DE3015376A1 - Alpha-olefin polymerisation catalyst prepn. - by modifying prim. solid contg. magnesium and halogen in two steps before activation - Google Patents

Abstract

Intermittent or continuous alpha-olefin polymerisation in gas- phase or in hydrocarbon dispersants, at 60-100 deg. C under pressures 2-40 bar, opt. using H2 as mol. wt. regulator, is catalysed by a solid contg. side-Gp. IV and/or V elements, Mg, halogen, oxygen, opt. a (further) main Gp. II and/or III element, and activated organometallic main Gp. II and/or III cpds. Novelty consists in preparing the catalyst, to be still activated in alpha-olefin polymerisation, by reacting a prim. solid contg. Mg and halogen in 2 consecutive steps (A) and (B). In (A), the solid Mg cpd. is reacted with sec. or tert. alcohols or their mixts. and with halogen-contg. cpds. of one or more side-Gp. IV and/or V metals. In (B), the (prim.) solid is reacted with halogen-contg. side-Gp. IV and/or V metal cpds. and with at least one organic cpd. of a main Gp. II and/or III metal. Step (A) and (B) sequence is opt.. The catalyst is used in ethylene polymerisation.

Description

Process for the polymerization of alpha-olefins

The polymerization of α-olefins, especially ethylene, with The help of catalyst solids, the elements of IV. And / or V. subgroup des Periodic table, magnesium, halogen, oxygen and optionally boron or aluminum and are activated with aluminum alkyls, in the gas phase or in hydrocarbons known as a diluent and dispersant ict.

Since the properties of the polyolefin produced in this way are very much dependent on Depending on the catalyst used, there are already various types of catalyst systems proposed for the polymerization of α-olefins.

Most of the previously known aluminum alkyl activated catalyst solids produce products with a narrow molecular weight distribution in the polymerization of α-olefins, d. h ,, the mean degree of polymerisation of one produced in one polymerisation batch Polyolefin blend is in a narrow range. This narrow molecular weight distribution of the polymer causes extrudates produced therefrom due to "melt fracture" have rough surfaces, so that these polymers are suitable for many uses, e.g. B. for the production of hollow bodies and films, are unsuitable.

The object was therefore to produce polyolefins with a broad molecular weight distribution to manufacture.

Of the few known catalyst systems that Pro.uRte with broad Provide molecular weight distribution, a large part is technically not usable, because the polymerisation product in its grain properties does not match those during polymerisation, Reconditioning and further processing is sufficient or because the molecular weight distribution is not yet broad enough for many areas of application is.

Another part of these catalyst systems does not have enough high catalyst activity, so that larger amounts have to be used get into the polymer, impairing its properties, in particular stability and therefore can be rendered harmless or removed by complex subsequent processes have to.

Another part of these known systems only then supplies products with broadly distributed molecular weights, if the polymerization in the presence of special, exactly to be adhered to activator mixtures, another, if the polymerization in Presence of additional auxiliaries, which are then removed from the polymerization medium must be removed.

Another part of such well-known systems differs for the large-scale Use out because the physical properties, such as rigidity, impact resistance and stress cracking resistance of the molded articles produced from the polymerization product for many purposes-are not sufficient.

Some catalysts also discolor the product. These undesirable Discoloration is mainly caused by catalyst residues, and moreover often impair the light stability of the product.

As an example of a previously known catalyst, reference is made to DE-OS 26 35 298 referenced. This catalog is made by cutting a mixture of magnesium halide, Alkoxyaluminum halide, a tetravalent and a trivalent titanium compound produced. During the polymerization, however, s.land plant occurs, the polymers themselves have poor powder rheology, low bulk density and high fines content.

The object of the invention was therefore to provide a polymerization process for to provide alpha-olefins that contain products with a broad molecular weight distribution, provides good physical properties, good processability and good purity.

This problem is solved by the subject matter of the main application P 29 27 221.7 and the subject matter of the associated additional application P 29 31 045.0, both a process for batch or continuous polymerization of alpha-olefins in the gas phase or in hydrocarbons as dispersants at pressures of 2 to 40 bar, preferably up to about 15 bar and temperatures of 60 to 100 ° C., optionally using hydrogen as a molecular weight regulator in the presence of a solid as a catalyst describe the elements of IV. and / or V. Subgroup (s) of the Periodic Table of the Elements, magnesium, halogen, Oxygen and optionally a (further) element of II. And / or III. Main group (s) of the periodic table and with organometallic compound (s) of II. and / or III.

