )TiCl₂ (Example XVIII al) were added to the MAO/Si0₂ powder while stirring at room temperature. The light blue-green powder, that had remained dry during synthesis, was stirred for 90 min. under N₂. Then 15.9 mL dry toluene were added. The resulting slurry, with [Ti] = 2*10^~6 mol/mL, was used to polymerise ethylene.

b. Polymerisation with supported catalyst

In a catalyst dosing vessel 10-5 mol of the supported catalyst (Ti-based, Al/Ti = 284) were slurried in 100 mL pentamethylheptane during 1 minute.

The slurry was introduced into a IL reactor, that had been filled with 0,75 L PMH and 4*10^"4 mol trioctylaluminium (TOA) at 40 C and kept at a constant ethylene pressure of 6 bar. The activity was immediate. The reactor contents were heated from 40 to

80 C in 8 minutes, starting immediately after the catalyst had been introduced.

Catalyst activity amounted 405 gPE/g catalyst.hr. A nice, finely devided, free flowing polyethylene powder was obtained. No reactor fouling occurred.

Example XX a. Synthesis of (C,Me₄(SiMe_?CH₇PPH_?)TiCl₇ To 1.57 g (4.15 mmol) of {(2- diphenylphosphino-l-sila-1, 1- dimethyl)ethyl}tetramethylcyclopentadiene, dissolved in 10 mL of diethyl ether, 8.3 mL of lithium- diisopropylamide (0.5M in diethyl ether; 4.15 mmol) were added at -78°C. After 18 hours' stirring at room temperature, a turbid yellow/orange solution had formed. The diethyl ether was evaporated, and the residue was washed twice with petroleum ether. After this had been well boiled down, there remained 1.41 g of a pale-yellow crystalline product containing lithium { (2-diphenylphosphino-l-sila-l,1- dimethyl )ethyltetramethylcyclopentadienyl.

The organolithium compound was dissolved in 20 mL of tetrahydrofuran. Then the yellow/orange solution was added, at -78°C, to 1.36 g (3.76 mmol) of Ti (III)C1₃.3THF. The reaction mixture was then stirred for 3 hours in the cold bath and afterwards for 18 hours at room temperature. A dark-green solution had now formed, which was boiled down and washed twice with lOmL of petroleum ether. There now remained 1.5 g of a green solid containing l-{ (2-diphenylphosphino-l-sila- 1, 1-dimethyl )ethyl}-2,3,4,5- tetramethylcyclopentadienyl]titanium(III) diehloride.

b. Synthesis of supported catalyst 1.5 g MAO/Si0₂ were weighed in a 100 mL

Schlenk vessel (MAO on silica PQ MS3040, 24.7 wt% Al, obtained from Witco GmbH) and dried under a vacuum for 90 min. 0.58 mL of a dry toluene solution of 0.08 M (C_sMe₄(SiMe₂CH₂PPh₂)TiCl₂ were added to the remaining 1.45 g MAO/Si0₂ powder while stirring at room temperature. The light yellow powder, that had remained dry during synthesis, was stirred for 90 min. under N₂ at room temperature. Then 22.8 mL dry toluene were added. The resulting slurry, with [Ti] = 2*10~⁶ mol/mL, was used to polymerise ethylene.

c. Polymerisation with supported catalyst

In a catalyst dosing vessel 3*10^"5 mol of the supported catalyst (Ti-based, Al/Ti = 284) were slurried in 100 mL pentamethylheptane during 1 minute.

The slurry was introduced into a IL reactor, that had been filled with 0,75 L PMH and 4*10^-4 mol trioctylaluminium (TOA) at 90 C and kept at a constant ethylene pressure of 6 bar. The activity was immediate. The reactor temperature was set at 100 C. A free-flowing powder was obtained. No reactor fouling occurred. The Mw of the polymer produced was determined by GPC to amount 87 kg/mol, Mn = 30 kg/mol, MWD = 2.9.

