JP2735658B2 - Novel transition metal compound and method for producing the same - Google Patents

Description

The present invention relates to a transition metal compound of Group IVB of the periodic table having a cycloalkylidene (cyclopentadienyl-1-fluorenyl) group as a ligand. The compound of the present invention is useful as a catalyst component for syndiotactic poly-α-olefin production.

[Conventional technology]

Vanadium compounds have long been known as catalyst components for producing syndiotactic poly-α-olefins. However, a polymer obtained by using a conventional vanadium compound as a catalyst comprising an organoaluminum has a poor syndiotacticity and a syndiotactic poly-α.
-It was hard to say that it was characteristic of olefins.

On the other hand, isopropylidene (cyclopentadienyl-1-fluorenyl) group is used as a catalyst component by JAEmen et al. As a catalyst component capable of producing polypropylene having good tacticity such that the syndiotactic pentad fraction exceeds 0.8. Has been synthesized. (J. Am. Chem., Soc., 1988.110.6255-6256) However, a transition metal compound having a cycloalkylidene (cyclopentadienyl-1-fluorenyl) group as a ligand has not been synthesized.

JP-A-64-66214 discloses that a compound having at least one fluorenyl group as a ligand is used as a catalyst for olefin polymerization. However, the disclosed compound may be a syndiotactic poly-α-olefin. Can not.

[Problems to be solved by the invention]

The transition metal compound having a ligand of an isopropylidene (cyclopentadienyl-1-fluorenyl) group according to JAEwen et al., When used as a polymerization catalyst for propylene in combination with aluminoxane, has good activity and high syndiotactic activity. Although it is an excellent compound from which Titicity polypropylene can be obtained, the catalyst is unstable, and a mixture of a transition metal compound and an aluminoxane has a problem that its activity decreases with time.

[Means for solving the problem]

Means for Solving the Problems The present inventors have solved the above-mentioned problems and have intensively studied to synthesize a novel compound useful as a catalyst component capable of producing a syndiotactic poly-α-olefin with high activity, and completed the present invention.

That is, the present invention succeeds in obtaining a transition metal compound of Group IVB of the periodic table having a cycloalkylidene (cyclopentadienyl-1-fluorenyl) group as a ligand by a synthesis route described later, and It was also confirmed by polymerization experiments that it was useful as a catalyst component for syndiotactic poly-α-olefin production.

The transition metal compound in the present invention has the general formula (I) (Where A ¹ is a cyclopentadienyl group, A ² is a fluorenyl group, A ³ is a cycloalkylidene group having 4 to 10 carbon atoms, and R ¹ and R ² are an aryl group or an alkyl group , A cycloalkyl group, or a halogen atom, a hydrogen atom, or a silyl group, and M is titanium, zirconium, or hafnium).

Further, the present invention relates to (2) cycloalkylidene (cyclopentadiene-1-
Fluorene) (3) cycloalkylidene (cyclopentadiene-1-)
Fluorene) is converted into a dialkali metal, and further reacted with a tetrahalide of a transition metal selected from titanium, zirconium, and hafnium to obtain a compound represented by general formula (II) (Where A ¹ is a cyclopentadienyl group, A ² is a fluorenyl group, A ³ is a cycloalkylidene group having 4 to 10 carbon atoms. Further, X ¹ and X ² are halogen atoms, M is titanium,
A method for synthesizing a transition metal halide of Group IVB of the periodic table having a cycloalkylidene (cyclopentadienyl-1-fluorenyl) group as a ligand represented by zirconium or hafnium.

(4) The compound of the general formula (2) is reacted with a general formula RLi (where R represents a hydrocarbon group having 1 to 10 carbon atoms) to form a compound of the general formula (I
A method for synthesizing a derivative of the general formula (II) wherein at least one of X ¹ or X ^{2 in} I) is substituted with R.

 It is intended for.

The synthesis route of the transition metal compound according to the invention of the present invention is, for example, cyclohexylidene (cyclopentadienyl-
The case where a ligand is a (1-fluorenyl) group is shown as follows.

_{C 13 H 10 + MeLi → LiC} 13 H 9 + CH 4 ...... (1) LiC 13 H 9 + C 6 H 10 = C 5 H 4 + HCl → C 6 H 10 (C 5 H 5) C 13 H 9 + LiCl ...... ( 2) C ₆ H ₁₀ (C ₅ H ₅ ) C ₁₃ H ₉ +2 BuLi → Li ₂ [C ₆ H ₁₀ (C ₅ H ₄ ) C ₁₃ H ₈ ] …… (3) Li ₂ [C ₆ H ₁₀ (C _{5 H 4) C 13 H 8} ] + MX 4 → [C 6 H 10 (C 5 H 4) C 13 H 8] MX 2 ...... (4) ( where X is a halogen atom, M is titanium, zirconium The production method of 6,6-pentamethylenefulvene used in the above reaction formula (2), that is, C ₆ H ₁₀ CC ₅ H ₄ is known.
(J. Org. Chem., 1984.49.1849-1853).

