JP2851886B2 - Olefin polymerization catalyst and olefin polymerization method using the catalyst - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a catalyst for olefin polymerization and a method for polymerizing olefins using the catalyst. More specifically, the present invention relates to a method for polymerizing olefins by slurry polymerization or gas phase polymerization, particularly gas phase polymerization. In this case, the present invention relates to an olefin polymerization catalyst capable of obtaining a granular or spherical olefin polymer having a good particle size distribution and an excellent bulk specific gravity, and a method for polymerizing an olefin using the catalyst.

Technical Background of the Invention There have already been many proposals for a method for producing a solid titanium catalyst component containing magnesium, titanium and halogen as essential components. Such a solid titanium catalyst component and a group I to group III of the periodic table have been proposed. It is known that an olefin polymerization catalyst comprising a metal organometallic compound component exhibits excellent polymerization activity for olefins. However, it is desired that such an olefin polymerization catalyst be further improved in terms of polymerization activity or the powder properties of the resulting polymer, especially the olefin copolymer.

For example, in order to obtain a high quality olefin polymer without decatalyzing operation after polymerization, it is necessary to sufficiently increase the polymer yield per unit weight of titanium or halogen.
When the olefin polymer is obtained by slurry polymerization or gas phase polymerization, the polymerization operation and the separation and transportation of the polymer,
It is necessary to smoothly and efficiently perform post-treatment operations such as granulation. For this reason, the obtained polymer needs to be excellent in particle size distribution, fluidity, bulk specific gravity, and the like, and also excellent in fracture resistance. Furthermore, in order to omit the usual pelletization after polymerization and supply the powder as it is to the market, produce an olefin polymer having a small particle size and a large particle size with a uniform shape and particle size distribution. There is a need. From such a viewpoint, conventionally known olefin polymerization catalysts are particularly desired to be further improved when producing an olefin copolymer.

Japanese Patent Laid-Open No. 57-10609 discloses a catalyst comprising a solid titanium catalyst component containing magnesium, titanium and halogen as essential components and an organometallic compound catalyst component of a Group I to Group III metal of the periodic table. A method for producing an ethylene polymer, which is characterized by main-polymerizing ethylene after pre-polymerizing an olefin, is disclosed.According to this method, an ethylene polymer having a significantly improved particle size distribution and bulk specific gravity is disclosed. can get. However, there has been a demand for an olefin polymerization catalyst capable of obtaining a granular or spherical olefin polymer, particularly an ethylene polymer, which has a better particle size distribution and an excellent bulk specific gravity.

Object of the Invention The present invention has been made in view of the prior art as described above, and provides a granular or spherical olefin polymer, particularly an ethylene polymer, having a good particle size distribution and excellent bulk specific gravity. It is an object of the present invention to provide an olefin polymerization catalyst capable of producing the olefin polymerization and a method for polymerizing an olefin using the olefin polymerization catalyst.

SUMMARY OF THE INVENTION The olefin polymerization catalyst according to the present invention comprises: [A] a solid titanium catalyst component [A-1] containing magnesium, titanium, halogen and, if necessary, an electron donor as essential components; [I] or [II]
A solid catalyst component obtained by contacting with an organoaluminum compound [A-2] having an Al—O bond represented by the following formula: [B] an organoaluminum compound catalyst component, and, if necessary, [C] an electron donor. It is characterized by being formed from.

The olefin polymerization method according to the present invention is characterized in that olefin is polymerized or copolymerized in the presence of the olefin polymerization catalyst as described above.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the catalyst for olefin polymerization according to the present invention and a method for polymerizing olefins using the catalyst will be specifically described.

In the present invention, the term polymerization is used not only for homopolymerization but also for meaning including copolymerization,
In addition, the term polymer is sometimes used to mean not only a homopolymer but also a copolymer.

FIG. 1 is a flow chart illustrating the process for preparing the olefin polymerization catalyst according to the present invention.

The catalyst for olefin polymerization according to the present invention comprises: [A] a solid titanium catalyst component [A-1] containing magnesium, titanium and halogen and, if necessary, an electron donor as essential components, and the following general formula [I] or An organoaluminum compound having an Al—O bond represented by [II] [A-
2], [B] an organoaluminum compound catalyst component, and if necessary, [C] an electron donor.

First, the solid titanium catalyst component [A-1] will be described.

Such a solid titanium catalyst component [A-1] is prepared by contacting the following magnesium compound, titanium compound and, if necessary, an electron donor.

In the present invention, the titanium compound used for preparing the solid titanium catalyst component [A-1] includes, for example, Ti
(OR) _g X _4-g (R is a hydrocarbon group, X is a halogen atom, 0
.Ltoreq.g.ltoreq.4). More specifically, titanium tetrahalides such as TiCl ₄ , TiBr ₄ , and TiI ₄ ; Ti (OCH ₃ ) Cl ₃ , Ti (OC ₂ H ₅ ) Cl ₃ , Ti (On-C ₄ H ₉ ) Cl ₃ , Ti (OC ₂ H ₅ ) Br ₃ , Ti (OisoC ₄ H ₉ ) Br _3, etc .; trihalogenated alkoxytitanium; Ti (OCH ₃ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ ) ₂ Cl ₂ , Ti ( _{On-C 4 H 9) 2} Cl 2, Ti (OC 2 H 5) 2 dihalogenated dialkoxy titanium, such as _{Br 2; Ti (OCH 3)} 3 Cl, Ti (OC 2 H 5) 3 Cl, Ti (On Monohalogenated trialkoxy titanium such as -C ₄ H ₉ ) ₃ Cl, Ti (OC ₂ H ₅ ) ₃ Br; Ti (OCH ₃ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Ti (On-C ₄ H) _{9) 4 Ti (Oiso-C} 4 H 9) 4 Ti (O-2- _ethylhexyl) such as tetra-alkoxy titanium such as ₄ can be cited.

Among these, a halogen-containing titanium compound, particularly a titanium tetrahalide, is preferable, and titanium tetrachloride is more preferably used. These titanium compounds may be used alone or in combination of two or more. Further, these titanium compounds may be diluted with a hydrocarbon compound or a halogenated hydrocarbon compound.

