JPH05230135A - Production of polyolefin with broad molecular weight distribution - Google Patents

Abstract

PURPOSE:To efficiently obtain the subject polymer with high stereoregularity by polymerizing an olefin using at least two kinds of compounds capable of forming a stable anion by reaction with a reaction product from a transition metal compound and an organometallic compound. CONSTITUTION:The objective polyolefin with broad molecular weight distribution can be obtained by polymerizing an olefin using at least two kinds of compounds capable of forming a stable anion by reaction with a reaction product from (A) a transition metal compound of formula I (A and B are each monovalent or divalent unsaturated hydrocarbon residue, or ligand containing N, O, Si, P, or S; X is halogen, or ligand containing C, N, O, Si, P, or S; M is group IV or V metal) or formula II (A' and B' are the same kinds as A and B, respectively; R is divalent residue containing N, O, Si, P, or S, straight chain saturated hydrocarbon residue which may have side chain, or residue with part or all of carbon atoms on the straight chain substituted with Si, Ge or Sn) and (B) an organometallic compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a polyolefin having a wide molecular weight distribution. Specifically, it relates to a method for producing a highly stereoregular polyolefin having a wide molecular weight distribution by combining specific compounds.

[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 also 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, it has been reported that an isolated cationic metallocene compound having cyclopentadiene or a derivative thereof as a ligand has a polymerization activity for an olefin by itself, even in the absence of coexisting methylaluminoxane. Has been done.

For example, RF JORDAN, 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 a ligand has a donor such as tetrahydrofuran as a ligand. It has been reported that the complex thus isolated has a polymerization activity of ethylene 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
It is formed from a transition metal compound having a cyclopentadienyl group having a substituent at 36 or a derivative thereof as a ligand and capable of reacting with a proton, and a compound providing a stable anion having a cation capable of giving a proton. It has been reported that the ion-pair type metallocene complex with olefin polymerization activity. Furthermore, Zambel
li et al., Maclomolecules, 1989, Vol. 22, pp. 2186-2189, propylene is polymerized by a catalyst that combines a zirconium compound having a derivative of a cyclopentadienyl group as a ligand and trimethylaluminum and fluorodimethylaluminum, and isotactic It has been reported that polypropylene can be obtained, and in this case also, the active species is considered to be a metallocene compound in an ion pair form.

[0007]

When polyolefins are produced by polymerizing olefins using a catalyst composed of these transition metal metallocene compounds, in each case, a very narrow polyolefin having a molecular weight distribution of about 2 is produced. However, since polyolefins having various molecular weight distributions are required depending on the field of use of the polyolefins, JP-A-60-35006 and 60-35008 use two or more different metallocene catalysts as a method for broadening the molecular weight distribution. Therefore, a method for producing a polymer having a wide molecular weight distribution is disclosed.

However, it is known that the above catalyst systems differ in the structure of the polymer produced by each catalyst system, 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-olefin such as propylene, the stereoregularity of the polymer obtained by the catalyst is different, and it was extremely difficult to change only the molecular weight distribution.

[0009]

[Means for Solving the Problems] The present inventors completed the present invention by earnestly investigating a method for producing a polymer having a wide molecular weight distribution by solving the above problems. That is, the present invention is
a) the following general formula 3 or 4 (wherein A and B or A ′ and B ′ are the same or different from each other, a monovalent or divalent unsaturated hydrocarbon residue or a nitrogen atom bonded to M, A ligand containing an oxygen atom, a silicon atom, a phosphorus atom or a sulfur atom, R is a divalent nitrogen atom, an oxygen atom, a silicon atom,
A residue containing a phosphorus atom or a sulfur atom, or a linear saturated hydrocarbon residue which may have a side chain, or a part or all of the carbon atoms of the straight chain thereof is substituted with a silicon atom, a germanium atom or a tin atom. , M is a metal atom selected from Group 4 or 5 of the periodic table, and X is a halogen atom, a carbon atom, a nitrogen atom, an oxygen atom, a silicon atom, a phosphorus atom or a bond with M. A ligand containing a sulfur atom) represented by a transition metal compound,

[0010]

[Chemical 3]

[0011]

[Chemical 4] b) a molecular weight characterized by polymerizing an olefin by using at least two kinds of compounds which, after reacting with an organometallic compound, c) react with a reaction product of a transition metal compound and an organometallic compound to form a stable anion. This is a method for producing a polyolefin having a wide distribution.

In the present invention, the transition metal compound is
The transition metal compound represented by the chemical formula 3 or 4 of the above general formula can be exemplified.

In Formula 3 or Formula 4 of the above general formula,
Examples of the unsaturated hydrocarbon residue represented by A, B, A ′ or B ′ include groups having a monocyclic or polycyclic conjugated π electron having 5 to 50 carbon atoms, and specific examples include cyclo 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 end is again bound to the cyclopentadiene ring) Or a polycyclic aromatic hydrocarbon residue such as indenyl or fluorenyl, or a part or all of the hydrogen thereof has 1 to 10 carbon atoms.
Those substituted with the hydrocarbon residue of

Furthermore, 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 some of them are substituted with a hetero atom) And a ligand bonded to the transition metal atom M represented by Here, R'of A'and B'has a structure crosslinked by R.

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 formula 5 or a silylene group in which some or all of carbon atoms of the methylene group are substituted with silicon atoms, germanium atoms, or tin atoms, Examples thereof include germylene groups and stannylene groups.

[0016]

[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 be 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 replaced with a hetero atom).

