JPH05239140A - Catalyst for olefin polymerization and production of polyolefin using the catalyst - Google Patents

Abstract

PURPOSE:To provide the subject catalyst composed of a neutral derivative of metallocene, tropylium borate and an alkylaluminum and capable of reducing the amount of alkylaluminum and dispensing with the use of expensive methyl alumoxane. CONSTITUTION:The objective catalyst is composed of (A) a neutral derivative of a metallocene of formula I [Cp<1> and Cp<2> are (substituted)cyclopentadienyl; M<1> is metal of the group III to VI; R<1> is alkyl; R<2> is H, halogen, etc.; (p) is 0-3], (B) a tropylium borate of formula II (C7H7 is tropylium ion; R<3> to R<7> are H, F, etc.; B is boron having atomic valence of 3) and (C) an alkylaluminum of the formula AlR<8>3 (R<8> is halogen, alkyl, etc., provided that at least one of R<8> is alkyl). The component A is preferably ethylenebis(indenyl) zirconium dimethyl and the component C is preferably trimethylaluminum, etc. The component B is e.g. tropylium tetrakis(phenyl)borate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an olefin polymerization catalyst and a method for producing a polyolefin using this catalyst.

[0002]

2. Description of the Related Art A Ziegler-Natta catalyst is basically used for the polymerization of olefins. One of the Ziegler-Natta catalysts is a Group IV metallocene compound catalyzed by methylalumoxane. This catalyst has the advantage of high catalytic activity and the ability to produce stereoregular polyolefins. However, the main drawback that has so far prevented the catalyst from being used industrially on a large scale is the large amount of expensive methylalumoxane.

On the other hand, as shown in the following equation,
It is known that Ziegler-Natta catalysts for olefin polymerization can be prepared by combining a Group V metallocene compound with an ionic compound.

[0004]

[Chemical 7] [In the formula, Cp ^* is a pentamethylcyclopentadienyl group, M ² is a Group IV metal, R ⁹ is an alkyl group, L is a ligand, [C] is a cation, and [A] is an anion. The compound obtained by this reaction is a metallocene cation that acts as a catalyst, and the cation [C] of the ionic compound reacts with the metallocene ligand to form an ion pair. Further, the anion [A] is not coordinated or is loosely coordinated with the cation metallocene.

The following reactions have been proposed as the above reaction system.

That is, "Cationic dicyclopentadienyl zirconium (IV) alkyl complex", M.A. Bochmann, L.A. M. Wilson (Wi
lson), Journal of Chemical Society Communication (J. Chem. So.
c. Commun. ), 1610-1611 (198
5): “Cationic alkylbis (cyclopentadienyl) titanium complex”, M.A. Boffman, L.A. Wilson, Organometallic
ics), 6, 2556-2563 (1987): "Intercalation reaction in cationic alkylbis (cyclopentadienyl) titanium complex", M. et al. Boffman, L.A. Wilson, Organo Metallics, 7, 1147-1154
(1987) one-electron oxidation method.

The protonation process exemplified by European Patent No. 277,004. In this method, the bis (cyclopentadienyl) metal compound is a ionic compound having a cation that irreversibly reacts with the ligand of the metal compound and an anion having a plurality of lipophilic groups around the metal or metal ion. Combined, for example the following reactions are illustrated.

[0008]

[Chemical 8] [In the formula, Cp is a cyclopentadienyl group, Me is a methyl group, n-Bu is a normal butyl group, and C ₆ F ₅ is a pentafluorophenyl group. The by-products of the protonation process are Lewis bases (amines), some of which can coordinate cations and interfere with catalytic activity.

"Multiple Metal-Carbon Bonds", R.S. R. Schrock, P. R. Sharp
p), Journal of American Chemical Society (J. Am. Chem. Soc.),
100 (8), 2389-2399 (1978) and the carbonium ion chemical method exemplified in JP-A-3-207703.

However, these methods have a problem that the cation is poisoned by the basic impurities found in the olefin and the solvent, and the polymerization activity is hindered.

