JPH09104714A - Method for polymerizing alpha-olefin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a highly stereoregular poly-α-olefin by using a catalyst comprising a highly active Ti catalyst component comprising Mg, Ti, a halogen and a polycarboxylid acid ester, an organometallic compound, a specified Ti compound and a specified Si compound. SOLUTION: MgCl2 is dissolved under heating in 2-ethylhexanol, TiCl4 is added dropwise to the solution, and the mixture is heated and then reacted with an electron donor such as diisobutyl phthalate to prepare a highly active Ti solid catalyst. An α-olefin such as propylene is prepolymerized in the presence of a catalyst comprising the Ti solid catalyst, an organometallic compound such as triethylaluminum, a Ti compound (e.g. TiCl4 ) represented by the formula: Ti(OR)g X4-g (wherein X is a halogen; and 0<=g<=4) and an Si compound (e.g. diphenyldimethoxysilane) represented by the formula: Rn Si(OR<1> )4-n (wherein 0<=n<=3; and R and R<1> are each an alkyl or the like). An autoclave is charged with the prepolymerization catalyst and filled with H2 . An α-olefin is fed into the autoclave and polymerized at about 50-180 deg.C under a pressure of about 2-50kg/cm<2> to obtain a poly-α-olefin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for polymerizing α-olefin, and more particularly to a method capable of producing poly α-olefin having excellent stereoregularity with high catalytic activity. More specifically, in a method of polymerizing α-olefin by using a highly active α-olefin prepolymerization catalyst having excellent stereoregularity, higher activation can be achieved without lowering the stereoregularity. Regarding the method.

[0002]

2. Description of the Related Art A method for producing crystalline polyolefin by polymerizing .alpha.-olefin such as propylene or 1-butene in the presence of a stereoregular catalyst has been proposed and known in many prior arts. Among these polymerization methods, from (a) a highly active titanium solid catalyst component containing magnesium, titanium, halogen and an electron donor as essential components, (b) an organometallic compound catalyst component and (C) an electron donor catalyst component, Many prior art methods have also been proposed in which a highly stereoregular polymer can be obtained with high catalytic activity by polymerizing α-olefin in the presence of a catalyst to be formed. It has been adopted on an industrial scale as an excellent polymerization method that does not require the removal of catalyst and amorphous polymer from the coalescence. However, there is a great demand in the art for streamlining technology, and a highly activated polymerization technology is required.

On the other hand, the present applicant has already filed Japanese Patent Publication No. 57-31.
Japanese Patent No. 726 discloses a titanium catalyst component obtained by treating a magnesium-halogen compound / titanium-halogen compound complex with an organic acid ester and a titanium compound, and an organometallic compound of a metal of Groups 1 to 3 of the periodic table. A method of polymerizing .alpha.-olefin in the presence of a titanium compound and a metal of Group 1 to Group 3 of the periodic table in the presence of a magnesium halogen compound / titanium halogen compound complex is disclosed in Japanese Patent Publication No. 56-45403. A method for polymerizing olefin in the presence of a catalyst comprising a solid catalyst component (A) obtained by reacting an organometallic compound of (1) and an organometallic compound component (B) of a metal of Group 1 to 3 of the periodic table is proposed. ing. However, all of these methods have low polymerization activity and stereoregularity, and there is a demand for a polymerization method having more excellent performance.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have found that α-
Recognizing that the technology in the field of olefin polymerization is in the above situation, conventionally proposed (a) magnesium,
Polymerization of α-olefin in the presence of a catalyst formed from a highly active titanium solid catalyst component containing titanium, halogen and an electron donor as essential components, (b) an organometallic compound catalyst component and (c) an electron donor catalyst component. In the method of making
As a result of diligent studies on a method capable of achieving high activation of the catalyst without deteriorating the stereoregularity, at least a high-activity titanium solid catalyst component (A), an organometallic compound catalyst component (B) and a transition metal compound By polymerizing α-olefin in the presence of an α-olefin prepolymerization catalyst obtained by prepolymerizing α-olefin in the presence of a catalyst formed from catalyst component (C) The inventors have reached the present invention by finding out what is achieved.

[0005]

According to the present invention, at least (A) a highly active solid titanium catalyst component containing magnesium, titanium and halogen as essential components, and (B) a group 1 to group 1 of the periodic table. The α-olefin is prepolymerized in the presence of a catalyst formed from a Group 3 metal organometallic compound catalyst component and (C) a transition metal compound catalytic component soluble in an inert organic medium, resulting in α-olefin. Provided is a method for polymerizing α-olefin, which comprises polymerizing α-olefin in the presence of an olefin prepolymerization catalyst.

Hereinafter, the present invention will be described in detail.

In the present invention, the term "polymerization" may be used to include not only homopolymerization but also copolymerization, and the term "polymer" may be used to include not only homopolymer but also copolymer. Sometimes.

The titanium catalyst component (A) used in the present invention comprises:
With magnesium, titanium and halogen as essential components,
It is a highly active catalyst component containing a specific electron donor described later as an optional component. The titanium catalyst component (A) is compared to a commercially available magnesium halide, containing a small magnesium halide microcrystals, typically, a specific surface area of from about 3m ² / g or more, preferably about 40 to about 1000 m ² / g, more preferably about 80 to about 800 m ² / g, and hexane washing at room temperature does not substantially change the composition. In the titanium catalyst component (A), the halogen / titanium (atomic ratio) is about 5 to about 200, especially about 5
To about 100, electron donor / titanium (molar ratio) of about 0.1 to about 10, especially about 0.2 to about 6, magnesium / titanium (atomic ratio) of about 2 to about 100, especially about 4 It is preferably about 50 to about 50. The component (A) may also contain other electron donors, metals, elements, functional groups and the like. It may also contain organic or inorganic diluents such as silicon compounds, aluminum and polyolefin.

Such titanium catalyst component (A) can be obtained, for example, by mutual contact of a magnesium compound (or magnesium metal), optionally an electron donor and a titanium compound, or optionally other reactions. Reagents such as compounds of silicon, phosphorus, aluminum and the like can be used.

