JPH02229805A - Method for polymerizing of olefin and catalyst therefor - Google Patents

Abstract

PURPOSE:To obtain a stereospecific polymer by (co)polymerizing olefin in the presence of catalyst composed of pre-polymerizing catalyst obtained by preliminary polymerization of olefin in the presence of specific catalyst, organic Al- compound catalyst component and organic silicon compound catalyst component. CONSTITUTION:Olefin is (co)polymerized in the presence of a catalyst for olefin polymerization composed of (A) a pre-polymerizing catalyst obtained by preliminary polymerization of olefin in the presence of a catalyst comprising (i) solid titanium catalyst component containing Mg, Ti, halogen and electron donor (e.g. diethyl succinate) as essential ingredients and (ii) halogen-containing organic aluminum compound catalyst component (e.g. dimethylaluminum chloride), (B) an organic aluminum compound catalyst component (e.g. triethylaluminum) and (C) an organic silicon compound catalyst component (e.g. trimethylmethoxysilane).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for polymerizing olefins that causes little decrease in catalyst activity during polymerization and allows polymerization to be carried out over a long period of time while maintaining activity, and to an olefin polymerization catalyst used in this polymerization.

Technical background of the invention and its problems There have already been many proposals regarding methods for producing solid catalyst components containing magnesium, titanium, halogen, and electron donors as essential components.
It is also known that a polymer having high stereoregularity can be produced in high yield by using it in the polymerization of the above α-olefin.

However, many of the solid catalyst components that have been proposed so far do not necessarily have sufficient properties such as catalytic activity or stereoregularity of the polymer, leaving room for further improvement.

For example, polyolefins produced using solid catalysts such as those described above are generally used without undergoing treatment to separate the catalyst after polymerization. In such stereoregular polyolefins, if the yield per unit amount of solid catalyst is low, the amount of catalyst remaining in the obtained polyolefin will be high and the quality of the polyolefin will be degraded.

Furthermore, polyolefins with a high solid catalyst content also have a relatively high halogen content, so from the perspective of preventing rust in molding equipment etc. due to residual halogen, it is necessary to reduce the amount per unit amount of solid catalyst. It is desirable that the yield is high.

Based on such requests, the applicant has so far
-Many methods have been proposed for the purpose of improving the problems of conventional techniques in the stereoregular polymerization of olefins (for example, JP-A-58-83006, JP-A-58-83006;
No. 38705, No. 511-138706, No. 5g-1
No. 38707, No. 5g-138708, No. 58-
No. 138709, No. 5B-138710, No. 5g-1
(Refer to each publication such as No. 38715).

Such publications include [A] a highly active titanium catalyst component containing magnesium, titanium, halogen, and an electron donor as essential components, [B] an organometallic compound catalyst component, and [C]
Catalysts formed from organosilicon catalyst components are described, and methods for polymerizing or copolymerizing olefins in the presence of such catalysts are described.

As a result of further studies on these catalysts, the present inventor used a specific halogen-containing organoaluminum compound as the organoaluminum compound catalyst component, and developed a catalyst consisting of the halogen-containing organoaluminium compound catalyst component and a titanium solid catalyst component. It was discovered that by using a prepolymerized catalyst obtained by prepolymerizing olefins in the presence of olefins, olefin polymers can be obtained with less decrease in catalyst activity during polymerization and maintaining activity for a long time. As a result, the present invention was completed.

Purpose of the Invention The present invention was completed in view of the above-mentioned points, and the present invention has been developed to provide a method for olefin polymerization that has little decrease in catalyst activity during polymerization and can be polymerized for a long period of time while maintaining activity. The object of the present invention is to provide a catalyst and a method for polymerizing olefins using the catalyst.

Summary of the Invention The olefin polymerization method according to the present invention comprises [A] (i
ii) a solid titanium catalyst component containing magnesium, titanium, a halogen, and an electron donor as essential components; (iii) a halogen-containing organoaluminum compound catalyst component; and (iii) an organosilicon compound catalyst component included as necessary. A prepolymerized catalyst obtained by prepolymerizing an olefin in the presence of a catalyst consisting of; [B] an organoaluminum compound catalyst component; and [C] an organosilicon compound catalyst component included as necessary. It is characterized by polymerizing or copolymerizing olefins in the presence of an olefin polymerization catalyst.

Further, the olefin polymerization catalyst according to the present invention has [A]
(iii) a solid titanium catalyst component containing magnesium, titanium, halogen, and an electron donor as essential components; (iii) a halogen-containing organoaluminum compound catalyst component; and (iii) an organosilicon compound catalyst component included as necessary. A prepolymerized catalyst obtained by prepolymerizing an olefin in the presence of a catalyst consisting of; [B] an organoaluminum compound catalyst component; and [C] an organosilicon compound catalyst component included as necessary. It is characterized by

As described above, the polymerization method of the present invention is carried out in the presence of a catalyst consisting of a solid titanium catalyst component [i], a halogen-containing organoaluminum compound catalyst component [i], and an organosilicon compound catalyst component [i] contained as necessary. Since a catalyst formed from a prepolymerized catalyst [A] obtained by prepolymerizing an olefin, an organoaluminum compound catalyst component [B], and an organosilicon compound catalyst component [C] contained as necessary is used. , there is little decrease in catalyst activity during polymerization, and olefins can be polymerized over a long period of time while maintaining activity.

DETAILED DESCRIPTION OF THE INVENTION The olefin polymerization method according to the present invention and the olefin polymerization catalyst used in this process will be specifically described below.

In the present invention, the term "polymerization" refers not only to homopolymerization, but also to
It is sometimes used to include copolymerization, and the term polymer is sometimes used to include not only homopolymers but also copolymers.

In the olefin polymerization method according to the present invention, olefin polymerization or copolymerization is carried out in the presence of an olefin polymerization catalyst as described below.

The catalyst for olefin polymerization according to the present invention includes a solid titanium catalyst component, a halogen-containing organoaluminum compound catalyst component (
a prepolymerized catalyst [A] obtained by prepolymerizing an olefin in the presence of a catalyst consisting of iii) and an organosilicon compound catalyst component (iii) included as necessary; and an organoaluminum compound catalyst component [B]. It is formed from an organosilicon compound catalyst component [C] included as necessary.

