Process for producing multi-phase homo- or copolymers of C2-C10-alcenes in one reaction zone.

The present invention relates to a process for the preparation of multiphase homopolymers or copolymers of C₂-C₁₀-alk-1-enes.

Furthermore, the present invention relates to the use of the homopolymers or copolymers obtained by the process according to the invention for the production of films, fibers or moldings.

Multi-phase homopolymers or copolymers of C₂-C₁₀-alk-1-enes are usually prepared by a multi-stage polymerization process, the polymer obtained in a first reaction zone first being transferred to a second reaction zone, where this is a mixture of one or more C₂-C₁₀ -Alk-1-enen is polymerized. In this way, a mixture of two different polymers is formed in the second reaction zone. Under certain circumstances, the mixture obtained from the second polymerization zone can be introduced into one or more further reaction zones, where further C₂-C₁₀-alk-1-enes are polymerized in (DE-A 40 04 087, DE-A 40 19 453).

The previously known processes are relatively complex in terms of process engineering, since on the one hand the reactor guidance in the individual reaction zones has to be coordinated with one another and on the other hand the transfer of polymers from one reaction zone to the other is associated with some difficulties in terms of control technology. In addition, such multi-stage processes always require a very complex apparatus, which is associated with considerable investment costs.

The object of the present invention was therefore to remedy the disadvantages described and to develop a less technically complex process for the production of multiphase homopolymers or copolymers of C₂-C₁₀-alk-1-enes.

Accordingly, a process for the preparation of multiphase homopolymers or copolymers of C₂-C₁₀-alk-1-enes has been found, which is characterized in that polymerization is carried out in the presence of two different catalyst systems, one of the catalyst systems being active

Constituents of a metallocene complex of the general formula (I) or (II)<chemistry id="chem0001" num="0001"><img file="EP0643084A2_D0001.tif" /></chemistry> wherein<dl id="dl0001"><dt>M¹</dt><dd>is a metal from group IVb, Vb or VIb of the periodic table,</dd><dt>R1 and R2</dt><dd>are identical or different and are a hydrogen atom, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a C₆-C₁₀ aryl group, a C₆-C₁₀ aryloxy group, a C₂-C₁₀ alkenyl group, a C₇-C₄₀ arylalkyl group, is a C₇-C₄₀-alkylaryl group, a C₈-C₄₀-arylalkenyl group or a halogen atom,</dd><dt>R³ and R⁴</dt><dd>are identical or different and represent a hydrogen atom, a halogen atom, a C₁-C₁₀ alkyl group which may be halogenated, a C₆-C₁₀ aryl group, an -NR₂¹⁰, -SR¹⁰, -OSiR₃¹⁰ -SiR₃¹⁰ or -PR₂¹⁰ radical, in which R¹⁰ is a halogen atom, a C₁-C₁₀ alkyl group or a C₆-C₁₀ aryl group.</dd><dt>R⁵ and R⁶</dt><dd>are the same or different and have the meaning given for R³ and R⁴, with the proviso that R⁵ and R⁶ are not hydrogen.</dd><dt>R⁷</dt><dd><chemistry id="chem0002" num="0002"><img file="EP0643084A2_D0002.tif" /></chemistry> = BR¹¹, = AlR¹¹, -Ge-, -Sn-, -O-, -S-, = SO, = SO₂, = NR¹¹, = CO, = PR¹¹ or = P- (O) R¹¹,</dd></dl> in which<dl id="dl0002"><dt>R¹¹, R¹² and R¹³</dt><dd>are the same or different and represent a hydrogen atom, a halogen atom, a C₁-C₁₀ alkyl group, a C₁-C₁₀ fluoroalkyl group, a C₆-C₁₀ aryl group, a C₆-C₁₀ fluoroaryl group, a C₁ C₁₀ alkoxy group, a C₂-C₁₀ alkenyl group mean a C₇-C₄₀-arylalkyl group, a C₈-₄₀-arylalkenyl group, a C₇-₄₀-alkylaryl group or R¹¹ and R¹² or R¹¹ and R¹³ each form a ring with the atoms connecting them,</dd><dt>M²</dt><dd>Is silicon, germanium or tin,</dd><dt>R⁸ and R⁹</dt><dd>are identical or different and have the meaning given for R¹¹ and</dd><dt>m and n</dt><dd>are identical or different and are zero, 1 or 2, where m plus n is zero, 1 or 2,</dd></dl> and contains an oligomeric alumina compound.