Further, JP-A-3-207704 describes the use of aluminum alkyl as a scavenger of a poison that reduces the activity of the metallocene catalyst. However, this method uses an excessive amount of aluminum alkyl and thus requires a great deal of cost to remove the residual catalyst components.

[0012]

DISCLOSURE OF THE INVENTION The present invention provides an improved method for producing a catalyst for the above-mentioned conventional olefin polymerization, and its object is to provide a scavenger of a poison that reduces the activity of a metallocene catalyst. Reducing the amount of aluminum alkyl used and eliminating the use of methylalumoxane as a cocatalyst in olefin polymerization.

[0013]

Means for Solving the Problems In order to solve the above problems, the present inventors have earnestly studied in order to develop a method for producing a catalyst system exhibiting high activity without using a large amount of aluminum alkyl, and as a result, the present invention was obtained. Has been completed. That is, the present invention comprises a) a neutral derivative of metallocene, b) tropylium borate and c) aluminum alkyl, wherein a) the neutral derivative of metallocene has the general formula

[0014]

[Chemical 9] [Wherein, Cp ¹ and Cp ² are each independently a cyclopentadienyl or substituted cyclopentadienyl group, M ¹ is a Group III, IV, V or VI metal, and R ¹ is an alkyl group And R ² is a hydrogen, halogen, amido or alkyl group, each R ² may be the same or different, and p is 0-3. ], B) tropylium borate is represented by the general formula

[0015]

[Chemical 10] [In the formula, C ⁷ H ⁷ is a tropylium ion (cycloheptatrienyl cation), R ^{3 to} R ⁷ are each independently hydrogen, fluorine or a trifluoromethyl group, and B is boron in the valence state 3. ], C) aluminum alkyl has the general formula

[0016]

[Chemical 11] Wherein R ⁸ is a halogen, oxygen, hydrogen, alkyl, alkoxy or aryl group, each R ⁸ may be the same or different, and at least one R ⁸ is an alkyl group. ] It is related with the polymerization catalyst system shown by these, and the manufacturing method of polyolefin using the same.

The contents of the present invention will be described in detail below.

The olefin polymerization catalyst of the present invention is prepared by mixing b) tropylium borate and a) a neutral derivative of metallocene, and c) a mixture of aluminum alkyl and olefin according to the following reaction formula. Done.

[0019]

[Chemical 12] [Wherein, Cp ¹ and Cp ² are each independently a cyclopentadienyl or substituted cyclopentadienyl group, M ¹ is a Group III, IV, V or VI metal, and R ¹ is an alkyl group R ² is hydrogen, halogen, amido or an alkyl group, each R ² may be the same or different, and p is 0 to 3, C ₇ H ₇ is a tropylium ion (cycloheptatrienyl). Cation) and R ^{3 to} R
⁷ is each independently a hydrogen, fluorine or trifluoromethyl group, and B is boron in the valence state 3. In the above reaction, each compound is placed in a solvent that does not or only loosely coordinates with the metallocene cation. Although such a solvent is not particularly limited, toluene or methylene chloride is exemplified. The two compounds are dissolved in a solvent and 1 mol of metallocene: tropylium borate 0.1
Mix at a molar ratio in the range of -100 mol. A suitable mol ratio is 1 mol of metallocene: tropylium borate.
1 to 10 mol. After mixing, the mixture is added to the olefin under conditions which effect polymerization.

As used herein, b) tropylium volatilizer
Examples of tropylium tetrakis (phenyl) borate, tropylium tetrakis (p-tolyl)
Borate, tropylium tetrakis (m-tolyl) borate, tropylium tetrakis (2,4-dimethylphenyl) borate, tropylium tetrakis (3,5-dimethylphenyl) borate, tropylium tetrakis ( Pentafluorophenyl) borate, tropylium tetrakis (3-trifluoromethylphenyl) borate
G, tropylium tetrakis (4-trifluoromethylphenyl) borate, tropylium tetrakis (3,5
-Di-trifluoromethylphenyl) borate, tropylium tetrakis (2,3,5,6-tetrafluoro-
4-trifluoromethylphenyl) borate and the like can be mentioned.

