JPS6022001B2 - α-olefin polymerization catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to supported catalysts for the polymerization or copolymerization of Q-olefins at low temperatures.

In particular, the invention relates to a threaded support for said catalyst. It is known that Q-olefins can be polymerized at low temperatures with Ziegler catalysts, which are generally formed from a catalyst component consisting of titanium tetrachloride in combination with an organoaluminum compound, and the reaction can be carried out in suspension, in solution or in the absence of diluents and solvents. It is done in Polymerization processes are also known in which the catalyst component is supported on a solid, generally inorganic support. Thus, for example, according to US Pat. No. 3,166,442, polymetallic compounds are immobilized on silica, alumina or similar supports with reactive hydroxyl groups on the surface. Other carriers suitable for this purpose are the divalent metals hydroxychloride and divalent metals.
These latter compounds are substantially free of hydroxyl groups and are generally selected from oxides, sulfates, phosphates, silicates and polycarboxylates of calcium and magnesium. For a better understanding of these catalysts, reference is made to Belgian Patent No. 65067y, French Patent No. 144 Patent No. 2 and British Patent No. 1140 Private. The above-mentioned catalysts generally require the use of relatively high pressures for polymerization, or rather produce only low polymerization activity, or both, and yet the final product is It is necessary to wash the final product in order to purify it from the residue of the system.

According to other known methods, as described in British Patents 1314784 and 131577, supports for olefin polymerization, such as alumina, silica and magnesium oxide, increase the activity of the final catalyst. The polymer is halogenated to increase its strength, thereby avoiding costly final cleaning of the polymer.

Other active catalysts include German published patent publication DASI93907
It is obtained by pretreating a divalent metal halide with an electron donor as described in the specification of No. 4. Although these catalysts have high activity for olefin polymerization, it is not easy to control the average molecular weight of the polymer, and the resulting products are therefore often difficult to process due to their high melt id dex values. It is difficult to do so.

It has been found that the shortcomings of these known techniques are overcome by employing a new Ziegler monocatalytic support for the polymerization and copolymerization of Q-olefins.

Accordingly, it is an object of the present invention to provide a new support with organic properties suitable as a catalyst for the polymerization and copolymerization of Q-olefins at low pressures.

Another object of the invention is to provide a catalyst comprising a carrier as described above.

Further objects of the invention will become apparent from the description below.

This invention relates to a Ziegler soot system formed by a combination of an organoaluminum compound and a catalyst component consisting of titanium tetrachloride supported on a carrier, in which the carrier combines magnesium chloride with an aliphatic alcohol and a fluorine-containing compound. an active solid flange obtained by reacting the rust body with fluorine 2 to fluorine at a temperature of about 100°C to about 200°C;
15% by weight and alcoholic hydroxyl groups 0.4~
To provide a Ziegler soot system containing 11% by weight.

According to the invention, the catalyst support is made from magnesium chloride, an aliphatic alcohol and a fluorine-containing compound.

Alcohols are generally selected from those containing 1 to 5 carbon atoms per molecule, with ether/al being preferred. Fluorine-containing compounds generally include hydrofluoric acid (hydrogen fluoride), ammonium fluoride, phosphorus fluoride, or mixtures thereof;
or more generally an organic or inorganic fluorine-containing compound that has a fluorinating effect under the reaction conditions. Fluorine itself is also useful for this purpose. When manufacturing the carrier,
The above-mentioned reactants are generally brought into contact and
heat-treated at a temperature of

In practice, the reaction is carried out by preparing a solution of the other reactants in the selected alcohol and heat-treating the resulting solution to remove excess alcohol. An inert diluent such as an aliphatic or aromatic hydrocarbon having a higher boiling point than the alcohol used may be present in the solution. To prepare the solution, the magnesium chloride is mixed directly with the selected alcohol and fluorinating agent, as well as any diluent that may be present. In a preferred embodiment, the fluorinating agent is dissolved in the alcohol of choice and a diluent such as magnesium chloride suspended in n-dodecane is added to the resulting solution. After the magnesium chloride has dissolved, the mixture is heated to remove excess alcohol. This can be done by simple evaporation or by processing in a fog dryer. In the first case, the support is obtained in the form of hexagonal scales with an average particle size of 10 to 100 microns. In the second case, depending on the operating conditions, the carrier is again obtained in the form of spherical particles with an average particle size in the range of 10 to 100 microns. Supports with desired particle sizes can therefore be obtained by adjusting the processing parameters. The carrier can also be "dried" by mixing the desired amounts of ingredients without excess alcohol.
It can also be created in a state. The resulting mixture is then reacted, optionally in the presence of an inert diluent. In the case of this dry method, an appropriate particle size of magnesium chloride (generally about 60 microns) is selected, and the degree of dryness of this magnesium chloride is important, and its moisture content is preferably about 1.
% by weight or less. The degree of drying is less severe when the carrier is produced in solution than in dry processes, in which case magnesium chloride with a water content of up to 5% by weight can be used. The reaction temperature used in the preparation of the carrier is generally from about 1000C to about 20000C.

