JP2647694B2 - Method for producing branched α-olefin polymer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a branched α-olefin polymer, and more particularly, to a method for producing a branched α-olefin polymer having excellent properties such as stereoregularity. The present invention relates to a method for efficiently and stably producing a product by a simple process.

Technical background of the invention and its problems In the presence of a Ziegler polymerization catalyst containing a titanium trihalide component, 4-methyl-1-pentene and 3-methyl-1
-Homopolymerize a branched α-olefin such as pentene or copolymerize a branched α-olefin with another olefin to produce a branched α-olefin polymer having excellent transparency and heat resistance. Many attempts have been made so far.

However, the branched α-olefin-based polymer obtained in the presence of such a titanium trihalide catalyst has a wide molecular weight distribution and excellent melt fluidity and moldability, but has stereoregularity and rigidity. In addition, there is a problem that the catalyst is inferior in polymerization activity. Accordingly, the present applicant has disclosed a method of polymerizing a branched α-olefin in the presence of a catalyst formed from a highly active titanium catalyst component, an organoaluminum compound catalyst component and an organosilicon compound catalyst component, as disclosed in JP-A-59-206418. Suggested.

By the way, various methods are known as a method for polymerizing the branched α-olefin. For example, a suspension polymerization method in which a branched α-olefin which is a monomer is dispersed in a monomer-insoluble medium and a polymerization reaction is carried out in a liquid phase to obtain a polymer as a solid dispersion in the liquid phase, a monomer and a produced polymer A solution polymerization method in which a monomer is dissolved in a medium in which both can be dissolved and a polymer obtained by performing a polymerization reaction is obtained as a solution dissolved in the medium, or a gas phase polymerization method in which the monomer is polymerized under a gas phase condition, is used. Are known.

Each of these polymerization methods has advantages and disadvantages.

For example, the above suspension polymerization method is a method excellent in economy, but when this method is used, a homopolymerization reaction of a branched α-olefin or a branched α-olefin and a linear α-olefin When the polymerization temperature is increased when performing a copolymerization reaction with or when the latter is used in a large amount relative to the former when performing a copolymerization reaction between a branched α-olefin and a linear α-olefin. In addition, the produced polymer tends to be dissolved in a medium in an increased amount.

In such a case, even if the reaction solution in which the produced polymer is dissolved is to be separated into the polymer and the mother liquor by a separator, the mother liquor contains a large amount of the dissolved polymer, and There was a problem that the collection efficiency was poor. Further, the mother liquor containing a large amount of the polymer dissolved in this way has a high viscosity, and when the mother liquor is circulated to the polymerization vessel A and reused, the mother liquor circulating pump G as shown in FIG. When the mother liquor is cooled by a mother liquor discharge line 3 from the separator E to the mother liquor drum F or a mother liquor circulation line 4 from the mother liquor drum F to the polymerization unit A via the mother liquor circulation pump G, There has been a problem that the dissolved polymer precipitates in the mother liquor drum or in the line, adheres to these inner walls, and causes blockage of the line.

In such a case, it is not economical to provide a special device for separating the polymer dissolved in the mother liquor after the conventional separator E to circulate and reuse the mother liquor.

Object of the Invention The present invention is intended to solve the problems associated with the prior art as described above, and has the following objects.

That is, the present invention provides a method for efficiently and at a high recovery of a branched α-olefin polymer from a polymer solution containing a branched α-olefin polymer obtained by polymerizing a branched α-olefin. It is intended to provide.

Further, the present invention reduces the amount of polymer remaining and dissolved in the mother liquor by recovering the polymer thus produced at a high recovery rate, and reduces the amount of the polymer dissolved in the mother liquor. Precipitation / polymerization of polymer in the mother liquor discharge line from inside or from the separator to the mother liquor drum, and in the mother liquor circulation line from the mother liquor drum to the polymerizer via the mother liquor circulation pump
The purpose is to reduce fouling, prevent line blockage, and enable stable operation of these devices.

SUMMARY OF THE INVENTION The method for producing a branched α-olefin polymer according to the present invention comprises the steps of: producing a branched α-olefin polymer in a polymerization vessel in the presence of a catalyst in a polymerization vessel; Polymerization is performed in a liquid phase, and a polymer solution containing the obtained polymer is introduced into a cooler and cooled, thereby precipitating a polymer dissolved in the polymer solution. A polymer solution containing is introduced into a separator to separate a polymer formed and an unreacted branched α-olefin, and the polymer is recovered and the separated branched α-olefin is introduced into the polymerizer. It is supplied and reused.

In such a method for producing a branched α-olefin-based polymer according to the present invention, the branched α-olefin-based polymer can be efficiently recovered at a high recovery rate. In addition, the branch α-
The mother liquor after the olefin polymer has been recovered contains a small amount of the remaining dissolved polymer, so the mother liquor discharge line from the separator, the mother liquor drum, the mother liquor pump, or other equipment or the separator to the mother liquor drum In the mother liquor circulation line from the mother liquor drum to the polymerization vessel through the mother liquor circulation pump, the polymer is less likely to be deposited and adhered, so that the line is less likely to be clogged, and stable operation of these devices is possible. Become.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, a method for producing a branched α-olefin polymer according to the present invention will be specifically described.

In the present invention, a catalyst is used for homopolymerizing a branched α-olefin or copolymerizing a branched α-olefin and a linear α-olefin in a polymerization vessel.

