JPH10292007A - Process and catalyst for producing polyolefin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a catalyst for the production of a poly-α-olefin having a low atactic component and highly stereoregular isotactic component by impregnating a magnesium halide with an organometallic compound and forming only a recemic modification structure of a zirconium metallocene compound on its surface. SOLUTION: The organometallic compound used is a compound of formula I (wherein R<1> and R<2> are each an organic liquid such as cyclopentadienyl, indenyl, fluorenyl or a derivative thereof; M<1> is a group IVB transition metal; and X<2> is a halogen). This is reacted with a halide of a group IVA metal (M<2> ) to obtain a compound represented by formula II (wherein M<1> is an element typified by a group IVB element; R<1> and R<2> are each as defined in formula I; M<2> is a group IVA transition metal element; and X<1> and X<2> are each a halogen). A magnesium halide is impregnated with the organometallic compound of formula II to obtain a catalyst for the production of a poly-α-olefin. This is combined with a promoter such as a water-modified organoaluminum compound of a trialkylaluminum compound of formula IV (wherein R<3> is a 1-10C alkyl).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a poly-.alpha.-olefin and a catalyst, and more particularly, to a poly-.alpha.-olefin having a structure having a small atactic component and a high stereoregularity in an isotactic portion. And more particularly to a catalyst for producing poly-α-olefins used therefor.

[0002]

2. Description of the Related Art Metal compounds having a cyclopentadienyl group, an isoenyl group, a fluorenyl group, or a derivative thereof as a ligand, so-called metallocene compounds, are used as cocatalysts such as aluminoxane or B (C ₆ F ₅ ) ₄ ^- by polymerizing α- olefins used with metallocene compounds cation ionic compound capable of stabilizing such as are known to poly -α- olefin can be produced. For example, JP-A-58-19309 describes a method for polymerizing or copolymerizing ethylene or α-olefin in the presence of a catalyst comprising a metallocene compound and an aluminoxane. JP-A-64-66124 discloses a transition metal compound having a cyclopentadienyl compound crosslinked with silicon as a ligand and a catalyst for producing a stereoregular olefin polymer containing an aluminoxane as an active ingredient. .

The poly-α obtained using these catalysts
-The stereoregularity of the olefin is derived from the stereostructure of the catalyst.A metallocene compound having a meso structure can provide an atactic polymer, and a metallocene compound having a racemic structure can provide an isotactic polymer. Are known. For this reason, RFJordan et al. To obtain only isotactic polymers from Organometallics, 14,
5 (1995) reported that only a racemate can be selectively synthesized using a zirconium amide compound as a precursor.

On the other hand, since the above-mentioned Kaminski type catalyst is soluble in the catalytic reaction system, the poly-α-olefin obtained by polymerization has a very low bulk density,
There was a disadvantage that the powder properties were poor.

In recent years, poly-α-olefins having a large bulk density and excellent powder properties can be obtained by a catalyst comprising an aluminoxane and a solid portion in which these metallocene compounds are supported on a fine-grained porous inorganic oxide. JP 6
It is described in Japanese Patent Application Laid-Open No. 1-276805 and Japanese Patent Application Laid-Open No. 63-89505.

Soga et al., Makromol, Chem., Rapid Commu.
n., 15, 139 (1994), a catalyst in which a solid portion of a zirconium compound having a cyclopentadiene derivative as a ligand supported on a silica gel surface using silicon and an aluminoxane or an organoaluminum compound was combined with a catalyst to provide a high melting point. Reported that an isotactic polypropylene was produced.

[0007]

However, in a catalyst system in which a solid portion in which these zirconium compounds are supported on silica using silicon and an organoaluminum compound is used, the catalyst structure is a mixture of a meso structure and a racemic structure. Thus, there is a problem that the resulting polymer is a mixture of an atactic polymer and an isotactic polymer.