At temperatures below the lower limit temperature, no reaction occurs between the reactants, or even if it occurs, the degree of reaction is undesirably low. If the temperature exceeds the above upper limit temperature, the specific surface area of the resulting compact will be small and the catalyst will have low activity. Generally, best results are obtained at a temperature range of about 120 qo to 16 qo. The fluorine content of the carrier is kept in the range from 2 to 15% by weight, with less than 2% fluorine having no significant beneficial effects.
Moreover, if the amount is more than 15% by weight, a catalyst with low activity and low productivity will be obtained. Best results are obtained when the fluorine content in the carrier is in the range of 3 to 1% by weight. The fluorine content of the carrier essentially depends on the amount of fluorinating agent used in the preparation of the carrier. The content of alcoholic hydroxyl groups in the carrier is 0.4
~11% by weight; below 0.4% by weight, no significant benefit is obtained, and amounts above 11% by weight have undesirably high meltidex values and also result in polyolefins with high wax content. can get.

Best results are obtained by using carriers with an alcoholic hydroxyl content of 4 to 9% by weight. The amount of alcoholic hydroxyl groups remaining in the support essentially depends on the temperature chosen for the reaction, the values of which have been indicated above. Temperature therefore constitutes a fundamental parameter for adjusting the alcoholic hydroxyl content of the carrier. Although the pressure at which the carrier is produced does not require any strict limits, the carrier is generally produced at atmospheric pressure or at slightly elevated pressure, for example up to 1 kg/kg.

The supports obtained by the above-mentioned method have higher porosity and higher specific surface area values than supports which differ by simply treating magnesium chloride with an alcohol, such as ethyl alcohol, according to a formula of known techniques. A typical support according to the present invention has a porosity of about 0.75 ['g] and a specific surface area of about 70 g/g, whereas a known representative support that does not contain fluorine has a porosity of about 0.75 ['g]. It has a porosity of about 40 w/g and a specific surface area of about 40 w/g. Moreover, the action of fluorine imparts greater surface acidity to the support, possibly resulting in the formation of bodies such as magnesium fluoride, alkyl fluoride, etc. For all these reasons, the carrier according to the invention is defined as a fin body. The above-mentioned support according to the invention is reacted with titanium tetrachloride.

The reaction between the support and titanium tetrachloride is carried out using conventional methods.

The titanium tetrachloride is added to the carrier by dispersing or dissolving it in an inert carrier, generally paraffin (eg, n-heptane, n-dodecane, etc.).

Although the processing temperature here does not need to be strictly limited, it is generally from the ambient temperature (20q0 to 25°C) to about 150°C. The treatment time is the period necessary to bond the desired amount of titanium to the carrier, and the desired amount of titanium is from 0.05 to 15% by weight, preferably from 1 to 5% by weight of the weight of the carrier. Finally, if an excess of titanium tetrachloride is used over the amount immobilized on the support, the excess is removed. In general, the interaction conditions such as relative amounts and interaction times are 0.03 to 5% by weight, preferably 0.5 to 5% by weight, taking into account that a portion of the hydroxyl groups contribute to the interaction with titanium tetrachloride.
Adjustments are made to obtain a supported catalyst component with a hydroxyl content of 4% by weight.

The fluorine content of the catalyst component supported on the carrier is generally between 1 and 1.
4% by weight, but best results are generally obtained with values between 3 and 8% by weight.

The catalyst portion thus obtained is activated by adding an organoaluminum compound.