As such a catalyst, for example, a so-called Ziegler catalyst can be used. Among them, (A) a highly stereoregular titanium catalyst component containing magnesium, titanium, halogen and an electron donor as essential components; A catalyst formed from an organoaluminum compound catalyst component and (C) an electron donor component is preferably used.

The highly stereoregular titanium catalyst component (A) contains magnesium, titanium, halogen, and an electron donor as essential components. Such a titanium catalyst component (A) preferably has a magnesium / titanium (atomic ratio) of about 2 to 100,
More preferably about 4 to 70, the halogen / titanium (atomic ratio) is preferably about 4 to 100, more preferably about 6 to 40, and the electron donor / titanium (molar ratio) is preferably about 0.2 to 10, more preferably in the range of about 0.4 to 6.

The specific surface area of the highly stereoregular titanium catalyst component (A) is preferably about 3m ² / g or more, more preferably about 40 m ² / g or more, particularly preferably about 100m ² / g~8000m ² / g Is desirable.

Such a titanium catalyst component (A) generally does not substantially desorb a titanium compound even if it is simply washed with hexane at room temperature.

Regardless of the starting magnesium compound used for preparing the catalyst, the X-ray spectrum of such a titanium catalyst component (A) shows an amorphous property, or is extremely different from that of a general commercial product of magnesium dihalide. Desirably, it is in an amorphous state.

The titanium catalyst component (A) may contain other elements, metals, functional groups, and the like, in addition to the essential components, as long as the catalyst performance is not significantly deteriorated. Further, it may be diluted with an organic or inorganic diluent.

As described above, when the titanium catalyst component (A) contains other components, for example, other elements, metals, diluents, and the like, the titanium catalyst component (A) is removed when such other components are removed. It is preferable to exhibit the specific surface area value as described above and to exhibit amorphousness.

The titanium catalyst component (A) generally has an average particle diameter of about 1 to 1.
It is desirably 200 μm, preferably about 5 to 100 μm, and the geometric standard deviation σg of the particle size distribution is usually less than 2.1, preferably 1.95 or less. Further, the particle shape is preferably a regular shape such as a true spherical shape, an elliptical spherical shape, and a granular shape.

To produce the titanium catalyst component (A), a magnesium compound (or magnesium metal), a titanium compound and an electron donor or an electron donor-forming compound (a compound forming an electron donor) are used by using another reaction reagent. These may be brought into contact with each other without using them.

The production of the titanium catalyst component (A) may be performed according to a conventionally known method for preparing a highly active titanium catalyst component containing magnesium, titanium, a halogen and an electron donor as essential components.

The method for preparing such a highly active titanium catalyst component is described in, for example, JP-A-50-108385, JP-A-50-126590, and JP-A-50-126590.
Nos. 51-20297, 51-28189, 51-64586, 51-92885, 51-136625, and 52.
No. 87489, No. 52-100596, No. 52-147688, No. 52-104593, No. 53-2580, No. 53-
No. 40093, No. 53-43094, No. 55-135102, No. 55-135103, No. 56-811, No. 56-119
No. 08, No. 56-18606, No. 58-83006,
JP-A-58-138705, JP-A-58-138706, JP-A-58-138707
JP-A-58-138708, JP-A-58-138709,
It is disclosed in JP-A-58-138710 and JP-A-58-138715.

The production method of these titanium catalyst components (A) will be briefly described below with several examples.

(1) A method of reacting a magnesium compound or a complex compound comprising a magnesium compound and an electron donor with a titanium compound in a liquid phase.

This method may be performed in the presence of an electron donor, a grinding aid, and the like.

Further, when reacting as described above, the solid compound may be pulverized.

Furthermore, when performing the reaction as described above, a preliminary treatment with an electron donor and / or a reaction auxiliary such as an organoaluminum compound or a halogen-containing silicon compound may be performed.

In any case, in this method, the electron donor is used at least once.

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

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

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

(5) A solid compound obtained by pulverizing a magnesium compound or a complex compound comprising a magnesium compound and an electron donor in the presence of a titanium compound is treated with any of a halogen, a halogen compound and an aromatic hydrocarbon. how to.

In this method, a magnesium compound or a complex compound of a magnesium compound and an electron donor may be pulverized in the presence of an electron donor, a pulverization aid, and the like.

Further, a magnesium compound or a complex compound composed of a magnesium compound and an electron donor is pulverized in the presence of a titanium compound, and then pre-treated with an electron donor and / or a reaction aid, and then treated with a halogen or the like. Is also good. In addition, examples of the reaction assistant include an organic aluminum compound and a halogen-containing silicon compound.

In any case, in this method, an electron donor is used at least once.

In the method for preparing the titanium catalyst component (A) described in the above (1) to (5), when at least one of the magnesium compound and the titanium compound contains a halogen atom, the halogen-containing silicon compound or It is not necessary to use a halogenating agent such as a halogenated organoaluminum compound. However, when neither the magnesium compound nor the titanium compound contains a halogen atom, the above-mentioned halogenating agent is used.

Among the methods for preparing the titanium catalyst component (A) described in the above (1) to (5), a method of using a liquid titanium halide in the preparation of the catalyst, or a method of using a halogenated carbonized material after or after using a titanium compound. A method using hydrogen is preferred.

