JP2017082137A - Manufacturing method of modified conjugated diene polymer, modified conjugated diene polymer, rubber composition and tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a modified conjugated diene polymer capable of manufacturing the modified conjugated diene polymer having a high modification rate.SOLUTION: The manufacturing method of a modified conjugated diene polymer includes a polymerization reaction step for polymerization reaction of a conjugated diene monomer in presence of a polymerization catalyst composition to obtain a conjugated diene polymer, a cooling step for cooling a reaction system after the polymerization reaction step and a modification reaction step for modifying the conjugated diene polymer after the cooling step.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a modified conjugated diene polymer, a modified conjugated diene polymer, a rubber composition, and a tire.

In recent years, demands for reducing the fuel consumption of automobiles are becoming more severe in connection with the movement of global carbon dioxide emission regulations due to the social demand for energy saving and the increasing interest in environmental problems. In order to meet such demands, a reduction in rolling resistance has also been demanded for tire performance. As a technique for reducing the rolling resistance of the tire, although a technique by optimizing the tire structure has been studied, the most common technique is to use a material having lower heat generation as the rubber composition.
As the rubber component, high cis-1,4 polybutadiene obtained by polymerization using a catalyst containing a rare earth element is generally a linear polymer having a small branched structure, and has a cis content as compared with conventional high cis polybutadiene. The rubber composition is used as one of the rubber components of the rubber composition (for example, see Patent Document 1) because of its high wear resistance, heat resistance, fatigue resistance, and the like.

  On the other hand, in order to obtain such a rubber composition with low exothermicity, many technical developments have been made so far to improve the dispersibility of the filler used in the rubber composition. Among them, the method of modifying the polymerization active terminal of a diene polymer obtained by anionic polymerization using an organolithium compound with a functional group that interacts with a filler is becoming the most common.

  As such a method, for example, (i) a method in which carbon black is used as a filler and a polymerization active terminal is modified with a tin compound, or (ii) carbon black is similarly used and an amino group is added to the polymerization active terminal. A method of introduction is disclosed (for example, see Patent Document 2).

JP 2013-237868 A JP 2014-58651 A

  However, a modified conjugated diene capable of easily producing a modified conjugated diene polymer having a high modification rate and a specific microstructure (cis-1,4 bond content, vinyl bond content) without going through a complicated process. A method for producing a polymer has not been developed yet, and its development is strongly desired.

An object of the present invention is to provide a method for producing a modified conjugated diene polymer, which can easily produce a modified conjugated diene polymer having a high modification rate under such circumstances.
Another object of the present invention is to provide a modified conjugated diene polymer having a high modification rate. Another object of the present invention is to provide a rubber composition that obtains the effect of the modified conjugated diene polymer of the present invention. It is another object of the present invention to provide a tire that obtains the effect of the modified conjugated diene polymer of the present invention.

As a result of intensive studies to achieve the above-mentioned object, the present inventors have cooled the reaction system containing the conjugated diene polymer, and then modified the conjugated diene polymer to increase the active site, thereby reacting. The inventors have found that the starting point that can be increased is possible, and have completed the present invention.
The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
The method for producing a modified conjugated diene polymer of the present invention comprises a polymerization reaction step of polymerizing a conjugated diene monomer in the presence of a polymerization catalyst composition to obtain a conjugated diene polymer, and a reaction system after the polymerization reaction step. A cooling step for cooling, and a modification reaction step for modifying the conjugated diene polymer after the cooling step.
According to the method for producing a modified conjugated diene polymer of the present invention, a modified conjugated diene polymer having a high modification rate can be easily produced.

Here, as for the manufacturing method of the modified conjugated diene polymer of this invention, it is preferable to cool a reaction system to 50 degrees C or less in the said cooling process.
According to this structure, only a desired reaction can be advanced.

Furthermore, in the method for producing a modified conjugated diene polymer of the present invention, the polymerization catalyst composition preferably contains an organometallic compound represented by the following formula (I). According to this configuration, the polymerization activity can be increased.
YR ¹ _a R ² _b R ³ _c (I)
(In the formula, Y is a metal element selected from the group consisting of elements of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R ¹ and R ² are each of 1 to 10 is a hydrocarbon group or a hydrogen atom, R ³ is a hydrocarbon group having 1 to 10 carbon atoms, provided that R ¹ , R ² and R ³ may be the same or different from each other; Is a Group 1 metal element, a is 1 and b and c are 0, and when Y is a Group 2 or Group 12 metal element, a and b are 1 And when c is 0 and Y is a Group 13 metal element, a, b and c are 1.
Here, it is more preferable that R ¹ , R ² and R ³ are not all the same. According to this configuration, the catalytic activity can be increased.

Furthermore, in the method for producing a modified conjugated diene polymer of the present invention, the conjugated diene monomer is preferably butadiene or isoprene.
According to this structure, various performances, such as a rubber composition and a tire, can be improved.

The modified conjugated diene polymer of the present invention is characterized by being produced by the above-described method for producing a modified conjugated diene polymer.
The modified conjugated diene polymer of the present invention has a high modification rate.

The rubber composition of the present invention is characterized by containing the above-mentioned modified conjugated diene polymer.
According to the rubber composition of the present invention, the effect of the modified conjugated diene polymer of the present invention can be obtained.

The tire of the present invention is manufactured using a rubber composition.
According to the tire of the present invention, the effect of the modified conjugated diene polymer of the present invention can be obtained.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the modified conjugated diene polymer which can manufacture the modified conjugated diene polymer which has a high modification rate easily can be provided.
Moreover, according to the present invention, a modified conjugated diene polymer having a high modification rate can be provided. Furthermore, according to this invention, the rubber composition which obtains the effect of the modified conjugated diene polymer of this invention can be provided. Furthermore, according to this invention, the tire which acquires the effect of the modified conjugated diene polymer of the said invention can be provided.

FIG. 1 is a graph showing an example of a calibration curve for calculating the terminal modification rate of the modified conjugated diene polymer of the present invention.

  Hereinafter, embodiments of the method for producing a modified conjugated diene polymer, the modified conjugated diene polymer, the rubber composition, and the tire of the present invention will be described in detail.

(Method for producing modified conjugated diene polymer)
An example of the method for producing a modified conjugated diene polymer of the present invention (hereinafter also referred to as “example of a method for producing a modified conjugated diene polymer”) includes at least a polymerization reaction step, a cooling step, and a modification reaction step. If necessary, a monomer preparation step, a catalyst system preparation step, and other steps are included.

<Polymerization reaction process>
The polymerization reaction step is a step of obtaining a conjugated diene polymer by subjecting a conjugated diene monomer to a polymerization reaction in the presence of a predetermined polymerization catalyst composition.
Hereinafter, the details of the predetermined polymerization catalyst composition will be described.

-Polymerization catalyst composition (first embodiment)-
The predetermined polymerization catalyst composition (first embodiment) is:
A rare earth element compound (hereinafter also referred to as “component (A-1)”),
Cyclopentadiene or the like (at least one selected from the group consisting of substituted or unsubstituted cyclopentadiene, indene and fluorene) (hereinafter also referred to as “component (B-1)”);
Need to contain.
The predetermined polymerization catalyst composition is:
・ Organic metal compound (hereinafter also referred to as “component (C)”)
・ Aluminoxane compounds (hereinafter also referred to as “component (D)”)
・ Halogen compounds (hereinafter also referred to as “component (E)”)
・ Ionic compounds (hereinafter also referred to as “component (F)”) ”
May further be included.

  The predetermined polymerization catalyst composition (first embodiment) preferably has high solubility in aliphatic hydrocarbons, and is preferably a homogeneous solution in aliphatic hydrocarbons. Here, examples of the aliphatic hydrocarbon include hexane, cyclohexane, pentane, and the like.

And it is preferable that a predetermined polymerization catalyst composition (1st Embodiment) does not contain an aromatic hydrocarbon. Here, examples of the aromatic hydrocarbon include benzene, toluene, xylene, and the like.
Here, “not containing aromatic hydrocarbons” means that the proportion of aromatic hydrocarbons contained in the polymerization catalyst composition is less than 0.1% by weight.

The polymerization catalyst composition (first embodiment) may or may not contain an ionic compound (hereinafter also referred to as “component (F)”) described later. Here, the ionic compound has high solubility in aromatic hydrocarbons and low solubility in hydrocarbons. Therefore, if it is set as the polymerization catalyst composition which does not contain an ionic compound, a modified conjugated diene polymer can be manufactured, reducing further an environmental load and manufacturing cost.
Here, “not containing an ionic compound” means that the proportion of the ionic compound contained in the polymerization catalyst composition is less than 0.01% by weight.

-Polymerization catalyst composition (an example of the first embodiment)-
The predetermined polymerization catalyst composition (an example of the first embodiment)
A rare earth element compound (component (A-1)),
A compound having a cyclopentadiene skeleton (component (B-1-1)),
An ionic compound (hereinafter also referred to as “component (F)”),
Need to contain.
The predetermined polymerization catalyst composition is:
・ Organic metal compound (component (C))
・ Halogen compounds (component (E))
May further be included.

-Polymerization catalyst composition (second embodiment)-
The predetermined polymerization catalyst composition (second embodiment) is:
・ Rare earth element compounds (component (A-1))
Need to contain.
The predetermined polymerization catalyst composition is:
・ Organic metal compound (component (C))
・ Aluminoxane compounds (component (D))
・ Halogen compounds (component (E))
・ Ionic compounds (component (F))
May further be included.

