JP2002053610A - Catalyst and polymerization of conjugated diene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new catalyst including a Group 5 transition metal compound and a conjugated diene polymerization process that uses the new catalyst and produces conjugated diene polymer having well-controlled microstructure in high activity. SOLUTION: The objective polymerization catalyst comprises a combination of (1) a Group 5 transition metal compound of zero oxidation number bearing a ligand of cycloalkadienyl group with (2) at least one of cocatalyst selected from organoaluminum, organoaluminoxane compound, ionic compound and Lewis acid compound. This invention further provides a polymerization process in which the resultant catalyst is characteristically used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst having a novel transition metal compound of Group V of the Periodic Table, a polymerization catalyst for a conjugated diene using the catalyst, and a polymerization method.

[0002]

2. Description of the Related Art Transition metal metallocene compounds such as Ti, Zr, V and Ni are known as polymerization catalysts for conjugated dienes such as butadiene and isoprene. Regarding Ti, cyclopentadienyltitanium trichloride [CpTiCl ₃ ] has been studied in detail, and the results of research by Ricci and Porri have been reported (Macromolecular Symposia, 1995, Vol. 89,
383). The polymer structure is greatly affected by the type of the diene monomer and the polymerization temperature. In the case of polybutadiene, the cis structure is mainly used. In 1,3-pentadiene, the cis and 1,2 structures are contained in substantially equal amounts. Further, when the polymerization temperature is as low as -30 ° C or lower, most of the 1,2 structure is present. In any case, the polymerization activity of the conjugated diene in this system is not yet sufficient.

[0003] Butadiene polymerization catalyzed by Cp ₂ Ni, Cp ₂ TiCl ₂ , and Cp ₂ ZrCl ₂ is reported in the Journal of Polymers, 1974, Vol. 31, p. 759. Obtained, but with low activity. Japanese Patent Publication No. 46-20494 discloses a catalyst system of CpVCl ₃ and an organoaluminum halide, but has a low activity. Further, as diene polymerization using a metallocene catalyst system belonging to Group 5 of the periodic table, Polymer, 1996, Vol. 37, No. 2, p.
₂ (PEt ₃ ) ₂ and methylalumoxane, and combinations of Cp ₂ VCl and methylalumoxane are disclosed.

JP-A-64-66216, JP-T-63-501962,
JP-A-1-501633 discloses a metallocene compound of V,
A catalyst system for copolymerizing olefins and dienes with a combination of Cp ₂ VCl ₂ and alumoxane is disclosed, but there is no description in the examples, and the performance is unknown. Japanese Unexamined Patent Publication (Kokai) No. 7-509016 discloses a combined catalyst system of an imide, a V, Ta metallocene having a carborane ligand and an ionizing agent, but does not disclose the polymerization performance of a conjugated diene. Therefore, it is unclear what conjugated diene polymer can be obtained.

The present inventors have previously shown that metallocene compounds having an oxidation number of +5, +4, +3, +2 and +1 of V, which is a transition metal belonging to Group 5 of the periodic table, are excellent as polymerization catalysts for conjugated dienes. (Japanese Unexamined Patent Publication No. 9-194526)
, JP-A-32409, JP-A-286811, JP-A-11
−302318, 302319).

Heretofore, high impact polystyrene has required polybutadienes having a vinyl content of about 3 to 20% by weight, which have been prepared using butyllithium as a catalyst. However, compared to polybutadiene obtained from a Co-based catalyst, there are disadvantages such as a low content of a cis structure and a high viscosity due to almost no branched chains. Therefore, a catalyst system consisting of phosphate, organoaluminum, water and Co compound, organoaluminum, water, Co dithiocarbamate
A method for producing a polybutadiene having a cis-1,4 structure and a large vinyl content in a catalyst system comprising a compound has been proposed (JP-A-55-129403 and JP-A-59-232106).
issue). In these, the activity is not sufficient, and there is a problem that a gel is formed in each case.

