JP2014058651A - Method for producing modified conjugated diene polymer and the modified conjugated diene polymer, and the modified conjugated diene polymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing modified conjugated diene polymer having a high cis content and a high ratio of modification by a wide range of modifiers, and a modified conjugated diene polymer produced by said method, and a modified conjugated diene polymer composition comprising said modified conjugated diene polymer.SOLUTION: A method for producing modified conjugated diene polymer includes: a polymerization step in which a conjugated diene polymer is obtained by polymerizing a conjugated diene monomer using a particular rare earth complex compound derived from any one selected from the group consisting of lanthanoid elements, Sc, and Y; and a modification step in which a modified conjugated diene polymer is obtained by reacting the conjugated diene polymer with a compound capable of reacting with the conjugated diene polymer.

Description

  The present invention relates to a method for producing a modified conjugated diene polymer, a modified conjugated diene polymer produced by the method, and a modified conjugated diene polymer composition containing the modified conjugated diene polymer.

  Conjugated diene polymers are used as raw rubber in various fields. For example, for tires, it is used in a tread because it is excellent in wear resistance and flexibility at low temperatures, and is also used in a carcass because it is excellent in low heat resistance and bending crack resistance.

  Among them, the rubber has high stereoregularity such as natural rubber having a cis 1,4 bond content (hereinafter also referred to as “cis content”) of almost 100% and polybutadiene having a cis 1,4 bond content of 98% or more. It is known that a conjugated diene polymer can obtain high tensile strength by crystallization during stretching (for example, see Non-Patent Document 1).

  These conjugated diene polymers having high stereoregularity are conventionally produced using a coordination polymerization catalyst. Various catalyst systems using Ti, Co, Ni, etc. are known as such coordination polymerization catalysts. Also, industrially, conjugated diene polymers having a high cis content are produced using these catalyst systems (see, for example, Non-Patent Document 2).

  In the latter half of the 1970s, a polymerization system using a rare earth catalyst such as a rare earth carboxylate has been proposed. In the polymerization system using the rare earth carboxylate catalyst, the cis content is usually about 94 to 97%, but the polymerization activity is higher than that of the conventional Co, Ni, Ti catalyst, and the polymerization temperature is 60 to 80 ° C. Polymerization is possible at a higher temperature as described above, and the molecular weight distribution is narrow. Thus, it has characteristics not found in conventional catalyst systems (see, for example, Patent Documents 1 and 2 and Non-Patent Document 3).

  Furthermore, for the purpose of improving the cis content, a polymerization system using a binuclear complex of a rare earth and an alkylaluminum has been proposed. This polymerization system exhibits a high cis selectivity with a cis content of 99% or more in the polymerization of isoprene. (For example, refer nonpatent literature 4).

  Furthermore, a polymerization system using a rare earth metallocene complex has been proposed. In this polymerization system, a polymer having a cis content of 96 to 100% is obtained (see, for example, Patent Documents 3, 4, 5, 6, and 7).

  In recent years, demands for reducing fuel consumption of automobiles are increasing in relation to social demands for energy saving. High cis-1,4 polybutadiene obtained by polymerization using a catalyst containing a rare earth element is generally a linear polymer with few branched structures, and therefore uses a conventional catalyst mainly composed of cobalt, nickel, and titanium. Compared with high cis-1,4 polybutadiene obtained by polymerization, the cis content is high, and it has characteristics such as excellent wear resistance, heat resistance, fatigue resistance and the like. For this reason, high cis-1,4 polybutadiene obtained by polymerization using a catalyst containing a rare earth element has begun to be used as one of the rubber components of low-fuel-consumption tire rubber compositions.

  On the other hand, as a method for obtaining a rubber composition for a tire with low fuel consumption, many technical developments have been made so far to improve the dispersibility of the filler used in the rubber composition. Among them, in particular, a method is used in which the polymerization active terminal of a diene polymer obtained by anionic polymerization using an organolithium compound is modified with a functional group that interacts with a filler.

  On the other hand, it is known that a living polymer is produced even in coordination polymerization using a catalyst containing a rare earth element compound, and the living active terminal of the obtained polymer is modified with a specific coupling agent or modifier. (For example, refer to Patent Documents 8 to 10).

  However, in a conventionally known catalyst containing a lanthanum series rare earth element compound, the terminal modification rate is at most several tens of percent, but recently, a technique for increasing the terminal modification rate to less than 68% has been reported (for example, , See Patent Document 11). In addition, an example in which a high modification rate is achieved while realizing a high degree of microstructure control has been reported. Furthermore, an example of achieving high performance by branching the polymer simultaneously with modification has been reported.

EP0007027 JP 58-067705 JP 2008-291096 A JP 2007-63240 A JP 2004-27103 A JP 2003-292513 A JP 2000-313710 A JP-A-5-51406 JP-A-5-59103 Japanese translation of PCT publication No. 2003-514078 JP-T-2004-513987

Rubb. Chem. Technol. 30, 1118 (1957) Principles of Corderation Polymerization 275 Neodymium Based Ziegler Catalysts Fundamental Chemistry 132 Angew Chem Int. Ed. 2004 43 2234

  However, in the conventional techniques including Patent Documents 8 to 11, the degree of branching and the modification rate of the modified conjugated diene polymer cannot be sufficiently increased, and there is room for improvement. Moreover, in the technique described in Patent Document 10, the modification rate is 75% or more, but the cis content is low. Patent Document 11 achieves a high denaturation rate while maintaining a high cis content, but only a high cis content and a high denaturation rate are achieved with some denaturing agents. Some of them have extremely low rates, and functional groups can be introduced only with a modifier having a limited structure, which is not technically complete. From the viewpoint of polymer design, it is preferable that a high modification rate can be achieved with any modifier, but the present situation is that no catalyst system capable of such a modification reaction has yet been found.

  In the prior art, there is also a problem in the method for measuring the modification rate. As a spectroscopic method, there is a method in which RI and UV are measured by gel permeation chromatography (GPC) and the modification ratio is obtained by the intensity ratio. In this case, only a denaturant having a UV absorption wavelength is accurate. The rate of denaturation cannot be measured. Moreover, since the functional group concentration in the polymer varies depending on the molecular weight, the low molecular side tends to be measured with a high modification rate, and the polymer side tends to be measured with a low modification rate. In addition, there is a method of quantifying a specific element in the denaturant, but in this case, the denaturant that is not denatured is also detected, so that an accurate denaturation rate cannot be obtained. In addition, there is a method of adsorbing using a GPC column, but there are problems such as dependence on molecular weight and the influence of the three-dimensional structure of the polymer as described above.

  The present invention has been made in view of the above problems, and has a high cis content and a method for producing a modified conjugated diene polymer having a wide range of modifiers and a high modification rate, and the method. It is an object of the present invention to provide a modified conjugated diene polymer and a modified conjugated diene polymer composition containing the modified conjugated diene polymer.

  As a result of intensive research to solve the above problems, the present inventors have conducted a high degree of modification rate with a wide range of modifiers while maintaining a high cis content when polymerized using a specific catalyst composition. As a result, the present invention has been completed. In addition, we have found that only a modified polymer can be efficiently separated by using a specific adsorbent, and as a result, we have found a method for measuring the modification rate to accurately determine the mass fraction of the modified polymer and the unmodified polymer. Furthermore, a modified conjugated diene-based polymer having a specific cis content and having a mass fraction of a certain value or more was found to be very useful as a tire composition, and the present invention was completed. .

