SE430610B - PROCEDURE FOR THE PREPARATION OF POWDER-SHEET ETHENE POLYMERS - Google Patents

Description

I lille: I Ill; n! UIUJ ø _ '\ _ fyr:' -1 ~ u, _ .- - Va. v ¿~ r IÖÛ J W fl lim. 4 food. Furthermore, it is known that catalysts of vanadium compounds, for example vanadium oxytrichloride, vanadium tetrachloride, vanadium trichloride, vanadium dichloride or vanadic acid ester and organoaluminum compounds have only a short life and show a low productivity. Further disadvantages of these catalysts are the formation of wall coatings and lumps in the reactor during the polymerization and a completely insufficient quality of the polymer powder for processing into molded parts without prior granulation. The latter inconveniences should be obtained as a result of the formation of partially soluble complexes of vanadium and aluminum alkyl compounds in connection with the formation of catalysts according to the process belonging to the prior art.

According to the state of the art, polyolefins are processed into molded parts, such as hollow bodies, pipes, plates or foils, predominantly in the form of granules. For this purpose, the polyolefins obtained according to the Ziegler process in powder form are melted, plasticized, homogenized with ordinary confectioning agents and granulated by known methods in powder form. There has certainly been no shortage of attempts to avoid these cumbersome and costly procedures; however, no satisfactory results have been achieved. The reason for this is that the powdered polyolefins, in comparison with granules, usually have significantly smaller shrinkage sizes, significantly larger surface areas for the powder grains and often also dust particles. These undesirable properties of the powder cause the known inconveniences in their processing. Due to the low bulk densities and the moderate to poor flowability of the powder, a reduction in the discharge which can amount to up to 50% is obtained in the extrusion in comparison with granules. more. The strongly cracked surface of the powder grains causes during melting that fi small air bubbles are enclosed in the melt. This leads to incorrect or t.o.m. unusable finished parts. A blistering melt can also occur due to moisture which powder, due to its higher specific surfaces, can absorb significantly more of than granules.

The proportion of dust in the powders leads to difficulty in pneumatic transport. Thus, for example, it may be necessary to use an inert gas, such as nitrogen, instead of air, in order to exclude the danger of dust explosions caused by electrostatic charging.

On the other hand, it has now surprisingly emerged that it is possible to prepare powdered ethylene polymers which exhibit valuable technical properties using vanadium catalysts. compounds and organoaluminum compounds that exhibit high productivity and long life.

The present invention thus relates to a process for the preparation of powdered ethylene polymers with high bulk densities, good flowability, average grain diameters up to 1000 lpm and practically free from dust particles by polymerization of ethylene, optionally in admixture with small amounts of propylene or butene-1 and in the presence of hydrogen, in inert liquid hydrocarbons at temperatures between 50 ° C and about 95 ° C and pressures of 10-100 bar, preferably 20-60 bar, by discontinuous or continuous process using Ziegler catalysts, produced in inert liquid hydrocarbons by reacting chlorine- and alkoxy-containing vanadyl (V) compounds with organoaluminum compounds, separating the insoluble reaction product and activating with aluminum-alkyl compounds, which process is characterized in that 1. as vanadyl (V) -compound uses a reaction product of vanadyl (V) chloride and a vanadyl (V) alcoholate having 2-4 carbon atoms in the molar ratios of 1: 2 to 2: 1 or is directly the reaction product of vanadyl (V) -chloride with an alcohol having 2-4 carbon atoms, preferably ethanol, propanol- (1), butanol- (1) in molar ratios of 1: 2 to 1: 1 and 2. which Organoaluminum compounds for reduction use ethylaluminum dichloride and / or diethylaluminum chloride or isobutylaluminum dichloride and / or diisobutylaluminum chloride in molar ratios of aluminum-to-vanadium compound of 1: 1 to 3: 1, wherein the reaction of the vanadium compounds with the aluminum-organic compounds with stirring with specific stirring effects of 1-000 watts / m3 and 4. the activation takes place with aluminum alkyl compounds of the formula AlR3, wherein R is alkyl groups with 2-8 carbon atoms, or with alkylaluminum sesquichloride and / or alkylaluminum dichloride, in particular ethylaluminum sesquichloride and / or ethylaluminum dichloride.

As vanadyl (V) alcoholates, both those with straight-chain and also those with branched alkyl groups are in question. Alcoholates with 2-4 carbon atoms per alkyl group were used. The reaction of the vanadyl (V) chloride with the vanadyl (V) alcoholate is generally carried out in an inert liquid hydrocarbon at room temperature or even at elevated temperature.

Similarly, instead of the reaction product of vanadyl (V) chloride and vanadyl (V) alcoholate, it is also possible to directly use the reaction product of vanadyl (V) chloride with an alcohol having 2-4 carbon atoms, preferably ethanol, propanol (1) or butanol (1) in molar ratios of vanadyl (V) chloride to alcohol of 1: 2 to 1: 1, preferably 1: 1, in a hydrocarbon. 7800161-7 In the preparation of the catalyst according to the invention, both the molar ratio of vanadyl (V) chloride to vanadyl (V) alcoholate and also the molar ratios of aluminum to vanadium compound are critical.

Observing the molar ratios of the invention avoids the formation of soluble aluminum-vanadium complexes and surprisingly produces a catalyst with such a compact, even granularity that enables the preparation according to the invention of powdered ethylene polymers with excellent properties. Setting of a coarse powder grain at a simultaneous high bulk density for the powder is desirable. The average grain size of the polymer powder depends on the average particle size of the catalyst grain. The latter can be controlled according to the process of the invention by the stirring effect in the reaction of the vanadium compound with the organoaluminum compound. Higher specific agitation effects lead to a finer catalyst grain than lower and consequently under equal polymerization conditions to a smaller average grain diameter of the polymer.

It was completely surprising and not in any way predictable that the use of the process according to the invention in the catalyst preparation would enable such a technical advance which could be realized with regard to the preparation of powdered ethylene polymers. The use of the new catalysts according to the process of the invention takes place in a manner known per se under the usual conditions for low-pressure polymerization according to Ziegler, as already stated above. Due to the fundamentally high productivity of the catalysts according to the invention, measures for removing the catalysts from the polymers are not required.