Suitable organoaluminum compounds may be aluminum alkyls, halides or hydroxides of aluminum alkyls, or even Grignard compounds. A suitable metal is aluminum. An example of an organoaluminum compound is A (
C melon) 3, A〆 (C2 day 3) 3, A〆 (iso-C44)
3, A〆 (C2 day 5) 2C〆, Aso (C2 &) 2Br,
A〆(C2 day 5) 2 days, Aso(isoC44) 2 days and A〆2(C2 day 5)3C〆3. The best results are obtained with aluminum alkyls or with halides or hydroxides of aluminum alkyls, especially with triethylaluminum and triisobutylaluminum. The molar ratio of organoaluminium compound to titanium tetrachloride (this latter compound is bound to the support) in the catalyst does not need to be particularly strictly defined, but is generally 5.
It can vary from 0:1 to 1000:1, with preferred values being about 100:1 to 500:1.

The catalyst according to the invention has high activity and high productivity in the polymerization of olefins, especially in the polymerization of ethylene. In particular, other things being equal, the catalyst of the present invention has a higher productivity in grams of polymer per hour per gram of catalyst than a conventional magnesium chloride supported catalyst treated solely with alcohol. It is large in size and has a high activity expressed as k9 of polymer per hour per gram of titanium. Such a typical conventional press has a fixed amount of titanium of about 5% by weight, and 1g of catalyst.
A catalyst with a productivity of about 1,000 polyethylene units per hour is produced.

The residual titanium content of such polyethylene is approximately 5 to IQ
It's blood. Typical examples of carriers of the present invention have titanium fixed therein in an amount of about 2% by weight or less, with a titanium content of about 2% by weight or less per gram of catalyst.
A catalyst with a productivity of about 2000 polyethylene fibers per hour is produced.

The residual titanium content of such polyethylene is about 1 titanium or less. The basic advantage of the catalyst of this invention is that the average molecular weight of the polyethylene, ie its melt index, can be easily adjusted. This adjustment essentially depends on the amount of fluorine present in the carrier, taking into account the fact that fluorine promotes the formation of high molecular weight polymers and alcoholic hydroxyl groups promote the formation of low molecular weight polymers. This is achieved by appropriately determining the amount and proportion of alcoholic hydroxyl groups.

Therefore, it can be obtained by appropriately measuring the amounts of the two types of components within the range of the above-mentioned values. The catalysts of this invention are useful in the polymerization or copolymerization of Q-olefins having 2 to 6 carbon atoms per molecule and are particularly suitable for the production of polyethylene.

Polymerization can be carried out in the liquid phase, in the presence of a solvent or diluent, or even in the absence of a solvent or diluent.
The polymerization temperature can vary over a wide range and generally varies from -8 to 0 to 200C, preferably from 30 to 100C.

The pressure used during polymerization is 1 to 30/m, preferably 3 to 3
It is 0k9/th.

The catalysts of the invention have high activity in all cases in a low pressure range, for example under pressures of the order of 5k9/m. The average molecular weight of the resulting polymer can be influenced not only by the composition of the support, but also by adding modifiers such as alkyl halides or organometallic compounds of zinc and cadmium in the reaction medium, or by controlling the polymerization by the presence of hydrogen. Affected by what you do below. In all cases, it is possible to reliably control the properties of the polyethylene produced to the desired values within the following ranges: melt index (DIN 53735) from 0.1 to 20, crystallinity from 50 to 84%. sex,
and a density of 0.9 spots to 0.9 spots/' (DIN534
79).

This range of properties makes the polyethylene made by this invention suitable for any type of processing method such as extrusion, blow molding, etc. The present invention will be explained below with reference to examples, but the present invention is not limited thereto.

Example 1 27 g of anhydrous magnesium chloride in the form of scales are mixed under dry conditions with 4.8 g of ammonium fluoride for 30 minutes in a pre-dried glass container equipped with a filter and a porous corner membrane, and then mixed with n-dodecane. 100' and ethanol 150'
was added dropwise and the mixture was kept at ambient temperature for 1 hour after addition, then the temperature was raised to 110 qo and the mixture was kept under reflux until a completely clear solution was obtained.

