JPH0762013A - Production of polyolefin - Google Patents

Abstract

PURPOSE:To obtain a polyolefin having a desired molecular weight and a wide molecular weight distribution by making a hydrosilyl group-containing compound exist in polymerizing an olefin in the presence of as catalyst composed of a transition metal compound, aluminoxane, etc. CONSTITUTION:In polymerizing an olefin by using a catalytic component composed of a ligand-containing transition metal compound and aluminoxane or a combination of a reaction product of the metal compound and an organometallic compound and a compound to be reacted with the reaction product to form an ionic compound, the polymerization is carried out in the presence of a hydrosilyl group-containing compound. A transition metal compound of the formula I or formula II (A and B are monofunctional to bifunctional unsaturated hydrocarbon residue or nitrogen or oxygen bonded to M, etc.; A' and B' are unsaturated hydrocarbon residue crosslinked with R, etc.; R is bifunctional nitrogen, oxygen, etc.; M is metal of group 4 to group 5 of the periodic table; M is halogen or carbon bonded to M, etc.) is used as the transition metal compound. A compound of the formula RnSiH4-n (R is hydrocarbon residue; (n) is 1-3) is used as the hydrosilyl group-containing compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a polyolefin. Specifically, it relates to a method for producing a polyolefin having a desired molecular weight and a wide molecular weight distribution.

[0002]

As an olefin polymerization catalyst, a transition metal compound such as a metallocene compound having a group having a conjugated π electron, particularly cyclopentadiene and its derivative as a ligand, and an alkyl obtained by the reaction of trialkylaluminum and water. A combination with aluminoxane is known. For example, JP-A-58-19309 discloses a method for polymerizing biscyclopentadienyl zirconium dichloride and olefins using methylaluminoxane as a catalyst, and JP-A-61-130314 and JP-A-61-264010. Kohei
1-301704 and JP-A-2-41303 disclose isotactic poly α-olefins or syndiotactic poly α-
Process for producing olefins and their stereoregular poly α-
Polymerization catalysts for producing olefins are disclosed.

On the other hand, it has been reported that a cationic metallocene compound having cyclopentadiene and its derivative as a ligand polymerizes an olefin without using methylaluminoxane. For example, RFJORDAN et al., J. Am. Chem. Soc., 1986, Vol. 108, page 7410, has tetraphenylborane as an anion, and a zirconium cation complex having a biscyclopentadienyl group and a methyl group as a ligand is ethylene. It has been reported that it has a polymerization activity. Turner et al., J. Am. Chem. Soc., 1989 111
Vol. 2728, it is reported that the ion pair type zirconium complex also has ethylene polymerization activity. Further Za
mbelli et al., Macromolecules, 1989, Vol. 22, pp. 2186-2189, reported that isotactic polypropylene was produced by polymerizing propylene with a combination of a zirconium compound having a cyclopentadiene derivative as a ligand and trimethylaluminum and fluorodimethylaluminum. It reports that it can be obtained.

[0004]

The above method is an excellent method in that the activity per transition metal is good, and the stereoregularity and tacticity of the obtained polymer can be selected depending on the kind of the transition metal compound used. is there.
When producing a polymer having a desired molecular weight using these catalysts, hydrogen is used as a chain transfer agent to control the molecular weight by controlling the amount of hydrogen added. However, depending on the type of the transition metal compound, the addition of hydrogen may cause a reaction to cause no polymerization activity, so that a polymer having a desired molecular weight cannot be obtained. Further, even if any of the above catalysts is used, the molecular weight distribution of the obtained polymer is very narrow, around 2, and there is a problem in the moldability of the polymer. It is described in JP-A-3-212408 that a polymer having a wide molecular weight distribution can be obtained by polymerizing with at least two kinds of transition metal compounds in order to broaden the molecular weight distribution. The polymer obtained by the method of polymerizing using two kinds of transition metal compounds has a broad molecular weight distribution when measured by gel permeation chromatography, but the distribution shows two or more peaks. Since the polymer has a high molecular weight, the polymer has a slump when formed into a film, and the physical properties of other molded products are deteriorated, so that only a product having a low commercial value can be obtained.

