WO2020116367A1

WO2020116367A1 - Polybutadiene and method for producing same

Info

Publication number: WO2020116367A1
Application number: PCT/JP2019/046938
Authority: WO
Inventors: 将山垣; 恭芳岡部; 洸神林
Original assignee: 宇部興産株式会社
Priority date: 2018-12-03
Filing date: 2019-12-02
Publication date: 2020-06-11
Also published as: TW202031695A

Abstract

The present invention provides: a polybutadiene having high linearity, and improved workability and abrasion resistance; and a method for producing same This polybutadiene can be advantageously produced by means of a polybutadiene production method in which 1,3-butadiene is polymerized in two stages. The method includes: a first polymerization step for polymerizing 1,3-butadiene using a cobalt compound (C1) and an ionic compound (D) comprising a non-coordinating anion and cation; and a second polymerization step for mixing the mixture obtained in the first polymerization step with a cobalt compound (C2) and polymerizing 1,3-butadiene.

Description

Polybutadiene and method for producing the same

The present invention relates to polybutadiene having high linearity. The present invention also relates to a method for producing highly linear polybutadiene in a high yield.

Conventionally, polybutadiene has been widely used in various fields as a thermally and mechanically excellent rubber material, but with the recent sophistication of resource and energy saving needs, polybutadiene also has durability (breaking property and resistance). Further improvement in abrasion resistance and energy loss (low loss) is required. In order to solve these problems, the development of a polymerization catalyst is the realization of a molecular design satisfying that the molecular structure of polybutadiene has a narrow molecular weight distribution, a small degree of branching of the molecular chain, and a high content of cis-1,4 bonds. Energetic research and development through

As catalysts that enable such molecular design, catalysts obtained from cobalt compounds, ionic compounds of non-coordinating anions and cations, and organoaluminum compounds are known (Patent Documents 1 to 5).

Japanese Unexamined Patent Publication No. 10-182726 JP-A-2000-17012 Japanese Patent Laid-Open No. 2000-17013 JP, 2016-148015, A JP, 2017-179117, A

By producing a polybutadiene having a small degree of branching of the molecular chain (high linearity) by using a catalyst using an ionic compound of a non-coordinating anion and a cation as described in Patent Documents 1 to 5, Although the low loss property is improved, the viscosity of the rubber composition is increased due to the structure, the processability is deteriorated, and the wear resistance is also deteriorated. Further, according to the production methods described in Patent Documents 1 to 5, polybutadiene having a small branching degree could not be produced in a high yield, and the obtained polybutadiene had a low cis content.

1. An object of the first invention is to provide a polybutadiene having high linearity and a method for producing polybutadiene having high linearity, capable of obtaining a rubber composition having improved processability and wear resistance. To do.

2. The second invention is a method for producing a polybutadiene having a high cis-1,4 bond content in a microstructure analysis (high cis) and a high linearity and a polybutadiene having a high cis and a high linearity in a high yield. The purpose is to provide.

Means for solving the problems of the first invention and the second invention relate to the following.
[1] A method for producing polybutadiene, which comprises polymerizing 1,3-butadiene in two steps,
A first polymerization step of polymerizing 1,3-butadiene using a cobalt compound (C1), a non-coordinating anion and a ionic compound (D) of a cation;
A method for producing polybutadiene, comprising a second polymerization step in which the mixture obtained in the first polymerization step and a cobalt compound (C2) are mixed to polymerize 1,3-butadiene.
[2] Production of polybutadiene of [1], further including a step of mixing 1,3-butadiene, water (A1), and an organometallic compound (B1) of an element of Groups 1, 2, and 13 of the periodic table Method.
[3] The conversion of 1,3-butadiene at the end of the first polymerization step is 20 to 50%,
The method for producing polybutadiene according to [1] or [2], wherein the final conversion rate of 1,3-butadiene at the time of completion of the second polymerization step is 75% or less.
[4] As the component (B1), a non-halogenated organometallic compound of the elements of Groups 1, 2, and 13 of the periodic table (B1a) and a halogenated organometallic compound of the elements of Groups 1, 2, and 13 of the periodic table ( B1b) and the manufacturing method of polybutadiene of [2] or [3].
[5] (B1a) the amount of components and b1 _a molar, when the b1 _b molar usage (B1b) component,
0.10≦b1 _b /(b1 _a +b1 _b )≦0.60
[4] The method for producing polybutadiene according to [4].
[6] The Mooney viscosity (ML _{1+4,100° C.} ) is 43 to 80,
The ratio (Tcp/ML _{1+4,100° C.} ) of the 5 wt% toluene solution viscosity (Tcp) and the Mooney viscosity (ML _1+4,100° _C. ) is 2.2 to 4.0,
ML _{1+4,100° C.} When the torque at the end of measurement is set to 100%, the stress relaxation time (T80) until the value decreases by 80% is 2.0 to 7.0 seconds,
The ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) is 2.40 to 4.00,
A polybutadiene having a ratio (Mz/Mw) of z-average molecular weight (Mz) to number-average molecular weight (Mw) of 1.80 to 3.00.
[7] The polybutadiene according to [6], which has a 5 wt% toluene solution viscosity (Tcp) of 100 to 300.
[8] The polybutadiene according to [6] or [7], which has a weight average molecular weight (Mw) of 40.0×10 ⁴ to 75.0×10 ⁴ .
[9] The polybutadiene rubber according to [6] to [8], which has a number average molecular weight (Mn) of 15.0×10 ⁴ to 30.0×10 ⁴ .
[10] A non-halogenated organometallic compound (B1) of elements of Groups 1, 2, and 13 of the periodic table and a halogenated organometallic compound (B2) of elements of Groups 1, 2, and 13 of the periodic table are used in combination. The step of polymerizing 1,3-polybutadiene,
When the amount of the component (B1) used is b1 mol and the amount of the component (B2) used is b2 mol,
0.10≦b2/(b1+b2)≦0.60
A method for producing polybutadiene that satisfies the above conditions.
[11] The step of polymerizing the 1,3-polybutadiene is
1,3-Butadiene, water (A), non-halogenated organometallic compound (B1) of elements of Groups 1, 2, and 13 of the periodic table, and halogenation of elements of Groups 1, 2, and 13 of the periodic table A step of mixing with the organometallic compound (B2),
Of the polybutadiene of [10], which comprises a step of mixing the obtained mixture, a cobalt compound (C), an ionic compound (D) of a non-coordinating anion and a cation, and polymerizing 1,3-butadiene. Production method.
[12] The non-halogenated organometallic compound (B1) is a non-halogenated organoaluminum compound, and the halogenated organometallic compound (B2) is a halogenated organoaluminum compound [4], [5]. The method for producing polybutadiene according to [10] or [11].
[13] The ionic compound (D) of a nonionic anion and a cation is triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate and 1,1′- The method for producing polybutadiene according to [1] to [5] or [10] to [12], containing at least one member selected from the group consisting of dimethylferrocenium tetrakis(pentafluorophenyl)borate.
[14] Polybutadiene obtained by the method for producing polybutadiene according to [1] to [5] or [10] to [13].
[15] The ratio of the weight average molecular weight to the number average molecular weight (Mw/Mn) in terms of polystyrene by GPC is 2.0 to 2.5,
The ratio (Tcp/ML) of the 5 wt% toluene solution viscosity (Tcp) and the Mooney viscosity (ML _{1+4,100° C.} ) is 2.5 to 6.0,
The cis-1,4 bond content in the microstructure analysis is 98.5 mol% or more,
Polybutadiene having a halogen content of 1 to 60 μg/g.
[16] The polybutadiene according to [15], which has a Mooney viscosity (ML _{1+4,100° C.} ) of 30 to 100.
[17] The polybutadiene according to [15] or [16], which has a ratio (Mz/Mw) of z average molecular weight (Mz) to number average molecular weight (Mw) of 1.60 or more and less than 2.00.
[18] A rubber composition containing the polybutadiene of [6] to [9] or [14] to [17].
[19] A tire using the rubber composition according to [18].

1. Effect of the First Invention According to the first invention, it is possible to provide a polybutadiene having a high linearity and a method for producing a polybutadiene having a high linearity, which makes it possible to obtain a rubber composition having improved processability and abrasion resistance.
2. Effect of the Second Invention According to the second invention, a method for producing a polybutadiene having a high cis-1,4 bond content in a microstructure analysis (high cis) and a high linearity and a polybutadiene having a high cis and a high linearity in a high yield is provided. Can be provided.

3 is a graph showing the relationship between the Mooney viscosity (Polymer ML) of polybutadiene and the INDEX value of the Mooney viscosity (Compound ML) of a rubber composition in the results of Examples and Comparative Examples. 7 is a graph showing the relationship between the Mooney viscosity (Polymer ML) of polybutadiene and the INDEX value of tan δ of the rubber composition in the results of Examples and Comparative Examples. 3 is a graph showing the relationship between the Mooney viscosity (Polymer ML) of polybutadiene and the INDEX value of the Lambourn abrasion coefficient of the rubber composition in the results of Examples and Comparative Examples. It is a graph which shows the relationship of b2/(b1+b2) and the yield based on the result of an Example and a comparative example. It is a graph which shows the relationship of b2/(b1+b2) and Tcp/ML based on the result of an Example and a comparative example.

1. First invention <<Polybutadiene (1)>>
The first invention relates to the following.
[1] A method for producing polybutadiene, which comprises polymerizing 1,3-butadiene in two steps,
A first polymerization step of polymerizing 1,3-butadiene using a cobalt compound (C1), a non-coordinating anion and a ionic compound (D) of a cation;
A method for producing polybutadiene, comprising a second polymerization step in which the mixture obtained in the first polymerization step and a cobalt compound (C2) are mixed to polymerize 1,3-butadiene.
[2] Production of polybutadiene of [1], further including a step of mixing 1,3-butadiene, water (A1), and an organometallic compound (B1) of an element of Groups 1, 2, and 13 of the periodic table Method.
[3] The conversion of 1,3-butadiene at the end of the first polymerization step is 20 to 50%,
The method for producing polybutadiene according to [1] or [2], wherein the final conversion rate of 1,3-butadiene at the time of completion of the second polymerization step is 75% or less.
[4] As the component (B1), a non-halogenated organometallic compound of the elements of Groups 1, 2, and 13 of the periodic table (B1a) and a halogenated organometallic compound of the elements of Groups 1, 2, and 13 of the periodic table ( B1b) and the manufacturing method of polybutadiene of [2] or [3].
[5] (B1a) the amount of components and b1 _a molar, when the b1 _b molar usage (B1b) component,
0.10≦b1 _b /(b1 _a +b1 _b )≦0.60
[4] The method for producing polybutadiene according to [4].
[6] The ionic compound (D) of a nonionic anion and a cation is triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate and 1,1′- The method for producing polybutadiene according to [1] to [5], which comprises at least one member selected from the group consisting of dimethylferrocenium tetrakis(pentafluorophenyl)borate.
[7] Polybutadiene obtained by the method for producing polybutadiene according to [1] to [6].
[8] Mooney viscosity (ML _{1+4,100° C.} ) is 43 to 80,
The ratio (Tcp/ML _{1+4,100° C.} ) of the 5 wt% toluene solution viscosity (Tcp) and the Mooney viscosity (ML _1+4,100° _C. ) is 2.2 to 4.0,
ML _{1+4,100° C.} When the torque at the end of measurement is set to 100%, the stress relaxation time (T80) until the value decreases by 80% is 2.0 to 7.0 seconds,
The ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) is 2.40 to 4.00,
A polybutadiene having a ratio (Mz/Mw) of z-average molecular weight (Mz) to number-average molecular weight (Mw) of 1.80 to 3.00.
[9] The polybutadiene according to [8], which has a 5 wt% toluene solution viscosity (Tcp) of 100 to 300.
[10] The polybutadiene according to [8] or [9], which has a weight average molecular weight (Mw) of 40.0×10 ⁴ to 75.0×10 ⁴ .
[11] The polybutadiene rubber according to [8] to [10], which has a number average molecular weight (Mn) of 15.0×10 ⁴ to 30.0×10 ⁴ .
[12] A rubber composition containing the polybutadiene of [7] to [11].
[13] A tire using the rubber composition according to [12].

