JP2022170339A - Method for preserving transition metal complex solution, and olefin polymerization method using the transition metal complex solution - Google Patents

Abstract

To provide a transition metal complex compound solution having olefin polymerization activity for a long time, and provide a method for efficiently producing an olefinic polymer using the solution.SOLUTION: The present invention discloses a method for preserving a transition metal complex solution that contains a hafnium halide complex compound (A), an organometallic compound (B), and a hydrocarbon compound (C) with the metal element molar ratio between the component (A) and the component (B) [(A)/(B)] of 1/1 to 1/500; and an olefin polymer production method to perform olefin polymerization using the transition metal complex solution.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a method for storing a transition metal compound solution having long-term olefin polymerization activity and a method for polymerizing an olefin using the transition metal complex solution.

Ethylene/α-olefin copolymers have hitherto been used in various applications. For example, it is known that a crosslinked product using an ethylene/α-olefin copolymer is crosslinked after being melt-molded and used for electrical cable coating, wall paper, and the like.

Cross-linked foams using ethylene/α-olefin copolymers have high mechanical strength, are lightweight and flexible, and are therefore used in building exterior materials, interior materials, automotive parts such as door glass runs, packaging materials, and daily necessities. In addition to being used for such purposes, attempts have been made to use it for footwear or footwear parts, for example, soles (mainly midsoles) of sports shoes and the like. In particular, footwear or footwear parts are required to be lightweight and have excellent durability. A footwear component has been proposed.

So-called metallocene compounds are known to be useful as components of catalysts for producing olefin polymers, particularly ethylene/α-olefin copolymers. It has been reported that metallocene compounds exhibit high activity in olefin polymerization and are suitable for obtaining high-performance olefin polymers without removing catalyst residues (for example, Patent Document 2, etc.).

On the other hand, it is disclosed that a dialkyl-type metallocene compound is unstable in a solution state, and a stable solution can be obtained by coexisting with an organoaluminum compound (Patent Document 3).

JP 2008-308619 A JP 2018-165308 A JP-A-7-2918

Transition metal complex compounds, typically metallocene compounds, are often obtained as solid compounds. Transition metal complex compounds have concerns about their stability due to their high activity, but they are relatively stable as solids at room temperature. When used for olefin polymerization, the transition metal complex compound is often used as a slurry or solution in an inert medium such as a hydrocarbon compound in order to facilitate quantitative use. In particular, when used for solution polymerization, which is suitable for producing amorphous polymers such as elastomers, it is preferable to use it as a transition metal complex compound solution.

According to the studies of the present inventors, among transition metal complex compounds, hafnium complexes are particularly unstable, and not only hafnium dialkyl type complex compounds but also hafnium halide complex compounds may not be suitable for long-term storage. I have learned something. That is, it has been found that a solution of a hafnium halide complex compound stored for a long period of time gradually loses its olefin polymerization activity, possibly due to decomposition or deterioration.

On the other hand, olefin polymers are known as inexpensive polymers, and in order to produce them more efficiently, attempts are being made to scale up the process and produce them at high concentrations. For this reason, from the viewpoint of stabilizing production and reducing man-hours, it is preferable that the transition metal complex compound solution be prepared in as large a quantity as possible and stored for a long period of time.

The problem to be solved by the present invention is to obtain a transition metal complex compound solution having long-term olefin polymerization activity. Another object of the present invention is to provide a method for efficiently producing an olefin polymer using the solution.

As a result of studies by the present inventors, it was found that the performance of the transition metal complex compound does not deteriorate for a long period of time by using a solution containing the transition metal complex compound and the organometallic compound. That is, the present invention is specified as follows.
[1]
A hafnium halide complex compound (A), an organometallic compound (B), and a hydrocarbon compound (C) are included, and the metal element molar ratio between the component (A) and the component (B) [(A)/(B )] is in the range of 1/1 to 1/500.
[2]
The method for storing a transition metal compound solution according to item [1], wherein the hafnium halide type complex compound (A) is a metallocene compound (A').
[3]
The method for storing a transition metal compound solution according to item [1] or item [2], wherein the organometallic compound (B) is an organoaluminum compound.
[4]
A method for producing an olefin polymer, comprising polymerizing an olefin using the transition metal compound solution according to any one of items [1] to [3].

Even if the transition metal compound solution of the present invention is stored for a long period of time, for example, 30 to 1000 hours, the olefin polymerization activity does not decrease. In addition, the number of adjustments of the transition metal complex compound solution can be reduced during the continuous polymerization operation, and the production efficiency of the olefin polymer can be enhanced.

1 is a structural example of a production apparatus for carrying out the olefin polymerization method of the present invention.

The hafnium halide type complex compound (A), the organometallic compound (B), the hydrocarbon compound (C), which constitute the transition metal compound solution of the present invention, and the method for producing an olefin polymer using the transition metal compound solution will be explained. do.

[Hafnium Halide Type Complex Compound (A)]
As the hafnium halide type complex compound (A), which is one of the components constituting the transition metal compound solution of the present invention, any known hafnium halide type complex compound can be used. Suitable examples include the metallocene compound (A'). More suitable metallocene compounds include, for example, compounds represented by the following general formula [A1] [hereinafter sometimes referred to as "transition metal complex (1)". ].

<R ¹ to R ⁸ >
In formula [A1], R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently hydrogen atom, hydrocarbon group, halogen-containing group, oxygen-containing group, nitrogen selected from containing groups, boron-containing groups, sulfur-containing groups, phosphorus-containing groups, silicon-containing groups, germanium-containing groups, and tin-containing groups, which may be the same or different, and adjacent groups are bonded together to form a ring; may be formed.

Hydrocarbon groups include, for example, alkyl groups, cycloalkyl groups, alkenyl groups, aryl groups and arylalkyl groups. Examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-pentyl group, neopentyl group and n-hexyl group. , n-octyl, nonyl, dodecyl and eicosyl groups. Cycloalkyl groups include, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl and adamantyl groups. Alkenyl groups include, for example, vinyl groups, propenyl groups and cyclohexenyl groups. Aryl groups include, for example, phenyl group, tolyl group, dimethylphenyl group, trimethylphenyl group, ethylphenyl group, propylphenyl group, biphenyl group, α- or β-naphthyl group, methylnaphthyl group, anthracenyl group, phenanthryl group, benzyl A phenyl group, a pyrenyl group, an acenaphthyl group, a phenalenyl group, an acanthrilenyl group, a tetrahydronaphthyl group, an indanyl group and a biphenylyl group. Arylalkyl groups include, for example, benzyl, phenylethyl and phenylpropyl groups.

<Y>
In formula [A1], Y is a divalent group that binds two ligands, specifically a divalent group, a hydrocarbon group having 1 to 20 carbon atoms, and a halogen-containing group, a silicon-containing group, a germanium-containing group and a tin-containing group, preferably a C 1-20 divalent hydrocarbon group or a divalent silicon-containing group.

The divalent hydrocarbon group includes an alkylene group, a substituted alkylene group and an alkylidene group, specific examples of which are
Alkylene groups such as methylene, ethylene, propylene and butylene;
Isopropylidene, diethylmethylene, dipropylmethylene, diisopropylmethylene, dibutylmethylene, methylethylmethylene, methylbutylmethylene, methyl-t-butylmethylene, dihexylmethylene, dicyclohexylmethylene, methylcyclohexylmethylene, methylphenylmethylene, diphenylmethylene, ditolyl substituted alkylene groups such as methylene, methylnaphthylmethylene, dinaphthylmethylene, 1-methylethylene, 1,2-dimethylethylene and 1-ethyl-2-methylethylene; and cyclopropylidene, cyclobutylidene, cyclopentylidene, cyclohexyl Cycloalkylidene groups such as sylidene, cycloheptylidene, bicyclo[3.3.1]nonylidene, norbornylidene, adamantylidene, tetrahydronaphtylidene and dihydroindanidene and alkylidene groups such as ethylidene, propylidene and butylidene .

As a divalent silicon-containing group,
silylene; and methylsilylene, dimethylsilylene, diisopropylsilylene, dibutylsilylene, methylbutylsilylene, methyl-t-butylsilylene, dicyclohexylsilylene, methylcyclohexylsilylene, methylphenylsilylene, diphenylsilylene, ditolylsilylene, methylnaphthylsilylene, dinaphthyl Alkylsilylene groups such as silylene, cyclodimethylsilylene, cyclotrimethylenesilylene, cyclotetramethylenesilylene, cyclopentamethylenesilylene, cyclohexamethylenesilylene and cycloheptamethylenesilylene, and particularly preferably dimethylsilylene and dibutylsilylene. and dialkylsilylene groups such as

〈M〉
In Formula [A1], M is hafnium (Hf).