Main group (s) of the periodic table is activated. This method is characterized in that the subsequent in the polymerization of alpha-olefins still to be activated catalyst by reacting a magnesium and halogen containing Primary solid produced in two successive reaction stages A and B. is, the solid based on magnesium compound (s) in the reaction stage A with tertiary alcohols and halogen-containing metal compound (s) one or more elements of the IV. And / or V. Subgroup (s) of Periodic table is treated and in reaction stage B with halogen-containing (s) Metal compound (s) of one or more elements of IV. And / or V.

Subgroup (s) and at least one organometallic compound of II. and / or III. Main group (s) of the periodic table is implemented.

It is not critical to success of the invention, in which order the reaction stages A and B are carried out.

It has now been found that according to a further embodiment of the Invention in reaction stage A instead of the tertiary alcohols also secondary alcohols or mixtures of secondary and tertiary alcohols can be used advantageously can.

Otherwise, all of the above-mentioned patent applications apply Criteria also for the present embodiment and all listed here Features are fully on the subjects of the two older applications P 29 27 221.7 and P 29 31 045.0 are applicable.

Under 11a compound containing an element11 is used here before stood that the said element is chemically bound in the said compound, under periodic table 2.S according to Mendeleev (cf.

Handbook of Chemistry and Physics, 55th edition, inside cover).

As alpha-olefins which polymerize according to the process according to the invention all alpha-olefins can be used that were previously at pressures from about 2 - 40 bar in Presence of solid catalysts des so-called "Ziegler types" could be polymerized. Ethylene is preferred, optionally in a mixture with up to 10 mol% of α-olefins with 3 to 6 carbon atoms can be used and copolymerized.

For the preparation of the used in the method according to the invention The catalyst is based on a primary solid that contains magnesium and halogen.

This primary solid can preferably be produced by Magnesium compound (s) soluble in hydrocarbons with chlorinated hydrocarbons and / or chlorinated hydrocarbon compound (s) each having 1 to 6 carbon atoms is reacted (are), of which at least one of at least two chlorine atoms directly tied wears.

Suitable magnesium compounds soluble in hydrocarbons will be used individually as a mixture, in particular organomagnesium compounds general formulas R¹MgR² and / or R¹MgOR², in which R¹ and R² are the same or different straight-chain or branched alkyl or aryl radicals having 2 to 20 carbon atoms.

Particularly preferred are R¹MgR² compounds, such as. B. n-Butylethylmagnesium. Di-n-butylmagnesium, n-butyl-isobutylmagnesium, n-butyl-sec-butylmagnesium, di-n-hexylmagnesium, Di-n-pentyl magnesium, di-n-octyl magnesium. Diphenyl magnesium or mixtures thereof Links.

These organomagnesium compounds are particularly preferred with saturated chlorinated hydrocarbons and / or chlorinated hydrocarbons implemented, such as carbon tetrachloride, 1,1,1-trichloroethane, 1,1,2-trichloroethane, 1,1,2,2- and 1,1,1,2-tetrachloroethane, pentachloroethane, hexachloroethane or mixtures of these connections. However, chloroform is particularly preferably used.

The magnesium compound (s) and the organic chlorine compound, e.g. B. particularly preferably chloroform, werder preferably in amounts of 0.5 to 10, particularly preferably 1 to 4, mol of chlorine compound per mol of magnesium compound, preferably at temperatures from -10 ° C. to +150 ° C., in particular from 20 to 80 ° C. implemented with stirring.

Here the reaction time is the degree of dilution of the weaktanten largely uncritical. The reaction can take a few minutes or a few hours be carried out, e.g. B. in 30 to 120 minutes. the degree of dilution can vary widely Limits can be varied, e.g. B. May the organic chlorine compound, like that especially preferred chloroform, in pure form or dissolved in hydrocarbons, is used will. The organomagnesium compound must, however, before the start of the reaction be homogeneously dissolved in hydrocarbons.

The reaction can be carried out in such a way that d the organic Chlorine compound is added to the dissolved magnesium compound with stirring or that both reactants are metered into the reaction vessel at the same time while stirring. However, the organic chlorine compounds defined above are preferred Kind, particularly preferably chlorine form, in pure form or homogeneously in hydrocarbon presented in dissolved form and the hydrocarbon solution of the organomagnesium compound (s) metered in with stirring, as on this track a for the method according to the invention particularly suitable catalyst solid can be produced.

