JP2001122920A - Butadiene polymer and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a butadiene polymer having a narrow molecular weight and a high 1,4-cis bond content and to provide a method for producing the butadiene polymer. SOLUTION: This butadiene polymer having <=1.5 Mw/Mn and >=96 mol% 1,4-cis bond content is obtained by polymerization at a specific polymerization temperature by using a catalyst obtained by previously preparing a transition metal compound (A) of the group IV of the periodic table having a cyclopentadienyl skeleton containing an ether group-containing substituent and at least one kind of a cocatalyst selected from an organoaluminum oxy- compound (B1), an ionic compound (B2), a Lewis acid (B3) and an organometallic compound composed of a metal of the groups I to III of the periodic table under specific aging conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butadiene polymer and a method for producing the same, and more particularly to a butadiene polymer having a narrow molecular weight distribution and a high 1,4-cis bond content, and a specific polymer prepared under specific ripening conditions. The present invention relates to a method for producing the butadiene polymer, which comprises polymerizing at a specific polymerization temperature using a metallocene polymerization catalyst having a structure.

[0002]

2. Description of the Related Art Butadiene polymers are widely used as rubbers having excellent properties. In particular, various studies have been made on a butadiene polymer having a high 1,4-cis bond content, since the vulcanized rubber is excellent in mechanical strength and the like. Butadiene polymers having a 1,4-cis bond content of 90% or more have been produced using typical coordination polymerization catalysts using cobalt, nickel, titanium, and neodymium as polymerization catalyst metals. However, those butadiene polymers have a broad molecular weight distribution. On the other hand, when an organolithium polymerization catalyst is used, living polymerization of butadiene proceeds, and a butadiene polymer having a high molecular weight and a narrow molecular weight distribution is obtained, but its cis bond content is low.

[0003] Recently, studies have been made to apply a metallocene polymerization catalyst having characteristics such as high activity and excellent control of tacticity of a polymer to rubber production. JP-A-9-77818 proposes a conjugated diene polymerization catalyst comprising a combination of a transition metal compound belonging to Group IV of the periodic table represented by the following general formula 1 and aluminoxane. By polymerizing butadiene with this polymerization catalyst, a polymer having a 1,4-cis bond content of 96% is obtained.

[0004]

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Wherein M is a transition metal of Group IV of the periodic table,
X is a hydrogen atom, halogen, a hydrocarbon group having 1 to 12 carbon atoms, or a hydrocarbonoxy group having 1 to 12 carbon atoms, and Y is a hydrocarbon group having 1 to 20 carbon atoms, which is itself a cyclopentadienyl group. And Z may form a ring, and Z is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. The structure in which a circle is drawn in the pentagon in the general formula 1 represents a cyclopentadiene ring structure. )

Further, application of a metallocene polymerization catalyst comprising a transition metal compound belonging to Group IV of the periodic table represented by the following structural formula 1 to butadiene polymerization has been disclosed (industrial science and technology first R & D). Proc. Of Technical Symposium for Creating Highly Functional Materials, December 10, 1997, p. 77). Structural formula 1: CH ₃ O (CO) CH ₂ CpTiCl ₃ (In the formula, Cp represents a cyclopentadiene ring structure.) This polymerization catalyst is highly active, and the polybutadiene obtained has a high 1,4-cis bond content. Also, the molecular weight distribution is somewhat narrower than the high cis butadiene polymer obtained with conventional typical coordination polymerization catalysts.

[0007] In addition, the proceedings of the 76th Annual Meeting of the Chemical Society of Japan (2H105, Yokohama (1999)) include a 98.8 mol 1,4-cis bond content obtained using samarium as a catalyst metal. %, Mw / Mn is 1.82, Mn
Is 401,000 (in terms of standard polystyrene).

As described above, studies have been made to produce butadiene polymers having a narrow molecular weight distribution and a high 1,4-cis bond content using various metallocene polymerization catalysts. There is no known butadiene polymer that satisfies the high level requirements in both the 1,4-cis bond content.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a butadiene polymer having a very narrow molecular weight distribution and a very high 1,4-cis bond content, and a method for producing the same.

[0010]

Thus, according to the present invention, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.5 or less and Mn is 30,000.
Butadiene polymers having a 1,4-cis bond content of at least 96 mol%. According to the present invention, there is provided a periodic table IV having a cyclopentadienyl skeleton having a substituent having an ether group.
Group transition metal compound (A), organic aluminum oxy compound (B1), ionic compound (B2), Lewis acid (B
3) and at least one cocatalyst selected from organometallic compounds (B4) consisting of metals from Groups I to III of the periodic table, which are previously contacted and aged under conditions satisfying the following formulas α and β. A method for producing the butadiene polymer, characterized in that 1,3-butadiene is polymerized at 0 ° C. or lower in the presence of a catalyst. Formula α: 0 ≦ T ≦ 50 Formula β: 0.5 ≦ t ≦ 2000exp (−0.0921
T) Here, T is a contact temperature (° C.), and t is a contact time (minute).