FIG. 1 shows an example of a flowchart of the method for preparing the catalyst used in the present invention.

First, the prepolymerization catalyst [A] used in the present invention will be explained. This prepolymerization catalyst [A] includes a solid titanium catalyst component (iii), a halogen-containing organoaluminum compound catalyst component (iii), and optionally a solid titanium catalyst component (iii). An olefin is pre-injected into a catalyst consisting of an organosilicon compound catalyst component (ii).
Obtained by polymerization.

The solid titanium catalyst component (1) used in the present invention is a highly active catalyst component containing magnesium, titanium, halogen, and an electron donor as essential components.

Such a solid titanium catalyst component (+) is prepared by contacting a magnesium compound, a titanium compound, and an electron donor as described below.

In the present invention, the titanium compound used for preparing the solid titanium catalyst component (iii) is, for example, Ti(O
R) X (R is a hydrocarbon group, X is 8g 4-
g rogene atom, and tetravalent titanium compounds represented by 0≦g≦4). More specifically, TiCl
) - TIBr - Tetrahalogenated titanium such as TII4; TI(OCH3)Cfl3, Tt(oC
2 a 5>c na,”rt(on-c4H9
) CfI3, T l(O C 2 H s > a r a, T I
Alkoxytitanium trihalogenides such as (O iso C a H 9 ) B r 3;
H5) Dihalogenated dialkoxytitanium such as 2Br2; Monohalogenated trialkoxytitanium such as TI(OCH3) 3Cρ, TI(QC2H5) 3(1, TI(On-C4H,) 8Cl, TI(QC2H5) 3Br; Ti( Examples include tetraalkoxytitaniums such as OCH3)4, TI(OC2H5)4, and Tl(on-C4Hta)4.

Among these, halogen-containing titanium compounds, particularly titanium tetrahalide, are preferred, and titanium tetrachloride is more preferred. These titanium compounds may be used alone or in combination of two or more. Furthermore, 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 (iii) include magnesium compounds having reducing properties and magnesium compounds not having reducing properties.

Here, as a magnesium compound having reducing properties,
For example, magnesium compounds having a magnesium-carbon bond or a magnesium-hydrogen bond can be mentioned. Specific examples of magnesium compounds having such reducing properties include dimethylmagnesium, diethylmagnesium, dibrobylmagnesium, dibutylmagnesium, diamylmagnesium, dihexylmagnesium, didecylmagnesium, ethylmagnesium chloride, probylmagnesium chloride, Examples include butylmagnesium chloride, hexylmagnesium chloride, amylmagnesium chloride, butyl ethoxymagnesium, ethylbutylmagnesium, and butylmagnesium halide. These magnesium compounds may be used alone, or may be used by forming a complex compound with an organoaluminum compound described below. Moreover, 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; methoxymagnesium chloride, ethoxymagnesium chloride, isobroboxymagnesium chloride, and butoxymagnesium chloride. , alkoxymagnesium halides such as octoxymagnesium chloride; alkoxymagnesium halides such as phenoxymagnesium chloride, methylphenoxymagnesium chloride; ethoxymagnesium,
isobroboxymagnesium, butoxymagnesium,
Alkoxymagnesiums such as n-octoxymagnesium and 2-ethylhexoxymagnesium; Allyloxymagnesiums such as phenoxymagnesium and dimethylphenoxymagnesium; Magnesium carboxylates such as magnesium laurate and magnesium stearate. be able to.

These non-reducing magnesium compounds may be compounds derived from the above-mentioned reducing magnesium compounds or compounds derived during the preparation of the catalyst component. In order to derive a magnesium compound that does not have reducibility from a magnesium compound that does, for example, a magnesium compound that has reducibility may be derived from a polysiloxane compound, a halogen-containing silane compound, a halogen-containing aluminum compound, an ester, an alcohol, etc. It is sufficient if the compound is brought into contact with the compound.

In addition, in the present invention, the magnesium compound includes, in addition to the above-mentioned reducing magnesium compounds and non-reducing magnesium compounds, complex compounds of the above-mentioned magnesium compounds with other metals, composite compounds, or other metal compounds. It may be a mixture. Furthermore, a mixture of two or more of the above compounds may be used.

In the present invention, among these, magnesium compounds that do not have reducing properties are preferred, and halogen-containing magnesium compounds are particularly preferred, and among these, magnesium chloride, alkoxymagnesium chloride,
Magnesium oxychloride is preferably used.

In the present invention, when preparing the solid titanium catalyst component (iii), it is preferable to use an electron donor, and examples of such electron donors include alcohols, phenols, ketones, aldehydes, carboxylic acids, and organic acids. Alternatively, oxygen-containing electron donors such as inorganic acid esters, ethers, acid amides, and acid anhydrides, nitrogen-containing electron donors such as ammonia, amines, nitriles, and isocyanates, and the like are used.

