JPH072786B2 - Olefin polymerization catalyst - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst which provides a polymer having high activity and good polymer properties.

Conventionally, when a magnesium compound such as magnesium halide, magnesium oxyhalide, dialkyl magnesium, alkyl magnesium halide, magnesium alkoxide, or a complex of dialkyl magnesium and organic aluminum is used as a carrier for a transition metal compound such as a titanium compound, it becomes a highly active catalyst. It is known that many inventions have been proposed.

In these prior arts, although the catalyst activity is high to some extent, the polymer properties of the polymer produced are not sufficient, and improvement is desired. Polymer properties are extremely important in slurry polymerization and gas phase polymerization. If the polymer properties are poor, polymer adhesion in the polymerization tank,
This may cause the polymer to be removed from the polymerization tank.
Further, the polymer concentration in the polymerization tank is closely related to the polymer properties, and unless the polymer properties are good, the polymer concentration in the polymerization tank cannot be increased. The fact that the polymer concentration cannot be increased is a great disadvantage in industrial production.

Further, in the conventional production of many catalyst components, a large amount of the transition metal component is used, and the so-called "transition metal component unit" is poor. This is a great disadvantage in producing the catalyst. Many transition metal components that were not contained as catalyst components need to be removed from the catalyst components, which necessitates many solvents and the like, leading to an increase in the production cost of the catalyst. Further, the unnecessary transition metal component needs to be decomposed, and in that case, halogen gas, hydrogen halide, etc. are often generated, which is extremely bad in terms of environmental hygiene. Therefore, it is desired to improve the basic unit of the transition metal component.

Ziegler type catalysts are well known as catalysts for olefin stereoregular polymerization, and it is also well known that various methods have been proposed in order to further improve the activity and stereoregularity.

Among these various improving methods, the method having a remarkable improving effect on the activity is to introduce a magnesium compound into a solid component (Japanese Patent Publication No. 39-12).
No. 105, JP-B-47-41676, and JP-B-47-46269). However, when olefins such as propylene are polymerized using the catalysts produced by these methods, the activity shows a very high value, but the stereoregularity of the produced polymer is remarkably lowered, and the olefin stereoregularity is decreased. It is also known that practical value as a polymerization catalyst is greatly lost.

Therefore, in the olefin polymerization using a Ziegler type catalyst containing a magnesium compound, various methods for improving the stereoregularity of the produced polymer have been proposed (Japanese Patent Laid-Open No. S60-18753).
47-9842, 50-126590, 51-57789, etc.).

These methods are commonly characterized in that a solid catalyst component containing a titanium compound and a magnesium halogen compound further contains an electron donor such as an ester or an amine.

On the other hand, a method of adding a silicon compound, alcohol or the like as a third additive to the solid catalyst component in addition to the electron donor (Japanese Patent Laid-Open Nos. 50-108385, 52-100596 and 52-104596).
No. gazettes) are also known.

Although such a method significantly improves the stereoregularity of the active polymer and the produced polymer, the decatalysis step of the produced polymer and the extraction step of the amorphous polymer have not yet been eliminated. Also, the properties of the polymer produced are not sufficient.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a solution to the above-mentioned problems, and it is an object of the present invention to achieve this object by a catalyst comprising a combination of specific components. That is, the olefin polymerization catalyst according to the present invention is characterized by comprising a combination of the following components (A) to (C).

Component (A) A contact product of the following components (a) to (c):
A solid composition having a molar ratio of component (b) to titanium of less than 0.1.

Component (a) Catalytic product of magnesium dihalide, titanium tetraalkoxide and / or a polymer thereof and a polymeric silicon compound having the structure shown below. Component (b) Ortho C ₆ H ₄ (COCl) ₂ or cyclo-C ₆ H ₁₀ (COCl)
₂ components (c) At least _one of the following components (c ₁ ) and (c ₂ ).

However, the amount of the component (c ₁ ) used is in the range of 0.1 to 10 in atomic ratio with respect to the magnesium compound constituting the component (a), and the amount of the component (c ₂ ) used is 0.1 to 10 in the atomic ratio. Within the range of 10.

Component (c ₁ ) General formula: TiX ₄ (where X is halogen), Component (c ₂ ) General formula: SiX ₄ (where X is halogen).