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION (Butadiene polymer) The butadiene polymer of the present invention has a weight average molecular weight (Mw) to number average molecular weight (Mn) ratio (Mw / Mn) of 1.5 or less.
Is 30,000 to 3,000,000, and the 1,4-cis bond content is 96 mol% or more. Mw / Mn in the butadiene polymer of the present invention is 1.5 or less, preferably 1.4 or less, more preferably 1.2 or less. When the value of Mw / Mn is large, abrasion resistance and the like when vulcanized rubber are formed are reduced. However, since it is difficult to produce a polymer having Mw / Mn less than about 1.1,
A polymer having Mw / Mn of about 1.1 or more is practically useful.

The Mn of the butadiene polymer of the present invention is 3
0000-3,000,000, preferably 50,000
00 to 2,000,000, more preferably 100,0
00 to 1,000,000. When Mn is low,
When vulcanized rubber is used, the mechanical strength and the like decrease, and when it is high, processability decreases. The lower limit of the 1,4-cis bond content in the butadiene polymer of the present invention is 96 mol%, preferably 97 mol%, based on all butadiene bond units in the polymer.
Mol%, more preferably 98.5 mol%. The higher this content is, the more the mechanical strength of the vulcanized rubber becomes.

(Method for Producing Butadiene Polymer) The butadiene polymer of the present invention comprises a transition metal compound (A) belonging to Group IV of the periodic table having a cyclopentadienyl skeleton having a substituent having an ether group, and an organoaluminum. Oxy compound (B1), ionic compound (B2), Lewis acid (B3)
And at least one co-catalyst selected from organometallic compounds (B4) consisting of metals from Groups I to III of the Periodic Table and previously contacted and aged under conditions satisfying the following formulas α and β for polymerization: It is obtained by polymerizing 1,3-butadiene at 0 ° C. or lower in the presence of a catalyst. Formula α: 0 ≦ T ≦ 50 Formula β: 0.5 ≦ t ≦ 2000exp (−0.0921
T) Here, T is a contact temperature (° C.), and t is a contact time (minute).

Transition metal compound (A) The transition metal compound (A) used in the present invention, which has a cyclopentadienyl skeleton having a substituent having an ether group, preferably has the following general formula 2 Is a transition metal compound belonging to Group IV of the Periodic Table.

[0015]

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(Wherein L is a compound having a cyclopentadiene ring structure, M is a transition metal of Group IV of the periodic table, E is a hydrogen atom, a halogen, a hydrocarbon group having 1 to 12 carbon atoms, and a carbon group having 1 to 12 carbon atoms. Or a hydrocarbon oxy group of 1 to 1 carbon atoms
2 is an amino group substituted with a hydrocarbon group. Multiple E
May be the same or different, and a part of E and a cyclopentadiene ring may combine to form a cyclic structure. n is 2 or 3. Q is an organic group on the cyclopentadiene ring, and at least one of Q has an ether group. m is an integer of 1 to 5. )

That is, the transition metal compound (A) represented by the general formula 2 is a so-called half having only one cyclopentadiene or a condensed ring compound having a cyclopentadiene ring structure such as indene or fluorene as a ligand. A metallocene compound having at least one substituent having an ether group on the cyclopentadiene ring of the ligand.

Group IV transition metal of the periodic table (M in the formula)
Is preferably titanium, zirconium or hafnium, and more preferably titanium. Among those represented by E, halogens include a fluorine atom, a chlorine atom,
A bromine atom and an iodine atom are mentioned, and a chlorine atom is preferable. Examples of the hydrocarbon group include an alkyl group having 1 to 12 carbon atoms such as methyl, ethyl, isopropyl, butyl and neopentyl, and an aralkyl group having 7 to 12 carbon atoms such as benzyl. Examples of the hydrocarbonoxy group include an alkoxy group having 1 to 12 carbon atoms such as methoxy, ethoxy, and isopropoxy, and an aralkyloxy group having 7 to 12 carbon atoms such as benzyloxy.

Examples of the amino group substituted with a hydrocarbon group having 1 to 12 carbon atoms include dimethylamino, diethylamino,
Examples thereof include dialkylamino groups having an alkyl group having 1 to 12 carbon atoms, such as diisopropylamino, dibutylamino, and di-t-butylamino. These carbon atoms constituting E may be substituted by silicon atoms.
E may be bonded to a cyclopentadiene ring to form a cyclic structure. In this case, the transition metal compound (A)
A so-called geometrically constrained catalyst having a metallocycle structure. When E is bonded to the cyclopentadiene ring, it may be via an oxygen atom, a sulfur atom, a nitrogen atom or the like. n is an integer of 2 or 3, and is preferably 3.

Q is an organic group on the cyclopentadiene ring, and at least one of Q has an ether group. m is an integer of 1 to 5. When m is 2 or more, Q may be the same or different from each other. The preferred integer m is 1. As the organic group Q having an ether group, the carbon group 2
To 12 alkoxyalkyl groups, C7 to C20 aryloxyalkyl groups, C1 to C12 alkoxy groups, C6 to C14 aryloxy groups, C7 to C1
2 aralkyloxy groups and the like. The hydrogen in the alkoxy group may be further substituted with an alkoxy group, an aryloxy group, or the like.

