DE2104024A1 - Process for the production of oils fmpolymensaten - Google Patents

Description

Concerning: "Process for the production; of olefin polymers "

The invention relates to a process for the production of olefin polymers by polymerization of olefins, the term polymerization also including copolymerization. The invention also relates to the polymers, for example polyethylene including copolymers of ethylene, which according to are produced by the process.

According to British Patent 1,057,728, ethylene can be produced under continuous conditions using a Ziegler catalyst stationary conditions are polymerized in two polymerization zones, with polyethylene in the first zone is formed and this is transferred together with the catalyst from this zone into the second zone, in which Ethylene is polymerized with the aid of the catalyst introduced from the first zone. In this type can polyethylene products are generated which have a desired broad molecular weight distribution and are particularly suitable for

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drive can be used for rapid blowing of bottles.

The Ziegler catalyst that can be used in this two-step process is generally obtained by reducing a Transition metal compound formed in which the metal in the normal maximum valence level is present, with an aluminum alkyl or an aluminum alkyl halide as Reducing agent is used, and the reduced transition metal compound obtained is mixed with an organo-metal compound e.g., an aluminum dialkyl halide which is used primarily as an activating agent for the transition metal compound works.

It has surprisingly been found that the polymerization of olefins, for example ethylene, is carried out in two stages can be improved by using a Ziegler catalyst in which the transition metal compound is reduced using an organomagnesium compound and an organometallic compound as an activating agent is incorporated. The invention relates to such a method.

The process according to the invention for the preparation of olefin polymers by polymerization of olefins in the presence of a catalyst, the polymerization in two consecutive Stages in the same polymerization zone or in different polymerization zones is carried out in such a way that the olefin polymer present in the reaction mixture at the end of the first stage together with the catalyst ax its Help the polymer has been formed, is also present in the reaction mixture of the second stage, is characterized by that one works under conditions that this works out

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the polymer removed from the second zone is a mixture contained in the first and second zone formed polymers with viscosity numbers between 0.4 and 2 and between 3 and represents and is formed in such amounts that the desired polymer product has a flow parameter of 1.4 to 2.5 has and that a catalyst is used by reducing a transition metal compound in the normal Valence level made with an organomagnesium compound and activated with an organometallic compound.

This method can ^w to form a polyethylene or a mixture of polyethylene and ethylene-butene-1 copolymers are used as the olefin polymer end product ethylene-propylene copolymers or, for example, to the polymerization of ethylene. If the product forms a mixture, as shown above, the copolymer component of the mixture can be formed in one of these polymerization stages.

According to a preferred embodiment of the invention, the process can be carried out under continuous, practically stationary conditions in two polymerization zones, a polymer, for example polyethylene, being formed in the first M of this zone and being transferred together with the catalyst from this zone to the second zone , in which ethylene is polymerized or copolymerized, for example with propylene, in the presence of the catalyst fed in from the first zone and the desired polymer is withdrawn from the second zone. This polymer product, which can be a mixture of the respective copolymers formed in the zones, is such that the polymers from these zones have viscosity numbers of 0.4 to 2.0 or 3.0 to 20 and that they have viscosity numbers of such relative amounts are present that the polymer end product has a flow

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parameter (which is defined below) in the range from 1.4 to 2.5 »preferably from 1.7 to 2.2. The invention includes olefin polymers and copolymers, in particular, but not exclusively, ethylene polymers and copolymers obtained with the aid of the process.

There are certain advantages to using a titanium tetrachloride catalyst system with Magnesium is reduced, related in a two-stage polymerization process. Venn e.g. the conditions are such that a low molecular weight polymer is formed in the first "reactor and a copolymer high molecular weight is formed in the second reactor using low temperatures the low molecular weight product of the primary reactor has a broad molecular weight distribution of the end product, resulting in a high sensitivity to shear forces and leads to better processability.

