WO2000022010A1 - Polyolefin nanocomposites - Google Patents

Abstract

The invention relates to a method for producing polyolefin nanocomposites. According to said method, C2- to C20-alk-1-enes and/or vinylaromatic compounds are polymerised in the presence of a dispersion of one or more layered silicates, using a transition metal catalyst.

Description

Polyolefin nanocomposite

description

The present invention relates to a method for producing polyolefin nanocomposites. The invention further relates to the polyolefin nanocomposites obtainable by this process and their use for the production of films, moldings and fibers.

Thermoplastic nanocomposites based on polyamides, polyesters or polystyrenes are known. These thermoplastic materials are characterized by due to good rigidity with good toughness behavior at the same time.

To improve the physicochemical properties of polymers, clay minerals were used early on as reinforcing agents (see H.K.G. Theng in "Formation and Properties of Clay-Polymer Complexes", Elsevier, Amsterdam,

1979). The clay mineral was radically polymerized in the presence of vinyl onomers for compatibility with the polymer matrix. However, with this type of impregnation there is no effective penetration of the layer structure of the clay mineral with the polymer material, which is why the connection between the polymer and the inorganic filler material is unsatisfactory. Satisfactory results were only achieved with the polycondensation of caprolactone in the presence of clay mineral / aminolauryl acid or clay mineral / aminocaproic acid intercalates (cf. Fukushima et al., Clay Miner. 1988, 23, page 27).

According to US 529 006, ethene can be polymerized in the presence of a Ziegler-Natta catalyst which has been applied to the surface of an inorganic filler. The filling material also takes on the function of a carrier. A polymer material with homogeneously distributed filling particles is obtained. If a clay mineral is used as a filler, it must first be dehydrated under oxidizing conditions at high temperatures. However, catalytically active transition metal complex compounds are generally not sufficiently stable to be applied or bonded to the filler materials disclosed in US 529 006.

By adding specially pretreated montmorillonite, Yano et al., J. Polym. Be. A, polym. Chem., 1993, 31,

Pages 2493 - 2498, polyimides with a low coefficient of thermal expansion and good gas barrier properties put. In a multi-stage process, an intercalate of montmorillonite and the ammonium salt of dodecylamine is first formed. The layered silicate delaminated in this way can then be processed in the form of a dispersion with a polyimide solution to give what is known as a 5-polyimide-mineral hybrid. In this way, polyimide films with a nanocomposite structure can be produced.

Usuki et al., J. Appl. Polym. Sei., 1997, Vol. 63, pages 137-10139, found that montmorillonite cannot be incorporated into polypropylene in the manner described above. Intercalates of distearyldimethylammonium ions and montmorillonite tend to aggregate in the relatively non-polar polymer matrix of polypropylene. It is only by adding olefin oligomers with telechelic hydroxyl groups that the treated layered silicates can be dispersed in the polymer on a nanoscale. However, layered silicate aggregates cannot be completely avoided in this way either.

20 In a further developed process for the production of polypropylene-mineral hybrids, Kawasumi et al., Macromol., 1997, 30, pages 6333-6338 used a propylene oligomer modified with maleic anhydride, in deviation from the mediator component described above. A powdery dry mix

25 made of montmorillonite, polypropylene and maleic anhydride-modified polypropylene intercalated with stearylammonium ions provides a polymer mixture with a nanocomposite structure in the melt. In the present case, however, nanocomposites can be made without the addition of maleic anhydride-modified propylene oligomer

30 do not realize.

From a solution of montmorillonite and HD polyethylene delaminated with dodecylammonium ions in a mixture of benzonitrile and xylene, Jeon et al. , Polym. Bull, 1998, pages 107 -

35 113, polyethylene nanocomposites precipitate by adding tetrahydrofuran. However, the authors already indicate that the dispersibility of the layered silicates in the polymer matrix could still be improved. They suggest grafting polyethylene chains onto the silicate layers.

40

Since polyolefins as non-polar polymers naturally have no affinity for organic and inorganic compounds with polar groups, special efforts must be made regularly, for example to ensure homogeneous mixing of polyolefins

45 and layered silicates. Accordingly, polyolefin nanocomposites can only be prepared in a very complex manner. Although layered silicates are diverse to improve and round off the Properties profile of polymers are used, so far there has been no process to make nanocomposites based on polyolefins, especially on an industrial scale, accessible.

In addition, in particular in the large-scale production of polyolefins, efforts are made to prevent or keep reactor fouling as low as possible. Often, however, this cannot be ensured.

The present invention was therefore based on the object of making a simple, versatile and inexpensive process for the production of nanocomposites based on polyolefins available which does not rely on the use of a large number of specifically modified additive components and which is the prerequisite for large-scale industrial applications Fulfills.

Accordingly, a process for the preparation of polyolefin nanocomposites has been found in which C ₂ - to C o-alk-l-enes and / or vinylaromatic compounds are polymerized in the presence of a dispersion of one or more phyllosilicates in a transition-metal-catalyzed manner.

Furthermore, the polyolefin nanocomposites obtainable by this process and their use for the production of films, moldings and fibers have been found.

Suitable layered silicates which can be used in the process according to the invention include natural as well as synthetic layered silicates in untreated and treated form. The layered silicates treated include those with

Acids, and those which have been treated with suitable organic hydrophobizing agents. Preference is given to onium ions and onium treated layer silicates used ie de ^¬ laminated or intercalated phyllosilicates.

Layered silicates in the sense of the present invention are generally understood to mean those silicates in which the SiO 3 tetrahedra are connected in two-dimensional infinite networks (the empirical formula for the anion is (Si ₂ θ ₅ ^{2 "} ) _n ). The individual layers are ion through the lying between them Kat ^¬ connected to each other, wherein, potassium, present mostly in the course coming before ^¬ layer silicates as sodium cations magnesium, aluminum and / or calcium.

The natural sodium silicates natronsilite, makatite, magadiite, kenyaite, kanemite, revolite and grumantite are, for example, suitable as layered silicates. Bleaching earths are particularly suitable clay-like layered silicates such as talc, mica, kaolinite and

Bentonite. In particular, water-containing aluminum and / or magnesium silicate bleaching earths such as montmorillonite are also used.

Furthermore, smectite, illite, sepiolite, palygorskite, muscovitite, allevardite, amesite, hectorite, fluorhectorite, saponite, betellite, nontronite, stevensite, vermiculite, fluorvermiculite and

Halloysite called. Among the synthetic layered silicates, the fluorine-containing synthetic mica types should be emphasized.

A description of suitable layered silicates can be found e.g. with G. Lagaly, Progr. Colloid & Polym. Be. 1994, 95, pages 61-72.

Layered silicates of the bentonite type such as Optigel® from Südchemie, Munich, for example, can be used as untreated layered silicates. The use of synthetic layered silicates e.g. SOMASIF® ME100 from CO-OP Ltd., Japan, is possible.

Layered silicates treated within the meaning of the present invention are to be understood to mean, inter alia, those silicates which have been pretreated with an acid, for example a mineral acid such as hydrochloric acid or sulfuric acid. This includes, for example, the commercially available "Catalyst K 10" bleaching earth from Süd-Chemie, Munich, which is a mineral compound modified by treatment with hydrochloric acid and based on calcium montmorillonite. In this context, the layered silicates that come from natural bentonites and fall under the brand TONSIL ^® (Süd-Chemie) should also be mentioned.

Furthermore, treated layered silicates are to be understood in particular as delaminated layered silicates. Delaminated or intercalated layered silicates for the purposes of the present invention include silicates in which the layer spacings have been widened by reaction with organic hydrophobizing agents before the polyolefin nanocomposites are produced. The ^¬ like layer silicates also have a reduced polarity.

Suitable as water repellents are e.g. Onium ions and onium salts.

The cations of the layered silicates are replaced by these organic water repellents, the desired layer spacings being able to be set via the type of organic residue. The metal ions can be exchanged completely or partially. A complete exchange of the metal ions is preferred. The amount of exchangeable metal ions is usually given in milliequivalents (meq) per 100 g layered silicate and is referred to as the ion exchange capacity.

Layered silicates with a cation exchange capacity of at least 50, preferably 80 to 130 meq / 100 g are preferred. Suitable organic water repellents are derived from oxonium, ammonium, phosphonium and sulfonium ions, which can carry one or more organic radicals.

Suitable hydrophobicizing agents are those of the general formula V and / or VI:

V VI where the substituents have the following meaning:

R ^a , R ^b , R ^c , R ^d independently of one another are hydrogen, a straight-chain or branched, saturated or unsaturated hydrocarbon radical having 1 to 40, preferably 1 to 20, carbon atoms or 2 of the radicals, in particular to form a heterocyclic radical Rest with 5 to 10 carbon atoms,

Q phosphorus or nitrogen,

Oxygen or sulfur,

W an anion.