-Polymerization catalyst composition (third embodiment)-
The predetermined polymerization catalyst composition (third embodiment) is:
・ Rare earth element compounds (component (A-1))
-At least one of ionic compounds (component (F)) and halogen compounds (component (E))-Organometallic compounds (component (C))
Need to contain.
The predetermined polymerization catalyst composition is:
Anionic tridentate ligand precursor (hereinafter also referred to as “component (B-2)”)
・ Aluminoxane compounds (component (D))
May further be included.

-Polymerization catalyst composition (fourth embodiment)-
The predetermined polymerization catalyst composition (fourth embodiment) is:
-At least 1 selected from the group consisting of a metallocene complex represented by the following general formula (X), a metallocene complex represented by the following general formula (Y), and a half metallocene cation complex represented by the general formula (Z) It is necessary to include a kind of complex (hereinafter also referred to as “component (A-2)”).

（式中、Ｍは、ランタノイド元素、スカンジウム又はイットリウムを示し、Ｃｐ^Rは、それぞれ独立して無置換もしくは置換インデニルを示し、Ｒ^a〜Ｒ^fは、それぞれ独立して炭素数１〜３のアルキル基又は水素原子を示し、Ｌは、中性ルイス塩基を示し、ｗは、０〜３の整数を示す）

(In the formula, M represents a lanthanoid element, scandium or yttrium, Cp ^R independently represents unsubstituted or substituted indenyl, and R ^{a to} R ^f each independently represents an alkyl having 1 to 3 carbon atoms. A group or a hydrogen atom, L represents a neutral Lewis base, and w represents an integer of 0 to 3).

（式中、Ｍは、ランタノイド元素、スカンジウム又はイットリウムを示し、Ｃｐ^Rは、それぞれ独立して無置換もしくは置換インデニルを示し、Ｘ'は、水素原子、ハロゲン原子、アルコキシド基、チオラート基、アミド基、シリル基又は炭素数１〜２０の炭化水素基を示し、Ｌは、中性ルイス塩基を示し、ｗは、０〜３の整数を示す）

(In the formula, M represents a lanthanoid element, scandium or yttrium, Cp ^R each independently represents an unsubstituted or substituted indenyl group, and X ′ represents a hydrogen atom, a halogen atom, an alkoxide group, a thiolate group, an amide group. , A silyl group or a hydrocarbon group having 1 to 20 carbon atoms, L represents a neutral Lewis base, and w represents an integer of 0 to 3)

（式中、Ｍは、ランタノイド元素、スカンジウム又はイットリウムを示し、Ｃｐ^R'は、無置換もしくは置換シクロペンタジエニル、インデニル又はフルオレニルを示し、Ｘは、水素原子、ハロゲン原子、アルコキシド基、チオラート基、アミド基、シリル基又は炭素数１〜２０の炭化水素基を示し、Ｌは、中性ルイス塩基を示し、ｗは、０〜３の整数を示し、[Ｂ]^-は、非配位性アニオンを示す）

(In the formula, M represents a lanthanoid element, scandium or yttrium, Cp ^R ′ represents an unsubstituted or substituted cyclopentadienyl, indenyl or fluorenyl, and X represents a hydrogen atom, a halogen atom, an alkoxide group or a thiolate group. , An amide group, a silyl group, or a hydrocarbon group having 1 to 20 carbon atoms, L represents a neutral Lewis base, w represents an integer of 0 to 3, and [B] ⁻ represents a non-coordinating group. Anion)

The predetermined polymerization catalyst composition is:
・ Organic metal compound (component (C))
・ Aluminoxane compounds (component (D))
・ Halogen compounds (component (E))
・ Ionic compounds (component (F))
May further be included.

-Rare earth element compound (component (A-1))-
The component (A-1) can be a rare earth element-containing compound or a reaction product of the rare earth element-containing compound and a Lewis base.
In addition, as a rare earth element containing compound, the compound etc. which contain the lanthanoid element comprised from an element of scandium, yttrium, or atomic number 57-71, etc. are mentioned, for example. The lanthanoid elements are specifically lanthanium, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.
In addition, examples of the Lewis base include tetrahydrofuran, diethyl ether, dimethylaniline, trimethylphosphine, lithium chloride, neutral olefins, neutral diolefins, and the like.

  Here, it is preferable that the rare earth element-containing compound or the reaction product of the rare earth element-containing compound and the Lewis base does not have a bond between the rare earth element and carbon. When the reaction product of the rare earth element-containing compound and the Lewis base does not have a rare earth element-carbon bond, the reaction product is stable and easy to handle.

  In addition, the said (A-1) component may be used individually by 1 type, and may be used in combination of 2 or more type.

Here, examples of the component (A-1) include a compound represented by the formula (S1).
M- (NQ ¹ ) (NQ ² ) (NQ ³ ) (S1)
(In the formula, M represents at least one element selected from the group consisting of scandium, yttrium, and lanthanoid elements; NQ ¹ , NQ ^2, and NQ ³ represent amide groups, which may be the same or different. May have 3 MN bonds)

According to the above configuration, the component (A-1) can be a compound having three MN bonds, each bond is chemically equivalent, and the structure of the compound is stable, so that handling is easy. It becomes.
Moreover, according to the said structure, the catalyst activity in a reaction system can further be improved. Therefore, the reaction time can be further shortened and the reaction temperature can be further increased.

As M, gadolinium is particularly preferable from the viewpoint of enhancing catalyst activity and reaction controllability.
Examples of the amide group represented by NQ ¹ , NQ ² and NQ ³ include aliphatic amide groups such as dimethylamide group, diethylamide group and diisopropylamide group; phenylamide group, 2,6-di-tert-butylphenyl Amido group, 2,6-diisopropylphenylamide group, 2,6-dineventylphenylamide group, 2-tert-butyl-6-isopropylphenylamide group, 2-tert-butyl-6-neopentylphenylamide Groups, arylamide groups such as 2-isopropyl-6-neobenzylphenylamide group, 2,4,6-tert-butylphenylamide group; bistrialkylsilylamide groups such as bistrimethylsilylamide group, From the viewpoint of solubility in aliphatic hydrocarbons, bistrimethylsilylamide groups are preferred. Yes. The said amide group may be used individually by 1 type, and may be used in combination of 2 or more type.

-Metallocene complex, etc. (component (A-2))-
The metallocene complex and the like (component (A-2)) are represented by the metallocene complex represented by the general formula (X), the metallocene complex represented by the general formula (Y), and the general formula (Z). It is necessary to include at least one complex selected from the group consisting of half metallocene cation complexes.

  Here, the metallocene complex is a complex compound in which one or more cyclopentadienyl or a derivative thereof is bonded to a central metal.

In the metallocene complex represented by the general formula (X) and the general formula (Y), Cp ^R in the formula is unsubstituted indenyl or substituted indenyl. Cp ^R having an indenyl ring as a basic skeleton can be represented by C ₉ H _7-X R _X or C ₉ H _11-X R _X. Here, X is an integer of 0-7 or 0-11. In addition, each R is preferably independently a hydrocarbyl group or a metalloid group. The hydrocarbyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms. Specific examples of the hydrocarbyl group include a methyl group, an ethyl group, a phenyl group, and a benzyl group. On the other hand, examples of metalloid group metalloids include germyl Ge, stannyl Sn, and silyl Si, and the metalloid group preferably has a hydrocarbyl group, and the hydrocarbyl group that the metalloid group has is the same as the above hydrocarbyl group. is there. Specific examples of the metalloid group include a trimethylsilyl group. Specific examples of the substituted indenyl include 2-phenylindenyl and 2-methylindenyl. The two Cp ^Rs in the general formula (X) and the general formula (Y) may be the same or different from each other.

（式中、Ｒは水素原子、メチル基又はエチル基を示す。） In the half metallocene cation complex represented by the general formula (Z), Cp ^R ′ in the formula
Is unsubstituted or substituted cyclopentadienyl, indenyl or fluorenyl, and among these, unsubstituted or substituted indenyl is preferable. Cp ^{R ′} having a cyclopentadienyl ring as a basic skeleton is represented by C ₅ H _5-X R _X. Where X is 0 to
It is an integer of 5. In addition, each R is preferably independently a hydrocarbyl group or a metalloid group. The hydrocarbyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms. Specific examples of the hydrocarbyl group include a methyl group, an ethyl group, a phenyl group, and a benzyl group. On the other hand, examples of metalloid group metalloids include germyl Ge, stannyl Sn, and silyl Si, and the metalloid group preferably has a hydrocarbyl group, and the hydrocarbyl group that the metalloid group has is the same as the above hydrocarbyl group. is there. Specific examples of the metalloid group include a trimethylsilyl group. Specific examples of Cp ^{R ′} having a cyclopentadienyl ring as a basic skeleton include the following.

(In the formula, R represents a hydrogen atom, a methyl group or an ethyl group.)

In the general formula (Z), Cp ^{R ′} having the indenyl ring as a basic skeleton is defined in the same manner as Cp ^{R in the} general formula (X), and preferred examples thereof are also the same.

