DE2831581A1 - CARRIER CATALYST FOR THE POLYMERIZATION OF L-ALKYLENE, IN PARTICULAR OF AETHYLENE - Google Patents

Description

Dr. F. Zumstein Sr. - Dr. E. Ass <r> anr. - D: \ R. Koenigsberger Diploma Phys. R. Holzbauer - Dipl .-! Ng. F. Klingseisen - Dr. F. Zumstein jun.

PATENT LAWYERS

80OO Munich 2 - Bräuhausstrasse 4 -Telephone collective no. 2253 41 Telegrams Zumpat - Telex 529979

Mark; 2908 PT

STAMICARBOU B.V., Geleen / Netherlands

Supported catalyst for the polymerization of 1-alkylenes , especially ethylene

The present invention relates to a process for the polymerization of a 1-alkylene having 2 to 8 carbon atoms, optionally with minor amounts of a maximum of 10 mol% of one or more other 1-alkylenes with 2 to 8 carbon atoms, preferably ethylene with a maximum of 2 if desired Mol .-% propylene and / or butylene, in the presence of a catalyst which is produced by reaction of a chromium-1,3-diketo compound of the formula Cr (OCR CR CR 0),

1 2 * * j ό

in which R ,, R_ and R "have the same or different meanings and each represent an alkyl group having 1-10 carbon atoms, while R can also represent a hydrogen atom with an organometallic compound a metal of group II or III of the periodic table, in which hydrocarbyl groups with 1-20 carbon atoms over one carbon atom are bound to the metal in question, bringing this reaction product together with an inert inorganic carrier, heating the reaction product of the chromium compound deposited on the support

ο in a non-reducing environment to a temperature between 200 and 1200 C. and then mixing the product obtained in this way with "an organometallic compound of a Group II or III element of the Periodic table is obtained. Such a method is described in DE-OS 27 23 416.

803885/0963

The chromium compounds of the above formula are chromium complexes of 1,3-diketo compounds of the general formula:

R ₁ - C - C - C - R_
¹ 11! ! I ³
0 HO

in which R, R and R have the aforementioned meaning, such as acetylacetone,

1 Ct O

Hexane-2,4-dione, heptane-2,4-dione, octane-2,4-dione, octane-3,5-dione and Homologues of the compounds mentioned in which R instead of a hydrogen atom is an alkyl group having 1 to 20 carbon atoms. Preferably the Diketover compound acetylacetone and the chromium compound derived from it the chromium (III) acetylacetonate.

Such a chromium-1, 3-diketo compound, preferably chromium (III) acetylacetonate, is combined with an organometallic compound of a metal from group II or III of the periodic table, such as beryllium, magnesium, borium, Aluminum or gallium. The hydrocarbyl groups in these Compounds are preferably alkyl groups with 1-20 carbon atoms.

Suitable organometallic compounds are, in particular, aluminum trialkyls and magnesium dialkyls. The alkyl groups of the magnesium dialkyls contain preferably 4-12 carbon atoms and especially 4 to 8 carbon atoms. Suitable organomagnesite compounds are diethylmagnesium, dipropylmagnesium, Diisopropylmagnesium, dibutyl- or diisobutylmagnesium, diamylmagnesium, dihexylmagnesium, dioctylmagnesium, didecylmagnesium, Didodecylmagnesium, but also dicycloalkylmagnesium with the same or various cycloalkyl groups with 3-12 carbon atoms and preferably with 5 or 6 carbon atoms. An alkyl or a cycloalkyl group attached to magnesium. Although alkyl and cycloalkyl magnesium compounds are preferred, so can Magnesium aryls are used, especially diphenylmagnesium, but also ditolyl and dixylyl magnesium. The diaryl magnesium compounds are insoluble or poorly soluble in aliphatic hydrocarbons and are therefore dissolved in aromatic hydrocarbons. The organomagnesium compounds can be prepared in a manner known per se (see e.g., G.E. Coates, M.L.H. Green, and K. Wade; Organometallic Compounds, Vol. 1, and F. Runge: Organometallverbindungen). In particular one uses solutions of magnesium alkyls according to that in the Dutch The method described in U.S. Patent 139,981.

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Suitable aluminum compounds are aluminum trialkyls and organoaluminum compounds of the general formula (R) J ^ LX, in which R represents an alkyl group having 1-10 carbon atoms and X denotes hydrogen or a halogen. For example, those from the German Auslegeschriften 1.956.353, 1.183.084, 1.136.113 and 1.186.633 known aluminum compounds, with one or more derived from a diene therein Leftovers, are used.