Examples XXI-XXII

The preparation of the supported catalysts

I) A so-called wet method

At x grammes MAO/PQMS3040 silica (Witco GmbH) , 5 - 20x ml KPB (C₆-fraction hydrocarbon) were added. Then the required amount of metallocene, usually in toluene or KPB was added. It was made sure that the transition metal concentration in the resulting slurry was typically 5*10^~6 mol/ml. The slurry was used for polymerisation experiments. Entire synthesis was performed in the glove box, under nitrogen.

II) A so-called pore filling method

X grammes MAO/PQ MS3040 (Witco) were evacuated during 1.5 hrs (typical weight loss 5%, mainly organic solvents). Then a metallocene solution was added, typically about 30% of the total pore volume of the MAO/silica. After catalyst addition the solids were stirred during 1.5 hrs. Then a catalyst slurry was prepared. All syntheses were performed in the glove box.

General polymerisation procedure

A catalyst slurry with a Zr ,Ti-concentration of about 1 *10^~5 mol/ml was prepared. Polymerisation was performed in a glass Bϋchi reactor. In the 1.5 L reactor 750 mL pentamethylheptane was added, followed by 4*10~³ mol trioctylaluminium (TOA) as scavenger. The required amount of catalyst, usually between 5*10"⁶ mol and 2*10"⁵mol on transition metal basis, was introduced into the reactor at 40°C via a catalyst dosing vessel. The reactor was heated to 80°C. This took about 10 min. Then the polymerisation was performed for another 10 min., making the total polymerisation time 20 min. The ethylene pressure in the reactor was kept constant at 5 ato and the ethylene flow required to keep the pressure at 5 ato was determined. The polymerisation was stopped and the polymer slurry drained from the reactor. The polymer slurry was killed using methanol, stabilized by addition of Irganox 1076 and dried under reduced pressure at 50°C. The polymer yield was determined and the molecular weight studied by GPC, if reguired.

Example XXIa

The combination of Cp(SiMe₃)₇(EtNMe₇)TiCl_? (TMS-cat) and (CP^*^ (SiMe₇-CH₇)PPH₇)TiCl₇ (PPH-cat)

The TMS-cat was obtained according to the preparation method described in Example XVIIIa and the PPH-cat was obtained according to the method described in Example XXa. Synthesis: following synthesis route II) solutions of both catalysts in toluene were added simultaneously to the dry MAO/silica, under vigorous stirring. A light yellow powder was obtained. A catalyst slurry in toluene was prepared (2*10^~6 mol/ml). Under the standard conditions described under the general polymerisation procedure, but now from 40 to 100°C and with 4*10"⁴ mol TOA, a polymerisation was performed with 20 micromoles of catalyst, based on Ti. No. reactor fouling was observed. 43.4 g PE were formed in 20 min.

Mw = 1500 kg/mol, Mn = 165 kg/mol, Mz = 3500 kg/mol. The yield was 1.5 times higher than under XXIb.

Example XXIb The same catalyst was also introduced at

80°C, [TOA] = 4*10~⁴ mol/1, while polymerisation took 15 min .

The molecular weights of the particles formed were:

Mw = 950 kg/mol, Mn = 56 kg/mol, Mz = 2400 kg/mol.

Example XXII

The combination of the TMS-cat with rac-Et (1-Ind)_?ZrCl-, (Et (l-Ind)₂ZrCl₂ had been obtained from Witco GmbH)

A series of catalysts were prepared, ranging from the pure TMS catalyst to the pure zirconocene. Also two synthetic procedures, two silicas and two scavenger levels were compared. It is clear from the GPC that both metallocenes remain intact when combined.

a. Synthesis of the pure supported TMS catalyst on Witco 's MAO/PO MS3040 silica

Following synthesis route I), a catalyst was prepared with Al/Ti = 200, in kpb, slurry concentration 5*10^"6 mol/ml. A light green suspension in a colourless solvent was obtained. The catalyst was tested from 40- 80°C, [TOA] = 4*10^"4mol/l, total polymerisation time 20 min., catalyst yield 279 gPE/gcat.hr. Mw = 2600 kg/mol; Mn 870 kg/mol; Mz = 4800 kg/mol.