In the general formula (Z), Cp ^{R ′} having the fluorenyl ring as a basic skeleton is C ₁₃ H.
_{It can be represented by 9-X} R _X or C ₁₃ H _17-X R _X. Here, X is an integer of 0-9 or 0-17. In addition, each R is preferably independently a hydrocarbyl group or a metalloid group. The hydrocarbyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms. Specific examples of the hydrocarbyl group include a methyl group, an ethyl group, a phenyl group, and a benzyl group. On the other hand, examples of metalloid group metalloids include germyl Ge, stannyl Sn, and silyl Si, and the metalloid group preferably has a hydrocarbyl group, and the hydrocarbyl group that the metalloid group has is the same as the above hydrocarbyl group. is there. Specific examples of the metalloid group include a trimethylsilyl group.

  The central metal M in the general formula (X), the general formula (Y), and the general formula (Z) is a lanthanoid element, scandium, or yttrium. The lanthanoid elements include 15 elements having atomic numbers 57 to 71, and any of these may be used. Preferred examples of the central metal M include samarium Sm, neodymium Nd, praseodymium Pr, gadolinium Gd, cerium Ce, holmium Ho, scandium Sc, and yttrium Y.

The metallocene complex represented by the general formula (X) includes a silylamide ligand [—N (SiR ₃ ) ₂ ]. The R groups contained in the silylamide ligand (R ^{a to} R ^f in the above general formula (X)) are each independently an alkyl group having 1 to 3 carbon atoms or a hydrogen atom. Moreover, it is preferable that at least one of R ^{a to} R ^f is a hydrogen atom. By making at least one of R ^{a to} R ^f a hydrogen atom, the synthesis of the catalyst is facilitated, and the bulk height around silicon is reduced, so that non-conjugated olefin is easily introduced. Furthermore, a methyl group is preferable as the alkyl group.

The metallocene complex represented by the general formula (Y) includes a silyl ligand [—SiX ′ ₃ ]. X ′ contained in the silyl ligand [—SiX ′ ₃ ] represents the general formula (Z) described below.
The group defined similarly to X of this, and a preferable group is also the same.

  In the general formula (Z), X is a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkoxide group, a thiolate group, an amide group, a silyl group, and a hydrocarbon group having 1 to 20 carbon atoms. Here, examples of the alkoxide group include aliphatic alkoxy groups such as a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, and a tert-butoxy group; a phenoxy group and 2,6-dioxy -Tert-butylphenoxy group, 2,6-diisopropylphenoxy group, 2,6-dinepentylphenoxy group, 2-tert-butyl-6-isopropylphenoxy group, 2-tert-butyl-6-neopentylphenoxy group, Examples include aryloxide groups such as 2-isopropyl-6-neopentylphenoxy group, and among these, 2,6-di-tert-butylphenoxy group is preferable.

  In the general formula (Z), examples of the thiolate group represented by X include a thiomethoxy group, a thioethoxy group, a thiopropoxy group, a thio n-butoxy group, a thioisobutoxy group, a thiosec-butoxy group, and a thiotert-butoxy group. Aliphatic thiolate group; thiophenoxy group, 2,6-di-tert-butylthiophenoxy group, 2,6-diisopropylthiophenoxy group, 2,6-dineopentylthiophenoxy group, 2-tert-butyl-6- Arylthiolate groups such as isopropylthiophenoxy group, 2-tert-butyl-6-thioneopentylphenoxy group, 2-isopropyl-6-thioneopentylphenoxy group, 2,4,6-triisopropylthiophenoxy group Among these, 2,4,6-triisopropylthiophenoxy group Preferred.

  In the general formula (Z), examples of the amide group represented by X include aliphatic amide groups such as a dimethylamide group, a diethylamide group, and a diisopropylamide group; a phenylamide group, a 2,6-di-tert-butylphenylamide group, 2,6-diisopropylphenylamide group, 2,6-dineopentylphenylamide group, 2-tert-butyl-6-isopropylphenylamide group, 2-tert-butyl-6-neopentylphenylamide group, 2-isopropyl Arylamide groups such as -6-neopentylphenylamide group, 2,4,6-tert-butylphenylamide group; bistrialkylsilylamide groups such as bistrimethylsilylamide group, among these, bistrimethylsilylamide group Is preferred.

  In the general formula (Z), examples of the silyl group represented by X include trimethylsilyl group, tris (trimethylsilyl) silyl group, bis (trimethylsilyl) methylsilyl group, trimethylsilyl (dimethyl) silyl group, triisopropylsilyl (bistrimethylsilyl) silyl group, and the like. Among these, a tris (trimethylsilyl) silyl group is preferable.

  In the general formula (Z), the halogen atom represented by X may be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, but a chlorine atom or a bromine atom is preferred. Moreover, as a C1-C20 hydrocarbon group which X represents, specifically, a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert- Linear or branched aliphatic hydrocarbon groups such as butyl group, neopentyl group, hexyl group, octyl group; aromatic hydrocarbon groups such as phenyl group, tolyl group, naphthyl group; aralkyl groups such as benzyl group, etc. Others: Examples include hydrocarbon groups containing silicon atoms such as trimethylsilylmethyl group and bistrimethylsilylmethyl group. Among these, methyl group, ethyl group, isobutyl group, trimethylsilylmethyl group and the like are preferable.

  In the above general formula (Z), X is preferably a bistrimethylsilylamide group or a hydrocarbon group having 1 to 20 carbon atoms.

In the general formula (Z), [B] ^- The non-coordinating anion represented by, for example, a tetravalent boron anion. Specific examples of the tetravalent boron anion include tetraphenyl borate, tetrakis (monofluorophenyl) borate, tetrakis (difluorophenyl) borate, tetrakis (trifluorophenyl) borate, tetrakis (tetrafluorophenyl) borate, tetrakis ( Pentafluorophenyl) borate, tetrakis (tetrafluoromethylphenyl) borate, tetra (tolyl) borate, tetra (xylyl) borate, (triphenyl, pentafluorophenyl) borate, [tris (pentafluorophenyl), phenyl] borate, tri Decahydride-7,8-dicarbaoundecaborate and the like can be mentioned, and among these, tetrakis (pentafluorophenyl) borate is preferable.

  The metallocene complex represented by the general formula (X) and the general formula (Y) and the half metallocene cation complex represented by the general formula (Z) are further 0 to 3, preferably 0 to 1. Contains neutral Lewis base L. Here, examples of the neutral Lewis base L include tetrahydrofuran, diethyl ether, dimethylaniline, trimethylphosphine, lithium chloride, neutral olefins, neutral diolefins, and the like. Here, when the complex includes a plurality of neutral Lewis bases L, the neutral Lewis bases L may be the same or different.

  Moreover, the metallocene complex represented by the general formula (X) and the general formula (Y), and the half metallocene cation complex represented by the general formula (Z) may exist as monomers, It may exist as a dimer or higher multimer.

（式中、Ｘ″はハライドを示す。） The metallocene complex represented by the general formula (X) includes, for example, a lanthanoid trishalide, a scandium trishalide or a yttrium trishalide in a solvent, an indenyl salt (for example, potassium salt or lithium salt) and bis (trialkylsilyl). It can be obtained by reacting with an amide salt (eg, potassium salt or lithium salt). In addition, since reaction temperature should just be about room temperature, it can manufacture on mild conditions. The reaction time is arbitrary, but is about several hours to several tens of hours. The reaction solvent is not particularly limited, but is preferably a solvent that dissolves the raw material and the product. For example, toluene may be used. Below, the reaction example for obtaining the metallocene complex represented by the said general formula (X) is shown.

(In the formula, X ″ represents a halide.)

（式中、Ｘ″はハライドを示す。） The metallocene complex represented by the general formula (Y) includes, for example, a lanthanoid trishalide, scandium trishalide, or yttrium trishalide in a solvent, an indenyl salt (for example, potassium salt or lithium salt), and a silyl salt (for example, potassium). Salt or lithium salt). In addition, since reaction temperature should just be about room temperature, it can manufacture on mild conditions. The reaction time is arbitrary, but is about several hours to several tens of hours. The reaction solvent is not particularly limited, but is preferably a solvent that dissolves the raw material and the product. For example, toluene may be used. Below, the reaction example for obtaining the metallocene complex represented by the said general formula (Y) is shown.

(In the formula, X ″ represents a halide.)

The half metallocene cation complex represented by the general formula (Z) can be obtained, for example, by the following reaction.

Here, in the compound represented by the above general formula (IV), M represents a lanthanoid element, scandium or yttrium, and Cp ^{R ′} represents each independently an unsubstituted or substituted cyclopentadienyl, indenyl or fluorenyl. X represents a hydrogen atom, a halogen atom, an alkoxide group, a thiolate group, an amide group, a silyl group, or a hydrocarbon group having 1 to 20 carbon atoms, L represents a neutral Lewis base, and w represents 0 to An integer of 3 is shown. In the ionic compound represented by the general formula [A] ⁺ [B] ⁻ , [A] ⁺ represents a cation, and [B] ⁻ represents a non-coordinating anion.