When using the direct reaction product of vanadyl (V ¥ chloride and alcohols, it has the further special advantage that the expensive production of chlorine-free vanadyl (V) alcohols can be dispensed with and instead of a reaction product of vanadyl (V) - Alcohol with vanadyl (V) chloride A chlorine-containing reaction mixture of vanadyl (V) chloride with an alcohol is readily obtained The reaction of the vanadyl (V) chloride with the alcohol is conveniently carried out in an inert liquid hydrocarbon at room temperature or at room temperature. elevated temperature, whereby depending on the reaction conditions more or less hydrogen chloride is emitted, for example when using a liquid inert hydrocarbon with a boiling range of approximately 60-80 ° C at several hours heating under reflux it in the reaction 7800161-7 of vanadyl (V) The chloride with the alcohol liberated the hydrogen chloride almost quantitatively, but for the process according to the invention the proportion of hydrogen chloride remaining in the reaction mixture is e not of significant importance. Suitable alcohols are saturated, monohydric alcohols having straight-chain or branched alkyl groups having 2 to 4 carbon atoms. The best results regarding as high a catalyst activity as possible are achieved with primary, monohydric, straight-chain alcohols. With regard to high bulk densities, dust freedom and good flowability of the polymer powder, particularly good results are obtained when using ethanol, propanol (I) and hutano% (1). At higher carbon atoms for the alcohols than H, with increasing chain length, finer powders are increasingly obtained which are less desirable for processing into finished load parts.

The vanadium-containing catalyst component prepared according to the invention, insoluble in liquid hydrocarbons, can be activated both with halogen-free and also with halogen-containing aluminum-organic compounds. In all cases, polymerization of ethylene under the above conditions gives polymer powder of excellent quality in terms of flowability, bulk density and dust freedom.

When using halogen-free organometallic compounds, such as trialkylaluminum, for activating the vanadium-containing catalyst component according to the invention, polymers with a broad molecular weight distribution are obtained, which are particularly suitable for processing by extrusion process into films, plates, hollow bodies, pipes and profiles. On the other hand, when using halogen-containing organoaluminum compounds, such as ethylaluminum sesquichloride and / or ethylaluminum dichloride, polymers with a narrower molecular weight distribution are obtained which are particularly advantageous for the production of injection molded articles.

As is known, injection molded articles of low pressure polyethylene with a narrow molecular weight distribution for the polymer have a number of advantages over such polymers with a broad molecular weight distribution, for example lower warping tendency, high stack load capacity and good usability even at very low temperatures.

For activation, one can use both ethylaluminum dichloride and / or diethylaluminum chloride as well as isobutylaluminum dichloride and / or diisobutylaluminum chloride.

Isobutylaluminum dichloride is distinguished from the corresponding ethylaluminum compound in the technical implementation of the process according to the invention in that it has a lower melting resp. solidification point and better solubility in liquid hydrocarbons at low temperatures. The isobutylaluminum dichloride has a melting point of -30 ° C while ethylaluminum dichloride solidifies already at + 320C (Ullmann's Encyclopädie der technischen Chemie, fourth edition, volume 7, page EHH, Verlag Chemie GmbH, 1973). Consequently, heating of the storage tank and pipelines is not required other than with ethylaluminum dichloride.

The powdered polyethylenes resp. By means of the process according to the invention resp. the copolymers of ethylene and small amounts of propylene or butene- (1) are suitable according to their molecular weight setting and the composition of the catalyst used for their preparation according to the invention for use in the injection molding or extrusion sector. The powders prepared according to the invention have high bulk density values of about 0.420 to 0.550 g / ml (DIN 53 468) and are practically free of dust particles. They show excellent flowability.

The flow rates according to the draft DIN 53 492 when using an outlet opening with a diameter of 10 mm amount to 6 to 10 cm3 / sec. With the powders prepared according to the invention, in their processing as plastics, the greater throughput resp. ejection performance the larger the average grain diameter, as shown in the following table. The average grain size d 'is determined from the RRSB distribution function (DIN 66 145). d 'is defined according to this so that 36.8% by weight of the powder has a larger grain diameter than 4'.

Average grain size d 'Throughput during processing to 10-1- um-hole bodies kg / h 1-00 87.0 680 99.5 820 105.0 Of course, the numerical values given in the table for throughput resp. ejection performance under equal circumstances measured comparative figures whose absolute value and possibly also their relation are largely dependent on the processing machines.

Depending on the molecular weight distribution, the molded powders according to the invention can be processed without objection to molded parts, such as injection molded articles or extruded articles, for example pipes, plates, profiles, hollow bodies and foils. Thanks to the compact grain structure, the melt is practically free from v. Ygnqmgynfmw e. -Na 7800161-7 blisters. Preferably, the coarser powders of the powders according to the invention are used because in their total ratio in the plastic processing they are most similar to the granulate.

The process of the present invention is further illustrated by the following examples.

Example 1. n) Vatalyst preparation. 122.5 g (705.7 mmol) of vanadyl (V) -chloride and 172.5 g (705.7 mmol) of vanadyl (V) -n-propylate were heated together in 1.7 l of a hexane-fractin 63/80 After cooling the mixture, a solution of 3HO, 3 U (2,822.6 mmol) of diethylaluminum chloride, μl of the hexane fraction 63/80 ° C was added at 20 to 25 ° C within 2 hours with stirring. with a blade stirrer and a specific stirring power of 126 watts / nä. The resulting suspension was then stirred for an additional 2 hours at 55 ° C with the same specific stirring effect. After cooling, the solid was separated and washed 5 times with 5 liters each of the hexane fraction. b) Polymerization of ethylene.

In a 2 liter steel autoclave, 1 liter of a hexane fraction 63 / 809C and 0.1 g of triisobutylaluminum was preloaded under nitrogen.

To this was added 30 mg of the catalyst prepared according to Example 1a, suspended in a few ml of the hexane fraction. After the displacement of the nitrogen by ethylene, 6.3 bar of hydrogen was pressed in and then ethylene to a total pressure of 31.1 bar. At the same time, the reactor contents were heated to 7500. The polymerization was carried out for 1 hour with stirring with a stirring speed of 1,000 min.l at 7500, the total pressure being maintained by reprinting ethylene.

The reactor was then released from pressure, the polyethylene formed was filtered off after cooling the reactor contents and dried. The yield of polyethylene was 356 g, which corresponded to 11.9 kg per g of catalyst. The iron size d 'amounted to 610 μm. The bulk density according to DEN Rf fl ßß to 0, ü60 g / ml, the flow time according to DIN draft 53 H92 at an outlet opening with a diameter of 10 mm to 16.6 sec., Corresponding to a flow rate VR 10 of 9.31 cm 2 / sec.