Examples of the alkoxyalkyl group include methoxymethyl, methoxyethyl, ethoxyethyl, t-butoxyethyl, (2-methoxyethoxy) ethyl and the like. Examples of the aryloxyalkyl group include phenoxymethyl, phenoxyethyl and the like. Examples of the alkoxy group include methoxy, ethoxy, t-butoxy and the like. Examples of the aryloxy group include phenoxy and the like. Examples of the aralkyloxy group include benzyloxy and the like. Among these, an alkoxyalkyl group is preferable, and among them, an alkoxyethyl group such as methoxyethyl, ethoxyethyl, and t-butoxyethyl is more preferable.

Other organic groups Q include those having 1 to 2 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, hexyl, octyl and cyclohexyl.
0 alkyl groups, aralkyl groups having 7 to 20 carbon atoms such as benzyl and triphenylmethyl. Other organic groups Q include a trimethylsilyl group,
Such as trimethylstannyl group and trimethylgermyl group,
In addition to organic metal groups consisting of hydrocarbon groups having 1 to 6 carbon atoms and silicon, tin or germanium, thioether groups, carbonyl groups, sulfonyl groups, ester groups, thioester groups, amino groups, alkyl-substituted amino groups, amide groups, etc. And the like.

The specific compound of the transition metal compound (A) is not particularly limited, but for example, the following (1) to (1)
And (5). (1) Substituted cyclopentadienyl titanium tri (or di) halide Specific examples include (2-methoxyethyl) cyclopentadienyl titanium tri (or di) chloride, (2
-Ethoxyethyl) cyclopentadienyltitanium tri (or di) bromide, [2- (t-butoxy) ethyl] cyclopentadienyltitanium tri (or di) chloride, phenoxyethylcyclopentadienyltitanium tri (or di) Chloride, 2- (2-
Methoxyethoxy) ethylcyclopentadienyltitanium tri (or di) chloride (1-t-butyl)
[3- (2-methoxyethyl)] cyclopentadienyltitanium tri (or di) chloride, (1,2-dimethyl) [4- (2-methoxyethyl)] cyclopentadienyltitanium tri (or di) chloride ,
(1,2,4-trimethyl) [3- (2-methoxyethyl)] cyclopentadienyltitanium tri (or di) chloride, (tetramethyl) (2-methoxyethyl) cyclopentadienyltitanium tri (or di) )
Chloride and the like. Among them, (2-methoxyethyl) cyclopentadienyltitanium trichloride, [2- (t-butoxy) ethyl] cyclopentadienyltitanium trichloride, (1-t-butyl)
[3- (2-methoxyethyl)] cyclopentadienyltitanium trichloride is preferred.

(2) Indenyl titanium tri (or di) halide having a substituent on the cyclopentadiene ring Specific examples include [1- (2-methoxyethyl)] indenyl titanium tri (or di) chloride, [ 1-
(2-methoxyethyl)] (3-methyl) indenyl titanium tri (or di) chloride, [1- (2-methoxyethyl)] (2,3-dimethyl) indenyl titanium tri (or di) chloride and the like. No.

(3) Fluorenyl titanium tri (or di) halide having a substituent on the cyclopentadiene ring. Specific examples include [9- (2-methoxyethyl)] fluorenyl titanium tri (or di) chloride. And the like.

(4) Compounds in which all or a part of the halogen atoms bonded to the central metal of the compounds of (1) to (3) are substituted with a hydrocarbon group or a hydrocarbonoxy group. Methoxyethyl) cyclopentadienyltitanium tri (or di) benzyl, (2-
Methoxyethyl) cyclopentadienyltitanium tri (or di) butoxide and the like.

(5) Compound in which titanium, which is the central metal of the compounds of (1) to (4), is replaced with zirconium or hafnium. Specific examples include (2-methoxyethyl) cyclopentadienyl zirconium tri (or di). Chloride,
(2-methoxyethyl) cyclopentadienyl hafnium tri (or di) chloride [1- (2-methoxyethyl)] indenyl zirconium tri (or di) chloride. As the transition metal compound (A), a compound having the structure (1) is preferable among the compounds (1) to (5).

Organic aluminum oxy compound (B1) The organic aluminum oxy compound (B1) used in the present invention
1) is a compound having a structure represented by the following general formula 3 or 4.

[0029]

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[0030]

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(Wherein, R _{1 to} R ₆ are each a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms or a hydrocarbon oxy group having 1 to 10 carbon atoms. S is 0 or more. It is an integer, preferably 5 or more, and the upper limit is preferably 100, more preferably 50. Also, R _{1 to} R ₆
May be the same or different. )

Examples of the halogen atom in the general formulas 3 and 4 include a fluorine atom, a bromine atom, a chlorine atom and an iodine atom. Among them, a chlorine atom is preferable. Examples of the hydrocarbon group in the general formulas 3 and 4 include a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, and a phenyl group. Among them, a methyl group, an ethyl group, a propyl group, and a butyl group are preferable. Examples of the hydrocarbon oxy group in the general formulas 3 and 4 include a methoxy group, an ethoxy group, and a butoxy group.

Specific examples of the organic aluminum oxy compound (B1) include methylaluminoxane, ethylaluminoxane, propylaluminoxane, butylaluminoxane, chloroaluminoxane and the like. Among them, methylaluminoxane is preferred.