The remaining alcohol was then evaporated from the solution at 130 pm over a period of 8 hours, leaving a carrier with a particle size of approximately 35 microns, 6.0% by weight of fluorine and 6.0% by weight of fluorine. The box contained % alcoholic hydroxyl groups by weight. The ammonium ion content was 5.05% by weight. Furthermore, the carrier had a porosity of 0.74/g and a specific surface area of 70/g. This carrier was immersed in 10% of titanium tetrachloride at 100 qo for 4 hours, the excess titanium tetrachloride was filtered out, and the resulting solid was soaked 5 times with 100% of titanium tetrachloride each time.
- Washed with decane. The resulting product was hexagonal and scaly, with a fluorine content of 6.0% by weight and a free alcoholic hydroxyl group content of 3.0% by weight. % by weight. The ammonium ion content was 5.5% by weight, the titanium content was 1.85% by weight, and the average particle size of the product was 35 microns. 10 pieces of this catalyst component were introduced into 2 pieces of n-heptane containing 1 piece of triethylaluminum, and the whole was placed in a 4-piece tube equipped with a pseudo frame machine.
It was placed in a steel autoclave with the same volume. Polymerization was carried out at a total pressure of 5k9/ground at 9〆○ (ethylene 3.5k9/ground,
The experiment was carried out under hydrogen (1.5k9/young).

After 2 hours, the reaction was stopped, at which point the catalyst was still active and a mass of white polyethylene 40 was obtained with the following properties: Melt Index 1 Density 0.95 g/'.

Furthermore, the activity of the catalyst was 1081 k9 of polyethylene ethylene produced per hour per gram of titanium, and the productivity of the catalyst was 2000 female polyethylene per hour per gram of catalyst. Example 2
Comparative Example A mortar was made exactly as described in Example 1, except that the ammonium fluoride was omitted.

The alcoholic hydroxyl group content of the carrier thus obtained was 8.5% by weight, the porosity was 0.5''g, and the specific surface area was 4.
It was 0 pillow'g. This carrier was impregnated with titanium tetrachloride as described in Example 1.

The resulting catalyst component was hexagonal and scaly, with an average particle size of approximately 35 microns and a free alcohol group content of 4. It was % by weight. Ethylene polymerization was carried out under the conditions of Example 1 using 10 parts of the catalyst component 9 and 1 part of triethylaluminum. After 2 hours of reaction, polyethylene 17 acid was obtained with the following properties: Melt Index 3 Density 0.9 base/secretion.

The productivity and activity of this catalyst were 875 female and 175 k9, respectively, expressed in the units given in Example 1. Example 3
Using n-heptane instead of n-dodecane, prepare a 200ml solution of the carrier components as in Example 1, and use this solution as a heating gas at an inlet temperature of 160°C and an outlet temperature of 1.
NYROATOM using 10oo of anhydrous nitrogen gas
The rumors were all over ZER.

The fog rate was about 20 flasks of solution per hour. In this way, the average particle size is about 50 microns and the porosity is 0.
Spherical particles with a specific surface area of 70/g were obtained.

Furthermore, the alcoholic hydroxyl group content of this carrier is 5.
5% by weight, fluorine content 7.5% by weight and ammonium ion content 6. % by weight. This carrier 2 female was treated with titanium tetrachloride according to the method described in Example 1.

In this way, the average particle diameter is 50 microns, and the titanium content is 1.5
A catalyst component of spherical particles with a fluorine content of 7.6% and an alcoholic hydroxyl content of 4.0% by weight was obtained. Ethylene is polymerized with 9 parts of this catalyst component and 1 part of triethylaluminum under the conditions shown in Example 1,
The following properties: Melt index 0
．． 9 Density 0.947g
A polyethylene film having / was obtained.

Using the units shown in Example 1, the productivity and activity of the catalyst were 19000 g and 1267 k9, respectively. Example 4 A carrier was prepared as described in Example 1 by evaporating a solution of the carrier components at 200° C. for 8 hours.

Thus the alcoholic hydroxyl content is 0. weight%
, fluorine content 4. A carrier was obtained with an ammonium ion content of 31% by weight. Furthermore, the porosity of this damaged body was 0.8'/g and the specific surface area was 25 m/g.
By impregnating the raccoon body as described in Example 1,
Titanium content 0.9% by weight, fluorine content 5% by weight, alcoholic hydroxyl group content 0. % catalyst component was obtained.

The carrier was hexagonal flakes with an average particle size of 10 microns. Polymerization was carried out as in Example 1, with the following properties: melt index 0.5 density
Seven polyethylene keys with 09 chicks/secretion were obtained.