The one containing chlorine and magnesium prepared in the manner described Primary solid can be used further directly or, however, preferably before the further Treatment to be washed several times with hydrocarbons.

the primary solid is then mixed with hydrocarbon (s), so that a suspension that can be stirred is produced. Concentration is not crucial However, because of the better handling and. the better further implementation be as concentrated as possible in the first reaction stage that follows.

The sequence of the two successive reaction stages A. and B is not critical to the success of the polymerization process of the invention. Thus, the primary solid produced in the manner described above can initially be subjected to reaction stage A and either after completion of this reaction directly or after an intermediate cleaning step in the reaction stage B continue to be implemented. Is preferred. However, the reverse order of the Reaction stages, preferably with the interposition of a cleaning step, that is, reaction stage B is carried out before reaction stage A.

The primary solid (or, in the preferred embodiment, the manufacture of the catalyst in the modified solid in reaction stage B) is in the Reaction stage A with secondary (s) and / or tertiary (s) alcohol (s), preferably of the general formulas R3R4R5CoH or R³R4HCOH and with halogen-containing (s) Metal compound (s) of one or more elements of subgroup IV and / or V. of the periodic table implemented.

Here it is possible to first use the metal compound (s) mentioned and then to dose the alcohol (s) to the (primary) solid or both components to dose at the same time as the magnesium-containing solid, however, is preferred first the suspension of the (primary) solid with the Treated alcohol (s) and then added the metal compound (s).

Of course, the suspension of the solid can also be added to the mentioned reactants are metered in, but this should preferably be one The reactant does not come together with the other reactant before it goes with the (primary) solid has been put together.

The alcohols are preferably reacted with the solid suspension at -20 to 150 ° C., particularly preferably at 0 to 100 ° C., in particular at 20 to 60 0C, that of the metal compound (s) with the solid suspension preferably at -20 to 150 ° C., particularly preferably at 0 to 150 ° C., in particular at 50 up to 100 ° C.

As far as the halogen-containing metal compounds of IV. And / or V. Subgroup (s) of the Periodic Table are liquid, they can be used as such are, preferably, and if they are not liquid, however, they are preferably Used as concentrated as possible dissolved in hydrocarbons.

The reaction times of this reaction stage A are not critical, they can range from a few minutes (e.g. 15 minutes) to several hours (e.g. 2 hours) be.

The secondary and / or tertiary alcohol is preferably in one Amount from 0.01 to 1, in particular 0.1 to 0.5 mol per mol (gram atom) of in the solid contained magnesium and the metal compound is preferably used in amounts of 1 up to 50, in particular 5 to 15 mol per mole of secondary and / or tertiary alcohol used. It is of course possible to deviate from these areas, however the activity of the catalyst is particularly influenced by the amount of alcohol, so it is not preferred, especially in the amount of alcohol of the foregoing preferred range.

Of the preferred alcohols of the general formulas R³R4HCOH or R³R4R5COH, where R3, R4 and R5 are identical or different straight-chain saturated ones Alkyl groups each having 1 to 6 carbon atoms or R3 and R4 together are one Mean alkylene group with 4 or 5 carbon atoms, are tertiary butanol and Isopropanol is particularly preferred. As another example of a saturated secondary Alcohol may be mentioned as cyclohexanol. Among the halogen-containing metal compounds of elements of the IV. and V subgroup (s) of the peroid system are preferred here understood the compounds of titanium, zirconium and vanadium (vanadium); of these, in turn, the titanium compounds are particularly preferred.

In particular, in reaction stage A, the catalyst preparation the compounds of the general formula Xa Ti (OR6) 4-a and in the later in detail described reaction stage S of the catalyst preparation the compounds of the general Formula X'b Ti (OR7) 4-b proved suitable. In these formulas, X and mean: independently of one another in each case halogen, particularly preferably in each case chlorine, R6 and R7, independently of one another, are in each case identical or different straight-chain or branched ones Alkyl and / or aryl radicals with 1 to 8 carbon atoms and and b are independent of one another each 2, 3 or 4, preferably 4. The compounds can each be pure or as Mixtures are used.

Titanium tetrachloride is particularly preferred in each case.