（式（１）及び（２）中、Ｌｎは、ランタノイド元素、Ｓｃ、及びＹからなる群から選択されるいずれか１種を示し、Ｒ^１〜Ｒ^４は、同一でも異なってもよく、水素原子、炭素数１〜８の、アルキル基、アルキルシリル基、アルキルオキシ基、及びジアルキルアミド基、及び炭素数６−８のアリール基、からなる群から選択されるいずれか１種を示す。）
〔２〕
前記重合工程において、前記希土類系錯体化合物と、アルキルアルミニウム、アルキルアルミニウムオキシ化合物、及びボラン系化合物からなる群より選ばれる少なくとも１種の化合物と、の反応物とを用いる、前項〔１〕に記載の変性共役ジエン系重合体の製造方法。
〔３〕
前記共役ジエン系重合体と反応可能な化合物が、シリル基を有する、前項〔１〕又は〔２〕に記載の変性共役ジエン系重合体の製造方法。
〔４〕
前記共役ジエン系重合体と反応可能な化合物が、炭素−酸素２重結合を有する、前項〔１〕〜〔３〕のいずれか１項に記載の変性共役ジエン系重合体の製造方法。
〔５〕
前記共役ジエン系重合体と反応可能な化合物が、炭素−窒素２重結合を有する、前項〔１〕〜〔４〕のいずれか１項に記載の変性共役ジエン系重合体の製造方法。
〔６〕
前記共役ジエン系重合体と反応可能な化合物が、酸素を含む環状構造を有する、前項〔１〕〜〔５〕のいずれか１項に記載の変性共役ジエン系重合体の製造方法。
〔７〕
前記共役ジエン系重合体と反応可能な化合物が、アミノ基を有する、前項〔１〕〜〔６〕のいずれか１項に記載の変性共役ジエン系重合体の製造方法。
〔８〕
シスコンテンツ９８％以上であり、変性率が２０ｗｔ％以上である、変性共役ジエン系重合体。
〔９〕
シスコンテンツ９４％以上であり、変性率が４０ｗｔ％以上である、変性共役ジエン系重合体。
〔１０〕
前項〔１〕〜〔７〕のいずれか１項に記載の変性共役ジエン系重合体の製造方法により得られる変性共役ジエン系重合体と、
充填剤とを含む、変性共役ジエン系重合体組成物。 That is, the present invention is as follows.
[1]
A polymerization step of polymerizing a conjugated diene monomer using a rare earth complex compound represented by the following formula (1) and / or (2) to obtain a conjugated diene polymer;
A modification step of obtaining a modified conjugated diene polymer by reacting the conjugated diene polymer with a compound capable of reacting with the conjugated diene polymer.
A method for producing a modified conjugated diene polymer.

(In the formulas (1) and (2), Ln represents any one selected from the group consisting of lanthanoid elements, Sc, and Y, and R ^{1 to} R ⁴ may be the same or different, and hydrogen Any one selected from the group consisting of an atom, an alkyl group having 1 to 8 carbon atoms, an alkylsilyl group, an alkyloxy group, a dialkylamide group, and an aryl group having 6 to 8 carbon atoms is shown.)
[2]
In the polymerization step, the reaction product of the rare earth complex compound and at least one compound selected from the group consisting of an alkylaluminum, an alkylaluminumoxy compound, and a borane compound is used as described in the above item [1]. A process for producing a modified conjugated diene polymer.
[3]
The method for producing a modified conjugated diene polymer according to [1] or [2] above, wherein the compound capable of reacting with the conjugated diene polymer has a silyl group.
[4]
The method for producing a modified conjugated diene polymer according to any one of [1] to [3], wherein the compound capable of reacting with the conjugated diene polymer has a carbon-oxygen double bond.
[5]
The method for producing a modified conjugated diene polymer according to any one of [1] to [4], wherein the compound capable of reacting with the conjugated diene polymer has a carbon-nitrogen double bond.
[6]
The method for producing a modified conjugated diene polymer according to any one of [1] to [5], wherein the compound capable of reacting with the conjugated diene polymer has a cyclic structure containing oxygen.
[7]
The method for producing a modified conjugated diene polymer according to any one of [1] to [6], wherein the compound capable of reacting with the conjugated diene polymer has an amino group.
[8]
A modified conjugated diene polymer having a cis content of 98% or more and a modification rate of 20 wt% or more.
[9]
A modified conjugated diene polymer having a cis content of 94% or more and a modification rate of 40 wt% or more.
[10]
A modified conjugated diene polymer obtained by the method for producing a modified conjugated diene polymer according to any one of [1] to [7] above;
A modified conjugated diene polymer composition comprising a filler.

  According to the present invention, a method for producing a modified conjugated diene polymer having a high cis content and a high modification rate with a wide range of modifiers, a modified conjugated diene polymer produced by the method, and the method A modified conjugated diene polymer including a modified conjugated diene polymer is realized.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiment, and can be implemented with various modifications within the scope of the gist.

（式（１）及び（２）中、Ｌｎは、ランタノイド元素、Ｓｃ、及びＹからなる群から選択されるいずれか１種を示し、Ｒ^１〜Ｒ^４は、同一でも異なってもよく、水素原子、炭素数１〜８の、アルキル基、アルキルシリル基、アルキルオキシ基、及びジアルキルアミド基、及び炭素数６−８のアリール基、からなる群から選択されるいずれか１種を示す。） [Method for producing modified conjugated diene polymer]
The method for producing the modified conjugated diene polymer of the present embodiment is as follows:
A polymerization step of polymerizing a conjugated diene monomer using a rare earth complex compound represented by the following formula (1) and / or (2) to obtain a conjugated diene polymer;
A modification step of obtaining a modified conjugated diene polymer by reacting the conjugated diene polymer with a compound capable of reacting with the conjugated diene polymer.

(In the formulas (1) and (2), Ln represents any one selected from the group consisting of lanthanoid elements, Sc, and Y, and R ^{1 to} R ⁴ may be the same or different, and hydrogen Any one selected from the group consisting of an atom, an alkyl group having 1 to 8 carbon atoms, an alkylsilyl group, an alkyloxy group, a dialkylamide group, and an aryl group having 6 to 8 carbon atoms is shown.)

[Polymerization process]
The polymerization step in the present embodiment is a step of obtaining a conjugated diene polymer by polymerizing a conjugated diene monomer using the rare earth complex compound represented by the formula (1) and / or (2). is there.

(Conjugated diene monomer)
Although it does not specifically limit as a conjugated diene type monomer, Specifically, all of linear diene, cyclic diene, and the diene which has a substituent can be used. More specifically, 1,3-butadiene, 1,3-isoprene, 1,4-dimethyl-1,3-butadiene, 1,2-dimethyl-1,3-butadiene, 1,3-dimethyl-1, Examples include 3-butadiene, 1,2,3-trimethyl-1,3-butadiene, cyclohexadiene, 1-vinylcyclohexene, 1,3,5-hexatriene, and alloocimene.

（式（１）及び（２）中、Ｌｎは、ランタノイド元素、Ｓｃ、及びＹからなる群から選択されるいずれか１種を示し、Ｒ^１〜Ｒ^４は、同一でも異なってもよく、水素原子、炭素数１〜８の、アルキル基、アルキルシリル基、アルキルオキシ基、及びジアルキルアミド基、及び炭素数６−８のアリール基、からなる群から選択されるいずれか１種を示す。）

（式（３）中、Ｌｎはランタノイド元素、Ｓｃ、及びＹからなる群から選択されるいずれか１種を示し、Ｒ^１〜Ｒ^１２は同じでも異なってもよく、水素、炭素数１〜８の、アルキル基、アルキルシリル基、アルキルオキシ基、及びジアルキルアミド基、及び炭素数６−８のアリール基、からなる群から選択されるいずれか１種を示す。） (Rare earth complex compounds)
The rare earth-based complex compound is not particularly limited as long as it is a compound represented by the formula (1) and / or (2), and specific examples thereof include lanthanoid-aluminum cross-linked complexes. ) Is preferred. Here, as the structure of the lanthanoid-aluminum cross-linked complex in the present embodiment, the structure of the above formula (2) is confirmed from the X-ray structural analysis. However, in reality, the structure of the formula (2) is a structure at a cryogenic state or at a certain moment, and at room temperature, the alkyl group (and other functional groups) of the formula (2) has a considerably high speed. Cause an exchange reaction. In the above formula (2), R ¹ and R ³ are bonded to Ln and Al, but actually, R ¹ and R ³ are present at a certain moment, and R ² and R ⁴ are present at the next moment. At the next moment, arbitrary R repeats bonding and exchange, such as R ³ and R ⁴ , and takes the structure of the above formula (1). On the other hand, since the replacement is slow in an extremely low temperature state, the structure of the above formula (2) is adopted. Therefore, when the state at room temperature is confirmed by NMR or the like, usually, if the structure is the above formula (2), the peaks of R ¹ and R ³ , the peaks of R ² and R ⁴ and the two peaks are confirmed. As described above, since the exchange of substituents is fast, it appears as one peak in the middle of the two peaks. That is, it can also be expressed as if Al is attached to Al as in the structure of Formula (1), and (AlR ₄ ) is entirely attached to Ln as a functional group. On the other hand, since the exchange of R is slow in the cryogenic state, two peaks appear. Therefore, the structure of the above formula (1) represents the state of the complex at room temperature, and the structure of the above formula (2) represents the state of the complex at a very low temperature state or at a certain moment. That is, the complexes of the above formulas (1) and (2) are exactly the same, but from the NMR results, it is more appropriate to express as in formula (1), and from the results of X-ray structural analysis, the formulas It is more appropriate to express as (2).