Example 2. a) Catalyst preparation The same procedure as in Example 1a was used, except that a solution was added instead of the diethylaluminum chloride solution; of f * =, 7 g (,, 220 mol) of ethylaluminum dichloride in 2.27 liters of hexane 'actic: a 63 /? Û ° C for reaction with a mixture of 192.8 7800161-7 (1.055 mol) vanadyl (V) chloride and 257.6 g (1.05 mol) of vanadyl (V) -n-propylate in 1.77 liters of the hexane fraction b) Polymerization of ethylene.

The same procedure as in Example 1b was used, except that 20 mg of the catalyst prepared according to 2a were used instead of the catalyst prepared according to 1a. The yield of polyethylene was 221 5, corresponding to 11.1 kg per g of catalyst. The grain size d 'was H80 μm, the bulk density according to DIN 53 H69 to 0, H3O g / ml, the flow time according to DIN draft 53 H92 at an outlet opening with a diameter of 10 mm to 19.4 seconds, corresponding to a flow rate VR lo of 8 .05 cmš / sec.

Comparative Example 1. a) Catalyst preparation.

In the manner described in Example 1a, a mixture of 27U, 3 g (1,583 mol) of vanadyl (V) chloride and 128.9 g (0.528 mol) of vanadyl (V) -n-propylate (molar ratio of chloride / alkoxide = 3: 1 .mu.l of the hexane fraction 63/80 ° C with 535.7 3 (H, 220 mol) of ethylaluminum dichloride in 2.25 l of the hexane fraction. b) Polymerization of ethylene.

With 15 mg of this catalyst, an ethylene polymerization was carried out in the same manner as described in Example 1b. The yield of polyethylene was 173 g, corresponding to 11.5 kg per g of catalyst. The grain size d 'was only lü0 um. The bulk density according to DIN 53 H68 only to 0.200 g / ml. The running time according to DIN draft 53 H92 at an outlet opening with a diameter of 10 mm to 106.6 seconds, corresponding to a running speed VR lø of 1, H? cmj / sec.

Comparative Example 2.

II catalyst preparation. 9.67 g (50 mmol) of vanadyl (V) -chloride and 12.21 g (50 mmol) of vanadyl (V) -n-propylate were heated together in 95 ml of a hexane-Praktien 63/8000 under nitrogen for 2 hours during reflux. After cooling the mixture, a solution of 76.17 g (500: mol) of ethylaluminum dichloride (molar ratio AIJV compounds = = 6: 1) in 352 ml of the hexane fraction 63/8000 was added at 25 ° C within 2 hours with stirring. with a specific stirring power of N00 watts / Uf. The resulting suspension was then heated for a further 2 hours under reflux and stirred with the same specific stirring efficiency, whereby the first precipitate formed was dissolved.

L) Polymerization of ethylene.

With 5 ml of this catalyst solution (containing 1 mmol of crude oil) and 2 g of triisobutylaluminum, an ethylene polymerization was carried out in the same manner as described in Example 1b. The yield of polyethylene amounted to H1 5. Very strong growth of polymer was formed on the autoclave wall and on the stirrer.The polymer had no grain structure and was baked together into lumps.The bulk density according to DIN 53 H6 * was only 0.110 g / ml.

Example 3. a) Catalyst preparation. 8.67 g (50 mmol) of vanadyl (V) -chloride and lu, 32 g (50 mmol) of vanadyl (V) -iso-butylate were heated together in 85 ml of a hexane fraction 65/80 ° C under nitrogen in 2 hours under reflux. After cooling the mixture, a solution of 25.0 g (200 mmol) of ethylaluminum dichloride in 118 ml of the hexane fraction 63/80 ° C was added at 2500 over 2 hours with stirring with a blade stirrer and a specific stirring effect of H00 watts / m 3 . The resulting suspension was then heated for a further 2 hours under reflux and stirred with the same specific stirring effect. After cooling, the solid was separated and washed 5 times with 500 ml each of the hexane fraction. b) Polymerization of ethylene.

With 10 g of this catalyst, an ethylene polymerization was carried out in the same manner as described in Example 1b and with a hydrogen partial pressure of 1.6 bar. The yield of polyethylene amounted to 18U g corresponding to 18.1 H kg per g of catalyst. The grain size d 'amounted to N60 μm, the bulk density according to DIN 55 H68 to 0,75 g / ml, the flow time according to DIN ~ draft 53 H92 at an outlet opening with a diameter of 10 mm to 19.8 seconds, corresponding to a flow rate VR lo of 7 , 99 cmš / sec.

Example U.

In a 750 ml stirring reactor, the vanadium catalyst described in Example 1a was used for continuous polymerization of ethylene.

The polymerization took place in suspension; as suspension medium: a hexane fraction is used in the boiling range between 6300 and 80 ° C. The pellet height in the polymerization reactor was 500 l, as the average residence time for the catalyst in the reactor was selected to be H hours. The nitrous oxide: F = HO-ntr? Lbarrier is connected with a double ball valve distance.

The polymerization was carried out at a temperature of * E ° C.

The partial pressure in the gas chamber of the reactor amounted to Él, 9 bar.

Hydrogen was used for molecular weight control; The hydrogen partial pressure in the nao ~ space of the reactor amounted to 3.2 bar. Triisobutylaluminum was used as cocatalyst. Catalyst and cocatalysts were diluted in a stirring vessel in hexane 63/8000 and fed continuously to the reactor with a diaphragm pump. The concentration of the catalyst in the polymerization vessel was 9.33 mg / l of suspending agent and the concentration of the cocatalyst was 100 mg / l of suspending agent. The speed of the stirrer in the polymerization reactor was set to 150 min._1. The powdered polymer formed in the reactor was separated on a centrifuge from suspending agent and dried in a partially evacuated container at about 7 ° C. Under these experimental conditions, with the catalyst described in Example 1a), a polymer was obtained which exhibited the following properties: Melt index MFI 190/5 according to DIN 53 735 29 8/10 min.

Concentration-related relative viscosity change I according to DIN 55 728 150 cmi / g Average molecular weight 55,000 Density at 23 ° c according to DIN 53 1479 0.969 g / em3 Total ash 60 ppm Ash analysis 26 ppm Al2O5 17 ppm v2o5 10 ppm chlorine The numerical catalyst consumption for this driving consumption , 7 mg vanadium catalyst / kg polyethylene and 620 mg triisobutylaluminum / kg polyethylene. The polymer powder prepared in this way had an unusually high bulk density according to DIN 53 H68 with 0.550 g / ml. The needle grain size d 'was 750 μm; when determining the flowability according to DIN draft 55 H92, the powder had an expiration time tR 10 of only 15.6 seconds. This corresponds to a flow rate VR 10 of 10.02 cm3 / sec.