If reaction stage A is used as the first reaction stage in the preparation of the catalyst for the process according to the invention carried out so is the so modified solids now preferably at 0 to 100 0C, in particular 20 to 100 ° C by repeated washing with hydrocarbons, sedimentation and decanting largely freed from soluble metal, especially titanium, compounds. These Washing processes are particularly preferred when those used in reaction stage A. Alcohols also contained primary alcohols. Preferably he will then again, like the primary solid before the first reaction stage, in hydrocarbons suspended.

What has already been said there applies to the concentration. The same procedure is followed when the reaction stage described below B is carried out as the first reaction stage of the catalyst preparation.

The solid modified in reaction stage A or in the preferred one Procedure in which reaction stage A is carried out after reaction stage B, the primary solid is at reaction stage 5 with at least one halogen containing Connection of at least one element of IV. And / or V. subsidiary group (s) of the periodic table, as it has already been defined above, and with at least one Organometallic compound from TI. and / or III. Main group (s) of the periodic table implemented.

The reaction is preferably at -40 to + 1C0 OC, especially at -5 to +70 ° C carried out, preferably per mole of solid-bound magnesium 0.01 to 5, in particular 0.1 to 1, mol of said metal compounds of the subgroup elements, in particular titanium tetrachloride, and per mole of said metal compound of the Nebergruppe elements, preferably 0.3 to 5, in particular 0.5 to 2.5 mol of the organometallic compounds mentioned of the main group elements used.

One mole of a substance mixture is that amount of substance understood the theoretically (conversion = 100% of theory) with the same amount of one Reaction partner reacts per 1 mole of a pure substance in this substance mixture is included.

Among the elements of II. And III. Main groups of the periodic table 3 beryllium, magnesium, boron and aluminum are understood here, by way of example the magnesium and particularly preferably the aluminum.

Among the organometallic compounds of these elements are understood that the metal atoms on alkyl and / or aryl radicals with 1 to 20 Contain carbon atoms bonded. Not bound by these mentioned residues Valences of the metals can also be with hydrogen and / or halogen, preferably Chlorine, also with alkoxy, aryloxy and / or siloxy radicals, each with 1 to 20 carbon atoms are saturated. Furthermore, oligomeric alkyl aluminum compounds are used, d. H. those compounds in addition to those mentioned above Substituents also contain aluminum-oxygen-aluminum bonds. Preferred compounds of the sintered formula AlRz8Y3-z are described in more detail here as examples for preferred compounds of this type are mentioned: aluminum triethyl, aluminum tri-n-butyl, Aluminum tri-isobutyl, aluminum tri-n-octyl, aluminum-isoprenyl, diethyaluminum hydride, Diisobutyl aluminum hydride, ethyl aluminum dichloride, diethyl aluminum chloride, ethyl aluminum sesquichloride, Diethylethoxyaluminum, ethyldimethylsiloxyaluminum diethyl, bis (di-isopropylaluminum) oxide and their mixtures.

In reaction stage B described above, diethylaluminum chloride, Ethyl aluminum sesquichloride, aluminum isoprenyl, aluminum tri-n-octyl or mixtures of these compounds are particularly preferred.

The reaction time of reaction stage B can be a few minutes (e.g. B. 15 minutes) to several hours (z. B. 2 hours), it is not critical.

The reaction stage B can be carried out so that initially the Main group compounds preferably dissolved in hydrocarbons, e.g. B. such of the aforementioned aluminum precursors, and preferably in hydrocarbons suspended primary solid or solid modified in stage A combined and according to the subgroup compounds, which are also preferably dissolved in hydrocarbons, z. B. the particularly preferred titanium tetrachloride are added. Also a simultaneous one It is possible to meter in the components. However, it is preferable to place the subgroup connection z. B. the preferred titanium tetrachloride, and the Fentstoff, both preferably in Hydrocarbons dissolved or suspended, before and. doses the main group compounds, preferably the aluminum organyl compounds.

Preferably, the catalyst solid is the modification in the both reaction stages A and 9 at 0 to 100 0C by repeated washing with hydrocarbons, Sedimentation and decanting largely freed from soluble compounds.

It can also be advantageous, especially with regard to the reaction stage B is carried out before reaction stage A, ie this is particularly preferred To subject the catalyst solid to an aftertreatment after the 2nd reaction stage.

This aftertreatment is carried out by converting a stirrable suspension of the catalyst solid in hydrocarbons with one or more, preferably Organometallic compound (s) of II. and / or. likewise dissolved in hydrocarbons III.