The novel cyclohexylidene (cyclopentadiene-1-fluorene) obtained by the formula (2), that is, C ₆ H ₁₀ (C
₅ H ₅₎ C ₁₃ H ₉ is And useful as an intermediate for synthesizing the novel transition metal compound of the present invention.

Similar to cyclohexylidene (cyclopentadiene-1-fluorene), cycloalkylidene having 4 to 10 carbon atoms (cyclopentadiene-1-fluorene) such as cyclobutenylidene (cyclopentadiene-1-fluorene), cyclodecanylidene ( Cyclopentadiene-1-
Fluorene) can also be synthesized.

A method for synthesizing a transition metal compound having cyclohexylidene (cyclopentadiene-1-fluorene) obtained according to the above reaction route as a ligand will be described below.

Such dialkyl metallization of cycloalkylidene (cyclopentadiene-1-fluorene) can be performed by reacting cycloalkylidene (cyclopentadiene-1-fluorene) with an alkali metal or organic alkali metal compound. As the solvent used at that time, ethers such as diethyl ether, tetrahydrofuran, and dimethoxyethane, and saturated hydrocarbon compounds such as heptane, hexane, and pentane can be used. The use ratio of the alkali metal or organic alkali metal compound to cycloalkylidene (cyclopentadiene-1-fluorene) is 2.0 to 10.0, preferably 2.0 to 4.0, and the reaction temperature is -100 to 150 ° C, preferably -90 ° C to 90. ° C
Range.

For example, cycloalkylidene (cyclopentadiene-1-fluorene) is dilithiated with alkyllithium by the above method to obtain cycloalkylidene (cyclopentadienyl-1-fluorenyl) dilithium, which is used in the next reaction.

Examples of the solvent used in the reaction of Li ₂ [A ₃ (C ₅ H ₄ ) C ₁₃ H ₈ ] with MX ₂ include halogenated hydrocarbons such as chloroform and methylene chloride, pentane, hexane, heptane, cyclohexane and the like. , Aromatic hydrocarbons such as benzene, toluene, and xylene, and ethers such as diethyl ether and tetrahydrofuran.

When performing the reaction, the molar ratio of Li ₂ [A ₃ (C ₅ H ₄ ) C ₁₃ H ₈ ] / MX ₄ is 0.9 to 3.0, preferably 1.0 to 1.5. The reaction temperature is-
The temperature ranges from 100 ° C to 100 ° C, preferably from -90 ° C to 50 ° C.
In the [A ₃ (C ₅ H ₄ ) C ₁₃ H ₈ ] MX ₂ (X is a halogen atom), X is a general formula RLi (where R represents a hydrocarbon group having 1 to 10 carbon atoms). The compound is easily substituted with an alkyl group by reacting with an organolithium compound represented by the formula (1), for example, an alkyllithium such as methyllithium.

As the solvent used at that time, for example, halogenated hydrocarbons such as chloroform and methylene chloride, pentane, hexane, heptane, saturated hydrocarbons such as cyclohexane, benzene, toluene, aromatic hydrocarbons such as xylene, diethyl Ethers such as ether and tetrahydrofuran can also be used. The _{[A 3 (C 5 H 4} ) C 13 H 8] when performing the reaction using the molar ratio of RLi against MX ₂ is 1.0 to 10.0, preferably 1.0 to 3.0. Reaction temperature is -1
It is in the range of 00 ° C to 100 ° C, preferably -90 ° C to 80 ° C.

The produced compound (I) can be purified by recrystallization or sublimation.

According to the above method, cycloalkylidene (cyclopentadiene-1-fluorene) having 4 to 10 carbon atoms, for example, cyclobutenidene ((cyclopentadiene-1-fluorene), cyclohexylidene (cyclopentadiene-1-fluorene)
Various transition metal compounds having fluorene), cyclodecanelidene (cyclopentadiene-1-fluorene) or the like as a ligand can be synthesized.

The transition metal compound (I) in the present invention produces a syndiotactic poly-α-olefin with high activity by polymerizing an α-olefin with an aluminoxane, and is extremely valuable as a polymerization catalyst component. The aluminoxane used for the polymerization has a general formula (Where R is a hydrocarbon group having 1 to 4 carbon atoms), in particular, methylaluminoxane wherein R is a methyl group, wherein n is 5 or more, preferably n is 10
The above are used.