Hydrophobing agents also include those compounds V or VI ^{which have} an alkyl or alkylene chain with a terminal double bond as the radical R ^a to R ^d , for example an ω-decenyl, ω-undecenyl, ω-dodecenyl, stearyl or ω-octadecenyl group. Polyolefin chains can optionally be polymerized directly onto the layered silicate structure via a delaminated layered silicate which has the stated substituents. Suitable anions (W) are derived from proton-providing acids, in particular mineral acids, halides such as

Chloride, bromide, fluoride or iodide as well as sulfate, sulfonate,

Phosphate, phosphonate, phosphite and carboxylate and especially acetate are preferred.

Suitable phosphonium include for example Dicosyltrime- thylphosphonium, Hexatriacontyltricyclohexylphosphonium, octadecyl cyltriethylphosphonium, Dicosyltriisobutylphosphonium, methyl tri - nonylphosphonium, Ethyltrihexadecylphosphonium, Dimethyldidecyl- phosphonium, Diethyldioctadecylphosphonium, Octadecyldiethylal - lylphosphonium, Trioctylvinylbenzylphosphonium, Dioctydecylethyl - hydroxyethylphosphonium, Docosyldiethyldichlorbenzylphosphonium, Octylnonyldecylpropargylphosphonium, Triisobutylperfluordecyl - phosphonium, Eicosyltrihydroxymethylphosphonium, Triacontyltris - called cyanethylphosphonium and bis - trioctylethylene diphosphonium.

Alkylammonium ions are particularly suitable, e.g. Butylammonium-, Hexylammonium-, Octylam onium-, Hexadecylammonium-, Octadecylammonium-, Laurylammonium-, MyriStylammonium, Palmity- lammonium-, Stearylammonium-, Pyridinium-, Octadecylammonium-, Monomethyloctadecyl- dammonium- ammonium-, Ammonium-,

Other suitable water repellents include in WO 93/4118, WO 93/4117, EP-A 398 551 and DE-A 36 32 865.

Dimethylstearylbenzylammonium chloride or dimethyldistearylammonium chloride is particularly preferably used as the hydrophobizing agent.

The product Tixogel ^® (Süd-Chemie) may be mentioned as a commercially available, particularly suitable treated sheet silicate. These include layered silicates from the class of the bentonites which are swollen with dimethylstearylbenzylammonium chloride.

For delamination, the untreated layered silicates are generally reacted with the hydrophobizing agent in a suspension. The preferred suspending agent is water, optionally in a mixture with alcohols, in particular lower alcohols having 1 to 3 carbon atoms. It may be advantageous to add a hydrocarbon, for example heptane, to the aqueous medium. since the hydrophobicized layered silicates are usually more compatible with these hydrocarbons than with water.

Other suitable examples of suspending agents are ketones and hydrocarbons. A water-miscible solvent is usually preferred. When the hydrophobizing agent is added to the layered silicate, an ion exchange takes place, as a result of which the layered silicate usually becomes more hydrophobic and precipitates out of the solution. The metal salt formed as a by-product of the ion exchange is preferably water-soluble, so that the hydrophobic layered silicate as a crystalline solid by e.g. Filtering can be separated.

The ion exchange is largely independent of the reaction temperature. The temperature is preferably above the crystallization point of the medium and below its boiling point. In aqueous systems, the temperature is between 0 and 100 ° C, preferably between room temperature (about 20 ° C) and 95 ° C.

After the hydrophobization, the layered silicates have a layer spacing of 5 to 100 Å, preferably 5 to 50 Å and in particular 8 to 40 Å. The layer spacing usually means the distance from the lower layer edge of the upper layer to the upper layer edge of the lower layer. The length of the leaflets is usually up to 2000 Å, preferably up to 1500 Å.

The untreated and treated layered silicates described above are usually used in the form of a dispersion in the process according to the invention. As

Dispersing agents are inert non-polar aliphatic and aromatic liquids. Suitable are, for example, aliphatic hydrocarbons such as heptane or i-octane, aromatic hydrocarbons such as benzene, toluene or xylene, halogenated hydrocarbons such as chloroform or dichloromethane or mixtures of the compounds mentioned. The dispersions can be obtained by intensive mixing of layered silicate and dispersant. Stirrer speeds in the range from 500 to 5000 rpm are generally sufficient for this. This is advantageously done at stirring speeds in the range from 5000 to 13000 rpm, particularly preferably at 10000 rpm, over a period of 1 minute to 3 hours, preferably over a period of 10 minutes to 1 hour. Dispersion is particularly preferred under shear conditions. The desired dispersion conditions can be set, for example, with the Ultra-Turrax T25 from Jahnke and Kunkel. The layered silicate dispersions can, for example, be carried out directly in the polymerization vessel produce. However, they can also be prepared separately and then either placed in the reaction vessel or added at any time before the catalyst compounds are added. The layered silicates are usually present in the dispersions in concentrations in the range from 1 to 40 g / 1, preferably in the range from 3 to 35 and particularly preferably in the range from 6 to 30 g / 1. The dispersions obtained are stable and clear. The particle sizes of the layered silicates in the dispersions obtained are preferably below 100 μm, preferably in a range from 10 μm to 100 nm. Even in the case of longer standing times, no layered silicate precipitates out of the dispersions.

With the process according to the invention, a wide variety of C ₂ - to C ₂ o-alk-1-enes, in particular C ₂ - to C ₂ -alk-1-enes, can be polymerized to polyolefins (co). Come alongside ethene or propene

Alk-1-enes such as 1-butene, 1-pentene, 1-hexene, 1-heptene or 1-octene and also 1-decene or 1-dodecene are possible. Of course, alk-1-enes also include aromatic monomers with a vinyl double bond, ie vinylaromatic compounds such as styrene or α-methylstyrene. It is also possible to use any mixtures of C ₂ -C 10 -alk-1-enes or mixtures of alk-1-enes with vinylaromatic compounds, for example styrene with ethene or higher alk-1-enes such as but-1-ene or oct -l-en, can be used. Ethene or propene or a mixture thereof is preferably used. The process according to the invention for the production of polyolefin nanocomposites allows access to homopolymers such as polyethylene or homopropylene as well as to copolymers, for example poly (ethene-co-but-1-ene).

In the process according to the invention, alk-1-enes or the vinylaromatic compounds are polymerized with the aid of transition metal complexes in the presence of the dispersions described according to a coordinative mechanism. In principle, all transition metal compounds that polymerize alk-1-enes to polyolefins can be used (see also W. Kaminsky and M. Arndt, Adrances in Polymer Science, 1997, 127, pp. 143-187, and H. -H. Brintzinger , D. Fischer, R. Mülhaupt, B. Rieger, RM Waymouth, Angew. Chem., 1995, 107, p. 1255 ff.).

In a preferred embodiment, C - to C ₂ o-alk-1-enes and / or vinylaromatic compounds in the presence of a dispersion of one or more phyllosilicates in a non-polar aliphatic or aromatic dispersant and a transition metal compound of the general formula (Ia) or (Ib)

(Ia) (Ib)

in which the substituents and indices have the following meaning:

R ¹ 'to R ⁴ ' is hydrogen, -C ~ to -Cι ₀ alkyl, partially or per- halogenated Cι ~ to Cio-alkyl, C - to Cirj-cycloalkyl, C ₆ - to Cι-aryl, with functional groups the basis of the elements from groups IVA,

VA, VIA and VIIA of the periodic table of the elements partially or per-substituted C ₆ - to -C ₄ aryl, C - to Cχ heteroaryl, alkylaryl with 1 to 10 carbon atoms in the alkyl and 6 to 14 carbon atoms in the aryl radical or Si (R ⁶ ') ₃ , wherein R ¹ ' and R ⁴ 'are not hydrogen, or

R ¹ 'and R ² ' together with C ^a and N ^a or R ³ 'and R ⁴ ' together with C ^b and N ^{b form} a five-, six- or seven-membered aromatic or aliphatic, substituted or unsubstituted heterocycle, or

R ² 'and R ³ ' together with C ^a and C ^{b form} a five-, six- or seven-membered aliphatic or aromatic, substituted or unsubstituted carbo- or heterocycle,

R ⁵ 'is hydrogen, -C ~ to Cio-alkyl, C ₃ - to Cio-cycloalkyl, C ₆ - to Cι-aryl, alkylaryl with 1 to 10 carbon atoms in the alkyl and 6 to 14 carbon atoms in the aryl radical or Si (R ⁶ ') ₃ ,

R6 '-C ~ to Cio-alkyl, C ₃ - to Cio-cycloalkyl, C ₆ - to C- aryl, alkylaryl with 1 to 10 C atoms in the alkyl and 6 to 14 C atoms in the aryl radical, m 0 or 1,

M 'is an element from Group VIIIB of the Periodic Table of the Elements,

Q 'acetonitrile, benzonitrile, a linear alkyl ester, a linear or cyclic aliphatic ether, dimethyl sulfoxide, dimethylformamide, hexamethylphosphoric triamide or halides,

T 'chloride, bromide, iodide or a Cι ~ to C ₂₀ alkyl, which has no hydrogen atoms in the ß position to the metal center M', and optionally has a Ci- to C -alkyl ester end group or a nitrile end group, or Q 'and T 'together form a C ₃ alkylene chain with a linear C ~ to C alkyl ester or a nitrile end group,

A 'a non- or poorly coordinating anion and

n 0, 1, 2 or 3

polymerized.

