JPH0794500B2 - Method for producing polyolefin - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polyolefin. More specifically, it relates to a method for efficiently producing a polyolefin using a catalyst composed of a novel transition metal compound and aluminoxane having characteristics.

[Prior art and its problems] Kaminsky catalyst, that is, bis (cyclopentadienyl)
A catalyst composed of zirconium dichloride or the like and an aluminoxane can polymerize an olefin with high activity, as disclosed in JP-A-58-19309, Makromol. Chem. Rapid Commun., 4
Volume, page 417 (1983). In addition, recently, a technique of using various transition metal compounds to adjust the molecular weight, the molecular weight distribution, and the copolymerizability is also known (Japanese Patent Laid-Open No. Sho 60).
-35008, JP60-35007, JP60-35006
Issue). It should be noted that although these patents describe that a transition metal compound having a substituted cyclopentadienyl group is used as a catalyst component, an example using a transition metal compound having a 2,3 and 4-substituted cyclopentadienyl group is shown. Not at all.

This conventional Kaminsky catalyst has a high activity, but only a polymer having a low molecular weight can be obtained, and there is a problem that the activity is remarkably reduced when producing a high molecular weight polymer.

As a result of repeated studies to solve the above problems, the present inventors have developed a novel transition metal compound consisting of a transition metal compound having a 2,3- and 4-substituted cyclopentadienyl group and a specific aluminoxane. The present inventors have found that the catalyst can produce a polymer having a high activity and a high molecular weight, and arrived at the present invention.

[Means for Solving Problems] That is, the present invention provides (1) (A) a transition metal compound, and (B) a general formula [I] or a general formula [II]. (However, m is a number of 4 to 20, and R ¹ represents a hydrocarbon group) A method for producing a polyolefin by polymerizing an olefin having 3 or more carbon atoms with a catalyst containing an aluminoxane as a component , (A) as a transition metal compound, a compound represented by the general formula [III] (▲ R ² _n ▼ -C ₅ H _5-n ) ₂ ZrX ₂ [III] (where ▲ R ² _n ▼ -C ₅ H _5-n is Represents a substituted cyclopentadienyl group, n is an integer of 2 to 4, R ² is a carbon atom of 1 to 1
5 is an alkyl group, X is a halogen atom, and when n is 2, the substituents are 1,3. The present invention relates to a method for producing a polyolefin, which comprises using a compound represented by

The transition metal compound (A) used as the catalyst component in the method of the present invention is a zirconium compound having two 2,3 and 4-substituted cyclopentadienyl groups and two halogen atoms. .

These compounds are novel compounds, and their production method is
It is obtained by reacting a 2-4 substituted alkylcyclopentadiene with a transition metal halide as exemplified in the examples below. Further, 3 to be substituted cyclopentadienyl group, 1,2,3- and 1,2,4- ▲ R ² ₃ ▼ -C ₅ but two H ₂ is present, but also includes any. R ² is a hydrocarbon group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group and a pentyl group, preferably a methyl group and an ethyl group. X is a halogen atom such as fluorine, chlorine, bromine or iodine, preferably chlorine.

Further, as the transition metal compound, specifically, bis (1,3
-Dimethylcyclopentadienyl) zirconium dichloride, bis (1,3-diethylcyclopentadienyl) zirconium dichloride, bis (1,3-dimethylcyclopentadienyl) zirconium dipromide, bis (1,2,3
-Trimethylcyclopentadienyl) zirconium dichloride, bis (1,2,3-trimethylcyclopentadienyl) zirconium dipromide, bis (1,2,4-trimethylcyclopentadienyl) zirconium dichloride, bis (1,2 , 4-Trimethylcyclopentadienyl) zirconium dipromide, bis (1,2,4-trimethylcyclopentadienyl) zirconium diiodide, bis (1,2,
4-trimethylcyclopentadienyl) zirconium difluoride, bis (1,2,3,4-tetramethylcyclopentadienyl) zirconium dichloride, bis (1,2,3,4
Examples thereof include zirconium compounds such as -tetramethylcyclopentadienyl) zirconium dipromide.