In the present invention, examples of the magnesium compound used for preparing the solid titanium catalyst component [A-1] include a reducing magnesium compound and a non-reducing magnesium compound.

Here, examples of the magnesium compound having a reducing property include a magnesium compound having a magnesium-carbon bond or a magnesium-hydrogen bond. Specific examples of such a reducing magnesium compound include dimethylmagnesium, diethylmagnesium, dipropylmagnesium, dibutylmagnesium, diamilmagnesium, dihexylmagnesium, didecylmagnesium, ethylmagnesiumchloride, propylmagnesiumchloride, butyl Examples thereof include magnesium chloride, hexyl magnesium chloride, amyl magnesium chloride, butylethoxymagnesium, ethylbutylmagnesium, octylbutylmagnesium, and butylmagnesium hydride. These magnesium compounds can be used alone or may form a complex compound with an organic aluminum compound described later. These magnesium compounds may be liquid or solid.

Specific examples of non-reducing magnesium compounds include magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide, and magnesium fluoride; methoxy magnesium chloride, ethoxy magnesium chloride, isopropoxy magnesium chloride, butoxy chloride. Alkoxy magnesium halides such as magnesium and octoxy magnesium chloride; alkoxy magnesium halides such as phenoxy magnesium chloride and methylphenoxy magnesium chloride; alkoxy such as ethoxy magnesium, isopropoxy magnesium, butoxy magnesium, n-octoxy magnesium and 2-ethylhexoxy magnesium Magnesium; allyloximers such as phenoxymagnesium and dimethylphenoxymagnesium Neshiumu; magnesium laurate, such as carboxylic acid salts of magnesium such as magnesium stearate and the like.

The non-reducing magnesium compound may be a compound derived from the above-described reducing magnesium compound or a compound derived during the preparation of the catalyst component. In order to derive a non-reducing magnesium compound from a reducing magnesium compound, for example, a reducing magnesium compound is converted to a polysiloxane compound, a halogen-containing silane compound, a halogen-containing aluminum compound, an ester, an alcohol, or the like. What is necessary is just to contact with a compound.

In the present invention, the magnesium compound, in addition to the magnesium compound having a reducing property and the magnesium compound having no reducing property, a complex compound of the magnesium compound and another metal, a double compound or another metal compound. May be used. Further, a mixture of two or more of the above compounds may be used.

In the present invention, among these, a magnesium compound having no reducing property is preferable, and a halogen-containing magnesium compound is particularly preferable. Among these, magnesium chloride, alkoxymagnesium chloride, and allyloxymagnesium chloride are preferably used.

In the present invention, in preparing the solid titanium catalyst component [A-1], it is preferable to use an electron donor, and examples of the electron donor include an organic carboxylic acid ester, preferably a polyvalent carboxylic acid ester. Is a compound having a skeleton represented by the following formula.

In the above formula, R ¹ represents a substituted or unsubstituted hydrocarbon group, R ² , R ⁵ , and R ⁶ represent a hydrogen atom, a substituted or unsubstituted hydrocarbon group, and R ³ and R ⁴ represent a hydrogen atom Represents a substituted or unsubstituted hydrocarbon group. Preferably, at least one of R ³ and R ⁴ is a substituted or unsubstituted hydrocarbon group. R ³ and R ⁴ may be connected to each other to form a cyclic structure. Examples of the substituted hydrocarbon group include N,
O, there are mentioned hydrocarbon group substituted containing a hetero atom such as S, for example, -C-O-C -, - COOR, -COOH, -OH, -SO 3 H, -C
-N-C -, - and hydrocarbon group substituted with a structure such as NH _2.

Among these, a diester in which at least one of R ¹ and R ² is derived from a dicarboxylic acid having an alkyl group having 2 or more carbon atoms is preferable.

Specific examples of the polyvalent carboxylic acid ester include diethyl succinate, dibutyl succinate, diethyl methyl succinate, diisobutyl α-methylglutarate, dibutyl methyl malonate, diethyl malonate, diethyl ethyl malonate, diethyl isopropyl malonate, butyl Diethyl malonate, diethyl phenylmalonate, diethyl diethylmalonate, diethyl allylmalonate, diethyldiisobutylmalonate, diethyldinormalbutylmalonate, dimethyl maleate, monooctyl maleate,
Diisooctyl maleate, diisobutyl maleate,
Diisobutyl butyl maleate, diethyl butyl maleate, diisopropyl β-methylglutarate, diallyl ethyl succinate, di-2-ethylhexyl fumarate,
Aliphatic polycarboxylates such as diethyl itaconate, diisobutyl itaconate, diisooctyl citrate, dimethyl citrate; diethyl 1,2-cyclohexanecarboxylate, diisobutyl 1,2-cyclohexanecarboxylate, diethyl tetrahydrophthalate, nadic acid Aliphatic polycarboxylic acid esters such as diethyl; monoethyl phthalate, dimethyl phthalate, methyl ethyl phthalate, monoisobutyl phthalate, diethyl phthalate, ethyl isobutyl phthalate, mononormal butyl phthalate, ethyl normal butyl phthalate, phthalate Acid di n
-Propyl, diisopropyl phthalate, di-n-phthalate
Butyl, diisobutyl phthalate, di-n-heptyl phthalate, di-2-ethylhexyl phthalate, didecyl phthalate, benzyl butyl phthalate, diphenyl phthalate, diethyl naphthalene dicarboxylate, dibutyl naphthalene dicarboxylate, triethyl trimellitate, triethyl Aromatic polycarboxylic acid esters such as dibutyl melitate; esters derived from heterocyclic polycarboxylic acids such as 3,4-furadicarboxylic acid;

Other examples of polycarboxylic acid esters include long-chain dicarboxylic acids such as diethyl adipate, diisobutyl adipate, diisopropyl sebacate, di-n-butyl sebacate, n-octyl sebacate, and di-2-ethylhexyl sebacate. Esters derived from acids can be mentioned.