Further, tropylium borate is produced, for example, by the following reaction formula.

[0022]

[Chemical 13] [In the formula, C ₇ H ₇ is a tropylium ion (cycloheptatrienyl cation), X is a halogen, and R ^{3 to} R ⁷ are each independently hydrogen, fluorine or a trifluoromethyl group, B
Is boron in valence state 3. That is, it is synthesized by dissolving tropylium halide and lithium salt of borate in a solvent and mixing them. The solvent in this case is not particularly limited, but water, hexane, methylene chloride or the like is exemplified.

Specific examples of the a) neutral derivative of metallocene used in the present invention include bis (cyclopentadienyl) titanium dimethyl, bis (pentamethylcyclopentadienyl) titanium dimethyl and ethylenebis (tetrahydroindenyl). Titanium dimethyl, ethylene bis (indenyl) titanium dimethyl, isopropylidene (cyclopentadienyl-1-fluorenyl)
Titanium dimethyl, dimethylsilylbis (methylcyclopentadienyl) titanium dimethyl, dimethylsilylbis (2,4-dimethylcyclopentadienyl) titanium dimethyl, bis (cyclopentadienyl) zirconium dimethyl, bis (pentamethylcyclopentadiene (Enyl) zirconium dimethyl, ethylene bis (tetrahydroindenyl) zirconium dimethyl, ethylene bis (indenyl) zirconium dimethyl, isopropylidene (cyclopentadienyl-1-fluorenyl) zirconium dimethyl, dimethylsilylbis (methylcyclopentadienyl) zirconium dimethyl , Dimethylsilylbis (2,4-dimethylcyclopentadienyl) zirconium dimethyl, bis (cyclopentadienyl) hafnium dimethyl, bi (Pentamethylcyclopentadienyl) hafnium dimethyl, ethylenebis (tetrahydroindenyl) hafnium dimethyl, ethylenebis (indenyl) hafnium dimethyl, isopropylidene (cyclopentadienyl-1-fluorenyl) hafnium dimethyl, dimethylsilylbis (methylcyclo) Pentadienyl) hafnium dimethyl, dimethylsilylbis (2,4
-Dimethylcyclopentadienyl) hafnium dimethyl and the like, most preferably ethylenebis (indenyl) zirconium dimethyl.

Specific examples of c) aluminum alkyl include trimethyl aluminum, triethyl aluminum, triisopropyl aluminum, tri-n-propyl aluminum, triisobutyl aluminum, tri-n-butyl aluminum, tri-n-hexyl aluminum and tri. -N-octyl aluminum, dimethyl aluminum chloride, diethyl aluminum chloride, diisopropyl aluminum chloride, di-n-
Propyl aluminum chloride, diisobutyl aluminum chloride, di-n-butyl aluminum chloride, dimethyl aluminum ethoxide, diethyl aluminum ethoxide, diisopropyl aluminum ethoxide, di-n-propyl aluminum ethoxide, diisobutyl aluminum ethoxide, di-n
-Butyl aluminum ethoxide, dimethyl aluminum hydride, diethyl aluminum hydride, diisopropyl aluminum hydride, di-n
-Propyl aluminum hydride, diisobutyl aluminum hydride, di-n-butyl aluminum hydride and the like can be mentioned. Preferred are trimethyl aluminum, triethyl aluminum and triisobutyl aluminum. A suitable concentration of aluminum alkyl is 10 ⁻⁵ to 1 relative to olefin.
0, which is the ^-3 mol / l.

The olefin may be any of olefins, and specifically, ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-
It is an α-olefin such as octene or 1-decene, and a mixed component of two or more kinds thereof can be subjected to polymerization.
Copolymerization of the above α-olefins with ethylene is also possible. Furthermore, butadiene, 1,4-hexadiene, 1,
Conjugated and non-conjugated dienes such as 4-pentadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, or like styrene, cyclopropene, cyclobutene, cyclohexene, norbornene, dicyclopentadiene, etc. Copolymerization with various cyclic olefins is also effective.