Example 5.

The catalyst described in Example 1a) was used in the same apparatus for the continuous polymerization of ethylene in admixture with propylene. Addition of 10% by weight of propylene, calculated on the amount of ethylene added per hour, in comparison with homopolymerization produced a clear reduction of the average molecular weight. Thereby, the desired average molecular weight could be set with a hydrogen partial pressure of only 1,? bar in the gas space of the reactor. The ethylene partial pressure was ïï9. The minimum cooling time for the catalyst in the reactor is up to 3 hours. Catalyst concentration set n? 9.7 mg vanilla catalyst / 1 suspending agent and 100 mg triisobutylaluminum liters. With this mode of driving a polymer was obtained with the following characteristics; 780016? -7 ll Melt index MFI 190/5 according to DIN 53 735 31 g / 10 min. Concentration due to relative viscosity change I according to DIN 53 728 150 cm3 / g Heavy molecular weight 55,000 Density at 23 ° C according to DIN 53 H79 0.953 s / cm3 Total ash 50 ppm Ash analysis 22 ppm Al 2 O 3 10 ppm V 2 O 5 10 ppm chlorine The numerical catalyst consumption 22 mg consumption vanadium catalyst / kg polyethylene and 530 mg triisobutylaluminum / kg polyethylene. The bulk density according to DIN 53 H68 for the polymer powder was 0.501 g / ml. The average grain size d 'was 570 μm; the powder had an expiration time tR 10 of 22.2 seconds when determining the flowability, corresponding to a flow rate VR 10 of 7.0ü cm3 / sec.

Example 6.

The catalyst described in Example 2a) was continuously polymerized in the apparatus already described in ethylene. The hydrogen partial pressure in the gas space of the reactor was set at 2.5 bar; ethylene partial pressure amounted to 32.5 bar. The catalyst concentration in the polymerization reactor was H mg of vanadium catalyst / liter of suspending agent and 100 mg of triisobutylaluminum / liter of suspending agent. The average residence time of the catalyst in the reactor was chosen to be 2 hours. Thereby, polyethylene with the following properties was obtained: Éïëltindex NFI 190/5 - according to DIN 53 755 0, Hl g / 10 min.

Concentration-related relative viscosity change I according to: In S3 122 too cm3 / g Û fi ñel molecular weight I? 8,000 Density at EBOC according to K III 55 P19 0.959 g / cm 'Total ash HO ppm Ls analysis 22 ppm A1205 lä ppm V2O5 10 ppm chlorine catalyst Den The crude density of the polymer powder was 78 DEG C., 161 DEG-12 DEG-12 DEG to 12 DEG C., respectively, and the average grain size of the polymer was low at 6 DEG. had in determining the flowability an outlet time tR 10 of 18.2 seconds, corresponding to a flow rate VH lo of P, r ° rm * / sec.

Example 7.

In the semi-technical polymerization apparatus of Example U, the catalyst of Example 2a was used to polymerize ethylene in admixture with propylene. The ethylene partial pressure in the gas space of the reactor was 3U, 1 bar; the hydrogen partial pressure was 0.9 bar; propylene was added in comparison with ethylene in a weight ratio of 6 to 100.

The catalyst concentration was 3.3 mg of vanadium catalyst / liter of suspending agent. The average residence time of the catalyst in the reactor was 2 hours. Under these experimental conditions, polyethylene with the following properties was obtained: Melt index MFI 190/5 according to DIN 53 735 0.30 g / 10 min.

Concentration-related relative viscosity change I according to DIN 53 728 D10 cm / g Base molecular weight 183,000 Density at 2o ° c according to 3 DIN 53 H79 0.949 g / cm Total ash H0 ppm Ash analysis 18 ppm Al 2 O 3 ll ppm V2O5 10 ppm chlorine The numerical determination of catalyst in this example was 37 .mu mg of vanadium catalyst / kg of polyethylene and 1,120 mg of triisobutylaluminum / kg of polyethylene. The polymer powder had a bulk density of 0.175 g / ml, the average grain size was GHO 3. When determining the flowability according to DIN draft 53 H92, an expiration time tR 10 of 18.9 seconds was measured. This corresponds to a flow rate of VR lo of 8.27 cmz / sec.

Example 8.

In the same manner as described in Example 7, ethylene was polymerized in admixture with 6% by weight of butene-1. The polymer thus obtained had the following properties: 7800161-7 13 Melt index MFI 190/5 according to DIN 53 735 0, HO g / 10 min.

Concentration due to fi relative viscosity change I according to X DIN 53 723 H10 cm '/ g Lower molecular weight 183,000 Density at 20 ° C according to DIN 53 479 0.950 g / cm5 Total ash 50 ppm 2? ppm Al 2 O 3 12 ppm V 2 O 5 10 ppm chlorine The numerically determined catalyst consumption was 33.8 mg vanadium catalyst / kg polyethylene and 1,020 mg triisobutylaluminum / kg polyethylene. The powder had a bulk density of 0.82 g / ml, the average grain size d 'was 660 μm. The expiration time tR 10 for the powder when determining the flowability amounted to 18.2 seconds, corresponding to a flow rate VR 10 of 8.59 cm3 / sec.

Example 9. a) Catalyst preparation.

The same procedure as in Example 2a was used, except that the stirrer had a specific stirring power of 3,400 watts / m '. b) Copolymerization of ethylene and butene-1.

The catalyst described in Example 9a) was used in the semi-technical apparatus for the continuous polymerization of ethylene in a mixture with 3% by weight of butene-1. Reactor temperature, mean residence time in the reactor and hydrogen and ethylene partial pressures were as high as in Example 7. The concentration of the vanadium catalyst in the reaction vessel was H mg / l; the concentration of triisobutylaluminum was as high as in Example 7. The polymer prepared in this way had the following properties: Melt index MFI 190/5 according to DIN 53 735 0.50 g / 10 min.

Concentration-related relative viscosity change I according to DIN 53 728 390 cm3 / g Hedel molecular weight 172,000 nensity at 2o ° c according to 3 DIN 53 H79 0.956 g / cme Total ash MO ppm Ash analysis 21 ppm A12O¿ ll ppm V205 10 ppm chlorine 7800161-7 numerically determined catalyst consumption was U9.5 mg vanadium catalyst / kg polyethylene and 1,230 mg triisobutylaluminum / kg polyethylene. The polymer powder had a bulk density of 0.1 H92 g / ml; the average grain size d 'was H30 μm. When determining the flowability, a rise time of tR 10 of 2H, 7 seconds was measured.