In the process according to the invention, transition metal compounds (la) or (Ib) are used which are combined with bidentate chelate ligands of the general formula (IVa) or (IVb)

RM. R ³ '

M ^a (C (R ⁵ J ₂ ) _ι iϊ— C ^b ^

[IVa)

Ri - - N ^a N ^b - - R ⁴ '

R ³ '

R ²

M ^a (c (R ⁵ J ₂ ) sr- c ^b - - R ³ '

(ivb), Rl - - N ^a p - - R ⁴

R ⁴ '

are complexed in which

R ¹ 'and R ⁴ ' independently of one another are hydrogen, straight-chain or branched C ₁ -C 1 -alkyl, preferably C ₁ -C ₆ -alkyl, such as methyl, ethyl, n-propyl, i-pro- pyl, n-butyl, i-butyl, t-butyl, partially or per-halogenated Ci- to Cio-alkyl, preferably Ci- to C _ß- alkyl, such as trifluoro or trichloromethyl or 2, 2, 2-trifluoroethyl, substituted or unsubstituted C ₃ - to Cio-cycloalkyl, preferably C ₃ - bis

Ce-cycloalkyl, such as cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl or 4-t-butylcyclohexyl, C ₆ - to C 1 -aryl, preferably C_ to C 1 -aryl, such as phenyl or naphthyl, especially phenyl, with functional groups based on the elements from groups IVA, VA, VIA and VIIA of the Periodic Table of elements partially or persubstituted CQ - to Cι ₄ -aryl, preferably C ₆ - to Cio-aryl, with straight-chain or branched Cι ~ to CIO Alkyl, preferably C ₁ -C ₆ -alkyl, such as methyl,

Ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, partially or perhalogenated C ₁ -C ₄ -alkyl, preferably C ₁ -C ₆ -alkyl, such as trifluoromethyl or trichloromethyl or 2 , 2, 2-trifluoroethyl, triorganosilyl, for example trimethyl,

Triethyl-, tri-t-butyl-, triphenyl- or t-butyl-di-phenylsilyl, amino, for example NH ₂ , dimethylamino, di-i-propylamino, di-n-butylamino, diphenylamino or dibenzylamino, Cι ~ to Cio- Alkoxy, preferably C ₁ to C ₆ alkoxy, for example methoxy, ethoxy, n-propoxy, i-propoxy, t-butoxy or halogen, for example fluoride, chloride, bromide or iodide; C _ to C heteroaryl, preferably C to Cg heteroaryl, such as pyridyl, pyrimidyl, quinolyl or isoquinolyl, alkylaryl having 1 to 10 C atoms, preferably 1 to 6 C atoms in the alkyl and 6 to 14 C- Represent atoms, preferably 6 to 10 carbon atoms in the aryl radical, such as benzyl, or Si (R ⁶ ') ₃ , where R ¹ ' and R ⁴ 'are not hydrogen, or

R ¹ 'and R ² ' together with C ^a and N ^a or R ³ 'and R ⁴ ' together with C ^b and N ^{b form} a five-, six- or seven-membered aromatic or aliphatic, substituted or unsubstituted heterocycle, or

R ² 'and R ³ ' together with C ^a and C ^{b are} a five-, six- or seven-membered aliphatic or aromatic, substituted or unsubstituted carbo- or

Form heterocycle, R ⁵ 'independently of one another is hydrogen, straight-chain or branched C ₁ -C 10 -alkyl, preferably C ₁ -C ₆ -alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-Butyl, especially methyl, substituted or unsubstituted C ₃ - to Cio-cycloalkyl, preferably C ₃ - to Cg-cycloalkyl, such as cyclopropyl, cyclopentyl, cyclhexyl, 1-methylcyclohexyl or 4-t-butylcyclohexyl, especially cyclohexyl, C ₆ - to -C aryl, preferably C ₆ ~ to Cio-aryl, such as phenyl or naphthyl, especially phenyl, alkylaryl with 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms in the alkyl and 6 to 14 carbon atoms , preferably 6 to 10 carbon atoms in the aryl radical, such as benzyl or Si (R ⁶ ') ₃ , particularly preferably represent hydrogen or methyl,

R ⁶ 'independently of one another straight-chain or branched Ci to Cio alkyl, preferably Ci to C ₆ alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, especially methyl or t- Butyl, C ₃ - bis

Cio-cycloalkyl, preferably C ₃ - to C ₆ -cycloalkyl, such as cyclopropyl, cyclopentyl or cyclohexyl, in particular cyclohexyl, substituted or unsubstituted C ₆ to C 1 aryl, preferably C ₆ to Cio aryl, such as phenyl or naphthyl, in particular phenyl, alkylaryl having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms in the alkyl and 6 to 14 carbon atoms, preferably 6 to 10 carbon atoms in the aryl radical, in particular benzyl and

m is 0 or 1, in particular 0.

As described, in the ligand compounds (IVa) and (IVb) the vicinal residues R ¹ 'and R ² ' together with N ^a and C ^a or the vicinal residues R ³ 'and R ⁴ ' together with N ^b and C ^b or with P and C ^{b form} a substituted or unsubstituted five-, six- or seven-membered aromatic or aliphatic heterocycle. A five- or six-membered aliphatic ring system, for example based on pyrrolidyl, piperidyl or oxazolyl, a five- or six-membered aromatic ring system, for example based on pyrazolyl or pyridyl, or a fused aromatic heterocycle such as quinolyl or Isoquinolyl. The ring systems listed can be both unsubstituted and substituted, for example with -CC alkyl radicals such as methyl, ethyl, i-propyl or t-butyl, partially or perhalogenated alkyl radicals such as trifluoromethyl or 2,2, 2-trifluoroethyl, aryl radicals such as phenyl or naphthyl , substi- tuated aryl residues such as tolyl or 2- or 4-trifluoromethylphenyl, alkoxy residues such as methoxy, ethoxy, i-propoxy or t-butoxy, amino residues such as dimethylamino, diphenylamino or dibenzylamino, triorganosilyl residues such as trimethyl, tri-i- propyl, tri-n-butyl, triphenyl or t-butyl-di-phenylsilyl or halogen such as

Fluoride, chloride, bromide or iodide are present. Six-membered aromatic, substituted or unsubstituted are preferred

Heterocycles. These heterocycles can be substituted, for example, with alkyl groups, for example C ₁ -C ₄ alkyl groups such as methyl, or fused with aromatic ring systems such as benzene.

Among the radicals R ² 'and R ³ ' are hydrogen, methyl, ethyl, i-propyl, t-butyl, methoxy, ethoxy, i-propoxy, t-butoxy, trifluoromethyl, phenyl, naphthyl, tolyl, 2-i-propylphenyl , 2-t-butylphenyl, 2, 6-di-i-propylphenyl, 2-trifluoromethylphenyl, 4-methoxyphenyl, pyridyl or benzyl and in particular hydrogen, methyl, ethyl, i-propyl or t-butyl are preferred. Ligand compounds with these residues can be found in K. Vrieze and G. van Koten, Adv. Organomet. Chem., 1982, 21, pp. 151-239. The radicals R ² 'and R ³ ' together with C ^a and C ^{b are} preferably part of a phenanthrene or camphor system, as in J. Matei and T. Lixandru, Bul. Inst. Politeh. Iasi, 1967, 13, p. 245.

Particularly suitable radicals R ¹ 'and R ⁴ ' are those with sterically demanding aliphatic or aromatic groups such as t-butyl, neopentyl, cyclohexyl, substituted cyclohexyl such as 1-methylcyclohexyl or 4-t-butylcyclohexyl, phenyl, substituted phenyl such as 2- i-propylphenyl, 2-t-butylphenyl, 2, 6-di-i-propylphenyl, 2-trifluoromethylphenyl, 4-methoxyphenyl, pyridyl, pyrimidyl, quinolyl, isoquinolyl, benzyl or substituted or unsubstituted naphthyl such as 1- or 2- Naphthyl, cyclopropyl, cyclopentyl, cyclohexyl, 1-methylcyclohexyl, 4-t-butylcyclohexyl or ferrocenyl. Particularly preferred radicals are cyclohexyl, phenyl, 1- or 2-naphthyl, 2-i-propylphenyl, 2-t-butylphenyl, 2, 6-di-t-butylphenyl, 2, 6-dineopentylphenyl, 2, 6-di- i-propylphenyl or 2-trifluoromethylphenyl, in particular 2,6-di-i-propylphenyl. For compounds (IVb), phenyl is also particularly preferred as the radical R '.