Therefore, the present inventors constructed a racemic structure of a zirconium metallocene compound on the surface of a magnesium halide by using magnesium halide instead of silica gel, which is an inorganic oxide, to form an atactic polymer. The present inventors have made intensive studies to develop a catalyst capable of producing only an isotactic polymer without using the catalyst and a method for producing an α-olefin polymer using the catalyst.

[0009]

SUMMARY OF THE explain a result, the magnesium halide, the following general formula _{^{(1) rac-X 1 2}} M 1 R 1 R 2 M 2 X 2 2 (1) ( wherein, M ¹ is the typical elements of the periodic table group IVB, R ^1, R ² is a cyclopentadienyl group, an indenyl group, a fluorenyl group, or an organic ligand derivatives thereof, M ² is the periodic table
Group IVA transition metal elements, X ¹ and X ² represent halogen. )
A supported metallocene catalyst having only a racemic structure on a magnesium halide was successfully prepared by contacting an organometallic compound represented by the following formula. The organic ligand is a cyclopentadienyl group, an indenyl group, a fluorenyl group, or a derivative thereof, and a typical element of the IVB group is silicon, tin, or germanium. Is preferred. The transition metal element of the group IVA is preferably zirconium, and the halogen is preferably chlorine. The magnesium halide used in the present invention is not particularly limited, but preferably magnesium chloride is used. M ¹ is Si, M ² is Z
When r, X ¹ and X ² are Cl, R ¹ and R ² are indenyl groups and magnesium halide is magnesium chloride, the supported catalyst structure is considered to have a structure as shown in FIG.
The Cl atom on magnesium chloride and the halogen element bonded to the typical element seem to interact. As a result,
It is very unlikely that the metallocene portion of the supported catalyst will be released during the polymerization. Furthermore, since charge transfer from magnesium chloride to zirconium element occurs via silicon element and chlorine element, an increase in catalytic activity was also confirmed.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The organometallic compound represented by the above general formula (1) used in the catalyst of the present invention is represented by the following general formula (3) R ¹ R ² M ¹ X ² ₂ (3) In the formula, R ¹ , R ² , M ¹ , and M ² are the same as those described above), and can be obtained by reacting a halide of a metal (M ² ) of Group IVA of the periodic table with a metal halide represented by the formula

According to the method for producing a poly-α-olefin of the present invention, a catalyst for producing a poly-α-olefin comprising the organometallic compound represented by the above general formula (1), in particular, this organometallic compound is halogenated In the presence of a supported metallocene catalyst having only a racemic structure obtained by supporting on magnesium, the following general formula (4): AlR ³ ₃ (4) (where R ³ is an alkyl having 1 to 10 carbon atoms) A) represents a water-modified organoaluminum compound or an ionic compound containing a plurality of boron atoms obtained by modifying a trialkylaluminum compound represented by It is possible to obtain a polyolefin having a structure with less atactic component and high stereoregularity of an isotactic portion.

As the cocatalyst used in the present invention, methylaluminoxane, which is a compound of trimethylaluminum and water, is particularly preferable for a water-modified organoaluminum compound, and Ph ₃ C.B (C ₆ F _{5) for} an ionic compound. The boron-containing compound represented by ₄ ) is preferred.

The α-olefin used in the polymerization includes α-olefins having 3 to 25 carbon atoms such as propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene and 1-decene. Can be mentioned.

There are no particular restrictions on the type of polymerization method and polymerization conditions of the present invention, and any known method used for the polymerization of α-olefins may be used. For example, a solvent polymerization method using an inert hydrocarbon medium, or a bulk polymerization method substantially free of an inert hydrocarbon medium, a gas phase polymerization method can also be used, and the polymerization temperature is -100 ° C to 200 ° C, and the polymerization pressure is It is generally carried out at normal pressure to 100 kg / cm ² . Preferably, it is -50 to 150 ° C and normal pressure to 50 kg / cm ² .

