Process for the polymerization of olefins using catalyst systems based on an organic transition metal complex

The present invention relates to a process for the polymerization of olefins in the presence of at least one catalyst comprising an organic transition metal complex.

To improve the property profile of polyolefins, it is being increasingly found to be necessary to achieve precise control of the molecular composition of the polyolefins. An important step forward in this direction was the development of single site catalysts in which only one type of catalytically active site is present. The polymers obtained using such catalysts have a relatively uniform distribution of the polymer chains with regard to the molar mass, the comonomer distribution and, if appropriate, the stereoregularity.

One class of these catalysts is made up of the chromium single site catalysts which are based on monocyclopentadienyl complexes. These can be used either alone or in combination with other catalysts as hybrid catalysts.

A significant factor influencing the properties of the polymerization catalysts or catalyst mixtures is their comonomer incorporation behavior. For a particular catalyst species, the comonomer incorporation behavior is essentially a fixed parameter. To be able to prepare a polymer having a different comonomer content, chromium single site catalysts have, like other single site catalysts, hitherto been modified by changing the substitution pattern of the cyclopentadienyl ligand, which is relatively expensive since a new catalyst is in each case ultimately formed.

Furthermore, it is known that the properties of the polymers formed in the polymerization of olefins can be influenced by the addition of auxiliaries which are frequently also referred to as modifiers. Mention may here be made of chain transfer regulators such as hydrogen which is generally used for regulating the mean molar mass of the polymer chains formed. Furthermore, it is known that other compounds can also be used for controlling the molar mass of polyolefins. For example, WO 95/13305 states that the molar mass of the polyolefins formed in the polymerization of olefins using supported metallocene catalysts can be increased by addition of electron donor compounds, while the molar mass is reduced when water or electron-pulling compounds are used.

It is known from EP-A 435 250 that dialkylzinc compounds act as molar mass regulators in the case of Ziegler catalysts and increase the activity of the catalysts. EP-A 1 092 730 describes such an effect of dialkylzinc compounds in reducing the molar mass and increasing the activity of the catalysts for metallocene catalysts, too. Furthermore, EP-A 1 092 730, WO 98/56835 and US-A 6 642 326 teach that silanes having a maximum of three radicals which are different from hydrogen also act as molar mass regulators and reduce the molar mass and at the same time

increase the activity of the catalysts. Substituted silanes in which at least one radical is an alkoxy or aryloxy group are known, for example from EP-A 447 959, as cocatalysts for Ziegler-Natta catalysts. WO 03/104290 discloses that in the case of single site catalysts comprising cyclopentadienyl ligands, appropriately substituted silanes lead to an increase in the molar mass of the polyolefins formed without the activity of the catalysts being reduced.

With regard to hybrid catalysts, WO 02/090398 describes a process for preparing polyolefins in one polymerization stage in which a hybrid catalyst and an auxiliary selected from the group consisting of phosphines, phosphites, acetylenes, dienes, thiophenes and aluminum alkyls is used. These auxiliaries influence the molar mass of the polymer components formed by the individual active sites, with the different active sites being influenced differently and a change in the ratio of high molecular weight component to low molecular weight component being made possible in this way. The auxiliaries can be used instead of or together with hydrogen. However, variations in the polymers produced can be obtained only to a very limited extent in this process, too, since although a variation in the molar mass of the polymer components is achieved, their properties otherwise remain unchanged.

In olefin polymerization processes which are carried out in a cascade of a plurality of reactors, it is possible to produce a plurality of polymer components which not only have a different molar mass but also a different content of comonomer. To prepare such products with the aid of hybrid catalysts in only one reactor, the comonomer incorporation behavior of the respective catalyst component in each case has to be structurally adapted, insofar as this is possible at all.

It was therefore an object of the present invention to prepare polymers having a different comonomer content or to be able to change the comonomer incorporation behavior in a targeted manner using one catalyst species.

It has now been found that when catalysts based on organic transition metal complexes are used, the comonomer incorporation behavior can be controlled by use of suitable auxiliaries.

The present invention accordingly provides a process for the polymerization of olefins in the presence of at least one catalyst comprising an organic transition metal complex, wherein the comonomer incorporation behavior of the catalyst is controlled by addition of one or more auxiliaries.

The addition of such compounds thus makes it possible to alter the comonomer content of the polymers prepared by means of the catalysts based on an organic transition metal complex in a targeted manner in order to produce polymers having different comonomer contents by means of one catalyst species.

Possible organic transition metal complexes are in principle all compounds of the transition metals of groups 3 to 12 of the Periodic Table or the lanthanides which comprise organic groups and usually form catalysts which are active in olefin polymerization after reaction with a cocatalyst and, if appropriate, organometallic compounds. These are usually compounds in which at least one monodentate or polydentate ligand is bound via a sigma or pi bond to the central atom.

Possible ligands include both those comprising cyclopentadienyl radicals and those which are free of cyclopentadienyl radicals. Chem. Rev. 2000, Vol. 100, No. 4 describes many such compounds which are suitable for olefin polymerization. Furthermore, multinuclear cyclopentadienyl complexes are also suitable for olefin polymerization.

For the purposes of the invention, the comonomer incorporation behavior is the ability of the respective catalyst or the respective catalyst component to incorporate comonomers in a ratio to the monomer. This can quantitatively be expressed by the copolymerization constant.

A preferred embodiment of the present invention comprises a process for the polymerization of olefins in the presence of at least one catalyst comprising a monocyclopentadienyl complex of the formula Cp-Y _m M ^A (I), where the variables have the following meanings:

Cp is a cyclopentadienyl system,

Y is a substituent which is bound to Cp and comprises at least one uncharged donor A, which comprises at least one atom of group 15 or 16 of the Periodic Table,

M ^A is titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum or tungsten, in particular chromium, and

m is 1 , 2 or 3.

Further preference is given to the one or more auxiliaries being selected from the group consisting of

a) silanes of the general formula R _a SiR' _b or R _a Si(OR') _b , b) zinc dialkyls of the general formula ZnR' _2l c) ethers of the general formula R'-O-R' and d) boron trialkyls of the general formula BR' ₃ ,

where

the radicals R are identical or different and are each a Ci-C ₂ o-alkyl, C ₆ -C ₂₀ -aryl, C ₆ -C ₂ o-arylalkyl or C ₆ -C ₂₀ -alkylaryl radical which is substituted by at least one polar group of the general

formula -NFT ₂ , -OR", -COR" or -COOR",

the radicals R' are identical or different and are each a Ci-C ₂ o-alkyl, C ₆ -C ₂ o-aryl, C ₆ -C ₂₀ -arylalkyl or

C ₆ -C ₂₀ -alkylaryl radical;

the radicals R" are identical or different and are each hydrogen or a C _r C ₂₀ -alkyl, C ₆ -C ₂₀ -aryl,

C ₆ -C ₂ o-arylalkyl or C ₆ -C ₂₀ -alkylaryl radical,

a is 1 , 2, 3 or 4 and

b is selected so that a + b = 4.

This is of particular interest when using hybrid catalysts, since it has been found that the monocyclopentadienyl-based catalysts react particularly strongly to the modifier, while other catalysts such as classical metallocene catalysts or in particular later transition metal catalysts are influenced less strongly in terms of their comonomer incorporation behavior.

The auxiliaries are preferably used individually, but can also be used together. The auxiliaries mentioned will hereinafter also be referred to collectively or alone as modifiers.

The amounts of modifier added serve, in particular, to alter the comonomer incorporation behavior of the catalyst. Depending on the modifier used, the mean molar mass of the catalyst can at the same time be increased or decreased in an appropriate way so as to obtain a polymer or polymer component having tailored properties. It may be emphasized that further additives and auxiliaries such as antistatics or scavengers can additionally be used in the process of the invention.

The modifiers are usually used in an amount of from 2 to 100 mol ppm, in each case based on the total reaction mixture. The precise amount of modifier used is, in particular, dependent on the sensitivity of the catalyst to the modifier and also on the type and amount of scavengers such as metal alkyls added. It therefore has to be matched empirically to the respective reaction conditions. The amount should in no case be so high that one or more catalyst components are completely deactivated, as is customary, for example, before the reactor is shut down.

The modifiers mentioned are preferably used in an amount of at least 3 mol ppm, more preferably at least 5 mol ppm, more preferably at least 8 mol ppm. Preference is given to using an amount of not more than 90 mol ppm, more preferably not more than 75 mol ppm, more preferably not more than 50 mol ppm. A preferred concentration range extends from 3 to 80 mol ppm, more preferably from 3 to 60 mol ppm, particularly preferably from 5 to 40 mol ppm.

Apart from the modifiers mentioned, further auxiliaries, in particular modifiers, which preferably

have a different selectivity toward the catalyst components can additionally be present. The addition of further modifiers can be particularly useful when the hybrid catalyst also comprises more than two components.

Preference is given to modifiers selected from the group consisting of

a) silanes of the general formula R _a SiR' _b or R _a Si(OR') _b , b) zinc dialkyls of the general formula ZnR' ₂ , c) ethers of the general formula R'-O-R ¹ and d) boron trialkyls of the general formula BR' ₃ ,

where the radicals R, R' and R" are as defined above.

Preferred silanes R _a SiR' _b or R _a Si(OR') _b are those in which

the radicals R are identical or different and are each a Ci-C ₂ o-alkyl radical which is substituted by at least one polar group of the general formulae -NR" ₂ , -OR", -COR" or -COOR",

the radicals R ¹ are identical or different and are each a C ₁ -C ₂₀ -BlKyI radical and

the radicals R" are identical or different and are each hydrogen or a C _r C ₂₀ -alkyl radical.

Preferred substituents R are methylamino, ethylamino, n-propylamino, isopropylamino, butylamino and hexylamino radicals. Particular preference is given to N,N-(diethylamino)trimethyl- silane, 3-aminopropyltrimethylsilane, bis(dimethylamino)dimethylsilane, anilinotrimethylsilane.

Preferred zinc dialkyls ZnR' ₂ are those in which the radicals R' are each, independently of one another, methyl, ethyl, n-propyl, isopropyl, butyl, hexyl or cyclohexyl. Particular preference is given to diethylzinc.

Preferred ethers R'-O-R' are, in particular, those in which the radicals R' are each, independently of one another, methyl, ethyl, propyl, butyl, pentyl, hexyl. Particular preference is given to butyl methyl ether and diethyl ether.

Preferred boron trialkyls BR' ₃ are those in which the radicals R' are each, independently of one another, methyl, ethyl, propyl, isopropyl or butyl. Particular preference is given to triethylboron.

According to the invention, catalysts based on organic transition metal complexes are used. These are frequently also referred to as single site catalysts, since they are based on a chemically uniform complex.

The catalysts comprising monocyclopentadienyl complexes preferably comprise the structural element of the general formula Cp-Y _m M ^λ (I), where the variables have the following meanings:

Cp is a cyclopentadienyl system,

Y is a substituent which is bound to Cp and comprises at least one uncharged donor D, which comprises at least one atom of group 15 or 16 of the Periodic Table,

M ^A is titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum or tungsten, in particular chromium, and

m is 1 , 2 or 3.

Further ligands can also be bound to the metal atom M ^A . The number of further ligands depends, for example, on the oxidation state of the metal atom. The further ligands are not further cyclopentadienyl systems. Suitable ligands are monoanionic and dianionic ligands as are described, for example, for X. In addition, Lewis bases such as amines, ethers, ketones, aldehydes, esters, sulfides or phosphines can also be bound to the metal center M. The monocyclopentadienyl complexes can be monomeric, dimeric or oligomeric. The monocyclopentadienyl complexes are preferably present in monomeric form.

M ^A is a metal selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten. The oxidation states of the transition metals M ^A in catalytically active complexes are mostly known to those skilled in the art. Chromium, molybdenum and tungsten are very probably present in the oxidation state +3, zirconium and hafnium in the oxidation state +4 and titanium in the oxidation state +3 or +4. However, it is also possible to use complexes whose oxidation state does not correspond to that of the active catalyst. Such complexes can then be appropriately reduced or oxidized by means of suitable activators. M ^A is preferably titanium in the oxidation state +3, vanadium, chromium, molybdenum or tungsten. Particular preference is given to chromium in the oxidation states +2, +3 and +4, in particular +3.

m can be 1 , 2 or 3, i.e. 1 , 2 or 3 donor-comprising substituents Y can be bound to Cp. When 2 or 3 substituents Y are present, these can be identical or different. Preference is given to only one substituent Y being bound to Cp (m = 1).

The substituent Y bound to Cp comprises at least one uncharged donor A. A is an uncharged functional group comprising an element of group 15 or 16 of the Periodic Table, e.g. amine, imine, carboxamide, carboxylic ester, ketone (oxo), ether, thioketone, phosphine, phosphite, phosphine oxide, sulfonyl, sulfonamide, or an unsubstituted, substituted or fused, partially unsaturated

heterocyclic or heteroaromatic ring system. The donor A can be bound intermolecularly or intramolecularly to the transition metal M ^A or not be bound to it. The donor A is preferably bound intramolecularly to the metal center M ^A . Particular preference is given to monocyclopentadienyl complexes which comprise the structural element of the general formula Cp-Y-M ^A .