Examples of the method for producing the titanium catalyst component (A) include, for example, JP-A Nos. 50-108385, 50-126590, 51-20297 and 51-20.
-28189, 51-64586, 51-92
No. 885, No. 51-136625, No. 51-8748
No. 9, No. 52-100576, No. 52-147688
No. 52-104593, No. 53-2580, No. 53-40093, No. 53-43094, No. 55-.
No. 135102, No. 56-135103, No. 56-8
No. 11, 56-11908, 56-18606
No. 58-83006, No. 58-138705,
58-138706, 58-138707, 58-138708, 58-138709, 5
8-138710, 58-138715, 60
No. 23404, No. 61-21109, No. 61-37
No. 802, No. 61-37803, No. 55-15271
It can be produced according to the method disclosed in each publication such as No. 0. Some examples of the method for producing the titanium catalyst component (A) will be briefly described below.

(1) An electron donor and / or a magnesium compound or a complex compound of a magnesium compound and an electron donor is crushed or not crushed in the presence or absence of an electron donor, a grinding aid, or the like. It is pretreated with a reaction aid such as an organoaluminum compound or a halogen-containing silicon compound, or is reacted with a titanium compound that forms a liquid phase under the reaction conditions with the solid obtained without pretreatment.

(2) A liquid titanium compound having no reducing ability is reacted with a liquid titanium compound in the presence or absence of an electron donor to precipitate a solid titanium complex. (3) The titanium compound is reacted with the product obtained in (2).

(4) An electron donor and a titanium compound are reacted with those obtained in (1) and (2).

(5) A magnesium compound or a complex compound of a magnesium compound and an electron donor is ground in the presence or absence of an electron donor, a grinding aid, etc., and in the presence of a titanium compound to obtain an electron donor and an electron donor. / Or pretreatment with a reaction aid such as an organoaluminum compound or a halogen containing silicon compound, or the solid obtained without pretreatment is treated with halogen or a halogen compound or an aromatic hydrocarbon.

(6) The compounds obtained in the above (1) to (4) are treated with halogen or a halogen compound or an aromatic hydrocarbon.

Among these preparation methods, it is preferable to use liquid titanium halide in the catalyst preparation, or to use halogenated hydrocarbon after or after using the titanium compound.

The electron donors that can be the constituents of the highly active titanium catalyst component (A) of the present invention include alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, Examples thereof include oxygen-containing electron donors such as acid amides and acid anhydrides, nitrogen-containing electron donors such as ammonia, amines, nitriles and isocyanates.

More specifically, carbon such as methanol, ethanol, propanol, pentanol, hexanol, octanol, 2-ethylhexanol, dodecanol, octadecyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol and isopropylbenzyl alcohol. Alcohols of the numbers 1 to 18; phenol, cresol, xylenol, ethylphenol, propylphenol, cumylphenol,
C6 to C25 phenols which may have an alkyl group such as nonylphenol and naphthol; acetone,
C3 to C15 ketones such as methyl ethyl ketone, methyl isobutyl ketone, acetophenone and benzophenone; acetaldehyde, propionaldehyde,
C2-C15 aldehydes such as octyl aldehyde, benzaldehyde, tolualdehyde, naphthaldehyde; methyl formate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, Ethyl stearate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, ethyl crotonic acid, dibutyl maleate, diethyl butylmalonate, diethyl dibutylmalonate, ethyl cyclohexanecarboxylate, diethyl 1,2-cyclohexanedicarboxylate, 1, 2-Cyclohexanedicarboxylate di2-ethylhexyl, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzoate Benzyl, methyl toluate,
Ethyl toluate, amyl toluate, ethyl benzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, dimethyl phthalate, diethyl phthalate,
Organic acid esters having 2 to 30 carbon atoms, including the following esters, which are preferably contained in titanium catalyst components such as dibutyl phthalate, dioctyl phthalate, γ-butyrolactone, δ-valerolactone, coumarin, phthalide, and ethylene carbonate; Inorganic acid esters such as ethyl silicate, butyl silicate, vinyltriethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane; acetyl chloride, benzoyl chloride, toluic acid chloride, anisic acid chloride, phthalic acid dichloride, etc. Acid halides having 2 to 15 carbon atoms; methyl ether, ethyl ether, isopropyl ether, butyl ether,
C2-C20 ethers such as amyl ether, tetrahydrofuran, anisole and diphenyl ether; acid amides such as acetic acid amide, benzoic acid amide and toluic acid amide; acid anhydrides such as benzoic anhydride and phthalic anhydride; Examples thereof include amines such as methylamine, ethylamine, diethylamine, tributylamine, piperidine, tribenzylamine, aniline, pyridine, picoline and tetramethylethylenediamine; nitriles such as acetonitrile, benzonitrile and tolunitrile; and the like. Two or more of these electron donors can be used.

The electron donor that is preferably contained in the titanium catalyst component is an ester, and more preferable one is the general formula

[0020]

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(Wherein R ¹ is a substituted or unsubstituted hydrocarbon group, R ² , R ⁵ and R ⁶ are hydrogen or a substituted or unsubstituted hydrocarbon group, and R ³ and R ⁴ are hydrogen or a substituted or unsubstituted hydrocarbon group. a substituted hydrocarbon group, preferably at least one substituted or unsubstituted hydrocarbon group. the R ³ and R ⁴ may be linked to each other. carbonization of substitution of the R ¹ to R ⁶ The hydrogen group includes heteroatoms such as N, O and S, and is, for example, C—O—C, COOR, COOH, OH, SO ₃ H, —
It has a group such as C—N—C— and NH ₂ . An example is one having a skeleton represented by).

Particularly preferred among these are diesters of dicarboxylic acids in which at least one of R ¹ and R ² is an alkyl group having 2 or more carbon atoms.

