JP3197314B2 - Method for producing polyolefin having wide molecular weight distribution - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polyolefin having a wide molecular weight distribution. More specifically, the present invention relates to a method for producing a highly stereoregular polyolefin having a wide molecular weight distribution by combining specific compounds.

[0002]

2. Description of the Related Art As an olefin polymerization catalyst, a combination of a metallocene compound 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.

[0004] 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 without the coexistence of methylaluminoxane as a cocatalyst. Have been.

For example, RFJORDAN and the like are described in J. Am. Chem. Soc.,
1986 108, pp. 7410-7411, a 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 has been reported that the isolated complex has ethylene polymerization activity in methylene chloride.

Also, Turner et al., J. Am. Chem. Soc., 1989
111 volume 2728-2729 pages
A transition metal compound capable of reacting with a proton having a cyclopentadienyl group or a derivative thereof having a substituent at 36 as a ligand and a compound providing a stable anion having a cation capable of providing a proton It has been reported that an ion-pair type metallocene complex has olefin polymerization activity. Furthermore, Zambel
Li et al., Macromolecules, 1989, Vol. 22, pp. 2186-2189, propylene is polymerized by a catalyst combining a zirconium compound having a cyclopentadienyl group derivative as a ligand and trimethylaluminum and fluorodimethylaluminum, and isotactic. It is reported that polypropylene can be obtained. In this case, too, it is considered that the active species is a metallocene compound in an ion pair form.

[0007]

When a polyolefin is produced by polymerizing an olefin using a catalyst comprising these transition metal metallocene compounds, a very narrow polyolefin having a molecular weight distribution of about 2 is produced in each case. However, since polyolefins of various molecular weight distributions are required depending on the field of application of polyolefins, Japanese Patent Application Laid-Open Nos. 60-35006 and 60-35008 disclose different metallocene catalysts by using two or more different metallocene catalysts. Thus, a method for producing a polymer having a wide molecular weight distribution is disclosed.

However, it is known that the above-mentioned catalyst systems have different structures of polymers produced by the respective catalyst systems, and it is extremely difficult to produce polyolefins having different molecular weight distributions in the same polymerization system by changing the catalyst. In particular, in the polymerization of α-olefins such as propylene, it is extremely difficult to change the molecular weight distribution only because the stereoregularity of the polymer obtained by the catalyst is different.

[0009]

Means for Solving the Problems The inventors of the present invention have solved the above-mentioned problems and have intensively studied a method for producing a polymer having a wide molecular weight distribution, and completed the present invention. That is, the present invention
a) the following general formula 3 or 4 wherein A and B or A ′ and B ′ are the same or different monovalent or divalent unsaturated hydrocarbon residues or nitrogen atoms bonded to M, A ligand containing an oxygen atom, a silicon atom, a phosphorus atom or a sulfur atom, wherein R is a divalent nitrogen atom, an oxygen atom, a silicon atom,
A residue containing a phosphorus atom or a sulfur atom, or a straight-chain saturated hydrocarbon residue which may have a side chain, or part or all of the straight-chain carbon atoms thereof being substituted with a silicon atom, a germanium atom or a tin atom; X represents a metal atom selected from Group 4 of the periodic table, and X represents a halogen atom, a carbon atom, a nitrogen atom, an oxygen atom, a silicon atom,
A transition metal compound represented by a ligand containing a phosphorus atom or a sulfur atom)

[0010]

Embedded image

[0011]

Embedded image b) gold selected from aluminum, zinc and magnesium
After reacting with an organometallic compound of the genus , c) polymerizing an olefin by using at least two or more compounds that react with a reaction product of the transition metal compound (a) and the organometallic compound (b) to become a stable anion This is a method for producing a polyolefin having a wide molecular weight distribution.

In the present invention, the transition metal compound includes
The transition metal compound represented by the general formula (3) or (4) can be exemplified.

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.

_{Furthermore, COR ', NR' 2,} OR ', OSiR' 3, SiR '
_{3, GeR '3, PR'} 2, POR '2, SR', SOR replaced with _{', SO 2 R' (R} ' is a hydrocarbon or several hetero atoms of those 20 number of 1 hydrogen or carbon And a ligand bonded to the transition metal atom M represented by the following formula: Here, R ′ of A ′ and B ′ has a structure cross-linked by R.