Alkyl stands for straight-chain or branched alkyl. Halogen (halogenated) means fluorine, chlorine, bromine or iodine, preferably fluorine or chlorine.

The process according to the invention is used for the production of multiphase homopolymers or copolymers of C₂-C₁₀-alk-1-enes, in particular of C₂-C₆-alk-1-enes. Particularly preferred C₂-C₆-alk-1-enes are ethylene, propylene, but-1-ene, pent-1-ene or hex-1-ene. The term multi-phase homopolymers or copolymers of C₂-C₁ Alk-alk-1-enes is to be understood in addition to three- and four-phase mixtures, in particular two-phase mixtures of homo- or copolymers of these C₂-C₁₀-alk-1-enes. Examples of particularly preferred two-phase mixtures include copolymers of ethylene or propylene with other copolymers of ethylene or propylene, minor amounts in the copolymers, ie up to 40% by weight, in particular up to 30% by weight, of further C₂-C₆alk-1-enes, for example propylene, ethylene, but-1-ene, pent-1-ene or hex-1-ene, are present can. Further preferred two-phase mixtures include two different homopolymers of propylene or other C₂-C₆-alk-1-enes, or a homopolymer of ethylene or propylene with a copolymer of ethylene or propylene with minor proportions, ie up to 40 wt .-%, in particular up to 30 wt .-% of further C₂-C₆-alk-1-ene.

Ziegler-Natta catalyst systems can be used as catalyst systems by the process according to the invention.

In addition to a titanium-containing solid component, Ziegler-Natta catalyst systems also contain a cocatalyst. An aluminum compound can be used as a cocatalyst. In addition to this aluminum compound, an electron donor compound is preferably also used as a further component of the cocatalyst. The polymerization takes place in the reactors which are usually used in the art for polymerization reactions, preferably in the gas phase.

To produce the titanium-containing solid component, the titanium compounds used are, in particular, halides or alcoholates of trivalent or tetravalent titanium, the chlorides of titanium, in particular titanium tetrachloride, being preferred. The titanium-containing solid component advantageously contains a finely divided carrier, for which silicon and aluminum oxides and aluminum silicates of the gross formula SiO₂ · aAl₂O₃, where a stands for a value from 0.001 to 2, in particular from 0.01 to 0.5, have proven successful. Other carriers include finely divided polyolefins, for example finely divided polypropylene.

Furthermore, compounds of magnesium are used in the production of the titanium-containing solid component. As such, in particular magnesium halides, magnesium alkyls and magnesium aryls, and also magnesium alkoxy and magnesium aryloxy compounds come into consideration, magnesium dichloride, magnesium dibromide and magnesium di (C₁-C₁₀-alkyl) compounds being preferably used. In addition, the titanium-containing solid component can also contain halogen, preferably chlorine or bromine.

The titanium-containing solid component also contains electron donor compounds, for example mono- or polyfunctional carboxylic acids, carboxylic acid anhydrides and carboxylic acid esters, furthermore ketones, ethers, alcohols, lactones, and organophosphorus and organosilicon compounds. Preferred electron donor compounds within the titanium-containing solid component are phthalic acid derivatives of the general formula III<chemistry id="chem0003" num="0003"><img file="EP0643084A2_D0003.tif" /></chemistry> used, where X₁ and Y₁ each represent a chlorine atom or a C₁- to C₁₀ alkoxy radical or together represent oxygen. Particularly preferred electron donor compounds are phthalic esters, where X₁ and Y₁ represent a C₁-C₈ alkoxy radical, for example a methoxy, ethoxy, propyloxy or a butoxy radical.

Other preferred electron donor compounds within the titanium-containing solid components include diesters of 3- or 4-membered, optionally substituted cycloalkyl-1,2-dicarboxylic acids, and monoesters of optionally substituted benzophenone-2-carboxylic acids.