Broader molecular weight distributions can also be obtained by changing the temperatures in the primary and in the secondary reactor, but this would lead to lower polymer yields, based on the catalyst, lead, the use of higher pressures increasing the yield again.

The activity of the catalysts is such that there are no residue extraction stages are required in a two-step process. In fact, the reactors are working as found became »very good and were after a few hundred hours of work very clean. The product was consistently satisfactory, especially when it was made at the low polymerization temperature, with the broader MoIe-

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Molecular weight distributions in the individual reactors contributed to the broadest net molecular weight distribution to create. Because of the fine catalyst particles the products have a more favorable molecular weight balance distribution and the quality of the bottles made from the polymer.

The Ziegler catalysts that are used in carrying out the process according to the invention are transition metal compounds, whereby the transition metal is present in a valency level below the normal maximum valency level and these compounds by! reduction below φ regulated conditions using a certain type of reducing agent have been established, wherein the reducing agents can be an organomagnesium compound may or may contain and then the reduced transition metal compound obtained with an organometallic compound is activated

Examples of improved Ziegler catalysts that can be used in the practice of the invention are Subject of other registrations.

Many types of organomagnesium compounds can be used as reducing agents in the manufacture of catalysts for Ver ™ application when carrying out the method according to the invention Compounds of the type often referred to as Grignard reagents are preferred because these Compounds are readily available and often commercially available. However, other organomagnesium compounds are also available suitable and may be preferred in some cases. For example, organomagnesium compounds of the formula R MgOR, in

R and R each represent a hydrocarbon group, used as a reducing agent for the transition metal compound will. Such compounds are hereinafter referred to as alkyl

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magnesium alkoxides called. The term "Grignard reagent" is sometimes used narrowly to denote etherified organoaagnesium halides of the formula B Mg X, where R is a hydrocarbon group and X is a shark atom, but it should be clarified that the term "Grignard reagent" is The following is used in the broadest sense and includes all types of organomagnesium compounds formed by the reaction between an organohalide of the formula HX and magnesium metal, whether or not they are prepared in the presence of ether. For example, the term "Grignard reagent" as used here includes not only hydrocarbon magnesium halides of the formula R Mg X _1, which may optionally be solvated, but also the hydrocarbon magnesium compounds of the formula E ^ g and compounds of a composition represented by the formula (BpMg) (RMgX) ,, is characterized as they are formed when the Grignard reaction is carried out in an inert, ie non-solvating, solvent such as a hydrocarbon. Particularly good results have been obtained using alkyl magnesium halides, and particularly the associated forms of such compounds are suitable as obtained when a hydrocarbon halide of the formula RX is reacted with magnesium metal in a liquid hydrocarbon solvent. Compounds of the above formulas, where X is a chlorine, bromine or iodine atom, may be preferred, while the optimum activity in the activated catalysts finally obtained can be obtained by using Grignard compounds of the above formulas in which R is an alkyl group is at least 4, preferably at least 8 and in particular 12 carbon atoms. Grignard compounds are known from the chemical literature, where processes for their preparation are also described.

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The term "improved Ziegler catalyst" is used in The following is used to denote a catalyst which is produced by a process or a procedure is, including a reduction stage below Use of an organomagnesium compound or compounds is carried out as a reducing agent. Any compound or any mixture of compounds of a transition metal produced by an organomagnesium compound can be reduced from the normal maximum valence level of the metal to a lower valence level and that in the reduced fora can operate as a catalyst for olefin polymerization in the presence of an organometallic activating agent can be used to carry out the method according to the invention. Any organometallic compound can also be used which is known to be useful in the activation of Ziegler catalysts for olefin polymerization are to the reduced transition metal! connection to activate. Thus, suitable transition metal compounds are the halides of titanium, vanadium, chromium, molybdenum and Zirconium and suitable organometallic compounds are aluminum, zinc and magnesium alkyls and alkyl halides. As As is well known, the most commonly used Ziegler catalysts are those produced by reducing a tetravalent titanium compound, e.g., titanium tetrachloride, and activating the obtained trivalent titanium compound with an aluminum alkyl compound or an aluminum alkyl halide.

