JP3201802B2 - Olefin polymerization method - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for polymerizing olefins. More specifically, it relates to a method for producing a polyolefin with high activity with a small amount of aluminoxane used.

[0002]

PRIOR ART Cyclopentadienyl group, indenyl group,
It is known that a transition metal compound having a fluorenyl group or a derivative thereof as a ligand, a so-called metallocene compound, can be used together with a cocatalyst such as an aluminoxane to polymerize an α-olefin to produce a poly-α-olefin. ing. JP-A-58-19309 and JP-A-60-35008 describe a method of polymerizing or copolymerizing an olefin in the presence of a catalyst composed of a metallocene compound and an aluminoxane. JP-A-61-130314, JP-A-64-6
Japanese Patent No. 6124 describes that a poly-α-olefin having a high degree of isotacticity can be produced by using a catalyst composed of a metallocene compound having a crosslinkable ligand and an aluminoxane. Japanese Patent Laid-Open No. 2-4130
No. 3, JP-A-2-274703, JP-A-2-
Japanese Patent No. 274704 describes that a syndiotactic poly-α-olefin can be produced by using a metallocene compound having a crosslinkable ligand composed of asymmetrical ligands and a catalyst composed of an aluminoxane.

On the other hand, the active species of the so-called Kaminsky type catalyst as described above is [Cp' ₂ MR] ⁺ (where Cp' = cyclopentadienyl derivative, M = Ti, Zr, Hf, R
= Alkyl), some catalyst systems that do not use aluminoxanes as co-catalysts have been reported since they were suggested to be transition metal cations. Taube et al.
Organometall. Chem., 347 , C9 (1988) [Cp ₂ T
Ethylene polymerization has been successful using a compound represented by iMe(THF)] ⁺ [BPh ₄ ] ^- (Me=methyl group, Ph=phenyl group). Jordan et al. J. Am. Chem. S
oc., 109 , 4111 (1987), [Cp ₂ ZrR(L)] ⁺
It is shown that zirconium complexes such as (R=methyl group, benzyl group, L=Lewis base) polymerize ethylene. Japanese Patent Publication No. 1-501950, Japanese National Publication No. 1-50
JP 2036 describes a method for polymerizing olefins using a catalyst composed of a cyclopentadienyl metal compound and an ionic compound capable of stabilizing a cyclopentadienyl metal cation. Zambelli et al. reported in Macromolecules, 22 , 2186 (1989) that isotactic polypropylene can be produced with a catalyst that combines a zirconium compound with a cyclopentadiene derivative as a ligand and trimethylaluminum and fluorodimethylaluminum. is doing. JP-A-3-179005 discloses an olefin polymerization catalyst comprising a) a neutral metallocene compound, b) aluminum alkyl, and c) Lewis acid. Further, it has been attempted to use an organic aluminum compound in combination to reduce the amount of aluminoxane used.
JP-A-63-89505, JP-A-63-89505
89506, JP-A-63-130601,
It is described in JP-A-2-22307.

[0004]

As described above, a catalyst system using an aluminoxane requires a large amount of expensive aluminoxane. Therefore, an attempt has been made to reduce the amount of aluminoxane used in combination with an alkylaluminum compound. ing. However, in order to obtain high polymerization activity in these catalyst systems, it was necessary to add an alkylaluminum compound in an amount equal to or more than the amount of aluminoxane used.

[0005]

[Means for Solving the Problems] The inventors of the present invention have earnestly studied a method for producing a polyolefin with high activity even when the amount of aluminoxane used is reduced, and as a result, it is obtained by reacting with a specific organometallic compound. The inventors have found that the above objects can be achieved by using a metallocene compound, and have completed the present invention. That is, the present invention relates to (A) a reaction product obtained by bringing the following components (a) and (b) into contact with each other, (a) the following general formulas (1) and (Chemical Formula 2)

[0006]