Among these polyvalent carboxylic acid esters, compounds having a skeleton represented by the aforementioned general formula are preferable, and more preferably phthalic acid, maleic acid, substituted malonic acid, and the like, and alcohols having 2 or more carbon atoms. Esters are preferred, and diesters obtained by reacting phthalic acid with alcohols having 2 or more carbon atoms are particularly preferred.

As these polycarboxylic acid esters, it is not always necessary to use the above-described polycarboxylic acid esters as starting materials, and the solid titanium catalyst component [A-1]
The compound capable of deriving the polycarboxylic acid ester in the preparation process of the above may be used to generate the polycarboxylic acid ester in the step of preparing the solid titanium catalyst component [A-1].

In the present invention, the electron donor other than the polyvalent carboxylic acid that can be used when preparing the solid titanium-based catalyst [A-1] may be used at the time of preliminary polymerization or at the time of main polymerization as described below. Alcohols, amines, amides, ethers, ketones, nitriles, phosphines, stippines, arsines, phosphoramides, esters, thioethers, thioesters, acid anhydrides, acid halides, aldehydes , Alcoholates, organosilicon compounds such as alkoxy (aryloxy) silanes, organic acids, and amides and salts of metals belonging to Groups I to IV of the periodic table.

In the present invention, the solid titanium catalyst component [A-1]
Can be produced by contacting a magnesium compound (or metallic magnesium) as described above, a titanium compound and, if necessary, an electron donor.
In order to produce the solid titanium catalyst component [A-1], a known method for preparing a highly active titanium catalyst component from a magnesium compound, a titanium compound and, if necessary, an electron donor can be employed. The above-mentioned components may be catalyzed in the presence of another reaction reagent such as silicon, phosphorus and aluminum.

The method for producing the solid titanium catalyst component [A-1] will be briefly described below with reference to several columns.

The solid titanium catalyst component [A-1] described below
In the production method described above, an example in which an electron donor is used will be described, but this electron donor does not necessarily have to be used.

(1) A method of reacting a magnesium compound or a complex compound comprising a magnesium compound and an electron donor with a titanium compound in a solid phase. This reaction may be performed in the presence of a grinding aid or the like. Further, when reacting as described above, the solid compound may be pulverized. Furthermore, when reacting as described above, each component may be pretreated with an electron donor and / or a reaction assistant such as an organoaluminum compound or a halogen-containing silicon compound. In this method, the electron donor is used at least once.

(2) a liquid magnesium compound having no reducing property;
A method in which a liquid titanium compound is reacted in the presence of an electron donor to precipitate a solid titanium complex.

(3) A method in which a titanium compound is further reacted with the reaction product obtained in (2).

(4) The reaction product obtained in (1) or (2)
A method in which an electron donor and a titanium compound are further reacted.

(5) A solid obtained by pulverizing a magnesium compound or a complex compound comprising a magnesium compound and an electron donor in the presence of a titanium compound is treated with any of a halogen, a halogen compound and an aromatic hydrocarbon. Method. In this method, a magnesium compound or a complex compound comprising a magnesium compound and an electron donor may be ground in the presence of a grinding aid or the like. Alternatively, a magnesium compound or a complex compound composed of a magnesium compound and an electron donor may be ground in the presence of a titanium compound, pre-treated with a reaction aid, and then treated with a halogen or the like. In addition, examples of the reaction assistant include an organic aluminum compound and a halogen-containing silicon compound. In this method, an electron donor is used at least once.

(6) A method of treating the compound obtained in the above (1) to (4) with a halogen, a halogen compound or an aromatic hydrocarbon.

(7) A method of contacting a reaction product of a metal oxide, dihydrocarbylmagnesium and a halogen-containing alcohol with an electron donor and a titanium compound.

(8) A method in which a magnesium compound such as a magnesium salt of an organic acid, alkoxymagnesium, or aryloxymagnesium is reacted with an electron donor, a titanium compound and / or a halogen-containing hydrocarbon.

(9) magnesium compound and alkoxytitanium and / or
Or a method in which a catalyst component in a hydrocarbon solution containing at least an electron donor such as an alcohol or an ether is reacted with a halogen-containing compound such as a titanium compound and / or a halogen-containing silicon compound. A method in which an electron donor represented by a phthalic acid diester as described above coexists.

Among the methods for preparing the solid titanium catalyst component [A] described in the above (1) to (9), a method using a liquid titanium halide during the catalyst preparation, a method using a titanium compound, or a method using a titanium compound When used, a method using a halogenated hydrocarbon is preferred.

The amount of each of the above components used in preparing the solid titanium catalyst component [A] varies depending on the preparation method and cannot be specified unconditionally. In an amount of 5 moles, preferably 0.05-2 moles, the titanium compound is about 0.01-500
It is preferably used in an amount of 0.05 to 300 moles.

The solid titanium catalyst component [A-
1] contains magnesium, titanium and halogen and, if necessary, an electron donor as essential components.

In this solid titanium catalyst component [A-1], halogen / titanium (atomic ratio) is about 4 to 200, preferably about 5 to 200.
And the electron donor / titanium (molar ratio) is about
0.1 to 10, preferably about 0.2 to about 6, and magnesium / titanium (atomic ratio) is about 1 to 100, preferably about 2 to 50.
It is desirable that

This solid titanium catalyst component [A-1] contains a magnesium halide having a small crystal size as compared with a commercially available magnesium halide, and usually has a specific surface area of about 50%.
m ² / g or more, preferably about 60~1000m ² / g, more preferably from about 100~800m ² / g. The solid titanium catalyst component [A-1] does not substantially change its composition by washing with hexane since the above components are combined to form a catalyst component.

For a method of preparing such a highly active titanium catalyst component, see, for example, JP-A-50-108385 and JP-A-50-126590.
No. 51-20297, No. 51-28189, No. 51
No. 64586, No. 51-92885, No. 51-136625, No. 52-87489, No. 52-100596, No. 52-1
No. 47688, No. 52-104593, No. 53-2580, No. 53-40093, No. 53-40094, No. 53-43
No. 094, No. 55-135102, No. 55-135103, No. 55-152710, No. 56-811, No. 56-119
No. 08, No. 56-18606, No. 58-83006,
JP-A-58-138705, JP-A-58-138706, JP-A-58-138707
JP-A-58-138708, JP-A-58-138709,
Nos. 58-138710, 58-138715, 60-23404
No. 61-21109, No. 61-37802, No. 61
-37803, and the like.