The implementation of the chromium diketo compound, preferably the ChromiumCllDacetylacetonate, with an organomagnesium or organoaluminum compound must be carried out in a solvent which is inert towards these compounds. The conversion of the chromium compound is preferably carried out with the organometallic compound in a hydrocarbon solvent, in particular in one or more aliphatic hydrocarbons, such as hexane, heptane, or in one mainly composed of hexanes and / or Heptanes existing mineral spirits. Also lighter hydrocarbons, such as butanes and pentanes, and heavier hydrocarbons, in particular Petroleum fractions such as gasoline, kerosene and gas oil are useful. Everything else suitable solvents such as halogenated hydrocarbons can also be used as the reaction medium.

The chromium-ljS-diketo compounds and in particular the chromium (III) acetylacetonate are more soluble in aromatic hydrocarbons than in aliphatic hydrocarbons, and they can be easily mixed with Magnesium diarylene which is soluble in aromatic hydrocarbons react permit. Because of the cost price of aromatic hydrocarbon solvents and especially because of their toxicity, they are generally preferred not to be used when in adequate embodiments of the process in aliphatic and / or cycloaliphatic solvents are applicable. Chromium (III) acetylacetonet is in aliphatic and / or Cycloaliphatic hydrocarbons are sparingly soluble and become in them be partially dispersed. If an organomagnesium or organoaluminum compound is added, the chromium-III-acetylacetonate goes probably with simultaneous formation of a complex connection, with the organomagnesium or organoaluminum compound, at least partially in Solution. This process is carried out by gently heating to e.g. 40 to 100 ° C or at lower boiling solvents by heating to the boiling point of the Solvent accelerated. Chrcm (III) acetylacetonate in light petrol colors this petrol light purple because a small amount goes into solution. With the Organomagnesium or organoaluminum compound gives the solution a

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dark colour. In these solutions the atomic ratio Mg: Cr or Al: Cr is 0.5: 1 to 10: 1 and in particular 1: 1 to 3: 1. Such a solution is brought into contact with an inert inorganic carrier, by adding the solution, for example, slowly and with constant stirring to a carrier suspended in the solvent.

The chromium compound can settle on the carrier through evaporation, insofar as it has not already been completely or partially deposited on the carrier from the solution. When the chromium compound is out of solution settles on the carrier, this is clearly visible because the solution is completely or largely decolorized and the carrier takes on color.

However, it has been found that the properties of the Polyalkylene powder, especially polyethylene powder, is often desirable leave behind, causing problems in processing. When passing through a funnel-shaped bunker or filling funnel, e.g. for extrusion, or for bulk loading, i.e. When loading bulk goods (= product that has not sagged), bridging often occurs on what is extremely annoying. It also shows that the polyalkylene a lot fine material, i.e. contains particles less than 70μ, which Can cause dust problems, which are extremely unpleasant, especially when loading and transporting bulk goods. The content of fine Material is sometimes 10% by weight and more.

It has now been found that polyalkylene powder with good powder properties can be produced by using a 1-alkylene with 2 to 8 carbon atoms, possibly with minor amounts of a maximum of 10 mol% of one or more other 1-alkylenes with 2 to 8 carbon atoms , preferably ethylene with possibly small amounts of a maximum of 2 mol% propylene and / or butylene polymerizes in the presence of a catalyst which is produced by reaction of a chromium-1,3-diketo compound of the formula CR (OCR ₁ CR CR "O) _, in which R ₁ , R ₀ and R are the same or

XaOO Xa O

have different meanings and each represent an alkyl group with 1-10 carbon atoms, while R _{2 can} also denote a hydrogen atom, with an organometallic compound of a metal of group II or III of the periodic table, in the hydrocarbyl groups with 1-20 carbon atoms via a carbon atom on the relevant Metal are bound, this reaction product is brought into contact with an inert inorganic support, and the reaction product of the chromium compound deposited on the support is not heated

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reducing environment to a temperature between 200 and 1200 C and subsequent mixing of the product obtained in this way with an organometallic compound of an element of group II or III of the periodic table is obtained - and this characterizes the present invention - as a carrier silicon dioxide with a medium Particle size of at least 40 μ and a uniformity coefficient of at least 2 are used.