When a Grignard compound is used as a reducing agent in the When practicing the invention, the (Jrignard compound suitably prepared by heating magnesium and the corresponding alkyl halide in a hydrocarbon solvent such as isooctane. Under In these conditions the compound is often considered to be more insoluble

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Substance formed, which is a slurry in the solvent forms. When an alkyl magnesium alkoxide compound is used as a reducing agent, it can be used in any known one or prepared in a suitable manner. Usually the alkoxide obtained is used as a solution in an acyclic aliphatic hydrocarbon formed as a solvent.

The slurry or solution of the organomagnesium compound can with titanium tetrachloride according to a procedure known for the reduction of this compound to titanium trichloride implemented. However, it has been found to be most beneficial to use the slurry or solution with a Solution of titanium tetrachloride in the same hydrocarbon solvent, how it was used to produce the organomagnesium compound was used to implement.

The titanium trichloride can with the aluminum alkyl compound mixed as an activating agent and then fed into the polymerization tank or the trichloride and the aluminum activating agent can be fed separately to the polymerization vessel. It can all common organometallic activators used in the manufacture of Ziegler catalysts, be used to activate the titanium trichloride, the has been abolished by reduction, but the aluminum dialkyl halides and especially the aluminum trialkyl compounds are preferred.

The polymerization can be carried out in a reaction medium which consists of a dispersion of the improved Ziegler catalyst consists in an inert liquid diluent, and the reaction medium can be continuous can be removed from the first zone and continuously transferred to the second zone and the reaction medium can be carried out continuously from the second zone to isolate the desired poly-

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merisate products are deducted

In the following, the quantities referred to as "flow parameters" are "melt index flow parameters" as obtained with a Davenport melt indexer, as used, for example, in accordance with the melt index determination method according to ASTM 1238 / 57T. To determine flow parameters in this way, the melt index of the polymer is measured at any suitable temperature (the flow parameters mentioned in this description were measured at 190 ° C) and expressed in g / 10 min using the Davenport Sehmelz indexer with weights of 21, 6 kg (melt index "A") and 2.16 kg (melt index "B ¹¹ ) and the flow parameter (N) is derived from the relationship:

N = log £
B.

calculated.

The viscosity number of a polymer expresses the weight average molecular weight of the polymer and can be determined in the usual way by measuring the viscosity of a dilute solution of the polymer and calculating it. In this specification, the viscosity numbers using a 0.1-wt were obtained .-% solution of a polymer in decalin at 120 ⁰ C.

If, as is preferred, the process according to the invention is carried out in two successive polymerization zones the polymerization conditions in each zone can be adjusted according to the requirements of the simultaneous production are regulated by olefin polymers of significantly different molecular weights in these zones. By

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seems to be using the same catalyst in both zones a successive growth of the polymer chains of different Chain length to be carried out, depending on the polymerization conditions prevailing in a zone, this being Growing in close proximity to the catalyst particles is carried out and this growth has such a degree of homogeneity in the Polymer product results which, surprisingly, not by physically mixing the two individual polymers containing reaction slurries (polymer suspensions in liquid media originating from separate Ziegler polymerizations carried out under conditions which lead to olefin polymers with significantly different molecular weights), is obtained, since it has been found that the polymer obtained as the end product in the work-up of such mixed reaction slurries shows unacceptable macro inhomogeneity.

When carrying out the invention in the preferred two-stage form, the polymerization conditions, among which each olefin polymer is formed, by selecting the appropriate polymerization temperature the presence, as required, of a molecular weight regulator to be regulated in each polymerization zone Prepare polymers of the desired viscosity number. The average time spent in each of these zones is regulated in such a way that the amount of polymer formed therein is so large that the molding parameters of the entire Olefin polymer product of the process is within the stated limits. For example, polyethylene ^ in, the first and second zones, the viscosity numbers between 0.4 and 2.0 and 3.0 and 20.0, respectively have, although it is equally possible, the higher molecular weight polymer in the first zone (corresponding to a viscosity number of 3.0 to 20.0).