Main group (s) of the periodic table, as already defined above are. Of the preferred organoaluminum compounds, in particular Diethyl aluminum chloride, ethyl aluminum sesquichloride, aluminum soprenyl, aluminum tri-n-octyl and mixtures thereof are preferred.

This additional aftertreatment of the catalyst solids is preferred at temperatures from -40 ° C to 150 ° C, in particular from -20 ° C to 100 ° C below Use of preferably 0.01 to 5, in particular 0.1 to 1, mol of the organometallic compound (s) carried out per mole of magnesium bound in the solid.

What was said at the beginning about the concentration of the solid suspension applies to all stages of catalyst preparation.

The reaction time of the aftertreatment can also be a few minutes to several hours (e.g. 15 minutes to 2 hours).

Another advantageous option for follow-up treatment, be it that reaction stage Q was carried out before or after reaction stage 5, exists therein, the solid in suspension for several hours * at temperatures of 50 to 100 ° C to age and then wash off. * (e.g. 2 to 8 hours) The preparation of the catalyst solid and the inventive implementation of the polymerization must be excluded also carried out small amounts of oxygen and of water or water vapor will.

The catalyst solid prepared in the manner described above, who preferably by. Washing at preferably 0 to 100 0C with carbon dioxide, Sedimentation and decanting, in particular freed from soluble metal compounds is suitable for use in the polymerization of those according to the invention alpha-olefins, which were previously in the presence of catalysts of the "Ziegler type" polymerized at pressures of about 2 to 40 bar in the gas phase or in dispersion could earth. tn one more preferred. Embodiment of the method according to the invention ethylene is mixed with 0 to 10 mol% alpha-olefins with 3 to 6 carbon atoms, z. B. propene, butene-1, isobutene, pentene-1, Hc = cen-1, used and (co) polymerized.

Particularly good results are obtained when ethylene is homopolymerized.

The inventive, with the catalyst system described above initiated polymerization can be carried out in the gas phase or in suspension. In the preferred polymerization in suspension, the reactants, preferably dispersed in a hydrocarbon or a hydrocarbon mixture and pressures of 2 to 40 bar (absolute), preferably 2 to 11 bar and temperatures polymerized from 60 to 100 ° C. This can optionally be done by adding hydrogen the chain length of the resulting polymers, or, in other words, the degree of polymerization of the products are regulated.

In the context of this application, hydrocarbons are compounds understood, which are composed of the elements carbon and hydrogen, Saturated compounds such as straight-chain, branched and cyclic compounds are preferred Alkanes or paraffinic hydrocarbons, which at the specified temperatures and Pressures are predominantly liquid, e.g. B. Alkanes having 3 to 20 carbon atoms. Examples are propane, butanes, pentanes, hexanes, heptanes, octanes, the nonanes, the decanes, decalin, cyclohexane and their mixtures.

To initiate the polymerization, the catalyst solid is through Addition of netallorganyl compound (s) of II. And / or III. Main group (s) of Periodic table activated to the polymerization mixture.

Of the compounds of this type already defined above organoaluminum compounds of the general formula 8 8 AlR Y or mixtures preferred thereof in which R is identical or different straight-chain or branched Alkyl and / or aromatic radicals with 1 to 20 carbon atoms, hydrogen and / or identical or different halogen atoms, Alkox.y-, aryloxy- and / or Siloxy radicals each having 1 to 20 carbon atoms and z is 2 or 3. Particularly aluminum triisobutyl, aluminum tri-n-octyl and aluminum isoprenyl are preferred as well as their mixtures.

Also those already described in the description of reaction stage B. Oligomeric aluminum organyl bonds can be used here.

The organometallic compounds of II. And III. Main groups of the periodic table are preferred over the subgroup elements bound in the catalyst solid the IV and V main groups used in excess. It is of course also possible to use a deficit or stoichiometric amounts. In a preferred Embodiment are z. B. 2 to 10O, in particular 5 to 50 mol of aluminum compound (s) per mole contained in the catalyst solids, where chemically bound titanium is used.

The polymerization process of the present invention can be continuous or carried out batchwise. With the discontinuous procedure are prepared in the manner described above catalyst solids, Activator, alpha-olefin, optionally hydrocarbon and optionally hydrogen placed in the reactor, preferably an autoclave, and then the polymerization carried out. Of course, some or all of the components can be used in whole or in part can be added subsequently.

