MXPA99011332A - Cyclopenta[i]phenanthrene metal complex catalyst systems - Google Patents

Abstract

The invention relates to a method for producing polymers based on monomers with a C=C double bond by homopolymerization or copolymerization of said monomers in the presence of a catalyst system consisting of a metallocene complex A) and a compound forming a metallocenium ions B) and optionally a metal organic compound of the I, II or III main group of the periodic table of elements C). The invention is characterized in that a compound of general formula (I) is used as a metallocene complex A), wherein the substituents and indices have the following meaning:R1 to R11=hydrogen, C1-C10-alkyl, 5 to 7 membered cycloalkyl, which in turn can have C1-C6-alkyl groups as substituents, C6-C15-aryl or arylalkyl and wherein optionally two neighboring radicals R1 to R8 can also stand together for cyclic groups having from 4 to 15 C atoms, or Si(R12)3, R12 standing for C1-C10-alkyl, C6-C15-aryl or C3-C10-cycloalkyl, M=a metal of the III to VI sub-group of the periodic table of elements or a metal of the lanthanide series, X is the same or different and stands for hydrogen, halogen C1-C10-alkyl, C6-C15-aryl, C1-C10-alkoxy or C6-C15-aryloxy, and n=1, 2, 3, 4 or 5, whereby n corresponds to the valence of M minus 1.

Description

The present invention relates to a process for separating polymers based on monomers having a C = C double bond by homopolymerization or copolymerization of these monomers in the presence of a catalyst system comprising a metallocene A complex. ) and a compound B) capable of forming metallocene ions and if desired a metal organ compound of the main group I, or II or III of the Periodic Table of Elements C), catalyst systems which are suitable for polymerizing monomers having a double C = C bond and comprise as active constituents. A) A metallocene complex of the formula (I) wherein the substituents and indices have the following meanings: R1 to R: 11 are hydrogen, alkyl having 1 to 10 carbon atoms, cycloalkyl with 5 to 7 members which in turn can contain alkyl groups with 1 to 6 carbon atoms as substituents, aryl with 6 to 15 carbon atoms or arylalkyl, wherein two adjacent radicals R1 to R8 as a whole can form a cyclic group having from 4 to 15 carbon atoms or Si (R12R Z wherein R12 is alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms or cycloalkyl with 3 to 10 carbon atoms, M is a metal of transition groups III to VI of the Periodic Table of the Elements or a metal of the lanthanide series, X are identical or different and are hydrogen, halogen, alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkoxy with 1 to 10 carbon atoms or aryloxy with 6 to 15 carbon atoms n is 1, 2, 3, 4 or 5, where n corresponds to the valence of M minus 1, a compound capable of forming metallocene ions and, if desired, C) a metal organ compound of the main group I, II or III of the Periodic Table of the Elements, metallocene complexes of the formula (I) wherein the substituents and indices have the following meanings: R1 to R11 are hydrogen, alkyl having 1 to 10 carbon atoms, cycloalkyl with 5 to 7 members which may in turn contain alkyl groups with 1 to 6 carbon atoms as substituents , aryl with 6 to 15 atoms carbon or arylalkyl, wherein two adjacent radicals R1 to R8 together can form a cyclic group having from 4 to 15 carbon atoms or Si (R12) 3, wherein R12 is alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms or cycloalkyl with 3 to 10 carbon atoms, M is a metal of transition groups III to VI of the Periodic Table of the Elements or a metal of the lanthanide series, X are identical or different and are hydrogen, halogen, alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkoxy with 1 to 10 carbon atoms or aryloxy with 6 to 15 carbon atoms Y n is 1, 2, 3, 4 or 5, where n corresponds to the valence of M minus 1. The present invention is further related to polymers which are based on monomers having a C = C double bond and are held by homopolymerization or copolymerization of these monomers in the presence of a catalyst system comprising a metallocene complex A) and a compound B) capable of forming metallocene ions and, if desired, an organometallic compound of the main group I, II or III of the Periodic Table of the Elements and C) also fibers, films, or molded parts comprising these polymers and the use of metallocene complexes (I) as components in catalyst systems or as catalysts. Syndiotactic styrene polymers are known. Due to their properties profile, for example high hardness, high rigidity, dimensional stability and low dielectric constants, they can be used, for example, as electrical or mechanical components. One object of the present invention is to find novel catalyst systems which can be employed at relatively high polymerization temperatures, preferably above 60 ° C, have a high polymerization activity and give a polymer having a high proportion, preferably over 80% determined by extraction of the crude polymer with n-butanone (from syndiotactic structural units and high molecular weight) M ". We have found that this goal is achieved by a process to prepare monomer-based polymers having a C = C double bond by homopolymerization or copolymerization of these monomers, in the presence of a catalyst system comprising a metallocene complex A) and a compound B) capable of forming metallocene ions and an organometallic compound of the main body is desired. , II or III of the Periodic Table of Elements C), wherein the metallocene complex A) used is a compound of the formula (I) wherein the substituents and indices have the following meanings: R1 to R11 are hydrogen, alkyl having 1 to 10 carbon atoms, cycloalkyl with 5 to 7 members which may in turn contain alkyl groups with 1 to 6 carbon atoms as substituents, aryl with 6 to 15 carbon atoms or arylalkyl wherein two adjacent radicals R1 to R8 can together form a cyclic group having from 4 to 15 carbon atoms or Si (R12) 3, wherein R12 is alkyl with 1 at 10 carbon atoms, aryl with 6 to 15 carbon atoms or cycloalkyl with 3 to 10 carbon atoms, M is a metal of transition groups III to VI of the Periodic Table of the Elements or a metal of the lanthanide series, X are identical or different and are hydrogen, halogen, alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkoxy with 1 to 10 carbon atoms or aryloxy with 6 to 15 carbon atoms and n is l, 2, 3, 4 or 5 where n corresponds to the valence of M minus 1. By catalyst systems that are suitable for polymerizing monomers that have a C = C double bond and comprise as active constituents: A) A metallocene complex of the formula 'I B) a compound capable of forming metallocene ions and, if desired, C) an organometallic compound of the main groups I, II, or III of the Periodic Table of the Elements, by metallocene complexes of the formula (I) wherein the substituents and indices have the following meanings: R1 to R11 are hydrogen, alkyl with 1 to 10 carbon atoms, cycloalkyl with 5 to 7 members, which in turn can contain alkyl groups with 1 to 6 carbon atoms as substituents, aryl with 6 to 15 carbon atoms or arylalkyl , wherein two adjacent radicals R1 to R8 together can form a cyclic group having from 4 to 15 carbon atoms or Si (R12) 3, wherein R12 is alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon or cycloalkyl atoms with 3 to 10 carbon atoms, M is a metal of transition groups III to VI of the Periodic Table of the Elements or a metal of the lanthanide series, X are identical or different and are hydrogen, halogen, alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkoxy with 1 to 10 carbon atoms or aryloxy with 6 to 15 carbon atoms AND n is 1, 2, 3, 4 or 5 where n corresponds to the valence of M minus 1, by polymers based on monomers having a C = C double bond if they are obtained by homopolymerization or copolymerization of these monomers in the presence of a catalyst system comprising a metallocene complex A), a compound B) capable of forming metallocene ions and if you want an organometallic compound of the main groups I, II or III of the Periodic Table of Elements C), wherein the metallocene complex A) used is a compound of the formula I: wherein the substituents and indices have the following meanings: R1 to R11 are hydrogen, alkyl with 1 to 10 carbon atoms, cycloalkyl with 5 to 7 members, which in turn can contain alkyl groups with 1 to 6 carbon atoms as substituents, aryl with 6 to 15 carbon atoms or arylalkyl wherein the two adjacent radicals R1 to R8 together can form a cyclic group having from 4 to 15 carbon atoms or Si (R12) 3, wherein R 1-2 is alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms or cycloalkyl with 3 to 10 carbon atoms, M is a metal of transition groups III to VI of the Periodic Table of the Elements or a metal of the lanthanide seriesX are identical or different and represent hydrogen, halogen, alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkoxy with 1 to 10 carbon atoms or aryloxy with 6 to 15 carbon atoms and n is , 2, 3, 4 or 5 where n corresponds to the valence of M minus 1, by fibers, films and molded parts comprising the polymers of the present invention and also by the use of metallocene complexes (I) of the present invention, as components in catalyst systems or as catalysts. Convenient monomers are generally those that have a polymerizable carbon-carbon (C = C) double bond. Examples are linear alkenes having from 2 to 20 carbon atoms, wherein the double bond can be in an internal or terminal position, and cyclic or bi-cyclic alkenes having 3 to 20 carbon atoms, wherein the double bond C = C can be in an endo or exo position. The linear or cyclic alkenes can be replaced by functional groups such as halogen, an ester group, a -COOH group or a nitrile group. Examples of these monomers are vinyl chloride, ethylacrylate, methyl acrylate, methyl methacrylate and acrylonitrile. The linear and cyclic alkenes are preferably hydrocarbons without heteroatoms. Examples of these monomers are alk-1-ene with 12 to 20 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, cycloalkyls such as cyclopentene, cyclohexene, bicycloalkenes, such as norbonene and also dienes such as 1,3-butadiene, cyclopentadiene, norbornadiene. Preferred non-aromatic monomers are ethylene, propylene and 1,3-butadiene.