The hydroxy compounds used in these esters are the alcohols customary in esterification reactions, including C₁ to C₁₅ alkanols, C₅ to C₇ cycloalkanols, which in turn can carry C₁ to C₁₀ alkyl groups, and also C₆ to C₁₀ phenols.

The titanium-containing solid component can be produced by methods known per se. Examples of this are described, inter alia, in EP-A 45 975, EP-A 45 977, EP-A 86 473, EP-A 171 200, GB-A 2 111 066 and US-A 4 857 613.

The resulting titanium-containing solid component is used with cocatalysts as the Ziegler-Natta catalyst system. Aluminum compounds and other electron donor compounds can be used as cocatalysts.

In addition to trialkyl aluminum, suitable aluminum compounds as cocatalyst are also those compounds in which an alkyl group is replaced by an alkoxy group or by a halogen atom, for example by chlorine or bromine. Trialkylaluminum compounds are preferably used, the alkyl groups of which each have 1 to 8 carbon atoms, for example trimethyl, triethyl or methyldiethylaluminum.

In addition to the aluminum compound, electron donor compounds such as, for example, monofunctional or polyfunctional carboxylic acids, carboxylic acid anhydrides and carboxylic acid esters, ketones, ethers, alcohols, lactones, and organophosphorus and organosilicon compounds are preferably used in addition to the aluminum compound. Preferred electron donor compounds are organosilicon compounds of the general formula IV         R¹⁴_pSi (OR¹⁵)_4-p         IV in which R¹⁴ is the same and is a C₁ to C₂₀ alkyl group, a 5- to 7-membered cycloalkyl group, which in turn can carry a C₁ to C₁₀ alkyl group, or a C₆ to C₂₀ aryl or arylalkyl group, R¹⁵ is the same or is different and is a C₁ to C₂₀ alkyl group and p represents the numbers 1, 2 or 3. Particularly preferred are compounds in which R¹⁴ is a C₁ to C₈ alkyl group or a 5- to 7-membered cycloalkyl group, and R¹⁵ is a C₁ to C₄ alkyl group and p represents the numbers 1 or 2.

Among these compounds, dimethoxydiisopropylsilane, dimethoxyisobutylisopropylsilane, dimethoxydiisobutylsilane, dimethoxydicyclopentylsilane, diethoxyisobutylisopropylsilane and dimethoxyisopropylsec.butylsilane are particularly noteworthy.

Catalyst systems are preferably used in which the atomic ratio between aluminum from the aluminum compound and titanium from the titanium-containing solid component is 10: 1 to 800: 1, in particular 20: 1 to 200: 1, and the molar ratio between the aluminum compound and the electron donor compound used as cocatalyst 1: 1 to 100: 1, in particular 2: 1 to 80: 1. The individual catalyst components can be introduced into the polymerization system individually in any order or as a mixture of two components.

In addition, in the process according to the invention, instead of the Ziegler-Natta catalyst systems, catalyst systems can be used which contain, as active constituents of the general formula (I) and (II), different metallocene complexes of metals of subgroup IV and V of the periodic table and oligomeric aluminum oxide compounds. Metallocene complexes of titanium, zirconium, hafnium, vanadium, niobium or tantalum are preferred.

Those complex compounds are preferably used in which the metal atom is connected via π bonds to unsaturated cyclic hydrocarbon radicals, for example cyclopentadienyl, fluorenyl or indenyl groups. Furthermore, the preferred complex compounds are characterized in that the metal atom is also linked to broad ligands, in particular fluorine, chlorine, bromine and iodine or a C₁ to C₁₀ alkyl, for example a methyl, ethyl, propyl or butyl group can.