<X>
In the formula [A1], X is a halogen atom, and examples of the halogen atom include fluorine, chlorine, bromine and iodine, with chlorine being particularly preferred.

Specific examples of the transition metal complex (1) include structures corresponding to the compounds listed in [0077] of JP-A-2013-224408.
Further, as a more suitable metallocene compound, a compound represented by the following general formula [A2] may be mentioned [hereinafter sometimes referred to as "transition metal complex (2)". ].

<R ¹ to R ⁶ and R ¹¹ to R ¹⁶ >
In formula [A2], R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom, selected from hydrocarbon groups, halogen-containing groups, oxygen-containing groups, nitrogen-containing groups, boron-containing groups, sulfur-containing groups, phosphorus-containing groups, silicon-containing groups, germanium-containing groups and tin-containing groups, whether identical or different; Alternatively, two adjacent groups may be linked together to form a ring.

Examples of the hydrocarbon group include the hydrocarbon groups exemplified as R ¹ to R ⁸ in formula [A1] above.
R ¹ to R ⁶ and R ¹¹ to R ¹⁶ are each independently preferably a hydrogen atom or a hydrocarbon group, more preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.

<Y>
In formula [A2], Y is a divalent group that bonds two ligands, specifically a divalent group, a hydrocarbon group having 1 to 20 carbon atoms, and a halogen-containing group, a silicon-containing group, a germanium-containing group and a tin-containing group, preferably a C 1-20 divalent hydrocarbon group or a divalent silicon-containing group.
These groups include the divalent groups exemplified as Y in the above formula [A1].

〈M〉
In formula [A2], M is hafnium (Hf).

<X>
In formula [A2], X is a halogen atom, and examples of halogen atoms include fluorine, chlorine, bromine and iodine, with chlorine being particularly preferred.

Specific examples of the transition metal complex (2) include structures corresponding to the compounds listed in [0071] of JP-A-2013-224408.
Further, as a more suitable metallocene compound, a compound represented by the following general formula [A3] may be mentioned [hereinafter sometimes referred to as "transition metal complex (3)". ].

< ^R1 to ^R14 >
In formula [A3], R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are each independently is a hydrogen atom, a hydrocarbon group, a heteroatom-containing hydrocarbon group or a silicon-containing group, and any two of the substituents R ¹ to R ⁴ are bonded to each other to form a ring any two of the substituents R ⁵ to R ¹² may be bonded together to form a ring, and R ¹³ and R ¹⁴ may be bonded together to form a ring may be

Hydrocarbon groups for R ¹ to R ¹⁴ include, for example, one or more of linear hydrocarbon groups, branched hydrocarbon groups, saturated cyclic hydrocarbon groups, unsaturated cyclic hydrocarbon groups, and saturated hydrocarbon groups. is substituted with a cyclic unsaturated hydrocarbon group. The number of carbon atoms in the hydrocarbon group is usually 1-20, preferably 1-15, more preferably 1-10.

Linear hydrocarbon groups include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl straight-chain alkyl groups such as groups, n-decanyl groups; and straight-chain alkenyl groups such as allyl groups.

Branched hydrocarbon groups include, for example, isopropyl group, tert-butyl group, tert-amyl group, 3-methylpentyl group, 1,1-diethylpropyl group, 1,1-dimethylbutyl group, 1-methyl-1 -propylbutyl group, 1,1-propylbutyl group, 1,1-dimethyl-2-methylpropyl group, 1-methyl-1-isopropyl-2-methylpropyl group and other branched alkyl groups.

Examples of the cyclic saturated hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and methylcyclohexyl group; polycyclic groups such as norbornyl group, adamantyl group and methyladamantyl group. be done.

Examples of cyclic unsaturated hydrocarbon groups include phenyl, tolyl, naphthyl, biphenyl, phenanthryl, anthracenyl and other aryl groups; cyclohexenyl and other cycloalkenyl groups; 5-bicyclo[2.2. 1] polycyclic unsaturated alicyclic groups such as hept-2-enyl group.

Examples of the group obtained by substituting one or more hydrogen atoms of a saturated hydrocarbon group with a cyclic unsaturated hydrocarbon group include a benzyl group, a cumyl group, a 1,1-diphenylethyl group, a triphenylmethyl group, and the like. A group obtained by substituting one or more hydrogen atoms of the alkyl group of with an aryl group.

Examples of heteroatom-containing hydrocarbon groups for R ¹ to R ¹⁴ include alkoxy groups such as methoxy and ethoxy, aryloxy groups such as phenoxy, and oxygen-containing hydrocarbon groups such as furyl; N-methylamino; amino groups such as N,N-dimethylamino group and N-phenylamino group; nitrogen atom-containing hydrocarbon groups such as pyryl group; and sulfur atom-containing hydrocarbon groups such as thienyl group. The carbon number of the heteroatom-containing hydrocarbon group is generally 1-20, preferably 2-18, more preferably 2-15. However, heteroatom-containing hydrocarbon groups exclude silicon-containing groups.

Examples of silicon-containing groups for R ¹ to R ¹⁴ include trimethylsilyl, triethylsilyl, dimethylphenylsilyl, diphenylmethylsilyl, and triphenylsilyl groups of the formula —SiR ₃ (wherein a plurality of R independently an alkyl group having 1 to 15 carbon atoms or a phenyl group).

Any two substituents among R ¹ to R ¹⁴ , for example, two adjacent substituents (e.g., R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , R ⁷ and R ⁸ , R ⁹ and R ¹⁰ , R ¹⁰ and R ¹¹ , R ¹¹ and R ¹² , R ¹³ and R ¹⁴ ) are bonded together to form a ring; good too. The ring formation may occur at two or more sites in the molecule.

In the present specification, the ring (additional ring) formed by bonding two substituents to each other includes, for example, an alicyclic ring, an aromatic ring, and a heterocyclic ring. Specific examples include a cyclohexane ring; a benzene ring; a hydrogenated benzene ring; a cyclopentene ring; benzene ring. Moreover, such a ring structure may further have a substituent such as an alkyl group on the ring.

R ⁵ , R ⁸ , R ⁹ and R ¹² are preferably hydrogen atoms.
R ⁶ , R ⁷ , R ¹⁰ and R ¹¹ are preferably a hydrogen atom, a hydrocarbon group, an oxygen atom-containing hydrocarbon group or a nitrogen atom-containing hydrocarbon group, more preferably a hydrocarbon group. R ⁶ and R ⁷ may be bonded together to form a ring, and R ¹⁰ and R ¹¹ may be bonded together to form a ring. Examples of the structure of the fluorenyl group moiety as described above include those represented by the following formulae.

R ¹³ and R ¹⁴ are preferably a hydrocarbon group, a heteroatom-containing hydrocarbon group or a silicon-containing group, more preferably an aryl group or a substituted aryl group (an aryl group having a heteroatom-containing hydrocarbon group or a silicon-containing group ).

<Y>
In formula [A3], Y is a carbon atom, a silicon atom, a germanium atom or a tin atom, preferably a carbon atom.

<M, Q, j>
In formula [A3], M is hafnium (Hf).
Q is a halogen atom, and examples of halogen atoms include fluorine, chlorine, bromine and iodine, with chlorine being particularly preferred.
j is an integer of 1 to 4, preferably 2; When j is an integer of 2 or more, Q may be selected in the same or different combinations.

Specific examples of the transition metal complex (3) include compounds listed on pages 29 to 43 of WO 2004/87775 and compounds listed on pages 9 to 37 of WO 2006/25540. , compounds listed in [0117] of International Publication No. 2015/122414, and structures according to compounds listed in [0143] of International Publication No. 2015/122415 can be exemplified.

[Organometallic compound (B)]
The organometallic compound (B), which is one of the components constituting the transition metal compound solution of the present invention, is an organometallic compound having a known reducing ability.

Specific examples of the organometallic compound according to the present invention are described below.
Examples of organometallic compounds according to the present invention include organometallic compounds containing groups 1 and 2 of the periodic table.

Other preferred examples include organometallic compounds containing Group 13 metals of the periodic table. Among them, the following organoaluminum compounds described in JP-A-2010-248526 are preferable.

[Organoaluminum compound]
Examples of the organoaluminum compound according to the present invention include an organoaluminum compound represented by the following general formula (6), a complex alkylated product of a Group 1 metal and aluminum represented by the following general formula (7), or an organoaluminum compound. Oxy compounds and the like can be mentioned.
R am Al (OR ^{b )} _n H _p X _{q (} 6)
(Wherein, R ^a and R ^b may be the same or different and represent a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms, X represents a halogen atom, m is 0 <m≤3, n is 0≤n<3, p is 0≤p<3, q is a number satisfying 0≤q<3, and m+n+p+q=3.)
^{M2AlRa4 (} ₇ )
(In the formula, M ² represents Li, Na or K, and R ^a represents a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms.)