More specifically, methanol, ethanol, probanol, pentanol, hexanol, octanol, 2-
Alcohols with 1 to 18 carbon atoms such as ethylhexanol, dodecanol, octadecyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol, isobrobyl benzyl alcohol; phenol;
Cresol, xylenol, ethylphenol, probylphenol, cumylphenol, nonylphenol,
Phenols with 6 to 25 carbon atoms which may have an alkyl group such as naphthol; ketones with 3 to 15 carbon atoms such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetonephenone, benzophenone; acetaldehyde, propionaldehyde, Aldehydes having 2 to 15 carbon atoms such as octylaldehyde, benzaldehyde, tolualdehyde, and naphthaldehyde; methyl formate;
Ethyl acetate, vinyl acetate, probyl acetate, octyl acetate, cyclohexyl acetate, ethyl blobionate, methyl butyrate, ethyl valerate, ethyl stearate, methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, ethyl crotonate, dibutyl maleate, Diethyl butylmalonate, diethyl dibutylmalonate, ethyl cyclohexanecarboxylate, diethyl 1,2-cyclohexanedicarboxylate, di2-1,2-cyclohexanedicarboxylate
Ethylhexyl, methyl benzoate, ethyl benzoate, brovyl benzoate, butyl benzoate, octyl benzoate,
Cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate, ethyl ethylbenzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, dimethyl phthalate, diethyl phthalate, Organic acid esters having 2 to 30 carbon atoms such as dibutyl phthalate, dioctyl phthalate, γ-butyrolactone, δ-valerolactone, coumarin, phthalide, and ethylene carbonate; ethyl silicate, butyl silicate, vinyltriethoxysilane, Inorganic acid esters such as enyltriethoxysilane and diphenyldiethoxysilane; Acid halides with 2 to 15 carbon atoms such as acetyl chloride, penzoyl chloride, toluic acid chloride, anisyl chloride, and phthalic acid dichloride; methyl ether, ethyl ether , isobrobyl ether, butyl ether, amyl ether, tetrahydrofuran, anisole, diphenyl ether and other ethers having 2 to 20 carbon atoms; acid amides such as acetic acid amide, benzoic acid amide and toluic acid amide; benzoic anhydride; Acid anhydrides such as phthalic anhydride; amines such as methylamine, ethylamine, diethylamine, tributylamine, piperidine, tribenzylamine, aniline, pyridine, picoline, and tetramethylethylenediamine; nitrites such as acetonitrile, penzonitrile, trinitrile; etc. can be mentioned.

Among the above-mentioned electron donors, esters are preferable, and furthermore, those with the general formulas R4- and 100OR5 (where R1 is a substituted or unsubstituted hydrocarbon group, R2
R5RB is hydrogen or a substituted or unsubstituted hydrocarbon group, RR is hydrogen or a substituted or unsubstituted hydrocarbon group, and preferably at least one of them is a substituted or unsubstituted hydrocarbon group. Further, R3 and R4 may be connected to each other. The hydrocarbon group substituted for Rl-R5 above includes those containing different atoms such as N, O, and S, such as C-0-CSCOOR, COOH, OH,
It has groups such as SO H and -C-N-C- NH2. ) An ester having a skeleton represented by the following is preferably used.

Particularly preferred among these are polyhydric carboxylic acid esters in which at least one of R R2 is an alkyl group having 2 or more carbon atoms.

Specifically, such polyhydric carboxylic acid esters include diethyl succinate, dibutyl succinate, diethyl methylsuccinate, diisobutyl α-methylglutarate, dibutylmethyl malonate, diethyl malonate, diethyl ethylmalonate, and isopropylene. Diethyl vulmalonate, butyl diethyl malonate, phenyl diethyl malonate, diethyl diethyl manate, allyl diethyl malonate, diisobutyl diethyl malonate, di-n-butyl diethyl manate, dimethyl maleate, monooctyl maleate, maleic acid Dioctyl acid, dibutyl maleate, dibutyl butyl maleate, diethyl butyl maleate, β-
Aliphatic polycarboxylic acid esters such as diisopropyl methylglutarate, diallyl ethylsuccinate, di-2-ethylhexyl fumarate, diethyl itaconate, dibutyl itaconate, dioctyl citraconate, dimethyl citraconate, diethyl 1,2-cyclohexanecarboxylate,
1. Alicyclic polycarboxylic acid esters such as diisobutyl 2-cyclohexanecarboxylate, diethyl tetrahydrophthalate, diethyl nadic acid, monoethyl phthalate,
Dimethyl phthalate, methyl ethyl phthalate, monoisobutyl phthalate, mono-normal butyl phthalate, diethyl phthalate, ethyl isobutyl phthalate, ethyl normal-butyl phthalate, di-n-propyl phthalate, diisobutyl phthalate, phthalic acid Di-n-butyl, diisobutyl phthalate, di-n-hebutyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, dineopentyl phthalate, didecyl phthalate, benzylbutyl phthalate, diphenyl phthalate, naphthalene dicarbonate Examples include aromatic polycarboxylic acid esters such as diethyl acid, dibutyl naphthalene dicarboxylate, triethyl trimellitate, and dibutyl trimellitate, and heterocyclic polycarboxylic acid esters such as 3,4-furandicarboxylic acid.

Further, specific examples of the polyvalent hydroxy compound ester include 1,2-diacetoxybenzene, 1-methyl-2.
Examples include 3-diacetoxybenzene, 2,3-diacetoxynaphthalene, ethylene glycol diviparate, butanediol piperaate, and the like.

Specific examples of the hydroxy-substituted carboxylic acid ester include benzoylethyl salicylate, acetyl isobutyl salicylate, and acetyl methyl salicylate.

In addition to the above-mentioned compounds, examples of polycarboxylic acid esters include diethyl adipate, diisobutyl adipate, diisobutyl sebacate, dibutyl sebacate, di-n-octyl sebacate, and di-2 sebacate. -Esters of long chain dicarboxylic acids such as ethylhexyl can be used.

Among these polyfunctional esters, compounds having the skeleton of the general formula described above are preferred, and esters of phthalic acid, maleic acid, substituted malonic acid, etc. and alcohols having 2 or more carbon atoms are more preferred, and phthalic acid is particularly preferred. Diesters of acids and alcohols having 2 or more carbon atoms are preferred.

Other electron donors used in the present invention include RCOO
R'' (R., R' is a hydrocarbyl group which may have a substituent, at least one of which is a branched (including alicyclic) or ring-containing chain group) Examples include monocarboxylic acid esters.Specifically, R and R゜ are (CH)CH-C2H
5CH (CH3) (CH3) 2CHCH2-
(CH3) 3C-CH CH (CH3)CH
2 is used. If either R or R' is a group as described above, the other may be a -H group,
Alternatively, other groups such as linear or cyclic groups may be used.

Specifically, various monoesters such as dimethyl acetic acid, trimethyl acetic acid, α-methylbutyric acid, β-methylbutyric acid, methacrylic acid, and benzoyl acetic acid, various monocarboxylic acids of alcohols such as isopropanol, isobutyl alcohol, and tert-butyl alcohol. Acid esters are used.

Furthermore, carbonate ester can be used as the electron donor. Specifically, diethyl carbonate, ethylene carbonate, diisobrobyl carbonate, phenylethyl carbonate, diphenyl carbonate, etc. are used.