Particularly suitable metallocene complexes can be characterized by the following general formula V:<chemistry id="chem0004" num="0004"><img file="EP0643084A2_D0004.tif" /></chemistry> in which the substituents have the following meaning:<dl id="dl0003"><dt>M</dt><dd>Titanium, zirconium, hafnium, vanadium, niobium or tantalum,</dd><dt>X</dt><dd>Fluorine, chlorine, bromine, iodine, hydrogen, C₁ to C₁₀ alkyl, C₆ to C₁₅ aryl or -OR²⁰,</dd></dl> in which<dl id="dl0004"><dt>R²⁰</dt><dd>C₁ to C₁₀ alkyl, C₆ to C₁₅ 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,</dd><dt>R¹⁶ to R¹⁹</dt><dd>and R²¹ to R²⁴ are hydrogen, C₁- to C₁₀-alkyl, 5- to 7-membered cycloalkyl, which in turn can carry C₁- to C₁₀-alkyls as substituents, C₆- to C₁₅-aryl or arylalkyl, optionally also two adjacent radicals together can represent cyclic saturated, partially saturated or unsaturated groups having 4 to 15 carbon atoms, or Si (R²⁵) ₃ with</dd><dt>R²⁵</dt><dd>C₁ to C₁₀ alkyl, C₆ to C₁₅ aryl or C₃ to C₁₀ cycloalkyl,</dd><dt>Y</dt><dd>for R²⁶R²⁷Z 〈or<chemistry id="chem0005" num="0005"><img file="EP0643084A2_D0005.tif" /></chemistry> stands,</dd></dl> in which<dl id="dl0005"><dt>Z.</dt><dd>Silicon, germanium, tin or carbon means</dd><dt>R²⁶, R²⁷, R²⁸, R²⁹</dt><dd>Hydrogen, C₁- to C₁ Alkyl-alkyl, C₃- to C₁₀-cycloalkyl or C₆- to C₁₅-aryl, where optionally two adjacent radicals together can represent cyclic groups containing 4 to 15 carbon atoms.</dd></dl> Of the compounds of the formula V, those in which<dl id="dl0006"><dt>R¹⁶ and 21</dt><dd>are the same and represent hydrogen or C₁ to C₁₀ alkyl groups,</dd><dt>R¹⁹ and R²⁴</dt><dd>are the same and represent hydrogen, a methyl, ethyl, isopropyl or tert-butyl group,</dd><dt>R¹⁷, R¹⁸, R²²</dt><dd>and R²³ are R¹⁸ and R²³ are C₁ to C₄-alkyl R¹⁷ and R²² are hydrogen or two adjacent radicals R¹⁷ and R¹⁸ and R²² and R²³ together represent cyclic groups containing 4 to 12 C atoms,</dd><dt>R²⁶, R²⁷, R²⁸ and R²⁹</dt><dd>for hydrogen or C₁ to C₈ alkyl,</dd><dt>M</dt><dd>for zirconium or hafnium and</dd><dt>X</dt><dd>stand for chlorine.</dd></dl>

Examples of particularly suitable complex compounds include 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, Ethylene bis (-2-methylindenyl) zirconium dichloride, Ethylene bis (-2-methylindenyl) hafnium dichloride, Ethylene bis (-2-methylbenzindenyl) zirconium chloride, Ethylenebis (-2-methylbenzindenyl) hafnium dichloride, Dimethylsilanediylbis (-3-tert.butyl-5-methylcyclopentadienyl) zirconium dichloride, Dimethylsilanediylbis (-3-tert.butyl-5-ethylcyclopentadienyl) zirconium dichloride, Dimethylsilanediylbis (-3-tert.butyl-5-methylcyclopentadienyl) dimethyl zirconium, Dimethylsilanediylbis (-2-methylindenyl) zirconium dichloride, Dimethylsilanediylbis (-2-isopropylindenyl) zirconium dichloride, Dimethylsilanediylbis (-2-tert-butylindenyl) zirconium dichloride, Diethylsilanediylbis (-2-methylindenyl) zirconium dibromide, Dimethylsilanediylbis (-2-methyl-5-methylcyclopentadienyl) zirconium dichloride, Dimethylsilanediylbis (-2-ethyl-5-isopropylcyclopentadienyl) zirconium dichloride, Dimethylsilanediylbis (-2-methylbenzindenyl) zirconium dichloride, Dimethylsilanediylbis (-2-methylindenyl) hafnium dichloride and Isopropylidene cyclopentadienyl fluorenyl zirconium dichloride.