A method for producing the above aluminoxane is known, and is, for example, a method for producing a salt by adding a trialkylaluminum to a salt containing water of crystallization (eg, copper sulfate hydrate, magnesium chloride hydrate) in a hydrocarbon solvent and reacting the salt. Can be exemplified.

The use ratio of the aluminoxane to the transition metal compound in the present invention is 10 to 10,000 mol times, usually 50 to 5000.
It is molar times. The polymerization conditions are not particularly limited, and a solvent polymerization method using an inert hydrocarbon medium, a bulk polymerization method substantially free of an inert hydrocarbon medium, and a gas phase polymerization method can be used. In general, the polymerization is carried out at a temperature of -100 to 200 ° C. and at a pressure of normal pressure to 100 kg / cm ² . Preferably, it is -50 ° C to 100 ° C and normal pressure to 50 kg / cm ² .

As the hydrocarbon medium used in the polymerization, for example, in addition to saturated hydrocarbons such as butane, pentane, hexane, heptane, octane, nonane, decane, cyclopentane, and cyclohexane, aromatic hydrocarbons such as benzene, toluene, and xylene are also included. Can be used.

As the α-olefin used in the polymerization reaction,
Ethylene, propylene, 1-butene, 4-methyl-1-
Pentene, 1-hexene, 1-octene, 1-decene,
1-dodecene, 1-tetradecene, 1-hexadecene,
Examples thereof include α-olefins having 2 to 25 carbon atoms such as 1-octadecene.

In the present invention, the transition metal compound is effective not only for the homopolymerization of the above-mentioned α-olefin but also for the production of a copolymer of two or more of these α-olefins as long as it exhibits a syndiotactic structure.

〔Example〕

 Hereinafter, the present invention will be specifically described with reference to examples.

Example 1 [Cyclohexylidene (cyclopentadiene-1-fluorene)] 11.4 g of fluorene was dissolved in 150 ml of tetrahydrofuran in a 300 ml glass flask which was sufficiently purged with nitrogen.
To this solution, 70 mmol of an ether solution of methyllithium was added dropwise at -78 ° C. After completion of the dropwise addition, the reaction solution was raised to room temperature, and stirred at that temperature for 3 hours. 10 g of 6,6-pentamethylenefulvene diluted with 50 ml of tetrahydrofuran was added to this reaction solution (J. Org, Chem., 1984.49.1849-1853).
(Synthesized according to the method described in). After completion of the dropwise addition, the reaction temperature was raised to room temperature, and stirring was continued for another 10 hours. The reaction was stopped by charging 200 ml of 3.6% aqueous hydrochloric acid, and the ether layer was washed with water and evaporated to dryness to obtain a yellow-white solid. This solid was washed with 100 ml of acetone to obtain 12.4 g of white cyclohexylidene (cyclopentadiene-1-fluorene). The physical properties of this compound are shown below.

Elemental analysis value C ₂₄ H ₂₄ CH Calculated value (%): 92.31 7.69 Actual value (%): 92.22 7.72 ¹ H-NMR: FIG. 1 [Cyclohexylidene (cyclopentadienyl-1-fluorenyl) zirconium chloride] The dilithium salt of cyclohexylidene (cyclopentadiene-1-fluorene) was prepared by lithiating the synthesized cyclohexylidene (cyclopentadiene-1-fluorene) with n-butyllithium.
Next, 5.5 g of zirconium tetrachloride was suspended in 100 ml of methylene chloride in a 500 ml glass flask sufficiently purged with nitrogen.
300 ml of a methylene chloride solution of cyclohexylidene (cyclopentadienyl-1-fluorenyl) dilithium dissolved at -78 ° C was introduced into the suspension at -78 ° C. −78
After stirring at 4 ° C. for 4 hours, the temperature was raised to room temperature, and the reaction was continued at that temperature for another 15 hours. The reddish-brown solution containing the white precipitate of lithium chloride was filtered off, and the reddish-brown filtrate was concentrated.
After cooling for 2.3 hours, 2.3 g of red crystals of cyclohexylidene (cyclopentadienyl-1-fluorenyl) zirconium dichloride was obtained.

The physical properties of this compound are shown below.