For the purposes of the present invention, preferred aromatic monomers are vinyl aromatic compounds of the formula (II) wherein the substituents and indices have the following meanings: R13 is hydrogen or alkyl having 1 to 4 carbon atoms, R14 to R18 independently of one another are hydrogen, alkyl having 1 to 2 carbon atoms, aryl having 6 to 18 carbon atoms , halogen or 2 adjacent radicals together form a cyclic group having from 4 to 15 carbon atoms. Preference is given to using vinyl aromatic compounds of the formula II wherein R 13 is hydrogen and R14 and R18 are hydrogen, alkyl having 1 to 4 carbon atoms, chlorine or phenyl or two adjacent radicals together form a cyclic group having from 4 to 12 carbon atoms, resulting in compounds of the formula (II) which for example they are naphthalene derivatives or anthracene derivatives. Examples of these preferred compounds II are: styrene, p-methylstyrene, p-chlorostyrene, 2,4-di-ethylstyrene, 1, -divinylbenzene, 4-vinylstyrene, 2-vinylnaphthalene and 9-vinylanthracene. It is also possible to use mixtures of various vinyl aromatic compounds (II), it is preferred to use only one vinyl aromatic compound. Particularly preferred vinyl aromatic compounds are styrene and p-methylstyrene. The preparation of vinyl aromatic compounds of the formula (II) is known per se and is described, for example, in Bellstein 5, 367, 474, 485. Other monomers which can be used are branched monomers having at least two vinyl aromatic functional radicals, example tetrakis (4-vinylbenzyl) and titanium or tetrakis (4-vinylbenzyl) silane.

Additional monomers of this type are described in the prior German patent application No. 196 34 375.5-44. In general, the monomers can also be used as a mixture. In this case, the mixing ratio is not generally critical. Component A) of the catalyst system of the present invention is a metallocene complex of the formula (I) wherein the substituents and indices have the following meanings: R1 to R11 are hydrogen, alkyl having 1 to 10 carbon atoms, cycloalkyl with 5 to 7 members which in turn can contain alkyl groups with 1 to 6 carbon atoms or as substituents , aryl with 6 to 15 atoms carbon or arylalkyl wherein two adjacent radicals R1 to R8 together can form a cyclic group having from 4 to 15 carbon atoms or Si (R12) 3, wherein R12 is alkyl with 1 to 10 carbon atoms, aryl with 6 at 15 carbon atoms or cycloalkyl with 3 to 10 carbon atoms, M is a metal of transition groups III to VI of the Periodic Table of the Elements or a metal of the lanthanide series, X are identical or different and represent hydrogen, halogen, alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkoxy with 1 to 10 carbon atoms or aryloxy with 6 to 15 carbon atoms and n is 1, 2, 3, 4 or 5 , where n corresponds to the valence of M minus 1. Particularly preferred metallocene complexes of the formula (I) are those in which: M is a metal of transition groups III to VI of the Periodic Table of the Elements in particular titanium, . X is alkyl having 1 to 10 carbon atoms, alkoxy with 1 to 10 carbon atoms or halogen and n is 3. Mixtures of various metallocene complexes can also be used. Examples of metallocene compounds (I) can also be used. Examples of metallocene compounds (I) according to the present invention are cyclopenta (I) trivantitanium trichloride, 2-methyl cyclopenta (I) trivantitanium trichloride and 2-phenyl cyclopenta (I) trivantitanium trichloride. The synthesis of the metallocene complexes (I) of the present invention generally starts from 9,10-phenanthrenquinone or ring-substituted derivatives of this basic molecule. The 9, 10-phenanthrenquinone or its derivative, then becomes general as described by B Elliasson, J. Org. Chem. (1989), pages 171 to 175 and AC Cope, J. Am. Chem. Soc. (1956), pages 2547 to 2551, in the ketone precursor, 2,3-dihydro-2-oxo-lH-cyclopenta [ 1] phenanthrene or its derivative, and finally by reducing the keto group organometallic compounds or hydrogen reducers in hydrocarbon III or its tautomers.