<Method for producing polybutadiene>
In the present invention, 1,3-butadiene is polymerized in two stages. More specifically, polybutadiene having high linearity is produced by the first-stage polymerization (first polymerization step), and the polybutadiene obtained in the first-polymerization step by the second-stage polymerization (second polymerization step). While maintaining the linearity of, it is branched into a comb shape. By doing so, it is possible to obtain a polybutadiene having a high linearity, which is capable of obtaining a rubber composition having improved processability and abrasion resistance.
The method for producing polybutadiene of the present invention comprises a first polymerization step of polymerizing 1,3-butadiene using a cobalt compound (C1), an ionic compound (D) of a non-coordinating anion and a cation,
The method has a second polymerization step of mixing the mixture obtained in the first polymerization step and a cobalt compound (C2) to polymerize 1,3-butadiene.
The method for producing polybutadiene of the present invention further comprises a step of mixing 1,3-butadiene, water (A1), and an organometallic compound (B1) of an element of Groups 1, 2, and 13 of the periodic table. Is preferred, and a step of mixing (I) 1,3-butadiene and an organometallic compound (B1) of an element of Groups 1, 2, and 13 of the periodic table,
(II) First polymerization in which the mixture obtained in step (I), the cobalt compound (C1), and the ionic compound (D) of a non-coordinating anion and a cation are mixed to polymerize 1,3-butadiene Process,
(III) It is preferable to have a second polymerization step in which the mixture obtained in step (II) (first polymerization step) and the cobalt compound (C2) are mixed to polymerize 1,3-butadiene.
In particular, the method for producing polybutadiene of the present invention comprises: (I) 1,3-butadiene in the presence of water (A1) and an organometallic compound (B1) of Group 1, 2, or 13 of the periodic table. A step of mixing,
(II) By adding the cobalt compound (C1) and the ionic compound (D) of the non-coordinating anion and the cation to the mixture obtained in the step (I) at the same time or at intervals of less than 3 minutes. Polymerizing 1,3-butadiene,
(III) To the mixture obtained in the step (II), water (A2), an organometallic compound (B2) of Group 1, 2, and 13 elements of the periodic table, and a cobalt compound (C2) are added. Therefore, it is preferable to have a step of polymerizing 1,3-butadiene.
The elements of Groups 1, 2, and 13 of the Periodic Table are elements of Groups I to III of the Periodic Table in the old IUPAC.

[First polymerization step]
In the present invention, first, water (A1), an organometallic compound (B1) of an element of Groups 1, 2, and 13 of the periodic table, a cobalt compound (C1), and an ionic compound (D) of a non-coordinating anion and a cation. Polybutadiene having high linearity can be produced by polymerizing 1,3-butadiene with a catalyst containing

((A1) component: water)
As the water as the component (A1), ion-exchanged water or pure water can be used.

(Component (B1): Organometallic compound of Group 1, 2 and 13 elements of the periodic table)
In the present invention, the non-halogenated organometallic compound (B1a) of the elements of Groups 1, 2, and 13 of the Periodic Table as the organometallic compound of the elements of Groups 1, 2, and 13 of the Periodic Table of the component (B1) The halogenated organometallic compound (B1b) of Group 1, 2, and 13 elements of the table can be used, but it is preferable to use the component (B1a) and the component (B1b) together. By doing so, the yield of polybutadiene can be significantly improved, and the linearity of the polybutadiene obtained can be increased.

(Component (B1a): Nonhalogenated Organometallic Compound of Group 1, 2 and 13 Elements of the Periodic Table)
As the non-halogenated organometallic compound of Group 1, 2 and 13 elements of the periodic table of the component (B1a), non-halogenated organolithium compounds, non-halogenated organomagnesium compounds, non-halogenated organoaluminum compounds and the like are used. .. Of these, non-halogenated organoaluminum compounds are preferable. As the non-halogenated organoaluminum compound, trialkylaluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum; diethylaluminum hydride, diisobutylaluminum hydride, sesquiethylaluminum hydride, etc. Alkyl aluminum hydride is mentioned. The non-halogenated organometallic compounds of the elements of Groups 1, 2, and 13 of the Periodic Table may be used alone or in combination of two or more.

(Component (B1b): Halogenated Organometallic Compound of Group 1, 2 and 13 Elements of the Periodic Table)
As the halogenated organometallic compound of the elements of Groups 1, 2, and 13 of the periodic table of the component (B1b), a halogenated organolithium compound, a halogenated organomagnesium compound, a halogenated organoaluminum compound, or the like is used. Of these, halogenated organoaluminum compounds are preferable. Examples of the halogenated organoaluminum compound include dialkyl aluminum chlorides such as dimethyl aluminum chloride and diethyl aluminum chloride; dialkyl aluminum bromides such as dimethyl aluminum bromide and diethyl aluminum bromide; alkyl aluminum sesquichlorides such as methyl aluminum sesquichloride and ethyl aluminum sesquichloride; Examples thereof include alkylaluminum sesquibromide and methylaluminum sesquibromide. The halogenated organometallic compounds of Group 1, 2, and 13 elements of the periodic table may be used alone or in combination of two or more.

(Molar ratio of component (B1a) and component (B1b))
Proportion of Using and (B1a) component and (B1b) component, the amount of (B1a) component and b1 _a molar, when the b1 _b molar usage (B1b) component, 0.10 It is preferable to satisfy ≦b1 _b /(b1 _a +b1 _b )≦0.60. If the blending ratio of the component (B1a) is too small, the yield of polybutadiene will be low, and if the blending ratio of the component (B1a) is too large, the linearity of the polybutadiene obtained will be low. The yield of polybutadiene can be significantly improved, and the linearity of the polybutadiene obtained can be increased. b1 _b /(b1 _a +b1 _b ) is preferably 0.14 or more, more preferably 0.17 or more, still more preferably 0.20 or more. b1 _b /(b1 _a +b1 _b ) is preferably 0.50 or less, more preferably 0.40 or less, and further preferably 0.30 or more.

((C1) component: cobalt compound)
As the cobalt compound as the component (C1), a salt or complex of cobalt is preferably used. Particularly preferred are cobalt chloride, cobalt bromide, cobalt nitrate, cobalt octylate, cobalt naphthenate, cobalt acetate, cobalt malonate and other cobalt salts, cobalt bisacetylacetonate and trisacetylacetonate, ethyl acetoacetate. Examples thereof include ester cobalt, organic base complexes such as cobalt pyridine complex and picoline complex, and cobalt ethyl alcohol complex. The cobalt compounds may be used alone or in combination of two or more.

(Component (D): ionic compound of non-coordinating anion and cation)
Examples of the non-coordinating anion constituting the ionic compound of the non-coordinating anion and the cation of the component (D) include tetra(phenyl)borate, tetra(fluorophenyl)borate, tetrakis(difluorophenyl)borate, Tetrakis(trifluorophenyl)borate, Tetrakis(tetrafluorophenyl)borate, Tetrakis(pentafluorophenyl)borate, Tetrakis(tetrafluoromethylphenyl)borate, Tetrakis(3,5-bistrifluoromethylphenyl)borate, Tetra(toluyl) Examples thereof include borate, tetra(xylyl)borate, (triphenyl, pentafluorophenyl)borate, [tris(pentafluorophenyl),phenyl]borate, and tridecahydride-7,8-dicarbaundecaborate.

On the other hand, the cation constituting the ionic compound of the non-coordinating anion and the cation of the component (D) has a carbenium cation, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptatrienyl cation, and a transition metal. Examples thereof include ferrocenium cation.

Specific examples of the carbenium cation include trisubstituted carbenium cations such as triphenyl carbenium cation and tri-substituted phenyl carbenium cation. Specific examples of the tri-substituted phenylcarbenium cation include a tri(methylphenyl)carbenium cation and a tri(dimethylphenyl)carbenium cation.

Specific examples of the ammonium cation include trimethylammonium cation, triethylammonium cation, tripropylammonium cation, tributylammonium cation, tri(n-butyl)ammonium cation and other trialkylammonium cations, N,N-dimethylanilinium cations, N ,N-diethylanilinium cation, N,N-dialkylanilinium cation such as N,N-2,4,6-pentamethylanilinium cation, di(i-propyl)ammonium cation, dialkylammonium such as dicyclohexylammonium cation Examples include cations.

Specific examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tri(methylphenyl)phosphonium cation, and tri(dimethylphenyl)phosphonium cation.

The ionic compound can be preferably used by arbitrarily selecting and combining from the non-coordinating anions and cations exemplified above. Among them, as the ionic compound, triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, 1,1′-dimethylferrocenium tetrakis(pentafluorophenyl) Borate and the like are preferable, and consist of triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate and 1,1′-dimethylferrocenium tetrakis(pentafluorophenyl)borate. It is more preferable to include at least one selected from the group. The ionic compounds may be used alone or in combination of two or more.

(Molar ratio of component (A1) to component (D))
The blending ratio of the components (A1) to (D) may be appropriately set according to various conditions. The molar ratio of the component (C1) to the component (D) is preferably 1:0.1 to 10, more preferably 1:0.2 to 5. The molar ratio of the component (C1) to the component (B1) is preferably 1:0.5 to 5000, more preferably 1:5 to 2500. The molar ratio of the component (B1) to the component (A1) is preferably 1:0.01 to 2, more preferably 1:0.01 to 1.5, and further preferably 1:0.1 to 1.5. ..