In the continuous procedure, the reaction components mentioned are separately or as a mixture in the desired composition in the reactor continuously fed in.

Here, too, subsequent dosing of partial quantities is a matter for an individual or all components possible, when using z. B. of tubular reactors also at different Place the reactor.

The process according to the invention can produce polymers that do not need to be subjected to any further post-treatment. This is achieved due to the small amount of dea required because of its surprisingly high activity Catalyst system that do not noticeably adversely affect the product can.

Another advantage of the catalyst system is the production of Polymers with excellent powder properties, broad molecular weight distribution, very good physical properties and good processability. For example know the polymers produced according to the invention by blow extrusion "free of melt fractures", z. B. to form hollow bodies or foils. From the very good physical ones The only properties here are the high rigidity. high impact strength and called the good stress cracking resistance.

The invention is illustrated below by way of examples and comparative examples further discussed.

The MFI5 melt binder mentioned in the examples is produced in accordance with DIN (German Industry standard) 53 735 determined at 190 ° C and 49.03 N (5 kp) load.

The flow factor F21.6 is the quotient of the melt indices at 211.82 N (2z, 5 kp) and 49.03 N (5 kp) load and can be used as a measure of the molecular weight distribution are valid.

The catalyst which can be used in the polymerization according to the invention can e.g. B. be produced in the following way: a) Manufacturing of the primary solid 900 ml of a hexane-heptane solution containing 0.5 mol of n-butyl-sec-butylmagnesium contained, within 2 hours at 60 ° C to 1 mol of chloroform in 420 ml isooctane dosed. A brown solid formed. It was stirred for approx. one hour at 60 ° C and then washed the solid at 50 to 60 0C 3 times with 3 liters of isooctane each time by repeated sedimentation and decanting. It was then made up to 1 liter.

b) Preparation of the catalyst solid bl) 100 ml of the prepared according to a) Primary solid suspension containing 50 mmol of magnesium were presented and 20 mmol of isopropanol are added at room temperature with stirring. After an hour 100 mmol of TiCl4 were added to the suspension while stirring at 50.degree. C. and the mixture was heated to 90.degree and stirred at 90 ° C. for a further 2 hours. It was then cooled to 50 ° C. and the solid by repeated sedimentation and decanting for so long with isooctane washed until practically no more dissolved titanium can be detected in the dispersant was.

18.8 mmol of titanium were fixed on the solid.

The solid was suspended in 70 ml of isooctane and kept at room temperature mixed with 15 mmol Diol4. Then 30 was added with stirring mmol of ethyl aluminum sesquichloride, dissolved in 15 ml of isooctane, within a few minutes. After heating to 50.degree. C., the mixture was stirred at 50.degree. C. for 1 hour and then under repeated sedimentation and decanting at 50 0C washed with isooctane until Practically no more soluble chloride or aluminum can be detected in the dispersant was.

A total of 33.2 mmol of titanium was fixed on the catalyst solid.

b2) 100 ml of the primary solid suspension prepared according to a), the Containing 50 mmol of magnesium, were submitted and stirred at room temperature mixed with 15 mmol of titanium tetrachloride. Then 30 mmol ethyl aluminum sesquichloride, dissolved in 15 ml of isooctane metered into the suspension within 1/4 hour. After this Warming to 50 ° C., the mixture was stirred for a further 11/2 hours. and at this temperature like that Washed with isooctane for a long time until practically none in the decanted liquid aluminum and no more chloride could be detected.

The solid contained 14.5 mmol of bound titanium.

After being taken up in 100 ml of isooctane were taken at room temperature Stirring 15 mmol of isopropanol, dissolved in 10 ml of isooctane, metered in. The suspension was then stirred at 50 ° C. for 1 hour. After adding 100 mmol of titanium tetrachloride warmed to 90 0C and stirred for a further 1/2 hour. After cooling to 50 0C took place another washing process until there is practically no dissolved isooctane in the decanted isooctane Titan was more detectable.

It was found to be expedient to re-dissolve the solid in 300 ml of isooctane and age for 3 hours at 90 ° C. After repeated washing at At 50 ° C. with isooctane, the catalyst solid contained a total of 21 mmol of bound Titanium.

b3) 100 ml of the primary solid suspension prepared according to a), the 50 mmol of magnesium were placed and stirred at room temperature mixed with 20 mmol titanium tetrachloride. Then 30 mmol ethyl aluminum sesquichloride, dissolved in 15 ml of isooctane metered into the suspension within 1/4 hour. After this Heating to 50 ° C. was stirred for a further 1 1/2 hours and at this temperature like that Washed with isooctane for a long time until practically none in the decanted liquid Aluminum and no more chloride were detectable.