The metallocene complexes (I) of the present invention in. are obtained by deprotonation of the hydrocarbon (III) using a strong base, preferably organometallic, for example n-butyllithium, subsequently reacting it with a silylating reagent, preferably trimethylfluorosilane and finally reacting the product with the transition metal halide, preferably a halide of the transition group IV of the Periodic Table of the Elements, for example titanium tetrachloride, zirconium tetrachloride or hafnium tetrachloride. The additional conditions for this reaction are known to those skilled in the art and are describe for example in J. Organomet. Chem. (1989), pages 359 to 370. Preference is given to carry out the reactions in organic solvents such as diethyl ether, tetrahydrofuran, toluene or methylene chloride at a reaction temperature in the range of -78 ° C to 150 ° C. ° C. All the aforementioned reaction steps can be carried out without isolation and purification of the intermediates, but the intermediates are preferably isolated and purified. As compounds B) capable of forming metallocene ions, the catalyst systems may comprise open-chain or cyclic aluminoxane compounds. or R19 wherein R19 is an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or ethyl and k is an integer from 5 to 30, preferably from 10 to 25. The preparation of these oligomeric aluminoxane compounds is usually carried out upon reaction of a trialkylaluminum solution with water and is described inter alia in EP-A 284 708 and the US patent No. 4,794,096. The oligomeric aluminoxane compounds obtained in this manner are generally in the form of mixtures of both linear and cyclic chain molecules of various lengths, such that k should be considered as an average value. The alu-oxane compounds may also be present in admixture with other metal alkyls, preferably with aluminum alkyls. It has been found to be advantageous to use the metallocene complexes and the oligomeric aluminoxane compound in amounts such that the atomic ratio of aluminum of the oligomeric aluminoxane compound to the transition metal of the metallocene complexes is in the range of 10: 1 to 106: 1, preferably in the range of 10: 1 to 104: 1 and in particular of 20: 1 to 9000: 1. Other compounds B) capable of forming metallocene ions that can be used, are coordination complexes selected from the group consisting of acids of uncharged, strong Lewis, ionic compounds having Lewis acid cations and ionic compounds having Brdnsted acids as cations. As strong uncharged Lewis acids, preference is given to compounds of the formula (VI) M ^^ X3 (VI) wherein M1 is an element of the main group III of the Periodic Table, in particular B, Al or Ga preferably B, X1, X2 and X3 are hydrogen, alkyl having 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkylaryl, arylalkyl, haloalkyl or haloaryl, each having 1 to 10 carbon atoms in the radical alkyl and from 6 to 20 carbon atoms in the aryl radical or fluorine, chlorine, bromine or iodine, in particular haloaryls, preferably pentafluorophenyl. Particular preference is given to compounds of the formula VI wherein XL, X2 and X3 are identical, preferably tris (pentafluorophenyl) borane. These rosy compounds for their preparation are known per se and are described, for example, in WO 93/3067.