As the electron donor used in the above preparation, diester or diester-forming compound, alcohol,
Phenol, aldehyde, ketone, ether, carboxylic acid, carboxylic anhydride, carbonate, monoester,
Examples include amines.

Among the diesters, a dicarboxylic acid ester having two carboxyl groups bonded to one carbon atom or a dicarboxylic acid ester having carboxyl groups bonded to two adjacent carbon atoms is preferably used.

Specific examples of the dicarboxylic acid used for the production of such a dicarboxylic acid ester include malonic acid, substituted malonic acid, succinic acid, substituted succinic acid, maleic acid, substituted maleic acid, fumaric acid, substituted fumaric acid, and fatty acids. 1 that forms a ring
Alicyclic dicarboxylic acid in which two carboxyl groups are bonded to two carbon atoms, an alicyclic dicarboxylic acid in which a carboxyl group is bonded to two adjacent carbon atoms forming an alicyclic ring,
Examples thereof include dicarboxylic acid esters such as an aromatic dicarboxylic acid having a carboxyl group at the ortho position and a heterocyclic dicarboxylic acid having a carboxyl group at two adjacent carbon atoms forming a heterocyclic ring.

More specific examples of the above dicarboxylic acids include malonic acid; substituted malonic acids such as methylmalonic acid, ethylmalonic acid, isopropylmalonic acid, allylmalonic acid, phenylmalonic acid; succinic acid; methylsuccinic acid, dimethyl Substituted succinic acids such as succinic acid, ethylsuccinic acid, methylethylsuccinic acid and itaconic acid; maleic acid; substituted maleic acids such as citraconic acid and dimethylmaleic acid;
Cyclopentane-1,1-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, cyclohexane-1,2-dicarboxylic acid, cyclohexene-1,6-dicarboxylic acid, cyclohexene-3,4-dicarboxylic acid, cyclohexene-4 Alicyclic dicarboxylic acids such as 1,5-dicarboxylic acid, nadic acid, methylnadic acid, 1-allylcyclohexane-3,4-dicarboxylic acid; phthalic acid, naphthalene-1,2-dicarboxylic acid, and naphthalene-2,3- Aromatic dicarboxylic acids such as dicarboxylic acids; furan-3,4-dicarboxylic acid, 4,5-dihydrofuran-2,3-dicarboxylic acid, benzopyran-3,4-dicarboxylic acid, pyrrole-2,3-dicarboxylic acid, Pyridine-
2,3-dicarboxylic acid, thiophene-3,4-dicarboxylic acid,
Examples include heterocyclic dicarboxylic acids such as indole-2,3-dicarboxylic acid and indole-2,3-dicarboxylic acid.

When two or more alcohols are used in producing the dicarboxylic acid ester, at least one of the alcohol components is preferably an alcohol having 2 or more carbon atoms, particularly preferably an alcohol having 3 or more carbon atoms. Preferably, the alcohol is an alcohol having 2 or more carbon atoms, particularly 3 or more carbon atoms.

Examples of the dicarboxylic acid ester produced using such an alcohol include, for example, diethyl ester, diisopropyl ester, di-n-propyl ester, di-n-butyl ester, diisobutyl ester, di-tert-butyl ester, di-tert-butyl ester of the above dicarboxylic acid. Examples thereof include isoamyl ester, di-n-hexyl ester, di-2-ethylhexyl ester, di-n-octyl ester, diisodecyl ester, and ethyl n-butyl ester.

Examples of the electron donor other than the diester that can be used for the preparation of the titanium catalyst component (A) include alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, acid amides, and acid anhydrides. And oxygen-containing electron donors such as alkoxysilane and nitrogen-containing electron donors such as ammonia, amine, nitrile and isocyanate.

More specifically, such electron donors include methanol, ethanol, propanol, pentanol,
Alcohols having 1 to 18 carbon atoms such as hexanol, octanol, dodecanol, octadecyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol, and isopropylbenzyl alcohol; phenol, cresol, xylenol, ethylphenol,
C6 to C20 phenols which may have a lower alkyl group such as propylphenol, nonylphenol, cumylphenol and naphthol; C3 to C15 ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone and benzophenone Acetaldehyde, propionaldehyde, octylaldehyde,
Aldehydes having 2 to 15 carbon atoms, such as benzaldehyde, tolualdehyde, and naphthaldehyde; methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, and ethyl valerate , Methyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, ethyl crotonate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, Benzyl benzoate, methyl toluate,
Ethyl toluate, amyl toluate, ethyl ethyl benzoate, methyl anisate, ethyl anisate, ethyl ethoxy benzoate, γ-butyrolactone, δ-valerolactone, coumarin, phthalide, ethylene carbonate, etc.
Organic acid esters having a carbon number of 2 to 15; acid halides having 2 to 15 carbon atoms such as acetyl chloride, benzoyl chloride, toluic acid chloride, and anisic acid chloride; methyl ether, ethyl ether, isopropyl ether, butyl ether, isoamyl ether, tetrahydrofuran, and anisole Ethers having 2 to 20 carbon atoms such as amide, diphenyl ether; acid amides such as acetic acid amide, benzoic acid amide, toluic acid amide; methylamine, ethylamine, diethylamine, tributylamine, piperidine, tribenzylamine, aniline, pyridine, picoline , Tetramethylmethylenediamine, tetramethylethylenediamine and other amines; acetonitrile, benzonitrile, tolunitrile and other nitriles; trimethyl phosphite, triethyl phosphite, etc. Organophosphorus compounds having P-O-O bonds; ethyl silicate, alkoxysilane such as diphenyldimethoxysilane and the like.
Two or more of these electron donors can be used in combination.