The divalent group represented by R is -O-, -S-
, -SS-, -SO-, -SO _2- , -CO-, -NR "-, -PR"-, -PO
R "-, -OSiR" ₂ O- or a methylene group represented by the following formula 5, or a silylene group in which part or all of the carbon atoms of the methylene group are substituted with a silicon atom, a germanium atom, or a tin atom; A germylene group and a stannylene group are exemplified.

[0016]

## STR5 ##-(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 having 1 carbon atom. And two R ″ s may be the same or different, and n, m, p and q are integers of 0 to 4 and the following formula 1 ≦
represents an integer satisfying n + m + p + q ≦ 4. )

[0017] As the X fluorine, chlorine, bromine, halogen atom or CR iodine, etc. _{'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).

The transition metal compound (a) and the organometallic compound
The compound that becomes a stable anion by reacting with the reactant with (b) is an ionic compound or an electrophilic compound formed from an ion pair of a cation and an anion, and a transition metal compound (a) and an organometallic compound. It reacts with the reactant (b) to form a polymerization active species. Among them, the ionic compound is represented by Formula 6 below.

[0019]

[Omitted] [Q] m [Y] m -

In Formula 6, Q is a cation component of an ionic compound, and examples thereof include a carbonium cation, a tropylium cation, an ammonium cation, an oxonium cation, a sulfonium cation, and a phosphonium cation. Specific examples of these cations include triphenylcarbonium, diphenylcarbonium, cycloheptatrienium, tributylammonium, N, N-dimethylanilinium, dipropylammonium, dicyclohexylammonium, triphenylphosphonium, trimethylphosphonium, triphenyl Sulfonium, triphenyloxonium, triethyloxonium, pyrylium and the like can be mentioned.

Y is an anionic component of an ionic compound, and examples thereof include an organic boron compound anion, an organic aluminum compound anion, an organic gallium compound anion, an organic phosphorus compound anion, an organic arsenic compound anion, and an organic antimony compound anion. Specifically, tetraphenylboron, tetrakis (pentafluorophenyl) boron, tetraphenylaluminum, tetrakis (pentafluorophenyl) aluminum, tetraphenylgallium, tetrakis (pentafluorophenyl)
Gallium, hexafluorophosphine, hexafluoroarsenic,
Hexafluoroantimony and the like can be mentioned.

Among the electrophilic compounds known as Lewis acid compounds, those which react with a reaction product of a transition metal compound and an organometallic compound to form a polymerization active species, and include various metal halides Examples include compounds and metal oxides known as solid acids. Specific examples include inorganic oxides such as magnesium halide and manganese halide, alumina and magnesium silicate, and oxides that form an interlayer compound such as smectite.

In the present invention, the transition metal compound needs to be brought into contact with the organometallic compound in advance. Further, as a solvent for dissolving the transition metal compound, an aromatic hydrocarbon compound having 1 to 20 carbon atoms or a halogenated hydrocarbon compound, specifically, benzene, toluene, ethylbenzene,
Examples thereof include xylene, cumene, cymene, or those obtained by partially replacing hydrogen with a halogen element, methylene dichloride, chloroform, ethylene dichloride, and trichloroethane.

The compound which reacts with the reaction product of the transition metal compound (a) and the organometallic compound (b) to form a stable anion is preferably added after bringing the catalyst component into contact with the organometallic compound. As the organometallic compound used in the present invention, a metal compound 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 an alkyl group. For example, an alkyl metal compound in which 1 to n alkyl groups having 1 to 12 carbon atoms are bonded, an alkyl metal halide, an alkyl metal alkoxide, or the like can be used. Among them, alkyl aluminum compounds are preferably used, for example, trimethyl aluminum, triethyl aluminum, triisopropyl aluminum, tributyl aluminum, dimethyl aluminum chloride, diethyl aluminum chloride, diisopropyl aluminum chloride, diisopropyl aluminum isopropoxide, ethyl aluminum dichloride,
Ethyl aluminum 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
It is molar 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.

In the present invention, the polymerization method of the olefin is not particularly limited, and various known methods can be employed. Examples thereof include a solvent polymerization method using an inert hydrocarbon as a medium, a bulk polymerization method using a liquid olefin as a medium, and a liquid polymerization method. Any method of gas phase polymerization in which the medium is substantially absent can be employed.