Specific examples of preferred polycarboxylic acid esters include diethyl succinate, dibutyl succinate, diethyl methyl succinate, diisobutyl α-methyl glutarate, dibutyl methyl malonate, diethyl malonate, diethyl ethyl malonate, isopropyl. Diethyl malonate, diethyl butyl malonate, diethyl phenylmalonate, diethyl diethylmalonate, diethyl allyl malonate, diethyl diisobutylmalonate, diethyl dinormal butylmalonate, dimethyl maleate, monooctyl maleate, dioctyl maleate, dibutyl maleate. , Butyl dimaleate, diethyl butyl maleate, diisopropyl β-methyl glutarate, diallyl ethyl succinate, di-2-ethylhexyl fumarate, diethyl itaconate Cyl, dibutyl itaconate, dioctyl citracone, dimethyl citraconate, etc. Aliphatic polycarboxylic acid esters such as diethyl 1,2-cyclohexanecarboxylate, diisobutyl 1,2-cyclohexanecarboxylate, diethyl tetrahydrophthalate, diethyl nadicuate Alicyclic polycarboxylic acid ester, monoethyl phthalate, dimethyl phthalate, methyl ethyl phthalate, monoisobutyl phthalate, mononormal butyl phthalate, diethyl phthalate, ethyl isobutyl phthalate, ethyl normal butyl phthalate, phthalic acid Di n-propyl, diisopropyl phthalate, di n-butyl phthalate, diisobutyl phthalate, di n-heptyl phthalate,
Di-2-ethylhexyl phthalate, di-n-octyl phthalate, dineopentyl phthalate, didecyl phthalate, benzylbutyl phthalate, diphenyl phthalate, diethyl naphthalene dicarboxylate, dibutyl naphthalene dicarboxylate, triethyl trimellitate, dibutyl trimellitate, etc. The heterocyclic polycarboxylic acid ester such as 3,4-furandicarboxylic acid and the like.

Specific examples of preferable polyhydric hydroxy compound esters include 1,2-diacetoxybenzene, 1-methyl-2,3-diacetoxybenzene, 2,3-diacetoxynaphthalene and ethylene glycol dipivalate. , Butanediol pivalate and the like.

Examples of the hydroxy-substituted carboxylic acid ester include benzoylethyl salicylate, acetylisobutyl salicylate, acetylmethyl salicylate and the like.

Other examples of the polycarboxylic acid ester which can be supported in the titanium catalyst component include diethyl adipate, diisobutyl adipate, diisopropyl sebacate, di-n-butyl sebacate and di-n-sebacate.
Examples thereof include long-chain dicarboxylic acid esters such as octyl and di-2-ethylhexyl sebacate.

Among these polyfunctional esters, those having a skeleton of the above-mentioned general formula are preferable, and more preferable are phthalic acid, maleic acid, substituted malonic acid and the like and an alcohol having 2 or more carbon atoms. Esters, particularly preferably diesters of phthalic acid and alcohols having 2 or more carbon atoms.

Another electron donor component which can be supported on the titanium catalyst component is RCOOR '(R and R'are hydrocarbyl groups which may have a substituent, at least one of which is a branched chain ( It is a monocarboxylic acid ester represented by (including alicyclic) or a ring-containing chain group). For example, as R and / or R ′,

[0029]

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It may be a group such as If either R or R'is a group as described above, the other may be the above group, or another group such as a linear or cyclic group.

Specifically, dimethylacetic acid, trimethylacetic acid, α-methylbutyric acid, β-methylbutyric acid, methacrylic acid,
Various monoesters such as benzoyl acetic acid, isopropanol, isobutyl alcohol, tert-butyl alcohol,
Various monocarboxylic acid esters of alcohols such as can be exemplified.

Carbonates can also be selected as electron donors. Specifically, diethyl carbonate, ethylene carbonate, diisopropyl carbonate, phenylethyl carbonate, diphenyl carbonate, etc. can be illustrated.

In carrying these electron donors,
It is not necessary to use these as starting materials,
Compounds that can be converted into these during the preparation of the titanium catalyst component may be used and converted into these compounds at the stage of the preparation.

Other electron donors may coexist in the titanium catalyst component, but if they coexist in too large an amount, it will have an adverse effect and should be limited to a small amount.

In the present invention, the magnesium compound used for preparing the solid titanium catalyst component (A) is a magnesium compound with or without reducing ability. As an example of the former, a magnesium compound having a magnesium-carbon bond or a magnesium-hydrogen bond, for example, dimethyl magnesium, diethyl magnesium, dipropyl magnesium, dibutyl magnesium, diamyl magnesium,
Examples thereof include dihexyl magnesium, didecyl magnesium, ethyl magnesium chloride, propyl magnesium chloride, butyl magnesium chloride, hexyl magnesium chloride, amyl magnesium chloride, butyl ethoxy magnesium, ethyl butyl magnesium and butyl magnesium hydride. These magnesium compounds can be used in the form of a complex compound with, for example, organoaluminum, and can be in a liquid state or a solid state. On the other hand, examples of magnesium compounds having no reducing ability include magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide, and magnesium fluoride; magnesium methoxy chloride, magnesium ethoxy chloride, magnesium isopropoxy chloride, magnesium butoxy chloride, octoxy. Alkoxy magnesium halides such as magnesium chloride; Allyloxy magnesium halides such as phenoxy magnesium chloride, methyl phenoxy magnesium chloride; Alkoxy such as ethoxy magnesium, isopropoxy magnesium, butoxy magnesium, n-octoxy magnesium, 2-ethylhexoxy magnesium Magnesium; Aryloxymagnesium such as phenoxymagnesium, dimethylphenoxymagnesium Examples thereof include magnesium carboxylates such as magnesium laurate and magnesium stearate. Further, the magnesium compound having no reducing ability may be derived from the above-mentioned magnesium compound having reducing ability or may be one derived at the time of preparation of the catalyst component. For example, there may be mentioned a method in which a magnesium compound having a reducing ability is brought into contact with a compound such as a polysiloxane compound, a halogen-containing silane compound, a halogen-containing aluminum compound, an ester or an alcohol to convert it into a magnesium compound having no reducing ability. The magnesium compound may be a complex compound with another metal, a complex compound, or a mixture with another metal compound. Further, a mixture of two or more of these compounds may be used. Among these, preferred magnesium compounds are compounds having no reducing ability, and particularly preferred are halogen-containing magnesium compounds, especially magnesium chloride, alkoxymagnesium chloride, and allyloxymagnesium chloride.