(In the formulas (1) and (2), Ln represents any one selected from the group consisting of lanthanoid elements, Sc, and Y, and R ^{1 to} R ⁴ may be the same or different, and hydrogen Any one selected from the group consisting of an atom, an alkyl group having 1 to 8 carbon atoms, an alkylsilyl group, an alkyloxy group, a dialkylamide group, and an aryl group having 6 to 8 carbon atoms is shown.)

(In the formula (3), Ln represents any one selected from the group consisting of a lanthanoid element, Sc and Y, and R ^{1 to} R ¹² may be the same or different, and hydrogen, carbon number 1 to 8 Any one selected from the group consisting of an alkyl group, an alkylsilyl group, an alkyloxy group, a dialkylamide group, and an aryl group having 6 to 8 carbon atoms.)

  In the formulas (1) to (3), the lanthanoid element is not particularly limited, but preferably La, Ce, Pr, Nd, Sm, Eu, Gd, and Lu, and more preferably La, Ce, Nd, Gd is mentioned.

R ^{1 to} R ⁴ in the formulas (1) to (2) and R ^{1 to} R ¹² in the formula (3) may be the same or different, and each represents hydrogen, an alkyl group having 1 to 8 carbon atoms, or a carbon number. Any one selected from the group consisting of an alkylsilyl group having 1 to 8 carbon atoms, an alkyloxy group having 1 to 8 carbon atoms, a dialkylamide group having 1 to 8 carbon atoms, and an aryl group having 6 to 8 carbon atoms Indicates. Specific examples of the alkyl group having 1 to 8 carbon atoms represented by R ^{1 to} R ⁴ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, and an isopentyl group. , Cyclopentyl group, hexyl group, cyclohexyl group, octyl group, 2-ethylhexyl group and the like. Among these, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a cyclopentyl group, and a cyclohexyl group are preferable, and a methyl group, an ethyl group are more preferable. Group, propyl group, isopropyl group, butyl group, isobutyl group.

  Moreover, although it does not specifically limit as a C1-C8 alkylsilyl group, Specifically, a trimethylsilyl group, a dimethylsilyl group, a trimethoxysilyl group, a triethoxysilyl group, etc. are mentioned.

  Further, the alkyloxy group having 1 to 8 carbon atoms is not particularly limited, and specifically, methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, t-butoxy group, pentoxy group. , Isopentoxy group, cyclopentoxy group, hexoxy group, cyclohexoxy group, octoxy group, 2-ethylhexoxy group and the like. Among these, preferred are a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a t-butoxy group, a cyclopentoxy group, and a cyclohexoxy group, and more preferably A methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, and an isobutoxy group.

  Further, the dialkylamide group having 1 to 8 carbon atoms is not particularly limited, and specifically, dimethylamide group, diethylamide group, dipropylamide group, diisopropylamide group, dibutylamide group, diisobutylamide group, bis Examples thereof include a trimethylsilylamide group and a bisdimethylsilylamide group.

  Although it does not specifically limit as a C6-C8 aryl group, Specifically, a phenyl group, a methylphenyl group, etc. are mentioned.

  In the polymerization step of the present embodiment, it is preferable to use a reaction product of a rare earth complex compound and at least one compound selected from the group consisting of alkylaluminum compounds, alkylaluminumoxy compounds, and borane compounds.

(Alkyl aluminum compound)
The alkylaluminum compound is not particularly limited, and specifically, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-t-butylaluminum. , Tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, diethylaluminum hydride, di-n-propylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride, dihexylaluminum hydride, Diisohexyl aluminum hydride, dioctyl aluminum hydride, diisooctyl aluminum hydride, ethyl aluminum dihydride n- propyl aluminum dihydride, and include isobutyl aluminum dihydride and the like.

(Alkyl aluminum oxy compounds)
The alkylaluminum oxy compound is not particularly limited, and specific examples include methylaluminoxane, ethylaluminoxane, n-propylaluminoxane, n-butylaluminoxane, isobutylaluminoxane, t-butylaluminoxane, hexylaluminoxane, and isohexylaluminoxane. Can be mentioned.

  As a method for producing these aluminoxanes, any known technique may be used. For example, trialkylaluminum or dialkylaluminum monochloride is added to an organic solvent such as benzene, toluene, or xylene, and water, water vapor, It can be produced by adding water vapor-containing nitrogen gas or a salt having crystal water such as copper sulfate pentahydrate or aluminum sulfate 16-hydrate to cause a reaction. The alkylaluminum oxy compounds can be used alone or in combination of two or more.

(Borane compounds)
Although it does not specifically limit as a borane type compound, Specifically, a triphenyl borane, a tris pentafluoro phenyl borane, etc. are mentioned.

(Borate compounds)
Although it does not specifically limit as a borate type compound, Specifically, ammonium tetrakisphenyl borate, ammonium tetrakis pentafluorophenyl borate, a trityl tetrakis phenyl borate, a trityl tetrakis pentafluorophenyl borate etc. are mentioned.

(Metal halide compound or silyl halide compound)
In the polymerization step of the present embodiment, a rare earth complex compound and a reaction product of a halogenated metal compound or a halogenated silyl compound can be further used. The halogenated metal compound or halogenated silyl compound is not particularly limited. Specifically, dimethylaluminum chloride, methylaluminum dichloride, diethylaluminum chloride, ethylaluminum dichloride, ethylaluminum sesquichloride, silicon tetrachloride, trimethylchlorosilane, Examples include methyldichlorosilane, dimethyldichlorosilane, methyltrichlorosilane, titanium tetrachloride, tin tetrachloride, tin dichloride, phosphorus trichloride, benzoyl chloride, and t-butyl chloride.

  The reaction ratio between the rare earth complex compound and the alkylaluminum compound is preferably a molar ratio (rare earth complex compound: alkylaluminum compound) of 1: 0.1 to 1:50, and 1: 0.5 to 1: 10 is more preferred, and 1: 1 to 1: 8 is even more preferred.

  The reaction ratio between the rare earth complex compound and the alkylaluminum oxy compound is preferably a molar ratio (rare earth complex compound: alkylaluminum oxy compound) of 1: 0 to 1: 5000, and 1: 1 to 1: 1000. More preferably, it is 1: 5 to 1: 500.

  The reaction ratio between the rare earth complex compound and the borane compound is preferably 1: 1 to 1: 5 in terms of a molar ratio of rare earth element to borane element (rare earth element: borane element), and 1: 1 to 1: 3 is more preferable, and 1: 1 to 1: 2 is even more preferable.

  The reaction ratio between the rare earth complex compound and the metal halide compound or silyl halide compound is preferably a molar ratio of the rare earth element to the halogen element (rare earth element: halogen element) of 1: 0 to 1: 5, The ratio is more preferably 1: 1 to 1: 4.5, and further preferably 1: 1.5 to 1: 4.

(Method for preparing polymerization catalyst)
Examples of the preparation method of the polymerization catalyst include a method of mixing a rare earth complex compound and an alkylaluminum compound, an alkylaluminumoxy compound, a borane compound, a borate compound, a metal halide compound, or a halogenated silyl compound. In mixing, each compound component can be used after dissolving and diluting in a solvent or the like in advance. In this case, the solvent used for the polymerization is preferably a solvent that does not react with the polymerization catalyst and can produce an undesirable compound in the polymerization reaction. Such a solvent is not particularly limited. Specifically, hydrocarbon solvents such as pentane, n-hexane, heptane, octane, cyclopentane, and cyclohexane; benzene, toluene, xylene, cumene, and ethylbenzene, etc. Aromatic hydrocarbon solvents and the like. Moreover, the said solvent can be used individually by 1 type, or can also use 2 or more types together. In order to prepare the polymerization catalyst efficiently and with good reproducibility, it is preferably performed in a nitrogen atmosphere or an argon atmosphere. Argon filled with a commercially available argon cylinder may be used as it is, but it is preferable to remove oxygen and moisture in advance with a column or the like or use ultra-high purity nitrogen. Moreover, it is preferable that the appliance to be used is sufficiently dried in advance with a dryer or the like. Furthermore, it is preferable that the solvent and the monomer to be used are preliminarily removed from water, active hydrogen, a polar substance having a carbonyl group, etc. by a dehydrating agent or distillation purification.
As a mixing method,
1) A method of mixing only polymerization catalyst components in advance,
2) A method of mixing a polymerization catalyst component in the presence of a small amount of monomers to be polymerized,
3) A method of mixing catalyst components in the presence of a coordinating solvent or compound other than the monomer,
4) A method in which a catalyst component is mixed in the presence of a small amount of monomer to be polymerized and a coordinating solvent or compound other than the monomer, and 5) a reaction in which a polymerization catalyst component is introduced into a reactor charged with the monomer in advance. The method etc. which mix | blend in a container are mentioned. Hereinafter, each method will be described in detail.