Cp is a cyclopentadienyl system which may be substituted in any desired way and/or be fused with one or more aromatic, aliphatic, heterocyclic or heteroaromatic rings, with 1 , 2 or 3 substituents, preferably 1 substituent, being formed by the group Y and/or 1 , 2 or 3 substituents, preferably 1 substituent, being substituted by the group Y and/or the aromatic, aliphatic, heterocyclic or heteroaromatic fused ring bearing 1 , 2 or 3 substituents Y, preferably 1 substituent Y. The cyclopentadienyl skeleton itself is a C ₅ ring system having 6 π electrons, with one of the carbon atoms also being able to be replaced by nitrogen or phosphorus, preferably phosphorus. Preference is given to using C ₅ ring systems which do not have a carbon atom replaced by a heteroatom. It is possible, for example, for a heteroaromatic comprising at least one atom of the group consisting of N, P, O and S or an aromatic to be fused to this cyclopentadienyl skeleton. In this context, "fused to" means that the heterocycle and the cyclopentadienyl skeleton share two atoms, preferably carbon atoms. The cyclopentadienyl system is bound to M ^A .

Particularly useful monocyclopentadienyl complexes are ones in which Y is formed by the group -Zk-A- and together with the cyclopentadienyl system Cp and M ^A forms a monocyclopentadienyl complex comprising the structural element of the general formula Cp-Zk-A-M ^A (II), where the variables have the following meanings:

where the variables have the following meanings:

E ^1A -E ^5A are each carbon or not more than one E ^1A to E ^5A is phosphorus,

R ^1A -R ^4A are each, independently of one another, hydrogen, Ci-C ₂₂ -alkyl, C ₂ -C ₂₂ -alkenyl,

C ₆ -C ₂₂ -aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, NR ^5A ₂ , N(SiR ^5A ₃ ) ₂ , OR ^5A , OSiR ^5A ₃ , SiR ^5A ₃ , BR ^5A ₂ , where the organic radicals R ^1A -R ^4A may also be substituted by halogens and two vicinal radicals R ^1A -R ^4A may also be joined to form a five-, six- or seven-membered ring, and/or two vicinal radicals R ^1A -R ^4A are joined to form a five-, six- or seven-

membered heterocycle which comprises at least one atom from the group consisting of N, P, O and S,

,5A the radicals R are each, independently of one another, hydrogen, CrC _∑ o-alkyl, C ₂ -C ₂ o-alkenyl, C ₆ -C ₂ o-aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical and two geminal radicals R ^5A may also be joined to form a five- or six-membered ring,

is a divalent bridge between A and Cp selected from the group consisting of

_R 6A

R ^6A R ^8A 8A _R 10A

R ^6A R

1A 1A 2A 1A 2A . 3A

L I L I L

_? 7A _R 7A _R 9A 7A 9A ,11A

F F F F F F

_BR ^6A -, -BNR ^6A R ^7A -, -AIR ^6A -, -Sn-, -O-, -S-, -SO-, -SO ₂ -, -NR ^6A - -CO-,

-PR ^6A - or -P(O)R ^6A - where

L ^1A -L ^3A are each, independently of one another, silicon or germanium,

_R ^6A _ _R ^{i iA} _{are each} j _nc | _e p _enc | _en tiy _o f one another, hydrogen, d-C _∑ o-alkyl, C ₂ -C ₂₀ - alkenyl, C ₆ -C ₂ o-aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical

12A and 6-20 carbon atoms in the aryl radical or SiR ₃ , where the organic radicals R ^6A -R ^11A may also be substituted by halogens and two geminal or vicinal radicals

R -R may also be joined to form a five- or six-membered ring and

the radicals R ^12A are each, independently of one another, hydrogen, d-C^-alkyl, C ₂ -C ₂ o-alkenyl, C ₆ -C ₂ o-aryl or alkylaryl having from 1 to 10 carbon atoms

in the alkyl radical and 6-20 carbon atoms in the aryl radical, C ₁ -Ci ₀ - alkoxy or C ₆ -C ₁₀ -aryloxy and two radicals R ^12A may also be joined to form a five- or six-membered ring, and

A is an uncharged donor group comprising one or more atoms of group 15 and/or 16 of the Periodic Table of the Elements, preferably an unsubstituted, substituted or fused, heteroaromatic ring system,

M ^A is a metal selected from the group consisting of titanium in the oxidation state 3, vanadium, chromium, molybdenum and tungsten, in particular chromium, and

k is O or l

In preferred cyclopentadienyl systems Cp, all E ^1A to E ^5A are carbon.

The polymerization behavior of the metal complexes can be influenced by varying the substituents R ^1A -R ^4A . The type and number of the substituents can influence the ability of the olefins to be polymerized to gain access to the metal atom M ^A . It is possible in this way to modify the activity and selectivity of the catalyst in respect of various monomers, in particular bulky monomers. Since the substituents can also influence the rate of termination reactions of the growing polymer chain, the molecular weight of the polymers being formed can also be altered in this way. The chemical structure of the substituents R ^1A to R ^4A can therefore be varied widely, in order to achieve the desired results and to obtain a tailored catalyst system. Examples of possible carboorganic substituents R ^1A -R ^4A are the following: hydrogen, Ci-C ₂₂ -alkyl which may be linear or branched, e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n- octyl, n-nonyl, n-decyl or n-dodecyl, 5- to 7-membered cycloalkyl which may in turn bear a C ₁ -Ci ₀ - alkyl group and/or a C ₆ -C ₁₀ -aryl group as substituent, e.g. cyclopropyl, cyclobutyl, cyciopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclododecyl, C ₂ -C ₂ 2-alkenyl which may be linear, cyclic or branched and in which the double bond can be internal or terminal, e.g. vinyl, 1- allyl, 2-allyl, 3-allyl, butenyl, pentenyl, hexenyl, cyclopentenyl, cyclohexenyl, cyclooctenyl or cyclooctadienyl, C ₆ -C ₂ 2-aryl which may be substituted by further alkyl groups, e.g. phenyl, naphthyl, biphenyl, anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5-, or 2,6-dimethylphenyl, 2,3,4- , 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or 3,4,5-trimethylphenyl, and arylalkyl which may be substituted by further alkyl groups, e.g. benzyl, o-, m-, p-methylbenzyl, 1- or 2-ethylphenyl, where two of the radicals R ^1A to R ^4A may also be joined to form a 5-, 6- or 7-membered ring and/or two of the vicinal radicals R ^1A -R ^4A may be joined to form a five-, six- or seven-mem bered heterocycle which comprises at least one atom from the group consisting of N, P, O or S and/or the organic radicals R ^1A -R ^4A may also be substituted by halogens such as fluorine, chlorine or bromine. Furthermore, _R ^1A _ _R ^4A _{can a} | _{S0 be am} j _no NR ^5A _{2I or} N(SiR ^5A ₃ ) ₂ , alkoxy or aryloxy OR ^5A , for example dimethylamino, N-pyrrolidinyl, picolinyl, methoxy, ethoxy or isopropoxy. In organosilicon

substituents SiR ^5A ₃ , the radicals R ^5A can be the same carboorganic radicals as described in more detail above for R ^1A -R ^4A , where two R ^5A may also be joined to form a 5- or 6-membered ring, e.g. trimethylsilyl, triethylsilyl, butyldimethylsilyl, tributylsilyl, tri-tert-butylsilyl, triallylsilyl, triphenylsilyl or dimethylphenylsilyl. These SiR ^5A ₃ radicals can also be bound to the cyclopentadienyl skeleton via an oxygen or nitrogen, for example trimethylsilyloxy, triethylsilyloxy, butyldimethylsilyloxy, tributylsilyloxy or tri-tert-butylsilyloxy. Preferred radicals R ^1A -R ^4A are hydrogen, methyl, ethyl, n- propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, vinyl, allyl, benzyl, phenyl, ortho-dialkyl- or -dichloro-substituted phenyls, trialkyl- or trichloro-substituted phenyls, naphthyl, biphenyl and anthranyl. Particularly useful organosilicon substituents are trialkylsilyl groups having from 1 to 10 carbon atoms in the alkyl radical, in particular trimethylsilyl groups.

Two vicinal radicals R ^1A -R ^4A together with the atoms E ^1A -E ^5A bearing them can form a heterocycle, preferably a heteroaromatic, which comprises at least one atom from the group consisting of nitrogen, phosphorus, oxygen and sulfur, particularly preferably nitrogen and/or sulfur, with preference being given to the atoms E ^1A -E ^5A present in the heterocycle or heteroaromatic being carbon. Preference is given to heterocycles and heteroaromatics having a ring size of 5 or 6 ring atoms. Examples of 5-membered heterocycles which may comprise from one to four nitrogen atoms and/or a sulfur or oxygen atom in addition to carbon atoms as ring members are 1 ,2-dihydrofuran, furan, thiophene, pyrrole, isoxazole, 3-isothiazole, pyrazole, oxazole, thiazole, imidazole, 1 ,2,4-oxadiazole, 1 ,2,5-oxadiazole, 1 ,3,4-oxadiazole, 1 ,2,3-triazole and 1 ,2,4-triazole. Examples of 6-membered heteroaryl groups which may comprise from one to four nitrogen atoms and/or a phosphorus atom are pyridine, phosphobenzene, pyridazine, pyrimidine, pyrazine, 1 ,3,5-triazine, 1 ,2,4-triazine or 1 ,2,3-triazine. The 5-membered and 6- membered heterocycles can also be substituted by Ci-C ₁₀ -alkyl, C ₆ -C ₁₀ -aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6-10 carbon atoms in the aryl radical, trialkylsilyl or halogens such as fluorine, chlorine or bromine, dialkylamide, alkylarylamide, diarylamide, alkoxy or aryloxy or be fused with one or more aromatics or heteroaromatics. Examples of benzo-fused 5-membered heteroaryl groups are indole, indazole, benzofuran, benzothiophene, benzothiazole, benzoxazole and benzimidazole. Examples of benzo-fused 6-membered heteroaryl groups are chromane, benzopyran, quinoline, isoquinoline, cinnoline, phthalazine, quinazoline, quinoxaline, 1 ,10-phenanthroline and quinolizine. Naming and numbering of the heterocycles has been taken from Lettau, Chemie der Heterocyclen, 1st edition, VEB, Weinheim 1979. The heterocycles/heteroaromatics are preferably fused with the cyclopentadienyl skeleton via a C-C double bond of the heterocycle/heteroaromatic. Heterocycles/heteroaromatics having one heteroatom are preferably 2,3- or b-fused.

Cyclopentadienyl systems Cp having a fused heterocycle are, for example, thiapentalene, 2- methylthiapentalene, 2-ethylthiapentalene, 2-isopropylthiapentalene, 2-n-butylthiapentalene, 2- tert-butylthiapentalene, 2-trimethylsilylthiapentalene, 2-phenylthiapentalene, 2- naphthylthiapentalene, 3-methylthiopentalene, 4-phenyl-2,6-dimethyl-1-thiopentalene, 4-phenyl-

2,6-diethyl-1 -thiopentatene, 4-phenyl-2,6-diisopropyl-1-thiopentalene, 4-phenyl-2,6-di-n-butyl-1- thiopentalene, 4-phenyl-2,6-di(trimethylsilyl)-1-thiopentalene, azapentalene, 2- methylazapentalene, 2-ethylazapentalene, 2-isopropylazapentalene, 2-n-butylazapentalene, 2- trimethylsilylazapentalene, 2-phenylazapentalene, 2-naphthylazapentalene, 1-phenyl-2,5- dimethyl-1 -azapentalene, 1-phenyl-2,5-diethyl-1 -azapentalene, 1-phenyl-2,5-di-n-butyl-1- azapentalene, 1-phenyl-2,5-di-tert-butyl-1 -azapentalene, 1-phenyl-2,5-di(trimethylsilyl)-1- azapentalene, 1-tert-butyl-2,5-dimethyl-1 -azapentalene, oxapentalene, phosphapentalene, 1 -phenyl-2,5-dimethyl-1 -phosphapentalene, 1 -phenyl-2,5-diethyl-1 -phosphapentalene, 1 -phenyl- 2, 5-di-n-butyl-1 -phosphapentalene, 1-phenyl-2,5-di-tert-butyl-1 -phosphapentalene, 1-phenyl-2,5- di(trimethylsilyl)-1 -phosphapentalene, 1 -methyl-2,5-dimethyl-1 -phosphapentalene, 1 -tert-butyl- 2, 5-dimethyl-1 -phosphapentalene, 7-cyclopenta[1 ,2]thiopheno[3,4]cyclopentadiene or 7-cyclopenta[1 ,2]pyrrolo[3,4]cyclopentadiene.

In further preferred cyclopentadienyl systems Cp, the four radicals R ^1A -R ^4A , i.e. two pairs of vicinal radicals, form two heterocycles, in particular heteroaromatics. The heterocyclic systems are the same as those described in more detail above. Cyclopentadienyl systems Cp having two fused heterocycles are, for example, 7-cyclopentadithiophene, 7-cyclopentadipyrrole or 7-cyclopentadiphosphol.