Component (B) Organoaluminum compound Component (C) Silicon compound having Si-O-C structure Effect When the solid catalyst according to the present invention is used as a Ziegler catalyst to polymerize an olefin, it is highly active and has excellent polymer properties. A polymer is obtained. For example, considering the polymer bulk specific gravity, which is one measure of polymer properties, 0.40 (g / cc) or more is possible and 0.45 (g / cc) is possible.
It is also possible to make it above. Another advantage of using the solid catalyst component according to the present invention is that the polymerization rate pattern can be controlled. Generally, when polymerization is carried out using a highly active catalyst, there are many decay types in which the activity is high at the beginning of the polymerization and then decreases. Such a decay type is not preferable because the catalyst performance may not be fully obtained depending on the polymerization conditions. When the solid catalyst component according to the present invention is used, the activity at the initial stage of the polymerization can be suppressed and so-called continuous type polymerization can be carried out.

Further, as a feature of the catalyst according to the present invention, the molar ratio of the component (b) to titanium in the component (A) is as small as less than 0.1. To the present inventors' knowledge, it is necessary that a certain amount (about 0.5 to 2 in terms of the above molar ratio) of the electron donor remains in the solid component of the olefin polymerization catalyst component. It was surprising that the present invention was found to provide catalytic performance at much lower amounts than previously required. Further, it was more surprising that the catalytic performance was higher when a small amount or substantially no electron donor was left, as in the present invention, than when a large amount of electron donors were left.

DETAILED DESCRIPTION OF THE INVENTION Component (A) This is the contact product of component (a), component (b) and component (c) below.

Component (a) (1) Composition Component (a) is a fixed composition which is the contact product of magnesium dihalide, titanium tetraalkoxide and / or its polymer, and certain polymeric silicon compounds.

This fixing composition (a) is not a complex of magnesium dihalide with titanium tetraalkoxide and / or its polymer, but another solid. At present, its content has not been sufficiently analyzed, but according to the result of composition analysis, this solid composition contains titanium, magnesium, halogen and silicon.

Component (a) is a contact product of the above three components, but need not consist solely of these three components. Therefore, the molar ratio to the magnesium dihalide constituting the component (a) is 1
Alcohols and / or organic acid esters in the range of x10 ^{-3 to} 5x10 ^-1 can be included and are also preferred.

(2) Production Component (a) is produced by mutual contact of magnesium dihalide, titanium tetraalkoxide and / or its polymer and polymeric silicon compound.

(A) Magnesium dihalide For example, MgF ₂ , MgCl ₂ , MgBr ₂ and the like.

(B) Titanium tetraalkoxide and its polymer titanium tetraalkoxide include, for example, Ti (OC
_{2 H 5) 4, Ti (} O-iC 3 H 7) 4, Ti (O-nC 4 H 9) 4, Ti
_{(O-nC 3 H 7)} 4, Ti (O-iC 4 H 9) 4, Ti [OCH ₂ CH (CH
₃ ) ₂ ] ₄ , Ti [OC (CH ₃ ) ₃ ] ₄ , Ti (O-nC
_{5 H 11) 4, Ti (} O-nC 6 H 13) 4, Ti (O-nC 7 H 15) 4,
Ti [OCH ₂ CH (C ₂ H ₅ ) C ₄ H ₉ ] ₄ and the like. Among these, Ti (OC ₂ H ₅ ) ₄ and Ti (O-nC ₄ H ₉ ) ₄ are preferable.
Is.

As the polymer of titanium tetraalkoxide, those represented by the following formula are suitable.

Here, R _{2 to} R ₅ are the same or different hydrocarbon residues, preferably an aliphatic or aromatic hydrocarbon having 1 to 10 carbon atoms, and particularly an aliphatic hydrocarbon having 2 to 6 carbon atoms. n is a number of 2 or more, particularly up to 20. It is desirable that the value of n be selected so that the polytitanium number ester itself or in the form of a liquid solution can be subjected to the step of contacting with other components.
A value n that is suitable for handling is 2 to 14, preferably 2 to 10. Specific examples of such polytitanate include normal butyl polytitanate, (n = 2-1
0), hexyl polytitanate (n = 2 to 10), normal octyl polytitanate (n = 2 to 10) and the like.
Of these, normal butyl polytitanate is preferred.

(C) Polymer Silicon Compound For this, those represented by the following formula are suitable.

Here, R ¹ is a hydrocarbon residue having about 1 to 10 carbon atoms, particularly about 1 to 6 carbon atoms.