1) Method of previously mixing only the polymerization catalyst component In this method, the catalyst component can be mixed in the presence of a solvent. The rare earth complex compound can be used as it is, but it is preferable to dissolve it in a solvent in advance. As the order of blending, the following order (i) and order (ii) are possible.

Sequence (i): A method in which an alkylaluminum oxy compound, a borane compound, or a borate compound is mixed with a rare earth complex compound, and then an alkylaluminum compound is added and finally a metal halide compound is added.

Sequence (ii): A method in which an alkylaluminum compound is mixed with a rare earth complex compound, an alkylaluminumoxy compound, a borane compound, or a borate compound is added, and finally a metal halide compound is added.

  In this case, preparation time should just have time which can mix and react each catalyst component. For example, the reaction time can be arbitrarily changed between about 0.5 to 120 minutes. If the reaction time is 0.5 minutes or longer, the reaction tends to proceed sufficiently. Moreover, since it is not necessary to lengthen reaction time more than necessary, it is sufficient to make it react for about 120 minutes. The temperature at the time of preparation can be set to a range of about −10 ° C. to 60 ° C. Moreover, the catalyst composition after the reaction can be stored for a long period of time under conditions in which temperature, moisture, oxygen and the like are properly controlled.

2) Method of mixing a polymerization catalyst component in the presence of a small amount of monomer to be polymerized In this method, the catalytic component can be mixed in the presence of a solvent and a monomer used for polymerization. The ratio of the rare earth complex compound to the monomer is preferably about 1: 1 to 1: 2000 in terms of molar ratio (rare earth complex compound: monomer). As the mixing order, the following orders (i) and (ii) are possible.

Sequence (i): A predetermined amount of monomer and solvent are mixed in advance, and an alkylaluminum oxy compound, borane compound, or borate compound is added to the rare earth complex compound, and then an alkylaluminum compound is added. A method of adding a metal halide compound.

Sequence (ii): A predetermined amount of monomer and a solvent are mixed in advance, and then an alkylaluminum compound is added to the rare earth complex compound, and then an alkylaluminumoxy compound, borane compound, or borate compound is added, and finally A method of adding a metal halide compound to the surface.

  In this case, preparation time should just have the time which each catalyst component mixes and can react, and the time which a catalyst composition and a monomer can react. For example, the reaction time can be arbitrarily changed between about 0.5 to 120 minutes. If the reaction time is 0.5 minutes or longer, the reaction tends to proceed sufficiently. Further, since it is not necessary to make the reaction time longer than necessary, it is sufficient to react for about 120 minutes at the longest. The temperature at the time of preparation can be set to a range of about −10 ° C. to 60 ° C. Moreover, the catalyst composition after the reaction can be stored for a long period of time under conditions in which temperature, moisture, oxygen and the like are properly controlled.

3) Method of mixing catalyst components in the presence of a coordinating solvent or compound other than the monomer In this method, the catalytic component is mixed in the presence of the coordinating solvent or compound other than the solvent and the monomer. Can do. The ratio of the rare earth complex compound to the monomer is preferably about 1: 1 to 1: 2000 in terms of molar ratio (rare earth complex compound: monomer). In this case, the coordinating solvent other than the monomer is not particularly limited, and specific examples include a compound having an aromatic ring, a compound having an unshared electron pair, an aprotic solvent, and the like. Toluene, xylene, ethylbenzene, mesitylene, cumene, butylbenzenes, diethyl ether, tetrahydrofuran, pyridine and the like. Examples of the coordinating compound other than the monomer include a compound having an unshared electron pair, a compound having a carbon-carbon double bond, and the like. Examples of such compounds include tertiary amines, alkyl phosphines, aryl phosphines, phosphites, cyclic olefins, substituted dienes, and cyclic dienes.

(I): A predetermined amount of a coordinating compound and a solvent are mixed in advance, and an alkylaluminum oxy compound, borane compound, or borate compound is added to the rare earth complex compound, and then an alkylaluminum compound is added. A method of adding a metal halide compound to the surface.

(Ii): A predetermined amount of a coordinating compound and a solvent are mixed in advance, and an alkylaluminum compound is added to the rare earth complex compound, and then an alkylaluminumoxy compound, a borane compound, and a borate compound are added. A method of adding a metal halide compound.

  In this case, preparation time should just have time which can mix and react each catalyst component. For example, the reaction time can be arbitrarily changed between about 0.5 to 120 minutes. If the reaction time is 0.5 minutes or longer, the reaction tends to proceed sufficiently. Moreover, since it is not necessary to lengthen reaction time more than necessary, it is sufficient to make it react for about 120 minutes. The temperature at the time of preparation can be set to a range of about −10 ° C. to 60 ° C. Moreover, the catalyst composition after the reaction can be stored for a long period of time under conditions in which temperature, moisture, oxygen and the like are properly controlled.

4) A method of mixing a catalyst component in the presence of a small amount of monomer to be polymerized and a coordinating solvent or compound other than the monomer In this method, a small amount of monomer to be polymerized and a coordinating solvent or compound other than the monomer The catalyst components can be mixed in the presence of. As the coordinating solvent or compound other than the monomer, those similar to those exemplified in the above method 3) can be used. Examples of the monomer include the conjugated diene monomer. The amount of the monomer is small and is not particularly limited, but the ratio of the rare earth complex compound to the monomer is preferably about 1: 1 to 1: 2000 in terms of molar ratio (rare earth complex compound: monomer).

5) A method of introducing a polymerization catalyst component into a reactor charged with monomers in advance and preparing it in the reactor In this method, the polymerization catalyst component is introduced into a reactor charged with monomers and polymerized in the reactor. A catalyst can be formulated. The order of introduction of the polymerization catalyst component is not particularly limited, and examples of the monomer include the conjugated diene monomers.

  The polymerization reaction using the catalyst composition can be performed under any conditions in the presence or absence of a solvent. When the polymerization is carried out in the presence of a solvent, it is preferable to use a solvent that does not react with the catalyst composition described above to produce an unfavorable compound in the polymerization reaction. Examples of such a solvent include, but are not limited to, butane, pentane, n-hexane, heptane, octane, cyclopentane, cyclohexane, 1-butene, 2-butene, and 1,2-butadiene. Hydrocarbon compounds: aromatic hydrocarbon compounds such as benzene, toluene, xylene, cumene, and ethylbenzene. Moreover, the said solvent can be used individually by 1 type, or can also use 2 or more types together.

  Since the catalyst composition prepared as described above reacts with water and polar substances, it is better to remove the water, polar substances, stabilizers, etc. in advance by using a dehydrating agent, distillation, etc. preferable. Water and polar substances can be removed by the following methods 1) to 3).

Method 1) Method of removing moisture through a column containing a dehydrating agent such as alumina or molecular sieves It is preferable that the column is dried in advance and the dehydrating agent is activated by removing moisture under high temperature vacuum. As the solvent for dehydration, it is more preferable to use a commercially available dehydration solvent.

Method 2) Method of distillation purification in the presence of a dehydrating agent A method of distillation after refluxing in the presence of a dehydrating agent such as calcium hydride, sodium, sodium benzophenone ketyl and the like.

Method 3) A method of removing moisture by adding a compound such as alkylaluminum, alkyllithium, or alkylmagnesium to a solvent to be used in advance and reacting with moisture, a polar substance or the like. This method is the simplest when the reactants do not affect the polymerization. As an additive, alkylaluminum is preferable. Further, the method 3) may be used in combination with the above methods 1) and 2).