Among such electron donors, organic acid or inorganic acid esters, alkoxy (aryloxy) silane compounds, ethers, ketones, tertiary amines, acid halides, acid anhydrides and other electron donors having no active hydrogen are known. Preferably
Organic acid esters and alkoxy (aryloxy) silane compounds are particularly preferred, and esters composed of aromatic monocarboxylic acids and alcohols having 1 to 8 carbon atoms, malonic acid, substituted malonic acid, substituted succinic acid, maleic acid, and substituted maleic acid. Esters comprising dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid and phthalic acid and alcohols having 2 or more carbon atoms are particularly preferred. Of course, it is not necessary to use these electron donors from the beginning as raw materials when preparing a titanium catalyst. Other compounds that can be converted to these electron donors may be used as raw materials, and may be changed to these electron donors in the catalyst preparation process.

After the completion of the reaction, the titanium catalyst component (A) obtained by the above-mentioned various methods is purified by sufficiently washing it with a liquid inert hydrocarbon. Examples of such an inert liquid hydrocarbon for cleaning include n-pentane, isopentane, n-hexane, isohexane, n-heptane, and n-pentane.
Aliphatic hydrocarbons such as octane, isooctane, n-decane, n-dodecane, kerosene, and liquid paraffin; aliphatic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, and methylcyclohexane; benzene, toluene, xylene, and cymene And aromatic hydrocarbons such as chlorobenzene and dichloroethane, and mixtures thereof.

The magnesium compound used for preparing the highly stereoregular titanium catalyst component (A) is a magnesium compound having a reducing ability or a magnesium compound having no reducing ability.
Examples of the magnesium compound having a reducing ability include a magnesium compound having a magnesium-carbon bond or a magnesium-hydrogen bond. Specifically, dimethyl magnesium, diethyl magnesium, dipropyl magnesium, dibutyl magnesium, diamil Magnesium, dihexyl magnesium, didecyl magnesium, ethyl magnesium chloride,
Propyl magnesium chloride, butyl magnesium chloride,
Hexyl magnesium chloride, amyl magnesium chloride,
Butylethoxymagnesium, ethylbutylmagnesium, butylmagnesium halide and the like can be mentioned. These magnesium compounds can be used in the form of a complex compound with, for example, organoaluminum, and may be liquid or solid.

Specific examples of the magnesium compound having no reducing ability include magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide, and magnesium fluoride; methoxy magnesium chloride, ethoxy magnesium chloride, isopropoxy magnesium chloride, butoxy chloride. Magnesium, octoxymagnesium chloride, alkoxymagnesium halide; phenoxymagnesium chloride, methylphenoxymagnesium chloride, etc. aryloxymagnesium halide; ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, n-octoxymagnesium, 2-ethylhexoxymagnesium, etc. Alkoxy magnesium; aryloxymers such as phenoxy magnesium and dimethyl phenoxy magnesium Neshiumu; magnesium laurate, such as carboxylic acid salts of magnesium such as magnesium stearate and the like. The magnesium compound having no reducing ability may be a compound derived from the magnesium compound having the reducing ability described above or a compound derived at the time of preparing the catalyst component. Also,
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, a magnesium compound having no reducing ability is preferable, and a halogen-containing magnesium compound, particularly preferably magnesium chloride, alkoxymagnesium chloride, or aryloxymagnesium chloride is preferably used.

In the present invention, the titanium compound used for preparing the titanium catalyst component (A) includes, for example, Ti (OR) _g X _4-g
(R is a hydrocarbon group, X is a halogen, 0 ≦ g ≦ 4), and a tetravalent titanium compound represented by the following formula: More specifically, titanium tetrahalides such as TiCl ₄ , TiBr ₄ , and TiI ₄ ; Ti (OCH ₃ ) Cl ₃ , Ti (OC ₂ H ₅ ) Cl ₃ , Ti (On-C
_{4 H 9) Cl 3, Ti} (OC 2 H 5) Br 3, Ti (OisoC 4 H 9) trihalide, alkoxy titanium such as _{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 Br 2
Dihalogenated dialkoxy titanium, such as; Ti (OCH _{3) 3} C
_{l, Ti (OC 2 H 5} ) 3 Cl, Ti (On-C 4 H 9) 3 Cl, Ti (OC 2 H 5) 3
Monohalogenated trialkoxy titanium such as Br; Ti (OCH
₃ ) Tetraalkoxy titanium such as ₄ , Ti (OC ₂ H ₅ ) ₄ , and Ti (On-C ₄ H ₉ ) ₄ .

Among these, a halogen-containing titanium compound, particularly a titanium tetrahalide, is preferable, and titanium tetrachloride is more preferably used. These titanium compounds may be used alone or in the form of a mixture. Alternatively, it may be used after being diluted with a hydrocarbon or a halogenated hydrocarbon.

The amount of each component used when preparing the titanium catalyst component (A) as described above differs depending on the preparation method and cannot be specified unconditionally.
The electron donor to be supported is used in an amount of about 0.1 to 10 mol, and the titanium compound is used in an amount of about 0.05 to 1000 mol per mol.