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In this context, the term "polyethylene" includes a copolymer of ethylene in a minor amount Propylene or another α-olefin. Hydrogen is a preferred molecular weight regulator for use in practicing the invention, but other molecular weight modifiers can also be used be used. The general conditions under which hydrogen regulates the molecular weight can be used in the Ziegler polymerization are known per se. When the present of hydrogen in the first polymerization zone, but ~ is not required in the second polymerization zone, W for example, dissolved hydrogen that is present in the reaction mixture from the first polymerization zone can be removed, e.g. by purging with an inert gas before entering into the second zone, although the low solubility of hydrogen in that is common in Ziegler polymerizations type of liquid media used usually makes it unnecessary to flush hydrogen between the remove both zones *

When carrying out the process according to the invention, ethylene can be present in one zone or in both zones a small amount, based on ethylene, of propylene or Jj Butene-1 are polymerized, whereby the in this zone or ^ Zones formed ethylene polymer an ethylene / propylene copolymer or forms an ethylene / butene-1 copolymer, up to 10% by weight, based on the copolymer, of Contains propylene or butene-1. The products of such a modified process either consist of (a) a mixture made of polyethylene and either ethylene / propylene copolymer or ethylene / butene-1 copolymer, or (b) from a mixture of ethylene / propylene copolymer or ethylene / butene-1 copolymer, depending on whether propylene or butene-1 is present in one zone or in both zones. Preferably that will

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Ethylene in the presence of propylene or butene-1 in just one polymerizes these zones and this is preferably the second zone, so that an ethylene / propylene copolymer therein or an ethylene / butene-1 copolymer with a viscosity number between 3 and 20 is formed.

The polymerization conditions used in these two zones can either be used in the production of homopolyethylene or in the preparation of a copolymer in one or in both zones according to the most favorable working conditions be selected and according to the need to avoid large-scale conditions that are practically impracticable, such as conditions that allow the formation of an impracticably small amount of one of the Polymer components in one of these zones would require. Thus, in principle, practicing the invention is like this Known to those skilled in the art and it exists within the limits set according to the invention for the viscosity numbers and the Flow parameters have a considerable breadth with regard to the particular Polymerization conditions necessary to achieve a desired polymer with a flow parameter in the range of 1.5 to 2.5 can be used so that the specific conditions usually to be selected are within those available The fluctuation range can be adjusted to the peculiarities of the polymerization equipment that is used as well as the general working conditions under which work is to be carried out.

When carrying out the process according to the invention, it is advantageous to use the polymer with the highest viscosity number, i.e. within the viscosity number range of 3 to 20, to produce in the second reactor, the polymerization in this reactor practically in the absence of water

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substance or in the presence of only the small amount of hydrogen that is in the reaction mixture that is withdrawn from the first reactor is carried over. Based on the general knowledge about Ziegler polymerization and from previously determined values relating to working conditions In each of these reactors of a particular factory used, it is possible to adjust the polymerization conditions select, which produce appropriate amounts of polymers of the desired viscosity number in each reactor. For example, if desired, a polymer of selected viscosity numbers in the range of 3 to 20 in the second reactor can produce the amount of polymer that is contained therein per unit of time to be generated at a selected polymerization temperature by selecting an appropriate residence time be set in the second reactor. The first reactor is then operated in such a way that a polymer a viscosity number in the range 0.4 to 2.0, the actual viscosity number being within the range for the polymer produced in the first reactor primarily by the requirements of the flow parameter of the polymer end product is determined, but to a lesser extent by the amount of polymer (a selected Viscosity number) that would be formed therein within the same period of time under the reaction conditions (Hydrogen concentration and polymerization temperature), the are required to form the polymer. The amount of polymer formed in the first reactor is as important as theirs Viscosity number, as the flow parameter of the polymer end product, which is formed by combining the polymers formed in the first and second reactor, both of the amount as well as the viscosity number of each of the polymer components depends. A certain amount of experimentation working conditions will usually be required to get the optimal working conditions for the first reactor