  Although the polymerization temperature in a polymerization reaction is not specifically limited, -50-100 degreeC is preferable, -10-80 degreeC is more preferable, 0-70 degreeC is further more preferable. The polymerization time is not particularly limited, but is preferably about 1 minute to 6 hours, and more preferably about 5 minutes to 5 hours. However, these reaction conditions can be appropriately selected according to the type of the catalyst.

  The polymerization reaction in the present embodiment may be performed by either a batch or continuous polymerization method. Examples of the reactor used for the polymerization include a vessel type reactor and a tube type reactor. During the polymerization, the reactor may be heated and cooled in order to keep the reactor temperature at a predetermined temperature. As a heating method, a jacket, an internal coil, an external heat exchanger, or the like can be used, and heating can be performed with steam or a heat medium according to the purpose. Similarly, when cooling, a jacket, an internal coil, an external heat exchanger, a reflux device, or the like can be used. In cooling, cooling can be performed using sensible heat, latent heat, or the like of water, a refrigerant, or a solvent. Cooling may be performed by combining some of these methods.

  After the polymerization reaction reaches a predetermined polymerization rate, a known polymerization terminator is added to the polymerization reaction system to stop the reaction, and then the produced polymer can be separated from the polymerization reaction system by a usual method. .

  Although it does not specifically limit as a polymerization terminator, Specifically, it has compounds, such as water, alcohol, phenol, and active hydrogen, such as carboxylic acid; It has carbonyl groups, such as ketone, aldehyde, carboxylic acid, ester, and carbamate. Compounds; compounds having primary and secondary amino groups; compounds having epoxy groups and glycidyl groups; compounds having cyano groups.

[Modification step]
The modification step is a step of obtaining a modified conjugated diene polymer by reacting a conjugated diene polymer with a compound capable of reacting with the conjugated diene polymer (hereinafter also referred to as “modifier”).

  In the modification step, a compound having a functional group capable of reacting with the conjugated diene polymer is added to the reaction system after the polymerization or during the polymerization, thereby introducing the functional group into the conjugated diene polymer to obtain a desired modified diene. A polymer can be obtained. Specifically, there are the following methods 1) and 2).

Method 1) A method of obtaining a modified conjugated diene polymer by adding a modifier to the reaction system after the polymerization of the conjugated diene polymer and reacting for a predetermined time.

Method 2) While the conjugated diene polymer is being polymerized, while the modifier is gradually added to the reaction system, the polymerization and the modification reaction are allowed to proceed simultaneously, and after the polymerization is completed, the polymer is further reacted with the modifier for a predetermined time, A method for obtaining a modified conjugated diene polymer.

  As a method for introducing the denaturant into the reactor, in the case of the above method 1), either a method of introducing a predetermined amount of the denaturant with a pump or a method of pumping into the reactor using nitrogen or the like may be used. Further, the modifying agent may be divided and introduced in several times. Furthermore, the modifier may be introduced after diluted with a solvent. The solvent for diluting the modifier is not particularly limited as long as it is a solvent that can be used for polymerization. However, since a trace amount of impurities may inhibit the modification reaction, a solvent that removes impurities to the same level as the polymerization solvent. Is preferred.

  In the case of the above method 2), a method in which the denaturant is continuously introduced by a pump is generally used, but the denaturant is divided into several times and introduced into the reactor by pressure using nitrogen or the like. May be. The introduction can be started immediately after the start of polymerization mosquitoes and immediately before the end of polymerization. At the end of the introduction, it is possible from immediately after the start of polymerization to 30 minutes after the end of polymerization. Moreover, it is preferable to remove impurities such as moisture if the denaturing agent used in the denaturing reaction is possible.

  The amount of the modifier to be implanted is preferably in an amount ranging from an equimolar amount to the rare earth metal used for the polymerization to 3 times the total of the rare earth, alkylaluminum, and borate used for the polymerization. By making the amount of the rare earth metal equal to or greater than the equimolar amount, a sufficient amount of the modified conjugated diene polymer can be obtained. In addition, it is possible to obtain a sufficient amount of modified conjugated diene polymer as long as it is less than 3 times the total amount of rare earth, alkylaluminum, and borate used in the polymerization, and a large amount of unreacted modifier is polymer. There is a tendency for the deterioration of physical properties due to remaining in the inside to be suppressed.

  The reaction time with the modifying agent after adding the modifying agent is such that the reaction with the modifying agent proceeds sufficiently because the reaction time is 0.5 hours or longer. Moreover, it exists in the tendency for generation | occurrence | production of an unfavorable by-product to be suppressed because reaction time is 12 hours or less. Therefore, the reaction time is preferably 0.5 to 12 hours, more preferably 0.5 to 6 hours, and further preferably 0.5 to 3 hours.

  A preferable reaction temperature in the denaturation reaction is that the reaction with the denaturant tends to proceed sufficiently when the reaction time is 10 ° C. or more. Moreover, when reaction temperature is 90 degrees C or less, it exists in the tendency for generation | occurrence | production of an unfavorable by-product, and there exists a tendency for a modification | denaturation reaction rate to improve. Therefore, the reaction time is preferably 10 ° C to 90 ° C, more preferably 20 ° C to 80 ° C, and further preferably 30 ° C to 80 ° C.

(Compound capable of reacting with conjugated diene polymer)
The compound capable of reacting with the conjugated diene polymer is not particularly limited, and specifically, a compound having a silyl group such as a mercapto group-containing alkoxysilane compound; a ketone compound, an aldehyde compound, a carboxylic acid compound, an ester compound, Compounds having carbon-oxygen double bonds (carbonyl groups) such as acid anhydrides; Compounds having primary and secondary imide groups; Compounds having a cyclic structure containing oxygen such as epoxy groups and glycidyl groups; Examples thereof include compounds having an amino group such as alkoxysilane compounds; compounds having a carbon-nitrogen double bond such as imino group-containing alkoxysilane compounds.

  Although it does not specifically limit as a ketone compound, Specifically, 2-propanone, 2-butanone, 2-pentanone, 2-hexanone, 2-heptanone, 2-octanone, 3-pentanone, 2,4-pentanedione, Examples include 3-hexanone, 2,5-hexanedione, cyclopropanone, cyclobutanone, cyclopentanone, cyclohexanone, acetophenone, and benzophenone.

  The aldehyde compound is not particularly limited, and specific examples include formaldehyde, ethanal, propanal, butanal, pentanal, benzaldehyde, and acrylic aldehyde.

  The carboxylic acid compound is not particularly limited, and specifically, acetic acid, stearic acid, adipic acid, maleic acid, benzoic acid, acrylic acid, methacrylic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, Examples include pyromellitic acid, merit acid, polymethacrylic acid ester compound, and polyacrylic acid compound.

  The ester compound is not particularly limited, and specifically, ethyl acetate, ethyl stearate, diethyl adipate, diethyl maleate, methyl benzoate, ethyl acrylate, ethyl methacrylate, diethyl phthalate, dimethyl terephthalate , Tributyl trimellitic acid, tetraoctyl pyromellitic acid, hexaethyl meritate, phenyl acetate, polymethyl methacrylate, polyethyl acrylate, polyisobutyl acrylate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dihexyl carbonate, and diphenyl carbonate .

  The acid anhydride is not particularly limited, and specifically, acetic anhydride, propionic anhydride, isobutyric anhydride, isovaleric anhydride, heptanoic anhydride, benzoic anhydride, cinnamic anhydride, succinic anhydride, anhydrous Examples thereof include methyl succinic acid, maleic anhydride, glutaric anhydride, citraconic anhydride, phthalic anhydride, and a styrene-maleic anhydride copolymer.

  Although it does not specifically limit as a compound which has cyclic structures containing oxygen, such as an epoxy group and a glycidyl group, Specifically, N, N- diglycidyl aniline, N, N-diglycidyl-o-toluidine, N, N- Diglycidyl (-4-glycidyloxy) aniline, N, N-diglycidyl (-2-glycidyloxy) aniline, N, N, N ′, N′-tetraglycidylaminodiphenylmethane, trisepoxypropyl isocyanurate, N-glycidyl-di Butylamine, N-glycidylpyrrolidine, N-glycidylpiperidine, N-glycidylhexamethyleneimine, N-glycidylmorpholine, N, N'-diglycidylpiperazine, N, N'-diglycidylhomopiperazine, N-glycidyl-N'- Methylpiperazine, N-glycidyl-N'-ben Rupiperajin, and-N-2-diglycidyl-aminoethyl and methyl pyrrolidine.