Specific examples of the polymer silicon compound having such a structural unit include methylhydropolysiloxane, ethylhydropolysiloxane, phenylhydropolysiloxane,
Examples thereof include cyclohexylhydroporosilixane.

The degree of polymerization thereof is not particularly limited, but those having a viscosity of about 10 centistokes to 100 centistokes are preferable in consideration of handling. Although the terminal structure of the hydropolysiloxane does not have a great influence, it is preferably blocked with an inert group such as a trialkylsilyl group.

(D) Alcohol and / or ester In addition to these components, a small amount of alcohol and / or organic acid ester can be used as described above.

As the alcohol, a monohydric or dihydric alcohol having about 1 to 20 carbon atoms is suitable. As the ester, an ester of such an alcohol and a monobasic to tribasic aliphatic (including cycloalkyl) or aromatic (including alkaryl) carboxylic acid having 2 to 20 carbon atoms is suitable. .

(E) Contact of Each Component (Amount Ratio) The amount of each component used may be arbitrary as long as the effect of the present invention is recognized, but generally, the following range is preferable.

The amount of titanium tetraalkoxide and / or its polymer to be used is preferably in the range of 0.1 to 10 with respect to magnesium dihalide, preferably in the range of 1 to 4, and more preferably in the range of 2 to 4. Within the range of 3. It is preferable that the dihalogenated magnesium is substantially dissolved in titanium tetraalkoxide and / or its polymer by appropriately selecting the quantitative ratio.

The titanium halide is used in a molar ratio of 0.1 to 5 with respect to titanium tetraalkoxide and / or its polymer.
The range of 0 is preferable, and the range of 1 to 10 is preferable.

When alcohol and / or organic acid ester is used, the amount thereof is preferably in the range of 1 × 10 ^{−3 to} 5 × 10 ⁻¹ in terms of molar ratio to magnesium dihalide, and preferably 5 × 10 ^−2. Within the range of 3 × 10 ^-1 .

(Contact Method) The solid composition (a) of the present invention is obtained by contacting the above-mentioned three to four components. Contact of each component can be carried out by any generally known method. In general,
The contact may be performed within a temperature range of -100 ° C to 200 ° C. The contact time is usually about 10 minutes to 20 hours.

The components are preferably brought into contact with each other with stirring, or they may be brought into contact by mechanical pulverization using a ball mill, a vibration mill, or the like. The order of contact of each component is
As long as the effect of the present invention can be recognized, it can be any, but magnesium dihalide and titanium tetraalkoxide and / or its polymer are first contacted to dissolve the former in the latter, and then a polymeric silicon compound is contacted. It is generally done. The contact of each component can also be performed in the presence of a dispersion medium. In that case, examples of the dispersion medium include hydrocarbons, halogenated hydrocarbons, dialkylsiloxanes and the like. Specific examples of the hydrocarbon include hexane, heptane, toluene, cyclohexane, etc., and specific examples of the halogenated hydrocarbon include n-butyl chloride, 1,2-dichloroethylene, carbon tetrachloride, chlorobenzene, etc. Specific examples of the siloxane include dimethylpolysiloxane and methyl-phenylpolysiloxane.

Component (b) Component (b) is ortho C ₆ H ₄ (COCl) ₂ or cyclo
It is C ₆ H ₁₀ (COCl) ₂ .

Component (c) This is at least _one of the following components (c ₁ ) to (c ₂ ).

The component (c ₁ ) is TiX ₄ (where X is halogen). Specific examples include TiCl ₄ , TiBr ₄ , and the like. Among them, TiCl ₄ is preferable.

The component (c ₂ ) is SiX ₄ (where X is a halogen). Specific examples include SiCl ₄ , SiBr ₄ , and the like. Of these, SiCl ₄ is preferable.

Synthesis of Component (A) Component (A) of the present invention is a solid composition consisting of the contact products of components (a)-(c).

(1) Amount Ratio The amount of each component used is arbitrary as long as the effects of the present invention are recognized, but generally the following ranges are preferable.

The amount of the component (b) used is preferably in the range of 1 × 10 ⁻³ to 10 and preferably in the range of 1 × 10 ⁻² to 1 with respect to the magnesium dihalide constituting the component (a). (Details below). The amount of component (c) used is 0.1 to 10 in terms of atomic ratio with respect to the magnesium dihalide constituting component (a).
The range of is good.

(2) Contact Method The catalyst component (A) of the present invention is obtained by contacting the above-mentioned component (a) with the component (b) and the component (c) at once or stepwise. Contact is generally -100 ° C
It may be carried out within a temperature range of up to 200 ° C.