The synthesis of such cyclopentadienyl systems having a fused-on heterocycle is described, for example, in the abovementioned WO 98/22486. In "metalorganic catalysts for synthesis and polymerisation", Springer Verlag 1999, Ewen et al., p.150 ff, describe further syntheses of these cyclopentadienyl systems.

Particularly preferred substituents R ^1A -R ^4A are the above-described carboorganic substituents and the carboorganic substituents which form a cyclic fused ring system, i.e. together with the E ^1A -E ^5A skeleton, preferably together with a C ₅ -cyclopentadienyl skeleton, form, for example, an unsubstituted or substituted indenyl, benzindenyl, phenanthrenyl, fluorenyl or tetrahydroindenyl system, and in particular their preferred embodiments.

Examples of such cyclopentadienyl systems (without the group -Z-A-, which is preferably located in the 1 position) are 3-methylcyclopentadienyl, 3-ethylcyclopentadienyl, 3-isopropyl- cyclopentadienyl, 3-tert-butylcyclopentadienyl, dialkylcyclopentadienyl systems, e.g. tetrahydroindenyl, 2,4-dimethylcyclopentadienyl or 3-methyl-5-tert-butylcyclopentadienyl, or trialkylcyclopentadienyl systems, e.g. 2,3,5-trimethylcyclopentadienyl or tetraalkylcyclo- pentadienyl systems, e.g. 2,3,4,5-tetramethylcyclopentadienyl, and indenyl, 2-methylindenyl, 2- ethylindenyl, 2-isopropylindenyl, 3-methylindenyl, benzoindenyl or 2-methylbenzoindenyl. The fused ring system may bear further CrC _∑ o-alkyl, C ₂ -C ₂ o-alkenyl, C ₆ -C ₂ o-aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, NR ^5A ₂ , N(SiR ^5A ₃ ) ₂ , OR ^5A , OSiR ^5A ₃ or SiR ^5A ₃ substituents, e.g. 4-methylindenyl, 4-ethylindenyl, 4-

isopropylindenyl, 5-methylindenyl, 4-phenylindenyl, 5-methyl-4-phenylindenyl, 2-methyl-4- phenylindenyl or 4-naphthylindenyl.

In a particularly preferred embodiment, one of the substituents R ^1A -R ^4A , preferably R ^2A , is a C ₆ -C ₂₂ -aryl group or an alkylaryl group having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, preferably a C ₆ -C ₂₂ -aryl group such as phenyl, naphthyl, biphenyl, anthracenyl or phenanthrenyl, where the aryl may also be substituted by N-, P-, O- or S-containing substituents, C ₁ -C ₂₂ -BlKyI, C ₂ -C ₂₂ -alkenyl, halogens or haloalkyls or haloaryls having 1-10 carbon atoms, for example o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5- or 2,6-dimethylphenyl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or 3,4,5-trimethylphenyl, o-, m-, p-dimethylaminophenyl, o-, m-, p-methoxyphenyl, o-, m-, p-fluorophenyl, o-, m-, p-chlorophenyl, o-, m-, p-trifluoromethylphenyl, 2,3-, 2,4-, 2,5-, or 2,6-difluorophenyl, 2,3-, 2,4-, 2,5- or 2,6-dichlorophenyl or 2,3-, 2,4-, 2,5-, or 2,6-di(trifluoromethyl)phenyl. The N-, P-, O- or S-containing substituents, d-C ₂₂ -alkyl, C ₂ -C ₂₂ - alkenyl, halogens or haloalkyls or haloaryls having 1 -10 carbon atoms as substituents on the aryl radical are preferably located in the para position relative to the bond to the cyclopentadienyl ring. The aryl substituent can be bound in the vicinal position to the substituent -Z-A or the two substituents are located in the 1 ,3 position relative to one another on the cyclopentadienyl ring. Preference is given to -Z-A and the aryl substituent being located in the 1 ,3 positions relative to one another on the cyclopentadienyl ring.

The monocyclopentadienyl complexes can be chiral. Thus, either one of the substituents R ^1A -R ^4A on the cyclopentadienyl skeleton can bear one or more chiral centers or else the cyclopentadienyl system Cp can itself be enantiotopic, so that the chirality is induced only when it is bound to the transition metal M (for the conventions regarding chirality in cyclopentadienyl compounds, see R. Halterman, Chem. Rev. 92, (1992), 965-994).

The bridge Z between the cyclopentadienyl system Cp and the uncharged donor A is, if present (k = 1), an organic divalent bridge, preferably consisting of carbon- and/or silicon- and/or boron- comprising bridge members. Changing the length of the link between the cyclopentadienyl system and A enables the activity of the catalyst to be influenced. Z is preferably bound in addition to the fused heterocycle or fused-on aromatics to the cyclopentadienyl skeleton. Thus, if the heterocycle or aromatic is fused on in the 2,3 positions of the cyclopentadienyl skeleton, then Z is preferably located in the 1 or 4 position of the cyclopentadienyl skeleton.

Possible carboorganic substituents R ^6A -R ^11A on the link Z are, for example, the following: hydrogen, Ci-C ₂ o-alkyl which may be linear or branched, e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl, 5- to 7-membered cycloalkyl which may in turn bear a C ₆ -C ₁₀ -aryl group as substituent, e.g. cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclododecyl, C ₂ -C ₂₀ -alkenyl which may be linear, cyclic or branched and in which the double

bond can be internal or terminal, e.g. vinyl, 1-allyl, 2-allyl, 3-allyl, butenyl, pentenyl, hexenyl, cyclopentenyl, cyclohexenyl, cyclooctenyl or cyclooctadienyl, C ₆ -C ₂₀ -aryl which may be substituted by further alkyl groups, e.g. phenyl, naphthyl, biphenyl, anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5-, or 2,6-dimethylphen-i-yl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or 3,4,5-trimethylphen-1-yl, or arylalkyl which may be substituted by further alkyl groups, e.g. benzyl, o-, m-, p-methylbenzyl, 1- or 2-ethylphenyl, where two radicals R ^6A to R ^11A may also be joined to form a 5- or 6-membered ring, for example cyclohexane, and the organic radicals R ^6A -R ^11A may also be substituted by halogens such as fluorine, chlorine or bromine, for example pentafluorophenyl or bis-3,5-trifluoromethylphen-1-yl, and alkyl or aryl.

In organosilicon substituents SiR ^12A ₃ , possible radicals R ^12A are the same radicals mentioned in more detail above for R ^6A -R ^11A , where two radicals R ^12A may also be joined to form a 5- or 6- membered ring, e.g. trimethylsilyl, triethylsilyl, butyldimethylsilyl, tributylsilyl, tri-tert-butylsilyl, triallylsilyl, triphenylsilyl or dimethylphenylsilyl. Preferred radicals R ^6A -R ^11A are hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, benzyl, phenyl, ortho-dialkyl- or -dichloro-substituted phenyls, trialkyl- or trichloro-substituted phenyls, naphthyl, biphenyl and anthranyl.

Particularly preferred substituents R ^6A to R ^11A are hydrogen, Ci-C ₂ o-alkyl which may be linear or branched, e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl C ₆ -C ₂ o-aryl which may be substituted by further alkyl groups, e.g. phenyl, naphthyl, biphenyl, anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5-, or 2,6-dimethylphen-1-yl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or 3,4,5-trimethylphen-1-yl, or arylalkyl which may be substituted by further alkyl groups, e.g. benzyl, o-, m-, p-methylbenzyl, 1- or 2-ethylphenyl, where two radicals R ^6A to R ^11A may also be joined to form a 5- or 6-membered ring, for example cyclohexane, and the organic radicals R ^6A -R ^2B may also be substituted by halogens such as fluorine, chlorine or bromine, in particular fluorine, for example pentafluorophenyl or bis- 3,5-trifluoromethylphen-1-yl, and alkyl or aryl. Particular preference is given to methyl, ethyl, 1 -propyl, 2-isopropyl, 1 -butyl, 2-tert-butyl, phenyl and pentafluorophenyl.

Z is preferably a -CR ^6A R ^7A -, -SiR ^6A R ^7A - group, in particular -Si(CH ₃ J ₂ -, -CR ^6A R ^7A CR ^8A R ^9A -, -SiR ^6A R ^7A CR ^8A R ^9A - or substituted or unsubstituted 1 ,2-phenylene and in particular -CR ^6A R ^7A -. Here, the preferred embodiments of the substituents R ^6A to R ^11A described above are likewise preferred embodiments. -CR ^6A R ^7A - is preferably a -CHR ^6A -, -CH ₂ - or -C(CH ₃ ) ₂ - group. The group -SiR ^6A R ^7A - in -L ^1A R ^6A R ^7A CR ^8A R ^9A - can be bound to the cyclopentadienyl system or to A. This group -SiR ^6A R ^7A - or its preferred embodiments is preferably bound to Cp.

k is 0 or 1 , and is in particular equal to 1 or when A is an unsubstituted, substituted or fused, heterocyclic ring system can also be 0. K is preferably equal to 1.

A is an uncharged donor comprising an atom of group 15 or 16 of the Periodic Table, preferably one or more atoms selected from the group consisting of oxygen, sulfur, nitrogen and phosphorus, preferably nitrogen and phosphorus. The donor function in A can be bound intermolecularly or intramolecularly to the metal M ^A . The donor in A is preferably bound intramolecularly to M. Possible donors are uncharged functional groups comprising an element of group 15 or 16 of the Periodic Table, e.g. amine, imine, carboxamide, carboxylic ester, ketone (oxo), ether, thioketone, phosphine, phosphite, phosphine oxide, sulfonyl, sulfonamide or unsubstituted, substituted or fused, heterocyclic ring systems. The synthesis of the bond from A to the cyclopentadienyl radical and Z can be carried out, for example, by a method analogous to that Of WO 00/35928.

A is preferably a group selected from among -OR ^13A -, -SR ^13A -, -NR ^13A R ^14A -, -PR ^13A R ^14A -, -C=NR ^13A - and unsubstituted, substituted or fused heteroaromatic ring systems, in particular -NR ^13A R ^14A -, -C=NR ^13A - and unsubstituted, substituted or fused heteroaromatic ring systems.

R ^13A and R ^14A are each, independently of one another, hydrogen, C _r C ₂ o-alkyl which may be linear or branched, e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl, 5- to 7-membered cycloalkyl which may in turn bear a C ₆ -Ci ₀ -aryl group as substituent, e.g. cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclododecyl, C ₂ -C ₂ o-alkenyl which may be linear, cyclic or branched and in which the double bond may be internal or terminal, e.g. vinyl, 1-allyl, 2-allyl, 3-allyl, butenyl, pentenyl, hexenyl, cyclopentenyl, cyclohexenyl, cyclooctenyl or cyclooctadienyl, C ₆ -C ₂ o-aryl which may be substituted by further alkyl groups, e.g. phenyl, naphthyl, biphenyl, anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5-, or 2,6-dimethylphen-1-yl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or 3,4,5-trimethylphen-1-yl, alkylaryl which has from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical and may be substituted by further alkyl groups, e.g. benzyl, o-, m-, p-methylbenzyl, 1- or 2-ethylphenyl, or SiR ^15A ₃ , where the organic radicals R ^13A -R ^14A may also be substituted by halogens, e.g. fluorine, chlorine or bromine, or nitrogen-comprising groups and further Ci-C ₂₀ -alkyl, C ₂ -C ₂₀ -alkenyl, C ₆ -C ₂₀ -aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical or SiR ^15A ₃ groups and two vicinal radicals R ^13A -R ^14A may also be joined to form a five- or six-membered ring and the radicals R ^15A are each, independently of one another, hydrogen, d-C^-alkyl, C ₂ -C ₂₀ - alkenyl, C ₆ -C ₂₀ -aryl or alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical or two radicals R ^15A may also be joined to form a five- or six- membered ring.

_NR ^i3A _R ^i4A _{js an am} j _de substituent. It is preferably a secondary amide such as dimethylamide, N-ethylmethylamide, diethylamide, N-methylpropylamide, N-methylisopropylamide, N-ethylisopropylamide, dipropylamide, diisopropylamide, N-methylbutylamide, N-ethylbutylamide, N-methyl-tert-butylamide, N-tert-butylisopropylamide, dibutylamide, di-sec-butylamide,

diisobutylamide, tert-amyl-tert-butylamide, dipentylamide, N-methylhexylamide, dihexylamide, tert- amyl-tert-octylamide, dioctylamide, bis(2-ethylhexyl)amide, didecylamide, N-methyloctadecylamide, N-methylcyclohexylamide, N-ethylcycIohexylamide, N-isopropylcyclohexylamide, N-tert-butylcyclohexylamide, dicyclohexylamide, pyrrolidine, piperidine, hexamethylenimine, decahydroquinoline, diphenylamine, N-methylanilide or N-ethylanilide.

In the imino group -C=NR ^13A , R ^13A is preferably a C ₆ -C ₂ o-aryl radical which may be substituted by further alkyl groups, e.g. phenyl, naphthyl, biphenyl, anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5-, or 2,6-dimethylphen-1-yl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or 3,4,5-trimethylphen-1-yl.