The solid contained 18.3 mmol of bound titanium.

After being taken up in 100 ml of isooctane were taken at room temperature Stirring 15 mmol of isopropanol, dissolved in 10 ml of isooctane, metered in. The suspension was then stirred at 50 ° C. for 1 hour. After adding 100 mmol of titanium tetrachloride became heated to 90 ° C and stirred for a further 1 hour. After cooling to 50 ° C., a Another washing process until there is practically no dissolved titanium in the decanted isooctane was more detectable.

The further treatment took place as in example 1). The catalyst solid contained a total of 25.5 mmol of bound titanium.

c) Production of catalyst solids not according to the invention cl) b1) was repeated, except that n-propanol was used instead of isopropanol.

The catalyst solid contained a total of 15.9 mmol bound Titanium.

c2) b3) was repeated, except that n-propanol was used instead of isopropanol used.

The catalyst solid contained a total of 19.6 mmol bound Titanium.

Examples 1 to 10 and Comparative Experiments A to C The polymerization was in a 5-liter laboratory autoclave in 3500 ml isooctane with stirring for 650 min 1 and 10 bar total pressure carried out.

Table 1 summarizes the experiments with the results of the polymerization.

While the products of Examples 1 to 10 are "free from melt fractures" allowed to extrude, the extrudates of comparative tests A to C showed average to severe melt fracture.

Table 1 Examples of catalyst mgTi 2 ml AlR3 and Ver produced 1) immediately after experiments 1 b1) 16.2 Al-isoprenyl 2 "18.9" 3 b2) 15.3 4 "13.6 "5" 10.3 "6" 15.3 Al (n-C8H17) 3 7 b3) 15.6 Al-isoprenyl 8 "15.6" 9 "17.5" 10 "17.8 Al (n-C8H17) 3 A cl) 10.1 Al-isoprenyl B c2) 15.5 C" 18.5 " Tabel 1 Examples Vol.% ° C Time in gPE and H @ in hours 2) same gas space attempts 1 16 90 1 3/4 1240 2 25 "" 1150 3 27 "1 1/2 1240 4 24 II II 1265 5 17" "1135 6 32 "" 1080 7 24 "" 1140 8 27 "1 3/4 1260 9 36" 2 1200 10 31 "1 1/2 1143 A 21 "" 1180 B 24 "" 1200 C 30 "" 1160 Table 1 Examples of MFI5 / F21.6 MFI5 / 21.6 bulk density fine fraction and comparative (powder) (granulate) g / l 4100 pm in% attempts 1 0.25 / 17.2 0.19 / 20.5 440 0.0 2 1.1 / 17.4 1.0 / 18.9 465 0.3 3 0.59 / 18 0.48 / 20.8 400 0.1 4 0.41 / 17.6 0.35 / 20.0 400 0.1 5 0.14 / 17.9 0.10 / 23.3 370 0.1 6 0.99 / 16.9 0.83 / 18.7 395 0.0 7 0.22 / 20.5 0.19 / 21.6 410 0.3 8 0.38 / 20 0.36 / 21.4 425 0.1 9 1.00 / 19.6 0.93 / 20.4 430 0.3 10 0.51 / 20.6 0.51 / 21.8 430 0.3 A 0.8 / 14.1 L 385 0.2 B 0.43 / 16.4 0.36 / 16.7 420 0.1 C 1.10 / 16.7 0.93 / 17.0 415 5 0.0 1) bound on the catalyst solid 2) polyethylene

Claims (1)

Claim method for discontinuous or continuous Polymerization of alpha-olefins in the gas phase or in hydrocarbons as Dispersant at pressures from 2 to 40 bar and temperatures from 60 to 100 0C, optionally using hydrogen as a molecular weight regulator in the presence of a solid as a catalyst according to the patents ... (Patent applications P 29 27 221.7 and P 29 31 045.0), d a -d u r c h e k e n n n n e i c h n e t that in the preparation of the catalyst solid instead of the tertiary alcohols, secondary alcohols or mixtures of secondary and tertiary alcohols are used.