JP3142933B2 - Method for producing polyolefin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polyolefin. More specifically, the present invention relates to a method for producing a polyolefin using a catalyst comprising a transition metal compound having a group having a conjugated π electron as a ligand using a hydrous magnesium halide compound as a carrier and an organometallic compound having a hydrocarbon residue. .

[0002]

2. Description of the Related Art A method using a catalyst comprising a transition metal, an organoaluminum, and an organic acid ester as a polymerization catalyst for .alpha.-olefins has been proposed in Japanese Patent Publication No. 39-12105, and many improved catalysts have been proposed. Thus, both the catalytic activity and the stereoregularity of the obtained polymer are greatly improved.

For example, a catalyst system comprising a combination of titanium trichloride containing no aluminum and an organic titanium compound is disclosed in US Pat. No. 2,992,212 and JP-A-57-111307.
No. Regarding the catalyst system combining titanium trichloride and organic titanium compound not containing aluminum, a catalyst system combining a catalyst in which a titanium compound is supported on magnesium chloride and an organic titanium compound instead of titanium trichloride is a solid catalyst component. It has been reported that an α-olefin polymer having a high activity and a high stereoregularity per titanium in the steel can be obtained (for example, Soga et al., Makromol. Chem. Rapid Commun., Vol. 7, 719, 1986).
page). Furthermore, it has been found that a polymer having high activity and high stereoregularity can be obtained by polymerizing an α-olefin with a catalyst comprising a solid catalyst component comprising magnesium, titanium and halogen as essential components, an organic titanium compound and an aluminoxane. It has been proposed in 1-217012.

On the other hand, as an olefin polymerization catalyst, a metallocene compound having a group having a conjugated π electron, particularly cyclopentadiene or a derivative thereof as a ligand, and an alkylaluminoxane obtained by reacting a trialkylaluminum with water are used. Things are known. For example, JP-A-58-19309 discloses a method for polymerizing olefins using biscyclopentadienyl zirconium dichloride and methylaluminoxane as catalysts. JP-A-61-130314, JP-A-61-264010, JP-A-1-301704 and JP-A-2-41303 disclose a method for producing isotactic poly-α-olefin or syndiotactic poly-α-olefin and Polymerization catalysts for producing stereoregular poly-α-olefins are disclosed, but all of the disclosed catalyst systems use aluminoxane as a cocatalyst.

[0005] On the other hand, there has been conventionally studied a homogeneous Ziegler-Natta catalyst which does not use an aluminoxane.
Although this catalyst has low activity, it is already known that it has polymerization activity for olefins. It is believed that the active species of this catalyst is a cationic metallocene compound or an ion-pair metallocene complex.

[0006] Recently, it has been reported that an isolated cationic metallocene compound having cyclopentadiene or a derivative thereof as a ligand has polymerization activity for olefins alone, even in the absence of methylaluminoxane as a cocatalyst. Have been.

Further, Marks et al., Langmuir, 1988, Volume 4, 5
No. 1212-1214 reports that a catalyst supporting a dimethylzirconium complex having a cyclopentadienyl derivative as a ligand on alumina, which has been completely dehydrated by heat treatment at around 1000 ° C, exhibits ethylene polymerization activity. are doing. This catalyst system is also believed to be a cationic metallocene compound. However, in this method, a description relating to ethylene is found, but a description relating to α-olefin is not made.

[0008]

SUMMARY OF THE INVENTION A catalyst system comprising a catalyst in which a titanium compound is supported on magnesium chloride and an organic titanium compound has insufficient polymerization activity and can be commercialized without removing any catalyst residue. This is difficult, and it is desired to further improve the catalytic activity.

Further, since the organic titanium compound is unstable and easily decomposed, an organic zirconium compound, an organic hafnium,
It is desirable to use a more stable organic transition metal compound such as an organic vanadium compound. However, when these transition metals are used as a catalyst, the catalytic activity is reduced, and the stereoregularity is greatly reduced. Things were not favorable (eg Soga et al., Makromol. Chem., 1989
190, 31-35). The method according to the above-mentioned Japanese Patent Application Laid-Open No. 1-217012 has further improved the activity since it further uses aluminoxane to solve this problem. However, in these conventional solid Ziegler-Natta catalysts, the titanium component contained in the solid catalyst exhibits polymerization activity, and the organic titanium component is not considered as an active species. Although the activity per titanium component contained in was high, the activity per organic titanium component used in large amounts was very low.