(Mixing or adding order of each component)
Regarding the order of mixing or adding each component, first, 1,3-butadiene is mixed with the organometallic compound (B1) of the elements of Groups 1, 2, and 13 of the periodic table (first mixing step). In the first mixing step, it is preferable to mix water (A1) and the organometallic compound (B1) of the elements of Groups 1, 2, and 13 of the periodic table in the presence of 1,3-butadiene. Then, the obtained mixture, the cobalt compound (C1), and the ionic compound (D) of a non-coordinating anion and a cation are mixed (second mixing step). In the second mixing step, it is preferable to add the cobalt compound (C1) and the ionic compound (D) of a non-coordinating anion and a cation to the obtained mixture. By producing polybutadiene by such a process, the linearity of the obtained polybutadiene becomes high.

In the first mixing step, the co-catalyst for polymerizing 1,3-butadiene is formed by adding the (A1) component and the (B1) component in the presence of 1,3-butadiene. The component (A1) and the component (B1) may be added simultaneously or may be added at intervals, but it is more preferable to add the component (B1) after adding the component (A1). When the component (B1a) and the component (B1b) are used in combination, the addition order of the component (B1a) and the component (B1b) is arbitrary.

In the first mixing step, it is preferable to add the (A1) component and the (B1) component in the presence of 1,3-butadiene and then to age. The aging temperature is preferably −50 to 80° C., more preferably −10 to 50° C. The aging time is preferably 0.01 to 24 hours, more preferably 0.05 to 5 hours, and even more preferably 0.1 to 3 hours.

In the first polymerization step, 1,3-butadiene is polymerized by adding the component (C1) and the component (D) to the mixture obtained in the first mixing step. The component (C1) and the component (D) may be added at the same time. You may add at intervals. By adding the component (A1) and the component (B1) in the presence of 1,3-butadiene in the first mixing step, a cocatalyst for polymerizing 1,3-butadiene is formed. This is because when the C1) component comes into contact, an effective and homogeneous active species is first formed.

However, when the component (C1) is added prior to the component (D), it is preferable to add the component (C1) and the component (D) at the same time or at intervals of less than 3 minutes, and preferably 2 minutes or less. It is more preferable to add them at intervals, and it is more preferable to add them at intervals of 1 minute or less. If an interval of 3 minutes or more is provided, an inhomogeneous active species is formed and an ultrahigh molecular weight component is produced, and it becomes difficult to obtain a polybutadiene having a desired Mw/Mn. On the contrary, by adding the component (C1) and the component (D) at the same time or at intervals of less than 3 minutes, polybutadiene having a desired Mw/Mn can be obtained, and the fracture strength, abrasion resistance and low loss property can be obtained. It becomes easier to obtain polybutadiene that can improve the balance of

Each component can be used while being supported by an inorganic compound or an organic polymer compound.

(solvent)
A solvent can be used during the polymerization of 1,3-butadiene. Examples of the solvent include aromatic hydrocarbon solvents such as toluene, benzene and xylene, saturated aliphatic hydrocarbon solvents such as n-hexane, butane, heptane and pentane, alicyclic hydrocarbon solvents such as cyclopentane and cyclohexane, 1- Olefinic hydrocarbon solvents such as C4 fractions such as butene, cis-2-butene, trans-2-butene, petroleum hydrocarbon solvents such as mineral spirits, solvent naphtha and kerosene, halogenated hydrocarbons such as methylene chloride A solvent etc. are mentioned. Further, 1,3-butadiene itself may be used as the polymerization solvent. Among them, benzene, cyclohexane, a mixture of cis-2-butene and trans-2-butene, etc. are preferably used.

(Molecular weight regulator)
A molecular weight modifier can be used during the polymerization of 1,3-butadiene. As the molecular weight modifier, non-conjugated dienes such as cyclooctadiene and allene, and α-olefins such as ethylene, propylene and butene-1 can be used. Cyclooctadiene is particularly preferable, and the amount thereof used is preferably 30 mmol or less, and more preferably 5 mmol or less per mol of 1,3-butadiene. If the amount of the molecular weight regulator exceeds this range, the problem of ML viscosity shift may occur.

(Polymerization temperature and polymerization time)
The polymerization temperature is preferably in the range of -30 to 100°C, particularly preferably in the range of 30 to 80°C. The polymerization time is preferably in the range of 10 minutes to 12 hours. The polymerization pressure is normal pressure or pressure up to about 10 atm (gauge pressure).

(Conversion rate)
The conversion rate of 1,3-butadiene at the end of the first polymerization step is preferably 20 to 50%. If the conversion rate is too low, the abrasion resistance of the rubber composition using the obtained polybutadiene tends to decrease, and if the conversion rate is too high, the processability of the rubber composition using the obtained polybutadiene decreases. There is a tendency. The conversion rate of 1,3-butadiene at the time of completion of the first polymerization step is more preferably 25 to 48%, further preferably 30 to 41%.

[Second polymerization step]
In the present invention, after performing the first polymerization step, the mixture obtained in the first polymerization step is mixed with the cobalt compound (C2) to polymerize 1,3-polybutadiene. In the second polymerization step, the mixture obtained in the first polymerization step, the cobalt catalyst (C2), water (A2), and the organometallic compound (B2) of the elements of Groups 1, 2, and 13 of the periodic table are mixed. Alternatively, 1,3-polybutadiene may be polymerized.
In the second polymerization step, a cobalt compound (C2) is added to the mixture obtained in the first polymerization step, or water (A2) and an organometallic compound of an element of Groups 1, 2 and 13 of the periodic table are added. It is preferable to add (B2) and polymerize 1,3-butadiene. By doing so, it is possible to branch in a comb shape while maintaining the linearity of the polybutadiene obtained in the first polymerization step.

As the water (A2), the same water as the water (A1) used in the first polymerization step can be used. As the organometallic compound (B2) of the elements 1, 2 and 13 of the periodic table, the same as the organometallic compound (B1) of the elements 1, 2 and 13 of the periodic table used in the first polymerization step. Can be used. More specifically, the non-halogenated organometallic compound (B1a) of the elements of Groups 1, 2, and 13 of the Periodic Table is used as the organometallic compound of the elements of Groups 1, 2, and 13 of the Periodic Table (B2). Alternatively, a halogenated organometallic compound (B1b) of Group 1, 2, or 13 elements of the periodic table can be used. Only the component (B1a) may be used, only the component (B1b) may be used, or the component (B1a) and the component (B1b) may be used in combination. As the cobalt compound (C2), the same one as the cobalt compound (C1) used in the first polymerization step can be used. However, in the second polymerization step, it is preferable not to use the non-coordinating anion and cation ionic compound (D) used in the first polymerization step.

(Molar ratio of component (A2) to component (C2))
The blending ratio of the components (A2) to (C2) may be appropriately set according to various conditions. The molar ratio of the component (C2) to the component (B2) is preferably 1:0.5 to 5000, more preferably 1:5 to 2500. The molar ratio of the component (B2) and the component (A2) is preferably 1:0.01 to 2, more preferably 1:0.01 to 1.5, and further preferably 1:0.1 to 1.5. ..

(Mixing or adding order of each component)
Regarding the order of mixing or adding each component, for example, the reaction mixture obtained in the first polymerization step may be mixed with the cobalt compound (C2), and further, water (A2) and the periodic table first You may mix with the organometallic compound (B2) of a 2nd, 13th group element. By adding the component (A2) and the component (B2), a new co-catalyst for polymerizing 1,3-butadiene is formed, and the co-catalyst is effective and homogeneous because the (C2) component is in contact with the co-catalyst. This is because active species are formed. When only the cobalt compound (C2) is mixed in the reaction mixture obtained in the first polymerization step, the components (A1) and (B1) mixed in the first polymerization step are (A2) component and (B2) component. Function as.

Each component can be used while being supported by an inorganic compound or an organic polymer compound. During the polymerization of 1,3-butadiene, the same solvent as in the first polymerization step can be used, and the same molecular weight modifier as in the first polymerization step can be used. The polymerization temperature, the polymerization time, and the polymerization pressure can be the same as in the first polymerization step.

(Conversion rate)
The final conversion rate of 1,3-butadiene at the time of completion of the second polymerization step is preferably 75% or less, and more preferably less than 75%. If the final conversion rate is too high, the abrasion resistance of the obtained polybutadiene tends to decrease, and if the final conversion rate is too low, the processability of the obtained polybutadiene tends to decrease. The final conversion rate of 1,3-butadiene at the time of completion of the second polymerization step is more preferably 50 to 73%, particularly preferably 53 to 70%.

<Polybutadiene>
The polybutadiene according to the present invention, which is preferably obtained by the above production method, satisfies the following conditions.

In the polybutadiene according to the present invention, the Mooney viscosity (ML _{1+4,100° C.} ) is _43-80 . When the Mooney viscosity (ML _{1+4,100° C.} ) is 43 or more, abrasion resistance is further improved. On the other hand, when the Mooney viscosity (ML _{1+4,100° C.} ) is 80 or less, the workability is further improved. The Mooney viscosity (ML _{1+4,100° C.} ) is more preferably 45 to 75, further preferably 48 to 73, and particularly preferably 50 to 70. The Mooney viscosity (ML _{1+4,100° C.} ) can be measured by the method described in Examples below.

The polybutadiene according to the present invention preferably has a 5 wt% toluene solution viscosity (Tcp) of 100 to 300. If the 5 wt% toluene solution viscosity (Tcp) is 100 or more, the abrasion resistance is further improved. On the other hand, if the 5 wt% toluene solution viscosity (Tcp) is 300 or less, the workability is further improved. The 5 wt% toluene solution viscosity (Tcp) is more preferably 120 to 270, further preferably 130 to 210. The 5 wt% toluene solution viscosity (Tcp) can be measured by the method described in Examples below.

In the polybutadiene according to the present invention, the ratio (Tcp/ML) of the 5 wt% toluene solution viscosity (Tcp) and the Mooney viscosity (ML _{1+4,100° C.} ) is 2.2 to 4.0. It should be noted that Tcp/ML is an index of the degree of branching (linearity). When Tcp/ML is 2.2 or more, the degree of branching is low (high linearity), and the low loss property and the wear resistance are further improved. On the other hand, when Tcp/ML is 4.0 or less, cold flow caused by a high degree of branching (low linearity) can be suppressed, and the storage stability of the product is further improved. The Tcp/ML is more preferably 2.4 to 3.7, further preferably 2.6 to 3.1.

In the polybutadiene according to the present invention, when the torque at the end of measurement of ML _{1+4,100° C.} is 100%, the stress relaxation time (T80) until the value is attenuated by 80% is 2.0 to 7.0 seconds. is there. When T80 is 2.0 seconds or more, the retention of the shear stress due to the entanglement of rubber molecules becomes sufficient, and a good filler dispersion state is easily obtained. On the other hand, when T80 is 7.0 seconds or less, the residual stress at the time of molding is reduced, so that the dimensional stability is excellent and the workability is further improved. The stress relaxation time (T80) is more preferably 2.3 to 6.0 seconds, further preferably 2.5 to 5.3 seconds. The stress relaxation time (T80) can be measured by the method described in Examples below. The transition of the stress relaxation of rubber is determined by the combination of the elastic component and the viscous component. Slow stress relaxation indicates that there are many elastic components, and fast stress relaxation indicates that there are many viscous components.