[0005]

[Means for Solving the Problems] The inventors of the present invention have made extensive studies on a method for solving the above problems and obtaining a polyolefin having a desired molecular weight and having a wide molecular weight distribution. As a result, a specific compound is effective for controlling the molecular weight. It was found that the present invention has been completed.

That is, in the present invention, a reaction product of a transition metal compound having a ligand and an aluminoxane, or a transition metal compound having a ligand and an organometallic compound is reacted with the reaction product to form an ionic compound. A method for producing a polyolefin using a catalyst component comprising a combination with a compound, wherein the polymerization reaction is carried out in the presence of a compound having a hydrosilyl group.

As the transition metal compound having a ligand used in the present invention, the compounds described in the above-mentioned documents can be exemplified. In addition, the compounds represented by the following general formulas (Formula 4) or (Formula 5) (wherein , A and B are monovalent or divalent unsaturated hydrocarbon residues, or the same or different ligands containing a nitrogen atom, an oxygen atom, a silicon atom, a phosphorus atom or a sulfur atom bonded to M. , A ′ and B ′ are the same or different monovalent or divalent unsaturated hydrocarbon residues bridged by R, or a nitrogen atom, an oxygen atom bonded to M,
A ligand containing a phosphorus atom or a sulfur atom, and R is a linear saturated hydrocarbon which may have a residue or a side chain containing a divalent nitrogen atom, oxygen atom, silicon atom, phosphorus atom or sulfur atom. A residue or a residue in which some or all of the linear carbon atoms thereof are substituted with silicon atoms, germanium atoms or tin atoms, and M is a metal atom selected from Group 4 or 5 of the periodic table. , And X represents a ligand containing a halogen atom, a carbon atom, a nitrogen atom, an oxygen atom, a silicon atom, a boron atom, a phosphorus atom or a sulfur atom bonded to M. The transition metal compound which has the ligand represented by these is illustrated.

[0008]

[Chemical 4]

[0009]

[Chemical 5]

Examples of the unsaturated hydrocarbon residue represented by A and B include monocyclic or polycyclic groups having conjugated π electrons having 5 to 50 carbon atoms, and specific examples include cyclohexyl. Petadienyl or some or all of its hydrogens replaced by a hydrocarbon residue having 1 to 10 carbon atoms (wherein the hydrocarbon residue has a structure in which its terminal is again bound to the cyclopentadiene ring) Or a polycyclic aromatic hydrocarbon residue such as indenyl or fluorenyl, or one in which a part or all of the hydrogen thereof is substituted with a hydrocarbon residue having 1 to 10 carbon atoms.
Further, as a ligand containing a nitrogen atom, an oxygen atom, a silicon atom, a phosphorus atom or a sulfur atom bonded to M, COR ′,
NR ' ₂ , OR', OSiR ' ₃ , SiR' ₃ , GeR ' ₃ , PR' ₂ , POR ' ₂ ,
Examples include ligands represented by SR ', SOR', and SO ₂ R '(R' is hydrogen or a hydrocarbon having 1 to 20 carbon atoms or a residue in which some of them are substituted with heteroatoms). To be done. These may be the same as or different from each other.

The ligand represented by A'or B'is
Monocyclic or polycyclic conjugated π-electrons with 5 to 50 carbon atoms
Groups with children, COR ', NR'₂, OR ', OSiR'₃, SiR '₃ ,
GeR ' ₃ , PR '₂, POR '₂ , SR ', SOR', SO₂R '(R' is hydrogen
Or a hydrocarbon having 1 to 20 carbon atoms or one of them
Transition represented by a residue in which one or more of the atoms are replaced by a hetero atom
The ligand bonded to the metal atom M is exemplified. these
May be the same or different from each other. Where A'and
And B'have a structure bridged by R.
It

The divalent group represented by R includes -O- and -S-.
, -SS-, -SO-, -SO _2- , -CO-, -NR "-, -PR"-, -PO
R "-, -OSiR" ₂ O-, or a methylene group represented by the following general formula (Formula 6) or a part or all of the carbon atoms of the methylene group is substituted with a silicon atom, a germanium atom, or a tin atom. Examples are silylene groups, germylene groups, and stannylene groups.