  The amino group-containing alkoxysilane compound is not particularly limited. Specifically, 3-dimethylaminopropyl (triethoxy) silane, 3-dimethylaminopropyl (trimethoxy) silane, 3-diethylaminopropyl (triethoxy) silane, 3- Diethylaminopropyl (trimethoxy) silane, 2-dimethylaminoethyl (triethoxy) silane, 2-dimethylaminoethyl (trimethoxy) silane, 3-dimethylaminopropyl (diethoxy) methylsilane, 3-dibutylaminopropyl (triethoxy) silane, 3-amino Propyltrimethoxysilane, 3-aminopropyltriethoxysilane, aminophenyltrimethoxysilane, aminophenyltriethoxysilane, 3- (N-methylamino) propyltrimethoxysilane Emissions, and 3- (N- methylamino) can be exemplified propyl triethoxysilane.

  Although it does not specifically limit as a compound which has a silyl group, and an imino group containing alkoxysilane compound, Specifically, 3- (1-hexamethyleneimino) propyl (triethoxy) silane, (1-hexamethyleneimino) methyl (triethoxy). ) Silane, 2- (1-hexamethyleneimino) ethyl (triethoxy) silane, 3- (1-pyrrolidinyl) propyl (triethoxy) silane, 3- (1-heptamethyleneimino) propyl (triethoxy) silane, 3- (1 -Dodecamethyleneimino) propyl (triethoxy) silane, 3- (1-hexamethyleneimino) propyl (diethoxy) methylsilane, 3- (1-hexamethyleneimino) propyl (diethoxy) ethylsilane, N- (1,3-dimethylbutyrate) Redene) -3- (triethoxysilyl) -1-propanamine, N- (1-methylethylidene) -3- (triethoxysilyl) -1-propanamine, N-ethylidene-3- (triethoxysilyl) -1-propanamine, N- (1- Methylpropylidene) -3- (triethoxysilyl) -1-propanamine, N- (4-N, N-dimethylaminobenzylidene) -3- (triethoxysilyl) -1-propanamine, N- (cyclohexylene) Den) -3- (triethoxysilyl) -1-propanamine and their corresponding triethoxysilyl compounds, trimethoxysilyl compounds, methyldiethoxysilyl compounds, ethyldiethoxysilyl compounds, methyldimethoxysilyl compounds, or Ethyldimethoxysilyl compound, 1- [3- (triethoxysilyl) propyl] -4,5 Dihydroimidazole, 1- [3- (trimethoxysilyl) propyl] -4,5-dihydroimidazole, 3- [10- (triethoxysilyl) decyl] -4-oxazoline, 3- (1-hexamethyleneimino) propyl (Triethoxy) silane, (1-hexamethyleneimino) methyl (trimethoxy) silane, N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole, N- (3-isopropoxysilylpropyl) -4,5 -Dihydroimidazole, N- (3-methyldiethoxysilylpropyl) -4,5-dihydroimidazole and the like can be mentioned.

  The mercapto group-containing alkoxysilane compound is not particularly limited, and specific examples include 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 2-mercaptoethyltrimethoxysilane. , 3-mercaptopropyl (diethoxy) methylsilane, 3-mercaptopropyl (monoethoxy) dimethylsilane, mercaptophenyltrimethoxysilane, mercaptophenyltriethoxysilane, and the like.

  As the compound capable of reacting with these conjugated diene polymers, one kind may be used alone, or two or more kinds may be used in combination.

[Calculation method of modification rate of modified conjugated diene polymer]
The modified polymer and the non-modified polymer are separated using silica or an ion exchange resin, and the modification rate (hereinafter, also referred to as “mass fraction”) of the modified conjugated diene polymer can be calculated. This will be described below.

Method 1) A glass column or the like is filled with silica or an ion exchange resin, and a polymer solution in which a polymer containing a fixed mass of a modified conjugated diene polymer is dissolved is treated with the glass column. Thereafter, the polymer solution is dried under reduced pressure, and then the mass of the polymer is measured. At this time, the mass fraction (C) of the modified conjugated diene polymer can be calculated by the following method using the polymer adsorbed on the silica or ion exchange resin as the modified polymer.
C = [(A−B) / A] × 100
A: Mass of polymer dissolved in solvent B: Mass of polymer after column treatment C: Mass% of modified polymer

Method 2) A predetermined amount of silica or ion exchange resin is added to a polymer solution in which a polymer containing a fixed mass of a modified conjugated diene polymer is dissolved. After stirring for a predetermined time, the silica or ion exchange resin is separated by filtration, Wash the ion exchange resin. Thereafter, the cleaning liquid and the polymer solution are mixed and dried under reduced pressure, and then the mass of the polymer is measured. At this time, the mass fraction of the modified conjugated diene polymer can be calculated in the same manner as described above using the polymer adsorbed on the silica or ion exchange resin as the modified conjugated diene polymer.

Method 3) A polymer solution in which silica or an ion exchange resin is packed in a glass column or the like, and a polymer containing a fixed mass of a modified conjugated diene polymer and a reference polymer (for example, polystyrene) are dissolved in a solvent, After treatment with a column, the polymer solution is dried under reduced pressure, and then NMR is measured before and after the treatment. At this time, the mass fraction of the modified conjugated diene polymer can be calculated by the following method using the polymer adsorbed on the silica or ion exchange resin as the modified conjugated diene polymer.

(Oil Exhibition)
The modified conjugated diene polymer of the present embodiment may be made into an oil-extended polymer by adding process oil as necessary before the solvent removal step. The process oil is not particularly limited, but from the viewpoint of compatibility, aroma oil, naphthene oil, paraffin oil, aroma substitute oil having a polycyclic aromatic component of 3% by mass or less by IP346 method, and the like are preferable. Among these, it is preferable to use an aroma substitute oil having a polycyclic aromatic component of 3% by mass or less from the viewpoint of environmental safety, prevention of oil bleed, and wet grip characteristics. Aroma substitute oils include, for example, Treated Distilled Aromatic Extract (TDAE), Mildly Medium Extracted, etc. or Special Residual Aromatic Extract (SRAE). The amount of these extender oils to be used is not particularly limited, and is usually 10 to 60 parts by mass and preferably 20 to 37.5 parts by mass with respect to 100 parts by mass of the modified conjugated diene polymer.

(Finishing)
The modified conjugated diene polymer of this embodiment is added by a polymerization terminator and a stabilizer, if necessary, to the reaction system, and known desolvation and drying operations used in the production of the conjugated diene polymer, for example, by steam stripping. Desolvation, compressed water squeezing machine such as screw extruder squeezing dehydrator, expander dehydrator, hot air dryer, etc., concentrating in a flushing tank, and then devolatilizing with a vent extruder etc., directly with a drum dryer, etc. The polymer can be recovered by a method such as devolatilization. The polymerization terminator can be selected from water or a protic polar organic compound. Examples of the latter include various alcohols, phenols, and carboxylic acid compounds. The stabilizer can be selected from known conjugated diene polymer stabilizers and antioxidants. Particularly preferred examples of these include 2,6-di-tert-butyl-4-methylphenol, n-octadecyl-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate, 2 , 4-bis (n-octylthiomethyl) -6-methylphenol, N, N′-dialkyldiphenylamine, N-alkyldiphenylamine and the like. The resulting polymer is usually formed into a veil.

[Modified Conjugated Diene Polymer]
The modified conjugated diene polymer thus produced may contain a modified polymer and an unmodified polymer. According to the above production method, a modified conjugated diene polymer having a cis content of 98% or more and a modification rate of 20 wt% or more can be produced. A modified conjugated diene polymer having a cis content of 94% or more and a modification rate of 40 wt% or more can also be produced. Such a modified conjugated diene polymer can be a good rubber material for tires because the strength and dispersibility of the filler can be balanced.

[Modified Conjugated Diene Polymer Composition]
The modified conjugated diene polymer of this embodiment can be processed by a method usually used in the rubber industry and used as a rubber product. In this case, a modified conjugated diene polymer composition containing the modified conjugated diene polymer obtained in this embodiment and a filler is preferable. In addition to the filler, if necessary, it can be blended with other rubber materials and processed by adding a silane coupling agent, a rubber softener, a vulcanizing agent, a vulcanizing aid, and other additives. In blending, various mechanical mixers such as a Banbury mixer and a roll mill are used, and the modified conjugated diene polymer of this embodiment has a small torque during blending, and the dispersion of the filler even when the kneading time is short. Has the advantage of being good. Further, the tack of the blended fabric is excellent and suitable for processing rubber products.