The processing properties of polyalkylene powders, which under Application of catalysts produced according to Dutch patent application 76.05535 often leave something to be desired even if the quantities of fine material were relatively small. Applicant has found that the particle size distribution plays an important role. The uniformity coefficient, often referred to as η, must be at least 2. The determination of the particle size and the Particle size distribution is well known and is carried out by means of sieve analysis. The results of the sieve analysis can be graphed being represented. After Rosin and Rammler (Kolloid Zeitschrift j37 (1934) pp. 16-26, and Chem. Ing. Techn. 24 (1942) pp. 25-31) can the Particle size distribution by the equation:

e Φ

loo - ^{θ x}

are shown, in which R is the weight fraction in% that on a sieve with a mesh size χ remains, and χ represents the mean particle size. Taking the logarithm twice changes above equation in (log -—) = η log χ - η log χ + log (log e), a

Equation which, when entered in a double logarithmic-logarithmic Rosin-Rammler-Netz is represented by a straight line.

For x = x, - - = e or R = 36.8%, ie the mesh size of a sieve, R

on which 36.8% lag behind while 63.2% step through denotes the mean particle size. Of course, in general, no mesh size of a standard sieve will exactly match this value, but the The mean particle size is read off from a Rosin-Rammler diagram on the line for which R = 36.8.

The parameter n, the uniformity coefficient, is a measure for the width of the particle size distribution. The larger n, the narrower the particle size distribution.

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Applicant has now observed that for the production of a polyalkylene with favorable powder properties, ie with less fine material with a particle size of less than 70 β and a narrow particle size distribution with η = at least 2, the support for the catalysts in question also meets the above requirements with regard to the particle size and the particle size distribution must be sufficient. Another advantage is that the carrier with the catalyst component deposited thereon can be calcined very well in a non-reducing atmosphere by fluidizing the carrier in a hot air stream. In the case of very fine carriers, this cannot be carried out and other possibilities must be used in which the supply of the non-reducing gas to the carrier particles is less good and the possibility cannot be excluded that reducing conditions arise in some places.

Very active catalysts are obtained with silica supports, - "■ -" 3

their pore volume at least 1.5 cm / g and their sodium content at most 200 ppm and is preferably at most 150 ppm. It turns out that it is beneficial to dry the support, e.g. by heating it in dry air, before the complex chromium compound is allowed to precipitate on it. The drying must be carried out in such a way that the carrier preferably does not have any contains more physically bound water.

The amount of the complex chromium compound described above that is on attached to a carrier can vary within wide limits, but is generally from 0.01 to 10% by weight, calculated as chromium on the carrier. Larger and smaller quantities are possible, but do not offer any Advantages. It is preferable to apply enough complex chromium compound to the support that the chromium content is 0.02 to 2% by weight and in particular 0.05 to 1% by weight % By weight.

Having the complex chromium compound in a dispersant with the carrier is brought together, the carrier and the chromium compound become by evaporation or filtering off the dispersant separately. If the chromium compound does not settle to a significant extent on the carrier, what does it do? manifested by missing or slight discoloration of the dispersant, one will evaporate the dispersant. The carrier with the precipitated chromium compound is then placed in a non-reducing atmosphere, such as oxygen, air, nitrogen, carbon dioxide or a noble gas, to one

ο
Heated temperature from 200 to 1200 C.

The atmosphere in which heating is carried out is preferably oxidizing (e.g. Oxygen or air), whereby of course air with reduced

809885/0963

or increased oxygen content creates an oxidizing atmosphere. The carrier with the chromium compound is preferably heated to 400 to 1200.degree

ο
and in particular heated to 500 to 1100 C. The heating time can range from a few seconds to several tens of hours

ο and longer can be varied. At temperatures between 500 and 1100 C. the heating time can generally be from 30 minutes to 6 hours. The person skilled in the art can determine the optimal heating time experimentally can easily be determined by producing catalysts of the same composition under otherwise constant conditions The heating time at a certain heating temperature varies and the properties of the catalysts obtained in this way are determined.

