JPH0717695B2 - Method for producing catalyst carrier for olefin polymerization - Google Patents

Description

TECHNICAL FIELD The present invention relates to a process for producing a catalyst carrier for olefin polymerization,
More specifically, the present invention relates to a method for producing an olefin polymerization catalyst carrier capable of producing an olefin polymer having good stereoregularity and particle size characteristics and enhancing the catalytic activity of a supported metal.

[Prior Art and Problems Therefor] As a conventional olefin polymerization method, a solid catalyst obtained by reacting an electron-donating compound with a titanium halide on a carrier prepared by depositing magnesium dialkoxide on a metal oxide such as silica. A method using components is known (see JP-A-58-162607).

However, this method has a drawback that the particle size characteristics of the obtained polymer are insufficient because the deposition state of magnesium dialkoxide is insufficient.

In addition, after reacting silica or the like with an organosilicon compound,
A solid catalyst component in which a magnesium compound such as RMgX and an alcohol are sequentially reacted to form a carrier, and this is combined with titanium halide has also been proposed (Japanese Patent Publication No. 60-6962).
(See the official gazette).

However, in the method using this solid catalyst component, the hydroxyl group on the silica surface reacts with titanium halide, and the amount of effective titanium decreases, so that the catalyst activity per titanium is low and it cannot be put to practical use. There is.

[Object of the Invention] The present invention has been made based on the above circumstances.

That is, an object of the present invention is to provide a method for producing a carrier for an olefin polymerization catalyst, which has good stereoregularity and particle size characteristics of the obtained olefin polymer, and which conversely enhances the activity of the catalyst metal without inhibiting it. To do.

[Means for Solving the Problems] The outline of the present invention for solving the problems is the periodic table.
In a method for producing a catalyst carrier for olefin polymerization obtained from a solid oxide of at least one element selected from the elements belonging to groups II to IV and a magnesium compound, among elements belonging to groups II to IV of the periodic table A solid oxide of at least one element selected from the following and / or a solid composite inorganic oxide containing at least one of these solid oxides (hereinafter, these may be referred to as solid oxide components). And the following general formula R ₃ SiX (wherein R represents an alkyl group, a phenyl group and a vinyl group, and X reacts with a hydroxyl group present on the surface of the solid oxide and / or the solid composite inorganic oxide. A solid group (A) obtained by contacting a silane compound represented by the formula (1) with a magnesium alkoxide-containing liquid (B), and then mixed with a lower alcohol. The other is the preparation of an olefin polymerization catalyst carrier, which comprises adding a halogen compound (C).

Here, the solid oxide of an element belonging to periodic table II~IV group, for _{example, MgO, CaO, B 2 O} 3, SiO 2, SnO 2,
Al ₂ O _{3 and the} like, and as the solid composite inorganic oxide containing at least one of the solid oxides of the elements belonging to Groups II to IV of the periodic table, SiO ₂ -Al ₂ O ₃ , SiO ₂ −MgO, SiO ₂ −
_{TiO 2, SiO 2 -V 2 O} 5, SiO 2 -Cr 2 O 2, SiO 2 -TiO 2 -MgO and the like. These various solid oxides and solid composite inorganic oxides may be used alone or in combination of two or more of the solid oxides,
Two or more kinds of the solid composite inorganic oxides may be used together at the same time, or the solid oxide and the solid composite inorganic oxide may be used together at the same time.

Since this solid oxide component is a basic element of the catalyst carrier, if it is specified from the viewpoint of characteristics as a carrier, the non-surface area (BET method) is 10 to 800 m ² / g and the average particle size is 0.1 to 1000 μm.
Those in the range of m are desirable.

Among the solid oxide components, SiO ₂ which can have the above characteristics is preferable.

The silane compound has the following general formula R ₃ SiX (wherein R represents an alkyl group, a phenyl group and a vinyl group, and X is present on the surface of the solid oxide and / or the solid composite inorganic oxide). Represents a group capable of reacting with a hydroxyl group.