(Other rubber)
Other rubber materials that can be blended are not particularly limited, and specific examples include natural rubber and synthetic rubber. Examples of the synthetic rubber include low cis-1,4 polybutadiene, VCR (vinyl cis butadiene rubber), SBR (styrene butadiene rubber), isoprene rubber, butyl rubber, EPDM (ethylene propylene diene rubber), and the like.

  The amount of other rubber materials that can be blended is not particularly limited, but is preferably 0 to 900 parts by mass with respect to 100 parts by mass of the modified conjugated diene polymer, depending on the required performance of the elastomer to be obtained. More preferably, it is -400 mass parts, and it is still more preferable that it is 50-300 mass parts.

(filler)
The filler is not particularly limited, and an organic or inorganic filler is used. Although it does not specifically limit as an organic filler, Specifically, carbon black, a synthetic resin type reinforcing particle, etc. are mentioned. The inorganic filler is not particularly limited, and specifically, precipitated silica, fumed silica, alumina, aluminum hydroxide, magnesium hydroxide, clay, talc, mica, diatomaceous earth, wollastonite, montmorillonite, zeolite, Examples thereof include inorganic fibrous materials such as glass fibers. Among these, carbon black and precipitated silica are preferably used from the viewpoint of reinforcing properties. As carbon black, various materials used in rubber compositions are usually used, and furnace black is particularly preferable. For example, SAF, ISAF, ISAF-HS, ISAF-LS, IISAF-HS, HAF, HAF-HS HAF-LS, FEF and the like. The precipitated silica, the nitrogen adsorption specific surface area (BET method) those 50 to 400 m ² / g by weight, more preferably from 100 to 250 m ² / g. The pH of the precipitated silica is generally 5.5 to 7, preferably about 5.5 to about 6.8. These reinforcing agents can be arbitrarily selected according to the required performance. Moreover, it can mix and use as needed.

  The addition amount of the filler is not particularly limited, but is preferably 5 to 200 parts by mass with respect to 100 parts by mass of the modified conjugated diene polymer from the viewpoint of processability and the performance of the obtained elastomer. More preferably, it is part by mass. Moreover, it is preferable that it is 5-150 mass parts with respect to 100 mass parts of raw rubber containing the conjugated diene polymer of this embodiment, and it is further more preferable that it is 10-100 mass parts.

(Silane coupling agent)
The silane coupling agent is a compound having a function to close the interaction between the rubber component and the inorganic filler described above, and having an affinity or binding group for each of the rubber component and the inorganic filler. . As the silane coupling agent, a compound having a sulfur bond part, an alkoxysilyl group, and a silanol group part in one molecule is generally used. The silane coupling agent that can be used is not particularly limited. For example, bis- [3- (triethoxysilyl) -propyl] -tetrasulfide, bis- [3- (triethoxysilyl) -propyl] -disulfide, bis- [2- (Triethoxysilyl) -ethyl] -tetrasulfide and the like. Although the addition amount of a silane coupling agent is not specifically limited, From an effect and economical viewpoint, it is preferable that it is 0.1-10 mass parts with respect to 100 mass parts of inorganic fillers, and 0.5-5 masses Part.

(Rubber softener)
Although it does not specifically limit as a softener for rubber | gum, Specifically, a mineral oil or a liquid or low molecular weight synthetic | combination or vegetable softener is used suitably. The amount of rubber softener added is not particularly limited, but from the viewpoints of compatibility and environmental safety, aroma oil, naphthenic oil, paraffin oil, and aroma substitute with 3% by mass or less of polycyclic aromatic components by IP346 method An oil or the like is preferable.

(Vulcanizing agent, etc.)
Although it does not specifically limit as a vulcanizing agent, Specifically, a radical initiator, sulfur, a sulfur compound, a vulcanization adjuvant, a vulcanization accelerator, etc. are used. Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur. Examples of the sulfur compound include sulfur monochloride, sulfur dichloride, and organic polysulfide. As the vulcanization aid, zinc white, stearic acid or the like is used. As the vulcanization accelerator, various known vulcanization accelerators are used, and guanidine compounds, thiourea compounds, thiazole compounds, thiuram compounds, sulfenamide compounds, and the like are used.

  As other additives, anti-aging agents, waxes, conductive agents, colorants and the like are used. Although it does not specifically limit as an anti-aging agent, Specifically, a p-phenylenediamine type compound, a naphthylamine type compound, a diphenylamine type compound, a quinoline type compound, a phenol type compound, etc. are mentioned.

  The wax is not particularly limited, and specific examples include polyethylene wax and paraffin wax.

  Although it does not specifically limit as a electrically conductive agent, Specifically, carbon black, graphite, carbon fiber, a carbon nanotube, a metal powder, a fiber, etc. are mentioned.

  Although it does not specifically limit as a coloring agent, Specifically, carbon black, a phthalocyanine, a quinacridone, an indoline, an azo pigment, a bengara, etc. are mentioned.

(Manufacture of vulcanized rubber products)
The modified conjugated diene polymer of this embodiment is used for the production of various rubber products by blending and vulcanizing additives. In particular, it is optimally used as a raw material rubber for tires, and is preferably used because it has excellent wear resistance and flexibility at low temperatures in treads, and low heat generation and flex crack resistance in carcass. It is also used for manufacturing various industrial products and shoe soles.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

All solvents, monomers, nitrogen, and instruments used in the examples were purified and used in advance. Each purification method will be described below.
Nitrogen: Nidec Seiko's dehydration column (zeolite) and deoxygenation column (reduced metal) were used.
Solvent: The solvent for the synthesis of the rare earth complex compound was distilled after refluxing for 24 hours or more in the presence of benzophenone ketyl, and was used after confirming that the water content was less than 1 ppm with a Karl Fischer moisture meter. Moreover, unless otherwise indicated, the solvent for catalyst preparation and the solvent for polymerization were used after confirming that the water content was less than 1 ppm through a previously activated alumina column.
Monomer: Purified and used in the same manner as the polymerization solvent.
Instruments: Before use, after drying for 24 hours with a dryer at 100 ° C.

(1) Polymerization conversion rate:
A polymer solution is collected from a reactor in a pressure-resistant bottle in which a predetermined amount of n-propylbenzene and toluene are mixed, and the peak ratio of n-propylbenzene and butadiene is obtained by using n-propylbenzene as a standard substance in gas chromatography. I asked for it.

(2) Molecular weight and molecular weight distribution:
The polymer solution was collected from the reactor, and the polymer solution was washed three times with a 1N aqueous hydrochloric acid solution in a separatory funnel and then reprecipitated in methanol. After adding a stabilizer and drying at 50 ° C. for 3 hours, using a tetrahydrofuran solution to which α-methylstyrene dimer is added as an internal standard, the average molecular weight (Mw), the number average molecular weight (Mn), the molecular weight as the polystyrene equivalent molecular weight by GPC Distribution (Mw / Mn) was determined.

(3) Microstructure:
The polymer solution was collected from the reactor, and the polymer solution was washed three times with a 1N hydrochloric acid aqueous solution in a separatory funnel and then reprecipitated in methanol. After adding a stabilizer and drying at 50 ° C. for 3 hours, the obtained polymer was dissolved in deuterated chloroform, and ¹ H-NMR and ¹³ C-NMR were measured. The ratio of 1,4-bond to 1,2-bond is such that the peak area in the vicinity of 4.94 to 5.03 ppm (derived from 1,2 bond) of ¹ H-NMR and 5.30 to 5.50 ppm (1 , Derived from 4 bonds). In addition, the ratio of 1,4 cis bond to 1,4 trans bond in 1,4-bond is the peak area near 25.5 ppm (cis bond) and 32.8 ppm (trans bond) in ¹³ C-NMR. ) It was obtained from the area ratio with the area of nearby peaks.