[0007]

SUMMARY OF THE INVENTION A catalyst having a novel transition metal compound of Group V of the Periodic Table, and a conjugated diene having a high activity to produce a conjugated diene polymer having a controlled microstructure using the catalyst. A polymerization catalyst and a polymerization method are provided.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides (1) a transition metal compound belonging to Group 5 of the Periodic Table having a zero-oxidation number having a ligand of a cycloalkadienyl group, (2) an organoaluminum, and an organoaluminum. The present invention relates to a catalyst comprising a combination with at least one cocatalyst selected from an oxy compound, an ionic compound and a Lewis acid compound.

Further, the present invention relates to (1) a transition metal compound belonging to Group 5 of the Periodic Table having a zero-oxidation number having a ligand of a cycloalkadienyl group, and (2) an organoaluminum, an organoaluminumoxy compound or a Lewis acid. A catalyst obtained from at least one cocatalyst selected from the group consisting of compounds and ionic compounds.

Further, the present invention relates to a catalyst characterized in that the above-mentioned catalyst is a conjugated diene polymerization catalyst.

Further, the present invention relates to a method for polymerizing a conjugated diene, comprising using the above-mentioned catalyst.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The catalyst of the present invention comprises (1) a transition metal compound belonging to Group 5 of the Periodic Table having an oxidation number of 0 having a ligand of a cycloalkadienyl group, (2) an organoaluminum, an organoaluminum. It is a catalyst comprising a combination with at least one cocatalyst selected from oxy compounds, ionic compounds and Lewis acid compounds.

Further, the catalyst of the present invention comprises (1) a transition metal compound belonging to Group 5 of the Periodic Table having an oxidation number of 0 having a ligand of a cycloalkadienyl group, (2) an organoaluminum, an organoaluminumoxy compound, A catalyst obtained from at least one cocatalyst selected from the group consisting of a Lewis acidic compound and an ionic compound.

The above catalyst has good solubility in inert hydrocarbon solvents and is easy to handle.

It is preferable that the above-mentioned catalyst is a polymerization catalyst for a conjugated diene.

The present invention can provide a method for polymerizing a conjugated diene, comprising using the above catalyst for the polymerization of a conjugated diene.

The metal of the transition metal compound of Group 5 of the Periodic Table having an oxidation number of 0 having a ligand of the cycloalkadienyl group includes V, Nb or Ta, and preferably V. The cycloalkadienyl group is a cyclopentadienyl group, an indenyl group, a fluorenyl group, a hydrocarbon group having 1 to 20 carbon atoms or a hydrogen group having 1 to 20 carbon atoms.
And those substituted with a hydrocarbon amino group having 1 to 20 carbon atoms. Substituents include methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, t-butyl, hexyl, phenyl, benzyl, trimethylsilyl, etc. And a hydrocarbon group containing a silicon atom.

As ligands other than the cycloalkadienyl group, amines, amides, phosphines, ethers,
It can also have a neutral Lewis base such as a ketone, ester, olefin, diene, aromatic hydrocarbon, alkyne. The Lewis base preferably has no active hydrogen. The transition metal compound of Group 5 of the Periodic Table of the present invention has a high solubility in inert hydrocarbon solvents, and therefore can be used as a solution in polymerization, and the handling of the catalyst is easy.