Preferably, the support with catalyst component is after Cool to ambient temperature in a hydrocarbon solvent given, which is preferably the polymerization medium. These can be aliphatic or cyclic hydrocarbons, such as butane, isobutane, normal or branched pentenes, hexanes, heptanes, octanes, etc., cyclopentane, cyclohexane, cycloheptane, cyclooctane, etc. and mixtures, especially those Fractions obtained directly or indirectly from crude oil, such as light petrol, gasoline, kerosene or gas oil, which may contain aromatics, but consist predominantly of aliphatics and / or cycloaliphatics. For technical reasons, aromatic hydrocarbons such as benzene, Toluene, xylenes, and halogenated hydrocarbons are useful for practical reasons, namely in connection with the cost price and toxicity, one becomes aliphatic or hydrocarbons Prefer petroleum fractions in general. The chrome component-on-carrier, which is dispersed in an inert dispersant is an organometallic compound of an element of group II or III of the Added to the periodic table, such as beryllium, magnesium, borium, aluminum or gallium. The molar ratio between the organometallic compound and the on Chromium component attached to the carrier can be used within wide limits, e.g. between 0.1: 1 and 200: 1. Preferably this is Ratio between 5: 1 and 40: 1. The polymerization of 1-alkylenes with inventive catalysts is preferably carried out in an inert dispersant under such conditions that a Suspension of the polymer in the dispersant is obtained. In the case of the polymerization of ethylene, this means that the polymerization temperature

ο ο

generally below 110 ° C., preferably below 100 ° C. and especially not

above 90 ° C is selected. In very volatile solvents it is

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Suspension polymerization is still possible at 110 C and even at higher temperatures. The polymerization can, however, also at higher Temperatures of e.g. 150-200 C are carried out, in general a solution of polyethylene in the dispersant accumulates on can be processed in a known manner. The polymerization can also be carried out as a so-called gas phase polymerization, of which Polymerization from British patent 1,373,982, among others Embodiments are known. The polymerization of propylene and higher olefins can also be carried out in liquid monomer.

In order to achieve a good rate of polymerization, one will polymerize generally at an elevated temperature, e.g. 50 ° C or higher, and preferably at temperatures of 70 ° C minimum. the Polymerization can be carried out under atmospheric pressure, however even under increased pressure, which is when using low boiling points Dispersants such as butane, isobutane or pentane will be required. If the polymerization is carried out under increased pressure, you can higher yields can be achieved, so that one can generally at

2
increased pressure up to eg 100 kg / cm will work. Higher pressures, up to

E.g. even 2000 kg / cm and more are possible, but will work out generally not used for practical reasons. Preferably

2 is polymerized at pressures between 6 and 80 kg / cm and in particular

2
between 12 and 50 kg / cm. The amount of catalyst is generally chosen so that there is 0.001 to 10 mmol and preferably 0.01 to 1.0 mmol of chromium per liter of dispersant in the dispersant. The suspensions or solutions obtained during the polymerization in a solvent can be worked up in a manner known per se. Modifications known per se can be made in the process according to the invention. For example, the molecular weight can be regulated by adding hydrogen or other customary modifying agents. The polymerization can also be carried out in two or more stages connected in parallel or in series, in which, if desired, different catalyst mixtures, temperatures, residence times, pressures, hydrogen concentrations, etc. can be used. Products with a broad molecular weight distribution can be prepared, for example, by choosing the conditions in one stage so that a polymer having a high molecular weight is obtained, while in another stage these conditions are chosen so that a polymer having a relatively low molecular weight is obtained.

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The present invention will be illustrated by the following examples explained in more detail without being limited to it.

Comparative example A.

In a 1 liter flask operated with a stirrer, is provided with a reflux condenser and a feed, 2 g of chromium (III) acetylacetonate (5.75 mmol) in 500 ml of dry mineral spirits (boiling range, 65-85 c) suspended. This suspension is heated with constant stirring, until the gasoline boils, after which 2.2 ml of a 3.91 molar solution (8.61 mmol) of triisobutylaluminum (TIBA) are added dropwise. It educates now a dark brown-green solution that only contains traces of solids. After filtration, 210 ml of the solution obtained in this way are obtained added dropwise to a suspension of 60 g Aerosil 200 V in 900 ml dry gasoline. The Aerosil 200 V is pre-dried, i.e. 16 hours on

120 C has been heated.

Aerosil 200 V is a silica gel marketed by Degussa with an average particle size of 6 β and a uniformity coefficient η = 1.5.

After a short time, the dark colored solution has become discolored and the silica gel carrier material has taken on color. The silica gel carrier with the chromium compound deposited on it is now by evaporation of the light gasoline is separated from the dispersant, after which the powder obtained in this way is dried for 16 hours at 50 ° C. under vacuum. The powder is then heated to 900 ° C. in a rotary kiln under a stream of dry air. The warm-up time is about 1 hour, and that Powder is held at 900 ° C. for one hour. After cooling, the catalyst powder is suspended in so much gasoline that the concentration 5 g of catalyst-on-trap per 100 ml of gasoline. Part of the on 900 C calcined catalyst powder is analyzed; the powder contains 0.24% by weight of chromium and 0.23% by weight of aluminum.