The production and weight of this catalyst, expressed using the units described above, were 3800 g and 422 k9, respectively.
Example 5 27 g of powdered magnesium chloride were added to 1 cough of ammonium fluoride, mixed for 30 minutes at ambient temperature, and 100 g of anhydrous n-dodecane and 200 g of ethanol were added dropwise to the homogenized mixture.

The resulting mixture was kept at 2500 for 1 hour, then 120
A clear solution was obtained upon heating to .degree. tied solution 1
Evaporation was carried out at 20°C for 9 hours. Thus, the fluorine content 1
3.05% by weight, alcoholic hydroxyl base amount 0.
A carrier containing 10.75% by weight of ammonium ions and 10.75% by weight of ammonium ions was obtained. The porosity of the support is 0.53'/g;
The specific surface area was 50/g. The carrier is titanium tetrachloride 5
Titanium content 1.5% by weight and alcoholic hydroxyl group content 0 by treatment at 130oC for 5 hours.
．． A catalyst component having a fluorine content of 12.05% by weight and a total ammonium ion content of 9.75% by weight was obtained.

The catalyst component was in the form of hexagonal flakes with an average particle size of 15 microns. Using 10 parts of this catalyst and 1 part of triethylaluminum, ethylene was polymerized under the conditions shown in Example 1, and the following properties were obtained:
0.2 density
09 place/I obtained over 70 pieces of polyethylene.

The productivity and activity of the catalyst, expressed in the units given in Example 1, is approximately 350 and 233 k9.

Example 6 Two sides of anhydrous magnesium chloride were mixed at ambient temperature with 100' of n-dodecane, then 150' of ethyl alcohol.
' was added dropwise.

During the addition of the alcohol, gaseous hydrogen fluoride was bubbled into the mixture at a rate of 25 ml/hour. At the end of the addition, increase the temperature to 11
Bringing to 0°C gives a preferably clear solution, which is then heated to 1°C.
It was heated at 40°C for 8 hours and dried.

The fluorine content of the carrier obtained as a residue was 2.0% by weight,
The alcoholic hydroxyl content is 6.6% by weight, the average particle size is about 20 microns, and the porosity is 0. The thigh and specific surface area were 60〆/〆/〆.

Alcoholic hydroxyl groups 4. by impregnating the support under the conditions given in Example 1. 2.5% by weight of fluorine and 3.5% by weight of titanium. Average particle size containing % by weight of 20
A micron catalyst component was obtained. This is used to polymerize ethylene as described in Example 1 to obtain the following properties: Melt Index 1.8
200 pieces of polymer with a density of 09 pieces/secretion were obtained.

The productivity and activity of the catalyst is expressed in the above units as 100
There were 0 females and 333k9.

Example 7 Anhydrous magnesium chloride 25k9 was added to NH4F/HFI. 7
Treated with 100ml of anhydrous n-hebutane containing 9k9.

150 ml of absolute ethanol was added to the resulting suspension and the resulting mixture was kept at ambient temperature for 1 hour under heating and then heated to 100°C. A clear solution was thus obtained, which was fed into a NYROATOMISER with nitrogen circulation. The nitrogen inlet temperature is 200℃ and the outlet temperature is 12
It is 0oo. The solution supply rate is 20/hour.
The carrier thus obtained had a fluorine content of 3.4% by weight and an alcoholic hydroxyl content of 7.0% by weight. Phantom weight%, ammonium ion content 1.6% by weight, porosity 0.87/8
The specific surface area was 65 g and the average particle size was 40 microns. This carrier was impregnated with titanium tetrachloride as shown in Example 1, resulting in a fluorine content of 4.15% by weight, an alcoholic hydroxyl content of 2.7% by weight, a titanium content of 2.0% by weight, and an ammonium ion content. 2.5% by weight of catalyst component was obtained.

This catalyst component 10 and triethylaluminum 1'
Ethylene was polymerized under the conditions shown in Example 1 using

After 2 hours of polymerization, the following properties: Melt index
0.7 density
48 polyethylene females with 0.96 g/skin were obtained.

The productivity and activity of the catalyst is expressed in the above units as 240
00g and 1200k9.

Example 8 Three portions of powdered anhydrous magnesium chloride with an average particle size of 60 microns were mixed with 3 grams of ammonium fluoride under dry conditions.