Two or more of these electron donors can be used in combination.

In the halogen-containing organoaluminum compound catalyst component (iii) and 17 used in preparing the prepolymerized catalyst,
A halogen-containing organic aluminum compound having at least one aluminum-carbon bond and a halogen in the molecule is used. Such a halogen-containing organoaluminum compound preferably has the following general formula [1al? In the formula, R1 and R2 are hydrocarbon groups, usually containing 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms, and they may be the same or different from each other. X
represents /X rogen atom, 0<m≦3, n is 0≦n<
3, p is a number such that O≦p<3, q is a number such that Q<q<3, and m+n+p+q-3) is used.

The above formula [I a. 1 is RR, and specifically, methyl group, ethyl group, n-probyl group,
Examples include isobrobyl group, butyl group, isobutyl group, sec-butyl group, and t-butyl group.

The expression above [! Among the halogen-containing organoaluminum compounds represented by the following general formula [1 t+] R1 AgX3...[I b]n (wherein R1 and X are the same as the formula [T al can be,
A halogen-containing organoaluminum compound represented by the following general formula [ 1 cl (wherein, R1 is the same as the formula [I a], and n is o A chlorine-containing organoaluminum compound represented by n<2) is used.

Specifically, the halogen-containing organoaluminum compound catalyst component (iii) represented by the above general formula [Ia] includes dialkyl aluminum such as dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride, and diethylaluminum bromide. halides, alkylaluminum sesquihalides such as ethylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide, alkylaluminum dihalides such as methylaluminum dichloride, ethylaluminum dichloride, probylaluminum dichloride, butylaluminum dichloride, butylaluminum dibromide etc. partial −
Partially alkoxylated and halogenated alkyl aluminums such as ethyl aluminum ethoxy chloride, butyl aluminum butoxy chloride, and ethyl aluminum ethoxy bromide can be mentioned.

More specifically, the halogen-containing organoaluminum compound represented by the above general formula [1b] includes dialkylaluminum halides such as methylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride, and diethylaluminum bromide, ethylaluminum sesquichloride, and butylaluminum chloride. Alkylaluminium sesquihalides such as aluminum sesquichloride, ethylaluminum sesquibromide, partially halogenated alkylaluminum dihalides such as methylaluminum dichloride, ethylaluminum dichloride, probylaluminum dichloride, butylaluminum dichloride, butylaluminum dibromide, etc. Alkylaluminum and the like can be mentioned.

More specifically, the halogen-containing organoaluminum compound represented by the above general formula [1c] includes methylaluminum chloride, diethylaluminum chloride,
Dialkyl aluminum chloride such as dibutyl aluminum chloride, ethyl aluminum sesquichloride,
Examples include alkyl aluminum sesquichlorides such as butyl aluminum sesquichloride. Further, in the present invention, an organosilicon compound catalyst component (ii) is used as necessary when preparing a prepolymerized catalyst.

Such an organosilicon compound catalyst component (iii) may be, for example, a compound of the following general formula [11l2 (wherein, n is 0≦n<4, and RR is a hydrocarbon group, such as an alkyl group or a cycloalkyl group. .

However, n R'(4-n) R2 may be the same or different. ) are preferably used.

Specifically, the organosilicon compound (iii) represented by the above general formula [11] includes trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyljethoxysilane, diisobuvirdimethoxysilane, t -butylmethyldimethoxsilane, t-butylmethyldiethoxysilane, t-amylmethyljethoxysilane, diphenyldimethoxysilane,
Phenylmethyldimethoxysilane, diphenyljethoxysilane, bis0-}lyldimethoxysilane, bis-
Tolyldimethoxysilane, p-tolyldimethoxysilane, bisp-tolyldiethoxysilane, bisethylphenyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, Vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane,
γ-chlorbutrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane, n-
Butyltriethoxysilane, Iso-butyltriethoxysilane, phenyltriethoxysilane, γ-aminopyltriethoxysilane, chlortriethoxysilane, ethyltriisoproboxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane Ethoxysilane, 2-norbornanetrimethoxysilane, 2-norbornanetriethoxysilane,
2-norbornanemethyldimethoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriaryloxysilane, vinyl 1-lis(β-methoxyethoxysilane) vinyltriacetoxysilane, dimethyltetraethoxysilane xydisiloxane, di-n-propyldimethoxysilane, di-t-butyldimethoxysilane, di-1-amyldimethoxysilane, dicyclohexylmethyldimethoxysilane, cyclopentylmethyldimethoxysilane, dicyclobentyldimethoxysilane, dicyclobentyldiethoxysilane, Di-n-propyldiethoxysilane, di-t-butyldiethoxysilane, cyclopentyltriethoxysilane, etc. are used.

Among these, ethyltriethoxysilane, n-propyltriethoxysilane, t-butyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane,
Vinyltributoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, bisp-}lyldimethoxysilane, 1)-Tolylmethyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, 2-norbornanetriethoxysilane, 2 - norbornanemethyldimethoxysilane, diphenyldiethoxysilane, di-n-propyldimethoxysilane, di-t-butyldimethoxysilane, di-t-amyldimethoxysilane, dicyclohexylmethyldimethoxysilane, cyclobentyldimethoxysilane, dicyclopentyldimethoxysilane, Preferred are dicyclopentyldiethoxysilane, di-n-propyldiethoxysilane, di[-butyldiethoxysilane, and cyclopentyltriethoxysilane.

In the present invention, the solid titanium catalyst component (1) can be produced by bringing the above-described magnesium compound (or metal magnesium), electron donor, and titanium compound into contact with each other.

In order to produce the solid titanium catalyst component (iii), a known method for preparing a highly active titanium catalyst component from a magnesium compound, a titanium compound, and an electron donor can be employed. Note that the above components may be brought into contact with each other in the presence of other reaction agents such as silicon, phosphorus, and aluminum.

Several examples of methods for producing these solid titanium catalyst components (iii) will be briefly described below.

(J,) A method of reacting a magnesium compound or a complex compound consisting of a magnesium compound and an electron donor with a titanium compound in a liquid phase. This reaction may be carried out in the presence of a grinding aid or the like.