[Chemical 2] (Here, A ¹ and A ² represent a cyclopentadienyl group, an indenyl group, a fluorenyl group, or a derivative thereof, and A ¹ and A ² may be the same as or different from each other. A ³ , A ⁴ is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group, an arylalkyl group, a halogenated aryl group, or a carbon atom containing a hetero atom selected from oxygen, nitrogen, sulfur and silicon. A hydrogen group or a hydrogen atom, Q is a hydrocarbon group having 1 to 10 carbon atoms connecting A ¹ and A ² , or a hydrocarbon group containing silicon, germanium or tin, and A ³ and A ⁴ are mutually They may be linked to each other to form a ring structure between A ³ , A ⁴ and Q. R ¹ and R ² are a halogen atom, a hydrogen atom,
An alkyl group having 1 to 10 carbon atoms, a silicon-containing alkyl group, an aryl group having 6 to 20 carbon atoms, an alkylaryl group, and an arylalkyl group are shown, and at least one of R ¹ and R ² is a halogen atom. M is titanium, zirconium, or hafnium. (B) from lithium, sodium and potassium having a hydrocarbon group having 2 or more carbon atoms or a silicon-containing hydrocarbon group.
A method for polymerizing an olefin, which comprises polymerizing an olefin in the presence of a catalyst composed of an organometallic compound of a selected metal and (B) an aluminoxane.

In the general formula (Formula 1), A ¹ and A ² represent a cyclopentadienyl group, an indenyl group, a fluorenyl group, or a derivative thereof. Specific examples of A ¹ and A ² include cyclopentadienyl group, methylcyclopentadienyl group, dimethylcyclopentadienyl group, tetramethylcyclopentadienyl group, indenyl group, 3-methylindenyl group, fluorenyl. Group, 1-methylfluorenyl group, 2,7-di-t-butylfluorenyl group and the like. A ³ and A ⁴ are an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group, an arylalkyl group, a halogenated aryl group, or a hetero atom selected from oxygen, nitrogen, sulfur and silicon. It is a hydrocarbon group containing an atom or a hydrogen atom. Specific examples of A ³ and A ⁴ include a hydrogen atom, a methyl group, an ethyl group, a propyl group, a phenyl group, a toluyl group, a fluorophenyl group, a methoxyphenyl group and a benzyl group. Q is a hydrocarbon group having 1 to 10 carbon atoms connecting A ¹ and A ² , or a hydrocarbon group containing silicon, germanium or tin, preferably a hydrocarbon group or a silicon atom.
Also, A ³ , A ⁴ are connected to each other, and A ³ , A ⁴ , Q
May form a ring structure, and in such a case, the group formed by A ³ , A ⁴ and Q is, for example, a cyclopentylidene group, a cyclohexylidene group, a tetrahydropyran-4-ylidene group. And so on.
R ¹ and R ² are a halogen atom, a hydrogen atom, and a carbon number of 1 to 10.
Is an alkyl group, a silicon-containing alkyl group, an aryl group having 6 to 20 carbon atoms, an alkylaryl group, or an arylalkyl group, and at least one of R ¹ and R ² is a halogen atom. Preferred specific examples of R ¹ and R ² are a chlorine atom and a methyl group.

Suitable examples of the transition metal compound represented by the above general formula (1) include bis(cyclopentadienyl)zirconium dichloride and bis(pentamethylcyclopenta) as the transition metal compound having a non-bridging ligand. (Dienyl)
Zirconium dichloride, (cyclopentadienyl)
Transition metal compounds having a bridging ligand, such as (pentamethylcyclopentadienyl)zirconium dichloride, include ethylenebis(1-indenyl)zirconium dichloride and ethylenebis(4,5,6,7-tetrahydro-1-indenyl)zirconium. Dichloride, dimethylsilylenebis(methylcyclopentadienyl)zirconium dichloride, dimethylsilylenebis(dimethylcyclopentadienyl)zirconium dichloride, isopropylidene(cyclopentadienyl)(9-fluorenyl)zirconium dichloride, diphenylmethylene(cyclopentadiene) And zirconium compounds such as (enyl)(9-fluorenyl)zirconium dichloride,
In addition to the same hafnium compounds as described above, for example, JP-A-3-9913 and JP-A-2-131488,
JP-A-3-21607, JP-A-3-106907
Examples thereof include transition metal compounds described in Japanese Patent Publication No.