Further, as the compound which reacts with the reaction product of the transition metal compound and the organometallic compound to form a stable anion,
An ionic compound or an electrophilic compound formed from an ion pair of a cation and an anion, which reacts with a reaction product of a transition metal compound and an organometallic compound to form a polymerization active species. Among these, the ionic compound is represented by the following formula 6.

[0019]

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

In Formula 6, 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 triphenylcarbonium, diphenylcarbonium, cycloheptatrienium, tributylammonium, N, N-dimethylanilinium, dipropylammonium, dicyclohexylammonium, triphenylphosphonium, trimethylphosphonium and triphenyl. Examples thereof include sulfonium, triphenyloxonium, triethyloxonium and pyrylium.

Y is an anion 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, hexafluorophosphorus, hexafluoroarsenic,
Hexafluoroantimony and the like can be mentioned.

Further, as the electrophilic compound, among the compounds known as Lewis acid compounds, compounds which react with a reaction product of a transition metal compound and an organometallic compound to form a polymerization active species, and various metal halides are used. Examples thereof include compounds and metal oxides known as solid acids. Specific examples include magnesium halides, manganese halides, inorganic oxides such as alumina and magnesium silicate, and oxides forming an intercalation compound such as smectite.

In the present invention, the transition metal compound needs to be contacted with the organometallic compound in advance. Further, as the 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 substituting a part of hydrogen with a halogen element, methylene dichloride, chloroform, ethylene dichloride, trichloroethane and the like.

The compound which reacts with the reaction product of the transition metal compound and the organometallic compound to form a stable anion is preferably added after the catalyst component is brought into contact with the organometallic compound. As the organometallic compound used in the present invention, a compound of a metal selected from aluminum, zinc and magnesium is used. These organometallic compounds have residues of halogen, oxygen, hydrogen, alkyl, alkoxy, aryl, etc. 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 having an alkyl residue having 1 to 12 carbon atoms bonded to 1 to n, an alkyl metal halide, an alkyl metal alkoxide and the like can be used. Alkyl aluminum compounds are preferably used among them, 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 dichloride. Examples include isopropoxide and the like.

The ratio of the organometallic compound to the above transition metal compound is 1 to 100,000 mole times, usually 1 to 5000.
It is mole times.

The solvent used in the preparation, polymerization or treatment of the catalyst using the catalyst component of 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. Further, an ether, a nitrile, an ester compound or the like can be used as long as the solvent itself does not bind to the produced transition metal cation compound or strongly coordinate to inactivate the polymerization activity.

The olefin polymerization conditions using this catalyst component 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 also be used.

Examples of the olefins used for the polymerization include olefins having 2 to 25 carbon atoms, specifically, 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
In addition to 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 and norbornene are exemplified, and these can be used for homopolymerization or mutual copolymerization, and, if necessary, copolymerization with dienes and the like.

In the present invention, the olefin polymerization method is not particularly limited, and various known methods can be employed, including 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 of the gas phase polymerization methods in which the medium is substantially absent can be adopted.

The polymerization is generally 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. The present polymerization method can be preferably adopted.

Further, two or more reaction tanks may be connected to carry out continuous polymerization, in which case the hydrogen concentration in each tank may be varied 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 a condition of relatively low hydrogen concentration.

[0032]

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

Example 1 A fully dried autoclave having an internal volume of 5 liters and purged 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. Then, the mixture was placed in 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, and polymerization was carried out at 60 ° C. for 2 hours. After the 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) measured with a 135 ° C. tetralin solution of polypropylene is 1.33, and 1,2,4-at 135 ° C. by gel permeation chromatography.
The ratio of the weight average molecular weight to the number average molecular weight (hereinafter abbreviated as MW / MN) measured using trichlorobenzene as a solvent was 5.4.

Comparative Example 1 250 g of a polymer was obtained in the same manner as in Example 1 except that only triphenylmethyltetrakis (pentafluorophenyl) borane was used in the polymerization. Η of this polymer is
It was 1.60 and MW / MN was 2.0.

Example 2 As in Example 1, except that dimethylsilylbis (2,4-dimethylcyclopentadienyl) zirconium dichloride was used instead of isopropylidene (cyclopentadienyl, fluorenyl) zirconium dichloride as the zirconium compound. Then, 380 g of a polymer was obtained. This polymer had an η of 1.02 and a MW / MN of 5.8.

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

[0038]

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

[Brief description of drawings]

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

Claims (1)

[Claims] 1. A) The following general formula 1 or formula 2 (wherein A is
And B or A ′ and B ′ are the same or different from each other 1
A valent or divalent unsaturated hydrocarbon residue or a ligand containing a nitrogen atom, an oxygen atom, a silicon atom, a phosphorus atom or a sulfur atom bonded to 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 linear saturated hydrocarbon residue which may have a side chain, or a part or all of the carbon atoms in the straight chain thereof is a silicon atom, a germanium atom or a tin atom. , M is a metal atom selected from Group 4 or 5 of the periodic table, and X is a halogen atom, a carbon atom, a nitrogen atom, an oxygen atom, a silicon atom bonded to M, A transition metal compound represented by a ligand containing a phosphorus atom or a sulfur atom) [Chemical 2] b) a molecular weight characterized by polymerizing an olefin by using at least two kinds of compounds which, after reacting with an organometallic compound, c) react with a reaction product of a transition metal compound and an organometallic compound to form a stable anion. A method for producing a polyolefin having a wide distribution.