This corresponds to a flow rate of VR lo of 6.33 cm3 / sec.

Example 10. a) Catalyst preparation.

The same procedure was used as in Example 2a, except that stirring was performed with a specific stirring power of 5 watts / m3. b) Copolymerization of ethylene and butene-1.

Ethylene was continuously meriserized in a mixture with 3% by weight of butene-1. The hydrogen partial pressure was 0.7 bar; the ethylene partial pressure in the gas space of the reactor was 3U, 3 bar. The vanadium catalyst was provided at a concentration of 2.7 mg / liter of suspending agent.

The concentration of the cocatalyst triisobutylaluminum was as high as indicated in Example 7. A polymer prepared in this way had the following properties: Melt index MFI 190/5 according to DIN 53 735 0.35 g / 10 min.

Concentration-related relative viscosity change I according to DIN 53 728 390 cm3 / g Average molecular weight 172,000 Density at 20 ° C according to DIN 53 H79 0.952 g / cm3 Total ash 70 ppm Ash analysis 35 ppm Al2O3 8 ppm V2O5 The numerical catalyst consumption of kg of catalyst was 27 kg polyethylene and 1,080 mg triisobutylaluminum / kg polyethylene. The polymer powder had a bulk density of 0.023 g / ml; the average grain size d 'was 960 μm. When determining the flowability according to DIN draft 53 H92, the expiry time was t? lo to 2U, 7 seconds; this corresponds to a flow rate VR 10 of 6.33 cm / sec.

Example ll. a) Preparation of the vanadium-containing catalyst component 1 ° P, 9 P (1,055 mol) of vanadyl (V) chloride and 2 7 á 1 Qff »s = \ 5, Q (, _ U.-? 8Û0161 *? vanadyl (V) -N-propylate was heated together in 1.7 liters of a hexane fraction 63/8000 under nitrogen for 2 hours to 5500. After cooling the mixture, a solution of 535.7 g (H, 220 mol) was added at 20-2500 ) ethylaluminum dichloride in 2.27 liters of the hexane fraction 63/80 ° C within 2 hours with stirring with a blade stirrer and a specific stirring power of 125 watts / nl. The resulting suspension was then stirred for a further 2 hours at E5 ° C with the same specific stirring effect. the solid was separated and washed 5 times with 5 liters each of the hexane fraction b) Polymerization of ethylene.

In a two liter steel autoclave, 1 liter of a hexane fraction 63/8000, 25 [mu] g (2 mmol) of ethylaluminum dichloride and 15 mg of the catalyst component prepared according to Example 1a, suspended in a few ml of the hexane fraction, were charged under nitrogen. This mixture was stirred for 30 minutes at room temperature. Thereafter, after the displacement of nitrogen through ethylene, 1.6 bar of hydrogen was pressed and in connection therewith ethylene up to a total pressure of 31.1 bar. At the same time, the reactor contents were heated to 7500. The polymerization was carried out for 1 hour with stirring at a stirring speed of 1,000 min.l at 7500, the total pressure being maintained by repression of ethylene.

Then the reactor was released from pressure, the polyethylene formed was filtered off after cooling the reactor contents and dried. The yield of polyethylene was 292 g, corresponding to 19.5 kg per g of catalyst.

The needle grain size d 'amounted to 590 μm, the bulk density according to DIN 55 H68 to 0.335 g / ml, the flow rate VR lo to 3.68 cmš / sec.

(DIN draft 53 H92). The viscosity number according to D§N 55 728 amounted to H00 cm3 / g. The molecular non-uniformity (fi w / Mn - 1) was determined gel chromatographically to U, 6, the proportion of 4 Üw / 5 to 25, U ä.

Example 12. a1 Preparation of the vanadium-containing catalyst component. 1.2 g (1.05 mol) of vanadyl (V) chloride and 257.6 g (1.05 mol) of vanadyl ("} - n-propylate were stirred together in 1.66 liters of a hexane fraction G3 / 9000 for 1 hour at room temperature This mixture and a solution of 535.7 g (μ, 22 mol) of ethylaluminum dichloride in 2.30 liters of the hexane fraction 63/8000 were added synchronously within 2 hours at 2500 to 2 liters of the hexane fraction while stirring with a stirrer and a specific stirring power of 1000 watts / m3.

The resulting suspension was then heated for a further 2 hours under reflux and stirred with the same specific stirring effect. After cooling, the solid was separated and washed 5 times with 7 liters each of the hexane fraction. b) Polymerization of ethylene.

The vanadium-containing catalyst component described under 12a was used with ethylaluminum sesquichloride in a 750 ml stirring reactor for continuous polymerization of ethylene. The polymerization took place in suspension; as the suspension medium, a hexane fraction was used in the boiling range between 63 ° C and 80 ° C. Filling level in the polymerization reactor was 300 liters, the average residence time of the catalyst in the reactor was 2 hours. The leveling in the polymerization reactor took place via a Co-60 jet barrier connected to a double ball valve track. The polymerization was carried out at a temperature of 75 ° C.

The ethylene partial pressure in the gas space of the polymerization reactor amounted to 30.6 bar. Hydrogen was used for molecular weight control of the polymer; the hydrogen partial pressure in the gas space of the reactor amounted to U, U bar. The vanadium-containing catalyst component and ethylaluminum sesquichloride were diluted in a stirring vessel in hexane 53/80 ° C and fed after a mean residence time of 0.5 hours with a diaphragm pump continuously to the reactor. The concentration of the vanadium-containing catalyst component in the polymerization vessel was 7.33 mg / liter of suspending agent and the concentration of ethylaluminum sesquichloride was 100 mg / liter of suspending agent.

The speed of the agitator in the polymerization reactor set: to 150 min._l. The powdered polymer formed in the reactor was separated from a suspending agent in a centrifuge and dried in a partially evacuated container at about 80 ° C. Under these experimental conditions a polymer was obtained which exhibited the following properties: Melt index NFI 190/5 according to DIN 53 735 1.7 3/10 min.