A is preferably an unsubstituted, substituted or fused heteroaromatic ring system which may comprise, apart from carbon ring atoms, heteroatoms from the group consisting of oxygen, sulfur, nitrogen and phosphorus. Examples of 5-membered heteroaryl groups which may, in addition to carbon atoms, comprise from one to four nitrogen atoms or from one to three nitrogen atoms and/or one sulfur or oxygen atom as ring members are 2-furyl, 2-thienyl, 2-pyrrolyl, 3-isoxazolyl, 5-isoxazolyl, 3-isothiazolyl, 5-isothiazolyl, 1-pyrazolyl, 3-pyrazolyl, 5-pyrazolyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl, 1 ,2,4-oxadiazol-3-yl, 1 ,2,4-oxadiazol-5-yl, 1 ,3,4-oxadiazol-2-yl or 1 ,2,4-triazol-3-yl. Examples of 6-membered heteroaryl groups which can comprise from one to four nitrogen atoms and/or a phosphorus atom are 2-pyridinyl, 2-phosphabenzolyl 3-pyridazinyl, 2-pyrimidinyl, 4-pyrimidinyl, 2-pyrazinyl, 1 ,3,5-triazin-2-yl and 1 ,2,4-triazin-3-yl, 1 ,2,4-triazin-5-yl or 1 ,2,4-triazin-6-yl. The 5-membered and 6-membered heteroaryl groups can also be substituted by C ₁ -C ₁₀ ^IKyI, C ₆ -C ₁₀ - aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6-10 carbon atoms in the aryl radical, trialkylsilyl or halogens such as fluorine, chlorine or bromine or be fused with one or more aromatics or heteroaromatics. Examples of benzo-fused 5-membered heteroaryl groups are 2-indolyl, 7-indolyl, 2-coumaronyl, 7-coumaronyl, 2-thianaphthenyl, 7-thianaphthenyl, 3-indazolyl, 7-indazolyl, 2-benzimidazolyl and 7-benzimidazolyl. Examples of benzo-fused 6-membered heteroaryl groups are 2-quinolyl, 8-quinolyl, 3-cinnolyl, 8-cinnolyl, 1-phthalazyl, 2-quinazolyl, 4-quinazolyl, 8-quinazolyl, 5-quinoxalyl, 4-acridyl, 1-phenanthridyl or 1-phenazyl. Naming and numbering of the heterocycles has been taken from L. Fieser and M. Fieser, Lehrbuch der organischen Chemie, 3rd revised edition, Verlag Chemie, Weinheim 1957.

Among these heteroaromatic systems A, particular preference is given to unsubstituted, substituted and/or fused 6-membered heteroaromatics having 1 , 2, 3, 4 or 5 nitrogen atoms in the heteroaromatic part, in particular substituted and unsubstituted 2-pyridyl or 2-quinolyl. A is therefore preferably a group of the formula (IV)

where

E ^6A -E ^9A are each, independently of one another, carbon or nitrogen,

_R ^i6A _ _R ^i9A _{are each^} j _n( j _e p _enc | _en tiy _o f one another, hydrogen, C ₁ -C ₂₀ -alkyl, C ₂ -C ₂ o-alkenyl,

C ₆ -C ₂₀ -aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical or SiR ^20A ₃ , where the organic radicals R ^16A -R ^19A may also be substituted by halogens or nitrogen and further CrC^-alkyl, C ₂ -C ₂₀ - alkenyl, C ₆ -C ₂₀ -aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical or SiR ^20A ₃ groups and two vicinal radicals _R i ⁶ A_ _R i ⁹ A _{or R} i ⁶ A _{and z may a|SQ j} -, _e j _Ojne d \ ₀ f _{orm a} 5. _or 6-membered ring and

the radicals R ^20A are each, independently of one another, hydrogen, C ₂ -C ₂₀ -alkenyl,

C ₆ -C ₂₀ -aryl or alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6 6--2200 ccaarrbboonn aattoommss iinn tthhee aarryyll rraaddiiccal and two radicals R ^20A may also be joined to form a 5- or 6-membered ring and

p is 0 when E ^6A -E ^9A is nitrogen and is 1 when E ^6A -E ^9A is carbon.

In particular, 0 or 1 of E ^6A -E ^9A is nitrogen and the remainder are carbon. A is particularly preferably 2-pyridyl, 6-methyl-2-pyridyl, 4-methyl-2-pyridyl, 5-methyl-2-pyridyl, 5-ethyl-2-pyridyl, 4,6-dimethyl-2-pyridyl, 3-pyridazyl, 4-pyrimidyl, 6-methyl-4-pyrimidyl, 2-pyrazinyl, 6-methyl- 2-pyrazinyl, 5-methyl-2-pyrazinyl, 3-methyl-2-pyrazinyl, 3-ethylpyrazinyl, 3,5,6-trimethyl- 2-pyrazinyl, 2-quinolyl, 4-methyl-2-quinolyl, 6-methyl-2-quinolyl, 7-methyl-2-quinolyl, 2-quinoxalyl or 3-methyl-2-quinoxalyl.

Owing to the ease of preparation, a preferred combination of Z and A is when Z is an unsubstituted or substituted 1 ,2-phenylene group and A is NR ^16A R ^17A , and also the combination in which Z is -CHR ^6A -, -CH ₂ -, -C(CH ₃ ) ₂ or -Si(CH ₃ ) ₂ - and A is unsubstituted or substituted 2-quinolyl or unsubstituted or substituted 2-pyridyl. Systems which do not have a bridge Z and in which k is 0 are also particularly simple to obtain. In this case, A is preferably unsubstituted or substituted 8- quinolyl. When k is 0, R ^2A is also preferably a C ₆ -C ₂₂ -aryl or an alkylaryl having from 1 to 10

carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, preferably C ₆ -C ₂₂ -aryl such as phenyl, naphthyl, biphenyl, anthracenyl or phenanthrenyl, where the aryl may also be substituted by N-, P-, O- or S-comprising substituents, C _r C ₂₂ -alkyl, C ₂ -C ₂₂ -alkenyl, halogens or haloalkyls or haloaryls having 1-10 carbon atoms.

The above-described preferred embodiments of the variables are also preferred in these preferred combinations.

M ^A is a metal selected from the group consisting of titanium in the oxidation state 3, vanadium, chromium, molybdenum and tungsten, preferably titanium in the oxidation state 3 and chromium. Particular preference is given to chromium in the oxidation states 2, 3 and 4, in particular 3. The metal complexes, in particular the chromium complexes, can be obtained in a simple manner by reacting the corresponding metal salts, e.g. metal chlorides, with the ligand anion (e.g. using a method analogous to the examples in DE 197 10615).

Among the suitable monocyclopentadienyl complexes, preference is given to those of the general formula Cp-Y _m M ^A X ^A _n (V), where the variables Cp, Y, A, m and M ^A are as defined above and their preferred embodiments are also preferred here and:

the radicals X ^A are each, independently of one another, fluorine, chlorine, bromine, iodine, hydrogen, d-C^-alkyl, C ₂ -C ₁₀ -alkenyl, C ₆ -C ₂₀ -aryl, alkylaryl having 1-10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, NR ^21A R ^22A , OR ^21A , SR ^21A , SO ₃ R ^21A , OC(O)R ^21A , CN, SCN, β-diketonate, CO, BF ₄ ^' , PF ₆ ^" or bulky noncoordinating anions or two radicals X ^A form a substituted or unsubstituted diene ligand, in particular a 1 ,3-diene ligand, and the radicals X ^A may be joined to one another,

_R ^21A _ _R ^22A _{are each} j _nc j _e p _enc j _en tiy _o f one another, hydrogen, CrC _∑ o-alkyI, C ₂ -C ₂₀ -alkenyl, C ₆ -C ₂₀ -aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, SiR ^23A ₃ , where the organic radicals R ^21A -R ^22A may also be substituted by halogens or nitrogen- and oxygen-containing groups and two radicals

_R ^21A _ _R ^22A _ma y _{a)so be} jQjned to form a five- or six-membered ring,

the radicals R ^23A are each, independently of one another, hydrogen, CrC _∑ o-alkyl, C ₂ -C ₂ o-alkenyl,

C ₆ -C ₂₀ -aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 ccaarrbboonn aattoommss iinn tthhee aarryyll rraadical and two radicals R ^23A may also be joined to form a five- or six-membered ring and

n is 1 , 2 or 3.

The embodiments and preferred embodiments of Cp, Y, Z, A, m and M ^A indicated above also apply individually and in combination to these preferred monocyclopentadienyl complexes.

The ligands X ^A result from, for example, the choice of the appropriate metal compounds used as starting materials for the synthesis of the monocyclopentadienyl complexes, but can also be varied subsequently. Possible ligands X ^A are, in particular, the halogens such as fluorine, chlorine, bromine or iodine, in particular chlorine. Alkyl radicals such as methyl, ethyl, propyl, butyl, vinyl, allyl, phenyl or benzyl are also advantageous ligands X ^A . As further ligands X ^A , mention may be made, purely by way of example and in no way exhaustively, of trifluoroacetate, BF ₄ ^' , PF ₆ ^' and weakly coordinating or noncoordinating anions (cf., for example, S. Strauss in Chem. Rev. 1993, 93, 927-942) such as B(C ₆ Fg) ₄ ^" .

Amides, alkoxides, sulfonates, carboxylates and β-diketonates are also particularly suitable ligands X ^A . Variation of the radicals R ^21A and R ^22A makes it possible, for example, to make fine adjustments in physical properties such as solubility. Possible carboorganic substituents R ^21A -R ^22A are, for example, the following: Ci-C ₂ o-alkyl which may be linear or branched, e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl, 5- to 7-membered cycloalkyl which may in turn bear a C ₆ -C ₁₀ -aryl group as substituent, e.g. cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclododecyl, C ₂ -C ₂ o-alkenyl which may be linear, cyclic or branched and in which the double bond may be internal or terminal, e.g. vinyl, 1-allyl, 2-allyl, 3-allyl, butenyl, pentenyl, hexenyl, cyclopentenyl, cyclohexenyl, cyclooctenyl or cyclooctadienyl, C ₆ -C ₂ o-aryl which may be substituted by further alkyl groups and/or N- or O-containing radicals, e.g. phenyl, naphthyl, biphenyl, anthranyl, o-, m-, p-methylphenyl, 2,3-, 2,4-, 2,5-, or 2,6-dimethylphenyl, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,5-, 2,4,6- or 3,4,5-trimethylphenyl, 2-methoxyphenyl, 2-N,N-dimethylaminophenyl, or arylalkyl, which may be substituted by further alkyl groups, e.g. benzyl, o-, m-, p-methylbenzyl, 1- or 2-ethylphenyl, where R ^21A may also be joined to R ^22A to form a 5- or 6-membered ring and the organic radicals R ^21A -R ^22A may also be substituted by halogens such as fluorine, chlorine or bromine. In organosilicon substituents SiR ^23A ₃ , the radicals R ^23A can be the same radicals described in more detail above for R ^21A -R ^22A , where two radicals R ^23A may also be joined to form a 5- or 6-membered ring, e.g. trimethylsilyl, triethylsilyl, butyldimethylsilyl, tributylsilyl, triallylsilyl, triphenylsilyl or dimethylphenylsilyl. Preference is given to using d-Cio-alkyl such as methyl, ethyl, n-propyl, n-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and also vinyl, allyl, benzyl and phenyl as radicals R ^21A and R ^22A . Some of these substituted ligands X are particularly preferably used because they are obtainable from cheap and readily available starting materials. Thus, a particularly preferred embodiment is that in which X ^A is dimethylamide, methoxide, ethoxide, isopropoxide, phenoxide, naphthoxide, triflate, p-toluenesulfonate, acetate or acetylacetonate.

The number n of the ligands X ^A depends on the oxidation state of the transition metal M ^A . The

number n can therefore not be given in general terms. The oxidation state of the transition metals M ^A in catalytically active complexes is usually known to those skilled in the art. Chromium, molybdenum and tungsten are very probably present in the oxidation state +3, vanadium in the oxidation state +3 or +4. However, it is also possible to use complexes whose oxidation state does not correspond to that of the active catalyst. Such complexes can then be appropriately reduced or oxidized by means of suitable activators. Preference is given to using chromium complexes in the oxidation state +3 and titanium complexes in the oxidation state 3.