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determine and produce a polymer product that has the desired flow parameters. Such attempts are but not difficult if you already have work experience with the system used. Certain working conditions in the first reactor, e.g. the residence time used in it, are determined according to the relevant conditions set for the second reactor, since the two reactors are operated continuously in series. It must It can also be found that practice has small differences between the polymerization conditions used to operate of the plant are required, and under the given conditions can be eliminated by adding polymerization conditions in one reactor or in both reactors immediately are regulated and such changes are made as necessary from time to time ensure the continuous production of a polymer with the desired flow parameters.

When ethylene is polymerized in the presence of a small amount of propylene or butene-1, the high initial activity allows it of the fresh catalyst has lower amounts of dissolved propylene or butylene in use and, consequently, propylene or butylene can be added to either the first or the second reactor. It can be beneficial to that To carry out copolymerization in the first reactor if there is an immediate recycle process for the solvent is used because the solvent can be expected to contain small amounts of propylene or butene-1.

The invention is illustrated in more detail by the following examples.

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example

According to the invention, this example explains the production of an olefin polymer by using 1. ethylene and 2. ethylene and propylene as olefin monomers in the two stages of a polymerization which is carried out under different polymerization conditions. The polymerization was carried out in a reactor with a capacity of 100 cm. For practical reasons, in. This small scale, two reactor operations were simulated by the conditions in which a reactor after a certain time were changed AEK and was not transferred to the reactor contents in the second reactor.

A titanium trichloride catalyst slurry was prepared by adding 20 mmol of a 2m titanium tetrachloride solution in an aliphatic hydrocarbon fraction boiling from 90 to 110 ° C to a well-stirred solution of 35 mmol C ^ HocMgBr ^ _n <] qq _m i toluene at - 30 ° C. A brown precipitate was obtained. This was allowed to settle and washed 5 times in succession by replacing the supernatant liquid with fresh hydrocarbon. %

The reactor of 1,900 cm made of stainless steel was charged with 1500 ml of the hydrocarbon fraction, the temperature brought to the desired level and 0.75 mmol of Al (C ^ p ₂ ,), as a molar solution in the hydrocarbon and 0.075 mmol of titanium trichloride in the form of a added to the slurry prepared as above. An inert atmosphere of pure dry nitrogen was maintained during these process steps. The reactor was closed and the pressure was increased to 7 kg / cm by injecting a mixture of ethylene and hydrogen in the desired proportions.

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There was a continuous total gas flow through the Maintained reactor at 300 l / h and the temperature was controlled by circulating oil from a thermostat kept the reactor jacket constant. After a predetermined time, the temperature was reduced to that for the second stage of the process required temperature changed. The flow of hydrogen was stopped and propylene was in the desired Amount mixed with ethylene. In this second stage, a total gas flow rate of 200 l / h was maintained. The conditions used for the two stages in three separate approaches are as follows Table I reproduced. At the end of the period of time that was required to obtain the desired amount of copolymer! Sat in To obtain the second stage, the gas flow was stopped, the pressure was reduced to atmospheric pressure and the reactor contents removed. The hydrocarbon fraction was removed by steam distillation and the polymer powder was isolated and dried. No ash removal or other cleaning operations were required. Some of the properties of the polymers are shown in Table I. Because of the high titanium trichloride yield that was achieved, the Polymers had an excellent color and were not corrosive to cast steel. (In the numerical classification the corrosion properties are numbers of 6 and below still acceptable)