The contact time is usually about 10 minutes to 20 hours.

The solid component (a) and the components (b) to (c) are preferably contacted with stirring, and a ball mill, a vibration mill,
It is also possible to bring them into contact by mechanically crushing them with the above. The order of contact is as long as the effect of the present invention is recognized.
It can be arbitrary.

The contact between the solid component (a) and the components (b) to (c) is
It can also be carried out in the presence of a dispersion medium. The dispersion medium at that time can be selected from those exemplified as those to be used when producing the component (a).

Content of component (b) According to the invention, the content of component (b) in component (A) is less than 0.1 mol, in particular 0.005 to 0.007 mol, per mol titanium.
Is.

The content of the acid halide (component (b)) in the solid catalyst component (component (A)) of the present invention is adjusted by the conditions of the component (c) treatment, that is, the amount of the component (c) used, the treatment temperature and the time. can do. Generally, the stronger the treatment, the lower the content of component (b).

The component (b) in the component (A) is not necessarily in the form of an acid halogen compound. In the catalyst preparation, component (b)
It is highly possible that the compound has a form other than the acid halogen compound by reacting with or adding to other components.

Specific examples of the component (B) organoaluminum compound include those represented by the general formula:
⁶ _3-n ▼ AlX _n or ▲ R ⁷ _3-m ▼ Al (OR ⁸ ) _m (where R ⁶
And R ⁷ are each a hydrocarbon residue or hydrogen having about 1 to 20 carbon atoms, R ⁸ is the above hydrocarbon residue, X is a halogen, n
And m are the numbers of On <2 and Om1, respectively. ). Specifically, (a) trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum,
Trialkyl aluminum such as trioctyl aluminum and tridecyl aluminum, (b) diethyl aluminum monochloride, diisobutyl aluminum monochloride, ethyl aluminum sesquichloride,
Alkyl aluminum halides such as ethyl aluminum dichloride, (c) diethyl aluminum hydride, dialkyl aluminum hydrides such as diisobutyl aluminum hydride, (d) diethyl aluminum ethoxide, diethyl aluminum butoxide, alkyl aluminum alkoxides such as diethyl aluminum phenoxide, and the like. To be

In addition to these organoaluminum compounds (a) to (c), other organometallic compounds such as ▲ R ⁹ _3-a ▼ Al (OR ¹⁰ ) _a (1
a3, R ⁹ and R ¹⁰ are the same or different hydrocarbon residues having about 1 to 20 carbon atoms. It is also possible to use an alkylaluminum alkoxide represented by the formula (1). For example, combined use of triethylaluminum and diethylaluminum ethoxide, combined use of diethylaluminum monochloride and diethyl-aluminum ethoxide, combined use of ethylaluminum dichloride and ethylaluminum diethoxide, triethylaluminum, diethylaluminum ethoxide and diethylaluminum. It can be used in combination with chloride.

The amount of these organometallic compounds used is not particularly limited,
The weight ratio with respect to the solid catalyst component of the present invention is preferably within the range of 0.5 to 1000.

Any silicon compound having a component (C) Si-O-C structure can be used.

A group that should satisfy the remaining valences of Si and C has 1 carbon atom.
Approximately about 20 aliphatic (including cycloalkyl) or aromatic (including alkaryl) hydrocarbon residues or hydrocarbon-oxygen residues (including acyl groups) and the like are suitable.

Specific examples of such compounds include methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, and phenyltriethoxysilane. , Diphenyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, chlorotriethoxysilane, acetoxytriethoxysilane, tetramethoxysilane, tetraethoxysilane and the like.

The amount of the component (C) used is the organoaluminum compound (B)
It is 0.01-1.0 mol, preferably 0.05-0.5 mol, per 1 mol.

Preparation of Catalyst The catalyst according to the present invention is formed by bringing the components (A) to (C) into contact with each other either temporarily or stepwise.

Olefin Polymerization Olefin The olefin polymerized with the catalyst system of the present invention has the general formula R-CH
= CH ₂ (wherein R is a hydrocarbon residue having 1 to 10 hydrogen atoms or carbon atoms, and may have a branched group). Is represented by. Specifically, ethylene, propylene,
There are olefins such as butene-1, pentene-1, hexene-1, 4-methylpentene-1. Preferably,
Ethylene and propylene. In the case of these polymerizations, copolymerizations with up to 50% by weight, preferably 20% by weight, with respect to ethylene can be carried out, up to 30% by weight with respect to propylene, in particular with ethylene. Can be copolymerized with. Copolymerization with other copolymerizable monomers (for example, vinyl acetate, diolefin) can also be performed.