Preferred monocyclopentadienyl complexes of this type are 1-(8-quinolyl)-3-phenylcyclopenta- dienylchromium(lll) dichloride, 1-(8-quinolyl)-3-(1-naphthyl)cyclopentadienylchromium(lll) dichloride, 1-(8-quinolyl)-3-(4-trifluoromethylphenyl)cyclopentadienylch romium(lll) dichloride, 1-(8-quinolyl)-3-(4-chlorophenyl)cyclopentadienylchromium(ll l) dichloride, 1-(8-quinolyl)-2-methyl- 3-phenylcyclopentadienylchromium(lll) dichloride, 1-(8-quinolyl)-2-methyl-3-(1-naphthyl)cyclo- pentadienylchromium(lll) dichloride, i-fδ-quinolyO^-methyl-S-^-trifluoromethylphenyOcyclopenta- dienylchromium(lll) dichloride, HS-quinolyO^-methyl-S-^-chlorophenyOcyclopentadienyl- chromium(lll) dichloride, 1-(8-quinolyl)-2-phenylindenylchromium(lll) dichloride, 1-(8-quinolyl)- 2-phenylbenzindenylchromium(lll) dichloride, 1-(8-(2-methylquinolyl))-2-methyl-3-phenylcyclo- pentadienylchromium(lll) dichloride, 1-(8-(2-methylquinolyl))-2-phenylindenylchromium(lll) dichloride, 1-(2-pyridylmethyl)-3-phenylcyclopentadienylchromium(lll) dichloride, 1-(2-pyridylmethyl)-2-methyl-3-phenylcyclopentadienylchromiu m(lll) dichloride,

1 -^-quinolylmethyO-S-phenylcyclopentadienylchromium dichloride, 1 -(2-pyridylethyl)-3-phenyl- cyclopentadienylchromium dichloride, 1-(2-pyridyl-1-methylethyl)-3-phenylcyclopentadienyl- chromium dichloride, i-^-pyridyl-i-phenylmethylJ-S-phenylcyclopentadienylchromium dichloride, 1-(2-pyridylmethyl)indenylchromium(lll) dichloride, 1-(2-quinolylmethyl)indenylchromium dichloride, 1-(2-pyridylethyl)indenylchromium dichloride, 1-(2-pyridyl-1- methylethyl)indenylchromium dichloride, 1-(2-pyridyl-1-phenylmethyl)indenylchromium dichloride, 5-[(2-pyridyl)methyl]-1 ,2,3,4-tetramethylcyclopentadienylchromium dichloride or 1-(8-(2- methylquinolyl))-2-methylbenzindenylchromium(lll) dichloride.

The preparation of such functional cyclopentadienyl ligands is known. Various synthetic routes are described, for example, by M. Enders et. al. In Chem. Ber. (1996), 129, 459-463, or P. Jutzi and U. Siemeling in J. Orgmet. Chem. (1995), 500, 175-185. The synthesis can be carried out by methods known per se, with preference being given to reacting the appropriately substituted, cyclic hydrocarbon anions with halides of titanium, vanadium or chromium. Examples of appropriate preparative methods are described, inter alia, in Journal of Organometallic Chemistry, 369 (1989), 359-370, and in EP-A-1212333.

The process of the invention can be advantageously employed when using hybrid catalysts, in order to change the comonomer content of the polymer component in a targeted manner. Particular preference is given to hybrid catalysts comprising catalyst components based on

monocyclopentadienyl complexes of the formula (I). For the purposes of the present invention, hybrid catalysts are catalyst systems which have at least two different types of active sites derived from at least two chemically different organic transition metal compounds. The different active sites can be active sites obtained from different transition metal coordination compounds of which one comprises a monocyclopentadienyl complex of the formula (I). However, it is also possible to use active sites which are derived from Ziegler-Natta catalysts or catalysts based on chromium, e.g. Phillips catalysts, and, for the purposes of the invention, are not organic transition metal complexes.

The hybrid catalysts are by definition suitable for producing bimodal or multimodal polymer products which comprise at least one relatively high molecular weight polymer component and a lower molecular weight polymer component. Here, the term bimodal describes a polymer which has two different polymer components, and the term multimodal describes a polymer which has more than two different polymer components. A polymer component is, logically, a polymer which has been produced by a specific type of active component in a polymerization catalyst comprising a plurality of components.

The hybrid catalysts used in the process of the invention can comprise mixtures of two or more different particulate catalyst solids. However, preference is given to using catalyst systems which comprise catalyst solids in which all types of active sites are in each case present on one catalyst particle. Particular preference is given to using a plurality of catalyst components which have together been fixed on a support.

Hybrid catalysts in which at least two of the constituents resulting from the different transition metal components in the hybrid catalysts differ in their comonomer incorporation behavior are preferably used in the process of the invention. These lead to polymer products in which the comonomer content of the higher molecular weight polymer component differs from that of the lower molecular weight polymer component, i.e. the catalyst components display different comonomer incorporation behavior. For the purposes of the present patent application, a different comonomer incorporation behavior is present when the comonomer content of the different polymer components differs by at least 30%. The comonomer content of the polymer components preferably differs by at least 50%, more preferably by a factor of 2, more preferably by a factor of 10, particularly preferably by a factor of 100.

In a preferred variant, the higher molecular weight polymer component is that having the higher comonomer content. This higher molecular weight polymer component is particularly preferably formed from the catalyst component comprising the monocyclopentadienyl complex of the formula (I). In one embodiment, the lower molecular weight polymer component has a comonomer content of 0-1.5 mol%, preferably 0-0.8 mol%, particularly preferably 0-0.3 mol%. In a further embodiment, the higher molecular weight polymer component has a comonomer content

of from 0 to 15 mol%, preferably from 0.01 to 10 mol%, particularly preferably from 0.3 to 3 mol%.

The lower molecular weight polymer component preferably has a mean molar mass M _w of from 10 000 to 100 000 g/mol, more preferably from 20 000 to 80 000 g/mol, particularly preferably from 30 000 to 70 000 g/mol. The higher molecular weight polymer component preferably has a mean molar mass M _w of from 100 000 to 2 000 000 g/mol, more preferably from 150 000 to 1 000 000 g/mol, particularly preferably 200 000-800 000 g/mol. Depending on product requirements, different combinations of proportions of the high molecular weight component and low molecular weight component and molar masses of the components are selected. The ratio of higher molecular weight component to lower molecular weight component is preferably from 5 to 95% by weight, more preferably from 10 to 90% by weight, particularly preferably from 20 to 80% by weight, in each case based on the sum of the higher molecular weight component and the low molecular weight component. It may be emphasized that further polymer components in addition to a relatively high molecular weight component and a low molecular weight component may be present in the polymer product.

To independently regulate the comonomer content of the higher molecular weight polymer component to the lower molecular weight polymer component, the catalyst components preferably have a different responsiveness to the modifiers used according to the invention. To independently regulate the molar masses of the higher molecular weight polymer component to the lower molecular weight polymer component, the catalyst components preferably also have a different responsiveness to molar mass regulators such as hydrogen.

As an alternative to or preferably together with a catalyst component comprising a monocyclopentadienyl complex of the formula (I), further catalysts can be present in the polymerization. Particular preference is here given to ones of the general formulae (Via) to (VIc)

where the substituents and indices have the following meanings:

M 1A is titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum or tungsten or an element of group 3 of the Periodic Table and the lanthanides,

the radicals X ^A are identical or different and are each, independently of one another, fluorine, chlorine, bromine, iodine, hydrogen, C-i-Cio-alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₁₀ -alkenyl, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, -OR ^6λ or -NR ^6A R ^7A , or two radicals X ^A are joined to one another and form, for example, a substituted or unsubstituted diene ligand, in particular a 1 ,3-diene ligand, or a biaryloxy group or a ligand of the following formula

where

Q ^1A and Q ^2A are each O, NR ,6' A

CR ^6A R ^7A or S and Q ^1A and Q ^2A are

1A bound to M

Y ^A is C or S and

is OR ^6A , SR ^6A , NR ^6A R ^7A , PR ^6A R ^7A , hydrogen, C,-C ₁₀ -alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₁₀ - alkenyl, C ₆ -C ₄ o-aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical or -SiR ^8A ₃ ,

E ^1A to E ^5A are each carbon or not more than one E ^1A to E ^5A is phosphorus or nitrogen, preferably carbon,

is 1 , 2 or 3 and is such that, depending on the valence of M ^1A , the complex of the general formula (Via), (VIb), (VIc) or (Id) is uncharged,

R ^1A to R ^5A are each, independently of one another, hydrogen, d-C ₂₂ -alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl which may in turn bear C _r C ₁₀ -alkyl groups as substituents, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄ o-aryl, -NR ^8A ₂ , -N(SiR ^8A ₃ ) ₂ , -OR ^8A , -OSiR ^8A ₃ , -SiR ^8A ₃ , where the radicals R ^1A to R ^5A may also be substituted by halogen and/or two radicals R ^1A to R ^5A , in particular adjacent radicals, may be joined so that together with the atoms connecting them they form a preferably five-, six- or seven-membered ring or a preferably five-, six- or seven-membered heterocycle which comprises at least one atom from the group consisting of N, P, O and S,

R ^6A and R ^7A are each, independently of one another, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical or -SiR ^8A ₃ , where the radicals R ^6A and R ^7A may also be substituted by halogens and/or two radicals R ^6A and R ^7A may also be joined to form a five-,

six- or seven-membered ring,

the radicals R ^8A are identical or different and are each Ci-Cio-alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, Crdo-alkoxy or C ₆ -C ₁₀ -aryloxy, where the radicals R ^8A may also be substituted by halogens and/or two radicals R ^8A may also be joined to form a five-, six- or seven-membered ring, and

R ^9A to R ^13A are each, independently of one another, hydrogen, Ci-C ₂₂ -alkyl, 5- to

7-membered cycloalkyl or cycloalkenyl which may in turn bear d-do-alkyl groups as substituents, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄ o-aryl, arylalkyl having from 1 to 16 carbon atoms in the alkyl radical and 6-21 carbon atoms in the aryl radical, -NR ^14A ₂ , -N(SiR ^14A ₃ ) ₂ , -OR ^14A , -OSiR ^14A ₃ or -SiR ^14A ₃ , where the radicals R ^1A to R ^5A may also be substituted by halogen and/or two radicals R ^1A to R ^5A , in particular adjacent radicals, may be joined so that together with the atoms connecting them they form a preferably five-, six- or seven-membered ring or a preferably five-, six- or seven-membered heterocycle which comprises at least one atom from the group consisting of N, P, O and S, where

the radicals R ^14A are identical or different and are each d-do-alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄ o-aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, C ₁ -C _1O -BIkOXy or C ₆ -C ₁₀ -aryloxy, where the organic radicals R ^14A may also be substituted by halogens and/or two radicals R ^14A may also be joined to form a five-, six- or seven-membered ring, and

E ^6A to E ^10A are each carbon or not more than one E ^6A to E ^10A is phosphorus or nitrogen, preferably carbon,

or the radicals R ^4A and Z ^1A together form an -R ^15A _V -A ^1A - group in which

_R 15A

-BR ^16A - , -(BNR ^16A R ^17A )- , -AIR ^16A - , -Ge- , -Sn- , -O- , -S- ,

-SO- , -SO ₂ - , -NR ^16A - , -CO- , -PR ^16A - Oder -(POR ^16A )- ist,

where

R ^16A to R ^21A are identical or different and are each a hydrogen atom, a halogen atom, a trimethylsilyl group, 5- to 7-membered cycloalkyl or cycloalkenyl,

C ₂ -C ₂ 2-alkenyl, C ₆ -C ₄ o-aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, CrC^-alkoxy or C ₆ -Cio-aryloxy, where the organic radicals R ^16A -R ^21A may also be substituted by halogens and/or two radicals R ^16A -R ^21A may also be joined to form a five-, six- or seven-membered ring, and

M ² * to M ^4A are each silicon, germanium or tin, preferably silicon,

A ^1A is -O- , -S- , -NR ^22A - , -PR ^22A - , -OR ^22A , -NR ^22A ₂ , -PR ^22A ₂

or an unsubstituted, substituted or fused, heterocyclic ring system, where

the radicals R ^22A are each, independently of one another, C-i-Cio-alkyl, 5- to 7-membered cycloalkyl, cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl or arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical or Si(R ^23A ) ₃ , where the organic radicals R ^22A may also be substituted by halogens and/or two radicals R ^22A may also be joined to form a five-, six- or seven-membered ring,

R ^23A is hydrogen, Ci-C ₁₀ -alkyl, 5- to 7-membered cycloalkyl, cycloalkenyl, C ₂ -C ₂₂ -

alkenyl, C ₆ -C ₄ o-aryl or arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, where the organic radicals R ^23A may also be substituted by halogens and/or two radicals R ^23A may also be joined to form a five-, six- or seven-membered ring, and

v is 1 or when A ^1A is an unsubstituted, substituted or fused, heterocyclic ring system is 1 or 0.

Among the complexes of the formula (Via), particular preference is given to those in which

M ^1A is titanium, zirconium or hafnium,

the radicals X ^A are identical or different and are each, independently of one another, chlorine,

C _r C ₄ -alkyl, phenyl, alkoxy or aryloxy, a carboxylate of the formula -0-C(O)- R ^6A or a carbamate of the formula -0-C(O)-N R ^6A R ^7A ,

t is 1 or 2, preferably 2,

_R I ^A _{t0 R} 5 ^A _{are each nydrO} g _{en or} c _r c ₆ -alkyl or two adjacent radicals R ^1A to R ^5A together with the atoms connecting them form a substituted or unsubstituted five-, six- or seven-membered ring and in particular a substituted or unsubstituted six- mem bered ring and

R ^6A and R ^7A are each C _r Cio-alkyl, C ₆ -C ₄₀ -aryl or arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical.

The preparation of such compounds (Via) and particularly preferred embodiments of the compounds (Via) are described, for example, in US-A 5 527 752.

