JP2951763B2 - Metallocene compound solution and storage method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

BACKGROUND ART As an olefin polymerization catalyst, a combination of 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. It has been known. For example, JP-A-58-19309 discloses a method for polymerizing olefins using biscyclopentadienyl zirconium dichloride and methylaluminoxane as catalysts. JP-A-61-130
314, JP-A-61-264010, JP-A-1-301704 and JP-A-2-4
1303 discloses a method for producing isotactic poly-α-olefin or syndiotactic poly-α-olefin and a polymerization catalyst for producing these stereoregular poly-α-olefins. All of the catalyst systems used use aluminoxane as a cocatalyst.

[0003] On the other hand, studies have been made on a homogeneous Ziegler-Natta catalyst which does not use 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. Recently, an isolated cationic metallocene compound having cyclopentadiene or a derivative thereof as a ligand, even if methylaluminoxane as a co-catalyst is not present,
It has been reported that olefins alone have polymerization activity.

For example, RFJORDAN and the like are described in J. Am. Chem. Soc.,
1986 108, 7410-7411, zirconium cation complex with tetraphenylborane as anion and two cyclopentadienyl and methyl groups as ligands, with donors such as tetrahydrofuran as ligands It has been reported that the isolated complex has ethylene polymerization activity in methylene chloride.

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

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

[0007]

A polymerization method using a metallocene compound and an aluminoxane described in JP-A-58-19309 and the like, a method using a cationic metallocene complex such as RFJORDAN et al., TURNER et al., And a trimethyl ester described by Zambelli et al. Α-olefin polymerization methods using metallocene compounds as catalysts, such as polymerization methods using aluminum, dimethylaluminum fluoride and zirconium complexes, have high catalytic activity, a narrow molecular weight distribution of about 2 and a composition distribution in copolymerization. Is a catalyst having such characteristics that a narrow product can be obtained.

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

[0009]

Means for Solving the Problems The present inventors have solved the above-mentioned problems and have intensively studied a metallocene solution which does not show a decrease in activity even after being stored for a long period of time, and completed the present invention.

[0010] Specifically, the present invention, a) a transition metal metallocene compound represented by the following chemical formula 3 or formula 4

[0011]

Embedded image

[0012]

Embedded image Wherein A and B or A ′ and B ′ are the same or different from each other,
Aroma selected from tadiene, indene and fluorene
If some of the hydrogens of the aromatic compounds or of these aromatic compounds
All of which are substituted with 1 to 10 hydrocarbon residues (this
Here, the hydrocarbon residue has a structure in which the terminal is bonded to the aromatic ring again.
The may be granulated), R is substituted carbon atom may have a side chain divalent straight-chain hydrocarbon residue or a straight chain with a silicon atom, a germanium atom or a tin atom X represents a hydrocarbon residue having 1 to 20 carbon atoms;
Shows the <br/> metal atom selected from titanium, zirconium and hafnium. ) B) a main <br/> Tarosen compound solution storage method which is characterized in that the organic aluminum compound c) is stored dissolved in a hydrocarbon solvent.

In the present invention, the above general formula 3
As the transition metal compound represented by 4 , a compound generally known as a metallocene compound can be exemplified. These compounds are transition metal compounds having a group having a conjugated π electron as a ligand, wherein A and B or A ′ and B ′ are the same or different cyclopentadiene,
Aromatic compounds selected from butene and fluorene,
Means that some or all of the hydrogens of these aromatic compounds are 1
Substituted with hydrocarbon residues of 10 to 10 (here, hydrocarbon
Even if the residue has a structure in which the terminal is bonded to the aromatic ring again
Good) , R is a divalent linear hydrocarbon residue which may have a side chain or part or all of the 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 titanium, zirconium and hafnium .

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. Specifically, cyclopetadienyl or a compound in which part or all of hydrogen is substituted by a hydrocarbon residue having 1 to 10 carbon atoms (here, carbon The hydrogen residue may have a structure in which its terminal is again bonded to the cyclopentadiene ring.)
Alternatively, polycyclic aromatic hydrocarbon residues such as indenyl and fluorenyl, or those obtained by substituting part or all of the hydrogens thereof with a hydrocarbon residue having 1 to 10 carbon atoms are exemplified.

As the divalent group represented by R, a methylene group represented by the following general formula 5 or a part or all of carbon atoms of the methylene group is a silicon atom, a germanium atom,
Alternatively, those having a silylene group, a germylene group, or a stannylene group substituted with a tin atom are exemplified.