The synthesis of such complex compounds can be carried out according to 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. 369 (1989), 359-370.

The metal complexes can also be in cationic form, as described in EP-A 277 003 and EP-A 277 004. Furthermore, µ-oxo-bis (chlorobiscyclopentadienyl) zirconium can also be used as the metallocene complex.

In addition to the metallocene complexes, the catalyst systems used also contain oligomeric aluminum oxide compounds. For example, open-chain or cyclic alumoxane compounds of the general formulas VI or VII are suitable<chemistry id="chem0006" num="0006"><img file="EP0643084A2_D0006.tif" /></chemistry> wherein R³⁰ is a C₁ to C₄ alkyl group, preferably a methyl or ethyl group and q 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 are described, inter alia, in EP-A 284 708 and the USA 4,794,096.

As a rule, the oligomeric alumoxane compounds obtained are mixtures of different lengths, both linear and cyclic chain molecules, so that q 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.

It has proven to be advantageous to use the complex compound of metals of subgroup IV and V of the periodic table and the oligomeric alumoxane compound in such amounts that the atomic ratio between aluminum from the oligomeric alumoxane compound and the transition metal from the complex compound of metals of IV and V. Subgroup of the periodic table is in the range from 10: 1 to 10⁶: 1, in particular in the range from 10: 1 to 10⁴: 1.

Conventional aromatic hydrocarbons are used as solvents for these catalyst systems, preferably with 6 to 20 carbon atoms, in particular xylenes and toluene and mixtures thereof.

Supported metallocene complexes can also be used. Suitable carrier materials are, for example, silica gels, preferably those of the formula SiO₂ · a Al₂O₃, in which a stands for a number in the range from 0 to 2, preferably 0 to 0.5; essentially aluminum silicates or silicon dioxide. The carriers preferably have a particle diameter in the range from 1 to 200 μm, in particular from 30 to 80 μm. Such products are commercially available, e.g. as Silica Gel 332 from Grace.

In addition to the Ziegler-Natta catalyst system or the metallocene-containing catalyst system, a second catalyst system is used according to the process of the invention, which contains as active ingredients a metallocene complex of the general formula (I) or (II) already mentioned. The process according to the invention is carried out in a reaction zone.

Preferred compounds of the general formula (I) or (II) and processes for their preparation are described, inter alia, in EP-A 537 686.

In addition to the metallocene complexes of the general formula (I) or (II), the second catalyst system used also contains oligomeric aluminum oxide compounds of the aforementioned general formula (VI) or (VII) as active constituents. With regard to the proportions of the active constituents, what has been said about the other metallocene-containing catalyst systems applies. The metallocene complexes of the general formulas (I) and (II) can also be used in supported form, it being possible to use the same supports as already described above.

The process according to the invention can be carried out both in solution, in a suspension, in the gas phase or as bulk polymerization. The process for the preparation of the multiphase homopolymers or copolymers of C₂-C₁₀-alk-1-enes is preferably carried out in the gas phase. The polymerization conditions are not critical per se; Pressures from 0.5 to 3000 bar, preferably from 1 to 80 bar and temperatures from -50 to -300 ° C, preferably from -20 to 100 ° C have proven to be suitable. The polymerization can be carried out in the presence of conventional regulators, for example hydrogen or C₂-C₈-alk-1-enes, and in conventional polymerization reactors.

In the process according to the invention, the individual catalyst systems can be used in different proportions. The proportions selected are preferably such that the polymer formed is from 5 to 70% by weight of the homo- or copolymer obtained with the metallocene-containing catalyst system of the formula (I) or (II) and from 30 to 95% by weight of the other Catalyst system obtained homo- or copolymer is composed.

With the aid of the method according to the invention, it is possible to produce multiphase homopolymers or copolymers of C₂-C₁₀-alk-1-enes in a process-technically simple manner and without great expenditure on equipment. The process according to the invention is suitable for producing a wide variety of multiphase homopolymers or copolymers of C₂-C₁₀-alk-1-enes. These can be used for the production of films, fibers or moldings and are easy to process.