Polymerization The catalyst system of the present invention is applied not only to ordinary slurry polymerization, but also to liquid phase solventless polymerization, solution polymerization, or gas phase polymerization method which uses substantially no solvent. Further, it is also applied to a system in which continuous polymerization, batch polymerization or preliminary polymerization is carried out. As the polymerization solvent in the case of slurry polymerization, saturated aliphatic or aromatic hydrocarbons such as hexane, heptane, pentane, cyclohexane, benzene, and toluene may be used alone or as a mixture. The polymerization temperature is from room temperature to about 200 ° C., preferably 50 ° C. to 150 ° C., and hydrogen can be supplementarily used as a molecular weight regulator at that time.

Experimental Examples Example-1 Synthesis of Component (a) n was dehydrated and deoxygenated in a flask that had been sufficiently replaced with nitrogen.
-Introduce 75 ml of heptane, then add 0.1 ml of MgCl ₂ .
0.2 mol of Ti (O-nC ₄ H ₉ ) ₄ was introduced, and 2
Reacted for hours. After the reaction was completed, the temperature was lowered to 40 ° C., 15 ml of methylhydrogen polysiloxane was introduced, and the reaction was carried out for 3 hours. After completion of the reaction, the produced solid component was washed with n-heptane, and a part thereof was taken out and analyzed for composition. Ti = 15.6% by weight,
Mg = 4.3 weight percent.

Synthesis of component (A) A flask that had been sufficiently replaced with nitrogen was dehydrated and deoxygenated.
-100 ml of heptane was introduced, and 0.03 mol of the component (a) synthesized above was introduced in terms of Mg atom. SiCl ₄
0.05 mol was introduced at 30 ° C. for 1 hour and reacted at 90 ° C. for 4 hours. After completion of the reaction, it was washed with purified n-heptane.
Then add 25 ml of n-heptane to Ortho C ₆ H.
0.004 mol of ₄ (COCl) ₂ was mixed, introduced at 70 ° C. for 1 hour, and reacted at 70 ° C. for 1 hour. After completion of the reaction, purified n
-Washed with heptane. Then, 25 ml of TiCl ₄ was introduced and reacted at 100 ° C. for 6 hours. After the reaction,
It was washed with n-heptane to obtain a catalyst component. Ti content is 2.
It was 31 weight percent and the molar ratio of component (b) to titanium in the catalyst was 0.07.

Polymerization of Propylene 500 ml of fully dehydrated and deoxygenated n-heptane, 125 mg of triethylaluminum (B), diphenyldimethoxysilane (C) Milligram and 10 milligram of solid composition (A) synthesized above were introduced. Then
Introduce 60 ml of H ₂ , raise temperature and pressure, polymerization pressure = 5 k
Polymerization was carried out under the conditions of g / cm ² G, polymerization temperature = 75 ° C. and polymerization time = 2 hours. After the polymerization was completed, the obtained polymer slurry was separated by filtration and the polymer was dried.

187.4 grams of polymer were obtained. On the other hand, from excess fluid
0.8 gram of polymer was obtained. From the boiling heptane extraction test, the total product II (hereinafter abbreviated as T-1.I) was 98.4 weight percent. The MFR was 4.1 (g / 10 min) and the bulk density of the polymer was 0.435 (g / cc).

Example-2 Synthesis of Component (A) In the same manner as in Example-1, the component (a) was introduced into a 0.03 mol flask in terms of Mg atom. 0.05 mol of SiCl ₄ was introduced at 30 ° C. for 2 hours and reacted at 90 ° C. for 5 hours. After completion of the reaction, it was washed with purified n-heptane. Then, 25 ml of n-heptane was mixed with 0.003 mol of ortho-C ₆ H ₄ (COCl) ₂ and the mixture was introduced at 70 ° C. and reacted for 5 minutes. After completion of the reaction, it was washed with purified n-heptane. Then, 25 ml of TiCl ₄ was introduced and reacted at 110 ° C. for 6 hours. After completion of the reaction, it was washed with n-heptane to obtain a catalyst component. Ti
The content was 2.22 weight percent and the molar ratio of component (b) to titanium in the catalyst was 0.01.