Moreover, when reacting as described above, a solid compound may be pulverized.

(2) a liquid magnesium compound that does not have reducing properties;
A method in which a liquid titanium compound +y is reacted in the presence of an electron donor to precipitate a solid titanium complex.

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

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

(5) A solid material obtained by pulverizing a magnesium compound or a complex compound consisting of a magnesium compound and an electron donor in the presence of a titanium compound is treated with either a halogen, a halogen compound, or an aromatic hydrocarbon. How to process. In this method, the magnesium compound or the complex compound consisting of 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 consisting of a magnesium compound and an electron donor may be ground in the presence of a titanium compound, then pretreated with a reaction aid, and then treated with a halogen or the like. Note that examples of the reaction aid include organoaluminum compounds and halogen-containing silicon compounds.

(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 in which a contact reaction product of a metal oxide, dihydrocarbylmagnesium, and a halogen-containing alcohol is brought into contact with an electron donor and a titanium compound.

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

The solid titanium catalyst components (ii) listed in (1) to (8) above
Among the preparation methods i), a method using liquid titanium halide during catalyst preparation, a method using a halogenated hydrocarbon after using a titanium compound, or a method using a halogenated hydrocarbon when using a titanium compound are preferred.

The amount of each of the above-mentioned components used when preparing the solid titanium catalyst component (iii) varies depending on the preparation method and cannot be unconditionally defined, but for example, the amount of electron donor is about 0.01 per mole of magnesium compound. In an amount of ~5 mol, preferably 0.05-2 mol, the titanium compound is about 0
．． It is used in an amount of 0.01 to 500 mol, preferably 0.05 to 300 mol.

Solid titanium catalyst component (iii) thus obtained
contains magnesium, titanium, I\logen and an electron donor as essential components.

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

This solid titanium catalyst component (1) contains magnesium halide with a smaller crystal size compared to commercially available magnesium halide, and usually has a specific surface area of about 5Or+f.
/g or more, preferably about 60 to 1000 rT? /g, more preferably about 100 to 800 rrr/g. This solid titanium catalyst component (iii) is
Since the above components together form the catalyst component, its composition is not substantially changed by hexane washing.

Such a solid titanium catalyst component (iii) can be used alone, but it can also be used in combination with, for example, a silicon compound,
It can also be used after being diluted with an inorganic or organic compound such as an aluminum compound or polyolefin. Note that when a diluent is used, high catalytic activity is exhibited even if the specific surface area is smaller than the above-mentioned specific surface area.

Regarding the preparation method of such a highly active titanium catalyst component, see, for example, JP-A-50-108385 and JP-A-50-108385.
-126590, No. 51-20297, No. 51-28189, No. 51-f! No. 4586, No. 51-92885, No. 51-138f125
No. 52-87489, No. 52-1005
Publication No. 96, Publication No. 52-147688, Publication No. 52-1
No. 04593, No. 53-2580, No. 53-
No. 40093, No. 53-40094, No. 53
-43094, No. 55-135102, No. 55-185103, No. 55-152710, No. 5B-811, No. 5B-11908, No. 5B-18808, No. 58- No. 83006, No. 58-138705, No. 5g-13870
Publication No. 8, Publication No. 58-138707, Publication No. 58-13
No. 8708, No. 58-138709, No. 5g
-138710 publication, 58-138715 publication,
It is disclosed in 60-23404, 61-21109, 81-47802, 61,87803, etc.

In the present invention, the solid titanium catalyst component (iii
), halogen-containing organoaluminum compound catalyst component (i
A prepolymerized catalyst is prepared by prepolymerizing an olefin in the presence of a catalyst consisting of ii) and an organosilicon compound catalyst component (iii) included as necessary.

By performing such prepolymerization, a powder polymer with a high bulk density can be obtained, the polymer yield per unit catalyst amount is increased, and the stereoregularity of the obtained olefin polymer tends to be improved. It is in. In addition, if prepolymerization is performed, the properties of the slurry will be excellent in the case of slurry polymerization. Therefore, according to the polymerization method of the present invention,
The resulting polymer powder or polymer slurry can be easily handled.

In prepolymerization, the solid titanium catalyst component (
iii) is used in combination with the halogen-containing organoaluminum compound catalyst component (iii). At this time, an organosilicon compound catalyst component (iii) can also be allowed to coexist.

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

The concentration of the solid titanium catalyst component (iii) in the prepolymerization is usually in the range of about 0.01 to 200 mmol, preferably about 0.05 to 100 mmol, in terms of titanium atoms, per 1 g of the inert hydrocarbon medium described below. It is desirable to do so.

The amount of halogen-containing organoaluminum catalyst component (iii) is 0.1 to 5 per Ig of solid titanium catalyst component (iii).
00 g % Preferably, the amount may be such that 0.3 to 300 g of polymer is produced, and is usually about 0.1 to 1 mole of titanium atom in the solid titanium catalyst component (iii).
An amount of 100 moles, preferably about 0.5 to 50 moles is desirable.

Prepolymerization is preferably carried out under mild conditions by adding the olefin and the catalyst components described above to an inert hydrocarbon medium.

Examples of the inert hydrocarbon medium used at this time include aliphatic hydrocarbons such as propane, butane, bentane, hexane, hebutane, octane, decane, dodecane, and kerosene; cyclobentane, cyclohexane, methylcyclopentane, etc. Examples include 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, in the present invention, liquid α-
Olefins can also be used.

The olefin used in the preliminary polymerization may be the same as or different from the olefin used in the main polymerization described later.

When such an olefin is used in prepolymerization, a highly crystalline polymer can be obtained from an α-olefin having 2 to 10 carbon atoms, preferably 3 to 10 carbon atoms.

The reaction temperature for prepolymerization may be such that the prepolymer to be produced is not substantially dissolved in the inert hydrocarbon medium, and is usually about -20 to +100°C, preferably about -20°C.
It is desirable that the temperature is in the range of ~+80°C, more preferably 0~+40°C.