Elemental analysis value C ₂₄ H ₂₂ ZrCl ₂ CHCl Calculated value (%): 61.00 4.66 15.00 Actual value (%): 60.98 4.66 15.01 ¹ H-NMR: FIG. 2 Example 2 [Preparation of catalyst mixture] 100 ml of glass After replacing the flask with nitrogen, 10 mg of cyclohexylidene (cyclopentadienyl-1-fluorene) zirconium dichloride synthesized in Example 1 was dissolved in 10 ml of toluene. A purple catalyst solution was prepared by adding 1.2 g of methylaluminoxane (degree of polymerization 16.1) manufactured by Tosoh Akzo Co., Ltd. to this solution.

[Polymerization method] After replacing 2 l of autoclave with nitrogen, toluene 1 was added.
The catalyst solution prepared in Example 1 was charged and converted to Zr atoms,
0.0046 mmol was added. Add 3 kg /
Polymerization was carried out at 20 ° C. for 2 hours while maintaining cm ² . After the polymerization, the slurry was taken out and dried by filtration to obtain 98.5 g of syndiotactic polypropylene. Further, even when the filtrate was distilled off under reduced pressure to remove the solvent, the amount of the component soluble in toluene was 0.1 g. The intrinsic viscosity (hereinafter abbreviated as η) of the powder measured with a tetralin solution at 135 ° C. was 1.45 dl / g, and the syndiotactic pendat fraction was 0.90.

When the above-mentioned catalyst mixture was stored at room temperature for 24 hours and then polymerized in the same manner, the obtained polymer was 95.3 g of toluene-insoluble matter and 0.1 g of toluene-soluble matter. Did not change.

Comparative Example 1 [Catalyst Preparation] Isopropylidene (cyclopentadienyl-1-fluorenyl) zirconium chloride obtained by lithiating isopropylidene (cyclopentadiene-1-fluorene) synthesized according to a conventional method and reacting with zirconium tetrachloride. 10 mg was dissolved in 10 ml of toluene. A purple catalyst solution was prepared by adding 1.3 g of methylaluminoxane to this solution.

[Polymerization method] Polymerization was carried out in the same manner as in [Polymerization method] of Example 1, except that the catalyst mixture prepared above was used. The obtained polymer had a toluene-soluble content of 106.1 g and a toluene-insoluble content of 2.3 g. The η of the powder was 1.38 dl / g, and the pendat fraction of syndiotactic was 0.91.

However, when the catalyst mixture was stored at room temperature for 24 hours and used as in Example 1, the polymer obtained was 15.0 g of toluene-insoluble matter and 0.4 g of toluene-soluble matter. Thus, it is extremely unstable as compared with the catalyst of Example 1.

〔The invention's effect〕

Syndiotactic poly-α with stable performance by using the transition metal compound in the present invention as a catalyst component
It is capable of producing olefins and is of great industrial value.

[Brief description of the drawings]

FIG. 1 is a ¹ H-NMR spectrum of cyclohexylidene (cyclopentadiene-1-fluorene) of the present invention, FIG.
The figure shows cyclohexylidene (cyclopentadienyl-1-
¹ shows the ¹ H-NMR spectrum of (fluorenyl) zirconium dichloride.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 4/64 C08F 4/64 10/00 10/00

Claims (4)

(57) [Claims] 1. The compound of the general formula (I) (Where A ¹ is a cyclopentadienyl group, A ² is a fluorenyl group, A ³ is a cycloalkylidene group having 4 to 10 carbon atoms. R ¹ and R ² are an aryl group, an alkyl group, An alkyl group, a halogen atom, a hydrogen atom, or a silyl group, wherein M is titanium, zirconium, or hafnium, and a cycloalkylidene (cyclopentadienyl-1-fluorenyl) group as a ligand; Table IVB Group transition metal compounds. 2. Cycloalkylidene (cyclopentadiene-1-fluorene) 3. A method according to claim 1, wherein the cycloalkylidene (cyclopentadiene-1-fluorene) is converted into a dialkali metal, and further reacted with a tetrahalide of a transition metal selected from titanium, zirconium and hafnium to obtain a compound of the general formula (II) (Where A ¹ is a cyclopentadienyl group, A ² is a fluorenyl group, A ³ is a cycloalkylidene group having 4 to 10 carbon atoms. Further, X ¹ and X ² are halogen atoms, M is titanium,
A method for synthesizing a transition metal halide of Group IVB of the periodic table having a cycloalkylidene (cyclopentadienyl-1-fluorenyl) group as a ligand represented by zirconium or hafnium. 4. A compound of the general formula (II) is reacted with a general formula RLi (wherein R represents a hydrocarbon group having 1 to 10 carbon atoms), and at least one of X ^{1 and} X ² in the general formula (II) is reacted. A method for synthesizing a derivative of the general formula (II) in which one is substituted with R.