Of these compounds, preferably bis (1,3-dimethylcyclopentadienyl) zirconium dichloride,
Bis (1,2,4-trimethylcyclopentadienyl) zirconium dichloride, bis (1,2,3,4-tetramethylcyclopentadienyl) zirconium dichloride and the like are used.

The aluminoxane (B) which is another catalyst constituent used in the method of the present invention is the organoaluminum compound represented by the above general formula [I] or general formula [II]. R ¹ is a hydrocarbon group such as a methyl group, an ethyl group, a propyl group or a butyl group, and preferably a methyl group or an ethyl group. m is an integer of 4 to 20, preferably 6
Above all, 10 or more is particularly preferable. The production method of this kind of compound is known, and for example, trialkyl is added to a hydrocarbon medium suspension of a compound containing adsorbed water, a salt containing water of crystallization (copper sulfate hydrate, aluminum sulfate hydrate, etc.). The method of adding aluminum and making it react can be illustrated.

In the method of the present invention, the olefin used in the polymerization reaction is ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, It is an α-olefin such as 1-hexadecene, 1-octadecene, 1-eicosene, etc., and a mixed component of two or more kinds of these can also be subjected to polymerization. Furthermore, butadiene, 1,4-hexadiene, 1,4-pentadiene, 1,7-octadiene, 1,
It is also effective for copolymerizing α-olefins with dienes such as 8-nonadiene and 1,9-decadiene, or cyclic olefins such as cyclopropane, cyclobutene, cyclohexene, norbornene and dicyclopentadiene.

As the polymerization method, any of suspension polymerization, solution polymerization and gas phase polymerization is possible. As a polymerization solvent for liquid phase polymerization, butane, pentane, hexane, octane, decane, dodecane, hexadecane, octadecane and other aliphatic hydrocarbons, cyclopentane, methylcyclopentane, cyclohexane, cyclooctane and other alicyclic hydrocarbons Aromatic hydrocarbons such as hydrogen, benzene, toluene, xylene, and petroleum fractions such as gasoline, kerosene, and light oil are used.
Of these, aromatic hydrocarbons are preferable. The olefin pressure of the reaction system is atmospheric pressure to 50 kg / cm ² G, and the polymerization temperature is -50 ° C to 230 ° C, preferably -20 ° C to 200 ° C. The molecular weight at the time of polymerization can be controlled by known means, for example, selection of temperature or introduction of hydrogen.

In the method of the present invention, a mixture of both the transition metal compound (A) and the aluminoxane may be supplied to the reaction system, or both components (A) and (B) may be supplied to the reaction system. Good. In any case, the concentration in the polymerization system of both components, the molar ratio is not particularly limited, preferably in the transition metal concentration of 10 ^-4 ~ 10 ^-9 mol / l range, Al / metal atom The molar ratio of is preferably 100 or more, and particularly preferably 1000 or more.

[Effect of the Invention] According to the method of the present invention, which uses a transition metal compound having two 2,3 and 4-substituted cyclopentadienyl groups as a novel transition metal compound to be combined with aluminoxane, the following Examples and Comparative Examples As is clear from the above, a polymer having higher activity and higher molecular weight than the conventional catalyst system can be obtained. Moreover, the molecular weight distribution can be easily adjusted by using two or more of these novel transition metal compounds at the same time.