Examples of the organoaluminum compound represented by the general formula (6) include compounds represented by the following general formulas (8), (9), (10), and (11).
R ^a _m Al (OR ^b ) _3-m (8)
(Wherein, R ^a and R ^b may be the same or different and represent a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms, and m is preferably 1.5 ≤ m ≤ is the number of 3.)
R ^a _m AlX _3-m (9)
(In the formula, R ^a represents a hydrocarbon group having 1 to 15, preferably 1 to 4, carbon atoms, X represents a halogen atom, and m preferably satisfies 0<m<3.)
R ^a _m AlH _3-m (10)
(In the formula, R ^a represents a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms, and m preferably satisfies 2≦m<3.)
R am Al (OR ^{b )} _n X _{q (} 11)
(Wherein, R ^a and R ^b may be the same or different and represent a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms, X represents a halogen atom, m is 0 <m≤3, n is 0≤n<3, q is a number satisfying 0≤q<3, and m+n+q=3.)

More specifically, the aluminum compound represented by the general formula (8), (9), (10) or (11) includes trimethylaluminum, triethylaluminum, tri-n-butylaluminum, tripropylaluminum, tri- tri-n-alkylaluminum such as pentylaluminum, trihexylaluminum, trioctylaluminum and tridecylaluminum; Tri-branched such as 3-methylbutylaluminum, tri-2-methylpentylaluminum, tri-3-methylpentylaluminum, tri-4-methylpentylaluminum, tri-2-methylhexylaluminum, tri-3-methylhexylaluminum, tri-2-ethylhexylaluminum Chain alkylaluminum; tricycloalkylaluminum such as tricyclohexylaluminum and tricyclooctylaluminum; triarylaluminum such as triphenylaluminum and tritolylaluminum; dialkylaluminum hydride such as diisopropylaluminum hydride and diisobutylaluminum hydride; alkenyl aluminum such as isoprenyl aluminum represented by _C4H9 ) _{xAly ( C5H10} ) _z (wherein _x , _y and z are positive numbers and z≧2x), etc. Alkyl aluminum alkoxides such as isobutyl aluminum methoxide, isobutyl aluminum ethoxide and isobutyl aluminum isopropoxide; Dialkyl aluminum alkoxides such as dimethyl aluminum methoxide, diethyl aluminum ethoxide and dibutyl aluminum butoxide; Ethyl aluminum sesquiethoxide and butyl aluminum sesqui alkyl aluminum sesquialkoxides such as butoxide; partially alkoxylated aluminum alkyls having an average composition represented by the general formula R ^a _2.5 Al(OR ^b ) _0.5 ; -t-butyl-4-methylphenoxide), ethylaluminum bis(2,6-di-t-butyl-4-methylphenoxide), diisobutylaluminum (2,6-di-t-butyl alkylaluminum aryloxides such as ethyl-4-methylphenoxide), isobutylaluminum bis(2,6-di-t-butyl-4-methylphenoxide); dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide , diisobutylaluminum chloride, etc.; alkylaluminum sesquihalides, such as ethylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide; etc.; dialkylaluminum hydrides such as diethylaluminum hydride, dibutylaluminum hydride; other partially hydrogenated alkylaluminum dihydrides such as ethylaluminum dihydride, propylaluminum dihydride, etc. Aluminum; partially alkoxylated and halogenated alkylaluminums such as ethylaluminum ethoxychloride, butylaluminum butoxychloride, ethylaluminum ethoxybromide, and the like.

A compound similar to the compound represented by the above general formula (6) can also be used, for example, an organoaluminum compound in which two or more aluminum compounds are bonded via a nitrogen atom. Specific examples of such compounds include (C ₂ H ₅ ) ₂ AlN(C ₂ H ₅ )Al(C ₂ H ₅ ) ₂ and the like.

Examples of the compound represented by the general formula (7) include LiAl(C ₂ H ₅ ) ₄ and LiAl(C ₇ H ₁₅ ) ₄ .

Compounds that form the above organoaluminum compounds in the polymerization system, such as a combination of an aluminum halide and an alkyllithium, or a combination of an aluminum halide and an alkylmagnesium, can also be used.
Of these, organoaluminum compounds are preferred.

The organoaluminum compound represented by the general formula (6) or the complex alkylated product of the Group 1 metal and aluminum represented by the general formula (7) is used singly or in combination of two or more. .

Among these, trialkylaluminum and tricycloalkylaluminum are preferable, and trimethylaluminum, triethylaluminum and triisobutylaluminum are particularly preferable. These are used individually by 1 type or in combination of 2 or more types.

It may also be an organometallic compound used as a co-catalyst component of an olefin polymerization catalyst, which will be described later.

[Hydrocarbon compound (C)]
The hydrocarbon compound (C), which is one of the components constituting the transition metal compound solution of the present invention, dissolves the hafnium halide complex compound (A) and the organometallic compound (B) to form a solution. is a compound.

In a preferred embodiment, the hydrocarbon compound (C) according to the present invention is liquid at normal temperature and normal pressure. Of course, as long as it is a hydrocarbon compound that becomes liquid under high pressure conditions, it may be a gaseous compound at normal temperature and normal pressure.

Specific examples of the hydrocarbon compound (C) according to the present invention include aromatic hydrocarbons such as benzene, toluene, xylene, cumene, and cymene, pentane, hexane, heptane, octane, decane, dodecane, hexadecane, octadecane, and the like. , alicyclic hydrocarbons such as cyclopentane, cyclohexane, cyclooctane and methylcyclopentane, and petroleum fractions such as gasoline, kerosene and light oil.

The hydrocarbon compound (C) according to the present invention may be a halide such as a chloride or bromide of the aromatic hydrocarbon, aliphatic hydrocarbon or alicyclic hydrocarbon.
Examples of hydrocarbon compounds that are gaseous at normal temperature and normal pressure but become liquid under high pressure conditions include methane, ethane, propanes, butanes, and pentanes.

Among these hydrocarbon compounds, aromatic hydrocarbon compounds or aliphatic hydrocarbon compounds are preferred. In addition, propanes, butanes, and pentanes are preferred as preferred gaseous hydrocarbon compounds at normal temperature and normal pressure from the viewpoint of being easily liquefied.

The hydrocarbon compound (C) may be used in combination with heteroatom-containing hydrocarbon compounds having no active hydrogen, such as ethers such as ethyl ether and tetrahydrofuran. Such a compound is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less based on 100% by mass of the hydrocarbon compound (C). can be used at a ratio of

《Transition metal compound solution》
The transition metal compound solution of the present invention contains the hafnium halide complex compound (A), the organometallic compound (B), and the hydrocarbon compound (C), and the component (A) and the component (B) The metal element molar ratio [(A)/(B)] of is in the range of 1/1 to 1/500.

In the transition metal compound solution of the present invention, the upper limit of the molar ratio [(A)/(B)] between the component (A) and the component (B) is preferably 1/2, more preferably 1/5, more preferably 1/10. On the other hand, the lower limit is preferably 1/400, more preferably 1/200, and even more preferably 1/100.

The concentrations of the hafnium halide complex compound (A) and the organometallic compound (B) are desirably higher from the viewpoint of preservation. On the other hand, since the hafnium halide type complex compound (A) is highly active and needs to be used after being diluted when it is used for olefin polymerization, which will be described later, the concentration is preferably relatively low from that point of view.

From these viewpoints, the concentration of the hafnium halide type complex compound (A) in the solution is preferably 0.0001 to 10 mol/liter as the concentration of the contained metal element, and a more preferable lower limit is 0.0002 mol. /liter, more preferably 0.0005 mol/liter. On the other hand, a more preferable lower limit is 8 mol/liter, more preferably 5 mol/liter, and particularly preferably 2 mol/liter.

The concentration of the organometallic compound (B) in the solution is preferably 0.01 to 10 mol/liter as the concentration of the metal element contained, and a more preferable lower limit is 0.02 mol/liter, More preferably, it is 0.05 mol/liter. On the other hand, a more preferable lower limit is 8 mol/liter, more preferably 5 mol/liter, and particularly preferably 2 mol/liter.

The temperature at which the transition metal compound solution of the present invention is stored is preferably in the range of -20°C to 50°C. A more preferred lower limit is -10°C, more preferably 0°C. On the other hand, the upper limit is more preferably 40°C, more preferably 35°C. In general, a lower storage temperature tends to be suitable for long-term storage.

In the transition metal compound solution of the present invention, the metal element molar ratio [(A)/(B)] between the component (A) and the component (B) is in the range of 1/1 to 1/500. , the function (activity) as an olefin polymerization catalyst, which will be described later, does not deteriorate even when stored for a relatively long time, specifically 30 to 1000 hours. According to studies by the present inventors, a transition metal compound solution having a ratio of component (A) to component (B) higher than the above range loses its olefin polymerization activity after 1 to 2 days of storage. Within the above range, there is no significant change in polymerization performance even after storage for 10 days or more.
The factors that cause the improvement in storage performance as described above have not been clarified. The inventors presume as follows.