Specific examples of R in the general formula include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and a heptyl group, a phenyl group,
Examples thereof include a vinyl group, of which an alkyl group is preferable, and a methyl group is particularly preferable. Further, specific examples of X include, for example, a group capable of reacting with a hydroxyl group existing on the surface of the solid oxide and / or solid composite inorganic oxide, for example, a halogen atom such as —F, —Cl, or —Br. _{; -OCH 3 -OC 2 H 5,} -OC 3 H 5, -OC
_{4 H 7, -OC 6 H 5} , an alkoxy group, such as -OC ₆ H ₄ CH _3; -N
_{H 2, -NH (CH 3)} , - N (CH 3) 2, -NH (C 2 H 5), - N
(C ₂ H _{5) 2,} amino group, such as -NHSi (CH _{3) 3; Other, - (CH 2) 2 Cl} , - (CH 2) 3 Cl, - (CH 2) 3 N
_{H 2, -O 2 CCH 3,} - (CH 2) 3 SH , and the like, preferred are a halogen atom, particularly preferred is -Cl. The three R's in the general formula may be the same or different.

Among the above silane compounds, trimethylchlorosilane is preferable.

The amount of silane compound in contact with the solid oxide component,
It may be in excess with respect to the solid oxide component, and is usually 1 to 100 times mol, preferably 1 to 50 times mol of the Group II to IV elements of the periodic table.

The temperature at the time of contact between the solid oxide component and the silane compound is preferably in the range of 0 to 200 ° C. When the temperature at the time of contact is a high temperature such as 300 ° C,
Thermal decomposition of the silane compound may occur, which is not preferable.

The solid oxide component and the silane compound may be contacted as they are, or may be contacted in a hydrocarbon solvent such as hexane, heptane, benzene, toluene and xylene.

The contact time between the solid oxide component and the silane compound is usually 4 minutes to 12 hours. Also, the contact is
It is better to carry out under an inert gas atmosphere.

After the contact, the solid oxide component is preferably washed by decantation. This is because if the washing treatment is carried out, the subsequent contact with the magnesium alkoxide-containing liquid (B) can be favorably promoted. The above-mentioned hydrocarbon solvent can be used as the washing solvent.

In the method of the present invention, the solid material (A) obtained by contacting the solid oxide component with the silane compound is contacted with the magnesium alkoxide-containing liquid (B).

As the magnesium alkoxide-containing liquid (B),
A mixture of magnesium alkoxide and at least one selected from the group consisting of hydrocarbons, electron donors and alkoxytitanium can be preferably used.
Among the above hydrocarbons, electron donors and alkoxy titanium, alkoxy titanium is preferable.

Examples of the magnesium alkoxide include the general formula Mg (OR ¹ ) l (OR ² ) _2- l [wherein R ¹ and R ² are alkyl groups having 1 to 10 carbon atoms, cycloalkyl groups, aryl groups or It is an aralkyl group, R ¹ and R ² may be different from each other or may be the same, and l is a positive number from 0 to 2. ] Can be represented. Such magnesium alkoxide, _{e.g., Mg (-OCH 3) 2,} Mg (-OC
_{2 H 5) 2, Mg (} -OC 3 H 7) 2, Mg (-OC 6 H 5) 2, Mg (-O
_{C 6 H 13) 2, Mg} (-OC 8 H 17) 2, And preferred is dialkoxymagnesium.

Examples of the hydrocarbon include pentane, hexane,
Aliphatic hydrocarbons such as heptane, octane, decane, dodecane, tetradecane, kerosene, ligroin, petroleum ether; cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, cyclooctane,
Alicyclic hydrocarbons such as cyclohexene; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene, cymene; halogenated hydrocarbons such as dichloroethane, dichloropropane, trichloroethylene, carbon tetrachloride, chlorobenzene, etc. Can be mentioned. Of these, aliphatic hydrocarbons are preferable, and hexane, heptane, and octane are particularly preferable.

Further, as the electron donor, an aliphatic alcohol,
Aromatic alcohols, ethers, aldehydes, ketones, carboxylic acids, carboxylic acid anhydrides, acid halides, amines, amides, nitriles, isocyanates and the like can be mentioned. Among these, alcohols are preferable, and methanol, ethanol and the like are particularly preferable.

