JPH072918A - Metallocene compound solution and method for its storage - Google Patents

Abstract

PURPOSE:To obtain a metallocene compd. soln. storable for a long term by mixing a specific transition-metal metallocene compd. with an organoaluminum compd. in a hydrocabon solvent. CONSTITUTION:A metallocene compd. soln. is obtd. by mixing a transition-metal metallocene compd. of formula I or II with an organoaluminum compd. in a hydrocabon solvnt. In the formulas, A and b are each an unsatd. hydrocarbon group cordinalted with the central atom provided they may be the same or different from each other, and so are A' and B' ; R is an optioanally branched divalent linear hydrocarbon group carbon atoms of which may be substd. by silicon, germanium, or tin atoms; X is a 1-200C hydrocarbon group; and M is a metal selected from metals of Groups 4 and 5 of the Periodic Table. The concn. of the metallocene compd. in the soln. is usually 1X10<-8>-1mol/l, pref. 1X10<-7>-0.1mol/l.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solution of a metallocene compound, and more particularly to a metallocene compound which can be stored for a long period of time and a storage method thereof.

[0002]

BACKGROUND OF THE INVENTION As a polymerization catalyst for olefins, a combination of a metallocene compound having a group having a conjugated π electron, particularly cyclopentadiene and its derivative as a ligand, and an alkylaluminoxane obtained by the reaction of trialkylaluminum and water. It has been known. For example, JP-A-58-19309 discloses a method for polymerizing biscyclopentadienyl zirconium dichloride and olefin using methylaluminoxane as a catalyst. In addition, JP-A-61-130
314, JP 61-264010, JP 1-301704 and JP 2-4
1303 discloses a method for producing isotactic poly-α-olefins or syndiotactic poly-α-olefins and a polymerization catalyst for producing these stereoregular poly-α-olefins. All of the above catalyst systems use aluminoxane as a cocatalyst.

On the other hand, research on homogeneous Ziegler-Natta catalysts that do not use aluminoxane has been conducted,
Although this catalyst has low activity, it is already known that it has polymerization activity for olefins. It is considered that the active species of this catalyst is a cationic metallocene compound or an ion pair type metallocene complex. Recently, an isolated cationic metallocene compound having cyclopentadiene or a derivative thereof as a ligand can be obtained without coexistence of methylaluminoxane as a cocatalyst.
It has been reported to have polymerization activity for olefins alone.

For example, RFJORDAN, etc. are J. Am. Chem. Soc.,
1986, Vol. 108, page 7410-7411, zirconium cation complex having tetraphenylborane as an anion and two cyclopentadienyl groups and a methyl group as ligands using a donor such as tetrahydrofuran as a ligand. It is reported that the isolated complex has an ethylene polymerization activity in methylene chloride.

Turner et al., J. Am. Chem. Soc., 1989
Volume 111, pages 2728-2729 and special table 1-501950, special table 1-5020
From a metal compound having a cyclopentadienyl group having at least one substituent capable of reacting with a proton at 36 or a derivative thereof as a ligand, and a compound providing a stable anion having a cation capable of giving a proton. It is reported that the formed ion-pair type metallocene complex has olefin polymerization activity.

Further, Zambelli et al., Macromolecules, 1989.
Vol. 22, pp. 2186-2189, pp. 2186-2189, shows that isotactic polypropylene can be obtained by polymerizing propylene with a catalyst that combines a zirconium compound having a cyclopentadienyl group derivative as a ligand and trimethylaluminum and fluorodimethylaluminum. It has been reported, and in this case also, the active species is considered to be an ion pair type metallocene compound.

[0007]

[Problems to be Solved by the Invention] Polymerization method using a metallocene compound and aluminoxane according to the above-mentioned JP-A-58-19309, a method of polymerizing using a cationic metallocene complex of RFJORDAN et al., TURNER et al., And further trimethyl of Zambelli et al. Polymerization methods for α-olefins that use metallocene compounds as catalysts, such as those that use aluminum, dimethylaluminum fluoride and zirconium complex, have high catalytic activity and have a narrow molecular weight distribution of about 2 and composition distribution in copolymerization. It is a catalyst that has characteristics such that narrow ones can be obtained.