b. Synthesis of the pure supported TMS catalyst on Grace Sylopol 2104 silica. MAO/silica prepared by Witco Following synthesis route I), a catalyst was prepared with Al/Ti = 284, in kpb, slurry concentration 5*10~⁶ mol/ml. A light green suspension in a colourless solvent was obtained. The catalyst was tested from 40- 80°C. [TOA] = 4*10~³ mol/1, total polymerisation time 20 min. catalyst yield 250 g PE/g cat.hr. Mw = 2100 kg/mol; Mn = 390 kg/mol; Mz = 4000 kg/mol.

c. Synthesis of the pure supported rac-Et (1-Ind)_;ZrCl₂ on Witco's MAO/POMS3040 silica

Synthesis route I) was followed, ending up with a yellow suspension in KPB with concentration 2*10^~6 mol/ml and Al/Zr = 284. The catalyst was tested with 4*10^"3 mol TOA, from 40-80°C, 20 min polymerisation time. The catyield was 435 gPE/g cat.hr. Mw = 205 kg/mol; Mn = 47 kg/mol; Mz = 790 kg/mol.

d. Synthesis TMS/Et(1-Ind)₇ZrCl_? in the ratio 80/20 on MAO/POMS3040 silica

Following synthesis route I) the catalyst was synthesized by adding simultaneously solutions of both metallocenes to the MAO/silica slurry. A slurry of light green/yellowish powder in colourless solvent was obtained with a transition metal concentration of 5*10^"δ mol/ml . The catalyst was first tested with 4*10^~4 mol/1 TOA, from 40-80°C, 20 min. polymerisation time.

The product had an IV (decaline, 135°C) of 11.5 dl/g.

Secondly, the catalyst was tested in the same way with 4*10^~3 mol/1 TOA. Mw = 1400 kg/mol; Mn = 83 kg/mol; Mz = 4000 kg/mol.

e. Synthesis of TMS/Et (l-ind)_?ZrCl₇ in the ratio 50/50 on MAO/POMS3040 silica

Following synthesis route I) the catalyst was synthesized by adding simultaneously solutions of both metallocenes to the MAO/silica slurry. A slurry of bright, light green/yellowish particles in solvent was obtained with a transition metal concentration of 2*10^"6 mol/ml. The catalyst was tested as described under d. , with [TOA] = 4*10~³ mol/1. No reactor fouling occurred.

Mw = 740 kg/mol; Mn = 55 kg/mol; Mz = 3300 kg/mol.

f. Synthesis of TMS/Et(1-Ind)oZrCl_? in the ratio 20/80 on MAO/PQMS3040 silica according to the wet method described in synthesis route I)

The catalyst was synthesized and tested as described under e. Testing lasted 20 min. No reactor fouling occurred. Mw = 340 kg/mol; Mn = 43 kg/mol; Mz = 2000 kg/mol.

α. Synthesis of the catalyst described under F) using the pore filling method described in synthesis route

II) The catalyst was synthesized according to synthesis route II). A yellowish powder was obtained. A polymerisation was performed with 1.5 micromoles transition metal, following the polymerization procedure described under e). The constant polymerisation prophile resulted in a catalyst yield of 1080 gPE/g cat.hr.

Table 1 Examples of transition metal complexes according to the invention (see formulas I and VI) v

*

10

©

15

π

H ε i

00

Claims

WHAT IS CLAIMED IS:

1. A catalyst system comprising a carrier material, at least one transition metal complex, and one or more co-catalysts, wherein said reduced transition metal complex has the following structure:

X

I

M - L₂ I κ_m

wherein:

M is a reduced transition metal selected from group 4, 5 or 6 of the Periodic Table of the Elements; X is a multidentate monoanionic ligand represented by the formula (Ar-R_t-)_βY(-R_t- DR'n),; Y is a member selected from the group consisting of a cyclopentadienyl, amido (-NR'-), and phosphido (-PR'-) group;