Examples of the alkoxytitanium include tetramethoxytitanium, tetraethoxytitanium, tetra-n-butoxytitanium, tetraisopropoxytitanium and the like, with tetra-n-butoxytitanium being particularly preferred.

The magnesium alkoxide-containing liquid (B) is prepared by
Magnesium alkoxides, hydrocarbons, electron donors,
Although different depending on the type of alkoxytitanium, it cannot be generally stated, but the method of mixing the magnesium alkoxide with any one or a mixture of the above hydrocarbons, electron donors and alkoxytitanium, or the method of mixing while heating, etc. Is mentioned.

As a preparation method, for example, (1) when alcohol and a hydrocarbon as an electron donor are used, the alcohol, the hydrocarbon and the magnesium alkoxide are mixed using about 1 mol or more of the alcohol per mol of the magnesium alkoxide. Method, and when (2) tetraalkoxytitanium is used, the amount of tetraalkoxytitanium is 0.5 mol or more, preferably 0.5 to 10 mol, and particularly preferably 0.5 to 5 mol, per 1 mol of magnesium alkoxide. There is a method of mixing tetraalkoxy titanium and magnesium alkoxide.

The magnesium alkoxide-containing liquid (B) thus obtained is brought into contact with the solid substance (A) at a temperature range of 0 to 100 ° C. for usually 5 minutes to 24 hours.

In the method of the present invention, a lower alcohol or a halogen compound (C) is added to a mixture obtained by contacting the magnesium alkoxide-containing liquid (B) and the solid substance (A) to obtain the solid substance (A). A magnesium compound can be deposited on the above.

The amount of the lower alcohol or halogen compound (C) added is sufficient to deposit the catalyst carrier for olefin polymerization.

It is not preferable to contact the magnesium alkoxide-containing liquid (B) and the lower alcohol or halogen compound (C) with the solid substance (A) at the same time.
This is because when the magnesium alkoxide-containing liquid (B) and the lower alcohol or halogen compound (C) are simultaneously added to the solid (A), the magnesium alkoxide reacts with the lower alcohol or halogen compound (C). This is because not only the catalyst carrier for olefin polymerization is adversely affected, but also the polymerization activity of the supported catalyst metal is reduced.

Examples of the lower alcohol include methanol, ethanol, propanol, butanol, pentanol and the like.

When the magnesium alkoxide-containing liquid (B) is prepared using tetraalkoxytitanium, the lower alcohol used is preferably an alcohol having an alkyl group having a carbon number smaller than that of tetraalkoxytitanium.

Examples of the halogen compound include silicon tetrachloride,
Trichlorosilane, monomethyldichlorosilane, dimethylchlorosilane, ethyldichlorosilane, n-propyldichlorosilane, vinyldichlorosilane, n-butyldichlorosilane, phenyldichlorosilane, benzyldichlorosilane, allyldichlorosilane. , Halosilanes such as monomethyl monochlorosilane, monoethyl monochlorosilane, trimethyl monochlorosilane, and monomethyl trichlorosilane; diethyl aluminum chloride, ethyl aluminum dichloride, ethyl aluminum sesquichloride, dimethyl aluminum chloride, methyl aluminum dichloride, methyl aluminum sesquichloride, propyl aluminum dichloride , Organo aluminum halides such as dipropyl aluminum chloride; Thionyl chloride; Chlorophos Arm, hexa-trichloroethane, carbon tetrachloride, carbon tetrabromide, iodide carbon, t-butyl chloride and halogenated hydrocarbons or halocarbons of; AlCl _3,
Examples thereof include metal halides such as AlBr ₃ , SnCl ₄ , BCl ₃ , SbCl ₃ and ZnCl ₂ ; hydrogen halides such as hydrogen chloride; and halogens such as chlorine. Among these, halosilane is preferable, and tetrachlorosilane is particularly preferable.

The olefin polymerization catalyst carrier obtained by this method,
A titanium compound is supported to form a solid catalyst component, and the solid catalyst component, the organometallic compound, and the electron donor for polymerization form an olefin polymerization catalyst.

The preparation of the solid catalyst component, the preparation of the olefin polymerization catalyst, and the polymerization of olefin by the olefin polymerization catalyst will be described below.