In the present invention, the solid titanium catalyst component (A)
There are various titanium compounds used for the preparation of
Usually Ti (OR) _g X _4-g (R is a hydrocarbon group, X is a halogen,
A tetravalent titanium compound represented by 0 ≦ g ≦ 4) is preferable. 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} (O n -C 4 H 9) Cl 3, Ti (OC 2 H 5) B
_{r 3, Ti (OisoC 4 H} 9) trihalide, alkoxy titanium such as _{Br 3; Ti (OCH 3)} 2 Cl 2, Ti (OC 2 H 5) 2 Cl 2,
_{Ti (O n -C 4 H 9} ) 2 Cl 2, Ti (OC 2 H 5) 2 dihalogenated alkoxy titanium such as _{Br 2; Ti (OCH 3)} 3 Cl, Ti
_{(OC 2 H 5) 3 Cl} , Ti (O n -C 4 H 9) 3 Cl, Ti (OC
₂ H _{5) 3} monohalogenated trialkoxy titanium such as _{Br; Ti (OCH 3) 4} , Ti (OC 2 H 5) 4, Ti (O n -C
₄ H ₉₎ such as tetra-alkoxy titanium such as ₄ can be exemplified. Of these, preferred are halogen-containing titanium compounds, especially titanium tetrahalides,
Particularly preferred is titanium tetrachloride. These titanium compounds may be used alone or in the form of a mixture. Alternatively, it may be diluted with a hydrocarbon, a halogen hydrocarbon or the like.

In the preparation of the titanium catalyst component (A), a titanium compound, a magnesium compound, an electron donor to be supported, and an electron donor which may be optionally used, for example, alcohol, phenol, monocarboxylic acid ester. The amount of silicon compound, aluminum compound, etc. used varies depending on the preparation method and cannot be specified unconditionally. For example, 0.05 to 5 moles of electron donor to be supported per 1 mole of magnesium compound, 0.05 to 0.05 The ratio can be about 500 mol.

The halogen atom constituting the titanium catalyst component may be fluorine, chlorine, bromine, iodine or a mixture thereof, and chlorine is particularly preferable.

In the method of the present invention, the titanium solid catalyst component
When (A) contains an electron donor, a polymer having particularly excellent stereoregularity can be obtained by the polymerization method of the present invention.

In the present invention, the titanium solid catalyst component (A) as described above, an organometallic compound catalyst component of a metal of Groups 1 to 3 of the Periodic Table, for example, an organoaluminum compound catalyst component (B) and the below-mentioned components will be described. Olefin is polymerized or copolymerized using the combined catalyst of the component (C).

The organometallic compound catalyst component (B) of a metal of Groups 1 to 3 of the periodic table includes (i) an organoaluminum compound having at least one Al-carbon bond in the molecule, for example, the general formula R ¹ _m Al (OR ² ) _n H _p X _q (wherein R ¹ and R ² are carbon atoms, usually 1 to 15
Hydrocarbon groups containing one, preferably one to four, may be the same or different from each other. X is halogen, m is 0 <m ≦
3, n is 0 ≦ n <3, p is 0 ≦ p <3, and q is 0 ≦ q <3, and m + n + p + q = 3), (ii) a general formula M ¹ AlR ¹ ₄ (wherein M ¹ is Li, Na, a K, R ¹ is as defined above) alkylated complex of group 1 metal and aluminum represented by, (iii) the general formula R ¹ R ² M ² (wherein R ¹ and R ² are the same as above. M ² is Mg, Zn, C
and a dialkyl compound of a Group 2 metal represented by d).

Examples of the organoaluminum compound belonging to (i) above include the following. The 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.
5 ≦ m <3), the general formula R ¹ AlX _3-m (wherein R ¹ is the same as above, X is halogen, and m is preferably 0 <m <3), the general formula R ¹ AlH _3-m (wherein R ¹ is the same as above, m is preferably 2 ≦ m <3), the general formula R ¹ _m Al (OR ² ) _n X _q (wherein R ¹ and R ² are as described above). Same as, X is halogen, 0
<M ≦ 3, 0 ≦ n <3, 0 ≦ q <3, and m + n + q = 3).

In the aluminum compound belonging to (i), more specifically, trialkylaluminum such as triethylaluminum and tributylaluminum, trialkenylaluminum such as triisoprenylaluminum, dialkylaluminum such as diethylaluminum ethoxide and dibutylaluminum butoxide. Aluminum alkoxide, ethyl aluminum sesquiethoxide,
In addition to alkylaluminum sesquialkoxides such as butylaluminum sesquibutoxide, R ¹ _2.5 Al (OR ² )
_0.5 partially alkoxylated alkyl aluminum having an average composition represented by like, diethylaluminum chloride, dibutyl aluminum chloride, dialkyl aluminum halides such as diethyl aluminum bromide, ethyl aluminum sesquichloride, butyl aluminum sesquichloride, Alkyl aluminum sesquihalogenide such as ethyl aluminum sesquibromide, partially aluminum halide such as alkyl aluminum dihalogenide such as ethyl aluminum dichloride, propyl aluminum dichloride, butyl aluminum dibromide, diethyl aluminum hydride, Dialkyl aluminum hydrides such as dibutyl aluminum hydride, ethyl aluminum dihydride Partially hydrogenated alkylaluminums such as alkylaluminum dihydrides such as propyl aluminum dihydride, ethyl aluminum ethoxy chloride, butyl aluminum butoxycyclolide, partially alkoxylated and halogenated such as ethyl aluminum ethoxy bromide Alkyl aluminum.

The compound belonging to the above (ii) includes Li
Examples are Al (C ₂ H ₅ ) ₄ and LiAl (C ₇ H ₁₅ ) _4, and examples of the compound belonging to (iii) above include diethyl zinc and diethyl magnesium. Alkyl magnesium halides such as ethyl magnesium chloride can also be used. Among these, especially trialkyl aluminum,
It is preferable to use an alkylaluminum halide, a mixture thereof or the like.