As the organoaluminum compound catalyst component (B), a compound having at least one Al-carbon bond in the molecule can be used. For example, (i) a general formula R ¹ _m Al (OR ² ) _n H _p X _q ( In the formula, R ¹ and R ² may be the same or different and each may be a hydrocarbon group containing usually 1 to 15, preferably 1 to 4, carbon atoms, X is a halogen, m is 0 <m ≦ 3, and n is 0 ≦ n <
3, p is 0 ≦ p <3, q is a number of 0 ≦ q <3, moreover organic aluminum compound represented by m + n + p + q = a 3), (ii) the general formula M ¹ AlR ¹ ₄ (wherein , M ¹ is Li, Na, K, and R ¹ is the same as described above).

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

General formula R ¹ _m Al (OR ² ) _3-m (wherein R ¹ and R ² are the same as above. M is preferably 1.5
≦ m ≦ 3), a general formula R ¹ _m AlX _3-m (wherein R ¹ is the same as above; X is a halogen, m is preferably 0 <m <3); and a general formula R ¹ _m AlH _3-m (wherein R ¹ is the same as above; m is preferably 2 ≦ m <3); and a general formula R ¹ _m Al (OR ² ) _n X _q (wherein R ¹ and R ² is the same as above, X is halogen, 0 <
m <3, 0 ≦ n <3, 0 ≦ q <3, and m + n + q = 3).

As the aluminum compound belonging to (i), more specifically, trialkylaluminums such as triethylaluminum and tributylaluminum; trialkenylaluminums such as triisoprenylaluminum; dialkylaluminum yloxide such as diethylaluminum ethoxide and dibutylaluminum butoxide Sid; alkyl aluminum sesquialkoxides such as ethyl aluminum sesquiethoxide and butyl aluminum sesquibutoxide, and partially alkoxylated alkyl aluminum having an average composition represented by R ¹ _2.5 Al (OR ² ) _0.5 ; Dialkylaluminum halides such as diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide;
Alkyl aluminum sesquihalides such as ethyl aluminum sesquichloride, butyl aluminum sesquichloride and ethyl aluminum sesquibromide; partially halogenated alkyl aluminum such as alkyl aluminum dihalides such as ethyl aluminum dichloride, propyl aluminum dichloride and butyl aluminum dibromide Diethyl aluminum hydride;
Dialkylaluminum hydrides, such as dibutylaluminum hydride; other partially hydrogenated alkylaluminums, such as alkylaluminum dihydrides, such as ethylaluminum dihydride and propylaluminum dihydride; ethylaluminum ethoxycyclolide, butylaluminum butoxycyclolide, ethylaluminum ethoxy Mention may be made of partially alkoxylated and halogenated alkylaluminums such as bromides. Compounds similar to (i) include:
An organic aluminum compound in which two or more aluminum atoms are bonded via an oxygen atom or a nitrogen atom can be given.
Examples of such a compound include (C ₂ H ₅ ) ₂ AlOAl
(C ₂ H ₅ ) ₂ , (C ₄ H ₉ ) ₂ AlOAl (C ₄ H ₉ ) ₂ , And the like.

As the compound belonging to the above (ii), LiAl (C
_{2 H 5) 4, LiAl (} C 7 H 15) 4 and the like.

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

Examples of the electron donor (C) include amines, amides, ethers, ketones, nitriles, phosphines, stippins, arsines, phosphoramides, esters,
Thioethers, thioesters, acid anhydrides, acid halides, aldehydes, alcoholates, alkoxy (aryloxy) silanes, organic acids and amides of metals belonging to Groups I to IV of the Periodic Table; Salts and the like can be mentioned. Salts can be obtained, for example, by reacting an organic acid with an organometallic compound used as the catalyst component (B).

Specific examples thereof can be selected from the compounds exemplified above as the electron donor contained in the titanium catalyst component (A). Among these, organic acid esters, alkoxy (aryloxy) silane compounds,
It is preferable to use ether, ketone, acid anhydride, amine and the like. In particular, when the electron donor in the titanium catalyst component (A) is a monocarboxylic acid ester, the electron donor component (C) is preferably an alkyl ester of an aromatic carboxylic acid.

When the electron donor in the titanium catalyst component (A) is an ester obtained by reacting a dicarboxylic acid with an alcohol having 2 or more carbon atoms, the general formula RnSi (OR ¹ ) _4-n (wherein , R and R ¹ are preferably an alkoxy (aryloxy) silane compound represented by a hydrocarbon group 0 ≦ n ≦ 4) or an amine having a large steric hindrance as the electron donor component (C).

Specific examples of the alkoxy (aryloxy) silane compound include trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane,
Ethyltrimethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane,
Phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane,
Examples include ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriaryloxysilane, vinyltris (β-methoxyethoxysilane), vinyltriacetoxysilane, and dimethyltetraethoxydisiloxane.

Among these, trimethylmethoxysilane,
Preferred are trimethylethoxysilane, trimethyl-n-propoxysilane, triethylmethoxysilane, tri-n-propylmethoxysilane, tri-iso-propylmethoxysilane, triphenylmethoxysilane and the like.

Examples of the amine having a large steric hindrance include 2,2,6,6-tetramethylpiperidine, 2,2,5,5-tetramethylpyrrolidine, derivatives thereof, and tetramethylmethylenediamine.