[0013]

[Image Omitted]-(R " ₂ C) n- (R" ₂ Si) m- (R " ₂ Ge) p- (R" ₂ Sn) q- (wherein R "is a hydrogen atom or a carbon atom number 1 2 R ″ may represent the same or different and n, m, p and q are integers of 0 to 4 and the following formula 1 ≦
It represents an integer satisfying n + m + p + q ≦ 4. )

X is a halogen atom such as fluorine, chlorine, bromine or iodine, or CR ' ₃ , CH ₂ SiR' ₂ , COR ', NR' ₂ , OR ',
OSiR ' ₃ , SiR' ₃ , GeR ' ₃ , PR' ₂ , POR ' ₂ , SR', SOR ',
SO ₂ R ′ (R ′ is hydrogen or a hydrocarbon having 1 to 20 carbon atoms or a residue in which some of them are substituted with a hetero atom) and the like can be exemplified.

In the present invention, when a catalyst comprising a combination of a transition metal compound having a ligand and an aluminoxane is used, the aluminoxane is obtained by hydrolyzing a trialkylaluminum with the following general formula (Formula 7) or Examples thereof include compounds represented by Chemical Formula 8, and among these, a methylaluminoxane in which R is a methyl group and n is 5 or more is preferably used. The ratio of the aluminoxane to be used with respect to the transition metal compound is 1 to 10000 mol times, usually 10 to 5000 mol times.

[0016]

[Chemical 7]

[0017]

[Chemical 8]

Ion pair compounds when a catalyst component comprising a combination of a compound (ion pair compound) which reacts with a reaction product of a transition metal compound having a ligand and an organometallic compound to form an ionic compound is used. As the compound, a compound represented by the following general formula (Formula 9) is used.

[0019]

[Chemical Formula 9] [Q] ⁺ [Y] ^-

Here, Q is a cation component of the ionic compound, and examples thereof include carbonium cation, tropylium cation, ammonium cation, oxonium cation, sulfonium cation, and phosphonium cation. Specific examples of these cations include triphenyl carbonium, diphenyl carbonium, cycloheptatrienium, tributyl ammonium, N, N.
-Dimethylanilinium, dipropylammonium, dicyclohexylammonium, triphenylphosphonium, trimethylphosphonium, triphenylsulfonium, triphenyloxonium, triethyloxonium, pyrylium and the like.

Y is an anion component of an ionic compound, and examples thereof include a boron compound anion, an aluminum compound anion, a gallium compound anion, a phosphorus compound anion, an arsenic compound anion, and an organic antimony compound anion. Phenyl boron,
Examples thereof include tetrakis (pentafluorophenyl) boron, tetraphenylaluminum, tetrakis (pentafluorophenyl) aluminum, tetraphenylgallium, tetrakis (pentafluorophenyl) gallium, hexafluoroline, hexafluoroarsenic and hexafluoroantimony.

In the present invention, the organometallic compound to be reacted with the transition metal compound is a metal atom of Groups 1, 2, 12 and 13 of the Periodic Table, preferably aluminum, zinc or magnesium, halogen atom, oxygen atom or When a hydrogen atom or a residue such as alkyl, alkoxy or aryl is coordinated and a plurality of ligands are present, they may be the same or different, but at least one of them is an alkyl group. Some are exemplified. For example, an alkyl metal compound in which one or more alkyl residues having 1 to 12 carbon atoms are coordinated, an alkyl metal halide in which the above alkyl residue and another atom or residue are coordinated, an alkyl metal alkoxide, etc. It is illustrated. Among them, an alkylaluminum compound in which at least one alkyl residue having 2 or more carbon atoms is coordinated is preferably used.

Examples of preferred organometallic compounds in which the metal atom is aluminum include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tributylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum. ,
Triheptyl aluminum, trioctyl aluminum, tridecyl aluminum, isoprenyl aluminum, diethyl aluminum hydride, diisopropyl aluminum hydride, diisobutyl aluminum hydride, diethyl aluminum chloride, di-n-propyl aluminum chloride, diisopropyl aluminum chloride, diisobutyl aluminum chloride, diethyl aluminum Ethoxide, diisopropyl aluminum isopropoxide, ethyl aluminum sesquichloride, isopropyl aluminum sesquichloride, isobutyl aluminum sesquichloride, ethyl aluminum dichloride, isopropyl aluminum dichloride, isobutyl aluminum dichloride, ethyl acetate Mini Umm diisopropoxide, and the like.