However, the metallocene compound has a low solubility in a hydrocarbon solvent, and in a solution in which the metallocene compound is dissolved in a hydrocarbon solvent, it is easily decomposed by a very small amount of water, impurities such as air, or light, and thus the solution. Difficult to save as. Therefore, when used as a catalyst as described above, the solution of the metallocene compound once dissolved in a hydrocarbon solvent is stored, the polymerization activity will almost disappear, so a metallocene solution is prepared every time the polymerization is performed. Had to do.

[0009]

[Means for Solving the Problems] The present inventors have completed the present invention by solving the above problems and earnestly studying a metallocene solution which shows no decrease in activity even after being stored for a long period of time.

That is, the present invention comprises: a) a transition metal metallocene compound represented by the following chemical formula 5 or 6

[0011]

[Chemical 5]

[0012]

[Chemical 6] (In the formula, A and B or A ′ and B ′ are the same or different from each other, and an unsaturated hydrocarbon residue coordinated to a central atom, and R is a divalent straight chain which may have a side chain. A hydrocarbon residue or a residue in which a linear carbon atom thereof is substituted with a silicon atom, a germanium atom or a tin atom, is represented by X
Represents a hydrocarbon residue having 1 to 20 carbon atoms, and M represents a metal atom selected from Groups 4 and 5 of the Periodic Table. ) B) An organoaluminum compound and c) a metallocene compound solution prepared by mixing in a hydrocarbon solvent. The present invention also includes: a) a transition metal metallocene compound represented by the following general formula (7) or (8)

[0013]

[Chemical 7]

[0014]

[Chemical 8] (In the formula, A and B or A ′ and B ′ are the same or different from each other, and an unsaturated hydrocarbon residue coordinated to a central atom, and R is a divalent straight chain which may have a side chain. A hydrocarbon residue or a residue in which a linear carbon atom thereof is substituted with a silicon atom, a germanium atom or a tin atom, is represented by X
Represents a hydrocarbon residue having 1 to 20 carbon atoms, and M represents a metal atom selected from Groups 4 and 5 of the Periodic Table. ) B) An organoaluminum compound and c) are dissolved and stored in a hydrocarbon solvent and stored.

In the present invention, examples of the transition metal compound represented by the general formula 7 or 8 include compounds generally known as metallocene compounds. These compounds are transition metal compounds having a group having a conjugated π electron as a ligand, and in the formula, A and B or A ′ and B ′ are the same or different from each other and are monovalent or divalent unsaturated hydrocarbon residues. R is a divalent linear hydrocarbon residue which may have a side chain, or a residue in which some or all of the carbon atoms of the linear chain thereof are substituted with silicon atoms, germanium atoms or tin atoms. Group, X represents a hydrocarbon residue having 1 to 20 carbon atoms, and M represents a metal atom selected from Group 4 and Group 5 of the periodic table.

The unsaturated hydrocarbon residue represented by A, B, A'or B'is a monocyclic ring having 5 to 50 carbon atoms,
Alternatively, a group having a polycyclic conjugated π electron can be exemplified, and specifically, a group in which cyclopetadienyl or a part or all of hydrogen thereof is substituted with a hydrocarbon residue having 1 to 10 carbon atoms (here, carbonized) The hydrogen residue may have a structure in which its end is again bound to the cyclopentadiene ring).
Alternatively, examples thereof include polycyclic aromatic hydrocarbon residues such as indenyl and fluorenyl, or those in which a part or all of the hydrogen thereof is substituted with a hydrocarbon residue having 1 to 10 carbon atoms.

As the divalent group represented by R, a methylene group represented by the following general formula 9 or a part or all of the carbon atoms of the methylene group are silicon atoms, germanium atoms,
Alternatively, those having a silylene group substituted with a tin atom, a germylene group or 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 2 to R 20 may be the same or different, and n, m, p and q are integers from 0 to 4 and satisfy the above formula.).