In the present invention, a branched α-olefin is used as a raw material. As such a branched α-olefin, a branched α-olefin having from 5 to 10 carbon atoms and having a branch at the 3rd or higher position is usually used.

Such branched α-olefins include 3-methyl-1-pentene, 4-methyl-1-pentene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 4,4-dimethyl -1-hexene, 3-methyl-1-hexene, 4,
4-dimethyl-1-pentene, 3-ethyl-pentene,
Vinyl cyclohexane and the like can be mentioned. Among these branched α-olefins, 4-methyl-1-pentene is preferably used.

In the present invention, the above-mentioned branched α-olefin and linear α-olefin can be copolymerized.

As such a straight-chain α-olefin, usually, a straight-chain α-olefin having 2 to 20 carbon atoms is used.

Such linear α-olefins include ethylene,
Examples thereof include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, and 1-dodecene. Among these linear α-olefins, particularly, linear α-olefins having 6 to 14 carbon atoms such as 1-hexene, 1-octene, 1-decene, 1-dodecene, and 1-tetradecene are preferably used. Can be

In the present invention, when performing a copolymerization reaction of a branched α-olefin and a linear α-olefin, both are usually derived from the branched α-olefin in the respective branched α-olefin polymers. It is used in such an amount that the repeating unit is 8 to 100 mol% and the repeating unit derived from the linear α-olefin is 0 to 20 mol%.

The proportions of the branched α-olefin and the linear α-olefin used depend on the types of both α-olefins, the catalyst, the reaction conditions and the like, but are easily determined by simple experiments.

In the present invention, the branched α-olefin can be polymerized without using an inert medium, but usually, an inert medium is used when polymerizing the branched α-olefin. Examples of such an inert medium include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane and kerosene; alicyclic hydrocarbons such as cyclopentane and cyclohexane; benzene, toluene, xylene and the like. Aromatic hydrocarbons; halogenated hydrocarbons such as dichloroethane, methylene chloride, and chlorobenzene; and mixtures thereof. Of these, aliphatic hydrocarbons are particularly preferably used.

In the present invention, in the presence of the catalyst as described above,
The polymerization of the branched α-olefin is carried out, but a preliminary polymerization as described below may be carried out before such polymerization (main polymerization).

By performing such a prepolymerization, in the main polymerization, the catalyst exhibits a large polymerization activity, a powder polymer having a high bulk density can be obtained, and a polymer yield per unit catalyst amount is increased. The stereoregularity of the resulting branched α-olefin polymer tends to be improved.

In the prepolymerization, as described above, a catalyst formed from the titanium catalyst component (A), at least a part of the organoaluminum compound catalyst component (B), and at least a part of the electron donor component (C) is used. In a suitable hydrocarbon medium, the branched α-olefins are reacted in an amount of about 1 to 1000 g per mmol of titanium in the titanium catalyst component (A).

Although the branched α-olefin used for the prepolymerization is not particularly limited, usually, an α-olefin having 5 to 10 carbon atoms and having a branch at the 3 or more position is used for the prepolymerization, Specifically, the branched α-olefin used in the main polymerization described later can be exemplified.

The prepolymerization is preferably carried out under relatively mild conditions and under conditions in which the produced prepolymer is not dissolved in the polymerization medium. For this purpose, an inert hydrocarbon such as an aliphatic hydrocarbon such as butane, pentane, hexane, heptane, octane, decane, dodecane or kerosene, or an alicyclic hydrocarbon such as cyclopentane or cyclohexane may be used as a polymerization medium. preferable.

In the prepolymerization, for example, the titanium catalyst component (A) is converted to titanium atoms in an amount of about 0.1 per hydrocarbon medium.
5 to 100 mmol, preferably about 1 to 10 mmol, of the organoaluminum compound catalyst component (B) in an amount such that Al / Ti (atomic ratio) is about 1 to 100, preferably about 2 to 80; The electron donor (C) is used in an amount of about 0.01 to 2 mol, preferably about 0.01 mol, per mol of the organoaluminum compound catalyst component (B).
It is preferable to use each in such an amount that it becomes 1 mol.

The polymerization amount of the branched α-olefin to be prepolymerized is
Usually, it is about 1 to 1000 g, preferably about 3 to 500 g per 1 mmol of titanium in the titanium catalyst component (A). In order to carry out the above amount of prepolymerization, a predetermined amount of the above-mentioned branched α-olefin may usually be used. The concentration of the branched α-olefin in the prepolymerization is desirably about 1 mol or less, preferably about 0.5 mol or less per hydrocarbon medium.

The prepolymerization temperature is preferably a temperature at which the resulting prepolymer does not dissolve in the hydrocarbon medium, and varies depending on the type of the hydrocarbon medium. For example, about -20 to +70
C., preferably about 0-50.degree.

In the present invention, in the presence of a catalyst as described above,
In the polymerization vessel, polymerization of the branched α-olefin (main polymerization) is performed in a liquid phase.

At the time of the main polymerization, each catalyst component is used in an amount of about 0.001 to 0.1 mmol, preferably about 0.001 to 0.05 mmol, in terms of titanium atom, per polymerization deposition volume.
It is preferable to prepare Ti (atomic ratio) to be about 1 to 1000, preferably about 2 to 1000. In addition, as this catalyst, it is preferable to use the catalyst used at the time of performing the preliminary polymerization as described above as it is.