Preferred ligands (IVa) and (IVb) are compounds of the formula (IVa). The ligands of the compounds (IVa) can have both C ₂ symmetry and be asymmetrical, ie differ in the radicals R ¹ ', R ² ' or R ³ ', R ⁴ '. Those with identical radicals R ¹ 'and R ⁴ ' are particularly preferred. Some preferred ligand compounds (IVa) are mentioned below as examples: Bis-N, N '- (2, 6-diisopropylphenyl) -1, 4-diaza-l, 3-butadiene,

Bis-N, N '- (2, 6-diisopropylphenyl) -1, 4-diaza-2, 3-dimethyl-l, 3-butadiene,

Bis-N, N'- (2,6-dimethylphenyl) -1,4-diaza-1,3-butadiene, bis-N, N'- (2,6-dimethylphenyl) -1,4-diaza-2, 3-dimethyl-l, 3-butadiene,

Bis-N, N '- (1-naphthyl) -1, 4-diaza-l, 3-butadiene and

Bis-N, N'- (l-naphthyl) -l, 4-diaza-2,3,3-dimethyl-1,3-butadiene.

The bidentate ligands (IVa) can e.g. made of glyoxal or

Diacetyl can be obtained by reaction with primary amines such as n-butylamine, i-butylamine, t-butylamine, cycolhexylamine, 2-trifluoromethylaniline, 2-isopropylaniline, 2-t-butylaniline, 1-naphthylamine or 2,6-diisopropylaniline (see also G. van Koten and K. Vrieze in Advances in Organometallic Chemistry, Vol. 21, pp. 152-234, Academic Press, 1982, New York).

Suitable metals M 'in (la) or (Ib) are all elements of group VIIIB of the periodic table, ie iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium or platinum. Nickel, rhodium, palladium or platinum are preferably used, nickel and palladium, in particular palladium, being particularly preferred. Iron and cobalt are generally present in the metal compounds (I) in two or three times positively charged, palladium, platinum and nickel in two positively charged and rhodium in three positively charged.

The radical T 'in (I) can be chloride, bromide, iodide and preferably a C 1 -C 8 -alkyl which has no hydrogen atoms in the β position to the metal center M'. If appropriate, the C ₁ -C ₂ -alkyl radical can have a C 1 -C ₄ -alkyl ester or a nitrile end group. Chloride and bromide are preferred as halides and methyl as the alkyl radical.

The rest Q 'can mean acetonitrile, benzonitrile or a linear or cyclic aliphatic ether such as diethyl ether, di-i-propyl ether or tetrahydrofuran, preferably diethyl ether. Q 'can also be a linear alkyl ester, preferably having 1 to 6 carbon atoms in the acid and 1 to 4 carbon atoms in the alcohol part, dimethyl sulfoxide, dimethylformamide or hexamethylphosphoric acid triamide and, in particular in the case of nickel complexes (la) or (Ib) also a halide, e.g. a bromide.

Furthermore, the radicals T 'and Q' together can represent a C ₃ -alkylene chain with a linear alkyl ester end group or with a nitrile end group. T 'and Q' preferably together form a - (CH ₂ CH ₂ CH ₂ C (0) OCH ₃ ) unit. T 'and Q' accordingly together with the metal center M 'represent a six-membered cycle.

For the complexes (la) and (Ib) of nickel (M '= Ni), preferably the nickel dihalide (n = 0), especially the nickel dibromide complexes, open-chain or cyclic alumoxane compounds, e.g. MAO (methylalumoxane solution in toluene, approx. 10% by weight) as activator additives. These oligomeric alumoxane compounds are usually prepared by reacting a solution of trialkylaluminum with water and include in EP-A 284 708 and US A 4,794,096.

According to the invention, a non-coordinating or poorly coordinating anion A 'is to be understood as those anions whose charge density at the anionic center is reduced due to electronegative residues and / or whose residues shield the anionic center sterically. Preferred anions A 'are borates such as B [C ₆ H ₃ (CF ₃ ) ₂ ] _ ^~ (tetra (3,5-bis (trifluoromethyl) phenyl) borate), B [C ₆ F ₅ ] ₄ ^~ , BF ₄ ^~ or SbF ₆ ^_ , A1F ₄ -, AsF ₆ -, PF ₆ -, CF ₃ S0 ₃ ", in particular B [C ₆ H ₃ (CF ₃ ) ₂ ] _ ^~ , SbF ₆ ^~ and PF ₆ ^~ . Suitable Anions and their preparation are described, for example, in SH Strauss, Chem. Rev. 1993, 93, pp. 927-942 and W. Beck and K. Sünkel, Chem. Rev. 1988, 88, pp. 1405-1421.

Preferred transition metal compounds are, for example

[Bis-N, N '- (2, 6-diisopropylphenyl) -1, 4-diaza-2, 3-dimethyl-1,3-butadiene] palladium-acetonitrile-methyl- (tetra (3, 5-bis- ( trifluoromethyl) phenyl) borate), [bis-N, N '- (2,6-diisopropylphenyl) -1,4-diaza-2,3-dimethyl-1,3-butadiene] palladium-diethylether-methyl- (tetra ( 3, 5-bis (trifluoromethyl) phenyl) borate), [bis-N, N'- (2,6-diisopropylphenyl) -1, 4-diaza-2, 3-dimethyl-1,3-butadiene] - palladium -h ¹ -0-methylcarboxypropyl- (tetra (3,5-bis- (trifluoromethyl) phenyl)) borate), [bis-N, N '- (2,6-diisopropylphenyl) -1,4-diaza-1, 3-butadiene] palladium-hA-O-methylcarboxypropyl- (tetra- (3,5-bis- (trifluoromethyl) phenyl) borate) or [bis-N, '- (1-naphthyl) -1, 4-diaza-2 , 3-dimethyl-l, 3-butadiene] palladium-h ⁱ -O-methylcarboxypropyl- (tetra (3, 5-bis (trifluoromethyl) phenyl)) borate).

The transition metal compounds (la) and (Ib) are e.g. accessible from such complexes in which Q 'is replaced by a halide, in particular by a chloride. Examples include [bis-N, N '- (2,6-diisopropylphenyl) -1, 4-diaza-2,3-dimethyl-1,3-butadiene] palladium-methyl chloride or [bis-N, N' - (2, 6-diisopropylphenyl) -1, 4-diaza-l, 3-butadiene] alladium-methyl-choride.

As a rule, these complexes are treated in the presence of acetonitrile, benzonitrile, dimethyl sulfoxide, dimethylformamide, hexa- methylphosphoric acid triamide or a linear or cyclic ether such as diethyl ether with an alkali metal or silver salt (M '') ⁺ A ' ^~ with A' in the designated meaning of a non- or poorly coordinating anion and M '' eg in the meaning of sodium, Potassium, lithium, cesium or silver, for example sodium (tetra (3,5-bis (trifluoromethyl) phenyl) borate) or silver hexafluoroantimonate. One example is the one in Mecking et al. , J. Am. Chem. Soc. 1998, 120, pp. 888-899 referenced production. The starting compound in which Q 'is replaced by a halide can be obtained by treating a corresponding cyclo-ocadiene complex with a ligand of the general formula (IVa) or (IVb) in a non-coordinating solvent such as dichloromethane. Such production processes are known to the person skilled in the art and are described, for example, in Johnson et al., J. Am. Chem. Soc. 1995, 117, p. 6414 and JH Groen et al.,

Organometallics, 1997, 17, p. 68. For the preparation of the cyclooctadiene complexes, e.g. on H. Tom Dieck et al., Z. Naturforschung, 1981, 36b, p. 823 and D. Drew and J.R. Doyle, Inorganic Synthesis, 1990, 28, p. 348 and to the German patent application 19730867.8.

The transition metal complexes (Ia) and (Ib) can also be obtained starting from compounds such as (TMEDA) MMe ₂ (TMEDA = N, N, N ','-Tetra-methylethylenediamine; Me = methyl). The (TMEDA) complexes are, for example, according to a specification by de Graaf et al., Rec. Trav. Chim. Pay-Bas, 1988, 107, 299 accessible from the corresponding dichloride complexes.

The polymerizations with the metal complexes (I) usually take place at a pressure in the range from 1 to 100 bar, preferably from 1 to 70 bar and particularly preferably from 1 to 60 bar.

The concentration of transition metal compound (la) or (Ib) is generally in the range of 10 ^{~ 6} to 0.1, preferably in the range of 10 ^{~ 5} to 10 ^{~ 2} and particularly preferably in the range of 5 x 10 ^{~ 5} to 10 ^{~ 3} mol / 1 set:

The initial concentration of the olefinically unsaturated monomers in the reaction solution is generally in the range from 10 ^{~ 5} to 15 mol / 1, preferably from 10 ^{~ 2} to 12 mol / 1 and particularly preferably from 10 ^"1 to 11 mol / 1.