In addition, in the prepolymerization, a molecular weight regulator such as hydrogen can also be used. Such a molecular weight modifier is 1
To produce a prepolymer whose intrinsic viscosity [η] obtained by pre-Rm polymerization measured in decalin at 35°C is about 0.2 dN/g or more, preferably about 0.5 to 15 dll/g. It is best to keep the amount to a minimum.

Prepolymerization is carried out using titanium catalyst component (iii) as described above.
Approximately 0.1 to 1000. , preferably about 0.3
Preferably, ~500 g of polymer is produced. If the amount of prepolymerization is too large, the production efficiency of the olefin polymer in the main polymerization may decrease, and furthermore, when a film or the like is formed from the obtained olefin polymer, fish eyes may easily occur. .

Prepolymerization can be carried out batchwise or continuously.

In the present invention, the prepolymerized catalyst [A] prepared as described above, the organoaluminum compound catalyst component [B], and the organosilicon compound catalyst component [C
] Olefins are polymerized or copolymerized in the presence of an olefin polymerization catalyst formed from.

The organoaluminum compound catalyst component [B] used as a catalyst component in the main polymerization does not necessarily need to contain a halogen, and a compound having at least one aluminum-carbon bond in the molecule can be used. Such compounds include, for example, (wherein R1 and R2 usually have 1 to 15 carbon atoms,
Preferably it is a hydrocarbon group containing 1 to 4, and these may be the same or different from each other. X represents a halogen atom, 0 m≦3, n is 0≦n<3, p is 0≦p<3, q
is a number such that 0≦q<3, and m+n+p+q=3
(iii) an organoaluminum compound represented by the general formula M AI R' 4l (wherein M1 is Li, Na, K, and R1 is the same as above); Examples include complex alkylated products of.

Examples of the organoaluminum compound represented by the above general formula (iii) include the following compounds.

General formula R l! (OR2) l +18-m (in the formula, R1 and R2 are the same as above. m is preferably a number of 1.5≦m≦3), l general formula R /IX3-, (in the formula, Rl is the same as above. X is halogen, m is preferably 0<m<3), ■ General formula R l! H31 l (wherein R1 is the same as above. m is preferably 2≦m<3
), (wherein Rl and R2 are the same as above. X is halogen,
Ohm≦3, 0≦n<3, 0≦q<3, m+n+q-
Examples include compounds represented by 3).

More specifically, examples of the aluminum compound represented by the above general formula (iii) include 1-ethyl aluminum,
trialkylaluminum such as tributylaluminum; dryalkenylaluminum such as triisobrenylaluminum; dialkylaluminum alkoxide such as diethylaluminum ethoxide, dibutylaluminum butoxide; alkylaluminum sesquialkoxide such as ethylaluminum sesquiethoxide, butylaluminum sesquibutoxide, Partially alkoxylated alkylaluminum having a 2.5-0.5 average composition represented by R1 AD (OR ) etc.; dialkyl aluminum hydride such as diethylaluminum hydride, dibutyl aluminum hydride; ethyl aluminum dihydride, probyl aluminum Other partially hydrogenated alkylaluminums are used, such as alkylaluminum dihydrides such as dihydrides.

Compounds similar to (iii) include organoaluminum compounds in which two or more aluminum atoms are bonded via oxygen atoms or nitrogen atoms. Examples of such compounds include (C H ) A
R O/l (C2I{5) 2, (C H )
l OA! ! (C4H9) 2, C 2 H s methylaluminoxane, and the like.

As the compound represented by the above general formula (iii), L1
1 (C2H5) 4, Ll p. Examples include Il (c7H15) 4 and the like.

Among these, it is particularly preferable to use trialkylaluminum or alkylaluminum in which two or more of the above-mentioned aluminum compounds are combined.

Further, the organosilicon compound catalyst component [C] used as a catalyst component as necessary in the main polymerization includes the organosilicon compound used in preparing the prepolymerized catalyst as described above. Note that the organosilicon compound catalyst component (iii) used in preparing the prepolymerization catalyst and the organosilicon compound catalyst component [C] used in the main polymerization are not necessarily the same compound.

Olefins that can be used in this polymerization include ethylene, propylene, ■-butene, 4-methyl-
Examples include 1-bentene and -octene. In the polymerization method of the present invention, these olefins are used alone,
Or they can be used in combination. Among these olefins, it is preferable to carry out homopolymerization using propylene or 1-butene, or to carry out copolymerization using a mixed olefin containing propylene or 1-butene as a main component. When such mixed olefins are used, the content of propylene or l-butene, which is the main component, is usually 50 mol% or more, preferably 70 mol% or more.
It is preferable that it is mol% or more.

In the polymerization method of the present invention, a polymer having a high stereoregularity index can be produced with high catalytic efficiency by particularly polymerizing an α-olefin having 3 or more carbon atoms.

In addition, when performing homopolymerization or copolymerization of these olefins, compounds having polyunsaturated bonds such as conjugated dienes and non-conjugated dienes can also be used as polymerization raw materials.

In the polymerization method of the present invention, the main polymerization of olefin is usually carried out in a gas phase or a liquid phase.

When the main polymerization takes the reaction form of slurry polymerization, the above-mentioned inert hydrocarbon can be used as the reaction solvent, or an olefin that is liquid at the reaction temperature can also be used.

In the polymerization method of the present invention, the prepolymerization catalyst [A] is
Usually about 0.0 in terms of TI atoms per 1 g of polymerization volume.
05-0.5 mmol, preferably about 0.01-0.5
Used in millimolar amounts.

In addition, halogen-containing organoaluminum compound catalyst component (
iii) and organoaluminum compound catalyst component [B]
is usually about 1 to 200 aluminum metal atoms per mole of titanium atoms in the prepolymerization catalyst [A] in the polymerization system.
The amount used is such that it is 0 moles, preferably about 5 to 500 moles. Furthermore, organosilicon compound catalyst component [C]
is a halogen-containing organoaluminum compound catalyst component (i
ii) and per mole of aluminum atoms in the organoaluminum compound catalyst component [B] in terms of Sl atoms in the organosilicon compound catalyst component [C], usually about 0.001 to 1
It is desirable to use an amount of 0 mol, preferably about 0.01 to 2 mol, particularly preferably about 0.05 to 1 mol.