[0016]

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 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, and an aryl group such as a phenyl group, a benzyl group and a cyclopentadienyl group.

In the present invention, general formula 3 or 4
Is brought into contact with an organoaluminum compound in a hydrocarbon solvent to synthesize a uniform solution. As the organoaluminum compound used here, a halogen atom, an oxygen atom, a hydrogen atom, an alkyl group,
Residues such as an alkoxy group and an aryl group are coordinated,
When there are a plurality of ligands, the ligands may be the same or different, and at least one of them is an alkyl group. For example, an alkyl aluminum compound having 1 to 3 alkyl residues having 1 to 12 carbon atoms bonded thereto, an alkyl aluminum halide, an alkyl aluminum hydride, an alkyl aluminum alkoxide, or the like can be used. For example, trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum,
Tributyl aluminum, trihexyl aluminum,
Trioctylaluminum, dimethylaluminum chloride, diethylaluminum chloride, diisopropylaluminum chloride, diisopropylaluminum isopropoxide, ethylaluminum dichloride, diisobutylaluminum hydride, ethylaluminum diisopropoxide, isobutylaluminum ethoxide, etc., and these aluminum compounds Among them, a trialkylaluminum compound is particularly preferred.

The method for producing the transition metal metallocene compound solution can be easily obtained by contacting the transition metal metallocene compound with an organoaluminum compound 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 is considered that the metallocene compound is solubilized in the hydrocarbon solvent. In addition, even if the metallocene compound solution thus obtained is stored for a long period of time, the metallocene compound is decomposed to form insolubles, and the activity decreases even when used as a polymerization catalyst for olefins. It can be prevented from becoming active. The temperature at which they are brought into contact is not particularly limited, but usually it is preferably carried out at a temperature of -20 to 100 ° C. The temperature at which they are stored is not particularly limited, but it is also preferable to store them at a temperature of -20 to 100 ° C.

Here, 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 excessive amount of the organoaluminum compound is used, but if it is used in an excessively large amount, the activity will not be further improved and it will be uneconomical.

Examples of the hydrocarbon solvent used in the present invention include benzene, besides 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 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 is usually 10 ^-8 to 1 mol / l, preferably 10 ^{-7 to} 0.1 mol / l as the metallocene compound concentration. .

As described above, the metallocene compound solution of the present invention is used in combination with a conventionally known organometallic compound for olefin polymerization or in combination with a compound capable of reacting with a metallocene compound to form an ionic compound. Can be As the organometallic compound for olefin polymerization, the following general formula 6 or 7

[0025]

Embedded image

[0026]

Embedded image (Wherein, R is an alkyl group having 1 to 6 carbon atoms and n is an integer of 1 or more).
It is produced by various methods, for example, by reacting up to 3 moles of water. Examples of the trialkylaluminum include trimethylaluminum, triethylaluminum, tripropylaluminum, trin-butylaluminum, triisobutylaluminum, trihexylaluminum, and mixtures thereof.

Examples of the compound which 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 them into ionic compounds. If necessary, it reacts with the transition metal compound represented by the above general formula 3 or 4 to transfer the group represented by X to the Lewis acid compound as an electron pair to form a transition metal cation compound. The Lewis acid does not recombine or strongly coordinate with the transition metal cation compound generated by the Lewis acid itself or the anion that has formed an ion pair, thereby inactivating the polymerization activity.

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

Examples of the anion of the ionic compound include:
Organic boron compound anion, organic aluminum compound anion, organic phosphorus compound anion, organic arsenic compound anion, organic antimony compound anion, etc., and metal oxides known as metal halides and solid acids as electrophilic compounds And the like.

The olefin used for the polymerization includes ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, and the like.
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 include branched α-olefins such as 4-methylpentene-1, 4,4-dimethylpentene-1 and the like. These olefins may be used alone or in a mixture with each other or in a mixture with a small amount of a polyene such as a diene. Can be polymerized.

The polymerization conditions using such an olefin polymerization catalyst are not particularly limited, and a solvent polymerization method using an inert medium, a bulk polymerization method substantially free of an inert medium, and a gas phase polymerization method are also used. The polymerization temperature is -10
0 to 200 ° C, polymerization pressure is normal pressure to 100 kg / cm ²
It is common to do with. Preferably, the temperature is from 10 to 100 ° C. and the atmospheric pressure is 50 kg / cm ² .