In the polybutadiene of the present invention, the number average molecular weight (Mn) is preferably 15.0×10 ⁴ to 30.0×10 ⁴ . When the number average molecular weight (Mn) is 15.0×10 ⁴ or more, abrasion resistance is further improved. On the other hand, when the number average molecular weight (Mn) is 30.0×10 ⁴ or less, workability is further improved. The number average molecular weight (Mn) is more preferably 16.0×10 ⁴ to 27.0×10 ⁴ , and further preferably 17.0×10 ⁴ to 25.0×10 ⁴ . The number average molecular weight (Mn) can be measured by the method described in Examples below.

In the polybutadiene of the present invention, the weight average molecular weight (Mw) is preferably 40.0×10 ⁴ to 75.0×10 ⁴ . When the weight average molecular weight (Mw) is 40.0×10 ⁴ or more, abrasion resistance is further improved. On the other hand, when the weight average molecular weight (Mw) is 75.0×10 ⁴ or less, workability is further improved. The weight average molecular weight (Mw) is more preferably 45.0×10 ⁴ to 70.0×10 ⁴ , and further preferably 50.0×10 ⁴ to 65.0×10 ⁴ . The weight average molecular weight (Mw) can be measured by the method described in Examples below.

In the polybutadiene of the present invention, the ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) is 2.40 to 4.00. If Mw/Mn is 2.40 or more, workability is further improved. On the other hand, when Mw/Mn is 4.00 or less, wear resistance is further improved. The molecular weight distribution (Mw/Mn) is more preferably 2.40 to 3.50, further preferably 2.50 to 3.20.

In the polybutadiene of the present invention, the z-average molecular weight (Mz) is preferably 100.0×10 ⁴ to 180.0×10 ⁴ . When the z-average molecular weight (Mz) is 100.0×10 ⁴ or more, abrasion resistance is further improved. On the other hand, if the z-average molecular weight (Mz) is 180.0×10 ⁴ or less, the workability is further improved. The z-average molecular weight (Mz) is more preferably 110.0×10 ⁴ to 170.0×10 ⁴ , and further preferably 114.0×10 ⁴ to 160.0×10 ⁴ . The z-average molecular weight (Mz) can be measured by the method described in Examples below.

In the polybutadiene of the present invention, the ratio (Mz/Mw) of the z average molecular weight (Mz) and the weight average molecular weight (Mw) is 1.80 to 3.00. If Mz/Mw is 1.80 or more, workability is further improved. On the other hand, when Mz/Mw is 3.00 or less, wear resistance is further improved. The Mz/Mw is more preferably 1.90 to 2.70, further preferably 2.00 to 2.60.

In the polybutadiene according to the present invention, the proportion of 1,4-cis structure in microstructure analysis is preferably 95.0% or more. When the ratio of the 1,4-cis structure is 95.0% or more, the wear resistance is further improved. The ratio of the 1,4-cis structure is preferably 97.0% or more, more preferably 98.0% or more. The ratio of 1,4-cis structure is usually 99.0% or less. The proportion of the 1,4-trans structure in the microstructure analysis is preferably 1.5% or less, more preferably 1.0% or less. The ratio of 1,4-trans structure is usually 0.5% or more. The ratio of the 1,2-vinyl structure in the microstructure analysis is preferably 1.5% or less, more preferably 1.2% or less. The proportion of 1,2-vinyl structure is usually 0.5% or more. The proportions of the 1,4-cis structure, the 1,4-trans structure and the 1,2-vinyl structure in the microstructure analysis can be measured by the method described in Examples below.

In particular, the polybutadiene according to the present invention has a ratio (Tcp/ML _{1+4,100° C.} ) of 5 wt% toluene solution viscosity (Tcp) to Mooney viscosity (ML _1+4,100° _C. ) and a stress relaxation time (T80). , The ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw/Mn), and the ratio of the z average molecular weight (Mz) to the number average molecular weight (Mw) (Mz/Mw) are satisfied in combination. 5% by weight toluene solution viscosity (Tcp) to Mooney viscosity (ML _{1+4,100° C.} ) (Tcp/ML _{1+4,100° C.} ), stress relaxation time (T80), weight average molecular weight (Mw) and number average The conditions of the ratio of molecular weight (Mn) (Mw/Mn), the ratio of z-average molecular weight (Mz) to the number-average molecular weight (Mw) (Mz/Mw), and the Mooney viscosity (ML _{1+4, 100° C.} ) are satisfied in combination. Is more preferable.

In the polybutadiene of the present invention, the polybutadiene may or may not be modified with disulfur dichloride, monosulfur monochloride, other sulfur compounds, organic peroxides, t-butyl chloride, or the like.

<Rubber composition>
The rubber composition contains the polybutadiene obtained by the production method or the polybutadiene.
A rubber composition can be obtained by mixing the polybutadiene according to the present invention with other components. The rubber composition contains the polybutadiene according to the present invention. The polybutadiene according to the present invention, alone or blended with another synthetic rubber or natural rubber, is oil-extended with a process oil if necessary, and then a reinforcing agent such as carbon black or silica, a process oil, an antioxidant, It is vulcanized by adding vulcanizing agents, vulcanization aids, and other compounding agents, such as industrial products such as tires, anti-vibration rubbers, belts, hoses, and seismic isolation rubbers, and footwear such as men's shoes, women's shoes and sports shoes Used for various rubber applications. In that case, it is preferable that the rubber component contains at least 10% by weight of the polybutadiene according to the present invention.

As the other synthetic rubber contained in the rubber composition, a vulcanizable rubber is preferable, and specifically, ethylene propylene diene rubber (EPDM), nitrile rubber (NBR), butyl rubber (IIR), chloroprene rubber (CR), Examples thereof include polyisoprene, high cis polybutadiene rubber, low cis polybutadiene rubber (BR), styrene-butadiene rubber (SBR), butyl rubber, chlorinated butyl rubber, brominated butyl rubber and acrylonitrile-butadiene rubber. Derivatives of these rubbers, for example, polybutadiene modified with a tin compound, rubber modified with epoxy, silane, or maleic acid can also be used. Other synthetic rubbers may be used alone or in combination of two or more.

As the reinforcing agent, carbon black, silica, activated calcium carbonate, inorganic reinforcing agents such as ultrafine magnesium silicate, syndiotactic 1.2 polybutadiene resin, polyethylene resin, polypropylene resin, high styrene resin, phenol resin, lignin, modified Organic reinforcing agents such as melamine resin, coumarone indene resin, petroleum resin and the like can be mentioned. Of these, carbon black is preferable. As the carbon black, carbon black having a particle size of 90 nm or less and a dibutyl phthalate (DBP) oil absorption of 70 ml/100 g or more is preferable. As the type of carbon black, for example, FEF, FF, GPF, SAF, ISAF, SRF, HAF and the like are preferably used.

The process oil may be any of aromatic, naphthenic and paraffinic.

Aging examples include amine/ketone-based, imidazole-based, amine-based, phenol-based, sulfur-based and phosphorus-based antioxidants.

As the vulcanizing agent, known vulcanizing agents such as sulfur, organic peroxides, resin vulcanizing agents, and metal oxides such as magnesium oxide are used.

As the vulcanization aid, known vulcanization aids such as aldehydes, ammonias, amines, guanidines, thioureas, thiazoles, thiurams, dithiocarbamates and xanthates can be used.

As one of the other compounding agents, fillers include inorganic fillers such as calcium carbonate, basic magnesium carbonate, clay, Lissajous and diatomaceous earth, and organic fillers such as recycled rubber and powdered rubber.

The silane coupling agent, which is also one of the other compounding agents, includes an organosilicon compound represented by the general formula R7 _n SiX _4-n , and R7 is a vinyl group, an acyl group, an allyl group, an allyloxy group. An organic group having 1 to 20 carbon atoms having a reactive group selected from a group, an amino group, an epoxy group, a mercapto group, a chloro group, an alkyl group, a phenyl group, hydrogen, a styryl group, a methacrylic group, an acryl group and a ureido group. X is a hydrolyzable group selected from a chloro group, an alkoxy group, an acetoxy group, an isopropenoxy group, an amino group, and the like, and n represents an integer of 1 to 3.

R7 of the above silane coupling agent preferably contains a vinyl group and/or a chloro group. Specific silane coupling agents include, but are not limited to, the following.
Bis(3-triethoxysilylpropyl) tetrasulfide, bis(3-triethoxysilylpropyl) trisulfide, bis(3-triethoxysilylpropyl) disulfide, bis(2-triethoxysilylpropyl) tetrasulfide, bis(3 -Trimethoxysilylpropyl) tetrasulfide, bis(2-trimethoxysilylpropyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethoxysilane 3-triethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide Sulfide, 3-trimethoxysilylpropyl benzothiazole tetrasulfide, 3-triethoxysilylpropyl benzothiazole tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, vinyl trichlorosilane, methyl vinyl Dichlorosilane, divinyldichlorosilane, dimethylvinylchlorosilane, chloromethyldimethylvinylsilane, methoxydimethylvinylsilane, trimethoxyvinylsilane, dimethyldivinylsilane, ethoxydimethylvinylsilane, diacetoxymethyldinylsilane, allyloxydimethylvinylsilane, diethoxymethylvinylsilane, bis (Dimethylamino)methylvinylsilane, phenylvinyldichlorosilane, triacetoxyvinylsilane, 3-chloropropylmethyldivinylsilane, diethoxydivinylsilane, dimethylethylmethylketokimvinylsilane, dimethylisobutoxyvinylsilane, triethoxyvinylsilane, methylphenylvinylchlorosilane, Methylphenylvinylsilane, dimethylisopentyloxyvinylsilane, 4-bromophenyldimethylvinylsilane, 3-aminophenoxydimethylvinylsilane, 4-aminophenoxydimethylvinylsilane, dimethylpiperidinomethylvinylsilane, dimethyl-2-[(2-ethoxyethoxy)ethoxy ] Vinylsilane, divinylmethylphenoxysilane, dimethyl-P-anisylvinylsilane, tris(1-methyl) Rubinyloxy) vinylsilane, triisopropoxyvinylsilane, diethoxy-2-piperidinoethoxyvinylsilane, diphenylvinylchlorosilane, 3-dimethylvinylphenyl N,N-diethylcarbomate, triphenoxyvinylsilane, 1,3-divinyl-1,1, 3,3-tetramethyldisiloxane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, 1-(4-methylpiperidinomethyl)-1,1,3,3-tetramethyl -3-Vinyldisiloxane, 1,4-bis(dimethylvinylsilyl)benzene, 1,4-bis(dimethylvinylsiloxy)benzene, 1,3-bis(dimethylvinylsiloxy)benzene, 1,1,3,3 -Tetraphenyl-, 3-divinyldisiloxane, 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7- Tetravinylcyclotetrasiloxane, tetrakis(dimethylvinylsiloxymethyl)methane, 3-chloropropyltrimethoxysilane.