Organic aluminum oxy compound (B1)
Can be synthesized by reacting an organoaluminum metal compound with water. Examples of the organic aluminum metal compound include, for example, trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, diethylaluminum hydride, dimethylaluminum chloride, diethylaluminum chloride, methylaluminum sesquichloride, ethylaluminum sesquichloride, methylaluminum dichloride, ethyl Aluminum dichloride and the like can be mentioned. Mixtures of these can also be used.

Ionic Compound (B2) The ionic compound (B2) used in the present invention is a compound capable of reacting with the transition metal compound (A) to form a cationic transition metal compound. It is an ionic compound composed of a cation. The non-coordinating anion is not particularly limited, and examples include an organic boron compound anion.

The organic boron compound anions include tetra (phenyl) borate and tetra (fluorophenyl)
Borate, tetrakis (difluorophenyl) borate, tetrakis (trifluorophenyl) borate, tetrakis (tetrafluorophenyl) borate, tetrakis (pentafluorophenyl) borate, tetrakis (tetrafluoromethylphenyl) borate, tetra (triyl) borate, tetra ( Xylyl) borate,
(Triphenylpentafluorophenyl) borate,
[Tris (pentafluorophenyl) phenyl] borate and the like.

The cation is not particularly limited.
For example, a carbonium ion, an oxonium ion, an ammonium ion, a phosphonium ion, and a ferrocenium ion can be given. As carbonium ions,
Triphenylcarbonium ion, tri (methylphenyl) carbonium ion, tri (dimethylphenyl) carbonium ion and the like. Examples of the oxonium ion include a methyloxonium ion, a dimethyloxonium ion, and a trimethyloxonium ion.

As the ammonium ion, trimethylammonium ion, triethylammonium ion,
Trialkyl ammonium ions such as tripropyl ammonium ion and tributyl ammonium ion;
Dialkylammonium ions such as diisopropylammonium ion and dicyclohexylammonium ion; N, N-diethylanilinium ion and N, N-
N, N-dialkylanilinium ions such as dimethyl-2,4,6-trimethylanilinium ion; and the like. Examples of the phosphonium ion include a triphenylphosphonium ion, a tri (methylphenyl) phosphonium ion, and a tri (dimethylphenyl) phosphonium ion. Examples of the ferrocenium ion include a 1,1′-dimethylferrocenium ion.

The ionic compound (B2) is an ionic compound arbitrarily selected from the above-mentioned non-coordinating anions and cations and combined. Among them, specific examples of the preferred ionic compound (B2) include tri (methylphenyl) carbonium tetra (pentafluorophenyl) borate, triphenylcarbonium tetra (pentafluorophenyl) borate, and N, N-dimethylanilinium tetra ( Pentafluorophenyl) borate and 1,1′-dimethylferrocenium tetra (pentafluorophenyl) borate.

Lewis Acid (B3) The Lewis acid (B3) used in the present invention can react with the transition metal compound (A) to form a cationic transition metal compound, and is not particularly limited. Number 1
And an organic boron compound having 10 to 10 hydrocarbon groups bonded thereto. The hydrogen atom of the hydrocarbon group may be substituted with a halogen atom or the like. Specific examples of the organic boron compound include trimethylboron, triphenylboron, tris (pentafluorophenyl) boron, tris (monofluorophenyl) boron, and tris (difluorophenyl) boron.

Organometallic Compound (B4) The organometallic compound (B4) used in the present invention, which is composed of a metal belonging to Groups I to III of the periodic table, is not particularly limited. Examples thereof include an organolithium compound, an organomagnesium compound, and an organoaluminum. Compounds, organoaluminum hydrides, organomagnesium halides, organoaluminum halides and the like.

Examples of the organic lithium compound include methyl lithium, butyl lithium, phenyl lithium and the like. Examples of the organomagnesium compound include dibutylmagnesium. Examples of the organoaluminum compound include trimethylaluminum, triethylaluminum, triisopropylaluminum, and triisobutylaluminum.

Examples of the organic aluminum hydride include diethyl aluminum hydride, ethyl aluminum sesquihydride and the like. Examples of the organic magnesium halide include ethyl magnesium chloride and butyl magnesium chloride.
Examples of the organoaluminum halide include dimethylaluminum chloride, diethylaluminum chloride, methylaluminum sesquichloride, ethylaluminum sesquichloride, methylaluminum dichloride, and ethylaluminum dichloride.

The amount of the cocatalyst in the polymerization catalyst used in the present invention is prepared as follows. Organoaluminum oxy compound (B1) / transition metal compound (A)
(The (B1) is calculated in terms of aluminum atom equivalent) is usually 10 to 10,000, preferably 50.
5,000, more preferably 100-3,000. The molar ratio of the ionic compound (B2) / the transition metal compound (A) is usually 0.01 to 100, preferably 0.1 to 100.
It is 10. Lewis acid (B3) / transition metal compound (A)
Is usually 0.01 to 100, preferably 0.1 to 100.
10 to 10. The molar ratio of the organometallic compound (B4) / transition metal compound (A) is usually 0.1 to 10,000, preferably 1 to 1,000.

When the amount of the cocatalyst used is small or large, the polymerization activity decreases. The respective cocatalysts can be used as a mixture. Preferred combinations of promoters include (B1) alone, (B3) alone, (B1) and (B1)
4), combinations of (B2) and (B4), and combinations of (B3) and (B4). Particularly preferred combinations of cocatalysts include (B1) alone and a combination of (B1) and (B4).