TABLE I:

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TABEL I. 726/174 4-5 726/186 726/190 3 1.75 1.75 1st stage Duration, h 85 1550 90 90 Temp., ⁰ O 60 40 45 H ₂ ,% 1.1 1.35 1.2 Polymer IV *) 0.5 1.0 0.8 2nd stage Duration, h 80 80 75 Temp., ^G 18th 18th 10 Propylene,% 5.3 4.4 6.3 Polymer IV Polymer: 16.0 25.5 25.0 yield kg / g TiGl ₅ , 0.46 0.46 0.14 Melt index g / 10 min 1.98 1.79 1.95 flow parameters 0.30 0.30 0.30 Bulk weight clit g / ml 0.955 0.945 0.948 density g / ml 92 92 93 coloring 6th 4-5 Corrosiveness Critical 1190 500 Shear force **) sec ~ '

*) Viscosity number as measured above

**) The critical shear force is defined as the extent the occurrence of melt breakage during extrusion of the polymer. It depends on the melt index and on the molecular weight distribution. For example, the polymer with a melt index of 0.14 has a

- 18th

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lower critical shear force than the polymers with a melt index of 0.46. The critical shear forces for polymers with flow parameters of 1.50 "are only 100-150 sec" ¹ (MI = 0.46) and less than 100 sec " ¹ (MI = 0.14) for comparison.

Example 2

(a) Preparation of the Grignard reagent

There were 209.4 ml of butyl chloride, 333 ml of ether and 1457 ml Isooctane mixed with 10 ml of butyl chloride as initiator.

The mixture was placed in a 3 1 three-necked flask to magnesium, with a nitrogen flow of 100 ⁰ C (the reflux temperature of isooctane) was used, and was slowly stirred. After the addition, the mixture was allowed to cool and settle. Supernatant liquid (Grignard solution) was transferred to a flask under nitrogen through a tube with a sintered filter. A yield of 85 %, based on n-butyl chloride, was obtained.

(b) Preparation of the catalyst

There were 437 ml of Grignard solution (at 430 mmol / 1) in a Cylindrical 1 1 reactor with a flat bottom placed under a protective atmosphere of nitrogen and stirred. A solution of 62.4 ml of titanium tetrachloride in isooctane (2 mol / l) was drawn from a funnel under nitrogen over 30 minutes added at 22 ° 0. The suspension was diluted for use in the polymerization reactor.

(c) polymerization

It was a cylindrically shaped reactor of 40 1 working

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capacity with a propeller stirrer in a central in Equipped reactor arranged exhaust pipe. The reactor was continuous with several streams of separate Feeding tanks and the slurry became continuous removed according to known stationary working conditions. The liquid feeds were through Dosing pumps are added and the gases through compressors and pressure equalization valves.

The catalyst was added as a very dilute slurry (about 1 mmol / 1) from a stirred addition vessel pumped in a nitrogen protective atmosphere. In a similar way Thus, in the form of a dilute solution, the aluminum alkyl compound became pumped in as an activating agent. Additional solvent was added through the sight glass for the reactor liquid level added to keep this free from the polymer. It became a mixture of ethylene and hydrogen certain composition for adjusting the molecular weight of the polymer by the reaction mixture circulated from a buffer tank into which ethylene is fed at the rate of polymerization became. A high recycle ratio was maintained.

The product slurry was out of the reactor through a Removed vent valve which opened and closed automatically so the slurry level in the reactor was very low Showed fluctuations.

The slurry was transferred to a second reactor operating at a lower pressure and under conditions worked that a higher molecular weight product was obtained. The construction and operation of this Reactor corresponded to that of the first reactor. The second reactor

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was charged with a stream of additional aluminum alkyl compound and solvent. Propylene was made along with the Ethylene-hydrogen mixture added.