Examples

example 1

1.1 Manufacture of a carrier material

56 ml of a solution of 6.4 g of triethylaluminum in 48 ml of heptane were added dropwise to a suspension of 20.2 g of silica gel (Grace, SG 332, particle diameter 20-45 μm) in 200 ml of heptane at room temperature over 30 minutes. The temperature rose to 44 ° C. After stirring for 18 hours at room temperature, the mixture was filtered, washed twice with 30 ml of heptane and twice with 30 ml of pentane and then dried in an oil pump vacuum.

1.2 Supporting the catalyst systems

To a solution of 30 ml of toluene, 40 µmol of dimethylsilanediylbis (2-methylbenzo [e] indenyl) zirconium dichloride (≙ 23 mg) and 25 µmol of rac [1,2-ethanediylbis {1- (4,7-dimethyl-4, 5,6,7-tetrahydroindenyl)}] zirconium dichloride (≙ 12 mg), 17 ml (≙ 26 mmol) of a solution of methylalumoxane in toluene (1.53 molar, from Witco) were added and the mixture was stirred for 15 minutes. 5 g of the support material prepared in 1.1 were then added and the mixture was stirred for a further 30 minutes. Finally, the solvent was removed at room temperature for 4 hours in an oil pump vacuum. A free-flowing catalyst powder formed from two metallocene catalyst systems.

1.3 polymerization

20 g of polypropylene powder and 12 ml of triethylaluminum (1 molar solution in heptane) were added in succession to a dry, 10-liter autoclave flushed with nitrogen and the mixture was stirred for 15 minutes. 1.5 g of the supported catalyst prepared in 1.2 were then introduced into the reactor in countercurrent nitrogen and the reactor was sealed. At a stirrer speed of 350 rpm, the mixture was heated to 70 ° C. and at the same time the internal pressure was gradually increased by supplying propylene to the final pressure of 28 bar. Polymerization was then carried out for 1.5 hours, with fresh propylene being fed in by the automatic pressure control. After the reaction had ended, the pressure was released to atmospheric pressure for 10 min and the resulting polymer, which consisted of two different propylene homopolymers, was discharged in a stream of nitrogen. The corresponding polymerization results are listed in the table.

Example 2

2.1 Metallocene-containing catalyst system of the formula (II)

According to the procedure described in Example 1.2, 60 μmol rac [1,2-ethanediylbis {1- (4,7-dimethyl-4,5,6,7-tetrahydroindenyl)}] zirconium dichloride (≙ 29 mg) and 16 ml of a 1st , 53 molar solution of methylalumoxane (≙ 24 mmol) in toluene.

2.2 Ziegler-Natta catalyst system

20 g SiO₂ ("SG 332" from Grace with a particle diameter of 20 to 45 microns) were suspended in 200 ml of n-heptane and treated at 20 ° C with 25.33 ml of n-butyl-n-octyl-magnesium. The suspension was heated to reflux and held at reflux for 30 minutes. After the suspension had subsequently cooled to room temperature, chlorination was carried out with excess HCl for two hours, starting at 60 ° C., and 19.41 ml of ethanol were then added at room temperature. The mixture was initially refluxed for 30 minutes and, after cooling again to 25 ° C., 17.07 ml of titanium tetrachloride were added, then the mixture was heated again to 60 ° C. and 2.94 ml of di-n-butylphthalic acid ester were added at this temperature. The mixture was refluxed for one hour. The resulting suspension was filtered and washed with 160 ml of ethylbenzene. After drying, 29.2 g of the catalyst precursor were obtained.

The catalyst precursor obtained was extracted in a heatable extraction frit with stirring for 60 minutes with a mixture of 450 ml of ethylbenzene and 50 ml of titanium tetrachloride at a jacket temperature of 125 ° C. The catalyst was then washed three times with 120 ml of n-hexane and once with 120 ml of n-pentane and dried in a stream of nitrogen. The catalyst contained 2.0% by weight of magnesium.