The transition metal compound catalyst component (C) is a transition metal compound soluble in an inert organic medium, and is a compound of a metal of Group IVB of the periodic table such as titanium, zirconium and hafnium, and a metal such as vanadium and chromium. Examples thereof include compounds soluble in an inert medium, for example, halides such as chloride, bromide and iodide, alkoxides such as methoxide, ethoxide and propoxide. As these transition metal compounds, specifically, usually T
i (OR) _g X _4-g (R is a hydrocarbon group, X is a halogen, 0 ≦ g
≦ 4) are preferred. More specifically, titanium tetrahalides such as TiCl ₄ , TiBr ₄ , 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
Trihalogenated alkoxytitanium such as (OisoC ₄ H ₉ ) Br ₃ ; 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 alkoxy titanium such as _{Br 2; Ti (OCH 3)} 3 Cl, Ti (OC
_{2 H 5) 3 Cl, Ti} (O n -C 4 H 9) 3 Cl, Ti (OC 2 H 5) 3 Br
Monohalogenated trialkoxytitanium such as Ti; OC (OC
_{H 3) 4, Ti (OC} 2 H 5) 4, Ti (O n -C 4 H 9) 4 tetraalkoxy titanium or these and aluminum compounds such as, for example a mixture of other metal compounds of silicon compounds be able to. Of these, preferred are halogen-containing titanium compounds, especially titanium tetrahalides, and particularly preferred is titanium tetrachloride.

As the vanadium compound as the transition metal compound catalyst component, specifically, VOCl ₃ , VCl ₄ , VO
(OCH ₃ ) Cl ₂ , VO (OC ₂ H ₅ ) Cl ₂ , VO (OC
_{2 H 5) 1. 5 Cl} 1. 5, VO (OCH 3) 2 Cl, VO (OC 2 H 5) 3
And the like.

In the present invention, (A) a highly active titanium solid catalyst component containing magnesium, titanium and halogen as essential components, (B) an organometallic compound catalyst component of a metal of Group 1 to 3 of the periodic table, and In addition to (C) the transition metal compound catalyst component soluble in an inert organic medium, optionally (D) a catalyst component composed of an organosilicon compound or amines with large steric hindrance can be used.

Among the catalyst components [D] used in the present invention, the organic silicon compound generally has a Si--O--C or Si--N--C bond and is, for example, an alkoxysilane or an aryloxysilane. . As such an example, the formula R _n Si (OR ¹ ) _4-n (wherein 0 ≦ n ≦ 3,
R is a hydrocarbon group, such as an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, a haloalkyl group, an aminoalkyl group, or the like, or halogen, R ¹ is a hydrocarbon group,
For example, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, an alkoxyalkyl group, etc., provided that n R groups and (4-n) OR ¹ groups may be the same or different. )
And a silicon compound represented by the following formula: or,
Other examples include siloxanes having an OR ¹ group and silyl esters of carboxylic acids. or,
Other examples include compounds in which two or more silicon atoms are bound to each other via oxygen or nitrogen atoms. The above organosilicon compound is Si-O-
A compound not having a C bond and a compound having an O—C bond are preliminarily reacted with each other, or they are reacted at a polymerization site to give S
It may be used by converting it into a compound having an i-O-C bond. As such an example, for example, a halogen-containing silane compound or silicon hydride having no Si—O—C bond and an alkoxy group-containing aluminum compound, an alkoxy group-containing magnesium compound, other metal alcoholate, alcohol, formic acid ester, ethylene oxide, etc. A combination can be exemplified. The organosilicon compound may also contain other metals (eg, aluminum, tin, etc.).

More specifically, trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, t-butylmethyldimethoxysilane, t-
Butylmethyldiethoxysilane, t-amylmethyldiethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, bis-o-tolyldimethoxysilane, bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxy Silane, bis-p-tolyldiethoxysilane, bisethylphenyldimethoxysilane, dicyclohexyldimethoxysilane,
Cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane Methoxysilane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane, n-butyltriethoxysilane, iso-butyltriethoxysilane, phenyltriethoxysilane. Ethoxysilane, γ-aminopropyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, cyclohexyltrimethoxy Silane, cyclohexyltriethoxysilane, 2-norbornanetrimethoxysilane, 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriallyloxy silane , Vinyltris (β-methoxyethoxysilane), vinyltriacetoxysilane, dimethyltetraethoxydisiloxane, etc., among others, ethyltriethoxysilane, n-propyltriethoxysilane, t-butyltriethoxysilane, vinyltriethoxysilane, vinyltriethoxysilane, Ethenyltriethoxysilane, vinyltributoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, bis-p-tolyldimethoxysilane, p-tolylmethyldimethoxysilane, dicyclohexyl Sill dimethoxysilane, cyclohexylmethyl dimethoxysilane, 2- root Bol Nantes triethoxysilane, 2-norbornane methyl dimethoxy silane, diphenyl diethoxy silane, ethyl silicate are preferred.

As the amines having large steric hindrance, 2,2,6,6-tetramethylpiperidine, 2,2,5,
5-Tetramethylpyrrolidine, a derivative thereof, tetramethylmethylenediamine, or the like is preferable.
The component (D) can also be used in the form of other compounds and addition compounds.

In the polymerization method of the present invention, the catalyst component
When (D) is used, α- having 3 or more carbon atoms such as propylene
A polymer having particularly excellent stereoregularity can be obtained from olefin with higher activity.

The catalyst used in the olefin polymerization method of the present invention is α-in the presence of a catalyst formed from at least component (A), component (B), component (C) and optionally component (D).
It is an α-olefin prepolymerization catalyst obtained by olefin prepolymerization. In the method of the present invention, α-
The following method can be exemplified as a method of forming the olefin prepolymerization catalyst.

[1] A catalyst is formed by previously contacting the component (A), the component (B), the component (C) and optionally the component (D) in an inert medium, and then α-olefin. A method of forming an α-olefin prepolymerization catalyst by contacting with α-olefin prepolymerization catalyst.

[2] Component (A), component (B), component (C) and optionally component (D) in the presence of α-olefin, if necessary in an inert medium or in α-olefin medium. A method of forming an α-olefin prepolymerization catalyst by contacting in the solution.

[3] After the components (A), (B), (C) and optionally (D) are contacted with each other in advance to form a catalyst, they may be optionally mixed in an inert medium. Or α
A method of forming an α-olefin prepolymerization catalyst by contacting with α-olefin in an olefin medium.