In a further preferred embodiment, the monomers are in the presence of the dispersion described and a metallocene complex of the general formula (II)

in which the substituents have the following meaning:

M titanium, zirconium, hafnium, vanadium, niobium or

Tantalum

X is hydrogen, -C ~ to Cio-alkyl, C ₆ - to Cι ₅ -aryl,

Alkylaryl with 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, -OR ⁶ or -NR ⁶ R ⁷ ,

in which

R ⁶ and R ⁷ Ci to Cι ₀ alkyl, C ₆ to Cι ₅ aryl, alkylaryl,

Arylalkyl, fluoroalkyl or fluoroaryl each having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical,

R ¹ to R ^{5 are} hydrogen, C ~ to Cio-alkyl, 5- to 7-membered cycloalkyl, which in turn can carry a Ci- to Cio-alkyl as a substituent, C_- to cis-aryl or arylalkyl, optionally also two adj - Beard residues together can represent 4 to 15 carbon atoms, saturated or unsaturated cyclic groups, or Si (R ⁸ ) with

R ⁸ Ci- to Cio-alkyl, C ₃ - to Cι ₀ cycloalkyl or C _ - to cis-aryl,

Z stands for X or

being the leftovers

R ⁹ to R ^{13 are} hydrogen, C ~ to Cio-alkyl, 5- to 7-membered

Cycloalkyl, which in turn can carry a Ci- to Cio-alkyl as a substituent, ζ- to cis-aryl or Arylalkyl mean and where optionally two adjacent radicals together for 4 to 15 C-

Atomic, saturated or unsaturated cyclic groups can be, or Si (R ¹ ) ₃ with

R ¹⁴ Ci to Cio alkyl, C ₆ - to -C ₅ aryl or C ₃ - to

Cio-cycloalkyl,

or wherein the radicals R ⁴ and Z together form a grouping -R ¹⁵ -A- in which

_R 16 _R 16 _R 16 _R 16

Rl5 M ² . M ² - M ² M ² C (R ¹⁸ ) ₂ -

R1 ⁷ Rl7 Rl ^' R ^l7

R ¹⁶ Rl6 _R 16 _R 16

0 M ²

R ¹⁷ R ¹⁷ _R l ⁷ Rl

= BR ¹⁶ , = AIR ¹⁶ , -Ge-, -Sn-, -O-, -S-, = SO, = S0, = NR ¹⁶ , = CO, = PR ¹⁶ or = P (0) R ¹⁶ ,

in which

R ¹⁶ , R ¹⁷ and R ^{18 are the} same or different and a hydrogen atom, a halogen atom, a Cι-Cιo-alkyl group, a Ci-Cio-fluoroalkyl group, a C ₆ -Cιo-fluoroaryl group, a C _ß -Cio -Aryl group, a C 1 -C ₈ -alkoxy group, a C ₈ -C ₄ alkenyl group, a C ₇ -C ₄ o-aryl-alkyl group, a C ₈ -C ₄ o-arylalkenyl group or a C ₇ -C ₄ o-alkylaryl group mean or wherein two adjacent radicals each form a ring with the atoms connecting them, and

M ^{2 is} silicon, germanium or tin,

^ NR ¹⁹ ^ PRl °

AO, S or mean with _R 19 C 1 ~ to Cio-alkyl, C ₆ - to cis-aryl, C - to Cio-cycloalkyl, alkylaryl or Si (R ²⁰ ) ₃ ,

R ^{20 is} hydrogen, C 1 to C ₀ alkyl, C ₆ to C ₅ aryl, which in turn can be substituted with C 1 to C alkyl groups or C ₃ to Cio-cycloalkyl

or where the radicals R ⁴ and R ¹² together form a group -R ¹⁵ -,

and optionally polymerized a Lewis acid activator compound.

Of the metallocene complexes of the general formula II are

MX ₃

prefers .

Those transition metal complexes which contain two aromatic ring systems bridged to one another as ligands are particularly preferred, that is to say particularly the transition metal complexes of the general formulas IIc and Ild.

The radicals X can be the same or different, they are preferably the same.

Of the compounds of the formula Ila, those are particularly preferred in which

M titanium, zirconium or hafnium,

X is chlorine, C 1 -C ₄ -alkyl or phenyl and

R ² to R ^{6 are} hydrogen or -C ~ to C ₄ alkyl.

Of the compounds of the formula IIb, preference is given to those in which

M stands for titanium, zirconium or hafnium,

X represents chlorine, C 1 -C ₄ -alkyl, phenyl or benzyl,

R ² to R ⁶ hydrogen f, Cχ ~ to C ₄ alkyl or Si (R ⁹ ) ₃ ,

R ⁱ ° to R ^{14 are} hydrogen, Ci to C ₄ alkyl or Si (R ¹⁵ ) ₃ .

The compounds of the formula IIb in which the cyclopentadienyl radicals are identical are particularly suitable.

Examples of particularly suitable compounds include bis (cyclopentadienyl) zirconium dichloride, bis (pentamethylcyclopentadienyl) zirconium dichloride. Bis (methylcyclopentadienyl) zirconium dichloride,

Bis (ethylcyclopentadienyl) zirconium dichloride,

Bis (n-butylcyclopentadienyl) zirconium dichloride and

Bis (trimethylsilylcyclopentadienyl) zirconium dichloride and the corresponding dimethyl zirconium compounds.

Of the compounds of the formula IIc, those in which

R ² and R ^{10 are the} same and represent hydrogen or

Cι ~ to Cιo ~ are alkyl groups,

R ⁶ and R ^{14 are the} same and for hydrogen, a methyl,

Ethyl, iso-propyl or tert. -Butyl group stand

R ³ , R ⁴ , R ¹¹ and R ^{12 have} the meaning

R ⁴ and R ¹² are C 1 -C ₄ -alkyl R ³ and R ^{11 are} hydrogen or two adjacent radicals R ³ and R ⁴ and R ¹¹ and R ¹² together represent cyclic groups having 4 to 12 C atoms,

R ¹⁷ _R 17 _R 17 III

R ^{16 stands} for M ² or _r r,

M for titanium, zirconium or hafnium and

X represents chlorine, C 1 -C ₄ -alkyl, phenyl or benzyl.

Examples of particularly suitable complex compounds include Dimethylsilanediylbis (cyclopentadienyl) zirconium dichloride, dirnethylsilanediylbis (indenyl) zirconium dichloride, dimethylsilanediylbis (tetrahydroindenyl) zirconium dichloride, ethylene bis (cyclopentadienyl) zirconiumdichloridyldichloridichlorid (ethylene) bis (zirconium) dichloride (ethylene

Tetramethylethylene-9-fluorenylcyclopentadienylzirconium dichloride, dimethylsilanediylbis (-3-tert-butyl-5-methylcyclopentadienyl) zirconium dichloride,

Dimethylsilanediylbis (-3-tert-butyl-5-ethylcyclopentadienyl) zirconium dichloride, Dimethylsilanediylbis (-2-methylindenyl) zirconium dichloride,

Dimethylsilanediylbis (-2-isopropylindenyl) zirconium dichloride,

Dimethylsilanediylbis (-2-tert. Butylindenyl) zirconium dichloride,

Diethylsilanediylbis (-2-methylindenyl) zirconium dibromide, dimethylsilanediylbis (-3-methyl-5-methylcyclopentadienyl) zirconium dichloride,

Dimethylsilanediylbis (-3-ethyl-5-isopropylcyclopentadienyl) zirconium dichloride,

Dimethylsilanediylbis (2-methylindenyl) zirconium dichloride, dimethylsilanediylbis (2-methylbenzindenyl) zirconium dichloride dimethylsilanediylbis (2 -ethylbenzindenyl) zirconium dichloride, methylphenylsilanediylbis (2 -ethylbenzindenyl) zirconium dichloride, methylphenylsilanediylbis (2 -methylbenzindenyl) zirconium dichloride, diphenylsilanediylbis (2 -methylbenzindenyl) zirconium dichloride , Diphenylsilanediylbis (2-ethylbenzindenyl) zirconium dichloride, and Dimethylsilandiylbis (-2-methylindenyl) hafnium dichloride and the corresponding Dimethylzirkoniumverbindungen.

In the case of the compounds of the general formula Ild, those in which

M for titanium or zirconium,

X represents chlorine, C 1 -C 4 -alkyl, phenyl or benzyl.

R ¹⁷ R ⁱ R ⁱ⁷

R ^{16 represents} M ² or _cc ,

I I I

R ¹⁸ _R 18 18

for o- R20

and

R ² to R ⁴ and R ^{6 are} hydrogen, C ~ to Cio-alkyl,

C ₃ - to Cio-cycloalkyl, C ₆ - to -C ₅ aryl or Si (R ⁹ ) ₃ , or where two adjacent radicals stand for cyclic groups having 4 to 12 C atoms. Such complex compounds can be synthesized by methods known per se, the reaction of the appropriately substituted cyclic hydrocarbon anions with halides of titanium, zirconium, hafnium, vanadium, niobium or tantalum being preferred.

Examples of corresponding manufacturing processes include in the Journal of Organometallic Chemistry, 369 (1989), 359-370.

Mixtures of different metallocene complexes can also be used.

If metal complexes of the general formula (II) are used as transition metal catalysts, a compound which forms metallocenium ions is also regularly used as an activator.

Suitable compounds which form metallocenium ions are strong, neutral Lewis acids, ionic compounds with Lewis acid cations and ionic compounds with Bronsted acids as the cation.