Examples of X include an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, an aryl group such as a phenyl group, a benzyl group and a cyclopentadienyl group.

In the present invention, the general formula 7 or 8
The transition metal metallocene compound represented by is contacted with the organoaluminum compound in a hydrocarbon solvent to synthesize a uniform solution. Examples of the organoaluminum compound used here include a halogen atom, an oxygen atom, a hydrogen atom, an alkyl group,
Residues such as alkoxy and aryl groups are coordinated,
When there are a plurality of ligands, those ligands may be the same or different, and at least one of them is an alkyl group. For example, an alkylaluminum compound in which 1 to 3 alkyl residues having 1 to 12 carbon atoms are bonded, an alkylaluminum halide, an alkylaluminum hydride, an alkylaluminum alkoxide and the like can be used. For example, trimethyl aluminum, triethyl aluminum, tripropyl aluminum, triisopropyl aluminum,
Tributyl aluminum, trihexyl aluminum,
Trioctyl aluminum, dimethyl aluminum chloride, diethyl aluminum chloride, diisopropyl aluminum chloride, diisopropyl aluminum isopropoxide, ethyl aluminum dichloride, diisobutyl aluminum hydride, ethyl aluminum diisopropoxide, isobutyl aluminum ethoxide, and the like, and these aluminum compounds. Of these, trialkylaluminum compounds are particularly preferable.

The method for producing the above transition metal metallocene compound solution can be easily obtained by bringing the transition metal metallocene compound and the organoaluminum compound into contact with each other in a hydrocarbon solvent. The method of contacting is arbitrary, and in short, these three compounds may be mixed. In this case, even if the transition metal metallocene compound solution is not completely dissolved in the hydrocarbon solvent, a uniform metallocene compound solution can be obtained by further adding the organoaluminum compound to the hydrocarbon solvent.

In the present invention, since the metallocene compound and the organoaluminum compound react in a hydrocarbon solvent, it seems that the metallocene compound is solubilized in the hydrocarbon solvent. Moreover, even when the metallocene compound solution thus obtained is stored for a long period of time, the metallocene compound is decomposed to form an insoluble matter, and the activity decreases even when used as a polymerization catalyst for olefins. It can prevent things from becoming active. The temperature at which these are brought into contact with each other is not particularly limited, but it is usually preferable to carry out at a temperature of −20 to 100 ° C. The temperature at which these are stored is not particularly limited, but it is preferably stored at a temperature of −20 to 100 ° C. as well.

The mixing ratio of the organoaluminum compound to the transition metal metallocene compound in the solution is usually 1 to 1000 times the amount of aluminum to the transition metal atom. Of course, there is no problem even if an excess amount of the organoaluminum compound is used, but even if it is used in an excessively large amount, the activity is not further improved and it is uneconomical.

Examples of the hydrocarbon solvent used in the present invention include benzene, in addition to aliphatic hydrocarbon compounds such as propane, butane, pentane, hexane, heptane, octane, nonane, decane, hexadecane, cyclopentane and cyclohexane. Aromatic hydrocarbon compounds such as toluene, xylene and ethylbenzene, and ether compounds or ester compounds such as diethyl ether and tetrahydrofuran can also be used. Halogenated hydrocarbon compounds such as methylene chloride can also be used as long as they do not react with the organoaluminum compound used.

The concentration of the metallocene compound in the metallocene compound solution of the present invention is not particularly limited, but it is usually 10 ^-8 to 1 mol / liter, preferably 10 ^{-7 to} 0.1 mol / liter. .