In the method of the present invention, the component (A)
When the catalyst is formed by contacting the component (B), the component (C) and optionally the component (D) in the absence of α-olefin, the temperature during the contact treatment is usually -50 to 1
The temperature is 00 ° C., preferably −20 to 30 ° C., and the time required for the contact treatment is usually 1 minute to 10 hours, preferably 5 minutes to 2 hours. The contacting is optionally carried out in an inert medium in the absence of the components of α-olefin, and when contacted in the inert medium, the catalyst is formed in suspension. When the catalyst is formed in the form of a suspension, the catalyst suspension can be used as it is for the prepolymerization of α-olefin, and the formed catalyst can be separated from the suspension. Can be used for the prepolymerization of α-olefin.

In the method of the present invention, as described above, the component (A), the component (B),
By contacting the component (C) and optionally the component (D) in an inert medium or an α-olefin medium, if necessary, the catalyst formation and the α-olefin prepolymerization catalyst formation are carried out simultaneously or sequentially. Can be done.

In the method of the present invention, the component (A) during the formation of the catalyst or the α-olefin prepolymerization catalyst,
The ratios of the respective components of the component (B), the component (C) and optionally the component (D) are as follows: The ratio of the metal atom M ₁ of the component (B) is usually 1 gram atom of titanium of the component (A). Is in the range of 1 to 100 gram atoms, preferably 2 to 30 gram atoms, and the ratio of the transition metal atom M ₂ of the (C) component to 1 gram atom of titanium of the (A) component is usually 0.1 to 10. It is in the range of gram atom, preferably 0.4 to 3 gram atom, and the ratio of component (D) to 1 gram atom of titanium of component (A) is usually 0.3 to 30 moles, preferably 0.7 to 5 moles. It is in the molar range.

In the method of the present invention, the prepolymerization polymerizes 0.5 to 500 g, preferably 1 to 100 g, more preferably 2 to 10 g of α-olefin, per gram of the high activity titanium solid catalyst component (A). It is done by things. As the α-olefin used in the prepolymerization, ethylene and α-olefin having 3 to 20 carbon atoms, such as propylene, 1-butene, 4-methyl-1.
-Pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene and the like can be exemplified, but propylene is preferable.

The prepolymerization temperature is in the range of -20 ° C to 70 ° C, preferably -10 ° C to 60 ° C, more preferably 0 ° C to 50 ° C. The time required for the prepolymerization is usually 0.5 to 20 hours, preferably 1 to 10 hours.

The pre-polymerization can be carried out batchwise or continuously, and can be carried out either under normal pressure or under pressure. In the prepolymerization, a molecular weight modifier such as hydrogen may coexist, but at least 13
Intrinsic viscosity [η] measured in decalin at 5 ° C is 0.2 dl / g
The above amount is preferably 0.5 to 20 dl / g so that the amount of the prepolymer can be produced.

The prepolymerization is carried out without solvent or in an inert medium. Preliminary polymerization in an inert hydrocarbon medium is preferred from the viewpoint of operability. As the inert hydrocarbon medium used for the prepolymerization, the above-mentioned solvents can be exemplified.

In the prepolymerization, the concentration of the solid catalyst in the prepolymerization reaction system is usually 10 ^-6 to 1 gram atom / l, preferably 10 ^-4 to 10 ^-2 gram as the concentration of the transition metal atom in the solid catalyst. The range is atoms / l.

Inert media that may be used in the process of the present invention to form the catalyst or the α-olefin prepolymerization catalyst include ethane, propane, butane, pentane, methylpentane, hexane,
Examples thereof include aliphatic hydrocarbons such as heptane, octane, decane, gasoline, kerosene, and light oil, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, and aromatic hydrocarbons such as benzene, toluene, and xylene. It is also possible to use an inert medium consisting of a mixture of two or more of these. Similarly, examples of the α-olefin medium include α-olefins exemplified as α-olefins for prepolymerization.

In the method for polymerizing α-olefin of the present invention, the α-olefin prepolymerization catalyst is formed in a suspension state by the above-mentioned prepolymerization. The suspension can be used as it is, or the catalyst formed from the suspension can be used separately.

The α-olefin prepolymerization catalyst obtained by the above-mentioned prepolymerization exhibits excellent polymerization activity in the polymerization of α-olefin.

The olefins used for polymerization in the method of the present invention include ethylene, propylene, 1-butene, 4
-Methyl-1-pentene, 1-octene and the like, which can be subjected to not only homopolymerization but also random copolymerization or block copolymerization. Upon copolymerization, a polyunsaturated compound such as a conjugated diene or a non-conjugated diene can be selected as a copolymerization component. Of these olefins, propylene or 1-butene or 4-methyl-1
-Homopolymerization of pentene or a mixture of these olefins with other olefins such as propylene or 1-
It is preferable to apply the method of the present invention to the polymerization or copolymerization of mixed olefins containing butene as a main component (for example, 50 mol% or more, preferably 70 mol% or more).

In the process of the present invention, the olefin polymerization is carried out in the gas phase or in the liquid phase, for example in the form of a slurry. In slurry polymerization, an inert hydrocarbon may be used as a solvent, or olefin itself may be used as a solvent.

In the method of the present invention, the polymerization of α-olefin is carried out in the presence of the above α-olefin prepolymerization catalyst. In the polymerization reaction, it is possible to use only the above α-olefin prepolymerization catalyst, or in addition to the above α-olefin prepolymerization catalyst, any one of the components (B), (C) and (D) It can be carried out by adding two, three or three components.

In the method of the present invention, the proportion of each catalyst component present in the polymerization reaction system is T for the catalyst component (A).
It is about 0.001 to about 0.5 milligram atom / l, especially about 0.005 to about 0.5 milligram atom / l in terms of i atom, and for the catalyst component (B), the catalyst component ( For each gram atom of titanium atom in A),
About 1 to about 2000 grams of metal atoms in the component,
The amount is preferably in the range of about 5 to about 500 gram atom, and the catalyst component (D) has about 0.1 gram atom of titanium atom per 1 gram atom of titanium atom in the catalyst component (A).
To about 500 moles, preferably about 0.5 to 100
It is in the molar range.