100' of n-dodecane was added to the resulting mixture.
The temperature was maintained at about 20 oo and a pressure of 0.5 k9/c flow was applied with nitrogen. A solution containing 90 ml of n-dodecane and 10 ml of ethyl alcohol was added slowly over a 2 hour period. The entire addition was kept under low pressure. At the end of the addition, the whole was left at ambient temperature for 1 hour and then heated under pressure at 110 qC for 1 hour. After separating n-dodecane, it has the following properties: alcoholic hydroxyl group content 7.2% by weight, fluorine content 3.6% by weight, ammonium ion content 3% by weight, porosity 0.65/g and specific surface area 50%. /g
A carrier with .

This support was prepared by dissolving a stoichiometric amount of titanium tetrachloride in hebutane.
Impregnation was carried out by treatment with 0oo for 6 hours. Thus, the average particle size is 60 microns and the titanium content is 5% by weight.
, alcoholic hydroxyl group content 0. A granular catalyst component was obtained having a fluorine content of 5% by weight and an ammonium ion content of 4.2% by weight.

This catalyst component contains 10 female and 1 triethylaluminum.
Polymerization of ethylene was carried out under the conditions shown in Example 1 using

After 2 hours of polymerization, the following properties: Melt index
0.1 density
55 polyethylene females with a total of 0.093% were obtained.

Claims (1)

[Scope of Claims] 1. A Ziegler catalyst system formed by the combination of an organoaluminum compound and a catalyst component made from titanium tetrachloride supported on a carrier, wherein the carrier combines magnesium chloride with an aliphatic alcohol and a catalyst component made from titanium tetrachloride. an active solid complex obtained by reacting with a fluorine-containing compound at a temperature of about 100°C to about 200°C, the complex comprising a fluorine-containing compound;
~15% by weight and 0.4 alcoholic hydroxyl groups
A Ziegler catalyst system characterized in that it contains ~11% by weight. 2. The Ziegler catalyst system of claim 1, wherein the fluorine-containing compound is selected from hydrogen fluoride, ammonium fluoride, phosphorous fluoride, fluorine, and mixtures thereof. 3. Ziegler catalyst system according to claim 1 or 2, in which the aliphatic alcohol contains 1 to 5 carbon atoms per molecule. 4. The Ziegler catalyst system according to claim 3, wherein the aliphatic alcohol is ethanol. 5 The complex contains 3-10% by weight of fluorine and 4-9% by weight
A Ziegler catalyst system according to any one of claims 1 to 4, comprising an alcoholic hydroxyl group of. 6. The carrier was prepared by contacting magnesium chloride, an aliphatic alcohol and a fluorine-containing compound, optionally in the presence of a liquid diluent, and heating the resulting mixture at a temperature of 100°C to 200°C. A Ziegler catalyst system according to any one of claims 1 to 5. 7. The Ziegler catalyst system according to claim 6, wherein excess aliphatic alcohol is removed by evaporation during heat treatment. 8. The Ziegler catalyst system according to claim 6 or 7, wherein the heat treatment is performed by spray drying. 9
The Ziegler catalyst system according to any one of claims 1 to 8, wherein the reaction is carried out at 120°C to 160°C. 10 The catalyst component is titanium tetrachloride with an active solid complex at 20°C.
A Ziegler catalyst system according to any one of claims 1 to 9, which is prepared by reaction at a temperature of -150<0>C. 11. The Ziegler catalyst system according to any one of claims 1 to 10, wherein the catalyst component has a hydroxyl group content of 0.03 to 5% by weight and a fluorine content of 1 to 14% by weight. 12. The Ziegler catalyst system according to claim 11, wherein the catalyst component has a hydroxyl group content of 0.5 to 4% by weight and a fluorine content of 3 to 8% by weight. 13. The Ziegler catalyst system according to any one of claims 10 to 12, wherein the titanium content of the catalyst component is 0.05 to 15% by weight. 14. Ziegler catalyst system according to claim 13, wherein the titanium content is from 1 to 5% by weight. 15 Claim 1, wherein the molar ratio of the organoaluminum compound and titanium tetrachloride is 50:1 to 1000:1.
The Ziegler catalyst system according to any one of Items 1 to 12. 16 Claim 1, wherein the molar ratio of the organoaluminum compound and titanium tetrachloride is 100:1 to 500:1.
Ziegler catalyst system according to item 5.