In an autoclave with a stirrer (3.2 liters), 1500 ml of dry Gasoline introduced, to which 40 ml of catalyst suspension are then added. Then 0.4 ml of a 1 molar TIBA solution in gasoline

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added, after which the reactor closed and with ethylene with 5% hydrogen

ο is brought to pressure. The content of the autoclave is brought to 85 ° C heated and polymerized under a total pressure of 4 atm for one hour.

The polyethylene yield is 192 g, which corresponds to an activity of 973 g per mmol of chromium per at ethylene pressure per hour. The results of the sieve analysis are:

5 wt% <40jU; 11 wt% <70μ; 22% by weight <125μ; 48 wt% <250Ai; 73% by weight <420 β and 87% by weight <60OyU. From these values it can be calculated that the mean particle size is 400 ^ and the uniformity coefficient is 1.3. The polyethylene contains more than 10% by weight fine material, but also 13% powder with a particle size of more than 600μ. The polyethylene disperses strongly and easily bridges.

Comparative example B

According to the method described in Comparative Example A, a catalyst is prepared in which the amount of chromium acetylacetonate is 5.7 mmol and 8.5 mmol of dibutylmagnesium are used instead of triisobutylaluminum. The catalyst contains 0.22% by weight of chromium and 0.19% by weight Magnesium on Aerosil 200 V.

b _i _Pol2merisation_von_Athjlen

Ethylene is polymerized in the same way as in Comparative Example A, 1.2 ml of 1 molar triisobutylaluminum being added to the polymerization medium. 154 g of polymer are obtained, which corresponds to an activity of 853. The results of the sieve analysis are: 4% by weight <50μ; 9% by weight <70 //; 18% by weight <125 / i; 42% by weight <250μ; 67% by weight <420% and 84% by weight <600 β. A mean particle size of 400 β and a uniformity coefficient η = 1.4 are calculated from these values. The polyethylene powder disperses strongly, as in Comparative Example A, and easily forms bridges in filling hoppers.

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Example 1 fS ^

a ^ manufacture ^ es ^ ataljrsators

In a 1 liter flask operated with a stirrer, a reflux condenser and a feed is provided, 20.78 g of chromium (III) acetylacetonate (59.5 mmol) in 400 ml of dry mineral spirits (Boiling range 65-85 C) suspended.

This suspension is heated with simultaneous stirring until the Gasoline boils, after which 45 ml of undiluted triisobutylaluminium drop by drop (TIBA). The result is a dark brown-green solution that only contains traces of solids. After filtration will be 15.5 ml of the solution obtained in this way was added to a suspension of 20 g of washed Ketjen F-7 in 250 ml of dry gasoline. That washed Ketjen F-7 is predried, i.e. 16 hours at 120 ° C been heated.

Ketjen F-7 is a silica gel marketed by Ketjen with a

2
Pore volumes of 2.1 cm / g and sodium content of 500 ppm. With this carrier only low yields with activities of less than 100 g of polyethylene per mmol of chromium per at ethylene pressure per hour are achieved. A Ketjen F-7 is used for this experiment, the sodium content of which has been brought back to 5 ppm by an extra wash-out treatment of the gel, the pore volume being increased

1.6 cn / g has decreased. The mean particle size is 110 β and the uniformity coefficient ή = 2.0. If this silica gel 6 hours

is heated to 900 C, the pore volume does not change. If not washed Ketjen F-7 is heated to 900 ° C for 6 hours, the pore volume

G
lumen from 2.1 to 1.7 cm / g.

After a short time, the dark colored solution has become discolored and the silica gel carrier material has taken on color. The silica gel carrier with the chromium compound deposited thereon, the light gasoline is evaporated from the dispersant, after which it is separated the powder obtained in this way is dried under vacuum at 50 ° C. for 16 hours. The powder is then placed in a rotary kiln heated to 900C in a stream of dry air. The warm-up time is about 1 hour and the powder is held at 900 ° C. for 6 hours. To After cooling, the catalyst powder is suspended in so much gasoline that the concentration is 0.0048 mmol of chromium per liter of gasoline. Part of the Catalyst powder calcined to 900 ° C. w: 0.50% by weight of chromium and 0.78% by weight of aluminum.

Catalyst powder calcined for 900 C is analyzed; the powder contains

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1500 ml of dry gasoline are introduced into an autoclave with a stirrer (3.2 liters), to which 10 ml of catalyst suspension are then added. Then 0.3 ml of a 1 molar TIBA solution in gasoline is added, after which the reactor is closed and pressurized with the aid of ethylene with 10% hydrogen. The content of the autoclave is ^{heated to 85 °} C. and polymerized for 90 minutes under a total pressure of 7 atm.