Among the unbridged metallocene complexes of the formula (VIb), preference is given to those in which

M ^1A is zirconium, hafnium or chromium,

X ^A is fluorine, chlorine, C-i-C _A -alkyl or benzyl, or two radicals X ^A form a substituted or unsubstituted diene ligand,

t is 0 in the case of chromium, otherwise 1 or 2, preferably 2,

R ^1A to R ^5A are each hydrogen, d-Cβ-alkyl, C ₆ -C ₁₀ -aryl, -NR ^8A ₂ , -OSiR ^8A ₃ or -Si(R ^8A ) ₃ ,

_R ^9A _{t0 R} ^i3A _{are each hydrogen} c-C _β -alkyl, C ₆ -C ₁₀ -aryl, -NR ^14A ₂ , -OSiR ^14A ₃ or -Si(R ^14A ) ₃ and

R ^8A and R ^14A are identical or different and are each d-do-alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₆ -C ₄ o-aryl, d-do-alkoxy or C ₆ -C ₁₀ -aryloxy, where the radicals R ^8A and R ^14A may also be substituted by halogens and/or two radicals R ^8A or R ^14A may also be joined to form a five-, six- or seven- mem bered ring,

or two radicals R ^1A to R ^5A and/or R ^9A to R ^13A together with the C ₅ ring form an indenyl, fluorenyl or substituted indenyl or fluorenyl system.

The complexes of the formula (VIb) in which the cyclopentadienyl radicals are identical, for example bis(cyclopentadienyl)chromium or bis(indenyl)chromium, are particularly useful.

Further examples of particularly useful complexes of the formula (VIb) are those in which

M ^1A is hafnium,

X ^A is fluorine, chlorine, d-d-alky! or benzyl or two radicals X ^A form a substituted or unsubstituted diene ligand,

t is 2,

R ^1A to R ^5A are each hydrogen, d-C ₈ -alkyl or C ₆ -C ₁₀ -aryl,

_R ^9A _{t0 R} ^i3A _{are each nydrO} g _eri| d-C _β -alkyl or C ₆ -C ₁₀ -aryl,

R ^8A and R ^14A are identical or different and are each d-C ₁₀ -alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₆ -C ₄₀ -aryl, d-C ₁₀ -alkoxy or C ₆ -C ₁₀ -aryloxy, where the radicals R ^8A and R ^14A may also be substituted by halogens and/or two radicals R ^8A or R ^14A may also be joined to form a five-, six- or seven-membered ring,

or two radicals R ^1A to R ^5A and/or R ^9A to R ^13A together with the C ₅ ring form an indenyl, fluorenyl or substituted indenyl or fluorenyl system.

A further preferred group of complexes (VIb) are those in which:

M ^1A is zirconium,

X ^A is fluorine, chlorine, Ci-C ₄ -alkyl or benzyl or two radicals X ^A form a substituted or unsubstituted diene ligand,

t is 1 or 2, preferably 2,

_R I ^A _{tQ R} ^5A _{are each n} y _drO g _en| d-C _β -alkyl, C ₆ -C ₁₀ -aryl, -OSiR ^8A ₃ ,

_R ^9A _{t0 R} ^i3A _{are each n} y _drO g _en| d-C _β -alkyl or C ₆ -C ₁₀ -aryl or -OSiR ^14A ₃ and

R ^8A and R ^14A are identical or different and are each CrCm-alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₆ -Ci ₅ -aryl, Ci-Ci ₀ -alkoxy or C ₆ -C ₁₀ -aryloxy, where the organic radicals R ^8A and R ^14A may also be substituted by halogens and/or two radicals R ^8A or R ^14A may also be joined to form a five-, six- or seven-membered ring,

or two radicals R ^1A to R ^5A and/or R ^9A to R ^13A together with the C ₅ ring form an indenyl, fluorenyl or substituted indenyl or fluorenyl system.

The preparation of such systems and preferred embodiments are disclosed, for example, in FI-A-960437.

Catalyst components based on the unbridged metallocenes mentioned are particularly useful for providing the relatively high molecular weight polymer component. They are, in particular, also suitable for providing the polymer component which is richer in comonomer. These catalyst components are particularly preferably used for producing a comonomer-rich, relatively high molecular weight polymer component.

Particularly useful complexes of the formula (VIc) are those in which

R ^16A R ^16A R ^18A

R ^15A is Si or

17A _R 17A _R 19A

M ^1A is titanium, zirconium or hafnium, in particular zirconium or hafnium,

the radicals X ^A are identical or different and are each chlorine, Ci-C ₄ -alkyl, benzyl, phenyl or

C ₇ -Ci ₅ -alkylaryloxy.

As complexes of the formula (VIc), preference is also given to using bridged bisindenyl complexes in the rac or pseudo-rac form, with the pseudo-rac form being complexes in which the two indenyl ligands are in the rac arrangement relative to one another when all other substituents of the complex are disregarded.

Such complexes can be synthesized by methods known per se, with preference being given to reacting the appropriately substituted, cyclic hydrocarbon anions with halides of titanium, zirconium, hafnium, vanadium, niobium, tantalum or chromium. Examples of appropriate preparative methods are described, inter alia, in Journal of Organometallic Chemistry, 369 (1989), 359-370.

Further suitable compounds are organic transition metal complexes which comprise no cyclopentadienyl units, hereinafter referred to as Cp-free complexes. Useful Cp-free complexes are complexes of the general formula (VII)

where M 1 B is titanium, zirconium or hafnium,

R ^1B to R ^6B are each, independently of one another, d-C ₂₂ -alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl which may in turn bear d-Cio-alkyl groups as substituents, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 16 carbon atoms in the alkyl radical and from 6 to 21 carbon atoms in the aryl radical or -SiR ^9B ₃ , where the radicals R -R may also be substituted by halogens and/or two radicals R -R , in particular vicinal radicals, may also be joined to form a five-, six- or seven-membered ring and/or two vicinal radicals R ^1B -R ^6B may be joined to form a five-, six- or seven-membered heterocycle which comprises at least one atom from the group consisting of N, P, O and S,

the radicals X ^1B are each, independently of one another, fluorine, chlorine, bromine, iodine, hydrogen, C _r Ci ₀ -alkyl, C ₂ -C ₁₀ -alkenyl, C ₆ -C ₁₅ -aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, -OR ^7B , -NR ^7B R ^8B , -O-C(O)-R ^7B or -0-C(O)-N R ^7B R ^8B , and the radicals X ^1B may

optionally be joined to one another,

A ^1B is -O- , -OR ^7B - , -NR ^7B - or -NR ^7B R ^8B - ,

m is 1 or 2,

n is 1 , 2 or 3 and is such that, depending on the valence of M ^1A , the metallocene complex of the general formula (VII) is uncharged,

o is 1 when NR ^1B together with the adjacent carbon forms an imine or is 2 when NR ^1B carries a negative charge,

where

R ^7B and R ^8B are each C ₁ -C ₁₀ -SlKyI ₁ 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄ o-aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical or -SiR ^9B , where the organic radicals R ^7B and R ^8B may also be substituted by halogens and/or two radicals R ^7B and R ^8B may also be joined to form a five- , six- or seven-membered ring, and

the radicals R are identical or different and can each be CrC^-alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl, C _r C ₄ -alkoxy or C ₆ -C ₁₀ -aryloxy, where the organic radicals R ^9B may also be substituted by halogens and/or two radicals R ^9B may also be joined to form a five-, six- or seven-membered ring.

Preferred organic transition metal complexes of the general formula (VII) are iminophenoxide complexes in which A ^1B is -O- and o is 1 , with the ligands being prepared, for example, from substituted or unsubstituted salicylaldehydes and primary amines, in particular substituted or unsubstituted arylamines. The preparation of such compounds is described, for example, in EP-A 1013674.

Further suitable complexes are Cp-free complexes of the general formula (VIII):

where

M 1C is titanium, zirconium or hafnium,

,5C R ^1c to R are each, independently of one another, hydrogen, Ci-C ₂₂ -alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 16 carbon atoms in the alkyl radical and from 6 to 21 carbon atoms in the aryl radical or -SiR ^8C ₃ , where the organic radicals R ^1C to R ^5C may also be substituted by halogens and/or two radicals R ^1C to R ^5C , in particular adjacent radicals, may also be joined to form a five-, six- or seven-mem bered ring and/or two vicinal radicals R ^1C to R ^5C may be joined to form a five-, six- or seven-mem bered heterocycle which comprises at least one atom from the group consisting of N, P, O and S,

the radicals X ^1C are each, independently of one another, fluorine, chlorine, bromine, iodine, hydrogen, C ₁ -C ₁ ( _T aIkVl ₁ 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄ o-aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the B a ariyyli r IaeIdUiic(JacIli,, -—O <~/R 6 r\' C - -NNRR ^66CC RR ^77CC ,, --OO--CC((OO))--RR ^66CC oorr --OO--CC((O)-NR ^6C R ^7C and the radicals X ^1C may optionally be joined to one another,

v 1C is -CR ^6C R ^7C - or -CR ^6C =

m is 1 or 2,

«1A is 1 , 2 or 3 and is such that, depending on the valence of M ₁ the metallocene complex of the general formula (VII) is uncharged,

is 0 or 1 ,

where

R ^6C and R ^7C are each d-Cio-alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical or -SiR ^8C , where the organic radicals R and R may also be substituted by halogens and/or two radicals R ^6C and R ^7C may also be joined to form a five-, six- or seven-membered ring and

8C the radicals R' are identical or different and are each Ci-Ci _O -alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the

-,8C aryl radical, Ci-C ₄ -alkoxy or C ₆ -C ₁₀ -aryIoxy, where the organic radicals R ⁸ may also be substituted by halogens and/or two radicals R ^8C may also be joined to form a five-, six- or seven-membered ring.

Preferred organic transition metal complexes of the general formula (VIII) are complexes in which oo iiss 11 ,, AA ^11CC iiss --CCRR ^66CC RR ^77CC -- aanndd RR ^11CC iiss CC ₆₆ --CC ₄₄₀₀ --aarryyll.. TThhee preparation of such compounds is described, for example, in WO 02/046249 and WO 03/040201.

Further suitable complexes are Cp-free complexes having at least one ligand of the general formulae (IXa) to (IXe),

(IXb) (IXd) (IXe)

where the transition metal is selected from among the elements Ti, Zr, Hf, Sc, V, Nb, Ta, Cr, Mo, W, Fe, Co, Ni, Pd, Pt and the elements of the rare earth metals. Preference is given to compounds having nickel, iron, cobalt or palladium as central metal.

E ^1D is an element of group 15 of the Periodic Table of the Elements, preferably N or P, with particular preference being given to N. The two or three atoms E ^1D in a molecule can be identical or different. The elements E ^2D in the formula (IXe) are each, independently of one another, carbon, nitrogen or phosphorus, in particular carbon.

The radicals R ^1D to R ^25D , which may be identical or different within a ligand system (IXa) to (IXe), are as follows:

R ^1D and R ^4D are each, independently of one another, C _r C ₁₀ -alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄ o-aryl or arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, where the organic radicals R ^1D and R ^4D may also be substituted by halogens, with hydrocarbon radicals in which the carbon atom adjacent to the element E ^1D is joined to at least two carbon atoms being preferred,

R ^2D and R ^3D are each, independently of one another, hydrogen, Ci-C ₁₀ -alkyl, 5- to

7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl or arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, where the organic radicals R ^2D and R ^3D may also be substituted by halogens and R ^2D and R ^3D may together also form a ring system in which one or more heteroatoms may also be present,

_R ^5D _{t0 R} ^9D _{gre each} i _nc | _e p _enc j _en tiy _o f _one another, hydrogen, d-do-alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl or arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, where the organic radicals R ^5D to R ^9D may also be substituted by halogens and R ^6D and R ^5D or R ^8D and R ^9D or two radicals R ^7D may together form a ring system,

R ^10D and R ^14D are each, independently of one another, d-do-alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl or arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, where the organic radicals R ^10D and R ^14D may also be substituted by halogens,

R ^11D , R ^12D , R ^12D' and R ^13D are each, independently of one another, hydrogen, d-do-alkyl, 5- to

7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl or arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, where the organic radicals R ^11D ,

R ^12D , R ^12D and R ^13D may also be substituted by halogens and two or more geminal or vicinal radicals R ^11D , R ^12D , R ^12D and R ^13D may together form a ring system,

R ^15D to R ^18D and R ^20D to R ^24D are each, independently of one another, hydrogen, d-do-alkyl,

5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical or -SiR ^26D ₃ , where the organic radicals R ^15D -R ^18D and R ^20D -R ^24D may also be substituted by halogens and two vicinal radicals R ^15D -R ^18D and R ^20D -R ^24D may also be joined to form a five- or six-mem bered ring,

R ^19D and R ^25D are each, independently of one another, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical or -NR ^26D ₂ , where the organic radicals R ^19D and R ^25D

may also be substituted by halogens or a group comprising Si, N, P, O or S,

R ^20D to R ^24D are each, independently of one another, hydrogen, C _r C ₁₀ -alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, -NR ^26D ₂ , -SiR ^26D ₃ , where the organic radicals R ^20D to R ^25D may also be substituted by halogens and/or two geminal or vicinal radicals R ^20D to R ^25D may also be joined to form a five-, six- or seven-mem bered ring and/or two geminal or vicinal radicals R ^20D to R ^25D may be joined to form a five-, six- or seven-membered heterocycle which comprises at least one atom from the group consisting of N, P, O and S,

26D the radicals R are each, independently of one another, hydrogen, C _r C ₂ o-alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₀ -alkenyl, C ₆ -C ₄₀ -aryl or arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and 6-20

26D carbon atoms in the aryl radical and two radicals R may also be joined to form a five- or six-membered ring,

is 0 when E ^2D is nitrogen or phosphorus and is 1 when E ^2D is carbon,

the indices v are each, independently of one another, 1 or 2, so that when v is 1 , the bond between the carbon which then bears one radical and the adjacent element E ^1D is a double bond and when v is 2 the bond between the carbon which then bears two radicals and the adjacent element E ^1D is a single bond,

is 0 or 1 , with the complex of the formula (IXc) being negatively charged when x is 0, and

is an integer from 1 to 4, preferably 2 or 3.