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

Catalyst Production Example 1 [Bis (1,2,4-trimethylcyclopentadienyl) zirconium dichloride] All reactions were carried out under an inert gas atmosphere. The reaction solvent used was previously dried. In a 500 ml glass reaction vessel, 1,2,4-trimethylcyclopentadiene (5.5 g, 51 mmol) was diluted with 150 ml of tetrahydrofuran to prepare a 15% solution of n-butyllithium / hexane.
36 ml was added dropwise. After stirring at room temperature for 1 hour, a white suspension of 1,2,4-trimethylcyclopentadienyllithium was cooled to 0 ° C and 5.9 g (25 mmol) of zirconium tetrachloride was added.
Was added in 5 portions. The reaction solution was slowly warmed to room temperature and stirred for 48 hours. The solvent was distilled off under reduced pressure from the yellow solution containing the white precipitate (LiCl), and then extracted with 300 ml of methylene chloride,
It was filtered. The yellow filtrate was concentrated, pentane was added, and-
Cooling to 30 ° C. gave 4.0 g of white crystals. Sublimation (130-140
After purification at ℃ / 1 mmHg), 3.5 g (yield 36%) of the desired product was obtained.
The melting point of this compound was 172-173 ° C.

Example 1 [Polymerization] Purified toluene (450 ml), methylaluminoxane (molecular weight: 909) 6.3 mmol, manufactured by Toyo Stoufer Chemical Co., Ltd., and bis (1 , 2,4-Trimethylcyclopentadienyl) zirconium dichloride 0.02
Mmol was sequentially added, and the temperature was raised to 50 ° C. Next, propylene was continuously introduced into this so that the total pressure was maintained at 8 kg / cm ² G, and polymerization was carried out for 1.5 hours. After the reaction, the catalyst component was decomposed with methanol, and the obtained polypropylene was dried. As a result, 260 g of atactic polypropylene was obtained. The catalytic activity is 95 kg / gZr · hr, and the molecular weight is
It was 13000.

Catalyst Production Example 2 [Bis (1,2,3,4-tetramethylcyclopentadienyl) zirconium dichloride] All reactions were carried out under an inert gas atmosphere. The reaction solvent used was previously dried. In a 500 ml glass reaction vessel, 1,2,3,4-tetramethylcyclopentadiene (2.5 g, 20 mmol) was added to 1,2-dimethoxyethane (1).
Dilute with 50 ml of n-butyllithium / hexane 15
% Solution of 15% was added dropwise. After stirring for 1 hour at room temperature, 1,2,
A white suspension of 3,4-tetramethylcyclopentadienyllithium was cooled to 0 ° C and 2.3 g (10
Mmol) was added in 5 portions. Heating the reaction solution,
The mixture was stirred under reflux for 72 hours. The solvent was distilled off under reduced pressure from the yellow solution containing white precipitate (LiCl), followed by extraction with 300 ml of methylene chloride and filtration. The yellow filtrate was concentrated, pentane was added, and -30
After cooling to ℃, 0.16g of white crystals were obtained. Sublimation (130-140
After refining (° C / 1 mmHg), 0.13 g (yield 3%) of the desired product was obtained. The melting point of this compound was 270-271 ° C.

Example 2 [Polymerization] 450 ml of purified toluene, 6.3 mmol of methylaluminoxane (molecular weight 909) manufactured by Toyo Stoufer Chemical Co., Ltd., and bis ( 0.02 mmol of 1,2,3,4-tetramethylcyclopentadienyl) zirconium dichloride was sequentially added, and the temperature was raised to 50 ° C. Then, propylene was continuously introduced into this so that the total pressure was maintained at 8 kg / cm ² G, and polymerization was carried out for 2 hours. After the reaction, the catalyst component was decomposed with methanol, and the obtained polypropylene was dried. This results in atactic polypropylene
260 g were obtained. The catalytic activity was 71 kg / gZr · hr and the molecular weight was 6500.