In addition to the above transition metal compounds, a transition metal compound having a fluorenyl group substituted with an alkyl group or the like, which has been previously filed by the present inventor (described in Japanese Patent Application No. 2-179563), as a ligand. Is preferably used.
Particularly, by introducing a bulky group such as a t-butyl group into the fluorenyl group, the stereoregularity of the polymer and the stability of the catalyst are improved. Specific examples of such a compound include, for example, isopropylidene (cyclopentadienyl)(2,7-di-t-butyl-9-fluorenyl)zirconium dichloride, cyclohexylidene (cyclopentadienyl)(2,7- Di-t-butyl-9-fluorenyl)zirconium dichloride, diphenylmethylene(cyclopentadienyl)(2,7-dit-butyl-9-fluorenyl)zirconium dichloride, methylphenylmethylene(cyclopentadienyl)(2,7 Examples thereof include zirconium compounds such as -di-t-butyl-9-fluorenyl)zirconium dichloride, and similar hafnium compounds. These compounds are isopropylidene (cyclopentadienyl)(2,7-dit)
Although a synthesis example of -butyl-9-fluorenyl)zirconium dichloride is shown, other compounds can be easily synthesized by a method according to this.

In the present invention, the component (b) is selected from lithium, sodium and potassium having a hydrocarbon group having 2 or more carbon atoms or a silicon-containing hydrocarbon group.
The organometallic compound of the spilled metal is specifically, for example,
Examples thereof include n-butyl lithium, t-butyl lithium, neopentyl lithium, phenyl lithium, benzyl lithium and trimethylsilylmethyl lithium. Preferred specific examples include neopentyl lithium, benzyl lithium, and trimethylsilylmethyl lithium, which do not have hydrogen at the β-position. It is generally known that a metallocene compound having halogen as a ligand is reacted with an organometallic compound of Group 1a or 2a of the periodic table as described above to produce a compound in which halogen is substituted with an alkyl group or the like. ing.
(For example, J. Organometal. Chem., 34 , 155 (1972), Or
ganometallics, 9 ,1539 (1990), Or-ganometallics, 1
0 , 1406 (1991), Organometallics, 10 ,3417 (1991)
Etc. However, the effect of reducing the amount of aluminoxane used as a cocatalyst by using these organometallic compounds and metallocene compounds in combination as in the present invention has not been found. The method of contacting the components (a) and (b) is not particularly limited, but in an organic solvent, -100 to 100
A method of contacting at a temperature of °C is preferably used. More preferably, in a hydrocarbon solvent such as benzene, toluene, pentane, hexane, heptane, -100 to 50°C.
The method of contacting with is used. The proportion of the component (b) used with respect to the component (a) is 1.0 to 100 times by mole, preferably 1.0 to 50 times by mole. The aluminoxane used in the present invention has a general formula (Chemical Formula 3).

[0011]

[Chemical 3] (Wherein R represents a hydrocarbon group having 1 to 10 carbon atoms, and n represents 2 or more), and particularly methylaluminoxane in which R is a methyl group, n is 5 or more, preferably 10 or more. Are used. The aluminoxane may be mixed with some alkylaluminum compound. In addition, in addition to the above, JP-A-2-24701
Aluminoxane having two or more kinds of alkyl groups described in JP-A No. 3-103407 and the like, fine-particle aluminoxane described in JP-A No. 63-198691, and JP-A No. 2-167302.
Aluminum oxy compounds and the like, which are obtained by contacting aluminoxane described in JP-A No. 2-167305 and water with an active hydrogen compound, can also be suitably used.

The ratio of the aluminoxane to be used in the present invention is 1 to 10000 mol times, usually 10 to 1000 mol times.