In the polymerization method according to the present invention, each catalyst component may be brought into contact with each other in an inert gas atmosphere or in an olefin atmosphere before polymerization.

If hydrogen is used during the main polymerization, the molecular weight of the resulting polymer can be adjusted and a polymer with a high melt flow rate can be obtained. Even in this case, in the polymerization method of the present invention, the stereoregularity index of the produced polymer does not decrease, nor does the catalytic activity decrease.

In the present invention, the polymerization temperature of the olefin is usually about 2
0-200°C, preferably about 50-180°C, the pressure is
Usually normal pressure to 100 kg/cj, preferably about 2 to 50
kg/cj. In the polymerization method of the present invention, polymerization can be carried out in any of the batch, semi-continuous and continuous methods. Furthermore, the polymerization can be carried out in two or more stages by changing the reaction conditions.

The olefin polymer thus obtained may be a homopolymer, a random copolymer, a block copolymer, or the like.

In the present invention, since the yield of a polymer having stereoregularity per unit amount of the solid catalyst component is high, the catalyst residue in the polymer, especially the halogen content, can be relatively reduced.

Therefore, the operation of removing the catalyst in the polymer can be omitted, and when molding a molded article using the produced olefin polymer, rusting of the mold can be effectively prevented.

In addition, since the catalyst according to the present invention exhibits sustained activity, it becomes easy to perform polymerization with different molecular weights at each stage in multistage polymerization, and it is possible to obtain a polymer with a wide molecular weight distribution.

Furthermore, since the activity can be maintained until the later stages of block copolymerization, a copolymer containing a large amount of hydrocarbon-soluble components can be easily obtained.

Effects of the Invention The olefin polymerization method of the present invention comprises the above-mentioned prepolymerization catalyst component [A], organoaluminum compound catalyst component [
Since the olefin is polymerized using a specific polymerization catalyst formed from the organosilicon compound catalyst component [B] and the organosilicon compound catalyst component [C] contained as necessary, there is little decrease in catalyst activity during polymerization, resulting in high activity. It is possible to polymerize olefins over a long period of time while maintaining the following properties, and to produce polyolefins with high stereoregularity in high yields.

The polyolefin obtained by the polymerization method of the present invention has a high bulk density.

Furthermore, the catalyst of the present invention can efficiently produce polyolefins having the above-mentioned excellent properties, and there is little decrease in catalyst activity with the passage of polymerization time.

As described above, since the catalyst according to the present invention can maintain polymerization activity for a long time, it becomes easy to perform polymerization with a difference in molecular weight at each stage in multistage polymerization, and to produce polymers with a wide molecular weight distribution. You can get a combination.

Furthermore, since the activity can be maintained until the later stages of block copolymerization, a copolymer containing a large amount of hydrocarbon-soluble components can be easily obtained.

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these examples.

Example 1 [Preparation of solid titanium catalyst component [A]] 7.14 g (75 mmol) of anhydrous magnesium chloride, 37.5 ml of decane, and 3 ml of 2-ethylhexyl alcohol 5. 1 ml (225 mmol) at 130℃
A heating reaction was carried out for 2 hours to form a homogeneous solution. after that,
1.67 g (it.a mmol) of phthalic anhydride was added to this solution, and the mixture was further stirred and mixed at 130° C. for 1 hour to dissolve phthalic anhydride into the above homogeneous solution.

After cooling the homogeneous solution thus obtained to room temperature, 200 ml of titanium tetrachloride kept at -20°C was added.
(1.8 mol) was added dropwise over 1 hour.

After dropping, the temperature of the obtained solution was raised to 110°C over 4 hours, and when it reached 110°C, diisobutyl phthalate 5. 0.3 ml (18.8 mmol) was added.

Stirred for an additional 2 hours at the above temperature. After 2 hours of reaction, a solid portion was collected by filtration while hot, and this solid portion was
After resuspending in 5 ml of TICI4,
The heating reaction was carried out at 0°C for 2 hours.

After the reaction was completed, the solid portion was collected again by hot filtration and heated to 110°C.
Washed with decane and hexane.

This cleaning was continued until no titanium compound was detected in the cleaning solution.

Solid titanium catalyst component [A] synthesized as above
was obtained as a hexane slurry.

A portion of this catalyst was collected and dried. Analysis of this dried material revealed that the composition of the solid titanium catalyst component [A] obtained as described above was 2.5% by weight of titanium and 58% by weight of chlorine.
% by weight, 18% by weight of magnesium and 13.8% by weight of diisobutyl phthalate.

[Prepolymerization] 200 ml of purified hexane was placed in a 400 ml glass reactor purged with nitrogen, and 20 mmol of diethylaluminum monochloride, 4 mmol of cyclohexylmethyldimethoxysilane, and the titanium catalyst component [A] were added. After adding 2 mmol in terms of titanium atoms, 11
．． Supplying propylene for 1 hour at a rate of 8 NfJ/hour,
3.5 g of propylene was polymerized per Ig of TI catalyst component [A].

After the preliminary polymerization was completed, the liquid portion was removed by filtration, and the separated solid portion was again dispersed in decane.

[Main polymerization] Purified hexane 7 50 in an autoclave with an internal volume of 2 g
ml of the prepolymerized product of 0.75 mmol of trimethylaluminum, 0.075 mmol of cyclohexylmethyldimethoxysilane, and the catalyst component [A] in a propylene atmosphere at room temperature to 0.75 mmol in terms of titanium atoms.
015 mmol (4.4 in terms of the catalyst component [A])
8s+H) was added. Then, the temperature was raised to 70°C,
Brobylene polymerization was carried out for 2 hours. The pressure during polymerization is 7
kg/c G.

After the polymerization was completed, the slurry containing the produced polymer was filtered and separated into a white granular polymer and a liquid phase. Table 1 shows the residual ratio extracted with boiling n-hebutane after drying, [η], apparent specific gravity, polymerization activity, II and particle size distribution of the total polymer.

Table 1 also shows the ratio of the polymerization rate 20 minutes after the start of polymerization to the polymerization rate 2 hours after the start of polymerization.