The hydrocarbon medium used for the treatment or polymerization of the catalyst component in the present invention includes, for example, benzene, hexane, heptane, octane, nonane, decane, cyclopentane, cyclohexane and the like. Aromatic hydrocarbons such as toluene and xylene can also be used.

[0016]

The present invention will be specifically described below with reference to examples.

Synthesis Example (Synthesis of Organic Ligand) (1) Synthesis of (Ind) ₂ SiCl ₂ Indenylmagnesium bromide
bromide, C ₉ H ₇ MgBr) (8.8 g, 40 mmol) was dissolved in diethyl ether (200 cm ³ ), and silicon tetrachloride (3.4 g, 20 mmol) dissolved in diethyl ether was added thereto, followed by further stirring for 12 hours. Was done. Next, the reaction solution was concentrated and dried, pentane (200 cm ³ ) was added, and the solution was filtered to remove solid MgBrCl.The filtrate was concentrated and recrystallized to obtain (C ₉ H
₇ ) ₂ SiCl ₂ (5 g, 23.4 mmol) was obtained. Obtained (C ₉ H ₇ ) ₂ Si
Cl ₂ was identified by NMR, elemental analysis and the like.

(2) Synthesis of (Ind) ₂ SiMe ₂ Indenylmagnesium bromide (C ₉ H ₇ MgBr) (8.8 g, 40 mmol) was dissolved in diethyl ether (200 cm ³ ), and dichlorodimethylsilane dissolved in diethyl ether was added thereto. (dichlor
odimethylsilane, Me ₂ SiCl ₂ ) (3.4 g, 20 mmol) was added, and the mixture was further stirred for 12 hours. Next, the reaction solution was concentrated and dried, pentane (200 cm ³ ) was added, the solution was filtered to remove solid MgBrCl, and the filtrate was concentrated and recrystallized to give (C ₉ H ₇ ) ₂ SiMe ₂ (3.0 g, 17.3 mmol) was obtained. The obtained (C ₉ H ₇ ) ₂ SiMe ₂ was identified by NMR, elemental analysis and the like.

(3) rac-Cl ₂ Si (Ind) ₂ ZrCl ₂ (Ind) ₂ previously dissolved in toluene in a nitrogen atmosphere
A toluene solution of Zr (NMe ₂ ) ₄ (1.0 g, 3.7 mmol) was added to SiCl ₂ (1.2 g, 3.7 mmol), and the solution was vigorously rotated for 17 hours while maintaining the reaction temperature at 100 ° C. Add 3 more to this solution
Equivalent amount of trimethylchlorosillan
e) (1.2 g, 11.1 mmol) was added and the mixture was stirred at room temperature for 12 hours. After filtering the generated solid, the toluene solution part is concentrated and dried,
After removing excess trimethylchlorosilane, methylene chloride (CH ₂ Cl ₃ , 100 cm ³ ) was added again and recrystallized at −20 ° C. to obtain rac-Cl ₂ Si (Ind) ₂ ZrCl ₂ as an orange powder. (1.2 g, 49% yield).

(4) meso, rac-Me ₂ Si (Ind) ₂ ZrCl ₂ previously dissolved in THF (20 cm ³ ) in a nitrogen atmosphere.
To (Ind) ₂ SiMe ₂ (1.2 g, 4.0 mmol), 2 equivalents of BuLi (1.6 M hexane solution, 8.0 mmol, 5.0 cm ³ ) was added dropwise at 0 ° C., and then stirred at room temperature for 6 hours. Stirring after the end of ZrCl ₄ · 2THF
(1.5 g, 4.0 mmol) was added at -78 ° C, and the mixture was further stirred at room temperature for 12 hours. After the completion of the reaction, the reaction solution was concentrated and dried, toluene (100 cm ³ ) was added, the generated solid portion was filtered, and the filtrate and lithium chloride were separated. Then concentrate the solution part,
When cooled to −20 ° C., meso, rac-Me ₂ Si (Ind) ₂ ZrCl ₂
Was obtained as a yellow powder (0.3 g, 20% yield).