The amount of the polymerization catalyst used in the present invention is usually 0.01 to 50 mmol, preferably 0.05 to 50 mol, as the amount of the transition metal compound (A) per 1 mol of the monomer.
It is 10 mmol, more preferably 0.1 to 5 mmol. If the amount of the catalyst used is small, the polymerization activity decreases,
If the amount is large, the molecular weight of the obtained polymer decreases.

The contact aging temperature (T, ° C.) between the transition metal compound (A) and the promoter in the present invention is 0 to 50 ° C., preferably 10 to 40 ° C., and more preferably 15 to 35 ° C. If this temperature is low, the resulting polymer Mw / M
When n is large and high, the polymerization activity decreases.

The contact time (t, min) between the transition metal compound (A) and the promoter in the present invention is a time that satisfies 5 ≦ t ≦ 2000exp (−0.0921T), and 1 ≦ t ≦ 1000exp (− 0.0921T), and more preferably 2 ≦ t ≦ 500exp (−0.0921T). When the contact time is short, the Mw / Mn of the obtained polymer increases, and when the contact time is long, the polymerization activity decreases.

The transition metal compound (A) and the cocatalyst can be used in the form of either a solution or a slurry, respectively, but are preferably in the form of a solution in order to obtain a higher polymerization activity. The solvent used for preparing the solution or slurry is a hydrocarbon solvent such as butane, pentane, hexane, heptane, octane, cyclohexane, mineral oil, benzene, toluene, xylene, or chloroform, methylene chloride, dichloroethane, chlorobenzene, etc. It is a halogenated hydrocarbon solvent. These solvents may be used as a mixture of two or more kinds. Preferred solvents are aromatic hydrocarbons such as toluene and benzene.

The polymerization catalyst used in the method for producing a butadiene polymer of the present invention is used by supporting the components of the polymerization catalyst on a carrier in order to prevent contamination of the polymerization catalyst due to adhesion to the polymerization reactor. Is also good.

Examples of the carrier include carbon black, an inorganic compound, and an organic polymer compound. Examples of the inorganic compound include an inorganic oxide, an inorganic chloride, and an inorganic hydroxide, and may contain a small amount of a carbonate or a sulfate. Preferred specific examples include inorganic oxides such as silica, alumina, magnesia, titania, zirconia, and calcia, and inorganic chlorides such as magnesium chloride. These inorganic compounds have an average particle size of 5-150.
It is preferably a porous particle having a μm and a specific surface area of ² to 800 m ² / g, and is usually used as a carrier after heat treatment at 100 to 800 ° C. to remove water.

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 the side chain. These are acrylic acid, methacrylic acid,
It can be obtained by polymerizing a monomer composed of vinyl chloride, vinyl acetate, styrene, divinylbenzene or the like, or chemically modifying a polymer having an α-olefin monomer unit such as ethylene, propylene or butene. Specific examples include a carboxy-modified crosslinked styrene copolymer composed of styrene-methacrylic acid-divinylbenzene. These organic polymer compounds have an average particle diameter of 5-2.
It is preferable to use the carrier in the form of 50 μm spherical particles.

The polymerization method that can be employed in the method for producing a butadiene polymer of the present invention is not particularly limited, but includes a bulk polymerization method, a solution polymerization method and a slurry polymerization method in an inert solvent, and a gas-phase stirring tank and a gas-phase stirring tank. Gas phase polymerization using a phase fluidized bed. Among these methods,
The solution polymerization method is preferable in that the molecular weight distribution can be narrowed.
Further, both a batch polymerization method and a continuous polymerization method can be employed.

The inert solvent used in the solution polymerization method is not particularly limited, but is a hydrocarbon solvent such as butane, pentane, hexane, heptane, octane, cyclohexane, mineral oil, benzene, toluene, xylene, or chloroform, methylene. It is a halogenated hydrocarbon solvent such as chloride, dichloroethane and chlorobenzene. These solvents may be used as a mixture of two or more kinds. Preferred solvents are aromatic hydrocarbons such as toluene and benzene.

The upper limit of the polymerization temperature in the method for producing a butadiene polymer of the present invention is 0 ° C., preferably -10 ° C., more preferably -20 ° C., and the lower limit is about -100 ° C. When the polymerization temperature is high, the Mw / M
n increases. Further, a polymerization reaction at an extremely low temperature such as -100 ° C or lower is not preferable from the viewpoint of production cost.
Polymerization time is about 1 minute to 50 hours, polymerization pressure is 1 to 30k
g / cm ² .

In the method for producing a butadiene polymer of the present invention, a chain transfer agent can be added to adjust the molecular weight of the polymer. As the chain transfer agent, 1,4-
Those conventionally used in the production of cis-polybutadiene rubber can be similarly used.
-Allenes such as butadiene, cyclic dienes such as cyclooctadiene, and hydrogen.

In the method for producing a butadiene polymer of the present invention, since the polymerization reaction proceeds in a living manner, a reagent capable of reacting with a living polymer having a catalytic metal at a molecular terminal is polymerized before the termination of the polymerization reaction. It can be added to the system and reacted with the living polymer. Usually, a monofunctional reagent is called a terminal modifier, and a polyfunctional reagent is called a coupling agent. In the case of a terminal modifier, it forms a structure bonded to the end of a living polymer, and in the case of a coupling agent, a structure formed by bonding two or more living polymers. They can be used in combination.