Particularly useful complexes are Cp-free complexes having Fe, Co, Ni, Pd or Pt as central metal and ligands of the formula (IXa).

Catalyst components based on the abovementioned late transition metal complexes are particularly useful for providing the lower molecular weight polymer component. They are also particularly useful for providing the polymer component which is relatively low in comonomer, in particular the essentially comonomer-free polymer component. These catalyst components are

particularly preferably used for producing a low-comonomer, relatively low molecular weight polymer component.

Preferred organic transition metal complexes for preparing hybrid catalyst systems are complexes of the ligands (IXe) with transition metals Fe, Co or Ni and in particular those of the general formula (X)

where

the atoms E ^2D are each, independently of one another, carbon, nitrogen or phosphorus, in particular carbon,

R ^20D and R ^24D are each, independently of one another, hydrogen, C ₁ -C _2O -BlKyI, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, -NR ^26D ₂ or -SiR ^26D ₃ , where the organic radicals R ^20D and R ^24D may also be substituted by halogens,

R ^21D to R ^23D are each, independently of one another, hydrogen, CrC _∑ o-alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, halogen, -NR ^26D ₂ or -SiR ^26D ₃ , where the organic radicals R ^21D to R ^23D may also be substituted by halogens and/or two vicinal radicals R ^21D to R ^23D may also be joined to form a five-, six- or seven-mem bered ring and/or two vicinal radicals R ^21D to R ^23D are joined to form a five-, six- or seven-mem bered heterocycle which comprises at least one atom from the group consisting of N, P, O and S,

is 0 when E ^2D is nitrogen or phosphorus and is 1 when E ^2D is carbon,

_R 27D _{to R} 30D are each, independently of one another, Ci-C ₂₀ -alkyl, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄ o-aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, halogen, -NR ^26D ₂ , -OR ^26D or -SiR ^26D ₃ , where the organic radicals R ^27D to R ^30D may also be substituted by halogens and/or two vicinal radicals R ^27D to R ^30D may also be joined to form a five-, six- or seven-mem bered ring and/or two vicinal radicals R ^27D to R ^30D are joined to form a five-, six- or seven-membered heterocycle which comprises at least one atom from the group consisting of N, P, O and S,

_R 31D _{to R} 36D are each, independently of one another, hydrogen, CrC _∑ o-alkyI, 5- to 7-membered cycloalkyl or cycloalkenyl, C ₂ -C ₂₂ -alkenyl, C ₆ -C ₄₀ -aryl, arylalkyl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, halogen, -NR ^26D ₂ , -OR ^26D or -SiR ^26D ₃ , where the organic radicals R ^31D to R ^36D may also be substituted by halogens and/or two vicinal radicals R ^31D to R ^36D may also be joined to form a five-, six- or seven-membered ring and/or two vicinal radicals R ^31D to R ^36D are joined to form a five-, six- or seven-membered heterocycle which comprises at least one atom from the group consisting of N, P, O and S,

the indices v are each, independently of one another, 0 or 1 ,

the radicals X ^D are each, independently of one another, fluorine, chlorine, bromine, iodine, hydrogen, Ci-Ci _O -alkyl, C ₂ -C ₁₀ -alkenyl, C ₆ -C ₄ o-aryl, arylalkyl having 1-10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, -NR ^26D ₂ , -OR ^26D , -SR ^26D , -SO ₃ R ²⁶⁰ , -O-C(O)-R ^26D , -CN, -SCN, β-diketonate, CO, BF ₄ ^" , PF ₆ ^" or a bulky noncoordinating anion and the radicals X ^D may optionally be joined to one another,

the radicals R 26D are each, independently of one another, hydrogen, C _r C ₂ o-alkyl, C ₂ -C ₂ o-alkenyl, C ₆ -C ₂₀ -aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6-20 carbon atoms in the aryl radical, where the organic

,26D radicals R may also be substituted by halogens or nitrogen- and oxygen-

26D comprising groups and two radicals R may also be joined to form a five- or six-membered ring,

is 1 , 2, 3 or 4, in particular 2 or 3,

D is an uncharged donor and

t is from 0 to 4, in particular 0, 1 or 2.

Some of the organic transition metal complexes mentioned have little polymerization activity on their own and are therefore brought into contact with an activating compound in order to be able to display good polymerization activity. For this reason, the catalyst system preferably comprises, as further component, one or more activating compounds, hereinafter also referred to as activators or cocatalysts. Depending on the type of catalyst components, one or more activators are advantageous here. For example, the same activator or activator mixture or different cocatalysts can be used for activation. It is advantageous to use the same activator for at least two, particularly advantageously all, catalyst components.

Suitable activators are, for example, compounds such as an aluminoxane, a strong uncharged Lewis acid, an ionic compound having a Lewis-acid cation or an ionic compound having a Brόnsted acid as cation. Suitable activators for the types of catalyst mentioned are generally known.

The amount of the activating compounds to be used depends on the type of activator. In general, the molar ratio of metal complex A) to activating compound C) can be from 1 :0.1 to 1 :10 000, preferably from 1 :1 to 1 :2000.

Preference is given to using at least one aluminoxane as activating compound for carrying out the process of the invention. As aluminoxanes, it is possible to use, for example, the compounds described in WO 00/31090. A particularly useful aluminoxane is methylaluminoxane (MAO).

As strong, uncharged Lewis acids, preference is given to compounds of the general formula (Xl)

_M 2D _χ 1D _χ 2D _χ 3D _(χ|)

where

M ^2D is an element of group 13 of the Periodic Table of the Elements, in particular B, Al or Ga, preferably B,

X ^1D , X ^2D and X ^3D are each hydrogen, Ci-Cio-alkyl, C ₆ -C ₁₅ -aryl, alkylaryl, arylalkyl, haloalkyl or haloaryl each having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical or fluorine, chlorine, bromine or iodine, in particular haloaryls, preferably pentafluorophenyl. Examples of strong, uncharged Lewis acids are given in WO 00/31090.

Suitable ionic compounds having Lewis-acid cations include salt-like compounds of the cation of the general formula (XIII)

[((M ^3D ) ^a+ )QiQ ₂ -Q _z ] ^d+ (XIII)

where

M ^3D is an element of groups 1 to 16 of the Periodic Table of the Elements,

Qi to Q ₂ are singly negatively charged groups such as Ci-C ₂₈ -alkyl, C ₆ -C ₁₅ -aryl, alkylaryl, arylalkyl, haloalkyl, haloaryl each having from 6 to 20 carbon atoms in the aryl radical and from 1 to 28 carbon atoms in the alkyl radical, C ₃ -C ₁₀ -cycloalkyl which may optionally bear C^-C^-alkyl groups as substituents, halogen, d-Cas-alkoxy, C ₆ -Ci ₅ -aryloxy, silyl or mercaptyl groups,

a is an integer from 1 to 6 and

z is an integer from 0 to 5,

d corresponds to the difference a-z, but d is greater than or equal to 1.

Particularly useful cations are carbonium cations, oxonium cations and sulfonium cations and also cationic organic transition metal complexes. Particular mention may be made of the triphenylmethyl cation, the silver cation and the 1 ,1'-dimethylferrocenyl cation. They preferably have noncoordinating counterions, in particular boron compounds as are also mentioned in WO 91/09882, preferably tetrakis(pentafluorophenyl)borate.

It is also possible to use mixtures of all the abovementioned activators. Preferred mixtures comprise aluminoxanes, in particular methylaluminoxane, and an ionic compound, in particular one which comprises the tetrakis(pentafluorophenyl)borate anion, and/or a strong uncharged Lewis acid, in particular tris(pentafluorophenyl)borane or a boroxin.

Preference is given to using an aluminoxane as joint activator for the preferred catalysts mentioned. Furthermore, the combination of salt-like compounds of the cation of the general formula (XIII), in particular N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N-dimethyl- cyclohexylammonium tetrakis(pentafluorophenyl)borate, N,N-dimethylbenzylammonium tetrakis(pentafluorophenyl)borate or trityl tetrakispentafluorophenylborate, is preferred as activator for hafnocenes, in particular in combination with an aluminoxane as activator for the iron complex. Further particularly useful joint activators are the reaction products of aluminum compounds of the

formula (XIII) with perfluorinated alcohols and phenols.

The catalysts, in particular hybrid catalysts, can be used in supported or unsupported form, with the supported form being preferred, especially for use in gas-phase polymerization reactors. When a hybrid catalyst is used, particular preference is given to the various catalysts being cosupported on only one support, since the process of the invention is particularly advantageous in this case. As an alternative, the catalysts can also each be supported separately and used in this form.

As supports, preference is given to using finely divided supports which can be any organic or inorganic solids. As inorganic support materials, preference is given to using silica gel, magnesium chloride, aluminum oxide, mesoporous materials, aluminosilicates and hydrotalcites. Particular preference is given to using silica gel since particles whose size and structure make them suitable as supports for olefin polymerization can be produced from this material. Spray- dried silica gels which are spherical agglomerates of smaller granular particles, known as primary particles, have been found to be particularly useful.

The supports used preferably have a specific surface area in the range from 10 to 1000 m ² /g, a pore volume in the range from 0.1 to 5 ml/g and a mean particle diameter of from 1 to 500 μm. Preference is given to supports having a specific surface area in the range from 50 to 700 m ² /g, a pore volume in the range from 0.4 to 3.5 ml/g and a mean particle diameter in the range from 5 to 350 μm. Particular preference is given to supports having a specific surface area in the range from 200 to 550 m ² /g, a pore volume in the range from 0.5 to 3.0 ml/g and a mean particle diameter of from 10 to 150 μm, in particular 30 to 120 μm.

The supports can be subjected to a thermal treatment, e.g. to remove adsorbed water, before use. Such a drying treatment is generally carried out at temperatures in the range from 80 to 300 ⁰ C, preferably from 100 to 200°C, with drying at from 100 to 200 ⁰ C preferably being carried out under reduced pressure and/or under a blanket of inert gas (e.g. nitrogen). As an alternative, inorganic supports can be calcined at temperatures of from 200 to 1000 ⁰ C to produce the desired structure of the solid and/or to set the desired OH concentration on the surface.

The combinations of the preferred embodiments of the activators with the preferred embodiments for the catalyst components are particularly preferred.

In a preferred embodiment of the preparation of a supported catalyst, at least one iron complex is brought into contact with an activator and subsequently mixed with the dehydrated or passivated support. The further transition metal compound, preferably a hafnocene or zirconocene, is likewise brought into contact with at least one activator in a suitable solvent, preferably giving a soluble reaction product, an adduct or a mixture. The preparation obtained in this way is then

mixed with the immobilized iron complex, which is used directly or after the solvent has been separated off, and the solvent is completely or partly removed. The resulting supported catalyst system is preferably dried to ensure that all or most of the solvent is removed from the pores of the support material. The supported catalyst is preferably obtained as a free-flowing powder. Examples of the industrial implementation of the above process are described in WO 96/00243, WO 98/40419 or WO 00/05277. In a further preferred embodiment, the activator is applied to the support first and this supported compound is subsequently brought into contact with the appropriate transition metal compounds.

The catalyst may additionally comprise, as further component, a metal compound of the general formula (XX),

M ^G (R ^1G ) _r G (R ^2G ) _s G (R ^3G ) _t G (XX)

where

M ^G is Li, Na, K, Be, Mg, Ca, Sr, Ba, boron, aluminum, gallium, indium, thallium, zinc, in particular Li, Na, K, Mg, boron, aluminum or Zn,

R ^1G is hydrogen, Ci-Ci _O -alkyl, C ₆ -Ci ₅ -aryl, alkylaryl or arylalkyl each having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical,

R ^2G and R ^3G are each hydrogen, halogen, d-do-alkyl, C ₆ -C ₁₅ -aryl, alkylaryl, arylalkyl or alkoxy each having from 1 to 20 carbon atoms in the alkyl radical and from 6 to 20 carbon atoms in the aryl radical, or alkoxy with d-do-alkyl or C ₆ -Ci ₅ -aryl,

r ^G is an integer from 1 to 3 and

s ^G and t ^G are integers from 0 to 2, with the sum r ^G + s ^G + t ^G corresponding to the valence of M ^G ,

where the component (E) is usually not identical to the component (C). It is also possible to use mixtures of various metal compounds of the formula (XX).