The solid catalyst component can be obtained by contacting the reaction product of the catalyst carrier for olefin polymerization obtained by the method of the present invention with the electron donor and the titanium compound.

Examples of the electron-donating substance include organic sulfonic acid ester, aliphatic carboxylic acid ester, and aromatic carboxylic acid ester.

As the titanium compound, those represented by the following general formula can be used.

Ti (OR ¹ ) _4- nXn (wherein R ¹ is an alkyl group having 1 to 10 carbon atoms,
It is a cycloalkyl group, an aryl group or an aralkyl group, n is a real number of 0 or more and 4 or less, and X represents a halogen atom. ) Specific examples of the titanium compound include TiCl ₄ , TiBr ₄ , and Ti.
Tetrahalogenated titanium such as I ₄ ; Ti (OCH ₃ ) Cl ₃ , Ti
Trihalogenated alkoxy titanium such as (OC ₂ H ₅ ) Cl ₃ , (n-C ₄ H ₉ O) TiCl ₃ , Ti (OC ₂ H ₅ ) Br ₃ ; Ti (OCH ₃ ) ₂ Cl ₂ ,, Ti
_{(OC 2 H 5) 2 Cl} 2, (n-C 4 H 9 O) 2 TiCl 2, Ti (OC 3 H 7) 2 Cl 2
Dihalogenated alkoxy titanium such as; Ti (OCH ₃ ) ₃ Cl, T
Examples include monohalogenated trialkoxy titanium such as i (OC ₂ H ₅ ) ₃ Cl, (n-C ₄ H ₉ O) ₃ TiCl, and Ti (OCH ₃ ) ₃ Br. These may be used alone or as a mixture. Of these, it is preferable to use a high halogen content substance, and it is particularly preferable to use titanium tetrachloride.

The reaction product of the olefin polymerization catalyst carrier, the electron donor and the titanium compound are usually contacted at 20 to 200 ° C, preferably 50 to 150 ° C for 0.5 to 10 hours, preferably 1 to 5 hours. Just go.

Further, a polyolefin can be obtained by bringing an olefin into contact with an olefin polymerization catalyst obtained from the solid catalyst component obtained as described above, an organometallic compound, and an electron donor for polymerization.

There are various kinds of organometallic compounds, and there is no particular limitation. Examples of the metal contained in this organometallic compound include lithium, sodium, potassium, zinc, cadmium, and aluminum, and aluminum is particularly preferable. The compound containing aluminum, that is, the organoaluminum compound, is not particularly limited and has the general formula AlR ³ mX _3- m (wherein, R ³ is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group or an aryl group). , M is a real number of 1 to 3, and X is a halogen atom such as chlorine or bromine).

Specific examples of the organoaluminum compound include trialkylaluminum such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum and diethylaluminum monochloride, diisopropylaluminum monochloride, diisobutylaluminum monochloride, dioctyl. Dialkylaluminum monohalides such as aluminum monochloride are preferable, and mixtures thereof are also preferable.

The electron donor for polymerization is an organic compound containing oxygen, nitrogen, phosphorus or sulfur. Specifically, amines, amides, ketones, nitriles, phosphines, phosphoramides, esters, ethers, thioethers, thioesters, acid anhydrides, acid halides, acid amides, organic acids , Aldehydes and the like.