The amount of the silane coupling agent added is preferably 0.2 to 20% by weight, more preferably 5 to 15% by weight, based on the amount of the filler. If the added amount of the silane coupling agent is less than the above range, it may cause scorch. On the other hand, if the amount exceeds the above range, the tensile properties and the elongation may decrease.

The above rubber composition can be obtained by kneading with a mixer such as an ordinary Banbury mixer or kneader.

The polybutadiene according to the present invention can also be used as a modifier for plastics such as high impact polystyrene. That is, the rubber-modified impact-resistant polystyrene resin composition containing the polybutadiene according to the present invention can be produced.

As a method for producing the rubber-modified impact-resistant polystyrene-based resin composition, for example, a method of polymerizing a styrene-based monomer in the presence of a rubber-like polymer is adopted, and a bulk polymerization method or a bulk suspension polymerization method is economical. This is an advantageous method. As the styrene-based monomer, for example, styrene; alkyl-substituted styrene such as α-methylstyrene and p-methylstyrene; halogen-substituted styrene such as chlorostyrene, etc., which are conventionally known for producing rubber-modified impact-resistant polystyrene-based resin composition. One or a mixture of two or more of the styrenic monomers described above is used. Of these, styrene is preferable.

In the production of the rubber-modified impact-resistant polystyrene resin composition, if necessary, in addition to the rubber-like polymer, styrene-butadiene copolymer, ethylene-propylene, ethylene-vinyl acetate, acrylic rubber, etc. The rubber-like polymer may be used in combination in an amount of, for example, 50% by weight or less. Moreover, you may mix the resin composition manufactured by these methods. Further, polystyrene-based resin containing no rubber-modified polystyrene-based resin composition produced by these methods may be mixed.

Explaining the above-mentioned bulk polymerization method with an example, a rubber-like polymer (1 to 25% by weight) is dissolved in a styrene monomer (99 to 75% by weight), and in some cases, a solvent, a molecular weight modifier, a polymerization initiator, etc. Is added to convert the rubbery polymer to particles dispersed in a styrene monomer conversion of 10 to 40%. The rubber phase forms a continuous phase until the rubber particles are generated. Further, the polymerization is continued to undergo a phase conversion (particle forming step) as a dispersed phase as rubber particles to polymerize up to a conversion rate of 50 to 99% to produce a rubber-modified impact-resistant polystyrene resin composition.

Dispersed particles of rubber-like polymer (rubber particles) are particles dispersed in a resin and consist of a rubber-like polymer and a polystyrene resin. The polystyrene-based resin may or may not be graft-bonded to the rubber-like polymer. It is stored. The diameter of the dispersed particles of the rubber-like polymer referred to in the present invention is preferably 0.5 to 7.0 μm (preferably 1.0 to 3.0 μm).

A graft ratio in the range of 150 to 350 can be suitably manufactured. The production may be batch type or continuous type, and is not particularly limited. The raw material solution mainly composed of the styrene-based monomer and the rubber-like polymer is polymerized in the complete mixing type reactor, but as the complete mixing type reactor, the raw material solution maintains a uniform mixed state in the reactor. Any one may be used, and preferable examples include a stirring blade of a type such as a helical ribbon, a double helical ribbon, and an anchor. It is preferable to attach a draft tube to the helical ribbon type stirring blade to further strengthen the vertical circulation in the reactor.

The rubber-modified impact-resistant polystyrene-based resin composition may include an antioxidant, a stabilizer such as an ultraviolet absorber, a release agent, a lubricant, a colorant, various fillers, and various fillers as needed during or after the production. Known additives such as plasticizers, higher fatty acids, organic polysiloxanes, silicone oils, flame retardants, antistatic agents and foaming agents may be added. The rubber-modified impact-resistant polystyrene-based resin composition can be used for various known molded products, but it is excellent in flame resistance, impact resistance, and tensile strength, and therefore suitable for injection molding used in the fields of electrical and industrial applications. It is suitable. For example, it can be used in a wide range of applications such as a color television, a radio-cassette recorder, a word processor, a typewriter, a facsimile, a VTR cassette, a housing of a housing such as a telephone, and home electric appliances/industrial applications.

2. Second invention <<Polybutadiene (2)>>
The second invention relates to the following.
..
[1] A non-halogenated organometallic compound (B1) of the elements of Groups 1, 2, and 13 of the periodic table and a halogenated organometallic compound (B2) of the elements of Groups 1, 2, and 13 of the periodic table are used in combination. The step of polymerizing 1,3-polybutadiene,
When the amount of the component (B1) used is b1 mol and the amount of the component (B2) used is b2 mol,
0.10≦b2/(b1+b2)≦0.60
A method for producing polybutadiene that satisfies the above conditions.
[2] The step of polymerizing the 1,3-polybutadiene is
1,3-Butadiene, water (A), non-halogenated organometallic compound (B1) of elements of Groups 1, 2, and 13 of the periodic table, and halogenation of elements of Groups 1, 2, and 13 of the periodic table A step of mixing with the organometallic compound (B2),
Of the polybutadiene of [1], which comprises a step of mixing the obtained mixture, a cobalt compound (C), an ionic compound (D) of a non-coordinating anion and a cation, and polymerizing 1,3-butadiene. Production method.
[3] The non-halogenated organometallic compound (B1) is a non-halogenated organoaluminum compound, and the halogenated organometallic compound (B2) is a halogenated organoaluminum compound [1] or [2]. The method for producing polybutadiene according to claim 1.
[4] The ionic compound (D) of a nonionic anion and a cation is triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate and 1,1′- The method for producing polybutadiene according to [1] to [3], which comprises at least one member selected from the group consisting of dimethylferrocenium tetrakis(pentafluorophenyl)borate.
[5] Polybutadiene obtained by the method for producing polybutadiene according to [1] to [4].
[6] The ratio of weight average molecular weight to number average molecular weight (Mw/Mn) in terms of polystyrene by GPC is 2.0 to 2.5,
The ratio (Tcp/ML) of the 5 wt% toluene solution viscosity (Tcp) and the Mooney viscosity (ML _{1+4,100° C.} ) is 2.5 to 6.0,
The cis-1,4 bond content in the microstructure analysis is 98.5 mol% or more,
Polybutadiene having a halogen content of 1 to 60 μg/g.
[7] The polybutadiene according to [6], having a Mooney viscosity (ML _{1+4,100° C.} ) of 30 to 100.
[8] The polybutadiene according to [6] or [7], wherein the ratio (Mz/Mw) of the z-average molecular weight (Mz) and the number-average molecular weight (Mw) is 1.60 or more and less than 2.00.
[9] A rubber composition containing the polybutadiene of [5] to [8].
[10] A tire using the rubber composition according to [9].

<Method for producing polybutadiene>
In the present invention, water (A), an organometallic compound (B) of the elements of Groups 1, 2, and 13 of the periodic table, a cobalt compound (C), and an ionic compound (D) of a non-coordinating anion and a cation are included. Polybutadiene can be produced by polymerizing 1,3-butadiene with a catalyst.
The method for producing polybutadiene of the present invention comprises the steps of polymerizing 1,3-polybutadiene,
A non-halogenated organometallic compound of the elements of Groups 1, 2 and 13 of the periodic table (B1) and a halogenated organometallic compound of the elements of Groups 1, 2 and 13 of the periodic table (B2) are used in combination,
When the amount of the component (B1) used is b1 mol and the amount of the component (B2) used is b2 mol,
0.10≦b2/(b1+b2)≦0.60
Meet
Further, in the method for producing polybutadiene of the present invention, the step of polymerizing the 1,3-polybutadiene is carried out in the presence of 1,3-butadiene, with water (A) and an element of Group 1, 2, or 13 of the periodic table. Mixing the non-halogenated organometallic compound (B1) with the halogenated organometallic compound (B2) of the elements of groups 1, 2, and 13 of the periodic table, and the obtained mixture and the cobalt compound (C). And mixing the non-coordinating anion and the cation ionic compound (D) to polymerize 1,3-butadiene.
The elements of Groups 1, 2, and 13 of the Periodic Table are elements of Groups I to III of the Periodic Table in the old IUPAC.

((A) component: water)
As the component (A) water, ion-exchanged water or pure water can be used.

(Component (B): Organometallic compound of Group 1, 2 and 13 elements of the periodic table)
In the present invention, the non-halogenated organometallic compound (B1) of the elements of Groups 1, 2, and 13 of the periodic table is used as the organometallic compound of the elements of Groups 1, 2, and 13 of the periodic table of the component (B), and A halogenated organometallic compound (B2) of Group 1, 2 and 13 elements of the Periodic Table is used in combination. By doing so, the yield of polybutadiene can be significantly improved, and the linearity of the polybutadiene obtained can be increased.

(Component (B1): Non-halogenated organometallic compound of Group 1, 2 and 13 elements of the periodic table)
As the non-halogenated organometallic compound of the elements of Groups 1, 2, and 13 of the periodic table of the component (B1), non-halogenated organolithium compounds, non-halogenated organomagnesium compounds, non-halogenated organoaluminum compounds, etc. are used. .. Of these, non-halogenated organoaluminum compounds are preferable. As the non-halogenated organoaluminum compound, trialkylaluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum; diethylaluminum hydride, diisobutylaluminum hydride, sesquiethylaluminum hydride, etc. Alkyl aluminum hydride is mentioned. The non-halogenated organometallic compounds of the elements of Groups 1, 2, and 13 of the Periodic Table may be used alone or in combination of two or more.

(Component (B2): Halogenated organometallic compound of Group 1, 2 and 13 elements of the periodic table)
As the halogenated organometallic compound of the elements of Groups 1, 2, and 13 of the periodic table of the component (B2), a halogenated organolithium compound, a halogenated organomagnesium compound, a halogenated organoaluminum compound or the like is used. Of these, halogenated organoaluminum compounds are preferable. Examples of the halogenated organoaluminum compound include dialkyl aluminum chlorides such as dimethyl aluminum chloride and diethyl aluminum chloride; dialkyl aluminum bromides such as dimethyl aluminum bromide and diethyl aluminum bromide; alkyl aluminum sesquichlorides such as methyl aluminum sesquichloride and ethyl aluminum sesquichloride; Examples thereof include alkylaluminum sesquibromide and methylaluminum sesquibromide. The halogenated organometallic compounds of Group 1, 2, and 13 elements of the periodic table may be used alone or in combination of two or more.

(Component (C): cobalt compound)
As the cobalt compound as the component (C), a cobalt salt or complex is preferably used. Particularly preferred are cobalt chloride, cobalt bromide, cobalt nitrate, cobalt octylate, cobalt naphthenate, cobalt acetate, cobalt malonate and other cobalt salts, cobalt bisacetylacetonate and trisacetylacetonate, ethyl acetoacetate. Examples thereof include ester cobalt, organic base complexes such as cobalt pyridine complex and picoline complex, and cobalt ethyl alcohol complex. The cobalt compounds may be used alone or in combination of two or more.