The hafnium halide complex compound (A) and the organometallic compound (B) probably have a weak interaction. This aspect blocks the action of the disturbance substance on the transition metal complex compound, suppresses the molecular motion of the transition metal complex compound itself that becomes more mobile when it becomes a solution, and also suppresses alteration due to such molecular motion. I believe that there are. In particular, hafnium is a large atom compared to zirconium and titanium. If the ligand or X in the above structural formula effectively blocked the influence of the disturbance substance on the central transition metal, in the case of hafnium, X is a polar group such as halogen. I think that it may not be able to completely block, and it may be easily affected by disturbance substances. It is believed that the organometallic compound (B) compensates for such weak points by the action as described above.

Organometallic compounds (B) are generally known to alter other substances due to their reducing ability and the like. For example, it is known that a solid titanium catalyst component produced using titanium halide or the like exhibits polymerization performance in the presence of an organometallic compound, but is reduced over time to reduce polymerization performance. .

The hafnium halide type complex compound (A) according to the present invention is probably due to the effect of the ligand, but the reduction reaction as described above does not proceed and only the protective action from disturbance is preferentially expressed. I am thinking of the possibility of doing so.

<<Method for producing olefin polymer>>
The method for producing an olefin polymer of the present invention is characterized in that the olefin is polymerized in the presence of the transition metal compound solution.

As the method for producing the olefin polymer of the present invention, as long as the transition metal compound solution is used as a catalyst component for the olefin polymerization reaction, the same methods as conventionally known methods for producing an olefin polymer can be appropriately employed.
Each condition and the like will be described below.

In the method for producing an olefin polymer of the present invention, any of batch polymerization, continuous polymerization, and semi-continuous polymerization can be employed as the polymerization mode of the olefin polymer. The hafnium halide type complex compound (A), the organometallic compound (B), and the hydrocarbon compound (C) are included when a polymerization process is used, and the metal element moles of the component (A) and the component (B) A transition metal compound solution in which the ratio [(A)/(B)] is in the range of 1/1 to 1/500 is considered to function effectively.

A reaction apparatus for polymerization includes a reaction vessel made of SUS or the like and a rotatable stirring shaft having stirring blades. Examples of the stirring blades include inclined paddle blades, turbine blades, anchor blades, helical ribbon blades, large plate blades, and the like.

The size of the reactor or reactor used in the production method of the present invention is preferably in the range of 1 liter to 1000 cubic meters. A more preferred lower limit is 5 liters, more preferably 10 liters. On the other hand, the upper limit is more preferably 800 cubic meters, more preferably 700 cubic meters. The excessive supply of ethylene to the olefin polymerization catalyst, which is considered to be the cause of cloudiness, tends to occur more easily when the size of the reactor or reactor is large. If so, the oversupply of olefins such as ethylene to the olefin polymerization catalyst, which is considered to be the cause of cloudiness, will be less likely to occur.

[Polymerization temperature]
In the production method of the present invention, the preferred polymerization temperature for producing the olefin polymer is -20 to 200°C. A more preferred lower limit is 0°C, more preferably 20°C. On the other hand, the upper limit is more preferably 190°C, more preferably 180°C. If the temperature is within such a range, the desired olefin polymer can be obtained with high polymerization activity.

[Polymerization pressure]
In the production method of the present invention, the polymerization pressure (P) in producing the olefin polymer is preferably 0.1 to 10 MPa, more preferably 0.2 MPa, and still more preferably 0.3 MPa. On the other hand, a more preferable upper limit is 8 MPa, and more preferably 6 MPa.
If the polymerization pressure is within such a range, it tends to be possible to produce the desired olefin polymer with high polymerization activity.

[About raw material supply]
In the production method of the present invention, the supply rate of ethylene, olefins such as α-olefins, and hydrogen to the reactor depends on the amount of the hafnium halide type complex compound (A) contained in the transition metal compound solution and the heat removal of the reactor. It is determined by taking into consideration the ability and the like. A case of copolymerizing ethylene and α-olefin will be described below as an example.

The feed amount ratio of ethylene and α-olefin is preferably 0.001-1,000, more preferably 0.01-100, still more preferably 0.1-10. All of these ratios are molar ratios.

The molecular weight of the olefin polymer to be produced can be controlled by the polymerization temperature, etc., which will be described later.
The supply amount ratio of ethylene and hydrogen is preferably 0.001 to 500,000, more preferably 0.01 to 100,000, still more preferably 0.1 to 10,000. All of these ratios are molar ratios. Of course, when producing a low-molecular-weight olefin polymer for lubricating oil applications, the above ratio tends to be relatively small. A specific preferred range is l0.001 to 100,000, more preferably 0.01 to 10,000, still more preferably 0.1 to 1,000. All of these ratios are molar ratios.

Preferred residence times are from 1 minute to 10 hours, more preferably from 2 minutes to 8 hours, even more preferably from 5 minutes to 5 hours. When the production method of the ethylene-based copolymer is continuous polymerization, the residence time can be regarded as the polymerization time.

In the production method of the present invention, polymerization is carried out in the presence of the hafnium halide complex compound (A). In this case, the hafnium halide type complex compound (A) contained in the transition metal compound solution has a transition metal atom concentration in the polymerization reaction system of usually 10 ⁻⁸ to 10 ⁻² gram atoms/liter, preferably It is used in amounts ranging from 10 ^-7 to 10 ^-3 gram atoms/liter.

The amount of the organometallic compound (B) contained in the transition metal compound solution is usually 0.1 to 100 mol, preferably 0.1 mol, in terms of metal atom, per 1 mol of the transition metal atom in the transition metal compound. It is used in an amount such that 5 to 50 mol.
The olefin polymerization catalyst described above is supplied separately from ethylene in the reactor shown in FIG. 1, which will be described later.

[One Mode of Reactor]
The production of the olefin polymer described above is carried out, for example, in a reaction apparatus having a liquid phase (liquid phase) and a gas phase (gas phase) as shown in FIG.
In the reactor, as shown in FIG. 1, gases such as ethylene and hydrogen are supplied into the reactor at the ratio required in (I) above.

When an ethylene copolymer is produced in the reactor shown in FIG. (EM2) is preferably in the range of 1 to 50, for example. By controlling the composition of both gases within the above range, there is a tendency to suppress the spread of the composition distribution, such as the occurrence of cloudiness.

In the reactor shown in Figure 1, the production of ethylene-based copolymers is carried out in a continuous polymerization process. In the continuous polymerization process, unreacted gas is circulated and reused (hereinafter, this reused unreacted gas is also referred to as circulating gas). Specifically, as shown in FIG. 1, it is preferable to add an appropriate amount of raw material ethylene, hydrogen, or other gas to the above circulating gas whose pressure has been adjusted by a compressor, and then supply it to the liquid phase of the reaction system. . By adopting such a method, it is possible to easily control the composition of the supplied gas within a preferable range and to efficiently prevent cloudiness.

The method for producing the olefin polymer of the present invention is often carried out by continuous solution polymerization using a transition metal compound solution as shown in FIG. In this case, it is important to select conditions that allow long-term continuous operation. Considering these things, in addition to the above conditions, it is preferable to carry out the reaction system with a polymer concentration in the range of 1 to 90% by mass, more preferably 5 to 85% by mass, and still more preferably 10 to 80% by mass. be. If the polymer concentration is within the above range, adverse effects such as fouling are unlikely to occur, which is advantageous for stable operation over a long period of time.

As described above, the method for producing an olefin polymer of the present invention contains the hafnium halide complex compound (A), the organometallic compound (B), and the hydrocarbon compound (C), and the component (A) and the ( It is characterized by using a transition metal compound solution having a metal element molar ratio [(A) / (B)] with component B in the range of 1/1 to 1/500. Hafnium halide type complex compound (A ) and the organometallic compound (B), it is preferable to combine the following specific compounds.

Examples of the above compounds include compounds that react with the hafnium halide complex compound (A) to form the following ion pairs and organoaluminum oxy compounds. (In the present invention, boron may also be regarded as a metallic element.) Such components are sometimes referred to as co-catalyst components of so-called olefin polymerization catalysts.

[Compound that forms an ion pair by reacting with the hafnium halide complex compound (A)]
Compounds that form an ion pair by reacting with the hafnium halide type complex compound (A) include JP-A-1-501950, JP-A-1-502036, JP-A-3-179005, JP-A-3. -179006, JP-A-3-207703, JP-A-3-207704, USP-5321106, Lewis acids, ionic compounds, borane compounds and carborane compounds.