Suitable ionic compounds having Lewis acid cations are compounds of formula VII d + [(Ya +) Q? Q2 ... Qz] (vii; where it is an element of major groups I to VI or of transition groups I to VIII of the Periodic Table. Qi to Qz are negatively charged radicals such as alkyl with 1 to 28 carbon atoms, aryl with 6 to 15 carbon atoms, 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, and from 1 to 28 carbon atoms in the alkyl radical, cycloalkyl with 1 to 10 carbon atoms which may contain alkyl groups with 1 to 10 carbon atoms as substituents, halogen, alkoxy with 1 to 28 carbon atoms, aryloxy with 6 to 15 carbon atoms carbon, silyl or mercaptyl groups, is an integer from 1 to 6, z is an integer from 0 to 5, and d corresponds to the difference a - z, but d is greater than or equal to 1. Particularly convenient cations are carbonium cations, oxonium cations and sulfonium cations and also cationic transition metal complexes. Special mention may be made of the triphenylmethyl cation, the silver cation and the 1,1'-dimethyl ferrocenyl cation. Preferably they have non-coordinating counterions, in particular boron compounds as also mentioned in WO 91/09882, preferably tetrakis (pentafluorophenyl) borate. Ionic compounds having Brdnsted acids as cations and preferably similar non-coordination counterions are mentioned in WO 93/3067, the preferred cation being N, N-dimethylanilinium. It has been found to be particularly useful that the boron molar ratio of the compound capable of forming metallocene to transition metal ions from the metallocene complex, is in the range from .1: 1 to 10: 1, particularly in the range of 1: 1 to 5: 1. The catalyst systems of the present invention may further comprise a compound organometallic of the main groups I, II or III of the periodic table as component C). Examples which may be mentioned are n-butylthio, butyloctylmagnesium, triethyl boron and preferably aluminum compounds. The aluminum compounds can have, for example, the formula VIII A1R20R21R22 (VIII) wherein R20 to R22 are hydrogen fluorine, chlorine, bromine, iodine or alkyl having 1 to 12 carbon atoms, preferably alkyl having 1 to 8 carbon atoms. carbon The radicals R20 and R21 are preferably identical and are alkyl having 1 to 6 carbon atoms such as methyl, ethyl, isobutyl or n-hexyl; R22 is preferably hydrogen. An example that may be mentioned is diisobutyl aluminum hydride. In general, the molar ratio C): I) is in the range of 1: 1 to 2000: 1, preferably 10: 1 to 800: 1. In general, the molar ratio C): B) and here particularly C): aluminum IV, V is in the range of .001: 1 to 10,000: 1, preferably .01: 1 to 5000: 1. The catalyst systems of the present invention, or at least one of its components A) to C), by For example, the metallocene complexes (I) can be used in supported or unsupported form. Suitable support materials for example are silica gels, preferably those of the formula Si02.bAl203, wherein b is from 0 to 2, preferably from 0 to 0.5; that is, essentially aluminosilicates or silicon dioxide. The supports preferably have a particle diameter in the range from 1 to 200 μm, in particular from 30 to 80 μm. These products are commercially available, for example as Silica Gel 332 from Grace. Additional supports, among others, are finely divided polyolefins, for example polypropylene or finely divided polyethylene, but also polyethylene glycol, polybutylene terephthalate, polyethylene terephthalate, polyvinyl alcohol, polyethylene, syndiotactic polystyrene, polybutadiene, polycarbonates or their copolymers. The polymerization process of the present invention can be carried out essentially from -78 ° C to 150 ° C, preferably from 0 to 120 ° C; The polymerization temperature can also change over time and / or in space. It has been found advantageous to carry out the polymerization from 60 ° C to 150 ° C, preferably from 70 ° C to 150 ° C. It was unexpected that at these high temperatures polymerization, the activity of the catalyst system of the present invention, calculated as g of polymer / mol of the transition metal x mol of monomer xh, and the molecular weight M "of the polymer determined by GPC as defined below, remains at a high level and that in addition, the syndiotacticity of the polymer, measured by extraction with n-butanone as already described, is still more than 40%, preferably more than 80% In general, the process of the present invention is carried out at a pressure from .5 to 300 bar, preferably from 1 to 200 bar, in particular from 1 to 20 bar.The process of the present invention can be carried out continuously or in batches.Different process variants have been found useful In bulk solution or bulk monomer polymerization, the process of preference comprises initially charging the monomer, preferably the vinyl aromatic compound (II) defined above, in particular styrene, preferably heating it from 60 ° C to 100 ° C and then adding to compound B) capable of forming metallocene ions , preferably methylaluminoxane or tris (pentafluorophenyl) borane or N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate or a mixture of these components A) and if desired also component C). Component A), if desired in a solvent, is then added. However, also it is possible to mix the metallocene complex A) in advance with the compound B) capable of forming metallocene ions and introducing this mixture into the reactor. In general, polymerization is then carried out for a period of 10 to 90 minutes and the polymerization is stopped by the addition of methanol, the polymer is washed with methanol and dried at 40 ° C to 100 ° C. The process of the present invention can also be carried out as a dispersion polymerization as described in DE-A 195 42 356. Examples of suitable dispersants are styrene-diene two-block copolymers or styrene-diene-styrene three-block copolymers , preferred expression means are aliphatic hydrocarbons. The dispersant is preferably used in an amount of 1 to 10% by weight based on the amount of vinyl aromatic compounds used. The dispersion is advantageously added to be polymerized as a solution in the vinyl aromatic monomer. Suitable two-block copolymers can consist of a polymer block constituted by ethylene and a polymer block constituted by butadiene, preferably 1,4-polybutadiene. The sum of weight percent of blocks constituted by styrene and butadiene is 100%, with the composition being able to vary. He The styrene block can consist of 10 to 90% by weight, preferably 20 to 80% by weight, the butadiene block can correspondingly be 90 to 10% by weight, preferably 80 to 20% by weight. Copolymers of two styrene-butadiene blocks that can be hydrogenated are also convenient. Examples of suitable three styrene-diene-styrene block copolymers are those in which the diene block comprises polybutadiene or polyisoprene and wherein the diene block can be hydrogenated or non-hydrogenated. Two-block and three-block copolymers and processes for their preparation are known per se and are described for example in Thermoplastic elastomers (Thermoplastic Elastomers) (1987), N.R. Liege et al. (Ed.). Convenient copolymers are also commercially available for example Kraton ™ grades (Shell). Aliphatic hydrocarbons which are particularly suitable as a dispersion medium are those having from 4 to 10 carbon atoms, for example butane, isobutane, pentane, hexane and heptane or mixtures of hydrocarbons. The preferred method in the process of the present invention is to dissolve the dispersant in the vinyl aromatic compound, add the dispersion medium, preferably in an amount of 1 to 10% by weight based on the vinyl aromatic compound, then pass the olefinic compound and add the metallocene catalyst system. The polymerization can be stopped by the addition of protic compounds such as methanol and the dispersion medium can be removed by increasing the temperature or if desired it can be circulated. In addition, the process of the present invention can be carried out as a suspension polymerization as described in DE-A 195 09 785. In this method, the monomer or mixture of monomers, preferably the vinyl aromatic compound (II) in general it is polymerized at a pressure of 5 to 300 bar, preferably of 6 to 100 bar, in particular of 7 to 50 bar, in the presence of hydrocarbons with 1 to 4 aliphatic carbon atoms. Preference is given to hydrocarbons with 3 to 4 linear or branched aliphatic carbon atoms, such as propane or isobutane, and the catalyst system of the present invention or at least one of its components A), B) or C) is generally present in supported form, preferably in porous silica gel. The process of the present invention can be carried out in various reactors. Suitable reactors are stirred reactors, kneaders and preferably extruders.

A particular mode of the process comprises carrying out this process using a co-rotating extruder, hermetic coupling and thus self-cleaning, with twin spindles, preferably in one stage. The reaction temperature in general is from -78 ° C to 150 ° C, preferably from 0 ° C to 150 ° C, in particular from 60 ° to 150 ° C. However, it is also possible for a temperature gradient to be applied from 0 ° C to 150 ° C by heatable jackets around the reaction tube. The extruder can have a plurality of individual zones that can be heated at different temperatures. The external diameter of the conveying and kneading elements with double, co-rotating blades, preferably double blades of the twin-screw extruder is preferably in the range of 25 to 70 mm, in particular 30 to 58 mm. The clearances between the extruder barrel and the spindle element are in the range of .2 to .8 mm, in particular of .3 to .5 mm. The rotational speed of the spindles can be in the range of 2 to 500 revolutions per minute, preferably 5 to 30 revolutions per minute.