The method disclosed in JP-A-58-19303 has a good activity per transition metal and a molecular weight distribution of about 2
This is an excellent method to obtain the polymer before and after. However, although the method using these aluminoxanes improves the polymerization activity, it requires the use of a large amount of expensive aluminoxanes, which has the problem of increasing the cost of the resulting polymer. In addition, there is a problem that it is difficult to remove aluminoxane from the produced polymer after polymerization.

On the other hand, the method of polymerizing olefins with a combination catalyst of a metallocene compound and an alkylaluminoxane disclosed in JP-A-58-19309 and the like is characterized by high polymerization activity per transition metal. However, the high polymerization activity per metallocene compound unit in these methods is due to the use of a large amount of expensive aluminoxane as a co-catalyst, thereby increasing the production cost of the polymer. It is very difficult to remove aluminoxane from the polymer, and there has been a problem that a large amount of catalyst residue remains in the polymer.

[0012]

Means for Solving the Problems The present inventors have intensively searched for a stable catalyst system capable of polymerizing an α-olefin with high activity without using an alkylaluminoxane while solving the above-mentioned problems, and conducted a study. Completed the invention. That is, the present invention provides a) a compound represented by the following general formula 3 or 4
A and B or A ′ and B ′ are the same or different monovalent or divalent unsaturated hydrocarbon residues, R is a divalent linear saturated hydrocarbon residue which may have a side chain, or M represents a residue in which part or all of the straight-chain carbon atoms are substituted with a silicon atom, a germanium atom, or a tin atom.
A metal atom selected from titanium, zirconium and hafnium , and X is a hydrocarbon residue or a halogen atom)
A transition metal compound represented by

[0013]

Embedded image

[0014]

Embedded image b) gold selected from aluminum, zinc and magnesium
Previously contacting an organometallic compound of the genus then, c) a polyolefin, which comprises polymerizing an olefin using a catalyst obtained by contacting the magnesium halide compound containing 1 to 20% by weight of water It is a manufacturing method.

In the present invention, examples of the transition metal compound having, as a ligand, a group having a conjugated π electron represented by the above general formula (3) or (4) include compounds described in the above-mentioned documents. The transition metal compound having a different structure may be a transition metal compound having a group having a conjugated π electron as a ligand.

In the above general formula (3) or (4),
Examples of the unsaturated hydrocarbon residue represented by A, B, A ′ or B ′ include a monocyclic or polycyclic group having 5 to 50 carbon atoms having a conjugated π electron. Petadienyl or its partial or total hydrogen substituted with a hydrocarbon residue having 1 to 10 carbon atoms (where the hydrocarbon residue has a structure in which the terminal is again bonded to the cyclopentadiene ring, Or a polycyclic aromatic hydrocarbon residue such as indenyl or fluorenyl, or part or all of the hydrogen thereof has 1 to 10 carbon atoms.
And the like.

As the divalent group represented by R, a methylene group represented by the following formula (5) or a part or all of carbon atoms of the methylene group is substituted by a silicon atom, a germanium atom, or a tin atom. Silylene group, germylene group,
Those having a stannylene group are exemplified.

[0018]

Embedded image _{- (R '2 C) n-} (R' 2 Si) m- (R '2 Ge) p- (R' 2 Sn) q- ( wherein R 'is hydrogen or C 1 -C And two R's may be the same or different, and n, m, p, and q are integers of 0 to 4 and represent an integer satisfying the following formula: 1 ≦ n + m + p + q ≦ 4 .)

X is a hydrocarbon residue having 1 to 10 carbon atoms or a halogen atom such as fluorine, chlorine, bromine or iodine.

As the organometallic compound used in the present invention, a compound of a metal selected from aluminum, zinc and magnesium is used. These organometallic compounds have residues such as halogen, oxygen, hydrogen, alkyl, alkoxy, and aryl as ligands, and these ligands may be the same or different, but at least One has a hydrocarbon residue. For example, carbon number 1-12
Alkyl metal compounds, alkyl metal halides, alkyl metal alkoxides, etc. in which 1 to n hydrocarbon residues are bonded. Among them, alkyl aluminum compounds are preferably used, for example, trimethyl aluminum,
Examples include triethylaluminum, triisopropylaluminum, tributylaluminum, dimethylaluminum chloride, diethylaluminum chloride, diisopropylaluminum chloride, diisopropylaluminum isopropoxide, ethylaluminum dichloride, ethylaluminum diisopropoxide and the like.