The withdrawn slurry was immediately drawn into a steam nozzle wiper, thereby removing the solvent Was driven off in a condenser and transferred the water-wet polymer powder into a receptacle. The powder was batch dried in an oven.

Typical reaction conditions, the steady state concentrations and the properties of the products are shown in Table II.

TABLE II:

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Reactors

TABLE II

(d) Product Features

The product has been extruded and molded,

Characteristics:

Bulk weight

Melt index

Jmolding parameters

Critical Shear

Critical shear stress density

Bell load tear strength Izod impact strength

Stretch limit

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R2

Slurry temp. ⁰ G 65 85 50 Reactor pressure, bar 9.0 21st 4.7 Rate of polymerization
g / l / h ' 21st Dwell time, h 6.3 3.8 Sludge concentration, % by weight 18th 20th Al (Oct) ₃ mmol / l 2.0 1.7 TiOl, mmol / 1 0.135 0.097 Yield kg / g 6.6 2.9 Total yield kg / g - 9.5 Propylene feed g / h - 42 Ethylene - in gas charge, vol% 15 21.7 Hydrogen -'in gas charge,
Vol% 17.5 Melt index g / 10 min Net: 0.43

It had the following

0.35 g / ccm 0.43 g / 10 min 1.97

1100 sec "" ¹

3.5 dynes / cm χ 0.956 g / ccm

> 400 h ASTM

2.1 joules / 12.7 mm ο notch

260 kg / cnT (500Q. ^ Joules) -22-

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Claims (11)

1A-39 074 - 22 - PATENT CLAIMS Process for the production of olefin polymer by polymerizing olefins in the presence of a catalyst, the polymerization in two successive stages in the same polymerization zone or in various polymerization zones is carried out in such a way that what is present in the reaction mixture at the end of the first stage Olefin polymer together with the catalyst with the aid of which the polymer was formed, also in the Reaction mixture of the second stage is present, characterized in that under conditions works so that the polymer removed from the second zone is a mixture of those formed in the first and second zones Represents polymers with viscosity numbers between 0.4 and 2 or between 3 and 20 and is formed in such amounts is that the desired polymer product a / J? lassparameter from 1.4 to 2.5 and that one has a catalyst used, the reduction of a transition metal compound in the normal valence level with an organomagnesium compound and activated with an organometallic compound. 2) The method according to claim 1, characterized in that the olefin is polymerized ethylene. 3) Process according to claim 1 or 2, characterized in that a polyethylene is used in the first stage produced with a viscosity number between 0.4 and 2.0. - 23 - 109832/1571 1A-39 074- - 23 - 4-) Method according to claim 1 to 3 »characterized in that a polyolefin product with a Establishes flow parameters in the range from 1.7 to 2.2. 5) Method according to claim 1 to 4 ·, characterized in that the polymerization in at least carries out a stage in the presence of hydrogen. 6) Process according to claim 1 to 5, characterized in that the transition metal compound is used a tetravalent titanium compound is used. 7) Process according to claim 1 to 6, characterized in that the organomagnesium compound is used uses the product formed in the reaction of metallic magnesium and a hydrocarbon halide will. 8) Method according to claim 1 to 7 »characterized in that one is used as an activating agent Trialkylaluminum compound is used. 9) Method according to claim 8, characterized in that there is a trialkylaluminum compound of the formula Al R, used, in which R is one Means an alkyl group with more than four carbon atoms. 10) Process according to claim 1 to 9 »characterized in that ethylene is used in one stage or in both stages in the presence of a small amount of propylene or butene-1 polymerized with respect to ethylene, the Ethylene polymer formed in this stage or in these stages on an ethylene / propylene copolymer or an ethylene / butene-1-Oopolymerisat up to 10 wt .-% ethylene - 24-109832/1571 1A-39 074- - 24 or butene-1, based on the polymer weight. 11) Process according to claim 1 to 10, characterized in that the polymerization is carried out in Carries out the presence of an inert liquid diluent. 109832 / 1S71