The average residence time in the extruder can be from .1 to 240 minutes, preferably from 2 to 20 minutes. The average residence time of the extruder can be regulated by the number of barrel sections. The number of barrel sections preferably is in the range of 6 to 20, in particular from 8 to 12. Particular preference is given to using 10 barrel sections, where it is carried out against degassed in the first barrel section, the starting materials are dosed to the second barrel section, the barrel sections 3 to 8 are reaction sections, the barrel sections 9 and 10 can be heated to different temperature and the barrel section 10 serves as a discharge barrel. The preference process is carried out by mixing the vinyl aromatic compound and if desired additional monomers defined above, the compound B) capable of forming metallocene ions and if desired the compound C) under an atmosphere of the cabinet and feeding them to the first barrel section of the extruder. Parallel to this, a solution or suspension of the transition metal complex A) (to the first barrel section) can also be fed. As solvents or suspending media, mention may be made of cyclic hydrocarbons and acyclics such such as butanes, pentanes, hexanes or heptanes, also aromatic hydrocarbons such as benzene, toluene or ethylenethylene and oxygen-containing hydrocarbons such as tetrahydrofuran, halogen-containing hydrocarbons such as dichloromethane or nitrogen-containing hydrocarbons such as n-methyl piperidine and also their mixtures . The metered amount preferably is chosen from 500 to 2000 g / h of the vinyl aromatic compound mixture, if desired additional monomers defined above are supplied, components B) and if employed, C) are fed from 100 to 200 cm3 / h of the solution or suspension of the metal complex. The polymerization is preferably carried out in an aromatic vinyl compound and, if desired, additional monomers previously defined as a reaction medium, is decix in bulk. The process is technically simple to carry out, high conversions are achieved and the risk of extruder exit holes blocked by polymer is low. A further preferred embodiment comprises activating the reaction mixture comprising vinyl aromatic monomers (II), if desired additional monomers defined above and the catalyst system which comprises A), B), and if desired C), by pre-mixing and subsequently polymerizing in a mixing kneader. Pre-mixing is preferably carried out at a temperature at which the reaction mixture is still liquid and the polymerization is not initiated. Depending on the components used for the reaction mixture, this temperature is in the range from -30 to + 140 ° C, preferably from 0 ° C to 70 ° C and in particular from 15 to 30 ° C is preferred. Furthermore, in the activation according to the present invention, pre-mixing is preferably carried out with the residence time and the temperature selected such that not only the start of the polymerization reaction but also damage to the catalyst system are avoided. despite sufficient mixing for activation. The activation by pre-mixing of the reaction mixture is advantageously carried out in a short time or immediately before the polymerization reaction. The time between activation by pre-mixing and polymerization is from 0 to 60 minutes, preferably from .01 to 45 minutes and particularly preferably from .1 to 30 minutes. Pre-mixing is preferably carried out essentially without the initiation of a reaction. The process is advantageously carried out without solvent. In a particularly preferred embodiment of process, the monomers used initially act as solvents. In addition, it is advantageous to carry out the process in an inert gas atmosphere, for example nitrogen or argon, if possible with the exclusion of moisture. Hydrogen may also be metered into the inert gas stream. Pre-mixing is preferably carried out in such a way that no reaction occurs. further, it is advantageous that the polymers are obtained in a form that can be further processed, for example extruded, essentially immediately after polymerization. This is preferably the case when the polymerization in the process is directed to high yields and the compliance polymer has a low residual monomer content. This residual monomer content is less than 10% by weight, preferably less than 5% by weight and particularly preferably less than 3% by weight, based on the weight of the polymer. The remaining monomers in the polymer can be removed, for example by distillation or vacuum application. The process of the present invention is preferably carried out in a roasting-mixing reactor with an extruder connected downstream, without further processing steps, for example distillative separation of relatively large quantities of residual monomer which are obtained, Particularly in the case of low conversions, they have to be carried out. The process by therefore, it allows greater processing of the polymer essentially immediately after its preparation. If the polymerization of the present invention is carried out in the presence of branched monomers having at least two vinyl aromatic functional radicals, for example tetrakis (4-vinylbenzene) titanium or tetrakis (4-vinylbenzyl) silane, polymers are generally obtained star as described in the prior German patent application 196 34 375.5-44. The linear polymers obtained using the process of the present invention, usually have a molecular weight IX, determined by gel permeation chromatography at 135 ° C in 1,2,4-trichlorobenzene as a solvent against a polystyrene standard, in the range of ,000 to 2 x 106 preferably in the range of 50,000 to 106. The syndiotacticity of the polymers obtained using the process of the present invention is generally in the range of 30 to 100%, preferably in the range of 60. to 100%, in particular from 80 to 100% and very particularly preferably in the range from 90 to 100%. The syndiotacticity is determined by extracting a baked and weighed amount of polymer with 2-butanone for 24 hours, and drying and weighing the insoluble part of the polymer.

Preparation of 3-hydro-2-hydroxy-2-methyl-methyl-1H-cyclopenta [I] phenanthrene 8.83 ml of a 3M solution of methyl magnesium bromide in diethyl ether (26.49 mmol) was added dropwise under protective gas to a suspension of 5.00 g of 2,3-dihydro-2-oxo-lH-cyclopenta [I] phenanthrene (21.19 mmoles) in 20 ml of diethyl ether. After refluxing for 3 hours, the product is hydrolyzed by careful addition of 10 ml of 2N hydrochloric acid. Extract the mixture three times with diethyl ether, stir the organic phase with saturated NaHS03 solution, saturated NaHCO3 solution and a little of water, dry over Na2SO and evaporate the solution of a colorless solid. Yield: 4.48 g (89%) MS: M +: 248 m / e (33%) M + -CH3CO: 205 m / e (100%) NMR (CDC13, 600 MHz) Position displacedMulti Intendesplazamiento plicity chemical chemical aH 13C 4.5 8.68-8.70 m 2 126.71 125.83 1-3, 6-8 7.77-7.79 m 2 124.76 123.22 7.59-7.63 m 4 cuat.C: 129.83 130.27 123.09 135.02 OH (C-OH) 1.98 bs 1 79.49 CH2 3.44 2d (J = 15. 4 48.06 8Hz Me 1.98 -1.66 s 3 28.46 Preparation of lH-2-methylcyclopenta [I] phenanthrene 4.56 g of 3-hydro-2-hydroxy-2-methyl-lH-cyclopenta [I] phenanthrene (18.39 mmol) were dehydrated on heating for one hour with 0.25 g of p-acid. -Toluenesulfonic monohydrate in 300 ml of toluene in a water separator.