(Molar ratio of component (B1) and component (B2))
The blending ratio of the component (B1) and the component (B2) is 0.10≦b2/(b1+b2)≦ when the amount of the component (B1) used is b1 mol and the amount of the component (B2) used is b2 mol. It is important to satisfy 0.60. If the blending ratio of the component (B1) is too low, the yield of polybutadiene will be low, and if the blending ratio of the component (B2) is too high, the linearity of the polybutadiene obtained will be low. The yield of polybutadiene can be significantly improved, and the linearity of the polybutadiene obtained can be increased. b2/(b1+b2) is preferably 0.14 or more, more preferably 0.17 or more, still more preferably 0.20 or more. As for b2/(b1+b2), 0.50 or less is preferable, 0.40 or less is more preferable, and 0.30 or more is further preferable.

(Molar ratio of component (A) to component (D))
The mixing ratios of the components (A) to (D) may be appropriately set according to various conditions. The molar ratio of the component (C) to the component (D) is preferably 1:0.1 to 10, more preferably 1:0.2 to 5. The molar ratio of the component (C) to the component (B) is preferably 1:0.5 to 5000, more preferably 1:5 to 2500. The molar ratio of the component (B) to the component (A) is preferably 1:0.01 to 2, more preferably 1:0.01 to 1.5, and further preferably 1:0.1 to 1.5. ..

(Mixing or adding order of each component)
Regarding the order of mixing or adding each component, first, 1,3-butadiene, water (A), a non-halogenated organometallic compound (B1) of an element of Groups 1, 2, and 13 of the periodic table, and the periodic The halogenated organometallic compound (B2) of Group 1, 2 and 13 elements in the table is mixed (first step). In the first step, in the presence of 1,3-butadiene, water (A), a non-halogenated organometallic compound of an element of Groups 1, 2, and 13 of the periodic table (B1), and a first group of the periodic table It is preferable to mix with a halogenated organometallic compound (B2) of a Group 2 or 13 element. Then, the obtained mixture, the cobalt compound (C), and the ionic compound (D) of a non-coordinating anion and a cation are mixed (second step). In the second step, it is preferable to add the cobalt compound (C) and the ionic compound (D) of a non-coordinating anion and a cation to the obtained mixture. By producing polybutadiene by such a process, the yield of polybutadiene can be significantly improved and the linearity of the obtained polybutadiene can be increased.

In the first step, 1,3-butadiene is polymerized by adding the component (A) and the component (B) (=the component (B1) and the component (B2)) in the presence of 1,3-butadiene. A cocatalyst is formed. The component (A) and the component (B) may be added simultaneously or at intervals, but it is more preferable to add the component (B) after adding the component (A). The order of adding the component (B1) and the component (B2) is arbitrary.

In the first step, it is preferable to add the (A) component and the (B) component in the presence of 1,3-butadiene and then to age. The aging temperature is preferably −50 to 80° C., more preferably −10 to 50° C. The aging time is preferably 0.01 to 24 hours, more preferably 0.05 to 5 hours, and even more preferably 0.1 to 3 hours.

In the second step, the mixture obtained in the first step, the component (C) and the component (D) are mixed to polymerize 1,3-butadiene. In the second step, it is preferable to polymerize 1,3-butadiene by adding the component (C) and the component (D) to the mixture obtained in the first step. The component (C) and the component (D) may be added at the same time or at intervals. In the first step, by adding the components (A) and (B) in the presence of 1,3-butadiene, a cocatalyst for polymerizing 1,3-butadiene is formed. This is because the contact of the components first forms an effective and homogeneous active species.

However, when the component (C) is added before the component (D), it is preferable to add the component (C) and the component (D) at the same time or at intervals of less than 3 minutes, preferably 2 minutes or less. It is more preferable to add at intervals, and it is more preferable to add at intervals of 1 minute or less. If an interval of 3 minutes or more is provided, an inhomogeneous active species is formed and an ultrahigh molecular weight component is produced, and it becomes difficult to obtain a polybutadiene having a desired Mw/Mn. On the contrary, when the component (C) and the component (D) are added at the same time or at intervals of less than 3 minutes, a polybutadiene having a desired Mw/Mn can be obtained, and the fracture strength, abrasion resistance and low loss property can be obtained. It becomes easier to obtain polybutadiene that can improve the balance of

<Polybutadiene>
The polybutadiene according to the present invention obtained by the above production method has a ratio (Mw/Mn) of weight average molecular weight to number average molecular weight of 2.0 to 2.5 in terms of polystyrene by GPC.
The ratio (Tcp/ML) of the 5 wt% toluene solution viscosity (Tcp) and the Mooney viscosity (ML _{1+4,100° C.} ) is 2.5 to 6.0,
The cis-1,4 bond content in the microstructure analysis is 98.5 mol% or more,
The content of halogen is 1 to 60 μg/g.

(Ratio of weight average molecular weight to number average molecular weight (Mw/Mn))
The ratio of polystyrene-reduced weight average molecular weight to number average molecular weight (abbreviated as Mw/Mn) by gel permeation chromatography (GPC) is 2.5 or less, preferably 2.4 or less, and preferably 2.3 or less. Is more preferable. If the value of Mw/Mn is too large, the contents of the ultra-high molecular weight component and the low-molecular weight component increase, and there is a tendency that the physical properties of abrasion resistance, fracture strength, and low loss tend to deteriorate. The value of Mw/Mn is 2.0 or more, preferably 2.1 or more, and more preferably 2.2 or more.

(Z average molecular weight (Mz))
The z-average molecular weight (Mz) is preferably 80.0×10 ⁴ to 150.0×10 ⁴ . When the z-average molecular weight (Mz) is 80.0×10 ⁴ or more, abrasion resistance is further improved. On the other hand, if the z-average molecular weight (Mz) is 150.0×10 ⁴ or less, the workability is further improved. The z-average molecular weight (Mz) is more preferably 90.0×10 ⁴ to 140.0×10 ⁴ , and further preferably 95.0×10 ⁴ to 130.0×10 ⁴ .

(Ratio of z-average molecular weight to weight-average molecular weight (Mz/Mw))
The ratio (Mz/Mw) of the z average molecular weight (Mz) and the weight average molecular weight (Mw) is preferably 1.60 or more and less than 2.00. When Mz/Mw is 1.60 or more, workability is further improved. On the other hand, if Mz/Mw is less than 2.00, wear resistance is further improved. Mz/Mw is more preferably 1.60 to 1.95, further preferably 1.70 to 1.90.

(Tcp/ML)
The ratio (abbreviated as Tcp/ML) of the 5 wt% toluene solution (Tcp) to the Mooney viscosity (ML _{1+4,100° C.} ) is 2.5 to 6.0, preferably 3.0 to 5.5, It is more preferably 4.0 to 5.0. If Tcp/ML is too small, the degree of branching of the molecular chain increases, and wear resistance and low loss tend to decrease. Further, it may be difficult to produce Tcp/ML larger than the above range under the condition of obtaining a desired Mw/Mn.

(Moonie viscosity)
The Mooney viscosity (ML _{1+4,100° C.} ) is preferably 30 to 100, more preferably 40 to 90, and further preferably 50 to 80. If the Mooney viscosity is too high, the processability tends to decrease, and if the Mooney viscosity is too low, the abrasion resistance and low loss property tend to decrease.

(1,4-cis bond content (mol%) in microstructure analysis)
The 1,4-cis bond content in the microstructure analysis is 98.5 mol% or more. When the ratio of the 1,4-cis structure is 98.5 mol% or more, the wear resistance is further improved.

(Halogen content)
The halogen content is 1 to 60 μg/g, preferably 5 to 55 μg/g, more preferably 7 to 50 μg/g, and further preferably 10 to 45 μg/g.

<Rubber composition>
The rubber composition contains the polybutadiene obtained by the production method or the polybutadiene.
Since the embodiment of the rubber composition is the same as the embodiment described in the section of the rubber composition of <<polybutadiene (1)>>, the description thereof will be omitted.

Hereinafter, examples based on the present invention will be specifically described.
1. First invention <<Polybutadiene (1)>>

(Moonie viscosity (ML _1+4,100°C ))
The Mooney viscosity (ML _{1+4,100° C.} ) of polybutadiene was measured according to JIS K6300 using a Mooney viscometer (trade name: SMV-200) manufactured by Shimadzu Corporation for 1 minute at 100° C. and then measured for 4 minutes. ..

(Viscosity of 5 wt% toluene solution (Tcp))
The viscosity (Tcp) of a 5 wt% toluene solution of polybutadiene was measured by dissolving 2.28 g of the polymer in 50 ml of toluene and then measuring the viscosity of a Canon Fenske viscometer No. 400 was used and measured at 25°C. A standard solution for calibrating viscometer (JIS Z8809) was used as the standard solution.

(Stress relaxation time (T80))
The stress relaxation time (T80) of polybutadiene was calculated by the stress relaxation measurement according to ASTM D1646-7. Specifically, under the measurement conditions of ML ₁₊₄ , 100° C. at 100° C. measured according to JIS K6300, the torque when the rotor is stopped (0 seconds) after 4 minutes of measurement is 100%, and the value is 80%. The time (unit: second) until relaxation (that is, until it attenuated to 20%) was measured as stress relaxation time T80.

(Z average molecular weight (Mz), weight average molecular weight (Mw), number average molecular weight (Mn))
The z-average molecular weight (Mz), weight-average molecular weight (Mw) and number-average molecular weight (Mn) of polybutadiene were obtained by gel permeation chromatography (GPC, manufactured by Tosoh Corp.) at a temperature of 40° C. using tetrahydrofuran as a solvent. It was calculated from a molecular weight distribution curve using a calibration curve prepared using standard polystyrene as a standard substance. Note that two KF-805L (trade name) manufactured by Shodex were connected in series to the column, and a suggestive refractometer (RI) was used as a detector.

(Micro structure)
The proportion of the microstructure of the polybutadiene, carried out by infrared absorption spectroscopy using a 0.4 wt% carbon disulfide solution, 740 cm ^-1 (cis), 967 cm ^-1 (trans), 910 cm ^-1 (vinyl) It was calculated from the absorption intensity ratio of.

(Processability)
As an index of the processability of the rubber composition, the Mooney viscosity (ML _{1+4,100° C.} ) was measured by the above method, and the index (INDEX) with Comparative Example 4 as 100 was calculated. The larger the index, the better the workability.

(Low loss)
As an index for the low loss property of the rubber composition, EPO LEXOR 100N (trade name) manufactured by GABO was used, and the temperature was 50° C., the frequency was 16 Hz, and the dynamic strain was measured at a dynamic strain of 0.2%. Was measured, and an index (INDEX) with Comparative Example 4 as 100 was calculated. The larger this index is, the better the low loss property is.

(Abrasion resistance)
As an index of abrasion resistance of the rubber composition, the Lambourn abrasion coefficient was measured at a slip ratio of 10% according to the measuring method defined in JIS K6264, and an index (INDEX) with Comparative Example 4 as 100 was calculated. The larger this index, the better the abrasion resistance.