The polymerization method and polymerization conditions used in the method of the present invention are not particularly limited, and known methods used in the polymerization of α-olefins can be used. Solvent polymerization method using an inert hydrocarbon medium, or substantially A bulk polymerization method or a gas phase polymerization method in which an inert hydrocarbon medium does not exist can also be used, and it is general to carry out at a polymerization temperature of −100 to 200° C. and a polymerization pressure of normal pressure to 100 kg/cm ^2. .. The pressure is preferably −50 to 100° C. and atmospheric pressure to 50 kg/cm ² .

The hydrocarbon medium used in the treatment or polymerization of the catalyst component in the present invention includes, for example, saturated hydrocarbons such as butane, pentane, hexane, heptane, octane, nonane, decane, cyclopentane and cyclohexane, and benzene. Aromatic hydrocarbons such as, toluene, xylene, etc. can also be used. As the olefin used in the polymerization, ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-
Examples thereof include olefins having 2 to 25 carbon atoms such as tetradecene, 1-hexadecene and 1-octadecene. In the present invention, it can be used not only for homopolymerization of olefins but also for producing copolymers of olefins having about 2 to 25 carbon atoms such as propylene and ethylene, propylene and 1-butene.

[0015]

[Isopropylidene (cyclopentadiene) (2,7-di-t-butyl-9-fluorene)]

2 into a 300 cm ³ glass flask with sufficient nitrogen substitution.
12.0 g of 7-di-t-butyl-9-fluorene (Synth
sis, 335 (1984)) was dissolved in 100 cm ³ of tetrahydrofuran. To this solution, 44 mmol of a methyllithium ether solution was added dropwise at -78°C. After completion of dropping, raise the reaction solution to room temperature,
The mixture was stirred at the same temperature for 3 hours. To this reaction solution, 4.6 g of 6,6-dimethylfulvene diluted with 50 cm ³ of tetrahydrofuran was added dropwise at -78°C. After finishing the dropping
The reaction temperature was raised to room temperature and stirring was continued for another 10 hours. The reaction was stopped by adding 100 cm ^{3 of} 3.6% hydrochloric acid water, and the ether layer was washed with water and evaporated to dryness to obtain a reddish brown viscous liquid. The viscous liquid was recrystallized from hot acetone to give white powder of isopropylidene (cyclopentadiene) (2,7-di-t-butyl-9-
Fluorene) 12.2g was obtained. The physical properties of this compound are shown below. [Isopropylidene (cyclopentadienyl) (2,7
-Di-t-butyl-9-fluorenyl)zirconium dichloride] First, the isopropylidene (cyclopentadiene) (2,7-di-t-butyl-9-fluorene) 1 synthesized above.
By lithiation of 0.0 g with n-butyllithium, isopropylidene (cyclopentadiene) (2,
A dilithium salt of 7-di-t-butyl-9-fluorene) was prepared. Next, 6.1 g of zirconium tetrachloride was suspended in 100 cm ³ of methylene chloride in a 500 cm ³ glass flask that had been sufficiently replaced with nitrogen. Isopropylidene (cyclopentadienyl) melted in this suspension at -78°C
300 cm ³ of a solution of (2,7-di-t-butyl-9-fluorenyl)dilithium in methylene chloride was added at −78° C. After stirring at −78° C. for 4 hours, the temperature was slowly raised to room temperature and the reaction was continued at that temperature for another 15 hours. A reddish brown solution containing a white precipitate of lithium chloride was filtered off, and the filtrate was concentrated and then cooled at -30°C for 24 hours to give orange crystals of isopropylidene (cyclopentadienyl) (2,7-di-t- 4.3 g of butyl-9-fluorenyl)zirconium dichloride were obtained. The physical properties of this compound are shown below. Elemental analysis value C ₂₉ H ₃₄ ZrCl ₂ C H Cl calculated value (%) 63.97 6.25 13.0 measured value (%) 64.20 6.21 12.90