Specifically, Lewis acids include compounds represented by BR ₃ (R is a phenyl group or fluorine optionally having a substituent such as fluorine, a methyl group, a trifluoromethyl group, etc.). such as trifluoroboron, triphenylboron, tris(4-fluorophenyl)boron, tris(3,5-difluorophenyl)boron, tris(4-fluoromethylphenyl)boron, tris(pentafluorophenyl)boron, tris (p-tolyl) boron, tris(o-tolyl) boron, tris(3,5-dimethylphenyl) boron, trimethyl boron, triisobutyl boron and the like.
Examples of ionic compounds include compounds represented by the following general formula (1).

In the formula, R ^e+ includes H ⁺ , carbenium cation, oxonium cation, ammonium cation, phosphonium cation, cycloheptyltrienyl cation, ferrocenium cation having a transition metal, and the like. R ^f to R ⁱ may be the same or different and are organic groups, preferably aryl groups or substituted aryl groups.

Specific examples of the carbenium cation include trisubstituted carbenium cations such as triphenylcarbenium cation, tris(methylphenyl)carbenium cation, and tris(dimethylphenyl)carbenium cation.

Specific examples of the ammonium cation include trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tri(n-propyl)ammonium cation, triisopropylammonium cation, tri(n-butyl)ammonium cation, and triisobutylammonium cation. , N,N-dimethylanilinium cation, N,N-diethylanilinium cation, N,N-dialkylanilinium cation such as N,N-2,4,6-pentamethylanilinium cation, diisopropylammonium cation, dicyclohexyl Examples include dialkylammonium cations such as ammonium cations.

Specific examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tris(methylphenyl)phosphonium cation, and tris(dimethylphenyl)phosphonium cation.

Among the above, R ^e+ is preferably a carbenium cation, an ammonium cation, or the like, and particularly preferably a triphenylcarbenium cation, an N,N-dimethylanilinium cation, or an N,N-diethylanilinium cation.

Specific carbenium salts include triphenylcarbenium tetraphenylborate, triphenylcarbeniumtetrakis(pentafluorophenyl)borate, triphenylcarbeniumtetrakis(3,5-ditrifluoromethylphenyl)borate, tris(4-methyl phenyl)carbeniumtetrakis(pentafluorophenyl)borate, tris(3,5-dimethylphenyl)carbeniumtetrakis(pentafluorophenyl)borate and the like.

Examples of ammonium salts include trialkyl-substituted ammonium salts, N,N-dialkylanilinium salts, and dialkylammonium salts.
Specific trialkyl-substituted ammonium salts include triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tri(n-butyl)ammonium tetraphenylborate, trimethylammonium tetrakis(p-tolyl)borate, trimethylammonium tetrakis(o -tolyl)borate, tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate, triethylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(2,4- dimethylphenyl)borate, tri(n-butyl)ammonium tetrakis(3,5-dimethylphenyl)borate, tri(n-butyl)ammonium tetrakis(4-trifluoromethylphenyl)borate, tri(n-butyl)ammonium tetrakis( 3,5-ditrifluoromethylphenyl)borate, tri(n-butyl)ammonium tetrakis(o-tolyl)borate, dioctadecylmethylammonium tetraphenylborate, dioctadecylmethylammonium tetrakis(p-tolyl)borate, dioctadecylmethylammonium tetrakis(o-tolyl)borate, dioctadecylmethylammonium tetrakis(pentafluorophenyl)borate, dioctadecylmethylammonium tetrakis(2,4-dimethylphenyl)borate, dioctadecylmethylammonium tetrakis(3,5-dimethylphenyl)borate, dioctadecylmethylammonium tetrakis(4-trifluoromethylphenyl)borate, dioctadecylmethylammonium tetrakis(3,5-ditrifluoromethylphenyl)borate, dioctadecylmethylammonium and the like.

Specific examples of N,N-dialkylanilinium salts include N,N-dimethylanilinium tetraphenylborate, N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis(3 ,5-ditrifluoromethylphenyl)borate, N,N-diethylanilinium tetraphenylborate, N,N-diethylaniliniumtetrakis(pentafluorophenyl)borate, N,N-diethylaniliniumtetrakis(3,5-ditri fluoromethylphenyl)borate, N,N-2,4,6-pentamethylanilinium tetraphenylborate, N,N-2,4,6-pentamethylanilinium tetrakis(pentafluorophenyl)borate and the like.

Specific examples of dialkylammonium salts include di(1-propyl)ammonium tetrakis(pentafluorophenyl)borate, dicyclohexylammonium tetraphenylborate and the like.

Furthermore, ferrocenium tetrakis(pentafluorophenyl)borate, triphenylcarbenium pentaphenylcyclopentadienyl complex, N,N-diethylanilinium pentaphenylcyclopentadienyl complex, or the following formula (2) or (3) or a borate compound containing active hydrogen represented by the following formula (4), or a borate compound containing a silyl group represented by the following formula (5).

（式中、Ｅｔはエチル基を示す。）

(In the formula, Et represents an ethyl group.)

Borate compounds containing active hydrogen:
[B-Qn(Gq(T-H)r)z] ^{−A +} (4)
Here, B represents boron. G represents a multi-bonded hydrocarbon radical, and preferred multi-bonded hydrocarbons are alkylene, arylene, ethylene and alkarylene radicals containing 1 to 20 carbon atoms. Preferred examples of G include phenylene, bisphenylene, naphthalene, methylene, ethylene, propylene, 1,4-butadiene, p-phenylenemethylene. The multi-bonded radical G has bonds r+1, ie one bond is attached to the borate anion and the other bond r of G is attached to the (TH) group. A ⁺ is a cation.

T in the general formula above represents O, S, NR ^j , or PR ^j , and R ^j represents a hydrocarbanyl radical, trihydrocarbanylsilyl radical, trihydrocarbanylgermanium radical, or hydride. q is an integer of 1 or more, preferably 1; TH groups include —OH, —SH, —NRH, or PR ^j H, where R ^j is a hydrocarbyl radical of 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, or hydrogen. . Preferred R ^j are alkyl, cycloalkyl, allyl, arylalkyl or alkylaryl having 1 to 18 carbon atoms. -OH, -SH, ^-NRjH or ^PRjH are, for example, -C(O)-OH, -C(S)-SH-C(O) ^-NRjH and C(O)-PR ^jH is also acceptable. The most preferred group with active hydrogen is the --OH group. Q is hydride, dihydrocarbylamide, preferably dialkylamide, halide, hydrocarbyloxide, alkoxide, allyloxide, hydrocarbyl, substituted hydrocarbyl radical and the like. where n+z is 4.

Examples of [B-Qn(Gq(T-H)r)z] in the above general formula (4) include triphenyl(hydroxyphenyl)borate, diphenyl-di(hydroxyphenyl)borate, triphenyl(2,4-dihydroxyphenyl) ) borate, tri(p-tolyl)(hydroxyphenyl)borate, tris(pentafluorophenyl)(hydroxyphenyl)borate, tris(2,4-dimethylphenyl)(hydroxyphenyl)borate, tris(3,5-dimethylphenyl) ) (hydroxyphenyl)borate, tris[3,5-di(trifluoromethyl)phenyl](hydroxyphenyl)borate, tris(pentafluorophenyl)(2-hydroxyethyl)borate, tris(pentafluorophenyl)(4- hydroxybutyl)borate, tris(pentafluorophenyl)(4-hydroxycyclohexyl)borate, tris(pentafluorophenyl)[4-(4-hydroxyphenyl)phenyl]borate, tris(pentafluorophenyl)(6-hydroxy-2 -naphthyl)borate and the like, most preferably tris(pentafluorophenyl)(4-hydroxyphenyl)borate. Furthermore, those borate compounds in which the --OH group is substituted with --NHR ^j (wherein R ^j represents methyl, ethyl or t-butyl) are also preferred.

Examples of A ⁺ as a counter cation of the borate compound include carbonium cation, tropyllium cation, ammonium cation, oxonium cation, sulfonium cation, and phosphonium cation. In addition, cations of metals and organometallic cations, which themselves are easily reduced, can also be used. Specific examples of these cations include triphenylcarbonium ion, diphenylcarbonium ion, cycloheptatrinium, indenium, triethylammonium, tripropylammonium, tributylammonium, dimethylammonium, dipropylammonium, dicyclohexylammonium, trioctylammonium, N,N-dimethylammonium, diethylammonium, 2,4,6-pentamethylammonium, N,N-dimethylphenylammonium, di-(i-propyl)ammonium, dicyclohexylammonium, triphenylphosphonium, triphosphonium, tridimethylphenyl Phosphonium, tri(methylphenyl)phosphonium, triphenylphosphonium ion, triphenyloxonium ion, triethyloxonium ion, pyrinium, silver ion, gold ion, platinum ion, copper ion, palladium ion, mercury ion, ferrocenium ion, etc. is mentioned. Among them, ammonium ion is particularly preferred.