The use ratio of the organometallic compound to the above transition metal compound is from 1 to 100,000 times, usually from 1 to 5000 times.
It is molar times.

The magnesium halide compound used in the present invention includes magnesium chloride, magnesium bromide, magnesium iodide, magnesium chlorobromide, magnesium chloroiodide, magnesium bromoiodide, magnesium hydride, magnesium chloride hydroxide. , Magnesium bromide hydroxide, magnesium chloride alkoxide, magnesium bromide alkoxide, and other magnesium compounds having at least one halogen atom.

Here, what is important in the present invention is that the content of water contained in these magnesium halide compounds is 1%.
It is necessary to use a magnesium halide compound containing from 20% by weight to 20% by weight of water. When a magnesium halide compound having a water content of 1% by weight or less or 20% by weight or more is used, the activity becomes low. Although this is unknown at present, it is considered that the magnesium halide compound contains a small amount of water, so that its acidity changes and the transition metal compound is easily activated. On the other hand, a substance containing a large amount of water is not preferable because decomposition of a transition metal compound or an alkylaluminum compound occurs.

Such hydrated magnesium halide compounds are usually commercially available magnesium halide compounds containing anhydrous salts or water of crystallization. These may be mixed in an appropriate ratio or mixed with the anhydrous salts. It can be obtained by adding an appropriate amount of water. In use, it is preferable to use those whose surface area is increased by a method such as further pulverizing these magnesium halide compounds or dissolving them once and precipitating them again.

The use ratio of the magnesium halide compound to the above transition metal compound is 0.1 to 100,000 times, usually 0.5 to 10,000 times.

The solvent used in the preparation, polymerization or treatment of the catalyst using the catalyst component in the present invention includes, for example, saturated hydrocarbons such as propane, pentane, hexane, heptane, octane, nonane, decane, cyclopentane and cyclohexane. Compounds, aromatic hydrocarbon compounds such as benzene, toluene and xylene, and halogenated hydrocarbon compounds such as methylene chloride and chlorobenzene can also be used. In addition, ethers, nitriles, ester compounds, and the like can be used as long as the solvent itself does not bind to the generated transition metal cation compound or strongly coordinate to inactivate the polymerization activity.

The polymerization conditions of the olefin using the catalyst component are not particularly limited, and a solvent polymerization method using an inert medium, a bulk polymerization method using substantially no inert medium, and a gas phase polymerization method can be used.

Examples of the olefin used for the polymerization include olefins having 2 to 25 carbon atoms. Specific examples include ethylene, propylene, butene-1, pentene-1, and hexene.
1, heptene-1, octene-1, nonene-1, decene-1, undecene-1, dodecene-1, tridecene-1, tetradecene
-1, pentadecene-1, hexadecene-1, octadecene-1
Other than linear α-olefins such as 3-methylbutene-1, 4-
Branched α such as methylpentene-1,4,4-dimethylpentene-1
-Olefins and cyclic olefins such as cyclopentene, cyclooctene, norbornene and the like are exemplified, and these can be used for homopolymerization or mutual copolymerization, and if necessary, copolymerization with a diene or the like.

As the polymerization temperature and the polymerization pressure, general conditions used in a known method are used. The polymerization temperature is -20 to 150 ° C., and the polymerization pressure is normal pressure to 50 kg / cm ² .

[0030]

The present invention will be further described with reference to examples.

Example 1 A vibrating mill equipped with two 1-liter grinding pots containing 300 steel balls having a diameter of 12 mm was prepared. Under a nitrogen atmosphere, 16 g of anhydrous magnesium chloride (manufactured by Toho Titanium, surface area: 14 m ² / g), 4 g of magnesium chloride hexahydrate, and 4 ml of toluene were added to the pot and ground for 76 hours. From the measurement of the water content of the ground material, it was found that the ground material contained 8.8% by weight of water. The surface area of the obtained pulverized product was 90 m ² / g.

The isopropylcyclopentadienyl-1-fluorene synthesized according to a conventional method is lithium-treated, reacted with zirconium tetrachloride and recrystallized to obtain 40 mg of isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dichloride. It was dissolved in 50 ml of toluene, and 0.86 g of triethylaluminum was added. Further, 2 g of the above-mentioned ground magnesium compound was added to obtain a catalyst component.