Examples of the cation represented by [A] ⁺ include a carbonium cation, an oxonium cation, an amine cation, a phosphonium cation, a cycloheptatrienyl cation, and a ferrocenium cation having a transition metal. Examples of the carbonium cation include trisubstituted carbonium cations such as a triphenylcarbonium cation and a tri (substituted phenyl) carbonium cation. The tri (substituted phenyl) carbonyl cation is specifically exemplified by tri (methylphenyl). ) Carbonium cation and the like. Examples of amine cations include trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tripropylammonium cation, and tributylammonium cation; N, N-dimethylanilinium cation, N, N-diethylanilinium cation, N, N- N, N-dialkylanilinium cations such as 2,4,6-pentamethylanilinium cation; dialkylammonium cations such as diisopropylammonium cation and dicyclohexylammonium cation. Examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tri (methylphenyl) phosphonium cation, and tri (dimethylphenyl) phosphonium cation. Among these cations, N, N-dialkylanilinium cation or carbonium cation is preferable, and N, N-dialkylanilinium cation is particularly preferable.

The ionic compound represented by the above general formula [A] ⁺ [B] ⁻ used for the above reaction is a compound selected and combined from the above non-coordinating anions and cations, and N, N-dimethyl Anilinium tetrakis (pentafluorophenyl) borate, triphenylcarbonium tetrakis (pentafluorophenyl) borate and the like are preferable. Similarly, the general formula [A] ⁺ [B] ^- ionic compounds represented by is preferably added from 0.1 to 10 mol per mol of the metallocene complex, more preferably it added about 1 molar. When the half metallocene cation complex represented by the general formula (Z) is used for the polymerization reaction, the half metallocene cation complex represented by the general formula (Z) may be provided as it is in the polymerization reaction system. the compound represented by formula used in the reaction (IV) and the general formula [a] ⁺ [B] ^- provides in separately during the polymerization reaction system is ionic compound represented by, in the reaction system A half metallocene cation complex represented by the general formula (Z) may be formed. Further, by using a combination of the metallocene complex represented by the general formula (X) or the general formula (Y) and the ionic compound represented by the general formula [A] ⁺ [B] ^- The half metallocene cation complex represented by the general formula (Z) can also be formed in the system.

  The structures of the metallocene complex represented by the general formula (X) and the general formula (Y) and the half metallocene cation complex represented by the general formula (Z) are preferably determined by X-ray structural analysis.

--Cyclopentadiene and the like (substituted or unsubstituted, at least one selected from the group consisting of cyclopentadiene, indene and fluorene) (component (B-1))-
The aforementioned component (B-1) is selected from the group consisting of substituted or unsubstituted cyclopentadiene, indene and fluorene, that is, cyclopentadiene, substituted cyclopentadiene compound, indene, substituted indene compound, fluorene and substituted fluorene compound. The
Here, examples of the substituent of the substituted cyclopentadiene compound, the substituted indene compound, and the substituted fluorene compound include a hydrocarbyl group and a metalloid group. The hydrocarbyl group preferably has 1 to 20 carbon atoms, and preferably 1 to 10 carbon atoms. Is more preferable, and it is still more preferable that it is 1-8. Specific examples of the hydrocarbyl group include a methyl group, an ethyl group, a phenyl group, and a benzyl group. On the other hand, examples of metalloid group metalloids include germyl Ge, stannyl Sn, and silyl Si, and the metalloid group preferably has a hydrocarbyl group, and the hydrocarbyl group that the metalloid group has is the same as the above hydrocarbyl group. is there. Specific examples of the metalloid group include a trimethylsilyl group.
The cyclopentadiene and substituted cyclopentadiene compounds have a cyclopentadienyl group. Here, examples of the substituted cyclopentadiene compound include tetramethylcyclopentadiene and pentamethylcyclopentadiene.
The indene and substituted indene compounds have an indenyl group. Here, examples of the substituted indene compound include 2-phenyl-1H-indene, 3-benzyl-1H-indene, 3-methyl-2-phenyl-1H-indene, and 3-benzyl-2-phenyl-1H-indene. 1-benzyl-1H-indene and the like, and 3-benzyl-1H-indene and 1-benzyl-1H-indene are particularly preferable from the viewpoint of reducing the molecular weight distribution.
Moreover, the said fluorene and substituted fluorene compound have a fluorenyl group. Here, as a substituted fluorene compound, trimethylsilylfluorene, 9-methyl-9H-fluorene, etc. are mentioned.
According to the said structure, the conjugated electron which the said (B-1) component can increase can be increased, and the catalyst activity in a polymerization reaction system can be improved further. Therefore, the reaction time can be further shortened and the reaction temperature can be further increased.

  The amount of the component (B-1) used is preferably more than 0 mol with respect to 1 mol of the rare earth element compound (component (A-1)) from the viewpoint of obtaining sufficient catalyst activity, and is 0.5 mol or more. Is more preferably 1 mol or more, and 3 mol or less with respect to 1 mol of the rare earth element compound (component (A-1)) from the viewpoint of suppressing a decrease in catalytic activity. Is preferably 2.5 mol or less, more preferably 2.2 mol or less.

  According to the said structure, the conjugated electron which a cyclopentadiene, indene, or fluorene can provide can be increased, and the catalyst activity in a reaction system can further be improved. Therefore, the reaction time can be further shortened and the reaction temperature can be further increased.

（上記式において、Ｒはアルキル基またはアリール基、Ｙは水素、アルキル基、ハロゲノ基、シリル基、などを示す。）
より具体的には、ビス（２−ジフェニルホスフィノフェニル）アミン等のＰＮＰ配位子が挙げられる。 -Anionic tridentate ligand precursor (component (B-2))-
Examples of the anionic tridentate ligand precursor include compounds represented by the following formula (iii). Such a compound can be produced, for example, with reference to Organometallics, 23, p477784787 (2004).

(In the above formula, R represents an alkyl group or an aryl group, Y represents hydrogen, an alkyl group, a halogeno group, a silyl group, etc.)
More specifically, PNP ligands such as bis (2-diphenylphosphinophenyl) amine are exemplified.

-Organometallic compound (component (C))-
Examples of the component (C) include compounds represented by the formula (I).
YR ¹ _a R ² _b R ³ _c (I)
(In the formula, Y is a metal element selected from the group consisting of elements of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R ¹ and R ² are each of 1 to 10 is a hydrocarbon group or a hydrogen atom, R ³ is a hydrocarbon group having 1 to 10 carbon atoms, provided that R ¹ , R ² and R ³ may be the same or different from each other; Is a Group 1 metal element, a is 1 and b and c are 0, and when Y is a Group 2 or Group 12 metal element, a and b are 1 And when c is 0 and Y is a Group 13 metal element, a, b and c are 1.
Here, from the viewpoint of enhancing the catalytic activity, in the formula (I), it is preferable that R ¹ , R ² and R ³ are not all the same.

Specifically, the component (C) has the formula (C3)
AlR ⁴ R ⁵ R ⁶ (C3)
(In the formula, R ⁴ and R ⁵ are each a hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom, R ⁶ is a hydrocarbon group having 1 to 10 carbon atoms, and R ⁴ , R ⁵ and R ^{6 are} Are preferably the same or different from each other).
Examples of the organoaluminum compound include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-t-butylaluminum, tripentylaluminum, and trihexyl. Aluminum, tricyclohexyl aluminum, trioctyl aluminum; diethyl aluminum hydride, di-n-propyl aluminum hydride, di-n-butyl aluminum hydride, diisobutyl aluminum hydride, dihexyl aluminum hydride, diisohexyl aluminum hydride, Dioctylaluminum hydride, diisooctylaluminum hydride; ethylaluminum dihydride, n-propylaluminium Dihydride, include isobutyl aluminum dihydride and the like, particularly, triethylaluminum, triisobutylaluminum, hydrogenated diethylaluminum, preferably diisobutylaluminum hydride, more particularly, diisobutylaluminum hydride are preferred.
The said organoaluminum compound may be used individually by 1 type, and may be used in combination of 2 or more type.

--Aluminoxane compound (component (D))-
(D) A component is a compound obtained by making an organoaluminum compound and a condensing agent contact.
By using the component (D), the catalytic activity in the polymerization reaction system can be further improved. Therefore, the reaction time can be further shortened, the reaction temperature can be further increased, and the activation and modification rate can be improved.

Here, examples of the organoaluminum compound include trialkylaluminum such as trimethylaluminum, triethylaluminum, and triisobutylaluminum, and mixtures thereof. Particularly, trimethylaluminum, and a mixture of trimethylaluminum and tributylaluminum are preferable.
An example of the condensing agent is water.

As the component (D), for example, the formula (S4)
-(Al (R ¹⁰ ) O) _n- (S4)
(Wherein, R ¹⁰ is a hydrocarbon group having 1 to 10 carbon atoms, wherein the halogen and / or may be substituted with an alkoxy group in some hydrocarbon group; R ¹⁰ is between the repeating units May be the same or different; n is 5 or more)
The aluminoxane represented by these can be mentioned.

The molecular structure of the aluminoxane may be linear or cyclic.
n is preferably 10 or more.
Examples of the hydrocarbon group for R ¹⁰ include a methyl group, an ethyl group, a propyl group, and an isobutyl group, and a methyl group is particularly preferable. The said hydrocarbon group may be used individually by 1 type, and may be used in combination of 2 or more type. As the hydrocarbon group for R, a combination of a methyl group and an isobutyl group is preferable.