The polyethylene yield is 195 g, which corresponds to an activity of 575 g polyethylene per mmol Qiian per at ethylene pressure per hour corresponds.

The results of the sieve analysis are as follows:

0 wt% <40 #; 0 wt% <70 β ; 5 wt .-% <125 (J .; 25 wt .-% <25Qt /;. 55 wt .-% <420fi and 85 wt .-% <600 # From these values are a mean particle size of 480 u and a Gleichmässigkeitskoeffizient calculated from 2.1.

Example 2

Example 1 is repeated, using only 5 ml of catalyst suspension are introduced into the reactor. The yield is 101 g, which corresponds to an activity of 595.

Sieve analysis of the polyethylene powder gives the following values: 0% by weight <40%; 0% by weight <70 U ; 4% by weight <125 U; 25 % by weight < 250 β ; 55% by weight <420μ and 87% by weight < QOOß.

A particle size of 460 u and a can be derived from these values Calculate the uniformity coefficient of 2.5.

Example 3.

The procedure described in Example la is repeated, wherein 20 g Crossfield MC can be used as a carrier. Crossfield MC is a by Joseph Crossfield 8s Son Ltd. (UK) launched

3 Silicaxerogel with a pore volume of 1.6 cm / g, a sodium content of 140 ppm, an average particle size of 105 u and a uniformity coefficient of 5. After 6 hours of heating to 900 ° C of

3 Crossfield MC the pore volume is still 1.57 cm / g.

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b _A Polymerization of ethylene

The polymerization is carried out in the manner described in Example Ib with a chromium concentration in the polymerization reactor of 0.010 mmol each Liters running. 0.6 ml of 1 molar TIBA are fed to the reactor. The yield is' 91 g, which corresponds to an activity of 900, -

Sieve analysis gives the following values: 0% by weight <40a; 0 wt% <70 ^; 4.8 0β * .-% <125µ; 30% by weight <250μ; 65 wt .-% <420μ and 97 wt -.% <6OOu From these values may be an average particle size of 370 μ and calculate a Gleichmässigkeitskoeffizient of 3.0.

Example 4 ' _ψ '

Example 3 is repeated, using the solution of chromium (III) acetylacetonate and triisobutylaluminum is added to 14.1 g of Crossfield MC, whereby the amounts of chromium and aluminum are reduced to 0.70% by weight and 1.09% by weight.

Sufficient catalyst is introduced into the autoclave that the chromium concentration is 0.018 mmol per liter; continue to be 0.3 ml of 1 molar TIBA solution was added. The yield is 165 g what corresponds to an activity of 840.

The polyethylene powder is very coarse, sieve analysis shows a mean particle size of 950μ and a uniformity coefficient ices from 4 to 4.5.

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Claims (4)

PATENT CLAIMS 1. Process for polymerizing a 1-alkylene having 2-8 carbon atoms, optionally with minor amounts of a maximum of 10 mol% of one or several other 1-alkylenes with 2 to 8 carbon atoms, preferably ethylene with a maximum of 2 mol% propylene and / or if desired Butylene, in the presence of a catalyst which is produced by the reaction of a Chromium-1,3-diketo compound of the formula Cr (OCR CR CR 0), in which R, R XaOw -X 2 and R "have the same or different meanings and each represent an alkyl group with 1-10 carbon atoms, while R can also denote a hydrogen atom, with an organometallic compound of a metal of group II or III of the periodic table, in the hydrocarbyl groups with 1-20 carbon atoms a carbon atom are bonded to the metal in question, combining this reaction product with an inert inorganic carrier, heating the reaction product of the chromium compound deposited on the carrier in a non-reducing environment to a temperature between 200 and 1200 C and then mixing the product obtained in this way with a Organometallic compound of an element of group II or III of the periodic table is obtained, characterized in that a silicon dioxide with an average particle size of at least 40 \ x and a uniformity coefficient of at least 2 is used as the catalyst support will. 2. The method according to claim 1, characterized in that a silica xerogel is used. 3. The method according to claims 1-2, characterized in that a silicon dioxide with a pore volume of at least 1.5 cm / g and a sodium content of at most 200 ppm is used as the carrier. 4. The method according to claim 3, characterized in that as a carrier Silicon dioxide with a sodium content of 150 ppm or less is used. -14- 809885/0963 ORIGINAL INSPECTED