Polymerization First, 10 mg of isopropylidene(cyclopentadienyl)(2,7-di-t-butyl-9-fluorenyl)zirconium dichloride thus synthesized and trimethylsilylmethyl were placed in a 100 cm ³ glass flask purged with nitrogen. A pale yellow catalyst solution containing a small amount of a white precipitate was obtained by contacting 0.1 mmol of lithium in heptane at room temperature. Next, 1.5 dm with sufficient nitrogen substitution
³ of the prepared catalyst solution to the autoclave 5.5 × 10 ^-3 mmole at terms of Zr atom was charged with Tosoh Akzo Co. methylaluminoxane 30mg, liquid propylene 0.75Dm ³ added, 1 hour at 40 ° C. Polymerization was carried out.
After stopping the polymerization by adding a small amount of methanol to the system, unreacted propylene was purged and dried to obtain 32.8 g of syndiotactic polypropylene powder. The intrinsic viscosity ([η]) of the powder measured with a 135° C. tetralin solution is 0.95 dl/g,
^The syndiotactic pentad fraction (rrrr) measured by ¹³ C-NMR was 0.93.

Comparative Example 1 5.5×10 ⁻³ mmol of isopropylidene(cyclopentadienyl)(2,7-di-t-butyl-9-fluorenyl)zirconium dichloride synthesized in Example 1 as a catalyst and methylaluminoxane were used. except for using 30mg is a propylene polymerization was carried out in the same manner as the polymerization in example 1. As a result, only 10.1 g of syndiotactic polypropylene was obtained. [Η] of this polymer was 0.92 dl/g, and rrrr was 0.91.

Comparative Example 2 Isopropylidene (cyclopentadienyl) (2,7-di-t-butyl-9-fluorenyl) synthesized in Example 1
The reaction product obtained by reacting zirconium dichloride with 2 equivalents of methyllithium in heptane at room temperature in the same manner as in Example 1 was used as zircomium to give 5.5×10 ^−3.
Polymerization was carried out in the same manner as in Example 1 except that 30 mmol of methylaluminoxane and 30 mg of methylaluminoxane were used as the catalyst, and only 8.4 g of syndiotactic polypropylene was obtained. [Η] of this polymer is 0.90 dl/
g and rrrr were 0.90.

[0019]

By carrying out the method of the present invention, it is possible to produce a polyolefin with high activity with a small amount of aluminoxane used, which is extremely valuable industrially.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A 64-6003 (JP, A) JP-A 64-6005 (JP, A) JP-A 63-22804 (JP, A) JP-A 63- 168409 (JP, A) JP-A-5-170822 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 4/646 C08F 10/00-10/14

Claims (1)

(57) [Claims] 1. A reaction product obtained by contacting (A) the following components (a) and (b) with each other. (a) The following general formula (1) (Chemical formula 1) (Here, A ¹ and A ² represent a cyclopentadienyl group, an indenyl group, a fluorenyl group, or a derivative thereof, and A ¹ and A ² may be the same as or different from each other. A ³ , A ⁴ is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group, an arylalkyl group, a halogenated aryl group, or a carbon atom containing a hetero atom selected from oxygen, nitrogen, sulfur and silicon. A hydrogen group or a hydrogen atom, Q is a hydrocarbon group having 1 to 10 carbon atoms connecting A ¹ and A ² , or a hydrocarbon group containing silicon, germanium or tin, and A ³ and A ⁴ are mutually They may be linked to each other to form a ring structure between A ³ , A ⁴ and Q. R ¹ and R ² are a halogen atom, a hydrogen atom,
An alkyl group having 1 to 10 carbon atoms, a silicon-containing alkyl group, an aryl group having 6 to 20 carbon atoms, an alkylaryl group,
It represents an arylalkyl group, and at least one of R ¹ and R ² is a halogen atom. M is titanium, zirconium,
Hafnium. (B) from lithium, sodium and potassium having a hydrocarbon group having 2 or more carbon atoms or a silicon-containing hydrocarbon group.
An olefin polymerization method comprising polymerizing an olefin in the presence of a catalyst composed of an organometallic compound of a selected metal and (B) an aluminoxane.