However, in the present invention, the organoaluminum compound catalyst component (B) can be newly added and used, if necessary. Furthermore, usually, it is preferable to use by adding an electron donor (C). The organoaluminum compound catalyst component (B) and the electron donor (C) may form a complex compound.

When the main polymerization of the branched α-olefin is performed after the prepolymerization as described above, the organoaluminum compound catalyst component (B) and / or the electron donor component ( C) may be additionally used.
In this case, the organoaluminum compound catalyst component (B)
Is usually used in an amount of about 1 to 1000 mol, preferably about 10 to 1000 mol, per mol of titanium, and the electron donor component (C) is usually added in an amount of about 0.005 to 1 mol per mol of the organoaluminum catalyst component (B).
It is preferable to additionally use the compound in an amount of ２2 mol, preferably 0.01-1 mol.

In the polymerization system, hydrogen, a halogenated hydrocarbon, or the like may be additionally used for the purpose of adjusting the molecular weight or the molecular weight distribution.

In the present invention, the polymerization temperature is a temperature within a range in which suspension polymerization is possible, and is preferably about 0 ° C. or more, preferably about 30 to 70 ° C. The polymerization pressure is, for example, from atmospheric pressure to about 200 kg / cm ² , preferably from atmospheric pressure to about 100 kg / c.
It is desirably within the range of m ² . And the polymerization time is
It is preferable to set the amount of the produced polymer to be about 5000 g or more, preferably about 10,000 g or more per 1 mmol of titanium in the titanium catalyst component.

The main polymerization may be performed in one stage or may be performed in multiple stages.

In the present invention, as shown in FIG. 1, a polymer solution containing a branched α-olefin-based polymer polymerized in the polymerization vessel A as described above is supplied to the cooling vessel C through the control valve B. And cooled to precipitate a branched α-olefin-based polymer dissolved in the polymer solution.

The cooling temperature of the polymer solution is usually 5 ° C. or lower, preferably 20 ° C. or lower, more preferably 40 ° C. or lower than the polymerization temperature.

When such a polymer solution is cooled at a temperature which is usually at least 5 ° C. lower than the polymerization temperature, the branched α-
The olefin polymer precipitates. Therefore, the produced polymer can be efficiently recovered in the separation step.

In order to precipitate the branched α-olefin polymer in the cooler, either a continuous method or a batch method can be employed.

In the present invention, the polymer dispersion precipitated in the cooling step is then introduced into the separator E via the control valve D,
The polymer produced in the polymerization step is separated from unreacted branched α-olefin.

The branched α-olefin polymer thus separated is recovered, and the separated unreacted branched α-olefin is supplied into the polymerization vessel A via the mother liquor drum F and the mother liquor circulation pump G. And reuse.

As the separator E, a centrifuge, a liquid cyclone, or the like is used.

The intrinsic viscosity [η] of the thus-obtained branched α-olefin polymer is usually in the range of 0.5 to 20 dl / g, preferably 1 to 10 dl / g.

Effects of the Invention In the present invention, a polymer obtained by polymerizing a branched α-olefin in a liquid phase in the presence of a catalyst in a polymerization vessel while producing a branched α-olefin-based polymer, The polymer solution containing the polymer is introduced into the cooler and cooled to precipitate a polymer dissolved in the polymer solution, and then the polymer solution containing the polymer is introduced into the separator. The resulting polymer is separated from unreacted branched α-olefin, and the polymer is recovered and the separated branched α-olefin is supplied to the polymerization vessel and reused. The α-olefin-based polymer can be efficiently recovered at a high recovery rate.

Further, in the mother liquor after the recovery of the branched α-olefin polymer, the amount of the remaining dissolved polymer is small, and the mother liquor drum is separated from devices such as a separator, a mother liquor drum, a mother liquor circulation pump or the separator. In the mother liquor discharge line leading to the mother liquor and the mother liquor circulation line from the mother liquor drum to the polymerization vessel via the mother liquor circulating pump, the polymer hardly precipitates and adheres, so that the line is less likely to be clogged. Operation is possible.

[Examples] Next, the method of the present invention will be specifically described with reference to Examples.

Examples 1 to 4 <Preparation of titanium catalyst component (a)> Anhydrous magnesium chloride 4.76 kg (50 mol), decane 25
After heating 23.4 (150 mol) of 2-ethylhexyl alcohol at 130 ° C. for 2 hours to form a homogeneous solution, 1.11 kg (7.5 mol) of phthalic anhydride was added to this solution.
The mixture was further stirred for 1 hour at ℃ to dissolve the phthalic anhydride in the homogeneous solution. After the thus obtained homogeneous solution was cooled to room temperature, the whole amount was dropped into titanium tetrachloride 200 (1800 mol) kept at -20 ° C over 1 hour. After completion of the charging, the temperature of the mixed solution was raised to 110 ° C. over 4 hours, and when the temperature reached 110 ° C., 2.68 (12.5 mol) of isodibutyl phthalate was added.
It was kept under stirring at the same temperature for a time. After the completion of the reaction for 2 hours, a solid portion was collected, resuspended in the solid portion with 200 titanium tetrachloride (TiCl ₄ ), and then heated again at 110 ° C. for 2 hours. After the completion of the reaction, the solid portion was collected again by heating, and sufficiently washed with decane and hexane at 110 ° C. until no free titanium compound was detected in the washing solution. The titanium catalyst component (a) synthesized by the above production method was stored as a hexane suspension of the titanium catalyst component (a), except that a part of the titanium catalyst component (a) was dried for the purpose of examining the catalyst composition. The composition of the titanium catalyst component (a) obtained by drying in this way is 3.1% by weight of titanium, 56.0% by weight of chlorine,
17.0% by weight of magnesium and diisobutyl phthalate
It was 20.9% by weight.