Borate compounds containing silyl groups:
[B-Qn( ^Gq ( ^{SiRkRlRm )} r)z] ^{-A +} (5)
Here, B represents boron. G represents a multi-bonded hydrocarbon radical, and preferred multi-bonded hydrocarbon radicals are alkylene, arylene, ethylene and alkarylene radicals containing 1 to 20 carbon atoms, and preferred examples of G are phenylene and bisphenylene. , naphthalene, methylene, ethylene, propylene, 1,4-butadiene, p-phenylene methylene. The multi-bonded radical G has bonds r+1, ie one bond is bonded to the borate anion and the other bond r of G is bonded to the (SiR ^k R ^l R ^m ) group. A ⁺ is a cation.

R ^k , R ^l , and R ^m in the general formula above represent a hydrocarbanyl radical, a trihydrocarbanylsilyl radical, a trihydrocarbanylgermanium radical, a hydrogen radical, an alkoxy radical, a hydroxyl radical, or a halogen compound radical. R ^k , R ^l and R ^m are independent of each other and may be the same or different groups. Q is hydride, dihydrocarbylamide, preferably dialkylamide, halide, hydrocarbyloxide, alkoxide, allyloxide, hydrocarbyl, substituted hydrocarbyl radical and the like, more preferably pentafluorobenzyl radical. where n+z is 4.

[B-Qn(Gq(SiR ^k R ^l R ^m )r)z] ^- in the general formula (5) includes, for example, triphenyl(4-dimethylchlorosilylphenyl) borate, diphenyl-di(4-dimethylchlorosilyl) phenyl)borate, triphenyl(4-dimethylmethoxysilylphenyl)borate, tri(p-tolyl)(4-triethoxysilylphenyl)borate, tris(pentafluorophenyl)(4-dimethylchlorosilylphenyl)borate, tris( pentafluorophenyl)(4-dimethylmethoxysilylphenyl)borate, tris(pentafluorophenyl)(4-trimethoxysilylphenyl)borate, tris(pentafluorophenyl)(6-dimethylchlorosilyl-2naphthyl)borate and the like. be done. The counter cation A ⁺ of the borate compound is the same as A ⁺ in the above formula (4).

Specific examples of borane compounds include decaborane (14), bis[tri(n-butyl)ammonium]nonaborate, bis[tri(n-butyl)ammonium]decaborate, bis[tri(n-butyl)ammonium]undecaborate. , anion salts such as bis[tri(n-butyl)ammonium] dodecaborate, bis[tri(n-butyl)ammonium]decachlorodecaborate, bis[tri(n-butyl)ammonium]dodecachlorododecaborate, tri Salts of metal borane anions such as (n-butyl) ammonium bis(dodecahydride dodecaborate) cobaltate (III) and bis[tri(n-butyl)ammonium] bis(dodecahydride dodecaborate) nickelate (III) etc.

Specific examples of carborane compounds include 4-carbanonaborane (14), 1,3-dicarbanonaborane (13), 6,9-dicarbadecaborane (14), dodecahydride-1-phenyl-1,3- Dicarbanonaborane, dodecahydride-1-methyl-1,3-dicarbanonaborane, undecahydride-1,3-dimethyl-1,3-dicarbanonaborane, 7,8-dicarbaundecaborane (13 ), 2,7-dicarboundecaborane (13), undecahydride-7,8-dimethyl-7,8-dicarboundecaborane, dodecahydride-11-methyl-2,7-dicarboundecaborane, tri (n-butyl) ammonium 1-carbadecaborate, tri(n-butyl) ammonium 1-carbaundecaborate, tri(n-butyl) ammonium 1-carbadodecaborate, tri(n-butyl) ammonium 1-trimethylsilyl- 1-carbadecaborate, tri(n-butyl)ammonium bromo-1-carbadodecaborate, tri(n-butyl)ammonium 6-carbadecaborate (14), tri(n-butyl)ammonium 6-carbadecaborate ( 12), tri(n-butyl)ammonium 7-carbaundecaborate (13), tri(n-butyl)ammonium 7,8-dicarbaundecaborate (12), tri(n-butyl)ammonium 2,9- Dicarbaundecaborate (12), Tri(n-butyl)ammonium dodecahydride-8-methyl-7,9-dicarbaundecaborate, Tri(n-butyl)ammonium undecahydride-8-ethyl-7,9- Dicarbaundecaborate, tri(n-butyl)ammonium undecahydride-8-butyl-7,9-dicarbaundecaborate, tri(n-butyl)ammonium undecahydride-8-allyl-7,9-dicarbaun Decaborate, tri(n-butyl)ammonium undecahydride-9-trimethylsilyl-7,8-dicarboundecaborate, tri(n-butyl)ammonium undecahydride-4,6-dibromo-7-carbaundecaborate salts of anions such as; -dicarboundecaborate) iron acid salt (III), tri(n-butyl)ammonium bis(undecahydride-7,8-dicarboundecaborate) cobaltate (III), tri(n-butyl)ammonium bis(undecahydride-7, 8-dicarbaundecaborate)nickelate (III), tri(n-butyl)ammonium bis(undecahydride-7,8-dicarbaundecaborate)cuprate(III), tri(n-butyl)ammonium Bis(undecahydride-7,8-dicarbaundecaborate)aurate (III), tri(n-butyl)ammonium bis(nonahydride-7,8-dimethyl-7,8-dicarbaundecaborate)iron acid (III), tri(n-butyl)ammonium bis(nonahydride-7,8-dimethyl-7,8-dicarbaundecaborate) chromate (III), tri(n-butyl)ammonium bis(tri bromooctahydride-7,8-dicarbaundecaborate) cobaltate (III), tris[tri(n-butyl)ammonium]bis(undecahydride-7-carbaundecaborate) chromate (III), Bis[tri(n-butyl)ammonium]bis(undecahydride-7-carbaundecaborate)manganate (IV), bis[tri(n-butyl)ammonium]bis(undecahydride-7-carbaune decaborate) cobaltate (III), bis[tri(n-butyl)ammonium]bis(undecahydride-7-carboundecaborate)nickelate (IV) and the like, and salts of metal carborane anions. .

Two or more kinds of compounds that react with the hafnium halide complex compound (A) to form an ion pair can be used in combination.

(organoaluminumoxy compound)
The organoaluminumoxy compound may be a conventionally known aluminoxane, or a benzene-insoluble organoaluminumoxy compound as exemplified in JP-A-2-78687.

Conventionally known aluminoxanes can be produced, for example, by the following method, and are usually obtained as a solution in a hydrocarbon solvent.
(1) Compounds containing adsorbed water or salts containing water of crystallization, such as magnesium chloride hydrate, copper sulfate hydrate, aluminum sulfate hydrate, nickel sulfate hydrate, cerous chloride hydrate, etc. A method of adding an organoaluminum compound such as trialkylaluminum to the hydrocarbon medium suspension of (1) and reacting the adsorbed water or water of crystallization with the organoaluminum compound.
(2) A method in which water, ice or steam is directly acted on an organoaluminum compound such as trialkylaluminum in a medium such as benzene, toluene, ethyl ether or tetrahydrofuran.
(3) A method of reacting an organoaluminum compound such as trialkylaluminum with an organotin oxide such as dimethyltin oxide or dibutyltin oxide in a medium such as decane, benzene or toluene.

The aluminoxane may also contain small amounts of organometallic components. Alternatively, the solvent or the unreacted organoaluminum compound may be removed by distillation from the recovered aluminoxane solution, and then redissolved in the solvent or suspended in a poor solvent for the aluminoxane.

Specific examples of the organoaluminum compound used in preparing the aluminoxane include the same organoaluminum compounds as those exemplified as the organoaluminum compound represented by the general formula (8).
Among these, trialkylaluminum and tricycloalkylaluminum are preferred, and trimethylaluminum is particularly preferred.

The organoaluminum compounds as described above may be used singly or in combination of two or more. Incidentally, an aluminoxane prepared from trimethylaluminum is called methylaluminoxane or MAO, and is a particularly frequently used compound.

Solvents used for the preparation of aluminoxanes include aromatic hydrocarbons such as benzene, toluene, xylene, cumene, and cymene; aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, hexadecane, and octadecane; , cyclohexane, cyclooctane, methylcyclopentane and other alicyclic hydrocarbons, petroleum fractions such as gasoline, kerosene and light oil, or the above aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbon halides, especially chlorine and hydrocarbon solvents such as bromides and bromides. Ethers such as ethyl ether and tetrahydrofuran can also be used. Among these solvents, aromatic hydrocarbons or aliphatic hydrocarbons are particularly preferred.