Compounds of the general formula lilac are strong, neutral Lewis acids

M ³ χ ^! χ ² x ³ purple preferred in the

M ^{3 is} an element of III. Main group of the periodic system means, in particular B, Al or Ga, preferably B,

X ^X , X ² and X ³ for hydrogen, Ci- to Cio-alkyl, C ₆ - bis

Cis-aryl, alkylaryl, arylalkyl, haloalkyl or haloaryl, each with 1 to 10 carbon atoms in the

Alkyl radical and 6 to 20 carbon atoms in the aryl radical or fluorine, chlorine, bromine or iodine are, in particular for haloaryls, preferably for pentafluorophenyl.

Particularly preferred are compounds of the general formula purple, in which X ¹ , X ² and X ^{3 are the} same, preferably tris (pentafluorophenyl) borane.

Ionic compounds with Lewis acid cations are compounds of the general formula IIIb [(Y ^a +) QlQ ₂ . , , Q _z ] d + _{II Ib}

suitable in which

Y is an element of I. to VI. Main group or the

I. to VIII. Subgroup of the periodic table means

Q to Q _z for single negatively charged radicals such as Ci- to C ₂₈ -alkyl, C ₆ - to Cι- ₅ aryl, alkylaryl, arylalkyl,

Haloalkyl, haloaryl each having 6 to 20 C atoms in the aryl and 1 to 28 C atoms in the alkyl radical, Ci to Cio-cycloalkyl, which can be substituted by Ci- to Cio-alkyl groups, halogen, Ci to C ₂₈ -Alkoxy, C ₆ - to cis-aryloxy,

Silyl or mercaptyl groups

a stands for integers from 1 to 6

z for integers from 0 to 5

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

Carbonium cations, oxonium cations and sulfonium cations as well as cationic transition metal complexes are particularly suitable. The triphenylmethyl cation, the silver cation and the 1, 1 '-dimethylferrocenyl cation should be mentioned in particular. They preferably have non-coordinating counterions, in particular boron compounds, as they are also mentioned in WO 91/09882, preferably tetrakis (pentafluorophenyl) borate.

Ionic compounds with Bronsted acids as cations and preferably also non-coordinating counterions are mentioned in WO 91/09882; the preferred cation is N, N-dimethylanilinium.

Open-chain or cyclic alumoxane compounds of the general formula IIIc or IIld are particularly suitable as compounds which form metallocenium ions R ^l

Al-AH fO R ^l IIIc i

R ^l

R ^l

where a -C ~ to C ₄ alkyl group, preferably a methyl or ethyl group and k is an integer from 5 to 30, preferably 10 to 25.

These oligomeric alumoxane compounds are usually prepared by reacting a solution of trialkylaluminum with water and include in EP-A 284 708 and US A 4,794,096.

As a rule, the oligomeric alumoxane compounds obtained in this way are present as mixtures of both linear and cyclic chain molecules of different lengths, so that m is to be regarded as the mean. The alumoxane compounds can also be present in a mixture with other metal alkyls, preferably with aluminum alkyls.

Aryloxyalumoxanes, as described in US Pat. No. 5,391,793, aminoaluminoxanes, as described in US Pat. No. 5,371,260, aminoaluminoxane anhydrochlorides, as described in EP-A 633,264, and siloxyaluminoxanes, can also be used as compounds which form metallocenium ions described in EP-A 621 279, or mixtures thereof are used.

Particularly preferred metallocene complexes are ethylene bis (indenyl) hafnium dichloride and dimethylsilanediylbis (2-methyl-4,5-benzindenyl) zirconium dichloride. Very particularly preferred metallocene catalysts are ethylene bis (indenyl) haf - nium dichloride / methylaluminoxane and dimethylsilanediylbis (2-methyl-4,5-benzindenyl) zirconium dichloride / methylaluminoxane catalysts.

The process according to the invention for the production of polyolefin nanocomposites by means of metallocene catalysts (II) is generally carried out at temperatures in the range from -50 to 300 ° C., preferably in the range from 0 to 150 ° C. and in particular in the range from 0 to 100 ° C and at pressures in the range from 0.01 to 3000 bar, preferably 0.1 to 100 bar and in particular from 0.1 to 50 bar. Further details on the implementation of such polymerizations in high-pressure reactors are described, for example, in "Ulimann's Encyclopedia of Industrial Chemistry", Verlag Chemie, Weinheim, Volume 19, 1980, pages 169-195.

The polymerization time is usually in the range from 1 min to 12 h. Satisfactory results can already be achieved with response times of less than 20 minutes.

In a further preferred embodiment, the monomers are in the presence of the sheet silicates described and a transition metal complex of the general formula (VII)

in which the substituents have the following meaning:

M *: Fe or Co, preferably Fe,

R ^e , R ^f independently of one another hydrogen, Ci to Cio alkyl, preferably Ci to C ₄ alkyl, in particular methyl, C ₆ to

Cio-aryl, especially phenyl, or alkylaryl with 1 to 6 carbon atoms in alkyl and 6 to 10 carbon atoms in the aryl part, for example benzyl,

R9, R ^h , R ⁱ independently of one another are hydrogen, straight-chain or branched C ₁ -C 10 -alkyl, preferably C ₁ -C ₆ -alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl , t-butyl, partially or perhalogenated Ci- to Cio-alkyl, preferably Ci to _C6 alkyl, such as trifluoro- or trichloromethyl or 2, 2, 2-trifluoroethyl, substituted or unsubstituted Ci to Cio-cycloalkyl, preferably C ₃ - to C_ -cycloalkyl, such as cyclopropyl, cyclopentyl, Cyclohexyl, 1-methylcyclohexyl or 4-t-butylcyclohexyl, Cß- to Cι-aryl, preferably C ₆ - to Cio-aryl, such as phenyl or naphthyl, in particular phenyl, trioganosilyl, for example trimethyl, triethyl, Ti-t-butyl -, Tri - phenyl- or t-butyl-di-phenylsilyl, amino, for example NH2, dimethylamino, di-i-propylamino, di-n-butylamino, diphenylamino or dibenzylamino, Ci to Cio-alkoxyoxy preferably Ci to C ₆ alkoxy, for example methoxy, ethoxy or t-butoxy, or halogen such as fluoride, chloride or bromide, and

Shark independently of chloride, bromide or iodide, especially chloride.

In general, the valences of pyridyl or of the phenyl rings not explicitly mentioned in the general formula (VII) are occupied by hydrogen. Of course, these valences can also be replaced by other residues, e.g. Alkyl such as methyl, aryl such as phenyl or halogen such as chlorine may be saturated.

A compound of the general formula (VII) in which M * is iron, R ^e , R ^{f is} hydrogen or methyl, R ^* 3, R ^h , R ^{i is} hydrogen, methyl or i-propyl and shark is particularly preferably chloride.

Further explanations on the aforementioned metal complex include in Britovsek et al. , J. Chem. Soc, Chem. Commun. 1998, pp. 849-850.

Preference is given to activating compounds (VII)

Alumoxanes, i.e. reagents that fall under the formulas IIIc and Illd already described, e.g. MAO, brought up.

The polymerization in the presence of compounds (VII) can be carried out in aromatic hydrocarbons such as benzene, toluene or xylene or in aliphatic hydrocarbons such as i-butane or i-do-decane. The reaction pressures are generally in the range from 0.1 to 100 bar, preferably in the range from 1 to 40 bar. The polymerization can also be carried out at room temperature at temperatures in the range from 0 to 100C.

The polymerization processes according to the invention can be carried out in solution, in suspension, in the liquid monomers or in the gas phase. The polymerization is preferably carried out in solution or in the liquid monomers. Suitable solvents for solution polymerization are aliphatic or aromatic, organic solvents, which can also be halogenated. Examples include toluene, ethylbenzene, chlorobenzene, dichloromethane, i-butane and heptane.

The polymerization process according to the invention can be carried out continuously or batchwise. Suitable reactors include continuously operated stirred kettles, it also being possible, if appropriate, to use a number of several stirred kettles connected in series (reactor cascade), and also a tubular reactor or loop reactor.

The polymerization can be terminated by adding proton-active compounds such as mineral or organic acids, alcohols or water and mixtures of the compounds mentioned. As organic acids e.g. Acetic acid or benzoic acid are suitable, as alcohols include Methanol, ethanol or i-propanol into consideration.

Suitably, the metallocene compound (II) is present in the reaction vessel in an inert aromatic solvent or in an aliphatic hydrocarbon. As aromatic solvents there are e.g. moderately polar liquids such as toluene or xylene. Among the aliphatic hydrocarbons, hexane, heptane, octane, nonane, decane, dodecane and isododecane or mixtures thereof can be used.

The transition metal compounds (Ia) or (Ib) or the metal ocene complexes (II) can be introduced or added to the polymerization mixture after the monomers have been added. The same applies to the compounds forming the metallocenium ions

Activators too. In a further embodiment, the aforementioned components can be added to the reaction mixture in a final step under the previously set polymerization conditions.

The layered silicate dispersion is usually placed in the reaction vessel. In addition, this dispersion can also be added to the reaction mixture after the monomers have been added or continuously during the course of the reaction.