(Example 1A)
The inside of an autoclave having an internal capacity of 1.5 L was replaced with nitrogen, 550 ml of dehydrated cyclohexane and 350 ml of butadiene were charged, and the butadiene concentration in the mixed solution was set to 4.4M.

The temperature of this mixed solution was adjusted to 25° C., component (A1): water (46 μl, 2.8 mM) was added, and the mixture was stirred at 500 rpm for 30 minutes. Further, 1.2 ml (10.8 mM) of cyclooctadiene (COD), (B1a) component: triethylaluminum (TEA) 2.1 mmol (2.34 mM) and (B1b) component: diethylaluminum chloride (DEAC) 0. 73 mmol (0.81 mM) was added, and one and a half minutes later, the temperature started to rise to 65°C. Five minutes after the addition of the components (B1a) and (B1b), 1.35 ml (6 μM) of a cyclohexane solution (4 mM) of the component (C1): cobalt octenoate (Co(Oct) ₂ ) was added, and after 10 seconds. Component (D): 2.03 ml (9 μM) of a toluene solution (4 mM) of triphenylcarbonium tetrakis(pentafluorophenyl)borate (Ph ₃ CB(C ₆ F ₅ ) ₄ ) was added, and the mixture was added at 65° C. for 10 minutes. Polymerized (first polymerization step). The conversion rate of 1,3-butadiene at the time when the first polymerization step was completed was 35.3%.

The temperature of the obtained mixed solution was set to 65° C., (A2) component: 14.0 μl of water (0.86 mM) and (B2) component: diethylaluminum chloride (DEAC) 1.51 mmol (1.68 mM) were added, The mixture was stirred at 500 rpm for 2 minutes. The temperature was lowered to 60° C., 2.25 ml (10 μM) of a cyclohexane solution (4 mM) of component (C2): cobalt octenoate (Co(Oct) ₂ ) was added, and polymerization was performed at 60° C. for 5 minutes (second polymerization step). ). The conversion rate of 1,3-butadiene at the time when the second polymerization step was completed was 65.4%.

Then, 1.5 ml of an ethanol solution of an antioxidant was added to the obtained mixed solution to stop the polymerization. After depressurizing the inside of the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. Then, the recovered polybutadiene was vacuum dried at 100° C. for 1 hour. Table 1 shows the physical properties of the obtained polybutanediene.

(Example 2A)
The amount of cyclooctadiene (COD) added in the first polymerization step was 1.0 ml (9.0 mM), and the amount of component (A2):water added in the second polymerization step was 6.0 μl (0.37 mM). And the amount of component (B2): diethylaluminum chloride (DEAC) added in the second polymerization step was 0.68 mmol (0.75 mM), and component (C2) added in the second polymerization step: cobalt octenoate (Co Polybutadiene was obtained in the same manner as in Example 1A, except that the amount of the (Oct) ₂ ) cyclohexane solution (4 mM) was 1.35 ml (6 μM). Table 1 shows the monomer conversion rate after each step and the physical properties of the obtained polybutadiene.

(Example 3A)
The amount of cyclooctadiene (COD) added in the first polymerization step was 0.88 ml (7.9 mM), and the amount of component (A2):water added in the second polymerization step was 10.0 μl (0.62 mM). And the amount of component (B2): diethylaluminum chloride (DEAC) added in the second polymerization step was 1.13 mmol (1.25 mM), and the component (C2) added in the second polymerization step: cobalt octenoate (Co Polybutadiene was obtained in the same manner as in Example 1A, except that the amount of the (Oct) ₂ ) cyclohexane solution (12 mM) was 1.05 ml (14 μM). Table 1 shows the monomer conversion rate after each step and the physical properties of the obtained polybutadiene.

(Example 4A)
The inside of an autoclave having an internal volume of 1.5 L was replaced with nitrogen, 450 ml of dehydrated cyclohexane and 450 ml of butadiene were charged, and the butadiene concentration in the mixed solution was adjusted to 5.3M.

The temperature of this mixed solution was adjusted to 25° C., component (A1): water 42 μl (2.6 mM) was added, and the mixture was stirred at 500 rpm for 30 minutes. Furthermore, 1.1 ml (10.0 mM) of cyclooctadiene (COD), (B1a) component: triethylaluminum (TEA) 2.09 mmol (2.32 mM) and (B1b) component: diethylaluminum chloride (DEAC) 0. 69 mmol (0.77 mM) was added, and after 5 minutes, the temperature was raised to 60°C. After heating, 0.90 ml (4 μM) of a cyclohexane solution (4 mM) of component (C1): cobalt octenoate (Co(Oct) ₂ ) and component (D): triphenylcarbonium tetrakis(pentafluorophenyl)borate ( 1.35 ml (6 μM) of a toluene solution (4 mM) of Ph ₃ CB(C ₆ F ₅ ) ₄ ) was simultaneously added, and polymerization was carried out at 60° C. for 20 minutes (first polymerization step). The conversion rate of 1,3-butadiene at the end of the first polymerization step was 27.0%.

The temperature of the obtained mixed solution was adjusted to 60° C., component (B2): diethylaluminum chloride (DEAC) 0.54 mmol (0.60 mM) was added, and the mixture was stirred at 500 rpm for 2 minutes. At 60° C., 1.35 ml (6 μM) of a cyclohexane solution (4 mM) of component (C2): cobalt octenoate (Co(Oct) 2) was added, and polymerization was performed at 60° C. for 20 minutes (second polymerization step). The conversion rate of 1,3-butadiene at the time when the second polymerization step was completed was 42.6%.

Then, 1.5 ml of an ethanol solution of an antioxidant was added to the obtained mixed solution to terminate the polymerization. After depressurizing the inside of the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. Then, the recovered polybutadiene was vacuum dried at 100° C. for 1 hour.

(Example 5A)
The inside of an autoclave having an internal volume of 1.5 L was replaced with nitrogen, 450 ml of dehydrated cyclohexane and 450 ml of butadiene were charged, and the butadiene concentration in the mixed solution was adjusted to 5.3M.

The temperature of the obtained mixed solution was set to 60° C., 1.35 ml (6 μM) of a cyclohexane solution (4 mM) of component (C2): cobalt octenoate (Co(Oct) ₂ ) was added, and polymerization was performed at 60° C. for 20 minutes. (Second polymerization step). The conversion rate of 1,3-butadiene at the end of the second polymerization step was 50.3%.

(Reference example 1)
The first polymerization step was carried out in the same manner as in Example 1A except that the polymerization time was 20 minutes. Then, 1.5 ml of an ethanol solution of an antioxidant was added to the obtained mixed solution to terminate the polymerization. After depressurizing the inside of the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. Then, the recovered polybutadiene was vacuum dried at 100° C. for 1 hour. Table 1 shows the monomer conversion rate after the first polymerization step and the physical properties of the obtained polybutanediene.

(Reference example 2)
The first polymerization step was carried out in the same manner as in Example 2A except that the polymerization time was 20 minutes. Then, 1.5 ml of an ethanol solution of an antioxidant was added to the obtained mixed solution to terminate the polymerization. After depressurizing the inside of the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. Then, the recovered polybutadiene was vacuum dried at 100° C. for 1 hour. Table 1 shows the monomer conversion rate after the first polymerization step and the physical properties of the obtained polybutanediene.

(Reference example 3)
The first polymerization step was carried out in the same manner as in Example 3A except that the polymerization time was 20 minutes. Then, 1.5 ml of an ethanol solution of an antioxidant was added to the obtained mixed solution to terminate the polymerization. After depressurizing the inside of the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. Then, the recovered polybutadiene was vacuum dried at 100° C. for 1 hour. Table 1 shows the monomer conversion rate after the first polymerization step and the physical properties of the obtained polybutanediene.

(Comparative Example 1A)
Table 1 shows the physical properties of commercially available polybutadiene (trade name: BR150L manufactured by Ube Industries).

(Composition evaluation)
Rubber compositions using the polybutadienes of Examples 1A to 5A, Reference Examples 1 to 3 and Comparative Example 1 were produced. Specifically, 30 parts by weight of polybutadiene of Examples 1A to 5A, Reference Examples 1 to 3 and Comparative Example 1 and 70 parts by weight of natural rubber (ML=70) were preliminarily heated to 90° C. and 250 cc of Laboplast mill. And kneaded for 1 minute. Next, 50 parts by weight of carbon black (ISAF, manufactured by Mitsubishi Chemical, trade name: Diablack I), 3 parts by weight of oil (manufactured by H&R, trade name: VivaTec 400), 3 parts by weight of zinc oxide (ZnO#1), stearin. 2 parts by weight of an acid (manufactured by Shin Nippon Rika) and 2 parts by weight of an antioxidant (manufactured by Ouchi Shinko, trade name: Nocrac 6C) were mixed and kneaded for 4 minutes. After a total of 5 minutes had elapsed since the start of the kneading, the kneaded product was taken out from the Labo Plastomill. Next, while winding the mixture taken out around a 6-inch roll and kneading the rolls, 1.5 parts by weight of powdered sulfur as a vulcanizing agent and a vulcanization accelerator (manufactured by Sanshin Chemical Industry Co., Ltd., trade name: Sancellar NS) 1 A rubber composition was obtained by adding parts by weight and mixing for about 5 minutes.

The processability was evaluated by measuring the Mooney viscosity (ML _{1+4,100° C.} ) of the obtained rubber composition. Further, the obtained rubber composition was press-vulcanized at a temperature of 150° C., and tan δ and Lambourn abrasion coefficient of the obtained vulcanized test piece were measured to evaluate low loss property and abrasion resistance. The results are shown in Table 2.

Based on the above results, the INDEX value (workability) of the Mooney viscosity of the rubber composition with respect to the Mooney viscosity (Polymer ML) of polybutadiene, the INDEX value of tan δ at 50° C. (low loss property), and the INDEX value of the Lambourn abrasion coefficient ( Graphs of (wear resistance) are shown in FIGS. 1 to 3, respectively. Compared to Reference Examples 1 to 3 in which only the first polymerization step was performed, Examples 1A to 3A in which the first polymerization step and the second polymerization step were performed based on the commercially available product (Comparative Example 1A) had lower loss property. It can be seen that the workability can be improved while maintaining the same, and the wear resistance is excellent.

2. Second invention <<Polybutadiene (2)>>

(Yield)
The yield of polybutadiene (Yield) was calculated by measuring the weight of the obtained polybutadiene and calculating the ratio (g/L) to the volume of the polymerization solution.

(Weight average molecular weight (Mw), number average molecular weight (Mn))
The weight average molecular weight (Mw) and the number average molecular weight (Mn) of polybutadiene are the standard polystyrene from the molecular weight distribution curve obtained by gel permeation chromatography (GPC, manufactured by Tosoh Corporation) at a temperature of 40° C. using tetrahydrofuran as a solvent. Was calculated by using a calibration curve prepared as a standard substance. Note that two KF-805L (trade name) manufactured by Shodex were connected in series to the column, and a suggestive refractometer (RI) was used as a detector.