In the polymerization reaction, when the catalyst component (B) is added to the above α-olefin prepolymerization catalyst to carry out the polymerization, the ratio of the component (B) is the titanium in the catalyst component (A). The metal atom in the component (B) is in the range of about 1 to about 2000 gram atom, preferably about 10 to about 500 gram atom per 1 gram atom of atom. Similarly, in addition to the above α-olefin prepolymerization catalyst, the catalyst component
When the polymerization is carried out by adding (D), the addition ratio of the component (D) is about 0 to 1000 mol, preferably about 0 to about 10 mol per 1 gram atom of titanium in the catalyst component (A).
It is in the range of 0 mol.

The olefin polymerization temperature is preferably about 20 to about 200 ° C., more preferably about 50 to about 180.
It is preferable to carry out under elevated pressure conditions of about 0 ° C. and pressure of about normal pressure to about 100 kg / cm ² , preferably about 2 to about 50 kg / cm ² . The polymerization can be performed by any of a batch system, a semi-continuous system, and a continuous system. Further, the polymerization can be carried out in two or more different stages under different reaction conditions.

[0073]

INDUSTRIAL APPLICABILITY In the present invention, particularly when applied to stereoregular polymerization of α-olefin having 3 or more carbon atoms,
A polymer having a high stereoregularity index can be produced with high catalyst efficiency. In relation to higher activity, the polymer yield per unit solid catalyst component is superior to the conventional proposals at the level of obtaining a polymer with the same stereoregularity index, so that It is possible to reduce the content of the catalyst residue, particularly the halogen content, and it is possible to omit the catalyst removal operation, and it is possible to significantly suppress the rusting tendency of the mold during molding.

[0074]

Next, the present invention will be described in more detail with reference to examples.

Example 1

[0076]

[Preparation of solid Ti catalyst component [A]] 7.14 g (75 mmol) of anhydrous magnesium chloride, 38 ml of decane and 35.1 ml (225 mmol) of 2-ethylhexyl alcohol were heated and reacted at 130 ° C. for 2 hours to form a uniform solution. To this solution was added 1.7 g (11.3 mmol) of phthalic anhydride, and the temperature was 130 ° C.
The mixture is further stirred and mixed for 1 hour to dissolve phthalic anhydride in the homogeneous solution. After cooling the homogeneous solution thus obtained to room temperature, titanium tetrachloride 2 kept at -20 ° C
The total amount is added dropwise into 00 ml (1.8 mol) over 1 hour. After completion of the charging, the temperature of the mixture was raised to 11 over 4 hours.
The temperature was raised to 0 ° C., and when it reached 110 ° C., 5.03 ml (18.75 mmol) of diisobutyl phthalate was added, and the mixture was maintained at the same temperature for 2 hours with stirring. After completion of the reaction for 2 hours, a solid part was collected by hot filtration, and this solid part was collected in 275 ml of T
After resuspending with iCl ₄ , heat reaction is performed again at 110 ° C. for 2 hours. After the completion of the reaction, the solid portion is again collected by hot filtration and thoroughly washed with decane and hexane at 110 ° C. until no free titanium compound is detected in the washing liquid. The catalyst component [A] is stored as a hexane slurry in the solid Ti synthesized by the above manufacturing method, and the slurry concentration of the catalyst is measured at the same time. The composition of the solid Ti catalyst component [A] obtained by drying a part of these was 2.4% by weight of titanium, 56% by weight of chlorine, 19% by weight of magnesium and 13.6% by weight of diisobutyl phthalate.

[0077]

[Pretreatment of Ti catalyst component [A]] 400 ml of a four-necked glass reactor equipped with a stirrer and purified hexane 100 in a nitrogen atmosphere.
ml, triethylaluminum 1.0 mmol, diphenyldimethoxysilane 2 mmol, the above solid Ti catalyst component
After the addition of 2.0 grams of [A] and 1 mmol of titanium tetrachloride, propylene was fed to the reactor at a temperature of 20 ° C. at a rate of 3.2 Nl / Hr for 1 hour. When the supply of propylene was completed, the inside of the reactor was replaced with nitrogen, and a washing operation was performed twice, which consisted of removing the supernatant and adding purified hexane, then resuspended in purified hexane and transferred to the catalyst bottle in its entirety. did. At this time, the measurement of the entire volume was also performed, and the slurry concentration of the catalyst was also measured.

[0078]

[Polymerization] Purified hexane 7 in an autoclave with an internal volume of 2 l
Charge 50 ml, and in a propylene atmosphere at 60 ° C., 0.75 mmol of triethylaluminum, 0.075 mmol of diphenyldimethoxysilane, and 0.0075 mmol of the titanium component in terms of titanium atom of the pretreatment product of the catalyst component [A]. (Corresponding to 10.9 mg in terms of [A]) was added. After introducing 200 ml of hydrogen, the temperature was raised to 70 ° C. and propylene polymerization was carried out for 2 hours. The pressure during polymerization is 7kg / cm
I kept it at ² G.

After completion of the polymerization, the slurry containing the produced polymer was filtered to separate it into a white powdery polymer and a liquid phase part. The yield of the white powdery polymer after drying was 232.3 g.
Extraction residual rate with n-heptane is 98.5%, MI is 5.
1. Its apparent density was 0.44 g / ml. On the other hand, 1.3 g of a solvent-soluble polymer was obtained by concentrating the liquid phase part. Therefore, the activity was 17,300 g-pp / g-catalyst, and II in all polymers was 98.0%.

Comparative Example 1 The same pretreatment operation as in Example 1 was carried out except that 1 mmol of titanium tetrachloride was not added in the pretreatment of the Ti catalyst component [A] in Example 1. The polymerization was carried out in the same manner as in Example 1. Table 1 shows the polymerization results.

Examples 2 to 5 Preliminary contact was carried out in the same manner as in Example 1 except that the amount of TiCl ₄ added as shown in Table 1 and the solvent at the time of preliminary contact were changed, and propylene was polymerized. Natsuta. The results are shown in Table 1.

Example 6 Pre-contact was carried out in the same manner as in Example 1 except that the feed rate and time of propylene during pre-contact were changed to 8 Nl / Hr and 4 hours, respectively, and propylene was polymerized. Was done. The results are shown in Table 1.