Viscosity number In accordance with DIN 53 728 300 cm fi / 5 Lower molecular weight 126,000 Density at 2a ° c according to DIN 53 H79 0.959 g / cm3 Molecular_uniformity u (U = MW / Mn -1) H, 3 molecular weight fraction << fi w / 5 25.6 ß Consumption of vanadium-containing catalyst component in this mode of operation amounted to 72.2 mg / kg of polyethylene and of ethylaluminum sesquichloride to 985 mg / kg of polyethylene. The polymerate powder prepared in this way had a bulk density determined in accordance with DIN 55 H68 of 0.135 g / ml. The average grain size d 'was 300 μm; the powder had a flow rate VR 10 = 7.2 cm; / sec., determined according to the DIY draft wä flflfifi ülimnmwdMwww flfi w fi ww fl * wc «~~~ 'W” 7800161-7 17 53 Ü92- Example 13. a) Preparation of the vanadium-containing catalyst component.

The same procedure as in Example 12a was used, except that stirring was performed with a specific stirring power of 126 watts / m3. b) Polymerization of ethylene.

In the polymerization apparatus described in Example 12b, a vanadium-containing catalyst component prepared according to Example 13a with ethylaluminum sesquichloride was used for continuous polymerization of ethylene. An ethylene partial pressure of 31 bar was set in the gas space of the polymerization reactor; the hydrogen partial pressure there amounted to H bar. The concentration of the vanadium-containing catalyst component in the polymerization reactor was 6.7 mg / liter of suspending agent; the concentration of ethylaluminum sesquichloride was unchanged in relation to, for example, 12 b. With this mode of driving a polymerate was obtained with the following properties: Melt index MFI 190/5 according to DIN 53 735 2.9 5/10 min. Icosity number I '3 = according to Dir-I 53 728 2110 cm / g Average molecular weight 97,000 É Density at 23 ° C 3' according to DIN 53 N79 0.950 g / cm Molecular non-uniformity U (U = MW / Mn-1) 6.5. Molecular weight ratio (HW / S 30.1: Under the experimental conditions described, the enrichment of the vanadium-containing catalyst component amounted to 68.7 mg / kg of polyethylene and of the ethylaluminum sesquichloride to 1,050 mg / kg of polyethylene.

The polymer powder had a bulk density according to DIF 53 H68 of 0.325 g / ml. The average grain size d 'was 5: 0 μm; When determining the flowability according to DIN draft 5, the polymerisate powder had 5? H92 a flow rate VR 10 = 8, U cm; / sec. example lh. a) Preparation of the vanadium-containing catalyst component: a.

The same procedure as in Example 11a was used, except that instead of the ethylaluminum dichloride solution a solution of 3U0.5 V (? 922.6 mmol) of diethylaluminum chloride II, H3 1 of the hexane fraction 63/9000 was used for reaction with a mixture of 129 (3 '(05.7 mmol) of vanadyl (V chloride and 172.3 g (? O5.7 mmol) of vanadyl (V) -n-propylate in 1.7 liters of the hexane fraction 63/3000. 7800161-'7 18 b ) Polymerization of ethylene.

The vanadium-containing catalyst component described under 1 "a was used in the apparatus for continuous polymerization of ethylene described in Example 12b. At a filling level in the polymerization reactor of 300 liters, an average residence time of the catalyst in the reactor of H hours was selected. The vanadium-containing catalyst component was diluted. as described in Example 12 b, in a stirring vessel in hexane 63/8000, before it was introduced into the polymerization vessel, the concentration J of the polymerization reactor was 16 mg / liter of suspending agent Ethylaluminum sesquichloride was pumped from a storage vessel directly into the polymerization reactor where a concentration of 100 mg / liter of suspending agent was maintained.

The ethylene partial pressure in the gas space of the reactor amounted to 52 ,? bar. For molecular weight control, hydrogen up to a partial pressure of 2.3 bar was forced into the gas space of the reactor. Using the procedure described here, a polymer was prepared with the following properties: Melt index MFI 190/50 according to DIN 53 735 Viscosity number I according to DIN 53 728 Average molecular weight Density at 2300 according to DIN 53 H79 Molecular non-uniformity U (U = MW / Mn-1) Molecular weight fraction - 1.9 g / 10 min. 250 cmš / g 102,000 0.956 g / cm3 5, H 25.8% The consumption of vanadium-containing catalyst component was 97, Ä mg / kg polyethylene and of ethylaluminum sesquichloride to 620 mg / kg polyethylene. The bulk density of the polymer was 0, UHO g / ml . The powder had an average grain size d '= 79011m and when determining the flowability a flow rate of Vä lo of 9.2 cmš / sec.

Example 15.

With 10 mg of the catalyst component prepared according to Example 11a, an ethylene polymerization was carried out in the same manner as described in Example 11b, but with the addition of 310 mg (2 mmol) of isobutylaluminum dichloride instead of ethylaluminum dichloride and refraining from the pre-reaction for 30 minutes. between the vanadium-containing catalyst component and the organoaluminum compound. The yield of polyethylene upnnick to l6N q .en, corresponding to l6, U kg per gram of catalyst. The molecular non-uniformity was determined gel chromatographically to P, 6, the ratio of 4 kw / 5 to 26.7 s.

Auf * - 7800161-'7 19 Example 16. so Catalyst preparation no. 6.6 g (2 moles) of vanadyl (V) chloride and 180.3 S (3 moles) of Dropanol - (1) were heated together in 1.59 liters of a hexane fraction 63 / BOOC for 2 hours under reflux, hydrogen chloride resigned.

Then this mixture and a solution of 507.8 g (U mol) of ethylaluminum dichloride in 2.25 liters of the hexane fraction 63/8000 were added synchronously within 2 hours to 2 liters of the hezane fraction at 28 ° C under nitrogen and with stirring with a blade stirrer. and a specific stirring power of 95 watts / m3. The resulting suspension was then heated for a further 1 hour under reflux and thereby with the same specific stirring effect. After cooling, the solid was separated and washed 5 times with 5 liters each of the hexane fraction. b) Polymerization of ethylene.

The vanadium catalyst described in Example 16a was used in a 750 liter stirred tank for continuous polymerization of ethylene. The polymerization of ethylene took place in a suspension of a hexane fraction in the boiling range between 63 ° C and 80 ° C and powdered polyethylene and catalyst. The filling level in the polymerization vessel was set at 300 liters; as the average residence time of the catalyst in the polymerization vessel, 2 hours was chosen.