It can be readily up to 60 wt -.% Or more, preferably up to 40 wt -.%, Of layered silicate in the polyolefin atrix a ^¬ build. However, fundamental improvements in properties compared to unreinforced polyolefins usually go hand in hand with very low layered silicate contents, for example with contents in the range from 0.5 to 5% by weight. With the process according to the invention, nanocomposite polymers can be produced, polymerizing in the presence of the layered silicates, under homogeneous catalytic conditions. In addition, the process according to the invention is distinguished in that, regardless of the batch size of the polymerization, there is no or only a negligible amount of reactor fouling.

In the polyolefin nanocomposites obtained by the process according to the invention, the layered silicates are in the form of nano-structures. Compared to conventional polyolefins, these polyolefin nanocomposites are characterized by greater rigidity, higher hardness, improved gas and liquid barrier properties, by a shear-dependent viscosity, better flame retardant properties and, in particular compared to glass fiber-reinforced products, by better surface properties and an improved surface gloss.

The polyolefin nanocomposites obtained can be e.g. Process into fibers, moldings and foils using injection molding, extrusion, film blowing or blow molding.

The polyolefin nanocomposites obtained by the process according to the invention are used in the production of fibers, films and moldings.

The present invention is illustrated by the following examples.

Examples:

Abbreviations:

DMN: [bis-N, N '- (2,6-diisopropylphenyl) -1,4-diaza-2,3-dimethyl-1,3-butadiene] nickel dibromide

DMPN: [bis-N, N '- (2,6-diisopropylphenyl) -1,4 -diaza-2,3,3-dimethyl-1,3-butadiene] palladium- (aceto-nitrile) (methyl) - ( tetra (3,5-bis - (trifluoromethyl) phenylborate)

MBI: rac-dimethylsilylenebis (2-methylbenz [e] indenyl) zirconium dichloride

MAO: methylalumoxane solution. in toluene (approx. 10% by weight) DSC (Differential Scanning Calorimetry) measurements to determine melting temperatures (T _m ) and glass transition temperatures (T _g ) were carried out on the Perkin Eimers Series 7. The heating or cooling rate was 10 K / min.

GPC measurements (gel permeation chromatography) of the polymers which are not soluble in toluene at room temperature were carried out on approx. 0.04% by weight solutions in 1, 2, 4 -trichlorobenzene at a flow of 1.0 mol / min using Shodex Separation columns (guard column Shodex GPC AT-800P, linear column Shodex GPC AT-80 M / S 3x and high molecular column Shodex GPC AT-807 S lx). The measurement was carried out against the polyethene standard. An infrared detector (λ = 3.5 μm) was used for the detection.

The measurement of the ethene mass flow during the polymerization was carried out using the Brooks mass flow controller 5850E (Brooks Instrument B.V., Holland).

Nuclear Magnetic Resonance Spectroscopy (NMR)

¹ H-NMR spectra and ⁱ³ C -NMR spectra were measured on a Bruker ARX 300. In the case of the homopolymers and copolymers catalyzed by nickel or zirconium, 50 mg of polymer were dissolved in 0.6 to 0.8 ml of CD ₂ C1 ₄ under protective gas. The spectra were recorded at 130 ° C. The palladium-bisimine / borate-catalyzed homopolyethenes were each weighed into CDC1 ₃ with 50 mg. The spectra were recorded at 25 ° C.

The commercial products Optigel ^® and Tixogel ^® VZ from Süd-Chemie, Munich, were used as layered silicates. Optigel is an untreated, synthetic layered silicate of bentonite type. Tixogel ^® VZ is an organophilic sheet silicate of the bentonite type, which has been swollen with dimethylstearylbenzylammonium chloride. The sheet silicates were used without further purification steps directly for the preparation of the dispersion or for the polymerization.

General polymerization conditions

The polymerizations were carried out in a reactor system from Buch! (Büchi AG, Uster, CH). Glass reactors with a capacity of 1.0 1 and 1.6 1 were used, which are permitted up to 6 bar overpressure.

The reactor was rendered inert before each polymerization. Pressure and temperature in the reactor were recorded using electronic sensors. The temperature was automatically adjusted using a Julabo thermostat set table and kept constant. The ethene pressure in the reactor was kept constant using a pressure gauge. A mass flow meter determined the amount of ethene consumed and recorded this as a function of time. The polymerization was started using a pressure burette.

I. Ethene polymerization in the presence of layered silicates

Layered silicate and solvent were added to a 1.0 l glass reactor under argon and the mixture was heated to 40 ° C. with stirring (1000 rpm). The argon atmosphere was removed by repeated flooding with ethene. The ethene pressure was set at 6 bar. The catalyst and optionally the cocatalyst / activator were added to the reaction mixture, dissolved in 10 ml of toluene. The temperature and pressure were kept constant throughout the polymerization. The reaction was stopped by adding isopropanol (20 ml), the reaction vessel was opened and the polymer product by adding a mixture of methanol (2 1) and 1/3 conc. Hydrochloric acid (15 ml) precipitated. The precipitation mixture was stirred for 2 hours and the polymer product was collected by filtration. After drying and removal of the last solvent residues in a high vacuum at 60 ° C. for 24 h, the polyethylene nanocomposite was obtained. Further information on the test parameters and the product properties can be found in Table 1 below.

II. Ethene / oct-1-ene copolymerization with MBI as catalyst

The procedure was as described under I., with the difference that 12.6 ml (Examples 18 and 19) and 50.6 ml (Examples 16, 17 and 20 to 24) of 1-octene were added before the polymerization vessel was flooded with ethene. The ethene pressure was set at 4 bar.

Further information on test parameters and product properties can be found in Table 2.

III. Ethene polymerization in the presence of delaminated layered silicates

The procedure was as described under I., with the difference that the 1.6 l glass reactor was operated with stirring at 600 rpm. SOMASIF ¹⁸ 'ME 100, which has been treated with different delaminating agents, can be used as layered silicate. For this purpose, 1 kg each of SOMASIF® ME 100 was dispersed in 20 1 warm water (25 1 stirred reactor). 1.2 mol of an amine and 120 ml of conc. Given hydrochloric acid. The mixture was stirred at 70 ° C. for 1 h, finally filtered, washed with 80 liters of warm water, dried and finally ground. The test parameters and product properties are shown in Table 3.

a) comparison test; layered silicate was not added to the polymerization mixture.

b) The layered silicate was placed in the form of a dispersion in toluene (10 ml) in the polymerization vessel. This dispersion was previously prepared separately using an Ultra-Turrax T25 from Jahnke and Kunkel (10,000 rpm over a period of 30 minutes).

υ XI

Table 3:

each as chloride

Claims

claims

1. A process for the preparation of polyolefin nanocomposites, characterized in that C ₂ - to C o-alk-l-enes or vinylaromatic compounds are polymerized in the presence of a dispersion of one or more phyllosilicates in a transition metal-catalyzed manner.

2 Process for the preparation of polyolefin nanocomposites according to claim 1, characterized in that C ₂ - to C ₂ o-alk-l-enes or vinylaromatic compounds in the presence of a dispersion of one or more phyllosilicates in a non-polar aliphatic or aromatic dispersant and a transition metal compound general formula (la) or (Ib)

(Ia) (Ib)

in which the substituents and indices have the following meaning:

R ⁱ 'to R ⁴ ' hydrogen, Cι ~ to Cio-alkyl, partially or per-halogenated C ~ to Cio-alkyl, C ₃ - to Cio-cycloalkyl, C ₆ - to Cι-aryl, with functional groups the basis of the elements from groups IVA, VA, VIA and VIIA of the periodic table of the elements, partially or per-substituted C ₆ to C aryl, C ₄ to C ₃ heteroaryl, alkylaryl with 1 to 10 carbon atoms in the alkyl and 6 to 14 carbon atoms in the aryl radical or Si (R ⁶ '), where R ¹ ' and R ⁴ 'are not hydrogen, or R ⁱ 'and R ² ' together with C ^a and N ^a or R ³ 'and R ⁴ ' together with C ^b and N ^{b form} a five-, six- or seven-membered aromatic or aliphatic, substituted or unsubstituted heterocycle, or

R ² 'and R ³ ' together with C ^a and C ^{b form} a five-, six- or seven-membered aliphatic or aromatic, substituted or unsubstituted carbo- or heterocycle,

R ⁵ 'is hydrogen, Ci- to Cio-alkyl, C ₃ - to Cio-cycloalkyl, C _ß - to -CC aryl, alkylaryl with 1 to 10 carbon atoms in the alkyl and 6 to 14 carbon atoms in the aryl radical or Si (R ⁶ ') ₃ ,

R ⁶ 'Ci to Cio-alkyl, C ₃ - to Cio-cycloalkyl, C ₆ - bis

-C aryl, alkylaryl with 1 to 10 carbon atoms in the alkyl and 6 to 14 carbon atoms in the aryl radical,

m 0 or 1,

M 'is an element from Group VIIIB of the Periodic Table of the Elements,

Q 'acetonitrile, benzonitrile, a linear alkyl ester, a linear or cyclic aliphatic ether, dimethyl sulfoxide, dimethylformamide, hexamethylphosphoric triamide or halides,