In general, the polymerization is carried out at a temperature of -20 to 150 ° C. and a pressure of normal pressure to 100 kg / cm ^{2. In} addition to homopolymerization of olefins, random or block copolymerization with each other or with ethylene. This polymerization method can be preferably employed.

In addition, two or more reaction tanks can be connected for continuous polymerization. At that time, the hydrogen concentration in each tank can be changed to produce a polymer having a wider molecular weight distribution.
Further, it is possible to give a polyolefin with high activity per solid catalyst even under relatively low hydrogen concentration conditions.

[0032]

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

Example 1 An autoclave having an internal volume of 5 liters and sufficiently dried and replaced with nitrogen was prepared, and 0.2 ml of triethylaluminum and 1 mg of isopropylidene (cyclopentadienyl, fluorenyl) zirconium dichloride as a zirconium compound were added to 100 ml of toluene. Thereafter, the mixture was inserted into an autoclave, and 1.5 kg of propylene, 6.4 mg of triphenylmethyltetrakis (pentafluorophenyl) borane and 6.8 mg of triphenylmethyltetrakis (pentafluorophenyl) aluminum were added thereto, and polymerized at 60 ° C. for 2 hours. After polymerization, unreacted propylene was purged, dried at 80 ° C. for 8 hours, and weighed to obtain 219.8 g of polypropylene.

The intrinsic viscosity (hereinafter abbreviated as η) of 1.33 measured in a tetralin solution of polypropylene at 135 ° C. is 1.33, and 1,2,4-
The ratio of the weight average molecular weight to the number average molecular weight measured using trichlorobenzene as a solvent (hereinafter abbreviated as MW / MN) was 5.4.

Comparative Example 1 The procedure of Example 1 was repeated except that only triphenylmethyltetrakis (pentafluorophenyl) borane was used in the polymerization to obtain 250 g of a polymer. The η of this polymer is
1.60 and MW / MN were 2.0.

Example 2 The procedure of Example 1 was repeated except that dimethylsilylbis (2,4-dimethylcyclopentadienyl) zirconium dichloride was used instead of isopropylidene (cyclopentadienyl, fluorenyl) zirconium dichloride as the zirconium compound. As a result, 380 g of a polymer was obtained. Η of this polymer was 1.02, and MW / MN was 5.8.

Example 3 175 g of a polymer was obtained in the same manner as in Example 1 except that 7.0 mg of triphenylmethyltetrakis (pentafluorophenyl) gallium was used instead of aluminum triphenylmethyltetrakis (pentafluorophenyl). Η of this polymer was 1.8 and MW / MN was 5.8.

[0038]

According to the present invention, a highly stereoregular polyolefin having a relatively wide molecular weight distribution can be produced by carrying out the method of the present invention, which is industrially valuable.

[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-3-203914 (JP, A) JP-A-4-328110 (JP, A) JP-T1-501950 (JP, A) JP-T-5 505838 (JP, A) International Publication 92/1723 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 4/60-4/70

Claims (1)

(57) [Claims] A) a) a compound represented by the following general formula 1 or 2
And B or A 'and B' are the same or different 1
A ligand containing a nitrogen atom, an oxygen atom, a silicon atom, a phosphorus atom or a sulfur atom bonded to a divalent or divalent unsaturated hydrocarbon residue or M, R is a divalent nitrogen atom, an oxygen atom,
A residue containing a silicon atom, a phosphorus atom or a sulfur atom, or a straight-chain saturated hydrocarbon residue which may have a side chain, or a part or all of the straight-chain carbon atoms of which are a silicon atom, a germanium atom or a tin atom And M is a metal atom selected from Group 4 of the periodic table, and X is a halogen atom, a carbon atom, a nitrogen atom, an oxygen atom,
A transition metal compound represented by a ligand containing a silicon atom, a phosphorus atom or a sulfur atom) Embedded image b) gold selected from aluminum, zinc and magnesium
After reacting with the organometallic compound of the genus, c) using the transition metal compound (a) and organometallic compound (b) a compound capable of reacting with a stable anion reaction product of at least two or more polymerizing olefins A method for producing a polyolefin having a wide molecular weight distribution.