The polymerization was carried out at a temperature of 7500. The ethylene partial pressure in the gas space of the polymerization vessel was 3.11 bar. Hydrogen was used to control the average molecular weight; the hydrogen partial pressure in the gas space of the polymerization reactor amounted to 0.9 bar. Triisobutylaluminum was used as the cocatalyst for activation. The catalyst and cocatalyst were diluted in a stirring vessel in hexane 63/80 ° C and fed continuously to the polymerization vessel with an aosizing pump. The concentration of the catalyst in the polymerization tank was 3.33 mg / liter of suspending agent and the concentration of the cocatalyst was 100 mg / liter of suspending agent. The speed of the stirrer in the polymerization vessel was 150 minutes -1. The polymeric polymer formed in the reactor was separated from the slurry in a centrifuge and dried in a partially evacuated container at about 80 ° C. Under these conditions a polymer was obtained with the following properties: Particle molecular weight 178,000 Fneltine index HFI 190/5 according to 91 "23 735 0, H6 g / 10 min. 780Û161 ~ 7 20 viscosity extract I according to DIN 55 723 Density: lm 2350 according to DIN 53 H79 Molecular inconsistency U (U = MW / Mn-1 Molecular weight ratio -éñw / 5 Total ash H00 cm3 / g 0.956 g / cm3 22.2 ng, g HO ppm The numerical catalyst consumption in this case amounted to U5.9 mg vanadium catalyst / kg polyethylene and 1,380 mg of triisobutylaluminum / kg of polyethylene, according to DIN 53 H68, the polymer powder had a bulk density of 0.509 g / ml, the heat grain size d 'was 595 μm;

: R 10 of 9,? cm; / sec.

In the same apparatus as described in Example 16b, the catalyst of Example 16a was used for the continuous polymerization of ethylene with the addition of small amounts of butene- (1). The ethylene partial pressure in the gas chamber of the polymerization reactor was 3P, 3 bar; The hydrogen partial pressure there was 0.7 bar. Butene (1) was provided in comparison with ethylene in the weight ratio of 2 to 100. The catalyst concentration in the reactor, cocatalyst and cocatalyst concentration in polymerization reactor, reactor temperature, average residence time of the catalyst in the polymerization reactor were unchanged in relation to, for example, 16 b. Under these conditions, a copolymer was prepared which exhibited the following properties: ïdelm molecular weight Melt index MFI 190/5 according to DIÜ 53 735 Tiskosity number I according to DIN 5? 729 Density at 23 ° C according to DIN 53 H79 ïolekglër inconsistency U (U = MW / than-1) Hole molecular weight <Üw / 5 Tøtal ash Ash analysis 169,000 O, H8 g / 10 minutes 530 cmñ / 5 C, 95H 5 / cm3 l fl ppm AIQO3 10 ppm Y, O (10 ppm chlorine, »,« e | p .. fl w, .. ,,., V, ._ l ,,. Ul _. .In, '7800161-'7 21 The numerical catalyst consumption was to U8.6 mg vanadium catalyst / kg polyethylene and 1.30 mg mg triisobutylaluminum / kg polyethylene The bulk density of the polymer according to DIN 53 H68 was 0.096 g / ml, the average powder grain size d 'was found to be SUO Um

When determining the flowability according to DIN draft 53 D92, a flow rate VR 10o for the polymer of 9.0 cm 3 / sec was obtained.

Example 18 3 Kata] vsatcgrírïalnstäl lning. 17.33 g (0.1 mol) of vanadyl (V) chloride and 11.1 g (0.1 mol) of butanol (1) were stirred together in 80 ml of a hexane fraction 63/80 ° C for 2 hours at room temperature. . Then this mixture and a solution of 25.39 g (0.2 mol) of ethylaluminum dichloride in 112 ml of É of the hexane fraction 63/8000 were added synchronously within 2 hours at 25-3C ° C to 100 ml of the hexane fraction under nitrogen and with stirring. with a blade stirrer and a specific stirring power of 300 watts / m2. The resulting suspension was then heated for a further 2 hours under reflux, stirring with the same specific stirring effect. After cooling, the solid was separated and washed with a total of 2 liters of the hexane fraction. b) Polymerization of ethylene.

In a two-liter steel autoclave, 1 liter of a hexane fraction 63/8000 and 0.1 g of triisobutylaluminum were pre-charged under nitrogen.

To this was added 15 mg of the catalyst prepared according to Example 18a, slurried in a few ml of the hexane fraction. After displacing nitrogen through ethylene, 6.3 bar of hydrogen was pressed in and then the e up to a total pressure of 31.1 bar. At the same time, the reactor contents were heated to 75 ° 0. The polymerization was carried out for 1 hour with stirring at a stirrer speed of 1,000 minutes -1 at 75 ° C, the total pressure being maintained by reprinting ethylene.

Thereafter, the reactor was released from pressure, after cooling the reactor contents, the polyethylene formed was filtered off and dried. The yield of polyethylene was 326 g corresponding to 21? kg per g of catalyst. The particle size d 'was 560 Pm, the bulk density according to: IN 53 1:68 to 0.2: 1 g / ml, the flow rate VR lo to 7.1: cnß / sec.

(DIN draft 53 N92). The viscosity number according to DIN 53 729 was 190 cmš / g. The molecular non-uniformity (fi w / Ün-1; was determined by gel chromatography to be 13, the proportion <MW / 5 to H9 f.: Xempcl_l2¿ Heath 10 mg of the catalyst prepared according to Example 16a. Example 18 b, however, with the addition of 127 mg of ethylaluminum dichloride instead of triisobutylaluminum and the addition of only 1.5 bar of hydrogen, the yield of polyethylene was 232 ß corresponding to 23.2 kg per gram of catalyst. The average grain size d 'was U8C1fmn. The viscosity number according to DIN 53 728 was 520 cmš / g. The molecular non-uniformity (ñw / Én-1) was determined gel-chromatographically to 5. , 5, manen Lñw / S to 30.8 fi.

Example 2_0_. a) Catalyst preparation. 9.1 g (52.7 mmol) of vanadyl (V) -chloride and 12.88 g (52.7 mmol) of vanadyl (V) -n-propylate were heated together in 89 ml of a hexane fraction 65/80 ° C under nitrogen for 2 hours under reflux. After cooling the mixture, a solution of 32.7 g (211 mmol) of isobutylaluminum dichloride in 11 ml of hexane fraction 63/8000 was added at 25 [deg.] C. within 2 hours with stirring with a blade stirrer and a specific stirring effect of H00 watts / month. The resulting suspension was then heated for a further 2 hours under reflux and stirred with the same specific stirring effect. After cooling, the solid was separated and washed 5 times with 500 ml each of the hexane fraction. b) Polymerization of ethylene.