Production Example (Production of Catalyst) (1) Catalyst A (rac-Cl ₂ Si (Ind) ₂ ZrCl ₂ / MgCl ₂ ) (FIG. 1) Magnesium chloride / toluene suspension previously suspended in a nitrogen atmosphere Suspended liquid (7.5 g, 50 cm ³ ) and rac-Cl ₂ Si (Ind) ₂ Z
An rCl ₂ toluene solution (0.8 mmol, 20 cm ³ ) was stirred at room temperature for 12 hours. After the stirring, the magnesium chloride was washed 10 times with 100 cm ³ of toluene to remove free rac-Cl ₂ Si (Ind) ₂ ZrCl ₂ . After the washing was completed, the resultant was dried at 40 ° C. under reduced pressure for 4 hours. As a result, a catalyst (solid product) was obtained. The amount of zirconium supported was 0.02 mmol / g.

(2) Catalyst B (meso, rac-Me ₂ Si (Ind) ₂ ZrCl ₂ /
MgCl ₂ ) Prepared in the same manner as catalyst A. However, they differ in the following points. That is, rac-Cl ₂ Si (Ind) ₂ ZrCl ₂
so, changed to rac-Me ₂ Si (Ind) ₂ ZrCl ₂ . As a result of analysis of the recovered solid, the amount of zirconium supported was about 0.02 g / g of catalyst.
mmol.

(3) Catalyst C (SiO ₂ —O—Si (Ind) ₂ ZrCl ₂ ) A catalyst was synthesized by the method disclosed in Makromol. Chem., Rapid Commun., 15, 139 (1994). Its structure is assumed to be as shown in FIG. 10 g of silica gel calcined at 200 ° C. for 8 hours is suspended in 100 cm ³ of toluene.
(Ind) ₂ SiCl ₂ (3.3 g, 10.2 mmol) was added. This solution
Refluxed at 120 ° C. for 12 hours. Then BuLi (1.6 M hexane solution, 19.2 mmol, 12 cm ³ ) was added and the mixture was kept under vigorous stirring for 8 hours. Further ZrCl ₄ · 2 (TH to the mixture
F) (3.3 g, 8.6 mmol) was added at -78 ° C and the mixture was kept under vigorous stirring for 12 hours. Next, the solid portion was filtered under a nitrogen atmosphere, washed five times with a large amount of THF, and dried at 40 ° C. under reduced pressure for 4 hours. As a result, a catalyst (solid product) was obtained. The amount of zirconium supported was 0.03 mmol per 1 g of the catalyst.

Example 1 (Example of Polymerization Using Catalyst A) A predetermined amount of purified toluene and methylaluminoxane were charged in a 100 cm ³ stainless autoclave reactor equipped with an electromagnetic stirring bar under a nitrogen atmosphere, and the catalyst A was converted to zirconium. After adding 0.005 mmol in terms of atoms, 7 dm ³ of propylene was supplied to initiate polymerization. At this time, toluene was added so that methylaluminoxane was 25.0 mmol in terms of aluminum atoms, and the total amount of the polymerization solution was 30 cm ³ .

The polymerization was carried out at 40 ° C. for 6 hours, and the polymerization was terminated by adding methanol containing a small amount of hydrochloric acid. Next, the reaction solution was poured into a large excess of methanol, and the solid portion was filtered and washed with methanol, and then dried under reduced pressure. The obtained solid was extracted with boiling pentane for 12 hours to separate an atactic polymer part and an isotactic polymer part. The polymer yield was 1.16 g, the isotactic part (Isotactic Index) was 92 wt%, the melting point of the isotactic part was 142.9 ° C., and the weight average molecular weight (Mw) was 2
The molecular weight distribution [weight average molecular weight (Mw) / number average molecular weight (Mn)] was 2.7, and the isotactic pentaad (mmmm) was 92%.