More specifically, organic acids such as aromatic carboxylic acids such as benzoic acid and p-oxybenzoic acid; acid anhydrides such as succinic anhydride, benzoic anhydride and p-toluic anhydride; acetone, methyl ethyl ketone, Methyl isobutyl ketone,
C3 to C15 ketones such as acetophenone, benzophenone and benzoquinone; carbon number 2 such as acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, tolualdehyde and naphthaldehyde
~ 15 aldehydes; methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, ethyl butyrate, ethyl valerate, methyl chloroacetate, ethyl dichloroacetate,
Methyl methacrylate, ethyl crotonate, ethyl pivalate, dimethyl maleate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzoate Acid benzyl, methyl toluate, ethyl toluate, amyl toluate, ethyl ethyl benzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, ethyl p-butoxybenzoate, ethyl o-chlorobenzoate, ethyl naphthoate , Γ-butyrolactone, δ-valerolactone, coumarin, phthalide, ethylene carbonate and the like having 2 to 18 carbon atoms; acetyl chloride, benzyl chloride, toluic acid chloride, anisic acid chloride and the like having 2 to 2 carbon atoms
15 acid halides; methyl ether, ethyl ether,
Ethers having 2 to 20 carbon atoms such as isopropyl ether, n-butyl ether, amyl ether, tetrahydrofuran, anisole, diphenyl ether, ethylene glycol butyl ether; acid amides such as acetic acid amide, benzoic acid amide, toluic acid amide; tributylamine, N , N'-dimethylpiperazine, tribenzylamine, aniline, pyridine, picoline, amines such as tetramethylethylenediamine, nitriles such as acetonitrile, benzonitrile, tolunitrile; tetramethylurea, nitrobenzene, lithium butyrate, etc. You can Of these, preferred are esters, ethers, ketones, acid anhydrides and the like.
In particular, alkyl esters of aromatic carboxylic acids such as benzoic acid, p-methoxybenzoic acid, p-ethoxybenzoic acid, and toluic acid having 1 to 1 carbon atoms.
Alkyl esters of 4 are preferred, and aromatic ketones such as benzoquinone, aromatic carboxylic acid anhydrides such as benzoic anhydride, and ethers such as ethylene glycol butyl ether are also preferred.

This electron donor for polymerization may be the same as or different from the electron donor used in the preparation of the solid catalyst component.

As the composition of each component of the olefin polymerization catalyst, usually,
Organometallic compounds have a metal / titanium atomic ratio of 1 to 20
The amount is 00, preferably 5 to 1000, and for the electron donor for polymerization, the ratio of electron donor for polymerization (mol) / titanium (atom) is 0.01 to 500.

The olefin that can be polymerized by the olefin polymerization catalyst is represented by, for example, R ⁴ —CH═CH ₂ (wherein R ⁴ is hydrogen or an alkyl group or a cycloalkyl group having 1 to 20 carbon atoms). Can be, for example, ethylene, propylene, butene-1, pentene-1, octene-1,
Examples thereof include vinylcyclopentane and vinylcyclohexane, with ethylene and propylene being preferred.

As a method of polymerizing the olefin in the presence of the olefin polymerization catalyst, for example, a slurry polymerization method using an aliphatic hydrocarbon solvent, a bulk polymerization method, a gas phase polymerization method or the like can be adopted.

EFFECTS OF THE INVENTION According to the present invention, a solid oxide of at least one element selected from the elements belonging to Groups II to IV of the periodic table and / or at least one of these solid oxides is included. Since a solid substance (A) obtained by contacting a solid composite inorganic oxide with a specific silane compound is contacted with a magnesium alkoxide-containing liquid (B), a lower alcohol or a halogen compound (C) is added. (1) The particle size of the obtained olefin polymer is uniform, and therefore, the clogging of the pipe during the transportation of the olefin polymer can be eliminated, and the stereoregularity of the obtained olefin polymer can be improved. It is possible to form a catalyst, and (2) to provide a catalyst carrier for olefin polymerization, which can enhance the catalytic activity of a supported metal. You can

EXAMPLES Next, the present invention will be described more specifically by showing examples of the present invention.

(Example 1) Preparation of catalyst support for olefin polymerization In a glass container of 0.5 in which argon was substituted, calcined silicon oxide (Fuji Davison, grade 952, specific surface area 350)
35 g of m ² / g and average particle size of 54 to 65 μm) and 175 ml of trimethylchlorosilane were added. The mixture was reacted under reflux for 12 hours while stirring. After that, n-heptane 100m
Washing by decantation was repeated 3 times using 1 to obtain a solid.

Then, diethoxy magnesium 150mmo
l, an n-heptane solution containing 50 mmol of tetra-n-butoxytitanium was added, and the mixture was contacted at room temperature for 1 hour.

Then, 50 ml of isopropanol was added dropwise. And 80
After stirring at 0 ° C for 1 hour, decantation was repeated 5 times with 100 ml of n-heptane. 80 after decantation
By drying under reduced pressure at 0 ° C. for 1 hour, a white solid catalyst carrier for olefin polymerization was obtained. The catalyst carrier for olefin polymerization contained 3.1% by weight of magnesium metal.