The aluminoxane preferably has high solubility in aliphatic hydrocarbons, and preferably has low solubility in aromatic hydrocarbons. For example, aluminoxane marketed as a hexane solution is preferable.
Here, examples of the aliphatic hydrocarbon include hexane and cyclohexane.

In particular, the component (D) has the formula (S5)
_{- (Al (CH 3) x} (i-C 4 H 9) y O) m - ··· (S5)
(Where x + y is 1; m is 5 or more)
It is good also as a modified aluminoxane (henceforth "TMAO") represented by these. As TMAO, the product name: TMAO341 by Tosoh Fine Chemical Co., Ltd. is mentioned, for example.

In addition, the component (D) particularly has the formula (S6)
_{- (Al (CH 3) 0.7} (i-C 4 H 9) 0.3 O) k - ··· (S6)
(Wherein k is 5 or more)
It is good also as a modified aluminoxane (henceforth "MMAO") represented by these. As MMAO, for example, product name: MMAO-3A manufactured by Tosoh Fine Chemical Co., Ltd. may be mentioned.

Further, the component (D) is particularly preferably represented by formula (S7)
− [(CH ₃ ) AlO] _i − (S7)
(Where i is 5 or more)
It may be a modified aluminoxane (hereinafter also referred to as “PMAO”). As PMAO, for example, product name: TMAO-211 manufactured by Tosoh Fine Chemical Co., Ltd. may be mentioned.

  The component (D) is preferably MMAO or TMAO among the MMAO, TMAO, and PMAO from the viewpoint of improving the effect of improving the catalyst activity, and in particular, from the viewpoint of further enhancing the effect of improving the catalyst activity. More preferably.

-Halogen compound (component (E))-
Examples of the component (E) include a halogen-containing compound which is a Lewis acid (hereinafter also referred to as “(E-1) component”), a complex compound of a metal halide and a Lewis base (hereinafter referred to as “(E-2)”. At least one compound selected from the group consisting of an organic compound containing an active halogen (hereinafter also referred to as “component (E-3)”).

These compounds react with a rare earth element-containing compound having an MN bond (for example, (A-1) component, (A-2) component, etc.), or the rare earth element-containing compound and Lewis base To produce a transition metal compound in a state in which electrons are insufficient at the center of the transition metal, and / or the transition metal compound.
By using the component (E), the cis-1,4-bond content of the conjugated diene polymer can be improved.

As the component (E-1), for example, a halogen-containing compound containing an element of Group 3, Group 4, Group 5, Group 6, Group 8, Group 13, Group 14, Group 15 or the like In particular, aluminum halides or organometallic halides are preferred.
Examples of halogen-containing compounds that are Lewis acids include titanium tetrachloride, tungsten hexachloride, tri (pentafluorophenyl) borate, methylaluminum dibromide, methylaluminum dichloride, ethylaluminum dibromide, ethylaluminum dichloride, butylaluminum dibromide. , Butylaluminum dichloride, dimethylaluminum bromide, dimethylaluminum chloride, diethylaluminum bromide, diethylaluminum chloride, dibutylaluminum bromide, dibutylaluminum chloride, methylaluminum sesquibromide, methylaluminum sesquichloride, ethylaluminum sesquichloride, ethylaluminum sesquichloride, aluminum G Examples include bromide, tri (pentafluorophenyl) aluminum, dibutyltin dichloride, tin tetrachloride, phosphorus trichloride, phosphorus pentachloride, antimony trichloride, antimony pentachloride, etc., especially ethyl aluminum dichloride, ethyl aluminum dibromide, diethyl Aluminum chloride, diethylaluminum bromide, ethylaluminum sesquichloride, and ethylaluminum sesquibromide are preferred.
As halogen, chlorine or bromine is preferable.
The halogen-containing compound that is the Lewis acid may be used alone or in combination of two or more.

Examples of the metal halide used for the component (E-2) include beryllium chloride, beryllium bromide, beryllium iodide, magnesium chloride, magnesium bromide, magnesium iodide, calcium chloride, calcium bromide, calcium iodide, Barium chloride, barium bromide, barium iodide, zinc chloride, zinc bromide, zinc iodide, cadmium chloride, cadmium bromide, cadmium iodide, mercury chloride, mercury bromide, mercury iodide, manganese chloride, manganese bromide , Manganese iodide, rhenium chloride, rhenium bromide, rhenium iodide, copper chloride, copper iodide, silver chloride, silver bromide, silver iodide, gold chloride, gold iodide, gold bromide, etc. , Magnesium chloride, calcium chloride, barium chloride, zinc chloride, manganese chloride, copper chloride are preferred, and more particularly, magnesium chloride. Zinc chloride, manganese chloride, copper chloride are preferable.
(E-2) As a Lewis base used for a component, a phosphorus compound, a carbonyl compound, a nitrogen compound, an ether compound, and alcohol are preferable.
For example, tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate, triethylphosphine, tributylphosphine, triphenylphosphine, diethylphosphinoethane, diphenylphosphinoethane, acetylacetone, benzoylacetone, propio Nitrile acetone, valeryl acetone, ethyl acetylacetone, methyl acetoacetate, ethyl acetoacetate, phenyl acetoacetate, dimethyl malonate, diethyl malonate, diphenyl malonate, acetic acid, octanoic acid, 2-ethylhexanoic acid, oleic acid, stearic acid Benzoic acid, naphthenic acid, versatic acid, triethylamine, N, N-dimethylacetamide, tetrahydrofuran, diphenyl ether, 2-ethylhexyl alcohol, olei Alcohol, stearyl alcohol, phenol, benzyl alcohol, 1-decanol, lauryl alcohol, etc. are mentioned, in particular, tri-2-ethylhexyl phosphate, tricresyl phosphate, acetylacetone, 2-ethylhexanoic acid, versatic acid, 2-ethylhexyl alcohol 1-decanol and lauryl alcohol are preferred.
The Lewis base is reacted at a ratio of 0.01 to 30 mol, preferably 0.5 to 10 mol, per mol of the metal halide. When the reaction product with the Lewis base is used, the metal remaining in the polymer can be reduced.

  Examples of the component (E-3) include benzyl chloride.

--Ionic compound (component (F))-
The ionic compound (component (F)) comprises a non-coordinating anion and a cation, and reacts with the rare earth element compound or the Lewis base thereof as the component (A) to react with a cationic transition metal compound. An ionic compound that can generate

  Examples of the non-coordinating anion (for example, tetravalent boron anion) include tetraphenyl borate, tetrakis (monofluorophenyl) borate, tetrakis (difluorophenyl) borate, tetrakis (trifluorophenyl) borate, tetrakis ( Tetrafluorophenyl) borate, tetrakis (pentafluorophenyl) borate, tetrakis (tetrafluoromethylphenyl) borate, tetra (tolyl) borate, tetra (xylyl) borate, (triphenyl, pentafluorophenyl) borate, [tris (pentafluoro Phenyl), phenyl] borate, tridecahydride-7,8-dicarbaoundecaborate, and the like.

On the other hand, examples of the cation include a carbonium cation, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptatrienyl cation, and a ferrocenium cation having a transition metal.
Specific examples of the carbonium cation include a triphenyl carbonium cation, a trisubstituted carbonium cation such as a tri (substituted phenyl) carbonium cation, and the like, and more specifically, a tri (substituted phenyl) carbonyl cation. Includes tri (methylphenyl) carbonium cation, tri (dimethylphenyl) carbonium cation, and the like. Specific examples of ammonium cations include trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tripropylammonium cation, and tributylammonium cation (for example, tri (n-butyl) ammonium cation); N, N-dimethylanilinium N, N-dialkylanilinium cation such as cation, N, N-diethylanilinium cation, N, N-2,4,6-pentamethylanilinium cation; dialkylammonium cation such as diisopropylammonium cation and dicyclohexylammonium cation, Etc.
Specific examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tri (methylphenyl) phosphonium cation, and tri (dimethylphenyl) phosphonium cation.

Therefore, as the ionic compound (component (F)), a compound selected from the above-mentioned non-coordinating anions and cations is preferably combined. Specifically, N, N-dimethylanilinium tetrakis (pentafluorophenyl) ) Borate, triphenylcarbonium tetrakis (pentafluorophenyl) borate and the like are preferable.
In addition, these ionic compounds (component (F)) can be used singly or in combination of two or more. In addition, it is preferable that it is 0.1-10 times mol with respect to (A) component, and, as for content of the ionic compound in the said 1st polymerization catalyst composition, it is still more preferable that it is about 1 time mol.

  Hereinafter, it describes about the weight ratio between each component of an example polymerization catalyst composition.

  The ratio of the component (B-1) (the compound having a cyclopentadiene skeleton) in moles to the component (A-1) (rare earth element compound) is preferably more than 0 from the viewpoint of obtaining sufficient catalytic activity, and is 0.5 or more. Is more preferably 1, or more, particularly preferably 3 or less, more preferably 2.5 or less, and particularly preferably 2.2 or less from the viewpoint of suppressing a decrease in catalyst activity.

  From the viewpoint of improving the catalytic activity in the reaction system, the ratio of the component (C) (organometallic compound) in moles to the component (A-1) is preferably 1 or more, more preferably 5 or more, and the catalytic activity in the reaction system. From the viewpoint of suppressing the decrease, 50 or less is preferable, 30 or less is more preferable, and specifically, about 10 is preferable.