The blue-green solution changed to a reddish color after dilution with diethyl ether. The resulting solution is stirred with saturated sodium bicarbonate solution, dried over magnesium sulfate and evaporated. This gave a beige substance that by being purified by rapid filtration of a glass frit filled with flash silica gel (petroleum ether: ethyl acetate). Yield: 4.02 g (95%) MS: M +: 230 m / e (33%) M + -Me: 215 m / e (38%) Elemental analysis: C18H14 C: (cale.) 93.87 (found) 93.63 C: ( cale.) 6.13 (found) 6.17 NMR (250 MHz): PossessionMultiIntendesplazation of chemical chemical effects 1H 13C 4.5 8.68-8.70 m 2 126.65 126.27 (8.56-8.62) PossessionMultipleInstruction of Chemical Chemical Complaint 1H 13C 1-3, 6-8 8.10-8.13 m 1 125.51 125.14 (8.04-8.07) 7.93-7.95 m 1 124.60 124.39 (7.74-7.77) 7.53-7.65 m 4 123.61 123.63 7.40-7.50 ) 9 7.07 (6.90) bs 1 123.25 cuat .C: 127.50 128.30 129.64 130.19 137.05 140.22 11 3.74 (3.20) s 2 42.95 Me 2.33 (1.99) bs 3 16.94 Preparation of lH-2-phenylcyclopenta [I] phenanthrene 1 g of 2,3-dihydro-2-oxo-lH-cyclopenta [I] phenanthrene (4.31 mmol) in 100 ml of toluene are added dropwise at 0 ° C to 2 ° C. ml of a 3M solution of phenyl magnesium bromide in diethyl ether (6 mmol). The mixture is allowed to come to room temperature and is stirred for two hours. After hydrolysis with saturated ammonium chloride solution, the mixture is extracted with diethyl ether, the The organic phase is washed with saturated sodium chloride solution, dried over magnesium sulfate and evaporated to dryness. The residue is taken up in 100 ml of toluene and refluxed for two hours with 100 mg of toluene sulphonic acid.

After addition of saturated sodium hydrogen carbonate solution, the mixture is extracted with diethyl ether, the organic phase is dried over magnesium sulfate and evaporated.

After flash chromatography (petroleum ether: ethyl acetate = 50: 1). lH-2-phenylcyclopenta [I] phenanthrene is obtained as colorless needles. Yield: 4.50 g (36%) MS: M +: 292 m / e (100%) M + -Ph: 215 m / e (6%) Elemental analysis: C23Hi6 C: (cale.) 94.48 (found) 94.66 C: ( cale.) 5.52 (found) 5.63 NMR (CDC13, 600 MHz): Position displacement Multi-plicity Chemical distention Chemical activity 13C 1 8.02 d (J = 7.7Hz) 1 123.84 2 + 3 7.62-7.56 m 2 124.85 125.25 4 8.68 d (J = 8.2Hz) 1 123.51 5 8.72 d (J = 7.1Hz) 1 123.34 Displacement Position Multi-plicity Chemical Displacement! Chemical Sity 13C 6 + 7 7.66-7.64 2 125.87, 126.50 8 8.20 d (J = 7.0Hz) 1 124.29 9 7.79 s 1 124.43 11 4.20 s 2 39.22 o-Ph 7.75 d (J = 7.3Hz) 2 125.50 ra-Ph 7.42 d (J = 7.3Hz) 2 128.79 p-Ph 7.29 d (J = 7.3Hz) 1 127.39 cuat C 146.43, 139.97 137.74, 136.03 130.33, 136.03 128.93, 127.56 General method for preparing 1-trimethyl-silyl-cyclopenta [I] -phenanthrenes. The respective cyclopenta [I] phenanthrene (10 mmoles) was initially charged in 20 ml of THF and mixed while cooling on ice with 10 mmoles of n-BuLi as a 1.6 M solution in hexane. The mixture was allowed to come to room temperature and stirred overnight. The dark green solution evaporates to dryness. 1-trimethylsilylcyclopenta [I] phenanthrene Yield: 2.05 g (90%) yellow oil MS: M +: 288 m / e (30%) M + -TMS: 215 m / e (10%) TMS: 73 m / e (100%) ) Elemental analysis: XH NMR (CDCI3, 250 MHz) Position displacement Multiplicity Chemical intensity 'H Skeleton 8.75-8.70 m 2 phenanthrene 8.26-8.22 m 1 8.02-7.97 m 1 + Cp-H 7.65-7.53 m 5 Cp-H 6.89-6.86 m 1 Cp-H 4.35 bs 1 TMS -0.05 s 9 l-trimethylsilyl-2-methylcyclopenta [I] phenanthrene Yield: 2.60 g (86%) yellow oil MS: M +: 302 m / e (40%) M + -TMS: 228 m / e (10%) TMS: 73 m / e (100%)? NMR (CDCl 3, 250 MHz) Position displacement Multiplicity Chemical intensity XH Skeleton 8-71-8. 