Preparation of solid catalyst component for olefin polymerization 8.0 g of a catalyst carrier for olefin polymerization obtained as described above
The mixture was placed in a glass container of 0.5 and 50 ml of n-heptane, 3.6 mmol of ethyl benzoate and 40 g of titanium tetrachloride were placed.
The mixture was stirred under reflux for 1 hour. Then, the supernatant was removed by decantation, and the obtained solid portion was sufficiently washed with hot n-heptane to obtain a solid catalyst component for olefin polymerization. The titanium content in the solid catalyst component for olefin polymerization was 2.4% by weight.

Polymerization of Propylene 0.006 mg atom (in terms of titanium atom) of the solid catalyst component suspended in 50 ml of hexane in an autoclave purged with argon and 1.5 mmol of triisobutylaluminum.
And 0.45 mmol of methyl p-toluate were added. After depressurizing the inside of the autoclave to remove argon, 310 g of propylene and 0.7 N of hydrogen were charged into the autoclave. After 5 minutes, raise the temperature to 70 ° C,
Polymerization was carried out for a time.

After cooling the autoclave, propylene was purged and the contents were taken out. Dry the contents under reduced pressure to 99
g polypropylene powder was obtained. The ratio of boiling n-heptane extraction residual polymer of this powder (II) was 97.3.
%Met. The bulk density of this powder is 0.38g / cm.
³ and the fine powder of 100 μm or less was 0.1% by weight.

(Comparative Example 1) The same as Example 1 except that trimethylchlorosilane was not used.
An olefin polymerization catalyst carrier was prepared in the same manner as in 1., and a solid catalyst component and a catalyst were prepared in the same manner as in Example 1, and propylene was polymerized.

The obtained polypropylene powder was 9.1 g, and II was
It was 97.0%.

Comparative Example 2 The same procedure as in Example 1 was repeated except that methyltrichlorosilane was used instead of trimethylchlorosilane and butylethylmagnesium was used instead of diethoxymagnesium.

The obtained polypropylene powder was 48 g, its bulk density was 0.35 g / cm ³ , fine powder of 100 μm or less was 0.3% by weight, and the polymer II was 95.8%.

(Example 2) The same procedure as in Example 1 was carried out except that ethanol was used as the precipitant instead of isopropanol.

The obtained polypropylene powder was 103 g, its bulk density was 0.38 g / cm ³ , and fine powder of 100 μm or less was 0% by weight.
And the polymer II was 97.3%.

(Example 3) Isopropanol, which is a precipitating agent, was added to tetrachlorosilane 30.
The same procedure as in Example 1 was performed except that the amount was replaced with ml.

The obtained polypropylene powder was 120 g, its bulk density was 0.44 g / cm ³ , fine powder of 100 μm or less was 0.2% by weight, and the polymer II was 97.0%.

(Comparative Example 3) The same procedure as in Example 1 was performed except that n-heptane was distilled off under reduced pressure without using isopropanol as a precipitant.

The obtained polypropylene powder is 72 g, its bulk density is 0.25 g / cm ³ , and fine powder of 100 μm or less is 25% by weight.
And the polymer II was 96.8%.

[Brief description of drawings]

FIG. 1 is a flow chart showing steps of producing the catalyst according to the present invention.

Claims (1)

[Claims] 1. A process for producing an olefin polymerization catalyst carrier obtained from a magnesium compound and a solid oxide of at least one element selected from elements belonging to Groups II to IV of the periodic table, Solid oxides of at least one element selected from elements belonging to groups II to IV and / or solid complex inorganic oxides containing at least one of these solid oxides and the following general formula R ₃ SiX In the formula, R represents an alkyl group, a phenyl group and a vinyl group, and X represents a group capable of reacting with a hydroxyl group existing on the surface of the solid oxide and / or the solid composite inorganic oxide.). A solid (A) obtained by contacting with a silane compound is mixed with a magnesium alkoxide-containing liquid (B), and then a lower alcohol or a halogen compound (C) is added. Preparation of olefin polymerization catalyst carrier characterized by and.