Specific examples of the transition metal compounds belonging to Group 5 of the Periodic Table having a zero oxidation number and having a cycloalkadienyl group as a ligand include cyclopentadienyl (cycloheptatrienyl) vanadium and cyclopentadienyl. Enyl (methylcycloheptatrienyl) vanadium, cyclopentadienyl (dimethylcycloheptatrienyl) vanadium, cyclopentadienyl (trimethylcycloheptatrienyl) vanadium, cyclopentadienyl (hexamethylcycloheptatrienyl) vanadium, Cyclopentadienyl (heptamethylcycloheptatrienyl) vanadium, cyclopentadienyl (phenylcycloheptatrienyl) vanadium, cyclopentadienyl (diphenylcycloheptatrienyl) vanadium, cyclopentadienyl (tri Phenylcycloheptatrienyl) vanadium, cyclopentadienyl (hexaphenylcycloheptatrienyl) vanadium, cyclopentadienyl (heptaphenylcycloheptatrienyl) vanadium, methylcyclopentadienyl (cycloheptatrienyl) vanadium, 1 , 3-Dimethylcyclopentadienyl (cycloheptatrienyl) vanadium, 1-methyl-3-
Butylcyclopetadienyl (cycloheptatrienyl)
Vanadium, tetramethylcyclopentadienyl (cycloheptatrienyl) vanadium, pentamethylcyclopentadienyl (cycloheptatrienyl) vanadium, trimethylsilylcyclopentadienyl (cycloheptatrienyl) vanadium, 1,2-bis (trimethylsilyl) ) Cyclopentadienyl (cycloheptatrienyl) vanadium, 1,3-bis (trimethylsilyl) cyclopentadienyl (cycloheptatrienyl) vanadium, indenyl (cycloheptatrienyl) vanadium, 2-methylindenyl (cyclohepta) Trienyl) vanadium, 2-trimethylsilylindenyl (cycloheptatrienyl) vanadium, fluorenyl (cycloheptatrienyl) vanadium, cyclopentadienyl (cyclopropenyl) vanadium, Clopentadienyl (methylcyclopropenyl) vanadium, cyclopentadienyl (dimethylcyclopropenyl) vanadium, cyclopentadienyl (trimethylcyclopropenyl) vanadium, cyclopentadienyl (phenylcyclopropenyl) vanadium, cyclopentadienyl (diphenyl) Cyclopropenyl) vanadium, cyclopentadienyl (triphenylcyclopropenyl) vanadium, indenyl (cyclopropenyl) vanadium and the like can be mentioned.

The organic aluminum oxy compound as a promoter in the present invention is a linear or cyclic polymer represented by the general formula (-Al (R) O-) m. R has 1 to 1 carbon atoms
10 hydrocarbon groups, partially halogen atoms and / or RO
Also includes those substituted with a group. m is the degree of polymerization and is 5 or more, preferably 10 or more. Examples of R 1 include a methyl, ethyl, propyl, and isobutyl group, and a methyl group is preferable.

The above-mentioned ionic compound is a compound which is well known in the transition metal group 4 transition metal metallocene polymerization catalyst system as a cocatalyst capable of forming a cationic complex by reacting with a transition metal compound. Non-coordinating tetrakis (pentafluorophenyl) borate, tetrakis (3,5-bistrifluoromethylphenyl) borate, tetrakis (monofluorophenyl) borate, tetrakis (difluorophenyl) borate are bulky and non-coordinating anions constituting the compound. , Tetrakis (tetrafluorophenyl) borate, tetraphenylborate, and aluminates thereof. On the other hand, as the cation of the ionic compound, for example, (alkyl) ₂ N (C ₆ H ₅ ) H
N, N-dialkylanilinium cation having an active proton such as ⁺ , trialkylammonium cation,
Triallyl ammonium cation, triallyl phosphonium cation, trisubstituted carbonium cation such as (C ₆ H ₅ ) ₃ C ⁺ , oxonium cation, sulfonium cation, carborane cation, metallacarborane cation,
Ferrocenium cation having a transition metal, further typical elemental metal, cation of transition metal and their ether,
A cation to which an amine or the like is coordinated can be given.

The above-mentioned Lewis acid compound includes tris (pentafluorophenyl) borane or aluminum, tris (tetrafluorophenyl) borane or aluminum,
Tris (trifluorophenyl) borane or aluminum; tris (difluorophenyl) borane or aluminum; tris (monofluorophenyl) borane or aluminum; triphenylborane;

When an ionic compound or a Lewis acid compound is used as a co-catalyst in the present invention, in order to prevent the poisoning of the transition metal catalyst component by impurities in the polymerization system, the metal of the group 1 to 3 representative element metal of the periodic table is required. Use in combination with a hydride, an organic metal compound, or an organic aluminum oxy compound is preferred. The periodic table Group 1-3 main element metal hydrides, _{e.g., NaH, LiH, CaH 2,} LiAlH 4, NaBH 4
As the organometallic compound, for example, methyl lithium, butyl lithium, phenyl lithium, dibutyl magnesium, trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, trihexyl aluminum, trioctyl aluminum, ethyl magnesium chloride, butyl magnesium chloride, dimethyl aluminum Chloride, diethylaluminum chloride, sesquiethylaluminum chloride, ethylaluminum dichloride, diethylaluminum hydride and sesquiethylaluminum hydride. As the organometallic compound, a trialkylaluminum such as triethylaluminum and triisobutylaluminum is preferable.