<Preliminary polymerization> 25 n-decane, 250 mmol of triethylaluminum, 50 mmol of trimethylmethoxysilane and 250 mmol of a titanium catalyst component (a) in terms of titanium atoms were charged into 50 reactors with a stirrer. While maintaining the temperature at 20 ° C, 7.5 kg of 4-methyl-1-pentene was added to the reactor over 1 hour, and the reaction was further performed at 20 ° C for 2 hours. Further, 500 g of 3-methyl-1-pentene was added all at once to the reactor, and reacted at 20 ° C. for 2 hours. The resulting reaction was passed through a glass filter and resuspended in 25 n-hexane. Prepolymerization amount is 300 g per 1 mmol of titanium
Met.

<Polymerization> The polymerization apparatus used is shown in FIG.

In FIG. 1, polymerization vessel A (diameter 500 mm, volume 200)
And the above-mentioned reactant as a hexane suspension (preliminary polymerization catalyst)
Is continuously supplied at a rate shown in Table 1 in terms of titanium atoms, and triethylaluminum, trimethylmethoxysilane, 4-methyl-1-pentene, and 1-decene are also supplied at the rates shown in Table 1, respectively. While continuously supplying hydrogen to the polymerization vessel so as to have a gaseous partial pressure shown in Table 1,
The suspension polymerization reaction was performed continuously.

At the time of this polymerization reaction, the temperature was set to 50 ° C., and the pressure in the polymerization vessel was set to 3 kg / cm ² G by pressurizing with nitrogen.

The volume of the reaction part was controlled by adjusting the amount of the suspension withdrawn so that the average residence time of the reactants in the polymerization vessel was 4 hours.

<Cooling> The suspension continuously discharged from the polymerization vessel A was continuously introduced into the cooler C (diameter 500 mm, volume 200) via the line 1 and cooled.

Upon cooling, the coolant was continuously flowed through the jacket.
During cooling, the temperature in the cooler was kept at the value shown in Table 1.

The pressure in the cooler is increased by 1kg /
cm ² G.

The volume of the cooling part was controlled so that the suspension withdrawal amount was adjusted so that the average residence time of the suspension in the cooler was 1 hour.

The amount of the polymer precipitated by cooling was determined by measuring the amount of the suspension discharged from the polymer and the amount of the polymer dissolved in the liquid phase in the suspension discharged from the cooler.

<Separation> The suspension continuously discharged from the cooler C was continuously introduced into the centrifugal separator E via the line 2, and separated into a polymer and a mother liquor.

The separated mother liquor was once stored in the mother liquor drum F via the mother liquor discharge line 3 and then circulated from the mother liquor drum to the polymerization vessel A via the mother liquor circulation pump G and the mother liquor circulation line 4.

After operating the above polymerization apparatus for 24 hours, the conditions of the centrifugal separator E, the mother liquor discharge line 3 and the mother liquor circulation line 4 were examined.

 The results are shown in Table 1.

Comparative Example 1 <Preparation of titanium catalyst component (a)> The same procedure as in Examples 1 to 4 was performed.

<Preliminary polymerization> It carried out similarly to Examples 1-4.

<Polymerization> In the following steps, a polymerization apparatus as shown in FIG. 2 was used.

 Performed in the same manner as in Example 1.

<Separation> The suspension continuously discharged from the polymerization vessel A was supplied to the line 1
After that, the mixture was continuously introduced into a centrifugal separator E, and separated into a polymer and a mother liquor. The separated mother liquor was once stored in the mother liquor drum F via the mother liquor discharge line 3, and then circulated from the mother liquor drum to the polymerization vessel A via the mother liquor circulation pump G and the mother liquor circulation line 4.

10 hours after the operation of the polymerization apparatus as shown in FIG. 2 was started, blockage occurred in the line 3 and the suction line of the pump G, and the operation of the polymerization apparatus became impossible. Line 3,
Inspection of mother liquor drum F, pump G and line 4,
The polymer deposited on each inner wall and adhered was detected.

[Brief description of the drawings]

FIG. 1 is a schematic view of a polymerization apparatus used in an embodiment of the present invention, and FIG. 2 is a schematic view of a conventional polymerization apparatus. A: Polymerizer, B, D: Control valve C: Cooler, E: Separator F: Mother liquor drum, G: Mother liquor circulation pump

Claims (1)

(57) [Claims] In a polymerization vessel, a branched α-olefin is polymerized in a liquid phase in the presence of a catalyst, and a polymer solution containing the obtained polymer is introduced into a cooler and cooled. By, the polymer dissolved in the polymer solution is precipitated, then,
A polymer solution containing this polymer is introduced into a separator to separate a polymer formed and an unreacted branched α-olefin,
A method for producing a branched α-olefin polymer, comprising recovering the polymer and supplying the separated branched α-olefin to the polymerization vessel for reuse.