R is at least one member selected from the group consisting of (i) a connecting group between the Y group and the DR'_n group and (ii) a connecting group between the Y group and the Ar group, wherein when the ligand X contains more than one R group, the R groups can be identical as or different from each other ; D is an electron-donating hetero atom selected from group 15 or 16 of the Periodic Table of

Elements; R' is a substituent selected from the group consisting of a hydrogen, hydrocarbon radical and hetero atom-containing moiety, except that R' cannot be hydrogen when R' is directly bonded to the electron-donating hetero atom D, wherein when the multidentate monoanionic ligand X contains more than one substituent R', the substituents R' can be identical or different from each other; Ar is an electron-donating aryl group; L is a monoanionic ligand bonded to the reduced transition metal M, wherein the monoanionic ligand L is not a ligand comprising a cyclopentadienyl, amido (-NR'-), or phosphido (-PR'-) group, and wherein the monoanionic ligands L can be identical or different from each other ; K is a neutral or anionic ligand bonded to the reduced transition metal M, wherein when the transition metal complex contains more than one ligand K, the ligands K can be identical or different from each other; m is the number of K ligands, wherein when the K ligand is an anionic ligand m is 0 for M³⁺, m is 1 for M⁴⁺, and m is 2 for M^s+, and when K is a neutral ligand m increases by one for each neutral K ligand; n is the number of the R' groups bonded to the electron-donating hetero atom D, wherein when D is selected from group 15 of the Periodic Table of Elements n is 2, and when D is selected from group 16 of the Periodic Table of Elements n is 1; q and s are the number of (-R_t-DR'_n) groups and (Ar-R_t-) groups bonded to group Y, respectively, wherein q + s is an integer not less than 1; and t is the number of R groups connecting each of (i) the Y and Ar groups and (ii) the Y and DR'_n groups, wherein t is selected independently as 0 or 1.

2. A catalyst system according to claim 1, wherein the Y group is a cyclopentadienyl group.

3. A catalyst system according to claim 2, wherein the cyclopentadienyl group is an unsubstituted or substituted indenyl, benzoindenyl, or fluorenyl group.

4. A catalyst system according to claim 2, wherein said reduced transition metal complex has the following structure:

Y - R - DR'_n

M(III) - L₂, I

wherein:

M(III) is a transition metal from group 4 of the Periodic Table of the Elements in oxidation state 3+.

5. A catalyst system according to claim 2, wherein said reduced transition metal is titanium.

6. A catalyst system according to claim 2, wherein said electron-donating hetero atom D is nitrogen.

7. A catalyst system according to claim 2, wherein the R' group in the DR'_n group is an n-alkyl group.

8. A catalyst system according to claim 2, wherein said R group has the following structure:

(-CR'₂-)_p,

wherein p is 1, 2, 3, or 4.

9. A catalyst system according to claim 2, wherein said monoanionic ligand L is selected from the group consisting of a halide, an alkyl group, and a benzyl group.

10. A catalyst system according to claim 2, wherein the Y group is a di-, tri- or tetraalkyl- cyclopentadienyl.

11. A catalyst system according to claim 2, wherein said co-catalyst comprises a linear or cyclic aluminoxane or a triaryl borane or tetraaryl borate.

12. A catalyst system according to claim 2, wherein at least one member selected from the group consisting of said reduced transition metal complex and said co-catalyst is supported on at least one carrier.

13. A process for the polymerization of α-olefin monomer(s), comprising contacting a mixture of said α-olefin monomer (s) in a liquid alkane or aromatic solvent with a catalyst system according to one of claims 1-12.

14. The process according to claim 13, wherein the α- olefin(s) is/are selected from the group consisting of ethene, propene, butene, pentene, hexene, heptene, octene, substituted styrene, non- substituted styrene and mixtures thereof.

15. The process according to claim 14, wherein said α- olefins comprise ethene and butene.

16. The process according to claim 14, wherein said α- olefins comprise ethene and hexene.

17. The process according to claim 14, wherein said α- olefins comprise ethene and octene.