The catalyst system described above may be further combined with water. The molar ratio between the hydride of a metal belonging to Group 1 to 3 of the periodic table, the organometallic compound and water is 0.66 to 5, preferably 0.7 to 1.5, and more preferably 0. 0.8 to 1.5.

In the present invention, the transition metal compound and / or
Or at least one cocatalyst selected from organoaluminums, organoaluminum oxy compounds, ionic compounds, and Lewis acid compounds; and hydrides of the main element metals of Groups 1 to 3 of the periodic table and organometallic compounds. Compound,
Alternatively, it can be used by being supported on an organic polymer compound.
JP-A-61-31404, JP-A-61-276805, JP-A-61-108610,
No. 61-296008, JP-T-63-501368, JP-A-1-207303
No., JP-T1-503715, JP-T2-503687, JP-A-2-170805
JP-A-3-502210 and JP-A-3-234710 disclose a method of supporting a porous inorganic compound with a transition metal compound or a transition metal compound and an organic aluminum oxy compound and / or an organic aluminum compound. Are described, and those methods can be adopted. As the inorganic compound as the carrier, inorganic oxides, inorganic chlorides and inorganic hydroxides are preferable, and those containing a small amount of carbonate and sulfate can also be used. Particularly preferred are inorganic oxides, such as silica, alumina, magnesia, titania, zirconia, and calcia. These inorganic oxides have an average particle size of 5 to 150 μ and a specific surface area of 2 to 800 m ² / g
The porous fine particles are preferably used, for example, after being heat-treated at 100 to 800 ° C. The organic polymer compound preferably has an aromatic ring, a substituted aromatic ring, or a functional group such as a hydroxy group, a carboxyl group, an ester group, or a halogen atom in a side chain. Specific examples include ethylene, propylene, α-olefin homopolymer having the functional group by chemical modification of polybutene, etc., α
-Olefin copolymers, acrylic acid, methacrylic acid,
Examples include homopolymers and copolymers of vinyl chloride, vinyl alcohol, styrene, divinylbenzene, and the like, as well as chemically modified products thereof. As these organic polymer compounds, spherical fine particles having an average particle diameter of 5 to 250 μm are used. By supporting the transition metal compound and / or the ionic compound, contamination due to adhesion of the catalyst to the polymerization reactor can be prevented.

The catalyst of the present invention is not particularly limited, but the conjugated diene can be polymerized by the following method. However, the polymerization of a conjugated diene in the present invention also includes a binary or ternary copolymerization with a small amount of a different olefin, a conjugated diene, or a non-conjugated diene. (i) A solution or slurry [M] of a hydrocarbon or halogenated hydrocarbon of a transition metal compound and a solution or slurry [I] of a hydrocarbon or halogenated hydrocarbon of a cocatalyst are brought into contact in advance, and then conjugated. The diene is polymerized. (ii) [N] or [M] is brought into contact with the monomer in advance, and then brought into contact with [I] to carry out polymerization. (iii) After contacting [I] with the monomer in advance, the polymerization is carried out by contacting [N] or [M]. (iv) A solution of a hydrocarbon or halogenated hydrocarbon of a transition metal compound [N] and a solution of a hydrocarbon or halogenated hydrocarbon of an aluminoxane and / or an ionic compound [P] are mixed, and then contacted with a carrier. And polymerized by contacting the monomers. (v) After contacting [N] with the carrier, [P] is contacted to separate the carrier and polymerize the conjugated diene. (vi) After [P] is brought into contact with the carrier, [N] is brought into contact, the carrier is separated, and the conjugated diene is polymerized.