The method for treating the transition metal compound with the organometallic compound is not particularly limited, and both may be simply mixed. Usually, the transition metal compound is solid, and the organometallic compound is liquid or solid in many cases, and therefore it is preferable to treat it in a hydrocarbon solvent. The ratio of the organic metal compound used to the transition metal compound is 1 to 100,000 mol times, usually 1
~ 5000 times mole. The treatment temperature is not particularly limited,
Usually, it is preferably carried out at a temperature of -20 to 100 ° C. The temperature at which these mixtures are stored is also not particularly limited, but it is preferable to store at a temperature of −20 to 100 ° C. as well. The treatment time is not particularly limited, and when both are solutions, it may be at the point of time when they are uniformly mixed, and when insolubles are present, they can be used any time after they have been dissolved in the solvent. Of course, as described above, it is also possible to store it as it is until use and use it as needed. Further, the concentration of the reaction product in the hydrocarbon solvent is stable even at a considerably high concentration as described above, and therefore it is not particularly limited, but is usually 10 ^-7 to 1 mol / liter, preferably the molar concentration based on the metallocene compound. Is 10 ^-5
~ 0.1 mol / l.

The amount of the above-mentioned ionic compound-forming compound used is based on the transition metal compound used in the catalyst.
It is 0.1 to 100,000 mole times, usually 0.5 to 10,000 mole times.

The compound having a hydrosilyl group used in the present invention is a silane compound represented by the following general formula (Formula 10) (wherein R represents a hydrocarbon residue and n represents an integer of 1 to 3). is there.

[0027]

[Image Omitted] R _n SiH _4-n

As the compound having a hydrosilyl group,
Methylsilane, ethylsilane, propylsilane, butylsilane, pentylsilane, hexylsilane, heptylsilane, octylsilane, dimethylsilane, diethylsilane, dipropylsilane, dibutylsilane, dipentylsilane, dihexylsilane, diheptylsilane, dioctylsilane, trimethylsilane, Examples thereof include triethylsilane, tripropylsilane, tributylsilane, tripentylsilane, trihexylsilane, triheptylsilane, trioctylsilane, and branched alkyl groups thereof.

The ratio of the compound having a hydrosilyl group to the above transition metal compound varies depending on the molecular weight of the target polymer, but is usually 1/100000 of that of propylene.
If it is less than 1/10, it is not effective for controlling the molecular weight, and if it is used more than this, not only the effect is not improved, but also the activity is greatly reduced and it is not practical.

Examples of the solvent used in the preparation, polymerization or treatment of the catalyst using the catalyst component of the present invention include propane, butane, isobutane, pentane, hexane, heptane, octane, nonane, decane, cyclopentane, cyclohexane, Saturated hydrocarbon compounds such as cycloheptane and methylcyclohexane, aromatic hydrocarbon compounds such as benzene, toluene and xylene, and halogenated hydrocarbon compounds such as methylene chloride and chlorobenzene can also be used.

In the present invention, as the olefin, 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-1
In addition to linear α-olefins such as 3-methylbutene-1,4-
Branched α such as methylpentene-1,4,4-dimethylpentene-1
-Olefins and cycloolefins such as cyclopentene, cyclooctene and norbornene are exemplified, and α-
Not only olefins alone but also mixtures with one another or with small amounts of ethylene and dienes are indicated. Further, styrene, α-methylstyrene and the like can be used.

The polymerization conditions are not particularly limited, and a solvent polymerization method using an inert medium, a bulk polymerization method substantially free of an inert medium, or a gas phase polymerization method can be used.
As the polymerization temperature and the polymerization pressure, general conditions used in a known method are used, and as the polymerization temperature, -100 to
It is common to carry out at 200 ° C. and a polymerization pressure of atmospheric pressure to 100 kg / cm ² -G.