(Cis 1,4 bond content (mol%) in microstructure analysis)
The proportion of the microstructure of the polybutadiene, carried out by infrared absorption spectroscopy using a 0.4 wt% carbon disulfide solution, 740 cm ^-1 (cis), 967 cm ^-1 (trans), 910 cm ^-1 (vinyl) It was calculated from the absorption intensity ratio of.

(Halogen content (μg/g))
After dissolving 10 g of polybutadiene in 300 ml of toluene, 100 ml of distilled water was added to the toluene solution. After stirring for 3 hours, toluene and distilled water were separated. The separated distilled water was collected and the chloride ion concentration was quantified using ion chromatography (detector: L-2470 manufactured by Hitachi, column oven: L-2350 manufactured by Hitachi) to determine the halogen content in the polybutadiene. Calculated.

(Example 1B)
The inside of an autoclave having an internal capacity of 1.5 L was replaced with nitrogen, 550 ml of dehydrated cyclohexane and 350 ml of butadiene were charged, and the butadiene concentration in the mixed solution was set to 4.4M.

The temperature of this mixed solution was adjusted to 25° C., component (A): 48 μl (3.0 mM) of water was added, and the mixture was stirred at 500 rpm for 30 minutes. Furthermore, cyclooctadiene (COD) 0.92 ml (8.3 mM), (B1) component: triethylaluminum (TEA) 2.4 mmol (2.67 mM) and (B2) component: diethylaluminum chloride (DEAC) 0. 48 mmol (0.53 mM) was added, and after 1 and a half minutes, the temperature was raised to 65°C. Five minutes after the addition of the components (B1) and (B2), 1.35 ml (6 μM) of a cyclohexane solution (4 mM) of the component (C): cobalt octenoate (Co(Oct) ₂ ) was added, and 10 seconds later. Component (D): 2.03 ml (9 μM) of a toluene solution (4 mM) of triphenylcarbonium tetrakis(pentafluorophenyl)borate (Ph ₃ CB(C ₆ F ₅ ) ₄ ) was added, and the mixture was heated at 65° C. for 20 minutes. Polymerized.

After 30 minutes of polymerization, 1.5 ml of an ethanol solution of an antioxidant was added to stop the polymerization. After depressurizing the inside of the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. Then, the recovered polybutadiene was vacuum dried at 100° C. for 1 hour. The polymerization conditions are shown in Table 3 and the polymerization results are shown in Table 4.

(Examples 2B to 7B, Comparative Examples 1B to 2B)
Polybutadiene was prepared in the same manner as in Example 1B except that the concentrations of the component (A), the types and concentrations of the components (B1) and (B2), and the concentration of COD were changed as shown in Table 3. Manufactured. The polymerization results are shown in Table 3. In Example 7B, ethyl aluminum sesquichloride (EASC) was used as the component (B2) instead of diethyl aluminum chloride (DEAC). In Examples 1B, 3B, 5B and Comparative Example 1B, the polymerization conditions were set so that the Mooney viscosity (ML _{1+4,100° C.} ) of polybutadiene was about 70, and Examples 2B, 4B, 6B, 7B and Comparative Examples were compared. In Example 2B, the polymerization conditions were set so that the polybutadiene had a Mooney viscosity (ML _{1+4,100° C.} ) of about 60.

(Example 8B)
The inside of an autoclave having an internal volume of 1.5 L was replaced with nitrogen, 459 ml of cyclohexane, 339 ml of butadiene and 152 ml of C4 fraction were charged, and the butadiene concentration in the mixed solution was set to 3.8M. The water content of the mixed solution was 0.18 mM.

The temperature of this mixed solution was adjusted to 25° C., 2.69 mmol of component (A): water was added, and the mixture was stirred at 500 rpm for 30 minutes. Further, cyclooctadiene (COD) 9.4 mmol, component (B1): triethylaluminum (TEA) 2.03 mmol, and component (B2): diethylaluminum chloride (DEAC) 1.01 mmol were added, and after 5 minutes. The heating to 65° C. was started. After heating, component (C): cobalt octenoate (Co(Oct) ₂ ) 4.0 μmol and component (D): triphenylcarbonium tetrakis(pentaflurophenyl)borate (Ph ₃ CB(C ₆ F ₅ ) ₄ ) 6.1 μmol was added at the same time and polymerized at 65° C. for 20 minutes.

After 20 minutes of polymerization, 1.5 ml of an ethanol solution containing an antioxidant was added to terminate the polymerization. After depressurizing the inside of the autoclave, ethanol was added to the polymerization solution to recover polybutadiene. Then, the recovered polybutadiene was vacuum dried at 100° C. for 1 hour.

(Example 9B)
Polybutadiene was produced in the same manner as in Example 8B, except that the concentrations of the components (A), (B1) and (B2) were changed as described in Table 3. The polymerization results are shown in Table 4.

(Comparative Example 3B)
The inside of an autoclave having an internal capacity of 1.5 L was replaced with nitrogen, 420 ml of cyclohexane and 530 ml of butadiene were charged, and the butadiene concentration in the mixed solution was adjusted to 6.0 M. The water content of the mixed solution was 0.19 mM.

Example 8B except that the concentration of the component (A), the types and concentrations of the components (B1) and (B2), and the concentration of COD were changed as shown in Table 3 and the polymerization time was 60 minutes. A polybutadiene was produced in the same manner as in. The polymerization results are shown in Table 4.

As shown in FIG. 4 and FIG. 5, graphs of the yield and Tcp/ML with respect to b2/(b1+b2) are shown in FIG. 4 and FIG. 5, respectively. By adjusting b2/(b1+b2) as in the present invention, Tcp/ It can be seen that polybutadiene having a large ML (high linearity) can be produced in a high yield.

The polybutadiene according to the present invention has high linearity and has an improved balance of processability, wear resistance and low loss property. Therefore, by incorporating it into a rubber composition, including a tire, a vibration-proof rubber, a belt, It can be used for hoses, seismic isolation rubbers, rubber crawlers and footwear members.

Claims

A method for producing polybutadiene, which comprises polymerizing 1,3-butadiene in two steps,
A first polymerization step of polymerizing 1,3-butadiene using a cobalt compound (C1), a non-coordinating anion and a ionic compound (D) of a cation;
A method for producing polybutadiene, comprising a second polymerization step in which the mixture obtained in the first polymerization step and a cobalt compound (C2) are mixed to polymerize 1,3-butadiene.
The method for producing polybutadiene according to claim 1, further comprising a step of mixing 1,3-butadiene, water (A1), and an organometallic compound (B1) of an element of Groups 1, 2, and 13 of the periodic table. ..
The conversion of 1,3-butadiene at the end of the first polymerization step is 20 to 50%,
The method for producing polybutadiene according to claim 1 or 2, wherein the final conversion rate of 1,3-butadiene at the time of completion of the second polymerization step is 75% or less.
As the component (B1), a non-halogenated organometallic compound (B1a) of elements of Groups 1, 2, and 13 of the periodic table and a halogenated organometallic compound (B1b) of elements of Groups 1, 2, and 13 of the periodic table The method for producing polybutadiene according to claim 2 or 3, which comprises using.
(B1a) the amount of components and b1 a molar, when the b1 b molar usage (B1b) component,
0.10≦b1 b /(b1 a +b1 b )≦0.60
The method for producing polybutadiene according to claim 4, which satisfies the above condition.
Mooney viscosity (ML 1+4,100° C. ) is 43-80 ,
The ratio (Tcp/ML 1+4,100° C. ) of the 5 wt% toluene solution viscosity (Tcp) and the Mooney viscosity (ML 1+4,100° C. ) is 2.2 to 4.0,
ML 1+4,100° C. When the torque at the end of measurement is set to 100%, the stress relaxation time (T80) until the value decreases by 80% is 2.0 to 7.0 seconds,
The ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) is 2.40 to 4.00,
A polybutadiene having a ratio (Mz/Mw) of z-average molecular weight (Mz) to number-average molecular weight (Mw) of 1.80 to 3.00.
The polybutadiene according to claim 6, which has a 5 wt% toluene solution viscosity (Tcp) of 100 to 300.
The polybutadiene according to claim 6 or 7, which has a weight average molecular weight (Mw) of 40.0×10 4 to 75.0×10 4 .
The polybutadiene rubber according to any one of claims 6 to 8, which has a number average molecular weight (Mn) of 15.0×10 4 to 30.0×10 4 .
A non-halogenated organometallic compound (B1) of the elements of Groups 1, 2, and 13 of the periodic table and a halogenated organometallic compound (B2) of the elements of Groups 1, 2, and 13 of the periodic table are used in combination. , Having a step of polymerizing 3-polybutadiene,
When the amount of the component (B1) used is b1 mol and the amount of the component (B2) used is b2 mol,
0.10≦b2/(b1+b2)≦0.60
A method for producing polybutadiene that satisfies the above conditions.
The step of polymerizing the 1,3-polybutadiene comprises
1,3-Butadiene, water (A), non-halogenated organometallic compound (B1) of elements of Groups 1, 2, and 13 of the periodic table, and halogenation of elements of Groups 1, 2, and 13 of the periodic table A step of mixing with the organometallic compound (B2),
A step of mixing the obtained mixture, a cobalt compound (C), an ionic compound (D) of a non-coordinating anion and a cation, and polymerizing 1,3-butadiene.
The method for producing the polybutadiene according to claim 10.
The non-halogenated organometallic compound (B1) is a non-halogenated organoaluminum compound, and the halogenated organometallic compound (B2) is a halogenated organoaluminum compound. A method for producing the described polybutadiene.
The ionic compound (D) of a nonionic anion and a cation is triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate and 1,1′-dimethylferrose. 13. The method for producing polybutadiene according to any one of claims 1 to 5 or 10 to 12, containing at least one selected from the group consisting of titanium tetrakis(pentafluorophenyl)borate.
Polybutadiene obtained by the method for producing polybutadiene according to any one of claims 1 to 5 or 10 to 13.
The ratio of the weight average molecular weight to the number average molecular weight (Mw/Mn) in terms of polystyrene by GPC is 2.0 to 2.5,
The ratio (Tcp/ML) of the 5 wt% toluene solution viscosity (Tcp) and the Mooney viscosity (ML 1+4,100° C. ) is 2.5 to 6.0,
The cis-1,4 bond content in the microstructure analysis is 98.5 mol% or more,
Polybutadiene having a halogen content of 1 to 60 μg/g.
The polybutadiene according to claim 15, having a Mooney viscosity (ML 1+4,100° C. ) of 30 to 100.
The polybutadiene according to claim 15 or 16, wherein a ratio (Mz/Mw) of z average molecular weight (Mz) and number average molecular weight (Mw) is 1.60 or more and less than 2.00.
A rubber composition containing the polybutadiene according to any one of claims 6 to 9 or 14 to 17.
A tire using the rubber composition according to claim 18.