Examples of the hydrocarbon solvent for dissolving and slurrying each component include inert hydrocarbons such as hexane, heptane, octane, cyclohexane, mineral oil, benzene, toluene and xylene, and halogenated hydrocarbon solvents. Examples include chloroform, methylene chloride, dichloroethane, chlorobenzene and the like. The contact of each component is usually performed at 0 to 100 ° C. for 10 to 180 minutes. The molar ratio of the ionic compound or Lewis acid compound / transition metal compound is usually 0.01 to 100,
Preferably it is 0.1-10. When the co-catalyst is an ionic compound or a Lewis acid compound, the amount of the organometallic compound preferably used together is usually a molar ratio of organometallic compound / transition metal compound of from 10 to 10,000, preferably from 20 to 300. When the promoter is an organic aluminum oxy compound,
The molar ratio of the organoaluminum oxy compound (Al) / transition metal compound is usually 10 to 10,000, preferably 50 to 3,000. The molecular weight of the polymer can be controlled by hydrogen as a chain transfer agent, polymerization temperature, catalyst concentration, and monomer concentration.

The catalyst and polymerization method in the present invention may be any of a fluidized method using a supported catalyst, a stirred gas phase method, a slurry method in an inert hydrocarbon solvent, and a solution method in an inert hydrocarbon solvent. It can also be used for the polymerization method. The polymerization conditions are usually a temperature of 5 to 110 ° C, a time of 10 to 360 minutes, and a pressure of normal pressure to 50 kg /
done in cm2. Examples of the inert hydrocarbon solvent include butane, butene, pentane, pentene, hexane, hexene, heptane, octane, cyclohexane, mineral oil, benzene, toluene, xylene and the like.

Specific examples of the conjugated diene in the present invention include:
Butadiene, isoprene, 2,3-dimethylbutadiene, 1,
Examples include 3-pentadiene, 2-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene, and 2,4-hexadiene. In the present invention, copolymerization of a conjugated diene and a small amount of an olefin is also included. Specific examples of olefins that can be used for copolymerization with a conjugated diene include ethylene, propylene, 1-
Butene, 4-methyl 1-pentene, 1-hexene, 1-octene, norbornene, cyclopentene, trimethylvinylsilane, non-conjugated dienes include dicyclopentadiene, 5-ethylidene-2-norbornene, and 1,5-hexadiene Can be.

When a conjugated diene is polymerized using the catalyst of the present invention and a polymerization method using the catalyst, the microstructure of the resulting diene polymer is controlled, and the content of the cis structure is usually 40% by weight. % Or more, preferably 80% by weight
The content is particularly preferably at least 85% by weight. The content of the vinyl structure is usually at least 3% by weight, preferably at least 5% by weight, particularly preferably at least 7% by weight. The resulting diene polymer can be usefully used as a diene polymer for producing high-impact polystyrene.

[0031]

The present invention will be described below more specifically with reference to examples and comparative examples. The present invention is not limited to only these examples. Microstructure was performed by infrared absorption spectroscopy. Cis 740 cm-
1. The microstructure was calculated from the absorption intensity ratio of 980 cm-1 of trans and 910 cm-1 of vinyl.

The intrinsic viscosity [η] was measured by the following method, and the value calculated according to the formula (1) was used. The solution drop time of the viscosity measurement was measured using a Canon Fenske viscometer N
o. 75 at 75 ° C. The falling time t (second) of the polymerization solution was precisely measured for 20 mg of the polymer,
The measurement was performed using a solution dissolved in 1 l of toluene. [Η] = {(1 + 4 × k ′ × ηsp) ^1/2 −1} / (2 × k ′ × c) (1) where ηsp = (t / to−1) k ′ = 0.37 (Huggins Constant), t: Fall time of polymer solution (sec), to: Fall time of toluene (sec), c: Solution concentration of polymer (g / dl)