In a two liter steel autoclave, 1 liter of a hexane fraction 63/8000 and 0.0 g of triisobutylaluminum were pre-charged under nitrogen.

To this was added 10 mg of the catalyst prepared according to Example 20a slurried in a few ml of the hexane fraction. After displacing nitrogen through ethylene, 1.6 bar of hydrogen was charged and then ethylene up to a total pressure of 31.1 bar. At the same time, the reactor contents were heated to 75 ° C. The polymerization was carried out for 1 hour with stirring at a stirring speed of 1,000 minutes * at 7500, the total pressure being maintained by reprinting ethylene. Then the reactor was released from pressure, the polyethylene formed was filtered off and dried after cooling the reactor contents.

The yield of polyethylene was 183 g, corresponding to 18.3 kg per catalyst. The average grain size d 'was 370 Fm, the bulk density according to DIN 53 H69 to 0, U25 g / ml, the flow rate VR lo to 9.2 cmš / sec. (DIN draft 53 H92). The molecular non-uniformity (fw / Én-1) was determined gel chromatographically to 25, the proportion <Üw / Still H5 ï. mol) of vanadyl (V) -chloride and 258 g (1.06 mol) of vanadyl (V) -n-propylate were stirred together in 1.77 l of a hexane fraction 63/8000 for 1 hour at room temperature. solution of 620 g (H mol) of isobutylaluminum dichloride in K, h5 liters of the hexane fraction 63/80 ° C was added synchronously within 2 hours to 2 liters of the hexane fraction at * P-360C with stirring with a mixed stirrer and a specific stirring effect of 78 The resulting suspension was then heated for a further 2 hours under reflux and stirred with the same specific stirring effect.After cooling, the solid was separated and washed 5 times with 5 liters each of the hexane fraction.b) Copolymerization of ethylene and butene- (1).

Then the vanadium catalyst described under 21 a is used with triisobutylaluminum as a cocatalyst for continuous polymerization of ethylene with the addition of small amounts of butene- (1). A 750 liter stirrer vessel was used as the polymerization reactor. The polymerization of the ethylene in mixture with butene- (1) took place in a suspension of a hexane fraction in the boiling range between 6300 and 80 ° C and powdered É polyethylene and catalyst. The filling level in the polymerization tank was 300 liters; as the average residence time of the catalyst in the polymerization vessel, 2 hours was chosen.

The copolymerization of ethylene and butene- (1) was carried out at a temperature of 75 ° C. In the gas space of the polymerization reactor, an ethylene partial pressure of 3H, 1 bar and a hydrogen partial pressure of 0.9 bar were maintained by continuous post-dosing of ethylene and hydrogen, which were used to control the average molecular weight. The comonomer, butene- (1) was provided in comparison with ethylene in a weight ratio of 2 to 100. Catalyst and san catalyst were diluted in a stirrer in hexane 63/80 ° C and then fed continuously with a metering pump to the polymerization tank. The concentration of the catalyst in the polymerization reactor was 3.53 mg / liter of suspending agent and of the cocatalyst 100 mg / liter of suspending agent. The speed of the agitator in the zeroing tank was 150 min._l. The copolymer formed in the reactor was separated in a centrifuge from suspending agent and dried in a partially evacuated container at about 8000.

The copolymer prepared in this way had the following properties: 7800161-7 20 Average molecular weight Fmëltinêex HFI 190 / E according to DIN 53 755 Viscosity number In accordance with DIN 53 728 Density at 23 ° C according to DIN 53 H79 Molecular non-uniformity U (U = Mw / Mn- 1) Molecular weight fraction 4 IWW / S Total ash Ash analysis 168,000 0, U6 g / 10 min. 380 cmš / g 0,956 g / cm fi 20,1 H6,6 š 50 PPN 50 ppm Al2O3 9 ppm V205 15 ppm chlorine The numerical consumption of catalyst in the above-mentioned driving mode was 37.1 mg V-ka * e 1 "satcr / kg polyethylene and 1,120 mg triisobutylaluminum / kg polyethylene The bulk density of the copolymer, determined in accordance with DIN 53 Ä68, was 0,1 H52 g / ml.

The sieve analysis gave an average grain size d 'of 550' m. When determining the flowability according to DIN draft 53 H92, the flow rate VR 10 was determined to be 8.2 cm 3 / sec.

Claims (4)

1. ___._.___.__..._____-__ * _.._. __ V. "* WYN- -f fl ß-Ww flfi ßf-'Hwwww fl- Iuww wrv-euanuwmuww-ww- ~~« - ~ -. _ -.-, - «__., PATENT REQUIREMENT Process for the production of powdered ethylene polymers with high bulk densities, good flowability , average grain diameters up to 1000 μm and practically free from dust particles by polymerization of ethylene, optionally in admixture with small amounts of propylene or butene-1 and in the presence of hydrogen, in inert liquid hydrocarbons at temperatures between 50 ° C and about 95 ° C and pressures of 10-100 bar, preferably 20-60 bar, by discontinuous or continuous process using Ziegler catalysts, prepared in inert liquid hydrocarbons by reaction of chlorine and alkoxy-containing vanadyl (V) compounds with organoaluminum compounds , senarization of the insoluble reaction product and activation with aluminum alkyl compounds, characterized in that 1. as vanadyl (V) compound a reaction product of vanadyl (V) chloride and a vanadyl (V) alcohol with 2-4 kolato- m in molar ratios of 1: 2 to 2: 1 or directly the reaction product of vanadyl (V) chloride with an alcohol having 2-4 carbon atoms, preferably ethanol, propanol- (1), butanol- (1) in molar ratios of 1 : 2 to 1: 1 and 2. as organoaluminum compounds for reduction use ethylaluminum dichloride and / or diethylaluminum chloride or isobutylaluminum dichloride and / or diisobutylaluminum chloride in molar ratios of aluminum-to-vanadium compound of 1: 1 to 3: 1, wherein 3. the reaction of the vanadium compounds with the aluminum-organic compounds is carried out with stirring with specific stirring effects of l-5000 watts / m3 And The activation takes place with aluminum alkyl compounds of the formula AlR3, wherein R are alkyl groups having 2 to 8 carbon atoms, or with alkylaluminum sesquichloride and / or alkylaluminum dichloride, in particular ethylaluminum sesquichloride and / or ethylaluminum dichloride. 7800161-7