Among the metal compounds of the general formula (XX), preference is given to those in which

M ^G is lithium, magnesium, boron or aluminum and

>1 G is Ci-C ₂ o-alkyl.

Particularly preferred metal compounds of the formula (XX) are methyllithium, ethyllithium, n-butyllithium, methylmagnesium chloride, methylmagnesium bromide, ethylmagnesium chloride, ethylmagnesium bromide, butylmagnesium chloride, dimethylmagnesium, diethylmagnesium, dibutylmagnesium, n-butyl-n-octylmagnesium, n-butyl-n-heptylmagnesium, in particular n-butyl- n-octylmagnesium, tri-n-hexylaluminum, triisobutylaluminum, tri-n-butylaluminum, triethylaluminum, dimethylaluminum chloride, dimethylaluminum fluoride, methylaluminum dichloride, methylaluminum sesquichloride, diethylaluminum chloride and trimethylaluminum and mixtures thereof. The partial hydrolysis products of aluminum alkyls with alcohols can also be used.

As constituents of hybrid catalysts which can advantageously be used, preference is given to at least one monocyclopentadienyl complex of the formula (I) and a further one of the transition metal coordination compounds mentioned; in particular, all of the transition metal coordination compounds are chemically different. Even though the use of only two transition metal coordination compounds in the hybrid catalyst is particularly preferred, the use of further transition metal coordination compounds is not ruled out.

Preferred combinations of organic transition metal complexes with a monocyclopentadienyl complex of the formula (I) are those in which at least one Cp-free complex, in particular a complex of the formula (X), is used.

The process of the invention is suitable for the polymerization of olefins and especially for the polymerization of 1 -olefins, i.e. hydrocarbons having terminal double bonds, also referred to as α-olefins. Suitable monomers include functionalized olefinically unsaturated compounds such as _es t _{er or} amide derivatives of acrylic or methacrylic acid, for example acrylates, methacrylates, or acrylonitrile. Preference is given to nonpolar olefinic compounds, including aryl-substituted 1-olefins. Particularly preferred α-olefins are linear or branched C ₂ -C ₁₂ -I -alkenes, in particular linear C ₂ -C ₁₀ -I -alkenes such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene or branched C ₂ -C ₁₀ -I -alkenes such as 4-methyl-1-pentene, conjugated and unconjugated dienes such as 1 ,3-butadiene, 1 ,4-hexadiene or 1 ,7-octadiene or vinylaromatic compounds such as styrene or substituted styrene. It is also possible to polymerize mixtures of various 1-olefins. Suitable olefins also include ones in which the double bond is part of a cyclic structure which can have one or more ring systems. Examples are cyclopentene, norbornene, tetracyclododecene and methylnorbornene and dienes such as 5-ethylidene-2-norbornene, norbornadiene and ethylnorbornadiene. It is also possible to polymerize mixtures of two or more olefins.

In particular, the process of the invention can be used for the polymerization or copolymerization of ethylene or propylene. As comonomers in the polymerization of ethylene, preference is given to using C ₃ -C ₈ -I -olefins, in particular 1-butene, 1-pentene, 1-hexene and/or 1-octene. Preferred

comonomers in the polymerization of propylene are ethylene and/or butene. Particular preference is given to a process in which ethylene is copolymerized with 1-hexene or 1 -butene.

The process of the invention for the polymerization of olefins can be carried out using all industrially known polymerization processes at temperatures in the range from 0 to 200 ⁰ C, preferably from 25 to 15O ⁰ C and particularly preferably from 40 to 130°C, under pressures of from 0.05 to 10 MPa and particularly preferably from 0.3 to 4 MPa. The polymerization can be carried out batchwise or preferably continuously in one or more stages. Solution processes, suspension processes, stirred gas-phase processes and gas-phase fluidized-bed processes are all possible. Processes of this type are generally known to those skilled in the art.

The supported or unsupported hybrid catalysts can be subjected to a prepolymerization before use, with prepolymerization of the supported catalyst system being preferred. The prepolymerization can be carried out in the gas phase, in suspension or in the monomer (bulk), with the prepolymerization being able to be carried out continuously in a prepolymerization plant located upstream of the polymerization reactor or in a prepolymerization plant operated batchwise independently of the operation of the reactor.

In the case of suspension polymerizations, the polymerization is usually carried out in a suspension medium, preferably an inert hydrocarbon such as isobutane or a mixture of hydrocarbons or else in the monomers themselves. The suspension polymerization temperatures are usually in the range from -20 to 115 ⁰ C, and the pressure is usually in the range from 0.1 to 10 MPa. The solids content of the suspension is generally in the range from 10 to 80%. The process can be carried out either batchwise, e.g. in stirring autoclaves, or continuously, e.g. in tube reactors, preferably in loop reactors. In particular, it is possible to employ the Phillips PF process as described in US-A 3 242 150 and US-A 3 248 179.

Among the polymerization processes mentioned, preference is given to gas-phase polymerization, in particular in gas-phase fluidized-bed reactors, solution polymerization and suspension polymerization, in particular in loop reactors and stirred tank reactors.

Particular preference is given to gas-phase polymerization in a gas-phase fluidized-bed reactor, in which the circulated reactor gas is fed in at the lower end of a reactor and is taken off again at its upper end. When 1 -olefins are used for the polymerization, the circulated reactor gas is usually a mixture of the 1 -olefin to be polymerized, if desired a molecular weight regulator such as hydrogen and inert gases such as nitrogen and/or lower alkanes such as ethane, propane, butane, pentane or hexane. Preference is given to using propane, if appropriate in combination with further lower alkanes. The velocity of the reactor gas has to be sufficiently high firstly to fluidize the mixed bed of finely divided polymer present in the tube and serving as polymerization zone and secondly to remove the heat of polymerization effectively (noncondensed mode). The

polymerization can also be carried out in the condensed or supercondensed mode in which part of the recycle gas is cooled to below the dew point and is recirculated as a two-phase mixture to the reactor in order to make additional use of the enthalpy of vaporization for cooling the reaction gas.

In gas-phase fluidized-bed reactors, it is advisable to work at pressures from 0.1 to 10 MPa, preferably from 0.5 to 8 MPa and in particular from 1.0 to 3 MPa. In addition, the cooling capacity depends on the temperature at which the (co)polymerization is carried out in the fluidized bed. The process is advantageously carried out at temperatures from 30 to 16O ⁰ C, particularly preferably from 65 to 125°C, with temperatures in the upper part of this range preferably being set for copolymers of relatively high density and temperatures in the lower part of this range preferably being set for copolymers of relatively low density.

It is also possible to use a multizone reactor in which two polymerization zones are linked to one another and the polymer is passed alternately through these two zones a number of times, with the two zones also being able to have different polymerization conditions. Such a reactor is described, for example, in WO 97/04015 and WO 00/02929.

The different or identical polymerization processes can also, if desired, be connected in series so as to form a polymerization cascade. A parallel reactor arrangement using two or more identical or different processes is also possible. However, the polymerization is preferably carried out in only a single reactor.

The process of the invention allows polymer molding compositions having particularly advantageous properties to be prepared. The molding compositions preferably have a polydispersity M _w /M _n of greater than 4, more preferably from 5 to 50, particularly preferably from 7 to 35. The melt mass flow rate measured at 19O ⁰ C under a load of 21.6 kg is preferably from 1 to 300 g/10 min. If catalysts having different comonomer incorporation behaviors are used, the comonomer content of the polymer product and thus in the case of the polymerization of ethylene also the density can also be altered with the proportion of the respective polymer component.

An important application of bimodal or multimodal polyolefins, in particular polyethylenes, is the production of pressure pipes for the transport of gas, drinking water and wastewater, without being restricted thereto. Pressure pipes made of polyethylene are increasingly replacing metal pipes. For such an application, it is important to have a very long useful life of the pipe, without aging and brittle failure having to be feared. Even small flaws or notches on a pressure pipe can grow even at low pressures and lead to brittle failure, and this process can be accelerated by an increasing temperature and/or aggressive chemicals. It is therefore extremely important to reduce the number and size of the flaws of a pipe, e.g. specks or "white spots", as far as at all possible.

Films having a low level of specks and a very high mechanical strength and also excellent

processability can also be obtained. Furthermore, the modifiers used according to the invention do not influence the organoleptic properties of the products and are therefore also particularly suitable for medical and food applications.

The preparation of the products in the reactor reduces the energy consumption, requires no subsequent blending processes and allows simple control of the molecular weight distributions and the polymer components of differing molecular weight. In addition, good mixing of the polymer is achieved.

The parameters used in the present patent application were determined in the following way:

Limiting viscosity [dl/g]

The determination of the limiting viscosity η, which represents the limiting value of the viscosity number on extrapolation of the polymer concentration to zero, was carried out using an automatic Ubbelohde viscometer (Lauda PVS 1) using decalin as solvent at 135°C in accordance with ISO 1628.

Width of the molar mass distribution:

Gel permeation chromatography (GPC) was carried out at 140°C in 1 ,2,4-trichlorobenzene using a Waters 150C GPC apparatus. Evaluation of the data was carried out using the software Win-GPC from HS-Entwicklungsgesellschaft fur wissenschaftliche Hard- und Software mbH, Ober-Hilbersheim. The columns were calibrated by means of polyethylene standards having molar masses of from 100 to 10 ⁷ g/mol. Mass average molar mass (M _w ) and number average molar mass (M _n ) of the polymers and also the ratio of mass average molar mass to number average molar mass (MJM _n ) were determined.

Density and comonomer content:

The density and the comonomer content were determined by means of IR spectroscopy. The IR spectra were measured on films having a thickness of 0.1 mm which had been produced by pressing at 180°C for 15 minutes. The correlation of the IR spectra with the density of the polymer samples was obtained by means of chemical calibration using polymer standards whose density had been determined by measurement of the buoyancy density in accordance with ISO 1183. The correlation of the IR spectra with the comonomer content of the polymer samples was obtained by means of chemical calibration using polymer standards whose hexene content had been determined by evaluation of NMR spectra. To measure the NMR spectra, the polymer standards were introduced into tubes under inert gas and the tubes were flame sealed. In the ¹ H- and ¹³ C-NMR spectra, the

solvent signals, whose chemical shifts were converted into chemical shifts relative to TMS, served as internal standard.

The branches/1000 carbon atoms were determined by means of ¹³ C-NMR ₁ as described by James. C. Randall, JMS-REV. Macromol. Chem. Phys., C29 (2&3), 201-317 (1989), and represent the total CH ₃ group content per 1000 carbon atoms.

Melting point [ ⁰ C]:

The melting point T _m was determined by means of DSC measurement in accordance with

ISO 3146 using a first heating at a heating rate of 2O ⁰ C per minute up to a temperature of 200°C, a dynamic crystallization at a cooling rate of 20°C per minute down to a temperature of 25 ⁰ C and a second heating at a heating rate of 2O ⁰ C per minute back to a temperature of 200 ⁰ C. The melting point is then the temperature at which the curve of enthalpy versus temperature measured in the second heating displays a maximum.

All documents cited are expressly incorporated by reference into this patent application. All amounts and ratios in this patent application are by weight based on the total weight of the mixtures in question, unless indicated otherwise.

The invention is illustrated below with the aid of examples, without being restricted thereto.

Examples

Examples 1-3 and comparative example

3-Methyl-(2-pyridyl-1-methyl)indenylchromium dichloride

was used as transition metal compound. 3-Aminopropyltrimethoxysilane was procured from Aldrich.

Polymerization

Polymerization was carried out at 4O ⁰ C under argon in a 1 I flask provided with stirrer and gas inlet tube. The appropriate amount of MAO (10% strength solution in toluene) was added to a solution of the amount indicated in tables 1 and 2 of the respective complex in 250 ml of toluene and the mixture was heated to 4O ⁰ C. The modifier was then added. 3 ml of hexene were then introduced in each case shortly before the introduction of ethylene. Ethylene was subsequently passed through at a flow rate of from about 20 to 40 l/h at atmospheric pressure. Polymerization was carried out at a constant flow of ethylene and with further addition of hexene for the times indicated in table 1. After the suspension has noticeably acquired a "slurry-like" consistency, the polymerization was stopped by addition of methanolic HCI solution (15 ml of concentrated hydrochloric acid in 50 ml of methanol) in order to rule out diffusion effects. 250 ml of methanol were subsequently added and the white polymer formed was filtered off, washed with methanol and dried at 70°C.

The results of the polymerizations carried out in examples 1 to 3 and comparative example 1 and also the properties of the ethylene copolymers obtained are shown in table 1 below. The reported amount of the C ₆ addition corresponds to the sum of the 3 ml of hexene initially introduced in each case and the hexene added during the polymerization.

Table 1

As comparison of the examples surprisingly shows, choice of the auxiliary makes it possible to influence the comonomer incorporation behavior of the active site of a catalyst or a catalyst component based on a monocyclopentadienyl complex in a targeted way. This provides new degrees of freedom in respect of the targeted control of the product composition or product properties. Extremely different products can thus be obtained using one catalyst system.