(Synthesis Example 1) [Preparation of Transition Metal Compound] Cyclopentadienyl (cycloheptatrienyl) vanadium was obtained from Journal of Organo
It was synthesized by the method described in Metallic Chemistry, 1974, vol. 71, p. 257. That is, cyclopentadienyl vanadium trichloride was dissolved in diethyl ether at −50 ° C. at −50 ° C. for cycloheptatriene, i.
After reacting with propylmagnesium bromide, the solvent was distilled off, and the residue was sublimated in vacuo to obtain a solid, which was recrystallized from n-hexane to obtain dark purple crystals. Elemental analysis values almost agreed with the theoretical values. 20.7mg of these crystals
Is dissolved in toluene to give 50 ml of a 2 mmol / l solution.
Was prepared.

(Example 1) [Polymerization of 1,3-butadiene] 1 ml (1 mmol) of a 1 mol / l toluene solution of triethyl aluminum was added to 194 ml of a toluene solution of 1,3-butadiene (containing 21.6 g of 1,3-butadiene). And keep the solution at 30 ° C. [Ph ₃
1.5 ml of a 5 mmol / l toluene solution of CB (C ₆ F ₅ ) ₄ ] (7.
5 μmol), 2.5 ml of a 2 mmol / l toluene solution of cyclopentadienyl (cycloheptatrienyl) vanadium
(5 μmol) and polymerization was carried out for 30 minutes. The polymerization was terminated with ethanol containing an antioxidant, filtered and dried to obtain 2.17 g of a white butadiene polymer. The microstructure was cis 89.2%, trans 1.7%, vinyl 9.1%.
[Η] at 30 ° C. in toluene was 9.6.

(Example 2) [Polymerization of 1,3-butadiene] Except that the amount of a 1 mol / l toluene solution of triethylaluminum used in Example 1 was 0.5 ml (0.5 mmol) and the polymerization time was 60 minutes. Was similarly polymerized. The polymerization was terminated with ethanol containing an antioxidant, filtered and dried to obtain 0.67 g of a white butadiene polymer. Micro structure is cis 88.9%, transformer
1.8% and vinyl 9.2%. [Η] in toluene at 30 ° C. was 8.8.

Example 3 [1,3-Butadiene polymerization] Polymerization was carried out in the same manner as in Example 1 except that the amount of a 1 mol / l toluene solution of triethylaluminum was changed to 1.5 ml (1.5 mmol). Was. The polymerization was stopped with an antioxidant-containing ethanol, filtered and dried to obtain 2.2 g of a white butadiene polymer. Microstructure: cis 89.4%, trans 1.3%, vinyl 9.2
%Met. [Η] at 30 ° C. in toluene is 1
0.6.

(Comparative Example 1) [Polymerization of 1,3-butadiene] The procedure of Example 1 was repeated except that 2.0 μmol of vanadium oxytrichloride (VOCl ₃ ) was used instead of cyclopentadienyl (cycloheptatrienyl) vanadium. Polymerization was performed in the same manner. As a result, substantially no polymer was obtained.

[0038]

The catalyst of the present invention has good solubility in hydrocarbon solvents and is easy to handle. The catalyst of the present invention can be used for a conjugated diene polymerization catalyst, a conjugated diene polymerization method, and a conjugated diene polymer production.

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Claims (4)

[Claims] (1) a transition metal compound belonging to Group 5 of the Periodic Table having an oxidation number of 0 and having a ligand of a cycloalkadienyl group;
(2) A catalyst comprising a combination with at least one cocatalyst selected from organic aluminum, organic aluminum oxy compounds, ionic compounds, and Lewis acid compounds. 2. A transition metal compound belonging to Group 5 of the Periodic Table having a zero-oxidation number and having a ligand of a cycloalkadienyl group and (2) an organic aluminum, an organic aluminum oxy compound, a Lewis acidic compound and an ionic compound. A catalyst obtained from at least one cocatalyst selected from the group consisting of compounds. 3. The catalyst according to claim 1, wherein the catalyst is a conjugated diene polymerization catalyst. 4. A method for polymerizing a conjugated diene, comprising using the catalyst according to claim 1.