Catalyst Production Example 3 [Bis (1,3-dimethylcyclopentadienyl) zirconium dichloride] All reactions were carried out under an inert gas atmosphere. The reaction solvent used was previously dried. In a 500 ml glass reaction vessel, 1,3-dimethylcyclopentadiene 3.
4 g (36 mmol) was diluted with 150 ml of tetrahydrofuran, and 24 ml of a 15% solution of n-butyllithium / hexane was added dropwise at 0 ° C. After stirring at room temperature for 1 hour, a solution of 1,3-dimethylcyclopentadienyllithium was cooled to 0 ° C., and 3.5 g (15 mmol) of zirconium tetrachloride was added in 5 portions. The reaction solution was slowly warmed to room temperature and stirred for 48 hours. The solvent was distilled off under reduced pressure from the yellow solution containing white precipitate (LiCl), followed by extraction with 300 ml of methylene chloride and filtration. The yellow filtrate was concentrated, pentane was added, and the mixture was cooled to -30 ° C to obtain 1.7 g of white crystals. Sublimation (130-140 ℃ / 1mmH
g) After purification, 1.1 g (yield 22%) of the desired product was obtained. The melting point of this compound was 175 to 176 ° C.

Example 3 [Polymerization] 450 ml of purified toluene, 6.3 mmol of methylaluminoxane (molecular weight 909) manufactured by Toyo Stoufer Chemical Co., Ltd. and bis ( 0.03-mmol 1,3-dimethylcyclopentadienyl) zirconium dichloride was sequentially added, and the temperature was raised to 50 ° C. Then, propylene was continuously introduced into this so that the total pressure was maintained at 8 kg / cm ² G, and polymerization was carried out for 4 hours. After the reaction, the catalyst component was decomposed with methanol, and the obtained polypropylene was dried. As a result, 450 g of atactic polypropylene was obtained. The catalytic activity is 61 kg / gZr · hr, and the molecular weight is 5000.
Met.

Comparative Example 1 450 ml of purified toluene, Toyo Stoufer Chemical Co., Ltd. methylaluminoxane (molecular weight 909) 6.3 mmol, and bis (cyclopentadienyl) zirconium dichloride 0.02 mmol were sequentially placed in a sus autoclave with an internal volume of 1.51 which was sufficiently replaced with nitrogen. It was added and the temperature was raised to 50 ° C.
Then, propylene was continuously introduced into this so that the total pressure was maintained at 8 kg / cm ² G, and polymerization was carried out for 4 hours. After the reaction, the catalyst component was decomposed with methanol, and the obtained polypropylene was dried. As a result, 150 g of atactic polypropylene was obtained. The catalytic activity was 20 kg / gZr · hr and the molecular weight was 1300.

Comparative Example 2 In a sus autoclave with an internal volume of 1.51 that had been sufficiently replaced with nitrogen, purified toluene 450 ml, methylaluminoxane (molecular weight 909) 6.3 mmol and bis (pentamethylcyclopentadienyl) zirconium dichloride 0.02 mmol manufactured by Toyo Stoufer Chemical Co., Ltd. Are added sequentially, and at 50 ℃
The temperature was raised to. Then add propylene to this at a total pressure of 8 kg / cm
^It was continuously introduced so as to maintain ² G and polymerization was carried out for 4 hours. After the reaction, the catalyst component was decomposed with methanol, and the obtained polypropylene was dried. As a result, 210 g of atactic polypropylene was obtained. Catalytic activity is 28kg / gZr
-Hr and the molecular weight was 300.

Comparative Example 3 450 ml of purified toluene, 6.3 mmol of methylaluminoxane (molecular weight 909) and 0.02 mmol of bis (methylcyclopentadienyl) zirconium dichloride manufactured by Toyo Stoufer Chemical Co., Ltd. were placed in a sus autoclave with an internal volume of 1.51 which had been sufficiently replaced with nitrogen. Sequentially added, the temperature was raised to 50 ° C. Then, propylene was continuously introduced into this so that the total pressure was maintained at 8 kg / cm ² G, and polymerization was carried out for 4 hours.
After the reaction, the catalyst component was decomposed with methanol, and the obtained polypropylene was dried. As a result, 220 g of atactic polypropylene was obtained. The catalytic activity was 30 kg / gZr · hr and the molecular weight was 800.