In the benzene-insoluble organoaluminumoxy compound used in the present invention, the Al component dissolved in benzene at 60° C. is usually 10% or less, preferably 5% or less, particularly preferably 2% or less in terms of Al atoms. is insoluble or sparingly soluble in

As the organoaluminumoxy compound used in the present invention, an organoaluminumoxy compound containing boron represented by the following general formula (12) can also be mentioned.

（式中、Ｒ^cは炭素原子数が１～１０の炭化水素基を示す。Ｒ^dは、互いに同一でも異なっていてもよく、水素原子、ハロゲン原子又は炭素原子数が１～１０の炭化水素基を示す。）

(In the formula, R ^c represents a hydrocarbon group having 1 to 10 carbon atoms; R ^d may be the same or different; indicates the group.)

The organoaluminumoxy compound containing boron represented by the above general formula (12) is prepared by adding an alkylboronic acid represented by the following general formula (13) and an organoaluminum compound in an inert solvent under an inert gas atmosphere. at -80°C to room temperature for 1 minute to 24 hours.
^RcB (OH) ₂ (13)
(Wherein, R ^c represents the same group as above.)

Specific examples of alkylboronic acids represented by the general formula (13) include methylboronic acid, ethylboronic acid, isopropylboronic acid, n-propylboronic acid, n-butylboronic acid, isobutylboronic acid, and n-hexylboronic acid. acid, cyclohexylboronic acid, phenylboronic acid, 3,5-difluorophenylboronic acid, pentafluorophenylboronic acid, 3,5-bis(trifluoromethyl)phenylboronic acid and the like. Among these, methylboronic acid, n-butylboronic acid, isobutylboronic acid, 3,5-difluorophenylboronic acid and pentafluorophenylboronic acid are preferred. These are used individually by 1 type or in combination of 2 or more types.

Specific examples of the organoaluminum compound to be reacted with such an alkylboronic acid include the same organoaluminum compounds as those exemplified as the organoaluminum compound represented by the general formula (6) or (7). .
The organoaluminumoxy compounds used in the present invention may be used singly or in combination of two or more.

Among the organoaluminum compounds described above, an organoaluminum oxy compound can be mentioned as a suitable compound.
In addition to the above boron compounds and organoaluminumoxy compounds, the above organometallic compounds (B) can also be used. This organometallic compound (B) may be used in combination with a boron compound or an organoaluminumoxy compound as described above.

[Other components used in the reaction]
In the present invention the polymerization reaction is usually carried out in a hydrocarbon medium. Specific examples of such hydrocarbon media include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene, and alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane. Hydrogen, aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane; and petroleum fractions such as gasoline, kerosene and light oil. Furthermore, olefins used for polymerization can also be used.
In addition, it may be used in combination with known components that are considered useful for the polymerization reaction. For example, fluorine-containing compounds (alcohol compounds, etc.) can be used.

[Olefin]
The olefins used in the olefin polymerization of the present invention include ethylene, α-olefins such as propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, C3-C20 linear or A branched α-olefin can be exemplified. As the α-olefin, linear or branched α-olefins having 3 to 10 carbon atoms are preferable, and propylene, 1-butene, 1-hexene and 1-octene are more preferable. When the obtained polymer is used for applications such as lubricating oils, olefins having a small number of carbon atoms, such as ethylene and propylene, are preferred from the viewpoint of shear stability. On the other hand, olefins having a relatively large number of carbon atoms, such as 1-butene, 1-hexene, 1-octene and 1-decene, are preferred for use as modifiers for improving the impact resistance of resins. These olefins can be used singly or in combination of two or more.

In the present invention, copolymerization may be carried out using other copolymerizable olefinic monomers in addition to ethylene and α-olefin. Examples of such olefinic monomers include polyenes, vinyl aromatic compounds, vinyl alicyclic compounds, cyclic olefins, and the like.

Polyenes include 1,4-hexadiene, 1,5-hexadiene, 1,5-heptadiene, 1,6-heptadiene, 1,6-octadiene, 1,7-octadiene, 1,7-nonadiene, 1,8- nonadiene, 1,8-decadiene, 1,9-decadiene, 1,12-tetradecadiene, 1,13-tetradecadiene, 3-methyl-1,4-hexadiene, 3-methyl-1,5-hexadiene, 3-ethyl-1,4-hexadiene, 3-ethyl-1,5-hexadiene, 3,3-dimethyl-1,4-hexadiene, 3,3-dimethyl-1,5-hexadiene, dicyclopentadiene, 5- ethylidene-2-norbornene, 5-vinyl-2-norbornene, 2,5-norbornadiene, 7-methyl-2,5-norbornadiene, 7-ethyl-2,5-norbornadiene, 7-propyl-2,5-norbornadiene, 7-butyl-2,5-norbornadiene, 7-pentyl-2,5-norbornadiene, 7-hexyl-2,5-norbornadiene, 7,7-dimethyl-2,5-norbornadiene, 7,7-methylethyl-2 ,5-norbornadiene, 7-chloro-2,5-norbornadiene, 7-bromo-2,5-norbornadiene, 7-fluoro-2,5-norbornadiene, 7,7-dichloro-2,5-norbornadiene, 1-methyl -2,5-norbornadiene, 1-ethyl-2,5-norbornadiene, 1-propyl-2,5-norbornadiene, 1-butyl-2,5-norbornadiene, 1-chloro-2,5-norbornadiene, 1-bromo -2,5-norbornadiene and the like.
Moreover, the compound of the following structure can also be mentioned as a polyene.

One or more polyenes may be used, preferably 5-ethylidene-2-norbornene, dicyclopentadiene, 5-vinylnorbornene and norbornadiene.

Examples of vinyl aromatic compounds include styrene, o-methylstyrene, m-methylstyrene and p-methylstyrene. Examples of vinyl alicyclic compounds include vinylcyclohexane, vinylcycloheptane, and vinylcyclooctane. Examples of cyclic olefins include cyclohexene and 2-norbornene.

In the present invention, hydrogen is usually used as a molecular weight modifier for controlling the molecular weight of the resulting polymer. Hydrogen is fed to the reactor along with ethylene.

[Olefin polymer]
The olefin polymer that can be produced by the production method of the present invention is suitably used for applications such as base oil components of lubricating oils such as engine oils and viscosity modifiers. In addition, it can be used as a material for a molded product manufactured by a known method such as injection molding, extrusion molding, inflation molding, calender molding, or as a modifier.

The weight-average molecular weight of the olefin polymer according to the present invention is in the range of 1,000 to 20,000, preferably 1,000 to 17,000, more preferably 1,000 when used as a lubricating oil. to 15,000, particularly preferably 1,000 to 13,000. When it is in this range, it is excellent in thickening property and shear stability to the base oil when used in lubricating oil.

The molecular weight distribution (Mw/Mn) of the olefin polymer according to the present invention is 2.5 or less, preferably in the range of 1.1 to 2.5, more preferably in the range of 1.2 to 2.2. be. Within this range, the obtained lubricating oil composition has excellent shear stability.

The number average molecular weight and weight average molecular weight of the olefin polymer according to the present invention can be measured by gel permeation chromatography (GPC) calibrated using a standard substance (monodisperse polystyrene (PSt)) with a known molecular weight. , the molecular weight distribution (Mw/Mn) can be calculated from these results. When the molecular weight distribution is broad, the amount of higher and/or lower molecular weight components deviating from the desired molecular weight contained in the α-olefin (co)polymer increases, and the higher molecular weight components are shear stable for the reasons described above. reduce sexuality.

As the measurement conditions of GPC in the present invention, the conditions described in the Examples column are adopted.
In addition, the molecular weight of the olefin polymer according to the present invention is preferably 0.01 to 0.8 dl/g, more preferably 0.02 to 0.7 dl/g, and particularly preferably, when expressed in terms of intrinsic viscosity. is 0.03 to 0.6 dl/g. In the present invention, the intrinsic viscosity ([η]) of the copolymer is determined by measuring in decalin at 135° C. according to JIS K7367.

Among the olefin polymers according to the present invention, the ethylene-based copolymer obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms preferably contains 20 to 80 mol% of structural units derived from ethylene. More preferably 25 to 75 mol%, more preferably (30 to 70 mol%).Also preferably contains 20 to 80 mol% of α-olefin-derived structural units, more preferably 25 to It contains 75 mol%, more preferably 30 to 70 mol%.When the composition of each unit is within the above range, the obtained ethylene copolymer exhibits excellent temperature and viscosity characteristics as a lubricating oil. be able to.

Further, when the polymer obtained by the method for producing an olefin polymer of the present invention is used as a modifier or the like, the melt flow rate (MFR) of the polymer is not particularly limited, but is preferred. is 0.01 to 1000 g/10 minutes, more preferably 0.1 to 500 g/10 minutes, still more preferably 0.1 to 200 g/10 minutes, even more preferably 0.1 to 100 g/10 minutes, particularly preferably A range of 0.1 to 50 g/10 minutes is desirable. It is also preferable that the MFR of the olefin polymer is 2.0 or more.