64 m 2 phenanthrene Position displacement Multiplication Chemical intensity 2H 8.15-8.12 m 1 7.88-7.85 m 1 7.63-7.48 m 4 Cp-H 7.13 s 1 Cp-H 4.15 s 1 Me 2.35 s 3 TMS -0.08 s 9 l-Trimethylsilyl-2-phenylcyclopenta [I] phenanthrene Yield: 2.76 g (76%) beige oil MS: M +: 364 m / e (20%) M + -TMS: 291 m / e (7%) TMS: 73 m / e (65%) XH NMR (CDC13, 250 MHz) Position displacement Multiplicity Chemical intensity XH Skeleton 8.73-8.68 m 2 phenanthrene 8.27-8.24 m 1 8.04-8.00 m 1 + Ph-H 7.68-7.53 m 6 Cp-H 7.70 s 1 Ph-H 7.45-7.39 m 1 Position displacement Multiplicity Chemical intensity H Ph-H 7.32-7.25 m 1 Cp-H 4.91 s 1 TMS -0.05 s 9 General method for preparing cyclopenta trichloride [I] phenanthrene titanium and derivatives. 1-trimethylsilylcyclopenta [I] phenanthrene or its 2-methyl or 2-phenyl derivatives (batch size corresponds to the amounts obtained above) is dissolved in 30 mL of chloromethylene and mixed at 0 ° C with an equimolar amount of titanium tetrachloride. The orange solution immediately turned reddish brown. After stirring for 4 hours at room temperature, the mixture was cooled to -30 ° C overnight. After decanting the solution, the product could be obtained as a dark red solid. The yield could be improved considerably by concentrating the mother liquor and cooling again. The numbering of the following cyclopenta [I] fenantrenss in the NMR tables is in accordance with the general scheme: Cyclopenta [1] phenanthrene titanium trichloride Yield: 1.76 g (53%) red solid MS: M +: 370 m / e (7%) M + -TMS: 333 m / e (1%) TMS: 215 m / e (100 %) Elemental analysis: C ^ Hu iCla C: (cale.) 55.26 (found) 54.77 C: (cale.) 3.00 (found) 3.22 NMR (CDC13, 600 MHz): aH 13C Position displazami MultiIntendisplacement to chemical plicidad sidad chemical 13C XH 4.5 8.56 d (J = 8.0H 2 124.07 z) 2,3,6,7 7.73-7.67 m 4 128.32, 130.07 1.8 8.23 d (J = 7.4H 2 125.47 z) Position displazami MultiIntendisplacement in chemical plicidad sidad chemical 13C aH 9,11 7.62 d (J = 3.3H 2 115.42 z) 10 7.25 t (J = 3.3H 1 123.09 z) C cuat 131.17, 131.10, 127.57, -126 2-methylcyclopenta [I] phenanthrene titanium trichloride Yield: 1.75 g (53%) red solid MS: M +: 384 m / e (8%) M + -C1: 347 m / e (2%) M + -2C1: 311 m / e (2%) MeLig-H: 229 m / e (100%) Elemental Analysis: C: (cale.) 56.37 (found) 55.98 C: (cale.) 3.42 (found) 3.54 NMR (CDC13, 600 MHz): XH 13C Position displacement Multi- Inten- chemical shift * H chemical plicity 13C 4.5 8.54 d (J = 7.9Hz) 2 124.02 Position displacement MultiIntendesplazamiento chemist * Hplicidad sidad chemist 13C 2,3,6,7 7.71-7.65 m 4 128.25, 129.80 1.8 8.18 d (J = 7.6Hz) 2 125.13 9.11 7.47 s 2 115.85 Me 2.73 s 3 18.87 C cuat 131.64, 130.89, 128.07, 125.19 2-Phenylcyclopenta [I] fenantren titanium chloride Yield: 2.23 g (66%) red solid MS: M +: 446 m / e (6%) PhLig-H: 291 m / e (100%) Elemental analysis: C: (cale.) 61.99 (found) 61.67 C: (cale.) 3.39 (found) 3.80 NMR (CDC13, 600 MHz): XH 13C Position displacement MultiIntendesplazamiento chemist * Hplicidad sidad chemist 13C 4.5 8.57 d (J = 7.7Hz) 2 124.46 2.3.6.7 7.74-7.69 m 4 128.66, 130.36 1.8 8.29 d (J = 7.4Hz) 2 125.33 9.11 8.03 s 2 110.96 o-Ph 7.99 d (J = 7.4Hz) 2 127.03 Position displacement Multi- Inten- displacement chemical * H chemical plicity 13C m-Ph 7.54 t (J = 7.4Hz) 2 129.47 p-Ph 7.46 t (J = 7.4Hz) 1 130.80 Styrene polymerizations In a 300 ml Schlenk vessel, 50 ml of toluene, 5 ml of styrene which was freshly distilled over calcium hydride and 6 ml of methyl aluminoxane (MAO): 1.69 M were heated to the desired polymerization temperature. toluene and stirred for 10 minutes. The titanium catalyst (2.5 μmol, 1 ml of a 2.5 mM solution in toluene) was added via syringe and the reaction solution was stirred for 10 to 20 minutes (Al: i = 4000: 1). The mixture was hydrolyzed by the addition of 10% HCl in methanol, the precipitated polystyrene was filtered off, washed with additional methanol and dried overnight at 100 ° C. Atactic material was removed by Soxhlett extraction with 2-butanone for 24 hours. The polymer was again dried overnight at 100 ° C and weighed to determine the syndiotactic content. The polymerization results are illustrated in the following table.