Example 7

[0084]

[Preparation of solid Ti catalyst component [A]] A high-speed stirrer (made by Tokushu Kika Kogyo) having an internal volume of 2 l was sufficiently replaced with N _2, and then 700 ml of refined kerosene, 10 g of commercially available MgCl ₂ and 24.2 g of ethanol and a trade name 3 g of EMAZOL 320 (Sorbitan distearate manufactured by Kao Atlas Co., Ltd.) was added, the temperature of the system was raised with stirring, and the mixture was stirred at 800 rpm for 30 minutes at 120 ° C. Under high speed stirring, a Teflon tube having an inner diameter of 5 mm was used to transfer the solution to a 2 liter glass flask (with a stirrer) filled with 1 liter of purified kerosene previously cooled to -10 ° C. The produced solid was collected by filtration and thoroughly washed with hexane to obtain a carrier.

After suspending 7.5 g of the carrier in 150 ml of titanium tetrachloride at room temperature, cyclohexanedicarboxylic acid dicarboxylic acid was suspended.
After adding 33 ml of n-octyl and stirring and mixing at 120 ° C. for 1.5 hours, the supernatant liquid was removed by decantation, and then the solid portion was suspended again in 150 ml of titanium tetrachloride, and again 1
The mixture was stirred and mixed at 30 ° C. for 1 hour. A reaction solid substance was collected from the reaction substance by filtration and washed with a sufficient amount of purified hexane to obtain a solid catalyst component [A]. The content of the components was 2.6% by weight of titanium, 60% by weight of chlorine, and 19% by weight of magnesium.

[0086]

[Pretreatment of Ti catalyst component [A]] Same as in Example 1 except that the Ti catalyst component [A] used in the pretreatment of Example 1 was changed from the Ti catalyst component of Example 1 to the above Ti catalyst component. Pretreatment was carried out by various methods, and propylene was polymerized. The results are shown in Table 2.

Comparative Example 2 In the pretreatment of the Ti catalyst component [A] in Example 7,
Pretreatment was carried out by the same method as in Example 7 except that 1 mmol of titanium tetrachloride was not added. The polymerization was carried out in the same manner as in Example 7. The polymerization results are shown in Table 2.

Example 8

[0089]

[Preparation of solid Ti catalyst component [A]] A 400 ml flask was charged with 6 g of flake Mg metal and 100 ml of n-hexane, washed at 68 ° C. for 1 hour and then dried with nitrogen. Next, 52 g of ethyl silicate was added and the mixture was heated to 65 ° C. and then 5 ml of methyl iodide
Add 0.1 ml of a solution of 1 g of iodine, and further add 50 ml of n-hexane.
A solution of 25 g of medium n-BuCl was added over 1 hour and the temperature of the mixture was kept at 70 ° C for 6 hours. After reaction 50
Washed 6 times using n-hexane at ℃. 7 g of the solid thus obtained was suspended in 100 ml of TiCl ₄ , 5.5 mmol of diisobutyl phthalate was added, and the mixture was reacted at 120 ° C. for 1 hour. Then, the supernatant was removed by decantation and the supernatant was removed again. 100 ml of TiCl ₄ was added and the reaction was carried out at 120 ° C. for 1 hour. After completion of the reaction, the solid Ti catalyst component [A] was prepared by sufficiently washing with hexane. The Ti catalyst component
The composition of [A] is 2.8% by weight titanium, 60% by weight chlorine, 19% by weight magnesium, and 1% diisobutyl phthalate.
1.3% by weight.

[0090]

[Pretreatment of Ti catalyst component [A]] Same as in Example 1 except that the Ti catalyst component [A] used in the pretreatment of Example 1 was changed from the Ti catalyst component of Example 1 to the above Ti catalyst component. Pretreatment was carried out by various methods, and propylene was polymerized. The results are shown in Table 2.

Comparative Example 3 In the pretreatment of the Ti catalyst component [A] in Example 8,
Pretreatment was carried out in the same manner as in Example 8 except that 1 mmol of titanium tetrachloride was not added. The polymerization was carried out in the same manner as in Example 8. The polymerization results are shown in Table 2.

Examples 9 to 12 In Example 7, the di-n-octyl cyclohexanedicarboxylate used in the preparation of the Ti catalyst component [A] was replaced with the electron donor shown in Table 3, and the Ti catalyst component [A] was used. Of the Ti catalyst component [A] was prepared in the same manner as in Example 7 except that the electron donor shown in Table 3 was used instead of the diphenyldimethoxysilane used in the pretreatment of [] and the polymerization of propylene. After pretreatment of the Ti catalyst component [A], propylene was polymerized. Table 3 shows the results.

Comparative Examples 4 to 7 Examples 9 to 12 except that TiCl ₄ was not added during the pretreatment of the Ti catalyst component [A] in Examples 9 to 12.
Prepolymerization was carried out in the same manner as described above to polymerize propylene. Table 3 shows the results.

[0094]

[Table 1]

[0095]

[Table 2]

[0096]

[Table 3]

[Brief description of the drawings]

FIG. 1 is a flow chart showing an example of a method for preparing a catalyst in the method for polymerizing α-olefin according to the present invention.

Claims (1)

[Claims] 1. A polyvalent compound obtained by pretreating a magnesium compound (A) with an alcohol having a carbon number of less than 8 and / or a halogen-containing silicon compound and reacting it with a titanium compound forming a liquid phase under reaction conditions. A highly active titanium solid catalyst component which is a magnesium, titanium, halogen and polycarboxylic acid ester essential component obtained by reacting a carboxylic acid ester and a titanium compound, (B) an organic group 1 to 3 metal of the periodic table Metal compound catalyst component, (C) Ti (OR) _g X _4-g soluble in an inert organic medium
(R is a hydrocarbon group, X is a halogen, and a tetravalent titanium compound represented by 0 ≦ g ≦ 4), and (D) the formula R _n Si (OR ¹ ) _4-n (wherein R and R ¹ are Alkyl group, cycloalkyl group, aryl group or alkenyl group, 0 ≦ n ≦ 3, where n is R and (4-n) is OR
^One group may be the same or different. Α-olefin is prepolymerized in the presence of a catalyst formed from the silicon compound represented by the formula (1), and α-olefin is polymerized in the presence of the resulting α-olefin prepolymerized catalyst. -Method for polymerizing olefins.