In the present invention, the above MFR is a value measured with a load of 2.16 kg by the method of ASTM D1238. Although the measurement temperature varies depending on the type of resin, it is often measured at 190° C. for ethylene polymers and at 230° C. for propylene polymers. A measurement temperature of 260° C. or 280° C. may be used depending on the melting point and glass transition temperature of the polymer to be obtained.

When the above polymer is an ethylene-based copolymer obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms, it preferably contains 60 to 98 mol% of structural units derived from ethylene. more preferably 65 to 95 mol %, still more preferably 70 to 90 mol %. Such a composition tends to exhibit favorable performance as a modifier.

EXAMPLES The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[Example 1]
(Preparation of transition metal complex compound solution)
As the hafnium halide type complex compound (A), a hafnium halide type complex compound of the following structural formula, triisobutylaluminum as the organometallic compound (B), and n-hexane as the hydrocarbon compound (C) are used. The following proportions were mixed at room temperature in a metal vessel equipped with a stirrer, which was purged with nitrogen, to prepare a transition metal complex compound solution. The solution was stored at 5°C.

The metal element molar ratio [(A)/(B)] between the hafnium halide type complex compound (A) and the organometallic compound (B) in the transition metal complex compound solution is 1/20, and the hafnium halide type complex compound (A ) was 0.03 mmol/liter.
・Hexane: 90L
・ Triisobutylaluminum: 54 mmol-Al
・ Hafnium halide type complex compound: 2.7 mmol-Hf

(continuous polymerization)
Copolymerization of ethylene and 1-butene was carried out by the following method. Two transition metal complex compound solutions were used, 10 hours after preparation and 48 hours after preparation.

(Polymerization method)
A pressure-resistant reactor with an internal volume of 100 L with a stirring blade equipped with a jacket capable of temperature control, a line equipped with a compressor and a valve (sometimes referred to as a circulation line) that can circulate unreacted gas, a solvent (n-hexane) ) feed line, raw material gas (ethylene and hydrogen) feed line, 1-butene feed line, catalyst (in-line blending of the hafnium halide complex compound solution and the following boron-based cocatalyst) feed line, content (production ) Polymerization of ethylene and 1-butene was carried out using an apparatus equipped with a product extraction line. Among them, the feed lines for ethylene and hydrogen were configured to be connected to the above circulation line.
Polymerization temperature: 125°C
n-Hexane: 16 L / hour Transition metal complex compound solution: 0.007 mmol-Hf / hour Boron-based promoter (Note): 0.035 mmol / hour Ethylene: 7.0 kg / hour 1-butene: 4.5 kg / hour Hydrogen: 300 NL/hour Pressure: 3.5 MPa
Reaction liquid volume: Maintain 28L
(Note) Triphenylcarbenium tetrakis(pentafluorophenyl)borate

Polymerization under the above conditions yielded a production rate of 8 kg/hour, polymerization activity of 1100 kg/(mmol-Hf.hour), ASTM D1238, 2.16 kg load, MFR at 190°C of 10 g/10 min, density of An ethylene/1-butene copolymer of 860 kg/m ³ was obtained.

[Example 2]
(Transition metal complex compound) solution preparation)
As the hafnium halide type complex compound (A), a hafnium halide type complex compound of the following structural formula, triisobutylaluminum as the organometallic compound (B), and n-hexane as the hydrocarbon compound (C) are used. The following proportions were mixed at room temperature in a metal vessel equipped with a stirrer, which was purged with nitrogen, to prepare a transition metal complex compound solution. The solution was stored at 5°C.

The metal element molar ratio [(A)/(B)] between the hafnium halide type complex compound (A) and the organometallic compound (B) in the transition metal complex compound solution is 1/20, and the hafnium halide type complex compound (A ) was 0.08 mmol/liter.
・Hexane: 90L
・ Triisobutylaluminum: 144 mmol-Al
・ Hafnium halide type complex compound: 7.2 mmol-Hf

(continuous polymerization)
Copolymerization of ethylene and 1-butene was carried out by the following method. Two transition metal complex compound solutions were used, 10 hours after preparation and 300 hours after preparation. .

(Polymerization method)
A pressure-resistant reactor with an internal volume of 100 L with a stirring blade equipped with a jacket capable of temperature control, a line equipped with a compressor and a valve (sometimes referred to as a circulation line) that can circulate unreacted gas, a solvent (n-hexane) ) feed line, raw material gas (ethylene and hydrogen) feed line, butene feed line, catalyst (in-line blending of the hafnium halide complex compound solution and the following boron cocatalyst) feed line, content (product) Ethylene and 1-butene were polymerized using an apparatus equipped with an extraction line. Among them, the feed lines for ethylene and hydrogen were configured to be connected to the above circulation line.
Polymerization temperature: 125°C
n-Hexane: 31 L/hr Transition metal complex compound solution: 0.007 mmol-Hf/hr Boron-based promoter (Note): 0.035 mmol/hr Ethylene: 9.0 kg/hr 1-butene: 4.0 kg/ Time Hydrogen: 200 NL/hour Pressure: 3.4 MPa
Reaction liquid volume: Maintain 28L
(Note) Triphenylcarbenium tetrakis(pentafluorophenyl)borate

By operating under the above conditions, a production rate of 7 kg/hour, a polymerization activity of 1000 kg/(mimole-Hf.hour), ASTM 1238, a load of 2.16 kg, an MFR at 190°C of 9 g/10 min, and a density of An ethylene/1-butene copolymer of 885 kg/m ³ was obtained.

[Comparative Example 1]
(Transition metal complex compound) solution preparation)
Using n-hexane as the transition metal complex compound of the following structural formula as the hafnium halide complex compound (A) and n-hexane as the hydrocarbon compound (C), the compound is sufficiently nitrogen-substituted in a metal vessel equipped with a stirrer, and the following were mixed at room temperature to prepare a transition metal complex compound solution (triisobutylaluminum was not used as the organometallic compound (B)). The solution was stored at 5°C.

The metal element molar ratio [(A)/(B)] between the hafnium halide type complex compound (A) and the organometallic compound (B) in the transition metal complex compound solution becomes infinite.
・Hexane: 90L
・ Triisobutylaluminum: 0 mmol-Al
・Transition metal complex compound: 9.0 mmol-Hf

(continuous polymerization)
Copolymerization of ethylene and 1-butene was carried out under the following conditions. The used transition metal complex compound solutions were prepared under two conditions: 10 hours and 48 hours after preparation.

(Polymerization method)
A pressure-resistant reactor with an internal volume of 100 L with a stirring blade equipped with a jacket capable of temperature control, a line equipped with a compressor and a valve (sometimes referred to as a circulation line) that can circulate unreacted gas, a solvent (n-hexane) ) feed line, source gas (ethylene and hydrogen) feed line, butene feed line, catalyst feed line, content (product) extraction line, polymerization of ethylene and butene was carried out. . Among them, the feed lines for ethylene and hydrogen were configured to be connected to the above circulation line.
Polymerization temperature: 110°C
n-Hexane: 33 L/hr Transition metal complex compound solution: 0.007 mmol-Hf/hr Boron cocatalyst (Note): 0.035 mmol/hr Ethylene: 10 kg/hr 1-butene: 5.0 kg/hr Hydrogen : 15 NL/hour Pressure: 3.3 MPa
Reaction liquid volume: Maintain 28L
(Note) Triphenylcarbenium tetrakis(pentafluorophenyl)borate

Polymerization under the above conditions gave a production rate of 10 kg/hour when using a transition metal complex compound solution stored for 10 hours, polymerization activity: 1500 kg/mmol-Hf, ASTM 1238, 2.16 kg load, 190 ° C. An ethylene/1-butene copolymer having an MFR of 3 g/10 min and a density of 885 kg/m ³ was obtained.

However, when the solution stored for 48 hours was used, no polymerization reaction occurred and no polymer was obtained.
From the results of the above Examples and Comparative Examples, it can be seen that the transition metal complex compound solution of the present invention is a transition metal complex compound solution that has olefin polymerization activity even after being stored for a long period of time.

Claims (4)

A hafnium halide complex compound (A), an organometallic compound (B), and a hydrocarbon compound (C) are included, and the metal element molar ratio between the component (A) and the component (B) [(A)/(B )] is in the range of 1/1 to 1/500. 2. The method for storing a transition metal compound solution according to claim 1, wherein the hafnium halide type complex compound (A) is a metallocene compound (A'). 3. The method for storing a transition metal compound solution according to claim 1 or 2, wherein the organometallic compound (B) is an organoaluminum compound. A method for producing an olefin polymer, which comprises polymerizing an olefin using the transition metal compound solution according to any one of claims 1 to 3.

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