Examples of the terminal modifier include, but are not limited to, epoxy compounds such as ethylene oxide and styrene oxide; isocyanate compounds such as phenyl isocyanate and butyl isocyanate;
4'-bis (diethylamino) benzophenone, 4,
N-substituted aminoketones such as 4'-bis (diphenylamino) benzophenone; N-substituted benzaldehydes such as 4-dimethylaminobenzaldehyde and 4-diphenylaminobenzaldehyde; N, N-diethylacetamide, N, N-dimethylaminoacetamide Carboxylic acid amides such as N-methyl-2-pyrrolidone, N
N-substituted pyrrolidones such as -phenyl-2-pyrrolidone; and the like. In the case of a terminal modifying agent, it may cause a structural change upon binding to the terminal of the living polymer and further react with another terminal of the living polymer to act as if it were a coupling agent.

The coupling agent is not particularly restricted but includes, for example, silicon halides containing at least two halogen atoms such as silicon tetrachloride, silicon tetrabromide, trichloromethylsilane, hexachlorodisilane; tetramethoxysilane; Organosilicon compounds containing two or more alkoxy groups having 1 to 8 carbon atoms, such as tetraethoxysilane, methyltrimethoxysilane, and phenyltrimethoxysilane; at least two compounds such as tin tetrachloride, tin tetrabromide, and dimethyltin dichloride And a halogenated tin compound containing a halogen atom.

When a living polymer is reacted with a terminal modifier or a coupling agent, a Mooney viscosity stabilizer is appropriately added to the obtained polymer in order to suppress a change in Mooney viscosity during storage of the polymer. It may be added in an amount. The Mooney viscosity stabilizer is not particularly limited. For example, monoamine compounds such as butylamine, hexylamine, diphenylamine, triethylamine, aniline, and benzylamine; m-phenylenediamine, N,
Polyvalent amine compounds such as N′-dimethyl-p-phenylenediamine; and the like. These compounds are 2
A mixture of more than one species may be used.

To the butadiene polymer of the present invention, an appropriate amount of an antioxidant may be added in order to prevent deterioration during removal and storage of the polymer. Antioxidants include, for example, 2,6-di-t-butyl-4-methylphenol,
Phenolic antioxidants such as 2,6-di-t-butyl-4-isobutylphenol; sulfur antioxidants such as dilaurylthiodipropionate and distearylthiodipropionate; tris (nonylphenyl) phosphite , A phosphorus-based antioxidant such as tris (2,4-di-t-butylphenyl) phosphite; phenyl-α-
Amine-based antioxidants such as naphthylamine and p-isopropoxydiphenylamine; and the like. These antioxidants may be used as a mixture of two or more.

The termination of the polymerization reaction is usually carried out at a predetermined point in time.
It is carried out by adding a polymerization terminator to the polymerization system.
Examples of the polymerization terminator include water; alcohols such as methanol, ethanol, propanol, butanol and isobutanol; inorganic acids such as hydrochloric acid; and organic acids such as citric acid, versatic acid and dodecylbenzenesulfonic acid. These polymerization terminators may be used as a mixture of two or more. The method of recovering the polymer after the termination of the polymerization reaction may be a conventional method, such as a steam stripping method or a method of precipitating the polymer in a poor solvent.

[0063]

EXAMPLES The present invention will be specifically described below with reference to examples. (Transition metal compound production example 1) (2-methoxyethyl) cyclopentadienyl trichloro
Synthesis of Rotitanium Trimethylsilylcyclopentadienyl Sodium 32
g (200 mmol) in 400 ml of tetrahydrofuran (hereinafter abbreviated as THF) solution was added to 18.9 g of chloroethyl methyl ether (2
(00 mmol) in 100 ml of THF was slowly added dropwise. After completion of the dropwise addition, the mixture was heated and refluxed overnight. Thereafter, THF was distilled off under reduced pressure, and the generated solid was separated by filtration. Then, about 33 g (85%) was obtained by vacuum distillation (80 ° C., 1 mmHg).
(2-methoxyethyl) trimethylsilylcyclopentadiene was obtained. The structure of the product was confirmed by ¹ H-NMR.

0.50 g (2.5 mmol) of (2-methoxyethyl) trimethylsilylcyclopentadiene
0 ml dry methylene chloride solution under an argon atmosphere
0.25 ml (2.2 mmol) of titanium tetrachloride at 78 ° C
Was added and stirred at room temperature for 3 hours. Then the reaction solution was
After cooling to 8 ° C., 0.43 g (yield 70%) of orange crystals precipitated were obtained. Product that is (2-methoxyethyl) cyclopentadienyl trichloro titanium ¹ H
-Confirmed by NMR.