Example 2 (Example of polymerization using catalyst A) Polymerization was carried out in the same manner as in Example 1 except that the promoter was Ph ₃ · B (C ₆ F ₅ ) ₄ 0.005 mmol. Table 1 shows the results.

Example 3 (Example of polymerization using catalyst A) Polymerization was carried out in the same manner as in Example 1 except that the promoter was 5.0 mmol of triisobutylaluminum ((C ₄ H ₉ ) ₃ Al). Table 1 shows the results.

Comparative Example 1 (Polymerization Example Using Catalyst B) Polymerization was carried out in the same manner as in Example 1 except that the polymerization catalyst was changed to Catalyst B. Table 1 shows the results.

Comparative Example 2 (Example of Polymerization Using Catalyst B) Polymerization was carried out in the same manner as in Comparative Example 1, except that the promoter was 5.0 mmol of triisobutylaluminum ((C ₄ H ₉ ) ₃ Al). Table 1 shows the results.

Comparative Example 3 (polymerization example using catalyst C) Polymerization was carried out in the same manner as in Example 1 except that the polymerization catalyst was catalyst C. Table 1 shows the results.

[0031]

[Table 1]

[0032]

As can be seen from the results in Table 1, according to the polymerization method using the catalyst of the present invention, the isotactic moiety
(Isotactic Index) A polyolefin having a very high (Isotactic Index) can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic structural view of a catalyst A of the present invention.

FIG. 2 is a schematic structural view of a catalyst C of a comparative example.

Claims (6)

[Claims] 1. A general formula _{^{(1) rac-X 1 2}} M 1 R 1 R 2 M 2 X 2 2 (1) ( in the following formula, M ¹ is a typical element of the periodic table Group IVB, R ¹ , R ² is an organic ligand of a cyclopentadienyl group, an indenyl group, a fluorenyl group, or a derivative thereof, and M ² is a periodic table.
Group IVA transition metal elements, X ¹ and X ² represent halogen. )
A catalyst for producing a poly-α-olefin, wherein the organometallic compound represented by the formula (1) is supported on magnesium halide. 2. An organometallic compound represented by the general formula (1) is represented by the following general formula (2): rac-Cl ₂ SiR ¹ R ² ZrCl ₂ (2) (wherein R ¹ and R ² are The catalyst for producing a poly-α-olefin according to claim 1, wherein the organic metal compound is a pentadienyl group, an indenyl group, a fluorenyl group, or an organic ligand of a derivative thereof. 3. The catalyst for producing a poly-α-olefin according to claim 1, wherein the magnesium halide is magnesium chloride. 4. The following general formula (3): R ¹ R ² M ¹ X ² ₂ (3) (wherein R ¹ and R ² are cyclopentadienyl, indenyl, fluorenyl, or derivatives thereof) And M ¹ represents a transition metal of Group IVB of the periodic table, and X ¹ and X ² represent halogen.)
To give an organometallic compound represented by the family of metal halide is reacted formula ^{(M 2) (1) rac} -X 1 2 M 1 R 1 R 2 M 2 X 2 2 (1), which A method for producing a catalyst for producing poly-α-olefins, wherein the catalyst is further reacted with magnesium halide. 5. The method for producing a catalyst for producing poly-α-olefin according to claim 4, wherein the magnesium halide is magnesium chloride. 6. In the presence of the catalyst for producing poly-α-olefin according to any one of claims 1 to 3, the following general formula (4) AlR ³ ₃ (4) (wherein R ³ is An alkyl group having 1 to 10 carbon atoms.) A water-modified organoaluminum compound obtained by modifying a trialkylaluminum compound represented by formula (1) with water or an ionic compound containing a plurality of boron atoms as a co-catalyst. -A method for producing an olefin polymer, comprising polymerizing an olefin.