[0033]

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

Example 1 Methylaluminoxane (manufactured by Tosoh Akzo, polymerization degree 1
6.2) 0.22 g is dissolved in 1 liter of toluene and put in a 2 liter autoclave, and 0.1 g of diethylsilane is further added.
Charged. Charge propylene to 5kg / cm ² -G,
Diphenylmethylene (cyclopentadienyl-2,6-di-t
ert-Butylfluorenyl) zirconium dichloride 1 mg
Was dissolved in 50 ml of toluene and polymerized at 20 ° C. for 2 hours. Unreacted propylene was then purged and the polymer was filtered off, dried and weighed.
g of polymer was obtained. This polymer has a syndiotactic pentad fraction of 0.95 according to ¹³ C-NMR,
Intrinsic viscosity (hereinafter referred to as η) measured with tetralin solution at ℃ 1.49, G using 1,2,4-trichlorobenzene as solvent
The ratio of the weight average molecular weight to the number average molecular weight measured by PC (hereinafter referred to as MW / MN) was 5.3.

Comparative Example 1 Polymerization of propylene was carried out in the same manner as in Example 1 except that 2N liters of hydrogen was used instead of diethylsilane.
A polymer of The syndiotactic pentad fraction of this polymer is 0.95, η is 1.57 and MW / MN is 2.3.
Met.

Example 2 Diphenylmethylene (cyclopentadienyl-2,6-di-t
ert-Butylfluorenyl) zirconium dichloride Isopropenyl (cyclopentadienyl-1-fluorenyl) zirconium dichloride was used as the catalyst component in the same manner as in Example 1 except that the amount of diethylsilane was 0.02 g. When propylene was polymerized, 25.8 g of a polymer was obtained. The syndiotactic pentad fraction of this polymer was 0.92, η was 1.23, and MW / MN was 4.8.

Comparative Example 2 Polymerization of propylene was carried out in the same manner as in Example 2 except that 2N liter of hydrogen was used instead of diethylsilane.
12.7 g of polymer was obtained. The syndiotactic pentad fraction of this polymer is 0.92, η is 1.25, MW / MN
Was 2.2.

[0038]

By carrying out the method of the present invention, it is possible to produce a highly active polyolefin having a controlled molecular weight per catalyst and a wide molecular weight distribution with good productivity.
It is extremely valuable industrially.

[Brief description of drawings]

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

Claims (3)

[Claims] 1. A reaction product of a transition metal compound having a ligand and an aluminoxane, or a transition metal compound having a ligand and an organometallic compound, and a compound which reacts with the reaction product to form an ionic compound. A method for producing a polyolefin using a catalyst component comprising a combination, wherein the polymerization reaction is carried out in the presence of a compound having a hydrosilyl group. 2. A transition metal compound having a ligand is represented by the following general formula (Chemical formula 1) or (Chemical formula 2) (wherein A and B are 1
A divalent or divalent unsaturated hydrocarbon residue, or mutually identical or different ligands containing a nitrogen atom, an oxygen atom, a silicon atom, a phosphorus atom or a sulfur atom bonded to M, A ′ and B ′ Is a monovalent or divalent unsaturated hydrocarbon residue bridged with R, or a ligand containing a nitrogen atom, an oxygen atom, a phosphorus atom or a sulfur atom bound to M, and R is A linear saturated hydrocarbon residue which may have a residue or a side chain containing a divalent nitrogen atom, oxygen atom, silicon atom, phosphorus atom or sulfur atom, or a part or all of the linear carbon atom thereof Is a residue substituted with a silicon atom, a germanium atom or a tin atom, M is a metal atom selected from Group 4 or Group 5 of the periodic table, and X is a halogen atom, a carbon atom bonded to M, Nitrogen atom, oxygen atom, silicon atom, boron atom, Shows a ligand containing an atom or a sulfur atom. ) The method according to claim 1, represented by [Chemical 1] [Chemical 2] 3. The compound according to claim 1, wherein the compound having a hydrosilyl group is represented by the following general formula (Formula 3) (wherein R represents a hydrocarbon residue and n represents an integer of 1 to 3). Method. Embedded image R _n SiH _4-n