(Transition Metal Compound Production Example 2) (2-Methoxycarbonylmethyl) cyclopentadienyl
Synthesis of rutrichlorotitanium sodium trimethylsilylcyclopentadienyl 32
g (200 mmol) in 400 ml THF solution at −78 ° C. under argon atmosphere with methyl bromoacetate 30.6.
g (200 mmol) in 100 ml THF was slowly added dropwise. After completion of the dropwise addition, stirring was further continued at -78 ° C overnight. Thereafter, THF was distilled off under reduced pressure, and the generated solid was filtered off, followed by vacuum distillation (65-66 ° C./3 mmH
g) yielded about 30 g (yield 70%) of (2-methoxycarbonylmethyl) trimethylsilylcyclopentadiene. The structure of the product was confirmed by ¹ H-NMR.

4.2 g of (2-methoxycarbonylmethyl) trimethylsilylcyclopentadiene (20 mm
3.8 g (20 mmol) of titanium tetrachloride was added to 100 ml of a dry methylene chloride solution of 1) at 0 ° C. under an argon atmosphere, followed by stirring at room temperature for 3 hours. The reaction solution was cooled to −30 ° C. to precipitate orange crystals (4.0 g, yield 70%). Product that is (2-methoxycarbonylmethyl) cyclopentadienyl-trichloro titanium ¹ H
-Confirmed by NMR.

(Transition Metal Compound Production Example 3) Trimethylsilylcyclopentadienyltrichlorotitanium
Synthesis of bis (trimethylsilyl) cyclopentadiene is described in J. Am.
C. S. It was synthesized according to the description of Dalton, 1980, p. 1156, and purified by distillation under reduced pressure. Bis (trimethylsilyl) cyclopentadiene 2.1 g (10 m
mol) in 100 ml of dry n-hexane solution at −78 ° C. under argon atmosphere at 1.1 ml of titanium tetrachloride (10 ml).
mmol) was added dropwise and stirred for 4 hours. After evaporating the solvent, 2.1 g (yield 70%) of yellow crystals were obtained by sublimation. ¹ H-NMR confirmed that the product was trimethylsilylcyclopentadienyltrichlorotitanium.

Example 1 A 300 ml pressure-resistant glass flask equipped with a stirrer was used as a polymerization vessel, and a polymerization reaction was carried out under an argon atmosphere. 86.6 g of toluene
And a toluene solution (manufactured by Tosoh Akzo Co., Ltd.) of 75.0 mmol of methylaluminoxane (in terms of an aluminum atom equivalent, and the same applies to the following) were charged and the temperature was kept at 25 ° C. Here, (2-methoxyethyl) cyclopentadienyltrichlorotitanium (hereinafter abbreviated as TiET)
After adding a 0.075 mmol toluene solution and aging at 25 ° C. for 5 minutes, it was rapidly cooled to a constant temperature of −25 ° C. A polymerization reaction was carried out by charging 7.5 g of 1,3-butadiene. Two hours, four hours, 9.5 hours, and 19.8 hours after the start of the polymerization, 10 g of the polymerization solution was collected and analyzed.

To the collected polymerization solution, a hydrochloric acid-acidic methanol solution was immediately added to stop the polymerization reaction, and the mixture was poured into a large amount of hydrochloric acid-methanol to precipitate a polymer. The operation of dissolving the polymer separated by filtration in toluene, centrifuging the solution to remove ash, and reprecipitating in acidic methanol was repeated twice. The obtained polymer was dried and weighed to determine the polymer yield.

The microstructure of the polymer was determined by NMR analysis. That is, ¹ H-NMR analysis (1,4-bond:
5.4-5.6 ppm, 1,2-bond: 5.0-5.1
ppm), the ratio of 1,4-bond to 1,2-bond in the polymer was determined, and the ratio of cis- to trans-bond was determined from ¹³ C-NMR (cis-bond: 28 ppm, trans-bond: 33 ppm). The microstructure of the coalescence was determined.

For analysis of molecular weight and molecular weight distribution, a column in which two GMHs manufactured by Tosoh Corporation were connected or a column in which G-7000 and G-5000 were connected was used, and THF was used as an eluent, and a standard was used. The number average molecular weight and molecular weight distribution were determined based on a calibration curve prepared using a polybutadiene sample (manufactured by Polymer Laboratories).
Table 1 shows catalyst preparation conditions, polymerization reaction conditions, polymerization yield, and analysis values of the polymer.

In Example 1, a high molecular weight butadiene polymer having an extremely small Mw / Mn and a high 1,4-cis bond content was obtained. Further, with the increase of the polymerization yield, Mn increased while maintaining low Mw / Mn, indicating that living polymerization was progressing.

(Comparative Example 1) 86.6 g of toluene and 15.0 mm of methylaluminoxane were placed in the same polymerization vessel as in Example 1.
ol was charged to a constant temperature of 25 ° C. Immediately after adding a 0.015 mmol toluene solution of TiET,
A polymerization reaction was carried out by charging 7.5 g of 1,3-butadiene. Four hours after the start of the polymerization, a hydrochloric acid-acidic methanol solution was added to stop the polymerization reaction. The removal and analysis of the polymer were performed in the same manner as in Example 1. Table 1 shows the results.
In Comparative Example 1, the contact time of the catalyst component was almost 0 minutes, and the polymerization temperature was high, so that the 1,4-cis bond content was slightly low and Mw / Mn was large.