  From the viewpoint of improving the catalytic activity in the reaction system, the ratio of aluminum in the component (D) (aluminoxane) to the mole of the rare earth element in the component (A-1) is preferably 10 or more, more preferably 100 or more, From the viewpoint of suppressing a decrease in catalyst activity in the reaction system, 1000 or less is preferable, and 800 or less is more preferable.

From the viewpoint of improving the catalytic activity, the ratio of (E) component (halogen compound) to (A-1) component is preferably 0 or more, more preferably 0.5 or more, and particularly preferably 1.0 or more, (E) 20 or less are preferable and 10 or less are more preferable from a viewpoint of maintaining the solubility of a component and suppressing the fall of catalyst activity.
Therefore, according to the said range, the effect which improves the cis-1, 4- bond content of a conjugated diene polymer can be heightened.

-Conjugated diene monomer-
The conjugated diene monomer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include 1,3-butadiene, isoprene, 1,3-pentadiene, 2-ethyl-1,3-butadiene, 2 , 3-dimethylbutadiene (2,3-dimethyl-1,3-butadiene), 2-methylpentadiene, 4-methylpentadiene, 2,4-hexadiene, 1,3-hexadiene, and the like. These may be used alone or in combination of two or more.
Among these, 1,3-butadiene and isoprene are preferable from the viewpoint of improving various performances such as a rubber composition and a tire.

  The solvent that can be used in the polymerization reaction step is not particularly limited as long as it is inactive in the polymerization reaction, and can be appropriately selected according to the purpose. For example, n-hexane, cyclohexane, aromatic hydrocarbon ( Benzene, toluene, xylene, etc.), and mixtures thereof.

In the polymerization reaction step, a well-known method in the technical field such as a solution polymerization method, a suspension polymerization method, a liquid phase bulk polymerization method, an emulsion polymerization method, a gas phase polymerization method, and a solid phase polymerization method can be used.
There is no restriction | limiting in particular as reaction temperature in the said polymerization reaction process, Although it can select suitably according to the objective, -100-300 degreeC is preferable, 0-200 degreeC is more preferable, 25-120 degreeC is especially preferable. . In addition, there exists a possibility that cis-1, 4- selectivity may fall at high temperature, and there exists a possibility that reaction rate may fall at low temperature.
There is no restriction | limiting in particular as reaction pressure in the said polymerization reaction process, According to the objective, it can select suitably, For example, it can be set as a normal pressure. At high pressure, the monomer (monomer) may not be sufficiently taken into the polymerization reaction system, and at low pressure, the reaction rate may decrease.
There is no restriction | limiting in particular as reaction time in the said polymerization reaction process, According to the objective, it can select suitably, For example, it can be set as 0.5 to 3 hours.

-Conjugated diene polymer-
The cis-1,4-bond content of the conjugated diene polymer is not particularly limited and may be appropriately selected depending on the purpose. It is preferably 95% or more, more preferably 97% or more, and 98% or more. Particularly preferred. The higher the cis-1,4-bond content of the conjugated diene polymer, the higher the elongation crystallinity of the conjugated diene polymer, and the higher the elasticity of the conjugated diene polymer.
The trans-1,4-bond content of the conjugated diene polymer is not particularly limited and may be appropriately selected depending on the purpose. It is preferably less than 5%, more preferably less than 3%, and more preferably less than 1%. Particularly preferred. As the trans-1,4-bond content of the conjugated diene polymer is lower, the elongation crystallinity of the conjugated diene polymer can be increased, and the elasticity of the conjugated diene polymer can be increased.
The 1,2-vinyl bond content of the conjugated diene polymer is not particularly limited and may be appropriately selected depending on the purpose. It is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less. preferable. The lower the 1,2-vinyl bond content of the conjugated diene polymer, the higher the elongation crystallinity of the conjugated diene polymer and the higher the elasticity of the conjugated diene polymer.
The 3,4-vinyl bond content of the conjugated diene polymer is not particularly limited and may be appropriately selected depending on the purpose. It is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less. preferable. As the 3,4-vinyl bond content of the conjugated diene polymer is lower, the elongation crystallinity of the conjugated diene polymer can be increased, and the elasticity of the conjugated diene polymer can be increased.

There is no restriction | limiting in particular as a number average molecular weight (Mn) of the said conjugated diene polymer, Although it can select suitably according to the objective, 100,000 or more are preferable and 200,000 or more are more preferable.
There is no restriction | limiting in particular as molecular weight distribution (Mw / Mn) of the said conjugated diene polymer, Although it can select suitably according to the objective, 3.0 or less are preferable and 2.5 or less are more preferable.

<Cooling process>
The cooling step is a step of cooling the reaction system after the polymerization reaction step.
The said reaction system means the reaction system after a polymerization reaction process, and contains a conjugated diene polymer and a polymerization catalyst composition at least, and contains a solvent as needed.
The cooling in the cooling step is not particularly limited as long as the temperature of the reaction system is lowered, and can be appropriately selected according to the purpose.
There is no restriction | limiting in particular as the temperature of the temperature-reduced reaction system, Although it can select suitably according to the objective, 50 degrees C or less is preferable, 40 degrees C or less is more preferable, 30 degrees C or less is especially preferable. The temperature of the lowered reaction system is preferably as low as possible, but is preferably around room temperature in terms of production cost.
There is no restriction | limiting in particular as cooling time in the said cooling process, Although it can select suitably according to the objective, 5 minutes are preferable. The cooling time is preferably as long as possible.
There is no restriction | limiting in particular as a temperature fall rate in the said cooling process, Although it can select suitably according to the objective, 1-10 degreeC / min is preferable.

<Modification reaction process>
The modification reaction step is a step of modifying the conjugated diene polymer after the cooling step.
There is no restriction | limiting in particular as a modifier | denaturant used in the said modification | reformation reaction process, According to the objective, it can select suitably, For example, 4,4'-bis (diethylamino benzophenone), 2-cyanopyridine, 3-methyl-2 -Cyanopyridine, etc. can be mentioned.
There is no restriction | limiting in particular as reaction temperature in the said modification | reformation reaction process, Although it can select suitably according to the objective, 50-150 degreeC is preferable, 65-95 degreeC is more preferable, and 70-90 degreeC is especially preferable. In addition, there exists a possibility that a polymer may deteriorate at high temperature, and there exists a possibility that reaction rate may fall at low temperature.
There is no restriction | limiting in particular as reaction pressure in the said modification | denaturation reaction process, According to the objective, it can select suitably, For example, it can be set as a normal pressure.
There is no restriction | limiting in particular as reaction time in the said modification | reformation reaction process, According to the objective, it can select suitably, For example, it can be set as 0.5 to 1.5 hours.
In addition, as long as the modification | denaturation reaction is made | formed after cooling, the injection | throwing-in timing of the said modifier may be anytime.

<Monomer preparation step>
The monomer preparation step is a step of preparing the conjugated diene monomer described above as a monomer.

<Catalyst system preparation process>
The catalyst system preparation step is a step of preparing the predetermined polymerization catalyst composition described above.

Reagents used in the above steps (polymerization reaction step, modification reaction step, monomer preparation step, catalyst system preparation step) may be used without a solvent or together with a solvent suitable for each reagent.
In each of the above steps, the reagent and the solvent are preferably used after appropriately performing purification operations such as distillation, degassing, and lyophilization.
Moreover, it is preferable that each said process, especially a catalyst system preparation process, a polymerization reaction process, and a modification | denaturation reaction process are performed in inert gas atmosphere, such as nitrogen gas and argon gas.

  The production method of the copolymer of the present invention is not limited to the production method of the above example. For example, in the production method of the above example, cyclopentadiene in a predetermined polymerization catalyst composition (first embodiment), etc. May be added in the polymerization reaction step without being included in the polymerization catalyst composition in the catalyst system preparation step.

(Modified conjugated diene polymer)
An example modified conjugated diene polymer of the present invention (hereinafter also referred to as “an example modified conjugated diene polymer”) is produced by the method for producing an example modified conjugated diene polymer of the present invention.
According to the conjugated diene-derived portion in the modified conjugated diene polymer of one example, since it has a very high cis-1,4-bond content, a copolymer rich in elasticity can be provided, and as a rubber component in a rubber composition It can be used suitably.

The cis-1,4-bond content of the conjugated diene-derived moiety in the modified conjugated diene polymer of one example is not particularly limited and can be appropriately selected according to the purpose, preferably 95% or more, and 97% or more. More preferred is 98% or more. The higher the cis-1,4-bond content of the conjugated diene-derived moiety in the modified conjugated diene polymer, the higher the elongation crystallinity of the modified conjugated diene polymer. Elasticity can be increased.
The trans-1,4-bond content of the conjugated diene-derived moiety in the modified conjugated diene polymer is not particularly limited and may be appropriately selected depending on the purpose. It is preferably less than 5%, more preferably less than 3%. Preferably, less than 1% is particularly preferable. The lower the trans-1,4-bond content of the conjugated diene-derived portion in the modified conjugated diene polymer, the higher the stretched crystallinity of the modified conjugated diene polymer, and the higher the elasticity of the copolymer. Can be increased.
The 1,2-vinyl bond content of the conjugated diene-derived moiety in the modified conjugated diene polymer is not particularly limited and can be appropriately selected according to the purpose, preferably 5% or less, more preferably 3% or less. 1% or less is particularly preferable. The lower the value of the 1,2-vinyl bond content of the conjugated diene-derived portion in the modified conjugated diene polymer, the higher the elongation crystallinity of the modified conjugated diene polymer, and the elasticity of the modified conjugated diene polymer. Can be increased.
The 3,4-vinyl bond content of the conjugated diene-derived portion in the modified conjugated diene polymer is not particularly limited and can be appropriately selected according to the purpose, preferably 5% or less, more preferably 3% or less. 1% or less is particularly preferable. As the 3,4-vinyl bond content of the conjugated diene-derived portion in the modified conjugated diene polymer is lower, the stretched crystallinity of the modified conjugated diene polymer can be increased, and the elasticity of the modified conjugated diene polymer is increased. Can be increased.