The titanium-containing solid component was then first subjected to prepolymerization and then inactivated. For this purpose, 700 ml of n-heptane were placed in a 1 liter glass autoclave equipped with a stirrer and the reaction vessel was cooled to an internal temperature of 5 ° C. 47.4 ml of triethylaluminum (in the form of a 1.0 molar solution in n-heptane) and 6.26 ml of dimethoxyisobutylisopropylsilane (in the form of a 1.0 molar solution in n-heptane) were added to the solvent. 20 g of the titanium-containing solid component produced were then added. With stirring, gaseous propylene flow rate: 40 l / h) was then introduced continuously at a pressure of 1 bar through an inlet tube. The internal temperature was maintained between 5 ° C and 20 ° C during the propylene feed. After the propylene had been fed in, gaseous, dry CO₂ (flow rate: 14.5 l / h at a pressure of 1 bar) was then continuously introduced into the catalyst suspension with stirring through an inlet tube. This inactivated the polymerization-active catalyst suspension.

90 g of a solid was obtained which contained 3.1 parts by weight of polypropylene per one part by weight of catalyst solid.

The resulting solid is the Ziegler-Natta catalyst system.

2.3 Polymerization

The polymerization of propylene was carried out analogously to Example 1.3 in a reaction zone in the presence of 1.3 g of the Ziegler-Natta catalyst system prepared according to Example 2.2 and 0.5 g of the metallocene-containing catalyst system described in Example 2.1. The corresponding polymerization results are listed in the table below.

Example 3

3.1 Supporting the catalyst systems

Analogously to the process described in 1.2, 25 μmol rac [1,2-ethanediylbis {1- (4,7-dimethyl-4,5,6,7-tetrahydroindenyl)}] zirconium dichloride (≙ 12 mg) were dissolved in 20 ml toluene and added to 6.5 ml (≙ 10 mmol) of a solution of methylalumoxane in toluene (1.53 molar, from Witco) and stirred for 15 minutes. 5 g of the Ziegler-Natta catalyst system prepared in 2.2 were then added and the mixture was stirred for a further 30 minutes. Finally, the solvent was removed at room temperature for 4 hours in an oil pump vacuum. A free-flowing catalyst powder was formed from a Ziegler-Natta and a metallocene catalyst system.

3.2 polymerization

The polymerization was carried out using 1.5 g of the supported catalyst prepared in 3.1 analogously to the process described in 1.3. The corresponding polymerization results are listed in the table.

Example 4

Analogously to Example 1.3, the polymerization of a mixture of propylene and ethylene was carried out in the presence of 1.5 g of the catalyst system obtained in Example 1.2 in a reaction zone and in the gas phase. The catalyst system of Example 1.2 contained both a conventional metallocene-containing catalyst system different from the formula (II) and a metallocene-containing catalyst system of the formula (II). A gaseous mixture of 99% propylene and 1% ethylene was polymerized. Appropriate regulation ensured that the selected gas composition was supplied in each case.

The melting points and glass transition temperatures of the polymer components A and B obtained were determined by means of DSC measurements (10 ° C./1 min heating rate). Two melting points and two glass transition temperatures were found for all samples, which could be assigned to two polymer components A and B. Component B was always the polymer which formed on the metallocene-containing catalyst system of the general formula (II).

The G-module was according to DIN 53 445 and the Charpy impact strength a_n determined according to DIN 53 453.

The productivities [g / g cat · h] relate to the total amount of the catalyst, ie to the sum of the amount of the two different catalyst systems.

The separation according to TREF (<u>T</u>emperature <u>R</u>ising <u>E</u>lution <u>F</u>ractionation), the respective proportions of the polymers A) [formed on the Ziegler-Natta catalyst system or on the metallocene-containing catalyst system which is different from that of the formula (I) or (II)] and that of the polymer B [formed on the metallocene-containing catalyst system of the formula (I) or (II)]. For this purpose, fractions were eluted from the entire polymer using xylene at different, increasing temperatures. The fraction obtained at 80 ° C. corresponded to polymer B, the collected fraction which was eluted at 100 ° C. and 130 ° C. corresponded to polymer A (US Pat. No. 50 30 713; L. Wild "Advances in Polymer Science "98, pages 1-47 [1990]).<tables id="tabl0001" num="0001"><img file="EP0643084A2_D0007.tif" /></tables>