Comparative example 1. In the prepolymerization of Example 1, triethylaluminum was used instead of diethylaluminium monochloride, propylene was supplied at a rate of 5.9 NIl/hour for 1 hour, and 2.8 g of propylene was polymerized per 1 g of TI catalyst component [A1]. Polypropylene was polymerized in the same manner as in Example 1, except that

The results are shown in Table 1.

Example 2 [Preparation of solid titanium catalyst component [A]] A high-speed stirring device (manufactured by Tokushu Kika Kogyo ■) with an internal volume of 2 g was sufficiently replaced with N2, and 70Oml of refined kerosene and commercially available Mg were added.
210 g of C1, 24.2 g of ethanol, and 3 g of sorbitan distearate (trade name: Mazol 320, manufactured by Kao Atlas ■) were added, and the system was heated to 120 g with stirring.
The mixture was stirred at 800 rpm for 30 minutes at °C.

Separately, refine kerosene I in a glass flask with a capacity of 21 and equipped with a stirrer.
I was added and cooled to -10°C.

The above refined kerosene containing MgCff2 was transferred to 1 g of the above refined kerosene cooled to -10°C using a 5IIm Teflon tube.

The solid matter produced was collected by filtration, thoroughly washed with hexane, and
A carrier was produced.

7.5 g of the carrier obtained in this way was heated to 15
After suspending in 0 ml of titanium tetrachloride, 1.3 ml of diisobutyl phthalate was added and the temperature was raised to 120°C.

After stirring and mixing at 120°C for 2 hours, the solid part was collected by filtration.
The mixture was suspended again in 150 ml of titanium tetrachloride, and stirred and mixed again at 130° C. for 2 hours.

Then, the reaction solid was collected by filtration, and the reaction solid was washed with a sufficient amount of purified hexane to obtain a solid titanium catalyst component [A].

This solid titanium catalyst component [A] had a titanium content of 2.2% by weight, a chlorine content of 63% by weight, a magnesium content of 2 (lmJi%), and a diisobutyl phthalate content of 5.0% by weight in terms of atoms. .

[Prepolymerization] 200 ml of purified hexane was placed in a 400 ml glass reactor purged with nitrogen, and 20 mmol of triethylaluminum, 4 mmol of dicyclobentyldimethoxysilane, and the solid titanium catalyst component [A
] after adding 2 mmol in terms of titanium atoms, 11.8
Propylene was supplied at a rate of NII/hour for 1 hour, and 3.9 g of brobylene was polymerized per Ig of solid titanium catalyst component [A].

After prepolymerizing in this manner, the liquid portion was removed by filtration, and the solid portion collected by filtration was again dispersed in decane.

[Main polymerization] In the main polymerization of Example 1, solid titanium catalyst component [A]
Polymerization of brobylene was carried out in the same manner as in Example 1, except that the above catalyst was used.

The results are shown in Table 1.

Comparative Example 2 In the prepolymerization of Example 1, triethylaluminum was used instead of diethylaluminum monochloride, brobylene was supplied at a rate of 5.9NN/hour for 1 hour, and 3.0% per Ig of TI catalyst component [A] was added. Polymerization of polypropylene was carried out in the same manner as in Example 1, except that 0 g of propylene was polymerized.

The results are shown in Table 1.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing an example of a catalyst preparation method in the olefin polymerization method according to the present invention. -Table 1

Claims (1)

[Scope of Claims] 1) [A] Presence of a catalyst consisting of (i) a solid titanium catalyst component containing magnesium, titanium, halogen, and an electron donor as essential components, (ii) a halogen-containing organoaluminum compound catalyst component Below, an olefin is polymerized in the presence of an olefin polymerization catalyst formed from a prepolymerized catalyst obtained by prepolymerizing an olefin, [B] an organoaluminum compound catalyst component, and [C] an organosilicon compound catalyst component. Or a method for polymerizing olefins, characterized by copolymerization. 2) [A] Consists of (i) a solid titanium catalyst component containing magnesium, titanium, halogen, and an electron donor as essential components, (ii) a halogen-containing organoaluminum compound catalyst component, and (iii) an organosilicon compound catalyst component. Polymerizing or copolymerizing an olefin in the presence of an olefin polymerization catalyst formed from a prepolymerized catalyst obtained by prepolymerizing an olefin in the presence of a catalyst, and [B] an organoaluminum compound catalyst component. Characteristic olefin polymerization method. 3) [A] Consists of (i) a solid titanium catalyst component containing magnesium, titanium, halogen, and an electron donor as essential components, (ii) a halogen-containing organoaluminum compound catalyst component, and (iii) an organosilicon compound catalyst component. In the presence of an olefin polymerization catalyst formed from a prepolymerized catalyst obtained by prepolymerizing an olefin in the presence of a catalyst, [B] an organoaluminum compound catalyst component, and [C] an organosilicon compound catalyst component, An olefin polymerization method characterized by polymerizing or copolymerizing olefins. 4) [A] In the presence of a catalyst consisting of (i) a solid titanium catalyst component containing magnesium, titanium, halogen, and an electron donor as essential components, (ii) a halogen-containing organoaluminum compound catalyst component, an olefin is prepared in advance. An olefin polymerization catalyst formed from a prepolymerized catalyst obtained by polymerization, [B] an organoaluminum compound catalyst component, and [C] an organosilicon compound catalyst component. 5) [A] Consists of (i) a solid titanium catalyst component containing magnesium, titanium, halogen, and an electron donor as essential components, (ii) a halogen-containing organoaluminum compound catalyst component, and (iii) an organosilicon compound catalyst component. An olefin polymerization catalyst formed from a prepolymerized catalyst obtained by prepolymerizing an olefin in the presence of a catalyst, and [B] an organoaluminum compound catalyst component. 6) [A] Consists of (i) a solid titanium catalyst component containing magnesium, titanium, halogen, and an electron donor as essential components, (ii) a halogen-containing organoaluminum compound catalyst component, and (iii) an organosilicon compound catalyst component. An olefin polymerization catalyst formed from a prepolymerized catalyst obtained by prepolymerizing an olefin in the presence of a catalyst, [B] an organoaluminum compound catalyst component, and [C] an organosilicon compound catalyst component.