Polymerization of Propylene Polymerization was carried out in the same manner as in Example-1, except that 25 mg of phenyltriethoxysilane (C) was used instead of diphenyldimethoxysilane (C).

171.6 grams of polymer were obtained. T-II = 97.8 weight percent, MFR = 3.7 (g / 10 min), polymer bulk ratio polymerization =
It was 0.43 (g / cc).

Example-3 Production of Component (A) In the production of Component (A) of Example-2, Ortho-C ₆ H ₄
Except for using cyclo C ₆ H ₁₀ (COCl) ₂ in place of (COCl) ₂ was conducted in exactly the same way as in manufacturing. The Ti content was 2.41 weight percent, and the amount ratio of component (b) to titanium was 0.06.

Polymerization of propylene Under the polymerization conditions of Example-1, propylene was polymerized in exactly the same manner except that phenyltrimethoxysilane (C) was used instead of diphenyldimethoxysilane (C).

102.6 grams of polymer were obtained. MFR = 5.2 (g / 10
Min), T-II = 95.6 weight percent, and polymer bulk specific gravity = 0.43 (g / cc).

Comparative Example-1 Synthesis of Component (A) In the same manner as in Example-1, the component (a) was introduced into a 0.03 mol flask in terms of Mg atom. 0.05 mol of SiCl ₄ was introduced at 30 ° C. for 15 minutes and reacted at 50 ° C. for 1 hour. After completion of the reaction, it was washed with purified n-heptane. Then, 25 ml of n-heptane was mixed with 0.004 mol of ortho C ₆ H ₄ (COCl) ₂ and the mixture was introduced at 70 ° C. and reacted at 90 ° C. for 2 hours. After completion of the reaction, it was washed with purified n-heptane. Then TiCl ₄ 2
5 ml was introduced and the reaction was carried out at 70 ° C. for 3 hours. After completion of the reaction, it was washed with n-heptane to obtain a catalyst component.
The Ti content was 2.86 weight percent and the molar ratio of component (b) to titanium in the catalyst was 0.82.

Polymerization of Propylene Polymerization was carried out under the same conditions as in Example-1. 131.5
Grams of polymer were obtained. T-II = 98.1 weight percent, MFR = 4.3 (g / 10 min), polymer bulk specific gravity = 0.44
(G / cc).

Comparative Examples-2 to 6 Synthesis of Component (A) and Polymerization of Propylene Table 1 instead of ortho C ₆ H ₄ (COCl) ₂ as the component (b) in the synthesis of the component (A) of Example-2. Synthesis was performed in exactly the same manner except that the compound was used. Further, in the polymerization of propylene of Example-2, propylene was polymerized in exactly the same manner except that the compound shown in the table was used as the component (C). The results are shown in Table-1.

In the synthesis of component (A) of Example -4 Example -1, instead of TiCl ₄ 25 ml except using SiCl ₄ 17 milliliters synthesis and the component (A component of Example -1 (a) ) Was synthesized to obtain the component (A). Polymerization of propylene was carried out in the same manner as in Example-1 except that the obtained component (A) was used. The result was 154.5 grams of polymer, TI.I. = 98.5 weight percent, MFR = 3.8 (g /
10 minutes), and the bulk density of the polymer was 0.44 (g / cc).

[Brief description of drawings]

FIG. 1 is intended to help the understanding of the technical content of the present invention regarding the Ziegler catalyst.

Claims (1)

[Claims] 1. An olefin polymerization catalyst comprising a combination of the following components (A) to (C). Component (A) A contacting product of the following components (a) to (c):
Solid composition having a molar ratio of component (b) to titanium of less than 0.1, component (a) magnesium dihalide, titanium tetraalkoxide and / or polymer thereof and polymeric silicon compound having a structure represented by the following formula Contact products of Component (b) Ortho C ₆ H ₄ (COCl) ₂ or cyclo-C ₆ H ₁₀ (COCl)
₂ , component (c) At least _one of the following components (c ₁ ) and (c ₂ ), provided that the amount of (c ₁ ) used is 0.1 to 10 in atomic ratio with respect to the magnesium compound constituting component (a). Within the range, the amount of the component (c ₂ ) used is within the range of 0.1 to 10 in terms of the atomic ratio, component (c ₁ ): TiX ₄ (where X is halogen), component (c ₂ ): SiX ₄ (Where X is halogen), component (B) organoaluminum compound, component (C) silicon compound having Si—O—C bond.