Table Polymerization of styrene using various metallocene / methyl aluminoxane catalysts. fifteen 2) A = activity [X] 107g of polystyrene / (mol of Ti per mole of styrene per hour)] 3) Syndiotacticity [weight percent of insoluble material in 2-butanone] 4) molecular weight (weight average) [per 104] determined by GPC ^ melting point [° C] determined by DSC ^ polymerization temperature

Claims (7)

1. KEIVINDICATIONS 1.- Process for preparing polymers based on monomers having a C = C double bond by homopolymerization or copolymerization of these monomers in the presence of a catalyst system comprising a metallocene complex A) and a compound B) capable of forming metallocene ions , and if desired an organometallic compound of the main group I, II or III of the Periodic Table of Elements C), wherein the metallocene complex A) used is a compound of the formula (I) wherein the substituents and indices have the following meanings: R1 to R11 are hydrogen, alkyl having 1 to 10 carbon atoms, cycloalkyl with 5 to 7 members which in turn can contain alkyl groups with 1 to 6 carbon atoms as substituents, aryl with 6 to 15 carbon atoms or arylalkyl, wherein two adjacent radicals R1 to R8 together can form a cyclic group having from 4 to 15 carbon atoms or Si (R12) 3, wherein R12 is alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms or cycloalkyl with 3 to 10 carbon atoms, M is a metal of transition groups III to VI of the Periodic Table of the Elements or a metal of the lanthanide series, X are identical or different and are hydrogen, halogen, alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkoxy with 1 to 10 carbon atoms or aryloxy with 6 to 15 carbon atoms and n is 1, 2, 3, 4 or 5, where n corresponds to the valence of M minus 1. 2.- Procedure for preparing polymers of conformity with claim 1, characterized in that the polymers are partially crystalline, have syndiotactic structural units and the monomers used are vinyl aromatic compounds of the formula (II)
2. (II), wherein the substituents and indices have the following meanings: R13 is hydrogen or alkyl having 1 to 4 carbon atoms, R14 to R18 independently of one another are hydrogen, alkyl having 1 to 2 carbon atoms, aryl having 6 to 18 carbon atoms , halogen or 2 adjacent radicals together form a cyclic group having 4 to 15 carbon atoms, and if desired additionally alkenes with 2 to 20 carbon atoms or cycloalkenes with 3 to 20 carbon atoms.
3. 3. A catalyst system that is suitable for polymerizing monomers having a C = C double bond and comprises as active constituents A) a metallocene complex of the formula (I) wherein the substituents and indices have the following meanings: R1 to R11 are hydrogen, alkyl with 1 to 10 carbon atoms, cycloalkyl with 5 to 7 members that at their it may contain alkyl groups having 1 to 6 carbon atoms as substituents, aryl with 6 to 15 carbon atoms or arylalkyl, wherein two adjacent radicals R1 to R8 together can form a cyclic group having from 4 to 15 carbon atoms or Si (R12) 3, wherein R12 is alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms or cycloalkyl with 3 to 10 carbon atoms, M is a metal of transition groups III to VI of the Periodic Table of the Elements or a metal of the lanthanide series, X are identical or different and are hydrogen, halogen, alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkoxy with 1 to 10 carbon atoms carbon or aryloxy with 6 to 15 carbon atoms, and n is 1, 2, 3, 4 or 5, where n corresponds to the valence of M minus 1, B) a compound capable of forming metallocene ions and, if desired, C ) an organometallic compound of the main groups I, II or III of the Periodic Table of the Elements.
4. 4. - Catalyst system according to claim 3, characterized in that M is a metal of the transition group IV of the Periodic Table of the Elements.
5. 5. A metallocene complex of the formula (I) wherein the substituents and indices have the following meanings: R1 to R11 on hydrogen, alkyl having 1 to 10 carbon atoms, cycloalkyl with 5 to 7 members which in turn can contain alkyl groups with 1 to 6 carbon atoms as substituents, aryl with 6 to 15 carbon atoms or arylalkyl, wherein two adjacent radicals R1 to R8 together can form a cyclic group having 4 to 15 carbon atoms or Si (R12) 3, wherein R 1 2 s alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms or cycloalkyl with 3 to 10 carbon atoms, M is a metal of transition groups III to VI of the Periodic Table of the Elements or a metal of the series lanthanides, X are identical or different and are hydrogen, halogen, alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkoxy with 1 to 10 carbon atoms or aryloxy with 6 to 15 carbon atoms and n is 1, 2, 3, 4 or 5, where n corresponds to the valence of M minus 1.
6. 6. - Cyclopenta [I] phenanthrene titanium trichloride, 2-methylcyclopenta [I] phenanthrene titanium trichloride and 2-phenyl-cyclopenta [I] phenanthrene titanium trichloride. 1 . - A monomer-based polymer having a C = C double bond which is obtained by homopolymerization or copolymerization of these monomers in the presence of a catalyst system comprising, as active constituents, a metallocene complex A) and a compound B) capable of forming metallocene ions and if desired an organometallic compound of the main groups I, II or III of the Periodic Table of Elements C) wherein the metallocene complex A) used is a compound of the formula (I): wherein the substituents and indices have the following meanings: R1 to R11 on hydrogen, alkyl with 1 to 10 carbon atoms, cycloalkyl with 5 to 7 members which in turn may contain alkyl groups with 1 to 6 carbon atoms; carbon as substituents, aryl with 6 to 15 carbon atoms or arylalkyl, wherein two adjacent radicals R1 to R8 together can form a cyclic group having from 4 to 15 carbon atoms or Si (R12) 3, wherein R12 s alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms or cycloalkyl with 3 to 10 carbon atoms, M is a metal of transition groups III to VI of the Periodic Table of the Elements or a metal of the Lanthanide series, X are identical or different and are hydrogen, halogen, alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkoxy with 1 to 10 carbon atoms or aryloxy with 6 to 15 carbon atoms and n is 1, 2, 3, 4 or 5, where n corresponds to the valence of M minus 1. 8. A fiber, film or molded part comprising a polymer according to claim
7. 7. 9.- The use of a metallocene complex (I) according to claim 5 or 6, as a component in catalyst systems is or as a catalyst. PURPOSE OF THE INVENTION In a process for preparing polymers based on monomers having a C = C double bond by homopolymerization or copolymerization of these monomers in the presence of a catalyst system, comprising a metallocene complex A) and a compound B) capable of forming metallocene ions, and if desired an organometallic compound of the major groups I, II or III of the Periodic Table of Elements C), the metallocene complex A) employed is a compound of the formula (I) wherein the substituents and indices have the following meanings: R1 to R11 are hydrogen, alkyl having 1 to 10 carbon atoms, cycloalkyl with 5 to 7 members which in turn can contain alkyl groups with 1 to 6 carbon atoms as substituents, aryl with 6 to 15 carbon atoms or arylalkyl, wherein two adjacent radicals R1 to R8 together can form a cyclic group having from 4 to 15 carbon atoms or Si (R12) 3, wherein R12 is alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon or cycloalkyl atoms with 3 to 10 carbon atoms, M is a metal of transition groups III to VI of the Periodic Table of the Elements or a metal of the lanthanide series, X are identical or different and are hydrogen, halogen, alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkoxy with 1 to 10 carbon atoms or aryloxy with 6 to 15 carbon atoms n is 1, 2, 3, 4 or 5, where n corresponds to the valence of M minus 1. SUMMARY OF THE INVENTION In a process for preparing polymers based on monomers having a C = C double bond by homopolymerization or copolymerization of these monomers in the presence of a catalyst system, comprising a metallocene complex A) and a compound B) capable of forming metallocene ions, and if desired an organometallic compound of the major groups I, II or III of the Periodic Table of Elements C), the metallocene complex A) employed is a compound of the formula (I) wherein the substituents and indices have the following meanings: R1 to R11 are hydrogen, alkyl having 1 to 10 carbon atoms, cycloalkyl with 5 to 7 members which in turn can contain alkyl groups with 1 to 6 carbon atoms as substituents, aryl with 6 to 15 carbon atoms or arylalkyl, wherein two adjacent radicals R1 to R8 together can form a cyclic group having from 4 to 15 carbon atoms or Si (R12) 3 / n of R12 is alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon or cycloalkyl atoms with 3 to 10 carbon atoms, M is a metal of transition groups III to VI of the Periodic Table of the Elements or a metal of the lanthanide series, X are identical or different and are hydrogen, halogen, alkyl with 1 to 10 carbon atoms, aryl with 6 to 15 carbon atoms, alkoxy with 1 to 10 carbon atoms or aryloxy with 6 to 15 carbon atoms and n is 1, 2, 3, 4 or 5, where n corresponds to the valence of M minus 1.