Next, the above catalyst component was charged into a 5-liter autoclave which had been thoroughly dried and purged with nitrogen under a nitrogen stream, and 1.5 kg of liquid propylene was added thereto.
The polymerization was continued for 2 hours by heating to ° C. The unreacted propylene was purged and the contents were taken out and dried at 60 ° C. and 70 mmHg for 8 hours to obtain 158 g of white powdery polypropylene (this was
Equivalent to 18.7 kg polypropylene / g zirconium. ).

According to ¹³ C-NMR, the syndiotactic pentad fraction was 0.80, and the intrinsic viscosity (hereinafter referred to as η) measured at 135 ° C. in tetralin solution was 0.50, 1,2,4-trichlorobenzene. The ratio of the weight average molecular weight to the number average molecular weight (hereinafter referred to as MW / MN) measured in 2.6 was 2.6.

Example 2 Trimethylaluminum instead of triethylaluminum
The polymerization was carried out in the same manner as in Example 1 except that 0.54 g of the system was used.
As a result, 227.3 g of a white powdery polypropylene was obtained.
(This is equivalent to 32.8kg polypropylene / g zirconium)
Hit. ). Also ¹³According to C-NMR, syndiotactic
The pentad fraction is 0.79, η is 0.47, MW / MN is 2.5
Met.

Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 without using triethylaluminum, but no polymer was obtained.

Comparative Example 2 Example 1 was repeated except that 20 g of anhydrous magnesium chloride (manufactured by Toho Titanium, surface area: 14 m ² / g) was used in place of 16 g of anhydrous magnesium chloride and 4 g of hexahydrate of magnesium chloride. A pulverized magnesium compound was synthesized in the same manner as described above. 0.03wt% for this pulverized material from the moisture measurement of the pulverized material
The water contained. The surface area of the obtained pulverized material is
It was 103.9 m ² / g.

Propylene was polymerized in the same manner as in Example 1 except that this ground magnesium compound was used, to obtain 50 g of a polymer (this corresponds to 5.9 kg of polypropylene / g of zirconium). According to ¹³ C-NMR, the syndiotactic pentad fraction was 0.79, and η was
0.43 and MW / MN were 2.5.

Example 3 2 ml of ion-exchanged water degassed in 18 g of anhydrous magnesium chloride (manufactured by Toho Titanium, surface area: 14 m ² / g) instead of 16 g of anhydrous magnesium chloride and 4 g of hexahydrate of magnesium chloride in Example 1 A ground magnesium compound was synthesized in the same manner as in Example 1 except for using. From the measurement of the water content of the ground product, it was found that the ground product contained 8.4% by weight of water. The surface area of the obtained pulverized product was 160 m ² / g.

Using this ground magnesium compound, propylene was polymerized in the same manner as in Example 1 except that 1.5 g of triisobutylaluminum was used instead of triethylaluminum, and 197 g of a polymer was obtained.
Equivalent to 3.3 kg polypropylene / g zirconium. ). According to ¹³ C-NMR, the syndiotactic pentad fraction was 0.81, η was 0.58, and MW / MN was 2.5.

[0041]

According to the present invention, a polyolefin can be obtained with high activity per catalyst by using an inexpensive catalyst, which is extremely valuable industrially.

[Brief description of the drawings]

FIG. 1 is a flowchart for helping an understanding of the present invention.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-709 (JP, A) JP-A-2-173104 (JP, A) JP-A-60-67511 (JP, A) JP-A-4- 96908 (JP, A) JP-B-53-40632 (JP, B1) JP-T2-503687 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 4/60-4 / 70

Claims (1)

(57) [Claims] (1) a) a compound represented by the following general formula (1) or (2):
A and B or A ′ and B ′ are the same or different monovalent or divalent unsaturated hydrocarbon residues, R is a divalent linear saturated hydrocarbon residue which may have a side chain, or M represents a residue in which part or all of the straight-chain carbon atoms are substituted with a silicon atom, a germanium atom, or a tin atom.
A metal atom selected from titanium, zirconium and hafnium , and X is a hydrocarbon residue or a halogen atom)
A transition metal compound represented by the following formula: Embedded image b) gold selected from aluminum, zinc and magnesium
Previously contacting an organometallic compound of the genus then, c) a polyolefin, which comprises polymerizing an olefin using a catalyst obtained by contacting the magnesium halide compound containing 1 to 20% by weight of water Production method.