In the present invention, the solid catalyst component [A] is brought into contact with the organoaluminum compound [A-2] having an Al-O bond by contacting the solid titanium catalyst component [A-1] prepared as described above. We are preparing.

Organoaluminum compound having Al-O bond [A-
The _{^{2], R 10 n Al (}} OR 11) m X 3-nm ...... [I] or ^{_{R 10 n Al (OCOR 11)}} m X 3-nm ... [II] [ wherein, R ¹⁰ is the number of carbon atoms A hydrocarbon group having 1 to 10 carbon atoms, and R ¹¹ is a hydrocarbon group having 1 to 20 carbon atoms or SiR ₃ ¹² (wherein
R ¹² is a hydrocarbon group having 1 to 10 carbon atoms), X is halogen or hydrogen, m ≧ 1, and n is 1 or 2. An organoaluminum compound represented by the following formula is used.

As the organoaluminum compound having an Al—O bond represented by the formula [I] or [II], specifically, the following compounds are used.

Dimethyl aluminum methoxide, dimethyl aluminum ethoxide, dimethyl aluminum butoxide, dimethyl aluminum 2-ethyl hexoxide, diethyl aluminum ethoxide, diethyl aluminum butoxide, diethyl aluminum 2-ethyl hexoxide,
Dialkylaluminum alkoxides such as diisobutylaluminum methoxide, diisobutylaluminum ethoxide and dioctylaluminum ethoxide; alkylaluminum dialkoxides such as ethylaluminum diethoxide and isobutylaluminum dibutoxide; dialkylaluminum aryloxy such as diethylaluminum phenoxide and diisobutylaluminum phenoxide , Alkyl aluminum alkoxy halides such as ethyl aluminum ethoxy chloride, isobutyl aluminum ethoxy chloride, alkyl aluminum alkoxy hydrides such as ethyl aluminum ethoxy hydride, isobutyl aluminum butoxy hydride, aluminum acetate diethyl, aluminum propionate Aluminum dialkyl carboxylate such as mudiisobutyl and aluminum diethyl stearate, aluminum alkyl carboxylate such as aluminum acetate ethyl chloride and aluminum isobutyl chloride propionate, trimethylsilaneoxyaluminum diethyl, trimethylsilaneoxyaluminum diisobutyl, triphenylsilaneoxyaluminum diethyl Alkylsilaneoxyaluminum alkyl halides such as alkylsilaneoxyaluminum dialkyl, trimethylsilaneoxyaluminum ethyl chloride, triphenylsilaneoxyaluminum isobutyl chloride;

Of these, dialkyl aluminum alkoxides,
Dialkylaluminum aryloxide and alkylsilaneoxyaluminumdialkyl are preferred, and dialkylaluminum alkoxide is particularly preferred.

The contact between the solid titanium catalyst component [A-1] and the organoaluminum compound [A-2] having an Al-O bond may be specifically performed as follows.

(1) A method in which the catalyst component [A-1] is suspended in a hydrocarbon solvent, and an organoaluminum compound [A-2] is added thereto.

(2) A method of adding a catalyst component [A-1] to a hydrocarbon solvent of an organoaluminum compound [A-2].

 Of these, the method (1) is preferred.

At this time, the concentration of the catalyst component [A-1] in the reaction system is usually 0.1 to 100 mg atom /
, Preferably 0.5 to 50 mg atom /, and the concentration of the organoaluminum compound [A-2] is 0.5 to 1000 mmol /, preferably 1 to 500 mmol /,
The ratio of aluminum atoms to titanium atoms is 0.5-100,
Preferably it is 1-50.

The reaction temperature is usually −50 to 150 ° C., preferably −30 to 100 ° C.
The reaction time is usually 0.2 to 20 hours, preferably 0.5 to 10
About an hour.

Further, in the present invention, as the organoaluminum compound [A-2] having an Al-O bond, a compound capable of producing the above-described organoaluminum compound in a reaction system may be used. Specifically, for example, in a reaction system, an organic compound that generates an organoaluminum compound having an Al—O bond exemplified above by a reaction such as R ₃ ¹³ Al + R ¹⁴ OH → R ₂ ¹³ AlOR ¹⁴ is used. Can also.

Examples of the organometallic compound catalyst component [B] of the Group I to Group III metals of the periodic table include (i) R ¹ _m Al (OR ² ) _n H _p X _q (where R ¹ and R ² are A hydrocarbon group containing usually 1 to 15, preferably 1 to 4 carbon atoms, which may be the same or different, and X represents a halogen atom;
<M ≦ 3, n is 0 ≦ n <3, p is 0 ≦ p <3, and q is 0 ≦
A number of q <3, moreover organic aluminum compound represented by m + n + p + q = a 3), a _{^{(ii) M 1 AlR 1 4}} ( wherein, M ¹ is Li, Na, K, R ¹ is the (Iii) R ¹ R ² M ² (wherein R ¹ and R ² are the same as above. M ² is Mg, Zn or A dialkyl compound of Group II or Group III represented by Cd) is used.

As the organoaluminum compound belonging to the above (i), the following compounds can be exemplified.

General formula R ¹ _m Al (OR ² ) _3-m (wherein R ¹ and R ² are the same as above. M is preferably 1.
A general formula R ¹ _m AlX _3-m (where R ¹ is the same as above; X is a halogen, and m is preferably 0 <m <3); R ¹ _m AlH _3-m (wherein R ¹ is the same as above. M is preferably 2 ≦ m <3
In a), the general formula _{^{R 1 m Al (OR 2)}} n X q ( wherein, R ¹ and R ² are the same .X said halogen, 0
<M ≦ 3, 0 ≦ n <3, 0 ≦ q <3, and m + n + q = 3
And the like.