There is no restriction | limiting in particular as a number average molecular weight (Mn) of the said modified conjugated diene polymer, Although it can select suitably according to the objective, 100,000 or more are preferable and 200,000 or more are more preferable.
There is no restriction | limiting in particular as molecular weight distribution (Mw / Mn) of the said modified conjugated diene polymer, Although it can select suitably according to the objective, 3.0 or less are preferable and 2.5 or less are more preferable.

(Rubber composition)
An example rubber composition of the present invention (hereinafter also referred to as “example rubber composition”) needs to contain the modified conjugated diene polymer of one example of the present invention. Here, the modified conjugated diene polymer of an example of the present invention can be a rubber component.
The rubber composition of one example may also contain a rubber component other than the modified conjugated diene polymer of the above example, and a filler, an anti-aging agent, a softening agent, stearic acid, zinc white, a vulcanization accelerator, a vulcanizing agent. , Oil, sulfur and the like.
An example rubber composition can be produced by methods well known to those skilled in the art.

(tire)
An example tire of the present invention (hereinafter, also referred to as “example tire”) needs to be manufactured using the example rubber composition of the present invention. Every member of an example tire may be manufactured using an example rubber composition.
An example tire can be manufactured by methods well known to those skilled in the art.

  It should be noted that rubber products other than tires such as footwear, belts, and flooring materials can also be manufactured using an example rubber composition.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to the following Example at all.

(Production of modified conjugated diene polymer)
A modified conjugated diene polymer was produced according to the following.

Example 1
A sufficiently dried 2 L pressure resistant stainless steel reactor was purged with nitrogen, and 655 g of a hexane solution containing 150 g of 1,3-butadiene was added. On the other hand, bis (2-phenylindenyl) gadolinium bis (dimethylsilylamide) [(2-PhC ₉ H ₆ ) ₂ GdN (SiHMe ₂ ) ₂ ] (( Component A-2)) 94.5 μmol and 2.84 mmol of diisobutylaluminum hydride (component (C)) were added, and these were dissolved in 65 mL of n-hexane. In this glass container, 94.5 μmol of N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate [Me ₂ NHPhB (C ₆ F ₅ ) ₄ ] ((F) component), diethyl aluminum chloride ( (E-1) component) 189 μmol was added to obtain a charged catalyst solution (polymerization catalyst composition). Thereafter, the catalyst solution was taken out from the glove box, an amount of catalyst solution of 90 μmol in terms of gadolinium was added to the monomer solution, and polymerization was performed at 80 ° C. for 60 minutes. Thereafter, the temperature of the reaction system was lowered to 35 ° C., 0.01 mol of 4,4′-bis (diethylaminobenzophenone) (DEAB) as a denaturant was added, and reacted at 50 ° C. for 1 hour. Then, 1.5 mL of 5% by weight isopropanol solution of 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol) (manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., product name: NOCRACK NS-5) was added. The reaction was stopped, and the modified conjugated diene polymer was further separated with a large amount of isopropanol (IPA), followed by vacuum drying at 60 ° C. to obtain a modified polymer A. The yield of the obtained modified polymer A was 148 g.

(Example 2)
In Example 1, “the point of using isoprene instead of 1,3-butadiene” and “N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate [Me ₂ NHPhB (C ₆ F ₅ ) ₄ ] The catalyst solution was the same as in Example 1 except that MMAO (manufactured by Tosoh Finechem, product name: MMAO-3A) (component (D))) 6.26 ml was used instead of (component (F)). Preparation of (polymerization catalyst composition), polymerization reaction and modification reaction were carried out to obtain modified polymer B (yield: 145 g).

(Example 3)
In Example 1, “the point where 2-cyanopyridine was used instead of 4,4′-bis (diethylaminobenzophenone) (DEAB) as a modifier” and ““ the reaction system was cooled to 35 ° C. and modified. Instead of “adding an agent and reacting at 50 ° C. for 1 hour”, except for “the temperature of the reaction system was lowered to 50 ° C., a denaturant was added and reacted at 50 ° C. for 1 hour”, and Similarly, preparation of a catalyst solution (polymerization catalyst composition), polymerization reaction and modification reaction were carried out to obtain a modified polymer C (yield: 148 g).

Example 4
In Example 1, instead of “lowering the reaction system to 35 ° C., adding a denaturant and reacting at 50 ° C. for 1 hour”, “cooling the reaction system to 60 ° C. and introducing the denaturant, The modified polymer D was obtained (yield: 148 g) by preparing a catalyst solution (polymerization catalyst composition), carrying out a polymerization reaction and a modification reaction in the same manner as in Example 1 except that the reaction was carried out for 1 hour.

(Example 5)
A sufficiently dried 2 L pressure resistant stainless steel reactor was purged with nitrogen, and 655 g of a hexane solution containing 150 g of 1,3-butadiene was added. On the other hand, in a glove box under a nitrogen atmosphere, trisbistrimethylsilylamidogadolinium (Gd [N (SiMe ₃ ) ₂ ] ₃ ) (component (A-1)) 94.5 μmol, 1-benzylindene ( 1-Benzyl-1H-indene) (component (B-1)) 189 μmol and diisobutylaluminum hydride (component (C)) 2.84 mmol were added, and these were dissolved in 65 mL of hexane. Then, 6.26 ml of MMAO (manufactured by Tosoh Finechem, product name: MMAO-3A) (component (D))) was added to this glass container, and further, diethylaluminum chloride (component (E-1)) 189 μmol. Was added to obtain a charged catalyst solution (polymerization catalyst composition). Thereafter, the catalyst solution was taken out from the glove box, an amount of catalyst solution of 90 μmol in terms of gadolinium was added to the monomer solution, and polymerization was performed at 80 ° C. for 60 minutes. Thereafter, the temperature of the reaction system was lowered to 35 ° C., 4,4′-bis (diethylaminobenzophenone) (DEAB) as a denaturing agent was added, and the mixture was reacted at 80 ° C. for 1 hour. Then, 1.5 mL of 5% by weight isopropanol solution of 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol) (manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., product name: NOCRACK NS-5) was added. The reaction was stopped, and the modified conjugated diene polymer was separated with a large amount of isopropanol (IPA), followed by vacuum drying at 60 ° C. to obtain a modified polymer E. The yield of the obtained modified polymer E was 145 g.

(Example 6)
In Example 5, “Points using indene instead of 1-benzylindene”, “Points using 2-cyanopyridine instead of 4,4′-bis (diethylaminobenzophenone) (DEAB) as a modifier” And the catalyst as in Example 5 except that, instead of “adding a modifier and reacting at 50 ° C. for 1 hour”, “adding a modifier and reacting at 35 ° C. for 1 hour” Preparation of the solution (polymerization catalyst composition), polymerization reaction and modification reaction were carried out to obtain a modified polymer F (yield: 148 g).

(Example 7)
In Example 5, except “the point using 2-phenylindene instead of 1-benzylindene” and “the point where the reaction system was cooled to 50 ° C. instead of lowering the reaction system to 35 ° C.” Preparation of a catalyst solution (polymerization catalyst composition), polymerization reaction and modification reaction were carried out in the same manner as in Example 5 to obtain a modified polymer G (yield: 140 g).

(Example 8)
In Example 5, “Points using isoprene instead of 1,3-butadiene”, “Points using 47 μmol of bis (2-diphenylphosphinophenyl) amine (PNP ligand) instead of 1-benzylindene ”And“ MMAO (manufactured by Tosoh Finechem, product name: MMAO-3A) (component (D)) ”, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate [Me ₂ NHPhB (C ₆ F ₅ ) ₄ ] (component (F)) Except for the point of using 94.5 μmol ”, the preparation of the catalyst solution (polymerization catalyst composition), the polymerization reaction and the modification reaction were carried out in the same manner as in Example 5 to obtain H was obtained (yield: 146 g).

Example 9
In Example 5, N, N- in place of “Points using indene instead of 1-benzylindene”, “MMAO (manufactured by Tosoh Finechem, product name: MMAO-3A) (component (D))) “Dimethylanilinium tetrakis (pentafluorophenyl) borate [Me ₂ NHPhB (C ₆ F ₅ ) ₄ ] (component (F)) using 94.5 μmol mL” and ““ Introducing a modifier and adding 1% at 80 ° C. Preparation of a catalyst solution (polymerization catalyst composition), polymerization reaction, and modification reaction in the same manner as in Example 5 except that, instead of “reacting for a time”, “the modifier was added and reacted at 60 ° C. for 1 hour” And modified polymer I was obtained (yield: 146 g).