The olefin polymerization is carried out by means known in the art for the polymerization of olefins with metallocenes, for example by bulk, slurry or gas phase polymerization. The polymerization temperature is in the range of -80 to 150 ° C, preferably 25 to 80 ° C.

[0027]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Triethylaluminum (TEAl) 0.66 mmol
Was dissolved in 5 ml of toluene and added to a 2 l autoclave reactor. The temperature of the reactor was set to 40 ° C. and 1.4 l of propylene was inserted into the reactor. 1200r mixture
Stirred at pm for 10 minutes.

15 μmol of tropylium tetrakis (pentafluorophenyl) borate was dissolved in 10 ml of toluene. Separately, 5 μmol of ethylenebis (indenyl) zirconium dimethyl was dissolved in 10 ml of toluene. The two mixtures were stirred together at room temperature for 5 minutes.

The catalyst mixture was inserted into the reactor under nitrogen pressure. The reactor temperature remained at 40 ° C. and the reactor contents were stirred for 60 minutes. At the end of the polymerization, the reactor was cooled and unreacted propylene was discharged from the reactor.

The reaction product was dried under vacuum at about 60 ° C. for 6 hours. As a result, 300 g of polymer was obtained.

Example 2 0.12 mmol of triethylaluminum (TEAl)
The method of Example 1 was followed except that as a result,
190 g of polymer were obtained.

Comparative Example 1 The method of Example 2 was followed except that 15 μmol of dimethylanilinium tetrakis (pentafluorophenyl) borate was used instead of tropylium tetrakis (pentafluorophenyl) borate. As a result, 80
g of polymer was obtained.

[0034]

As described above, according to the catalyst of the present invention and the olefin polymerization method using the same, the amount of aluminum alkyl used can be reduced and the use of expensive methylalumoxane can be eliminated. Polymerization can be carried out.

Claims (2)

[Claims] 1. A neutral derivative of a metallocene, a) a tropylium borate and c) an aluminum alkyl, wherein the neutral derivative of a) a metallocene has the general formula: [Wherein, Cp ¹ and Cp ² are each independently a cyclopentadienyl or substituted cyclopentadienyl group, M ¹ is a Group III, IV, V or VI metal, and R ¹ is an alkyl group And R ² is a hydrogen, halogen, amido or alkyl group, each R ² may be the same or different, and p is 0-3. ], B) tropylium borate is represented by the general formula: [In the formula, C ₇ H ₇ is a tropylium ion (cycloheptatrienyl cation), R ^{3 to} R ⁷ are each independently hydrogen, fluorine or a trifluoromethyl group, and B is boron in the valence state 3. ], C) aluminum alkyl has the general formula: Wherein R ⁸ is a halogen, oxygen, hydrogen, alkyl, alkoxy or aryl group, each R ⁸ may be the same or different, and at least one R ⁸ is an alkyl group. ] The catalyst system for olefin polymerization shown by these. 2. A step of d) mixing aluminum alkyl with an olefin, e) a step of mixing the neutral derivative of metallocene with tropylium borate, and f) a neutral derivative of the metallocene obtained by the above step e) and tropylium borate. And a mixture of the aluminum alkyl obtained in step d) above and a mixture of olefins, wherein the neutral derivative of the metallocene is represented by the general formula: [Wherein, Cp ¹ and Cp ² are each independently a cyclopentadienyl or substituted cyclopentadienyl group, M ¹ is a Group III, IV, V or VI metal, and R ¹ is an alkyl group And R ² is a hydrogen, halogen, amido or alkyl group, each R ² may be the same or different, and p is 0-3. ], The tropylium borate is represented by the general formula: [In the formula, C ₇ H ₇ is a tropylium ion (cycloheptatrienyl cation), R ^{3 to} R ⁷ are each independently hydrogen, fluorine or a trifluoromethyl group, and B is boron in the valence state 3. ] And aluminum alkyl has the general formula: Wherein R ⁸ is a halogen, oxygen, hydrogen, alkyl, alkoxy or aryl group, each R ⁸ may be the same or different, and at least one R ⁸ is an alkyl group. ] The manufacturing method of the polyolefin shown by these.