As the aluminum compound belonging to (i), more specifically, trialkylaluminum such as trimethylaluminum, triethylaluminum, tributylaluminum; trialkenylaluminum such as triisoprenylaluminum; diethylaluminum ethoxide, dibutylaluminum butoxide and the like dialkylaluminum alkoxide; ethylaluminum sesquichloride ethoxide, butyl aluminum sesqui Bed alkylaluminum sesqui alkoxides such _{^{butoxide, R 1 2.5 Al (OR 2}} ) partially alkoxylated alkyl aluminum having an average composition represented by like _0.5; diethylaluminum Dialkylaluminum halides such as chloride, dibutylaluminum chloride and diethylaluminum bromide Alkyl aluminum sesquihalides such as ethylaluminum sesquichloride, butylaluminum sesquichloride and ethylaluminum sesquibromide; partially halogenated alkylaluminums such as alkylaluminum dihalides such as ethylaluminum dichloride, propylaluminum dichloride and butylaluminum dibromide Dialkylaluminum hydrides such as diethylaluminum hydride and dibutylaluminum hydride; other partially hydrogenated alkylaluminums such as alkylaluminum dihydrides such as ethylaluminum dihydride and propylaluminum dihydride; ethylaluminum ethoxycyclolide and butylaluminum butoxy Chloride, ethylaluminum ethoxybro Mention may be made of partially alkoxylated and halogenated alkylaluminums such as mido.

Examples of the compound similar to (i) include an organic aluminum compound in which two or more aluminum atoms are bonded via an oxygen atom or a nitrogen atom. Such compounds include, for example, Methyl aluminoxane and the like can be mentioned.

Examples of the compound belonging to (ii) include LiAl (C ₂ H ₅ ) ₄ and LiAl (C ₇ H ₁₅ ) ₄ .

Among these, it is particularly preferable to use trialkylaluminum or alkylaluminum to which two or more aluminum compounds described above are bonded.

In the present invention, an electron donor [C] can be used as necessary when producing the catalyst component for olefin polymerization. Examples of such an electron donor [C] include alcohols, phenols, and ketones. Aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, acid amides, acid anhydrides, oxygen-containing electron donors such as alkoxysilanes, ammonia, amines, nitriles, nitrogen-containing electron donors such as isocyanates, or the above And the like. More specifically, methanol, ethanol, propanol, pentanol, hexanol, octanol, dodecanol, octadecyl alcohol, oleyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol, isopropyl alcohol, cumyl alcohol, isopropylbenzyl alcohol, etc. Alcohols having 1 to 18 carbon atoms; phenols having 6 to 20 carbon atoms which may have a lower alkyl group such as phenol, cresol, xylenol, ethylphenol, propylphenol, nonylphenol, cumylphenol, and naphthol; C3-C15 ketones such as methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, zenzoquinone; acetaldehyde, propiona Aldehydes having 2 to 15 carbon atoms such as aldehyde, octylaldehyde, benzaldehyde, tolualdehyde and naphthaldehyde; methyl formate, methyl acetate, ethyl acetate, vinyl acetate,
Propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, ethyl crotonate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, benzoate Propyl acrylate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate, ethyl benzoate, methyl anisate, n-butyl maleate, Diisobutyl methylmalonate, di-n-hexyl cyclohexenecarboxylate, diethyl nadicate, diisopropyl tetrahydrophthalate, diethyl phthalate, diisobutyl phthalate, di-n-butyl phthalate, di-2-ethyl phthalate Organic acid esters having 2 to 30 carbon atoms such as xyl, γ-butyrolactone, δ-valerolactone, coumarin, phthalide, and ethylene carbonate; 2 to 15 carbon atoms such as acetyl chloride, enzayl chloride, toluic acid chloride, and anisic acid chloride Acid halides; methyl ether, ethyl ether, isopropyl ether, butyl ether, amyl ether, tetrahydrofuran, anisole, diphenyl ether epoxy-p
Ethers and diethers having 2 to 20 carbon atoms such as menthane; acid amides such as acetic acid amide, benzoic acid amide, toluic acid amide; methylamine, ethylamine, diethylamine, tributylamine, piperidine, tribenzylamine, aniline, Amines such as pyridine, picoline and tetramethylenediamine; nitriles such as acetonitrile, benzonitrile and tolunitrile; acid anhydrides such as acetic anhydride, phthalic anhydride and benzoic anhydride are used.

Further, as the electron donor [C], an organosilicon compound represented by the following general formula [Ia] can also be used.

_{R n Si (OR ') 4} -n ... [I a] [ wherein, R and R' is a hydrocarbon group, 0 <n <4
Specific examples of the organosilicon compound represented by the above general formula [Ia] include trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, and t- Butylmethyldimethoxysilane, t
-Butylmethyldiethoxysilane, t-amylmethyldiethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, bis-o-tolyldimethoxysilane, bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxysilane,
Bis-p-tolyldiethoxysilane, bisethylphenyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n -Propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, γ-
Chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane, n-butyltriethoxysilane, iso-butyltriethoxysilane, phenyltriethoxysilane, γ-amino Propyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, 2-norbornanetrimethoxysilane, 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxy Silane, ethyl silicate, butyl silicate, trimethylphenoxy silane, methyl triaryloxy (allyloxy) silane, vinyl tris (β-methoxyethoxy silane), Sulfonyl triacetoxy silane,
Dimethyltetraethoxydisiloxane or the like is used.

Among them, ethyltriethoxysilane, n-propyltriethoxysilane, t-butyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, vinyltributoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, bis-p-tolyldimethoxysilane Preferred are silane, p-tolylmethyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, and diphenyldiethoxysilane.

Further, as the electron donor [C], an organosilicon compound represented by the following general formula [IIa] can be used.

SiR ¹ R ² _m (OR ³ ) _3-m ... [IIa] wherein R ¹ is a cyclopentyl group or a cyclopentyl group having an alkyl group, and R ² is an alkyl group, a cyclopentyl group and cyclopentyl having an alkyl group A group selected from the group consisting of groups, R ³ is a hydrocarbon group, and m is 0 ≦ m ≦ 2. In the above formula [IIa], R ¹ is a cyclopentyl group or a cyclopentyl group having an alkyl group, and as R ¹ , other than a cyclopentyl group, a 2-methylcyclopentyl group, a 3-methylcyclopentyl group, a 2-ethylcyclopentyl And a cyclopentyl group having an alkyl group such as a 2,3-dimethylcyclopentyl group.