[0032]

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

Example 1 Isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dichloride was obtained by lithiating isopropylcyclopentadienyl-1-fluorene synthesized according to a conventional method and reacting it with zirconium tetrachloride.

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, 43 mg of triethylaluminum was added and mixed, and 1 liter of toluene was added. The charged 2 liter autoclave was charged. Then add propylene and add 3
kg / cm ² -G, 12.8 mg of triphenylmethanetetra (pentafluorophenyl) borane was added to 10 ml of toluene.
Was added into an autoclave to initiate polymerization. Polymerizing at 20 ° C for 2 hours while maintaining 3kg / cm ² -G,
Then, the mixture 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 measured with 1.13 and 1,2,4-trichlorobenzene. The ratio between the weight average molecular weight and the number average molecular weight (hereinafter referred to as MW / MN) was 2.2.

Next, the toluene solution of isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dimethyl and triethylaluminum was stored at room temperature for one month, and propylene was polymerized in the same manner to obtain 60 g of a polymer. Is equivalent to 143 kg of polypropylene / g of zirconium.) The syndiotactic pentad fraction by ¹³ C-NMR was 0.88, η was 1.20, and MW / MN was
2.2, and the polymerization performance did not change 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 solution preparation was the same as the result of Example 1, but after storing at room temperature for one month, propylene was polymerized in the same manner, and almost no polymerization activity was observed.

Example 2 Instead of isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dimethyl, 10 mg of ethylenebistetrahydroindenyl zirconium dimethyl and 0.39 g of triethylaluminum were dissolved in 10 ml of toluene. Propylene was polymerized in the same manner as in Example 1 using methylaluminoxane instead of triphenylmethanetetra (pentafluorophenyl) boron to obtain 40 g of a polymer (corresponding to 18.7 kg of polypropylene / 1 g of zirconium). ). The η of the polymer was 0.74, the isotactic pentad fraction was 0.92, and the MW / MN was 2.2. After storing this metallocene compound solution at room temperature for one month, propylene was polymerized in the same manner to obtain 45 g of polymer (this corresponds to 21.0 kg of polypropylene / 1 g of zirconium). The η of the polymer was 0.72, the isotactic pentad fraction was 0.91, the MW / MN was 2.2, and the polymerization performance did not change 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 instead of triethylaluminum, to obtain 70 g of a polymer. The η of the polymer is 0.
71, syndiotactic pentad fraction is 0.88,
MW / MN was 2.3. After storing this metallocene compound solution at room temperature for one month, polymerization of propylene in the same manner showed almost no change in polymerization performance.

Example 4 Polymerization was carried out in the same manner as in Example 1 except that cyclohexane was used instead of toluene. As a result, 31 g of a polymer was obtained. The η of the polymer was 1.41, the syndiotactic pentad fraction was 0.87, and the MW / MN was 2.2. After storing this metallocene compound solution at room temperature for one month, polymerization of propylene in the same manner showed almost no change in polymerization performance.

[0040]

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 in the polymerization than when the metallocene compound is used alone. It is expected that polyolefins can be obtained with high activity and are extremely valuable industrially.

[Brief description of the drawings]

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

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-115004 (JP, A) JP-A-4-211404 (JP, A) JP-T2-501227 (JP, A) JP-T-5 505838 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 4/60-4/70

Claims (1)

(57) [Claims] 1. A a) ## STR1 ## and a transition metal metallocene compound represented by the following chemical formula 1 or formula 2 Embedded image Wherein A and B or A ′ and B ′ are the same or different from each other,
Aroma selected from tadiene, indene and fluorene
If some of the hydrogens of the aromatic compounds or of these aromatic compounds
All of which are substituted with 1 to 10 hydrocarbon residues (this
Here, the hydrocarbon residue has a structure in which the terminal is bonded to the aromatic ring again.
The may be granulated), R is substituted carbon atom may have a side chain divalent straight-chain hydrocarbon residue or a straight chain with a silicon atom, a germanium atom or a tin atom X represents a hydrocarbon residue having 1 to 20 carbon atoms;
Shows the <br/> metal atom selected from titanium, zirconium and hafnium. A) a method for storing a metallocene compound solution, wherein b) an organoaluminum compound is dissolved in a hydrocarbon solvent and stored.