T 'chloride, bromide, iodide or a Cι ~ to C o ~ alkyl, which has no hydrogen atoms in the ß-position to the metal center M', and optionally has a Cι ~ to C -alkyl ester end group or a nitrile end group, or Q 'and T 'together form a C ₃ alkylene chain with a linea ^¬ ren Cι ~ to C alkyl ester or nitrile end group,

A 'a non- or poorly coordinating anion and

n 0, 1, 2 or 3, or a metallocene complex of the general formula (II)

in which the substituents have the following meaning:

M titanium, zirconium, hafnium, vanadium, niobium or tantalum

X is hydrogen, C ~ to Cio-alkyl, C ₆ - to

Cι ₅ -aryl, alkylaryl having from 1 to 10 carbon atoms in the alkyl radical and 6 to 20 C atoms in the aryl radical, -OR ⁶ or -NR ⁶ R ^7,

in which

R ⁶ and R ^{7 are} C 1 to C 10 alkyl, C ₆ to C ₅ aryl, alkylaryl, arylalkyl, fluoroalkyl or fluoroaryl each having 1 to 10 C atoms in the alkyl radical and 6 to 20 C atoms in the aryl radical,

R ⁱ to R ^{5 are} hydrogen, Cι ~ to Cι ₀ alkyl, 5- to

7-membered cycloalkyl, which in turn can carry a C ₁ -C 1 -alkyl group as a substituent, C ₆ - to cis-aryl or arylalkyl, where two adjacent radicals together represent saturated or unsaturated cyclic groups having 4 to 15 C atoms can, or Si (R ⁸ ) ₃ with

R ⁸ Ci- to Cio-alkyl, C ₃ - to -CC ₀ cycloalkyl

being the leftovers R ⁹ to R ⁱ³ Wasserstof f, C _x - ₀ to Cι alkyl, 5- to

7-membered cycloalkyl, which in turn can carry a C ₁ to C 10 alkyl as a substituent, are C ₆ - to Cis-aryl or arylalkyl, and where appropriate also two adjacent radicals together for 4 to 15 C atoms, saturated or unsaturated cyclic Groups can stand, or Si (R ⁱ⁴ ) ₃ with

R ¹⁴ Ci to Cio alkyl, C ₆ to C ₅ aryl or C ₃ to Cio cycloalkyl,

or wherein the radicals R ⁴ and Z together form a group -R ⁱ⁵ -A- in which

_R 16 _R 16 _R 16 _R 16

M ² . M ² - M ² M ² C (Rl 8) ₂ -

Rl7 _R 17 _R 17 _R 17

R ¹⁶ Rl6 _R 16 _R 16

Rl7 _R 17 _R i7 _R 17

= BR ^{l * 5} , = A1R ¹⁶ , -Ge-, -Sn-, -O-, -S-, = SO, = S0 ₂ , NR ¹⁶ , = CO, = PR ^iß or = P (0) R ⁱ⁶ is

in which

R ⁱ⁶ , R ^{l "7} and R ^{18 are the} same or different and one

Hydrogen atom, a halogen atom, a Cι-Cιo-alkyl group, a Cι-Cιo ~ fluoro-alkyl group, a Cς-Cio-fluoroaryl group, a C ₆ -Cιo aryl group, one

Cι-Cιo-alkoxy group, a C -Cιo ~ alkenyl group, a C ₇ -C o-arylalkyl group, a C ₈ -C ₄ o-arylalkenyl group or a C ₇ -C o-alkylaryl group, or two adjacent radicals each with the atoms connecting them form a ring, and

M ^{2 is} silicon, germanium or tin,

^ NR ⁱ⁹ ^ .PR °

A 0, S, or mean with

R ⁱ⁹ Ci to Cio-alkyl, C ₆ to Cis-aryl, C ₃ to Cio-cycloalkyl, alkylaryl or Si (R ²⁰ ) ₃ ,

R ^{20 is} hydrogen, Cι ~ to Cio-alkyl, Ce ~ bis

Cis-aryl, which in turn can be substituted with -C ~ to C ₄ alkyl groups or C ₃ - to Cio-cycloalkyl

or where the radicals R ⁴ and R ⁱ² together form a group -R ⁵ -,

and optionally polymerized a Lewis acid activator compound.

Process according to Claims 1 or 2, characterized in that the transition metal compound of the general formula (I)

[Bis-N, N '- (2, 6-diisopropylphenyl) -1, 4-diaza-2, 3-dimethyl-1,3-butadiene] palladium-acetonitrile-methyl- (tetra (3, 5-bis- ( trifluoromethyl) phenyl) borate),

[Bis-N, N '- (2, 6-diisopropylphenyl) -1, 4-diaza-2, 3-dimethyl-1,3-butadiene] palladium-diethylether-methyl- (tetra (3, 5-bis- ( trifluoromethyl) phenyl) borate),

[Bis-N, N '- (2, 6-diisopropylphenyl) -1, 4-diaza-2, 3-dimethyl-1,3-butadiene] -palladium-h ⁱ -O-methylcarboxypropyl- (tetra (3, 5 bis (trifluoromethyl) phenyl) borate),

[Bis-N, N '- (2, 6-diisopropylphenyl) -1, 4-diaza-l,

3-butadiene] pal- ladium-h ⁱ -O-methylcarboxypropyl- (tetra- (3,5-bis- (trifluoromethyl) phenyl) borate) or [bis-N, N '- (1-naphthyl) -1,

4-diaza-2,3-dimethyl-1,3-butadiene] palladium-h ⁱ -0-methylcarboxypropyl- (tetra (3,5-bis- (trifluoromethyl) phenyl) borate)

used.

. Process according to Claims 1 or 2, characterized in that the metallocene complex (II)

Bis (cyclopentadienyl) zirconium dichloride, bis (pentamethylcyclopentadienyl) zirconium dichloride, bis (methylcyclopentadienyl) zirconium dichloride, bis (ethylcyclopentadienyl) zirconium dichloride, bis (n-butylcyclopentadienyl) zirconium dichloride, bis (trimethylsilylcyclopentadienyl) zirconium dichloride, dimethylsilanediylbis (cyclopentadienyl) zirconium dichloride, Dimethylsilanediylbis (indenyl) zirconium dichloride,

Dimethylsilanediylbis (tetrahydroindenyl) zirconium dichloride, ethylene bis (cyclopentadienyl) zirconium dichloride, ethylene bis (indenyl) zirconium dichloride, ethylene bis (tetrahydroindenyl) zirconium dichloride, tetramethylethylene-9-fluorenylchloridium,

Dimethylsilanediylbis (-3-tert. Butyl-5-methylcyclopentadienyl) zirconium dichloride, dimethylsilanediylbis (-3-tert. Butyl-5-ethylcyclopentadienyl) zirconium dichloride,

Dimethylsilanediylbis (-2-methylindenyl) zirconium dichloride, dimethylsilanediylbis (-2-isopropylindenyl) zirconium dichloride, dimethylsilanediylbis (-2-tert -methylcyclopentadienyl) zirconium dichloride,

Dimethylsilanediylbis (-3-ethyl-5-isopropylcyclopentadienyl) zirconium dichloride, dimethylsilanediylbis (-2-methylindenyl) zirconium dichloride,

Dimethylsilanediylbis (-2-methylbenzindenyl) zirconium dichloride dimethylsilanediylbis (2-ethylbenzindenyl) zirconium dichloride, methylphenylsilanediylbis (2-ethylbenzindenyl) zirconium dichloride, methylphenylsilanediylbis (2-methylbenziridium) zirconium dichloride

Diphenylsilanediylbis (2-methylbenzindenyl) zirconium dichloride, diphenylsilanediylbis (2-ethylbenzindenyl) zirconium dichloride or dimethylsilanediylbis (-2-methylindenyl) hafnium dichloride.

5. Process according to claims 1 to 4, characterized in that sodium silicate, makatite, magdiite, kenyaite, kanemite, revolite, grumantite, talc, mica, kaolinite, bentonite, montmorillonite, smectite, illite, sepiolite, palygorskite are used as layer silicates , Muscovite, allevardite, amesite, hectorite, fluorohectorite, saponite, beidellite, nontronite, stevensite, vermicu- lit, fluorvermiculite, halloysite or fluorine-containing synthetic mica types or a mixture of the layered silicates mentioned.

6. Process according to claims 1 to 5, characterized in that dichloromethane, toluene, benzene or xylene or a mixture of the liquids mentioned is used as the dispersant.

7. Process according to claims 1 to 6, characterized in that as C ₂ - to C ₂ o-alk-l-ene ethene or propene or ethene and propene, but-l-ene, pent-1-ene, hex -l-ene, hept-1-ene or oct-l-ene and styrene or α-methylstyrene are used as vinyl aromatic compounds.

Polyolefin nanocomposites obtainable according to claims 1 to 7.

9. Use of the polyolefin nanocomposites according to claim 8 for the production of films, moldings and fibers.