In the formula [IIa], R ² is any one of an alkyl group, a cyclopentyl group and a cyclopentyl group having an alkyl group, and R ² is, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, butyl group, an alkyl group such as hexyl, or cyclopentyl group having an exemplified cyclopentyl group and an alkyl group as R ¹ can be exemplified similarly.

Further, in the formula [IIa], R ³ is a hydrocarbon group,
As R ³ , for example, an alkyl group, a cycloalkyl group,
And hydrocarbon groups such as aryl groups and aralkyl groups.

Among these, it is preferable to use an organosilicon compound in which R ¹ is a cyclopentyl group, R ² is an alkyl group or a cyclopentyl group, and R ³ is an alkyl group, particularly a methyl group or an ethyl group.

Specific examples of such organosilicon compounds include trialkoxysilanes such as cyclopentyltrimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethylcyclopentyltrimethoxysilane, and cyclopentyltriethoxysilane; dicyclopentyldimethoxy Dialkoxysilanes such as silane, bis (2-methylcyclopentyl) dimethoxysilane, bis (2,3-dimethylcyclopentyl) dimethoxysilane and dicyclopentyldiethoxysilane; tricyclopentylmethoxysilane, tricyclopentylethoxysilane, dicyclopentylmethylmethoxy Silane, dicyclopentylethylmethoxysilane, dicyclopentylmethylethoxysilane, cyclopentyldimethylmethoxysilane, cyclopentyldi Chill silane, mono-alkoxysilanes such as cyclopentyl dimethylethoxysilane, and the like.
Among these electron donors, organic carboxylic acid esters or organic silicon compounds are preferable, and organic silicon compounds are particularly preferable.

In the present invention, the olefin polymerization comprising the solid catalyst component [A] as described above, the organometallic compound catalyst component [B] of the Group I to Group III metal of the periodic table, and, if necessary, the electron donor [C]. The olefin is polymerized using a catalyst for olefin polymerization. In this case, it is preferable that the olefin polymerization catalyst is preliminarily polymerized with an α-olefin. This prepolymerization is
0.1 to 500 g per gram of olefin polymerization catalyst, preferably 0.3 to 500 g
It is carried out by prepolymerizing the α-olefin in an amount of 300 g, particularly preferably 1 to 100 g.

In the prepolymerization, a catalyst having a considerably higher concentration than the catalyst concentration in the system in the main polymerization can be used.

The concentration of the solid catalyst component [A] in the prepolymerization is calculated as titanium atom conversion per inert hydrocarbon medium 1 described below.
Usually, it is desired to be in the range of about 0.01 to 200 mmol, preferably about 0.1 to 100 mmol, particularly preferably 1 to 50 mmol.

The amount of the organometallic compound catalyst component [B] may be an amount that produces 0.1 to 500 g, preferably 0.3 to 300 g of polymer per 1 g of the solid catalyst component [A]. The amount is usually about 0.1 to 100 mol, preferably about 0.5 to 50 mol, particularly preferably 1 to 20 mol, per mol of titanium atom.

The electron donor [C] is used as needed, and is used in an amount of 0.1 to 50 mol, preferably 0.5 to 30 mol, particularly preferably 1 to 10 mol, per 1 mol of titanium atom in the solid catalyst component [A]. It is preferable to use them.

The prepolymerization is preferably carried out under mild conditions by adding an olefin and the above-mentioned catalyst component to an inert hydrocarbon medium.

As the inert hydrocarbon medium used at this time, specifically, aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane and kerosene; cyclopentane, cyclohexane, methylcyclopentane, etc. Alicyclic hydrocarbons; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethylene chloride and chlorobenzene, and mixtures thereof. Among these inert hydrocarbon media, it is particularly preferable to use aliphatic hydrocarbons. In addition, it is also possible to perform prepolymerization using the olefin itself as a solvent,
Prepolymerization can be carried out in a substantially solvent-free state.

The olefin used in the prepolymerization may be the same as or different from the olefin used in the main polymerization described below, and specifically, propylene is preferred.

The reaction temperature during the prepolymerization is usually about -20 to + 100 ° C,
Preferably, about -20 to + 80 ° C, more preferably 0 to +
It is desirable to be in the range of 40 ° C.

In the prepolymerization, a molecular weight regulator such as hydrogen can be used. Such molecular weight regulators are
It is desirable to use the polymer in an amount such that the intrinsic viscosity [η] of the polymer obtained by prepolymerization measured in decalin at 135 ° C. is about 0.2 dl / g or more, preferably about 0.5 to 20 dl / g.

As described above, the prepolymerization is desirably carried out so as to produce about 0.1 to 500 g, preferably about 0.3 to 300 g, particularly preferably 1 to 100 g of polymer per 1 g of the solid catalyst component [A]. If the prepolymerization amount is too large, the production efficiency of the olefin polymer may decrease.

The prepolymerization can be performed in a batch system or a continuous system.

Examples of the olefin that can be used in the main polymerization include olefins having 2 to 20 carbon atoms such as ethylene, propylene, 1-butene, 4-methyl-1-pentene, and 1-octene. In the polymerization method of the present invention,
These olefins can be used alone or in combination. Of these olefins,
The copolymerization is preferably performed using a mixed olefin containing ethylene as a main component. In the present invention, it is particularly preferable to copolymerize ethylene with 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene. When such copolymerization is carried out, the constituent units derived from ethylene are preferably present in the obtained copolymer in an amount of usually at least 50 mol%, preferably at least 70 mol%.

When performing homopolymerization or copolymerization of these olefins, a compound having a polyunsaturated bond such as a conjugated diene or a non-conjugated diene can be used as a polymerization raw material.

In the polymerization method of the present invention, the main polymerization of the olefin,
Usually, the reaction is performed in a gas phase or a liquid phase.

When the main polymerization takes a reaction mode of slurry polymerization, the above-mentioned inert hydrocarbon or a liquid olefin at the reaction temperature can be used as the reaction solution.