(Comparative Example 1)
In Example 1, instead of “after performing the polymerization at 80 ° C. for 60 minutes, the reaction system is cooled to 35 ° C., the modifier is added, and the reaction is performed at 50 ° C. for 1 hour” instead of “80 ° C. for 60 minutes” After the polymerization, the temperature of the reaction system was not lowered, but the modifier was added as it was and reacted at 80 ° C. for 1 hour ”and“ N, N-dimethylanilinium tetrakis (pentafluorophenyl) Instead of borate [Me ₂ NHPhB (C ₆ F ₅ ) ₄ ] (component (F)) ”,“ MMAO (manufactured by Tosoh Finechem, product name: MMAO-3A) (component (D))) ”6.26 ml The modified polymer J was obtained in the same manner as in Example 1 except that the catalyst solution (polymerization catalyst composition) was prepared, and the polymerization reaction and the modification reaction were performed (yield: 148 g).

(Comparative Example 2)
In Example 1, instead of “after performing the polymerization at 80 ° C. for 60 minutes, the reaction system is cooled to 35 ° C., the modifier is added, and the reaction is performed at 50 ° C. for 1 hour” instead of “80 ° C. for 60 minutes” After the polymerization, the temperature of the reaction system was not lowered, but the modifier was added as it was and reacted at 80 ° C. for 1 hour ”,“ Bis (2-phenylindenyl) gadolinium bis (dimethylsilylamide) ” Instead of using [(2-PhC ₉ H ₆ ) ₂ GdN (SiHMe ₂ ) ₂ ] (component (A-2)), “trisbistrimethylsilylamidogadolinium (Gd [N (SiMe ₃ ) ₂ ] ₃ ) ( (A-1) component) points using 94.5 μmol and 3-benzylindene (component (B-1) 2.84 mmol) ”and“ N, N-dimethylanilinium tetrakis (pentafluorophenyl) Rate _{[Me 2 NHPhB (C 6 F} 5) 4] ((F) component) instead MMAO of: using (Tosoh Finechem Corporation, product name MMAO-3A) ((D) component)) 6.26Ml Except for “point”, the preparation of the catalyst solution (polymerization catalyst composition), the polymerization reaction and the modification reaction were carried out in the same manner as in Example 1 to obtain a modified polymer K (yield: 145 g).

  Details of the preparation of the polymerization catalyst composition and the production of the conjugated diene polymer in each Example and Comparative Example are shown in Table 1-1 and Table 1-2.

(Analysis of modified conjugated diene polymer)
About each obtained said polymer, the analysis of (1)-(3) was conducted below.
(1) Analysis of microstructure (cis-1,4-bond content, vinyl bond content) For each of the obtained polymers, an NMR spectrum was obtained using NMR (manufactured by Bruker, AVANCE 600). Peak obtained by measurement of ¹ H-NMR and ¹³ C-NMR ( ¹ H-NMR: δ 4.6-4.8 (= CH _{2 of} 3,4-vinyl unit), 5.0-5.2 (-CH = 1,4-unit), ¹³ C-NMR: δ 23.4 (1,4-cis unit), 15.9 (1,4-trans unit), 18.6 (3,4- The amount of cis-1,4 bond (%) was calculated from the integration ratio of the unit)).
(2) Analysis of number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) Gel permeation chromatography (GPC) (GPC apparatus: manufactured by Tosoh Corporation, HLC-8220GPC; column: manufactured by Tosoh Corporation, TSKgel GMH _XL- 2) The number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) in terms of polystyrene of each modified polymer were calculated using a monodisperse polystyrene as a reference by a main detector (detector: differential refractometer (RI)). The measurement temperature was 40 ° C. and the elution solvent was THF.
(3) Terminal modification rate (%)
Here, the terminal modification rate will be described in detail with reference to FIG.
The vertical axis indicates the value of UV / RI obtained by gel permeation chromatography (GPC) measurement. UV indicates a peak area value obtained from the UV absorbance caused by the modifier that has reacted with the polymer, and RI indicates a peak area value obtained from the differential refractive index (RI) of the polymer itself.
The horizontal axis indicates a value of (1 / Mn) × 10 ³ , and Mn is the absolute molecular weight (number average molecular weight). In FIG. 1, LowCisBR is polymerized by anionic polymerization with a Li-based catalyst and modified with a modifier 4, 4′-bis (diethylaminobenzophenone) (DEAB), and has three types of UV / RI of different molecular weights Mn. Values are plotted and can be approximated as a straight line. In the case of anionic polymerization, since it is 100% modified, it is represented by A as shown in the following formula, assuming that UV / RI of LowCisBR is 100%.
UV (Li-Br) / RI (Li-Br) = A
On the other hand, using a catalyst containing a lanthanum-based rare earth element (Nd) -containing compound that is coordination polymerization, the high CisBR modified with DEAB is plotted with five types of UV / RI values having different molecular weights Mn. It can be approximated as a straight line. In the case of coordination polymerization, there is a portion that is not living during polymerization, and it is difficult to modify 100%. When the UV / RI of HighCisBR is represented by B as shown in the following formula,
UV (Nd-Br) / RI (Nd-Br) = B
The terminal modification rate in the present invention is defined as follows.
Terminal modification rate = B / A × 100 (%)
The terminal modification rate in the present invention is calculated from the A value and B value obtained using LowCisBR having the same absolute molecular weight (number average molecular weight) as HighCisBR.
Note that the UV / RI value obtained by subtracting the value of the unmodified line shown in FIG. 1 is used as the true value, assuming that the terminal modification rate of the unmodified polymer reacted with isopropanol is 0%. The A and B values are shown in FIG.
The three straight lines shown in FIG. 1 can be used as a calibration curve. For example, if the absolute molecular weight Mn (number average) of HighCisBR is known, the terminal modification rate can be calculated.
As can be seen from FIG. 1, as the absolute molecular weight Mn (number average) increases, the terminal modification rate decreases and it becomes difficult to modify with a modifier.
Moreover, it is necessary to create a calibration curve each time the denaturant changes.

  Details of the analysis results of the conjugated diene polymer in each Example and Comparative Example are shown in Table 1-1 and Table 1-2.

＊１：トリスビストリメチルシリルアミドガドリニウム
＊２：ビス（２−フェニルインデニル）ガドリニウムビス（ジメチルシリルアミド）

＊１：トリスビストリメチルシリルアミドガドリニウム
＊２：ビス（２−フェニルインデニル）ガドリニウムビス（ジメチルシリルアミド）

* 1: Trisbistrimethylsilylamide gadolinium * 2: Bis (2-phenylindenyl) gadolinium bis (dimethylsilylamide)

* 1: Trisbistrimethylsilylamide gadolinium * 2: Bis (2-phenylindenyl) gadolinium bis (dimethylsilylamide)

  From the comparison between Examples 1-9 and Comparative Examples 1-2, the reaction system containing the conjugated diene polymer obtained by polymerizing the conjugated diene monomer was cooled, and the conjugated diene polymer in the cooled reaction system It was shown that a modified conjugated diene polymer having a high modification rate can be easily produced by modifying.

  According to the method for producing a modified conjugated diene polymer of the present invention, a modified conjugated diene polymer having a high modification rate can be easily produced. Furthermore, according to the modified conjugated diene polymer of the present invention, a modified conjugated diene polymer having a high modification rate can be provided. Furthermore, according to the rubber composition of the present invention, the effect of the modified conjugated diene polymer of the present invention can be obtained. Furthermore, according to the tire of the present invention, the effect of the modified conjugated diene polymer of the present invention can be obtained.

Claims (8)

A polymerization reaction step in which a conjugated diene monomer is polymerized in the presence of the polymerization catalyst composition to obtain a conjugated diene polymer;
A cooling step for cooling the reaction system after the polymerization reaction step;
A modification reaction step of modifying the conjugated diene polymer after the cooling step, and a method for producing a modified conjugated diene polymer.   The method for producing a modified conjugated diene polymer according to claim 1, wherein the reaction system is cooled to 50 ° C or lower in the cooling step. The polymerization catalyst composition has the following formula (I)
YR ¹ _a R ² _b R ³ _c (I)
(In the formula, Y is a metal element selected from the group consisting of elements of Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R ¹ and R ² are each of 1 to 10 is a hydrocarbon group or a hydrogen atom, R ³ is a hydrocarbon group having 1 to 10 carbon atoms, provided that R ¹ , R ² and R ³ may be the same or different from each other; Is a Group 1 metal element, a is 1 and b and c are 0, and when Y is a Group 2 or Group 12 metal element, a and b are 1 And when c is 0 and Y is a Group 13 metal element, a, b and c are 1.
The manufacturing method of the modified conjugated diene polymer of Claim 1 or 2 containing the organometallic compound represented by these. The method for producing a modified conjugated diene polymer according to claim 3, wherein in the formula (I), R ¹ , R ² and R ³ are not all the same.   The method for producing a modified conjugated diene polymer according to any one of claims 1 to 4, wherein the conjugated diene monomer is butadiene or isoprene.   A modified conjugated diene polymer produced by the method for producing a modified conjugated diene polymer according to any one of claims 1 to 5.   A rubber composition comprising the modified conjugated diene polymer according to claim 6.   A tire manufactured using the rubber composition according to claim 7.

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