The metallocene compound solution of the present invention is used for olefin polymerization in combination with a conventionally known organometallic compound for olefin polymerization as described above, or in combination with a compound capable of reacting with a metallocene compound to form an ionic compound. To be As the organometallic compound for olefin polymerization, the following general formula 10 or 11

[0027]

[Chemical 10]

[0028]

[Chemical 11] (In the formula, R is an alkyl group having 1 to 6 carbon atoms and n is an integer of 1 or more.), Which are trialkylaluminum as raw materials.
It is produced by various methods, such as by reacting with ~ 3 mole times water. Examples of the trialkylaluminum include trimethylaluminum, triethylaluminum, tripropylaluminum, tri-n-butylaluminum, triisobutylaluminum, trihexylaluminum or a mixture thereof.

Examples of the compound that reacts with the metallocene compound to form an ionic compound include an ionic compound formed from an ion pair of a cation and an anion, and an electrophilic compound. These compounds are generally known as Lewis acid compounds, have appropriate Lewis acidity, and have the property of reacting with a neutral metallocene compound used as a catalyst to convert to an ionic compound. If necessary, it reacts with the transition metal compound represented by the above general formula 7 or 8 to transfer the group represented by X in the formula to the Lewis acid compound as an electron pair to form a transition metal cation compound. It does not inactivate the polymerization activity by recombining with the Lewis acid itself or the transition metal cation compound produced by the anion forming an ion pair, or strongly coordinating.

Examples of the cation of the ionic compound include:
Examples thereof include carbonium cation, tropylium cation, oxonium cation, sulfonium cation, phosphonium cation, and ammonium cation.

Examples of the anion of the ionic compound include:
Metal oxides such as organic boron compound anions, organic aluminum compound anions, organic phosphorus compound anions, organic arsenic compound anions, and organic antimony compound anions. Electrophilic compounds are known as metal halides and solid acids. Etc.

The olefins used for the polymerization include ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1,
Undecene-1, dodecene-1, tridecene-1, tetradecene-1, pentadecene-1, hexadecene-1, octadecene
In addition to linear α-olefins such as -1, 3-methylbutene-1,
Examples are branched α-olefins such as 4-methylpentene-1,4,4-dimethylpentene-1, and these olefins may be used alone or as a mixture with each other or with a small amount of a polyene such as a diene. It can be polymerized.

There are no particular restrictions on the polymerization conditions using such an olefin polymerization catalyst, and a solvent polymerization method using an inert medium, a bulk polymerization method in which substantially no inert medium is present, or a gas phase polymerization method is also used. The polymerization temperature is -10
0 ~ 200 ℃, polymerization pressure is normal pressure ~ 100 kg / cm ²
It is common to do in. The pressure is preferably -10 to 100 ° C. and atmospheric pressure to 50 kg / cm ² .

[0034]

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

Example 1 Isopropylcyclopentadienyl-1-fluorene synthesized by a conventional method was lithiated and reacted with zirconium tetrachloride to obtain isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dichloride.

2 mg of isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dimethyl obtained by further methylating the above product with methyllithium was dissolved in 10 ml of toluene, and 43 mg of triethylaluminum was added to and mixed with 1 liter of toluene. The 2 liter autoclave was charged. Then add propylene 3
kg / cm ² -G, 12.8 mg of triphenylmethanetetra (pentafluorophenyl) boron and 10 ml of toluene
The solution dissolved in was added to the autoclave to initiate polymerization. Polymerize at 20 ° C for 2 hours while maintaining 3 kg / cm ² -G,
Then, it was filtered and dried to obtain 69 g of a polymer (this was 164 k
g Equivalent to 1 g of polypropylene / zirconium. ).
According to ¹³ C-NMR, the syndiotactic pentad fraction was 0.88, and the intrinsic viscosity (hereinafter referred to as η) measured with a tetralin solution at 135 ° C was 1.13 and 1,2,4-trichlorobenzene. The ratio of the weight average molecular weight to the number average molecular weight (hereinafter referred to as MW / MN) was 2.2.

Subsequently, the toluene solution of isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dimethyl and triethylaluminum was stored at room temperature for 1 month, and then propylene was polymerized in the same manner to obtain 60 g of a polymer ( Is equivalent to 143 kg polypropylene / g zirconium). The syndiotactic pentad fraction by ¹³ C-NMR is 0.88, η is 1.20, and MW / MN is
It was 2.2, and the polymerization performance did not change even after storage.

Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 except that triethylaluminum was not added. The polymerization activity immediately after the preparation of the solution was similar to the result of Example 1, but when it was stored at room temperature for 1 month and then propylene was polymerized in the same manner, almost no polymerization activity was observed.

Example 2 10 mg of ethylenebistetrahydroindenylzirconium dimethyl and 0.39 g of triethylaluminum were dissolved in 10 ml of toluene instead of isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dimethyl. Polymerization of propylene was carried out in the same manner as in Example 1 except that methylaluminoxane was used instead of triphenylmethanetetra (pentafluorophenyl) boron to obtain 40 g of a polymer (this corresponds to 18.7 kg polypropylene / g zirconium 1 g). ). The polymer η was 0.74, the isotactic pentad fraction was 0.92, and the MW / MN was 2.2. After this metallocene compound solution was stored at room temperature for 1 month, propylene was similarly polymerized to obtain 45 g of a polymer (this corresponds to 21.0 kg polypropylene / zirconium 1 g). The η of the polymer was 0.72, the isotactic pentad fraction was 0.91, and the MW / MN was 2.2, and the polymerization performance did not change even after storage.

Example 3 Polymerization was carried out in the same manner as in Example 1 except that 0.52 g of triisobutylaluminum was used in place of triethylaluminum to obtain 70 g of a polymer. The polymer η is 0.
71, the syndiotactic pentad fraction is 0.88,
The MW / MN was 2.3. Even after the metallocene compound solution was stored at room temperature for 1 month and propylene was similarly polymerized, the polymerization performance was hardly changed.

Example 4 Polymerization was carried out in the same manner as in Example 1 except that cyclohexane was used instead of toluene to obtain 31 g of a polymer. The polymer had an η of 1.41, a syndiotactic pentad fraction of 0.87, and a MW / MN of 2.2. Even after the metallocene compound solution was stored at room temperature for 1 month and propylene was similarly polymerized, the polymerization performance was hardly changed.

[0042]

By carrying out the method of the present invention, the metallocene compound solution can be stored for a long period of time, and the polymerization can be carried out more stably than when the metallocene compound is used alone. It can be expected to obtain polyolefin with high activity and is extremely valuable industrially.

[Brief description of drawings]

FIG. 1 is a flow chart for facilitating understanding of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsumi Takeuchi 1-6 Takasago, Takaishi-shi, Osaka Mitsui Toatsu Chemical Co., Ltd.

Claims (2)

[Claims] 1. A) a transition metal metallocene compound represented by the following general formula (1) or (2): [Chemical 2] (In the formula, A and B or A ′ and B ′ are the same or different from each other, and an unsaturated hydrocarbon residue coordinated to the central atom, and R is a divalent straight chain which may have a side chain. A chain hydrocarbon residue or a residue in which a linear carbon atom thereof is substituted with a silicon atom, a germanium atom or a tin atom,
X represents a hydrocarbon residue having 1 to 20 carbon atoms, and M represents a metal atom selected from Groups 4 and 5 of the periodic table. ) B) A metallocene compound solution obtained by mixing an organoaluminum compound with c) in a hydrocarbon solvent. 2. A) a transition metal metallocene compound represented by the following general formula (3) or (4): [Chemical 4] (In the formula, A and B or A ′ and B ′ are the same or different from each other, and an unsaturated hydrocarbon residue coordinated to the central atom, and R is a divalent straight chain which may have a side chain. A chain hydrocarbon residue or a residue in which a linear carbon atom thereof is substituted with a silicon atom, a germanium atom or a tin atom,
X represents a hydrocarbon residue having 1 to 20 carbon atoms, and M represents a metal atom selected from Groups 4 and 5 of the periodic table. ) B) An organoaluminum compound and c) a metallocene compound solution, which is stored by dissolving it in a hydrocarbon solvent.