In the polymerization method of the present invention, [A] is an organometallic compound catalyst component [B], and a metal atom is usually about 1 to 20 per mole of titanium atom in a prepolymerization catalyst component in a polymerization system.
It is used in an amount such that it amounts to 00 mol, preferably about 5 to 500 mol. Further, if necessary, the electron donor [C]
The amount is usually about 0.001 to 10 mol, preferably about 0.01 to 2 mol, particularly preferably about 0.05 to 1 mol, per 1 mol of metal atom in the organometallic compound catalyst component [C].

If hydrogen is used during the main polymerization, the molecular weight of the obtained polymer can be adjusted, and a polymer having a high melt flow rate can be obtained.

In the present invention, the polymerization temperature of the olefin is usually about
At 20-200 ° C, preferably about 50-100 ° C, the pressure is usually
The pressure is set at normal pressure to 100 kg / cm ² , preferably about ² to 50 kg / cm ² . In the polymerization method of the present invention, the polymerization is a batch type,
It can be carried out by any of a semi-continuous method and a continuous method. Further, the polymerization can be carried out in two or more stages by changing the reaction conditions.

The olefin polymer thus obtained may be any of a homopolymer, a random copolymer and a block copolymer.

When the olefin is (co) polymerized using the olefin polymerization catalyst as described above, a granular or spherical olefin polymer, particularly an ethylene polymer, having a good particle size distribution and an excellent bulk specific gravity can be obtained.

Further, in the present invention, since the yield of the polymer per olefin polymerization catalyst is high, the catalyst residue, particularly the halogen content, in the polymer can be relatively reduced. Therefore,
The operation of removing the catalyst in the polymer can be omitted,
When molding a molded body using the generated olefin polymer,
Rust of the mold can be effectively prevented.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Example 1 [Preparation of solid titanium catalyst component [A-1]] 19.0 g of anhydrous magnesium chloride, 88.4 ml of decane and 2
78.1 g of ethylhexyl alcohol was heated at 140 to 150 ° C. for 2 hours to give a homogeneous solution. Thereafter, the mixture was cooled to room temperature, and 4.43 g of phthalic anhydride was added to this solution and added at 130 ° C.
For 1 hour to obtain a homogeneous solution. After cooling 75 ml of the thus obtained homogeneous solution to room temperature, it was dropped into 200 ml of titanium tetrachloride kept at -20 ° C over 45 minutes. After completion of the charging, the temperature of the mixture was raised to 110 over 4 hours.
The temperature was raised to 110 ° C, and when the temperature reached 110 ° C, 5.03 ml of diisobutyl phthalate was added, followed by stirring at 110 ° C for 2 hours. Thereafter, a solid portion was collected by hot filtration, and the solid portion was resuspended in 275 ml of titanium tetrachloride. The thermal reaction was performed again at 110 ° C. for 2 hours. After the completion of the reaction, the solid portion was collected again by hot filtration, and sufficiently washed with decane and hexane at 110 ° C. until no free titanium compound was detected in the washing solution. The composition of the solid titanium catalyst component [A-1] thus obtained was 2.4% by weight of titanium, 19% by weight of magnesium and 12.4% by weight of diisobutyl phthalate.

[Preparation of solid catalyst component [A]] The above solid titanium catalyst component [A-1] of 2 mg atom in terms of titanium atom was suspended in 200 ml of hexane, and
Cooled to ° C. At that temperature, 15.4 ml of a hexane solution of diethyl aluminum ethoxide (Al = 1.0 mol /) was added. Thereafter, the temperature was raised to 50 ° C., and the reaction was carried out at 50 ° C. for 2 hours.
After the completion of the reaction, a solid portion was recovered by filtration and washed sufficiently with hexane. The solid catalyst component [A] thus obtained has a composition of 2.3% by weight of titanium, 19% by weight of magnesium, 2.8% by weight of ethoxy group, 12.2% by weight of diisobutyl phthalate.
1% by weight.

[Preliminary polymerization] 200 m of hexane was placed in a 400 ml flask which was sufficiently purged with nitrogen.
l, 3 mmol of triethylaluminum and 1 mg of the above-mentioned solid catalyst component [A] are charged in an amount of 1 mg in terms of titanium atom, and then continuously supplied with propylene gas at 20 ° C.
, About 6 g of propylene was prepolymerized for 1 hour.
The prepolymerized solid component thus obtained was recovered by filtration, washed with hexane for filling, and used for the main polymerization.

[Main polymerization] 150 g of sodium chloride (special grade of Wako Pure Chemical Industries, Ltd.) is charged into a stainless steel autoclave of 2 which is sufficiently purged with nitrogen, and 90
It dried under reduced pressure at 1 degreeC for 1 hour. Thereafter, the inside of the system was returned to room temperature and normal pressure, and the atmosphere was further changed to an ethylene atmosphere. Then, 0.75 mmol of triethyl aluminum and 8.5 ml of 1-hexene were added. Thereafter, the temperature was raised to 50 ° C., 1.8 kg / cm ^{2 of} hydrogen gas was introduced, and at around 70 ° C., the prepolymerized solid component obtained above (0.01 mg atom in terms of titanium atom) was injected with ethylene to initiate polymerization. did. Ethylene and 1-hexene 34
While continuously supplying ml, ethylene and 1-hexene were copolymerized at a total pressure of 8 kg / cm ² -G80 ° C. for 1 hour.

After completion of the polymerization, sodium chloride was removed by washing with water and the polymer was washed with methanol, followed by drying overnight at 80 ° C. under reduced pressure. As a result, the MFR measured at 190 ° C under a load of 2.16 kg was 1.84.
g / 10 min, density 0.918 g / cm ³ , bulk specific gravity 0.42 g / cm ³ , 23 ° C
As a result, 119 g of an ethylene-1-hexene copolymer having a decane-soluble component amount of 14.4% by weight, a melting point measured by DSC of 125.2 ° C., and an average polymer particle size of 390 μm were obtained.