Comparative Example 2 86.6 g of toluene and 15.0 mm of methylaluminoxane were placed in the same polymerization vessel as in Example 1.
ol was charged to a constant temperature of 25 ° C. To this was added a toluene solution of 0.015 mmol of TiET, and aged at 25 ° C. for 60 minutes.
5 g was charged and a polymerization reaction was carried out. Nineteen hours after the start of the polymerization, a hydrochloric acid-acidic methanol solution was added to stop the polymerization reaction. The removal and analysis of the polymer were performed in the same manner as in Example 1. Table 1 shows the results. In Comparative Example 2, since the polymerization temperature was high, the 1,4-cis bond content was slightly lower, and
Mw / Mn is large.

Comparative Example 3 86.6 g of toluene and 15.0 mm of methylaluminoxane were placed in the same polymerization vessel as in Example 1.
ol was charged to a constant temperature of -25 ° C. Here TiET
Was added to a 0.015 mmol toluene solution, and -25 was added.
After aging at 120 ° C. for 120 minutes, 7.5 g of 1,3-butadiene was charged to carry out a polymerization reaction. Two hours after the initiation of the polymerization, a methanol solution of hydrochloric acid was added to stop the polymerization reaction. Removal and analysis of the polymer was performed as described in Example 1.
The same was done. Table 1 shows the results. In Comparative Example 3, Mw / Mn was large because the contact temperature of the catalyst component was too low.

Comparative Example 4 A polymerization reaction was carried out in the same manner as in Example 1 except that the transition metal compound was changed from TiET to (2-methoxycarbonylmethyl) cyclopentadienyltrichlorotitanium (hereinafter abbreviated as TiES). Started. Three minutes after the start of the polymerization, an acidic methanol solution of hydrochloric acid was added to stop the polymerization reaction. Removal and analysis of the polymer
Performed in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 5 A polymerization reaction was started in the same manner as in Example 1 except that the transition metal compound was changed from TiET to trimethylsilylcyclopentadienyltrichlorotitanium. One hour after the start of the polymerization, an acidic methanol solution of hydrochloric acid was added to stop the polymerization reaction. The removal and analysis of the polymer were performed in the same manner as in Example 1. Table 1 shows the results. In Comparative Examples 4 and 5, Mw / Mn was small because transition metal compounds outside the scope of the present invention were used.
-Low cis bond content.

[0078]

[Table 1]

[0079]

According to the production method of the present invention, a butadiene polymer having a very narrow molecular weight distribution and a high 1,4-cis bond content can be obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Michihiko Asai 1-1 East, Tsukuba City, Ibaraki Pref. Institute of Industrial Science and Technology (72) Inventor Yasumi Suzuki 1-1 East East Tsukuba City, Ibaraki Pref. Inside the Institute of Quality Engineering (72) Inventor Satoshi Miyazawa 1-1 East Higashi Tsukuba, Ibaraki Prefectural Institute of Technology Inside the Institute of Quality Engineering (72) Inventor Kenji Tsuchihara 1-1 East Higashi Tsukuba, Ibaraki Pref. Inside the Engineering Research Institute (72) Inventor Masahide Murata 2-315-504, Suido 2-chome, Bunkyo-ku, Tokyo (72) Inventor Hiroyuki Ozaki 4-6-202 Onogawa, Tsukuba-shi, Ibaraki Prefecture (72) Inventor Masanao Kawabe 2-72-6-203 Takezono, Tsukuba-shi, Ibaraki Prefecture (72) Inventor Yoshifumi Fukui 4-63-507 Ninomiya 4-chome, Tsukuba-shi, Ibaraki Prefecture (72) Inventor Jiju 2-7-2 Kodano, Kanazawa City, Ishikawa Prefecture (72) Inventor Hideaki Hagiwara 1-1, Higashi 1-1, Tsukuba, Ibaraki Pref., National Institute of Advanced Industrial Science and Technology (72) Inventor, Toshio Kase 5-Chome, Matsushiro, Tsukuba, Ibaraki No. 2 No. 2 F term (reference) 4J028 AA01A AB01A AC01A AC10A AC28A BA00A BA01B BB00A BB01B BC01B BC05B BC06B BC12B BC13B BC15B BC16B BC17B BC19B BC25B BC27B CA03C CA27C CA28C CA29C CB09FA04 GA01 FA01 GA01 FA10

Claims (2)

[Claims] 1. A ratio (Mw / Mn) of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 1.5 or less, and Mn of 3
A butadiene polymer having a molecular weight of 0.003 to 3,000,000 and a 1,4-cis bond content of 96 mol% or more. 2. A transition metal compound belonging to Group IV of the periodic table having a cyclopentadienyl skeleton having a substituent having an ether group (A), and an organic aluminum oxy compound (B)
1) at least one cocatalyst selected from the group consisting of an ionic compound (B2), a Lewis acid (B3), and an organometallic compound (B4) comprising a metal belonging to Groups I to III of the periodic table; In the presence of a polymerization catalyst that has been previously contacted and aged under conditions satisfying the formula β,
The method for producing a butadiene polymer according to claim 1, wherein the polymerization is carried out at a temperature of not more than ℃. Formula α: 0 ≦ T ≦ 50 Formula β: 0.5 ≦ t ≦ 2000exp (−0.0921
T) Here, T is a contact temperature (° C.), and t is a contact time (minute).