Comparative Example 4 In a sus autoclave with an internal volume of 1.51 which was sufficiently replaced with nitrogen, purified toluene 450 ml, methylaluminoxane (molecular weight 909) 6.3 mmol manufactured by Toyo Stoufer Chemical Co., Ltd. and bis (t-butylcyclopentadienyl) zirconium dichloride 0.02. Mmol was sequentially added, and the temperature was raised to 50 ° C. Next, propylene was added to this at a total pressure of 8 kg / cm ²
It was continuously introduced so as to maintain G, and polymerization was carried out for 4 hours. After the reaction, the catalyst component was decomposed with methanol, and the obtained polypropylene was dried. As a result, 160 g of atactic polypropylene was obtained. Catalytic activity is 22kg / gZr
It was hr and the molecular weight was 500.

Catalyst Production Example 4 [Bis (1,2,3-trimethylcyclopentadienyl) zirconium dichloride] All reactions were carried out under an inert gas atmosphere. The reaction solvent used was previously dried. In a 500 ml glass reaction vessel, 1,2,3-trimethylcyclopentadiene (3.5 g, 32 mmol) was diluted with 150 ml of tetrahydrofuran to prepare a 15% solution of n-butyllithium / hexane.
ml was added dropwise. After stirring at room temperature for 1 hour, a white suspension of 1,2,3-trimethylcyclopentadienyllithium was added to 0.
After cooling to ℃, 3.7 g (16 mmol) of zirconium tetrachloride was added in 5 portions. The reaction solution was slowly warmed to room temperature and stirred for 3 hours. After distilling off the solvent under reduced pressure from the yellow solution containing white precipitate (LiCl), the product was sublimated (130-140 ° C).
/ 1mmHg) 0.68g (11% yield) of purified white crystal target product
Got The melting point of this compound was 252-253 ° C.

Example 4 [Polymerization] 450 ml of purified toluene, 6.3 mmol of methylaluminoxane (molecular weight 909) manufactured by Toyo Stoufer Chemical Co., Ltd., and bis ( 1,2,3-Trimethylcyclopentadienyl) zirconium dichloride 0.
02 mmol was sequentially added, and the temperature was raised to 50 ° C. Then, propylene was continuously introduced into this so that the total pressure was maintained at 8 kg / cm ² G, and polymerization was carried out for 4 hours. After the reaction, the catalyst component was decomposed with methanol, and the obtained polypropylene was dried. As a result, 180 g of atactic polypropylene was obtained. The catalytic activity is 25 kg / g Zr · hr and the molecular weight is 56.
It was 00.

[Brief description of drawings]

FIG. 1 is a flow sheet illustrating the method of the present invention.

Front page continued (72) Inventor Takaya Mise 21-11, Suwa-cho, Kawagoe City, Saitama Prefecture (72) Inventor Hiroshi Yamazaki 2-41-10, Matsugaoka, Tokorozawa City, Saitama Prefecture (56) Reference JP-A-60-35007 (JP, A)

Claims (3)

[Claims] 1. A transition metal compound, and (B) a general formula [I] or a general formula [II]. (However, m is a number of 4 to 20, and R ¹ represents a hydrocarbon group) A method for producing a polyolefin by polymerizing an olefin having 3 or more carbon atoms with a catalyst containing an aluminoxane as a component , (A) a transition metal compound represented by the general formula [III] (▲ R ² _n ▼ -C ₅ H _5-n ) ₂ ZrX ₂ [III] (where ▲ R ² _n ▼ -C ₅ H _5-n is Represents a substituted cyclopentadienyl group, n is an integer of 2 to 4, R ² is a carbon atom of 1 to 1
5 is an alkyl group, X is a halogen atom, and when n is 2, the substituents are 1,3. ] The manufacturing method of the polyolefin characterized by using the compound represented by these. 2. The method according to claim 1, wherein the transition metal compound (A) is a compound having two trisubstituted cyclopentadienyl groups. 3. The method according to claim 1, wherein the transition metal compound (A) is a compound having two 4-substituted cyclopentadienyl groups.