Comparative Example 1 In Example 1, the solid titanium catalyst component [A-1] was not treated with diethyl aluminum ethoxide,
-The procedure was as in Example 1, except that 30 ml of hexene were initially supplied continuously at 7.5 ml. As a result, MFR is 1.40g
/ 10 min, density of 0.919 g / cm ^3, bulk density 0.31 g / cm ^3, decane-soluble component quantity polymer 93g was obtained a 16.6% by weight.

Example 2 [Preparation of solid catalyst component [A]] The same procedures as in Example 1 were carried out except that the amount of the hexane solution of diethylaluminum ethoxy used was changed to 24 ml. Thus, a solid catalyst component [A] having a weight percentage of 3.2% by weight of ethoxy groups and 11.9% by weight of diisobutyl phthalate was obtained.

[Polymerization] When prepolymerization and main polymerization were carried out in the same manner as in Example 1, the MFR was 1.27 g / 10 min, the density was 0.921 g / cm ³ , and the bulk specific gravity was
0.43 g / cm ³ , the amount of decane-soluble components at 23 ° C. is 12.6% by weight,
138 g of an ethylene-1-hexene copolymer having a melting point of 125.2 ° C. and an average polymer particle size of 390 μm were obtained.

Example 3 [Preparation of solid catalyst component [A]] Example 1 was the same as Example 1 except that the amount of the hexane solution of diethylaluminum ethoxide was changed to 6 ml.
As a result, a solid catalyst component [A] containing 2.3% by weight of titanium, 19% by weight of magnesium, 2.7% by weight of an ethoxy group, and 12.9% by weight of diisobutyl phthalate was obtained.

[Polymerization] When prepolymerization and main polymerization were carried out in the same manner as in Example 1, the MFR was 2.46 g / 10 min, the density was 0.922 g / cm ³ , and the bulk specific gravity was
0.42 g / cm ³ , the content of decane-soluble components at 23 ° C. is 14.1% by weight,
158 g of an ethylene-1-hexene copolymer having a melting point of 125.7 ° C. and an average polymer particle size of 380 μm were obtained.

Example 4 [Preparation of solid catalyst component [A]] The procedure of Example 1 was repeated, except that 15.4 mmol of diethylaluminum 2-ethylhexoxide was used instead of diethylaluminum ethoxide. 2.2% by weight, 18% by weight of magnesium,
As a result, a solid catalyst component [A] having 1.1% by weight of 2-ethylhexoxy group was obtained.

[Polymerization] When prepolymerization and main polymerization were performed in the same manner as in Example 1, the MFR was 1.46 g / 10 min, the density was 0.922 g / cm ³ , and the bulk specific gravity was 0.4.
126 g of an ethylene-1-hexene copolymer having a decane-soluble component amount of 32.9 g / cm ³ and 12.9% by weight at 23 ° C. was obtained.

Example 5 In the polymerization of Example 2, 1-hexene was replaced by 1-hexene.
Penten was used as a comonomer (7.5 ml added initially,
The polymerization was carried out in the same manner as in Example 2 except that 30 ml was continuously fed over 1 hour. The MFR was 1.18 g / 10
Ethylene having a density of 0.920 g / cm ³ , a bulk density of 0.45 g / cm ³ , an amount of decane-soluble components at 23 ° C. of 12.5% by weight, a melting point of 123.9 ° C., and an average polymer particle size of 370 μm. 126 g of a pentene copolymer was obtained.

Example 6 Instead of 1-hexene in the polymerization of Example 2, 1-
Polymerization was carried out in the same manner as in Example 2 except that pentene was used as a comonomer (initial 6 ml was added, and then 24 ml was continuously supplied over 1 hour). The MFR was 1.58 g / 10
Min, density of 0.924 g / cm ^3, bulk density 0.46 g / cm ^3, 23-decane-soluble component is 9.7 wt% at ° C., a melting point of 124.6 ° C., an average polymer particle size of 360μm ethylene-1 116 g of a pentene copolymer was obtained.

[Brief description of the drawings]

FIG. 1 is an illustration of an olefin polymerization catalyst according to the present invention.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-297304 (JP, A) JP-A-1-292010 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 4/60-4/658 C08F 10/00-10/14 C08F 110/00-110/14 C08F 210/00-210/18

Claims (3)

(57) [Claims] 1. [A] A solid titanium catalyst component [A] containing magnesium, titanium and halogen as essential components.
-1] and Al represented by the following general formula [I] or [II]
An organoaluminum compound having a -O bond solid catalyst component obtained by contacting the [A-2] _{^{and, R 10 n Al (OR 11}} ) m X 3-nm ... [I] R 10 n Al (OCOR 11) _m X _3-nm ... [II] [wherein, R ¹⁰ is a hydrocarbon group having 1 to ¹⁰ carbon atoms, and R ¹¹ is a hydrocarbon group having 1 to 20 carbon atoms or SiR ₃ ¹² (wherein
R ¹² is a hydrocarbon group having 1 to 10 carbon atoms), X is halogen or hydrogen, m ≧ 1, and n is 1 or 2. ] And [B] an olefin polymerization catalyst formed from the organoaluminum compound catalyst component. 2. A solid titanium catalyst component [A] containing magnesium, titanium and halogen as essential components.
-1] and Al represented by the following general formula [I] or [II]
An organoaluminum compound having a -O bond solid catalyst component obtained by contacting the [A-2] _{^{and, R 10 n Al (OR 11}} ) m X 3-nm ... [I] R 10 n Al (OCOR 11) _m X _3-nm ... [II] [wherein, R ¹⁰ is a hydrocarbon group having 1 to ¹⁰ carbon atoms, and R ¹¹ is a hydrocarbon group having 1 to 20 carbon atoms or SiR ₃ ¹² (wherein
R ¹² is a hydrocarbon group having 1 to 10 carbon atoms), X is halogen or hydrogen, m ≧ 1, and n is 1 or 2. ] And [B] an olefin polymerization catalyst formed from the organoaluminum compound catalyst component, and an α-olefin prepolymerized. 3. A method for polymerizing olefins, comprising polymerizing or copolymerizing olefins in the presence of the catalyst for olefin polymerization according to claim 1 or 2.