(4) Denaturation rate:
Silica or ion exchange resin was packed in a glass column, and a polymer solution containing a fixed mass of a modified conjugated diene polymer was passed through the column. Thereafter, the polymer solution was dried under reduced pressure, and the mass of the polymer was measured. At this time, the modification rate (C) of the modified conjugated diene polymer was calculated by the following method using the polymer adsorbed on the silica or the ion exchange resin as the modified polymer.
C = [(A−B) / A] * 100
A: Mass of polymer dissolved in solvent B: Mass of polymer after column treatment C: Mass% of modified polymer

[Synthesis of rare earth complex compounds]
The synthesis was performed according to the method described in Organometallics 1995, 14, 1107-1109. The raw materials used and Synthesis Examples 1 to 3 are described below.
Solvent: Tetrahydrofuran, n-hexane Rare earth salt: Anhydrous neodymium trichloride (manufactured by Aldrich)
: Anhydrous gadolinium trichloride (manufactured by Aldrich)
: Anhydrous yttrium trichloride (manufactured by Aldrich)
Dimethylamide lithium: Aldrich Lithium dimethylamide (5% hexane dispersion) filtered under nitrogen, dried and weighed a predetermined amount Trimethylaluminum: Kanto Chemical, 1M hexane solution Modifier 1: Synthesis The one synthesized according to Example 4 was used.
Denaturant 2: Aldrich, methyl N, N-dimethylaminopropionate was used.

(Synthesis example 1: neodymium complex compound)
Synthesis of Nd (thf) ₃ Cl ₃ The synthesis was performed in a nitrogen box. Anhydrous neodymium trichloride (4 g) was placed in a 200 mL Schlenk tube, tetrahydrofuran (25 mL) was added, and the mixture was stirred overnight at room temperature to obtain a tetrahydrofuran dispersion of the desired product Nd (thf) ₃ Cl ₃ (7.45 g).

Synthesis of Nd (NMe ₂ ) ₃ .LiCl ₃ Synthesis was performed in a nitrogen box. 2.6 g of dimethylamidolithium was dissolved in 50 mL of tetrahydrofuran. This tetrahydrofuran solution of dimethylamidolithium was slowly dropped into the above Nd (thf) ₃ Cl ₃ tetrahydrofuran dispersion over 2 hours in a nitrogen box, taking care not to rise above room temperature. After the reaction, the mixture was stirred overnight at room temperature, and then the solvent, tetrahydrofuran, was distilled off under reduced pressure to obtain 6 g of the desired product.

Synthesis of Nd [(μ-Me ₂ ) AlMe ₂ ] ₃ The synthesis was performed in a nitrogen box. Nd-hexane (23 mL) was added to Nd (NMe ₂ ) ₃ .LiCl ₃ to prepare a dispersion. To this dispersion, 125 mL of a 1M hexane solution of trimethylaluminum was slowly added dropwise over 2 hours, taking care that the reaction solution did not rise above room temperature. After the reaction, the mixture was stirred overnight at room temperature, and then the solvent n-hexane, unreacted trimethylaluminum and other by-products were distilled off to dryness under reduced pressure.

15-30 mL of n-hexane was added to the dried product and dispersed. This dispersion was filtered through a glass filter, and the insoluble matter was separated by filtration. The liquid after filtration was dried under reduced pressure by removing n-hexane to obtain 7.5 g of a crude product. 2-5 mL of n-hexane was added to this crude product, and after washing at −50 to −60 ° C., n-hexane was removed. This operation was repeated 4 times, and the fifth time, recrystallization was performed at −50 to −60 ° C. to remove n-hexane, followed by drying under reduced pressure to obtain 3.8 g of needle crystals. The position of the 10.56 ppm methyl group was confirmed from ¹ H-NMR, and it was confirmed that the target product was synthesized with good purity.

(Synthesis Example 2: Gadolinium Complex Compound)
Synthesis of Gd (thf) ₃ Cl ₃ The synthesis was performed in a nitrogen box. Anhydrous gadolinium trichloride (4 g) was placed in a 200 mL Schlenk tube, tetrahydrofuran (25 mL) was added, and the mixture was stirred overnight at room temperature to obtain a tetrahydrofuran dispersion of the desired product Gd (thf) ₃ Cl ₃ (7.45 g).

Synthesis of Gd (NMe ₂ ) ₃ .LiCl ₃ Synthesis was performed in a nitrogen box. 2.6 g of dimethylamidolithium was dissolved in 50 mL of tetrahydrofuran. This tetrahydrofuran solution of dimethylamidolithium was slowly dropped into the above Gd (thf) ₃ Cl ₃ tetrahydrofuran dispersion over 2 hours in a nitrogen box, taking care not to rise above room temperature. After the reaction, the mixture was stirred overnight at room temperature, and then the solvent, tetrahydrofuran, was distilled off under reduced pressure to obtain 6 g of the desired product.

Synthesis of Gd [(μ-Me ₂ ) AlMe ₂ ] ₃ The synthesis was performed in a nitrogen box. A dispersion was prepared by adding 23 mL of n-hexane to Gd (NMe ₂ ) ₃ .LiCl ₃ . To this dispersion, 125 mL of a 1M hexane solution of trimethylaluminum was slowly added dropwise over 2 hours, taking care that the reaction solution did not rise above room temperature. After the reaction, the mixture was stirred overnight at room temperature, and then the solvent n-hexane, unreacted trimethylaluminum and other by-products were distilled off to dryness under reduced pressure.

  15-30 mL of n-hexane was added to the reaction product and dispersed. This dispersion was filtered through a glass filter, and the insoluble matter was separated by filtration. The liquid after filtration was dried under reduced pressure by removing n-hexane to obtain 7.5 g of a crude product. 2-5 mL of n-hexane was added to this crude product, and after washing at −50 to 60 ° C., n-hexane was removed. This operation was repeated 4 times, and the fifth time, recrystallization was performed at −50 to 60 ° C. to remove n-hexane, followed by drying under reduced pressure to obtain 3.8 g of the desired product.

(Synthesis Example 3: Yttrium complex compound)
Synthesis of Y (thf) ₃ Cl ₃ The synthesis was performed in a nitrogen box. Anhydrous yttrium trichloride (4 g) was placed in a 200 mL Schlenk tube, tetrahydrofuran (25 mL) was added, and the mixture was stirred at room temperature overnight to obtain a tetrahydrofuran dispersion of the desired product Y (thf) ₃ Cl ₃ (7.45 g).

Synthesis of Y (NMe ₂ ) ₃ .LiCl ₃ Synthesis was performed in a nitrogen box. 2.6 g of dimethylamidolithium was dissolved in 50 mL of tetrahydrofuran. This tetrahydrofuran solution of dimethylamidolithium was slowly dropped into the above Y (thf) ₃ Cl ₃ tetrahydrofuran dispersion over 2 hours in a nitrogen box, taking care not to rise above room temperature. After the reaction, the mixture was stirred overnight at room temperature, and then the solvent, tetrahydrofuran, was distilled off under reduced pressure to obtain 6 g of the desired product.

Synthesis of Y [(μ-Me ₂ ) AlMe ₂ ] ₃ The synthesis was performed in a nitrogen box. A dispersion was prepared by adding 23 mL of n-hexane to Y (NMe ₂ ) ₃ .LiCl ₃ . To this dispersion, 125 mL of a 1M hexane solution of trimethylaluminum was slowly added dropwise over 2 hours, taking care that the reaction solution did not rise above room temperature. After the reaction, the mixture was stirred overnight at room temperature, and then the solvent n-hexane, unreacted trimethylaluminum and other by-products were distilled off to dryness under reduced pressure.

  15-30 mL of n-hexane was added to the reaction product and dispersed. This dispersion was filtered through a glass filter, and the insoluble matter was separated by filtration. The liquid after filtration was dried under reduced pressure by removing n-hexane to obtain 7.5 g of a crude product. 2-5 mL of n-hexane was added to this crude product, and after washing at −50 to 60 ° C., n-hexane was removed. This operation was repeated 4 times, and the fifth time, recrystallization was performed at −50 to 60 ° C. to remove n-hexane, followed by drying under reduced pressure to obtain 3.8 g of the desired product.

(Synthesis Example 4: Synthesis of Denaturant 1)
To 1 L of a 0.5 molar toluene solution of 1,3-bis (aminomethyl) cyclohexane, 5 times mole of ethyl bromoacetate with respect to 1,3-bis (aminomethyl) cyclohexane was added dropwise in an ice-water bath with stirring. Thereafter, 0.5 L of a 2 molar aqueous solution of potassium carbonate was added dropwise and reacted in a water bath for another 2 days. The organic phase was washed with ice-cold water, 0.4 L of 3N hydrochloric acid was added and transferred to the aqueous phase as an ammonium salt, and the aqueous phase was washed with ethyl acetate. Thereafter, 0.6 L of hexane, an aqueous solution of sodium hydroxide and sodium carbonate were added, and it was confirmed that no bubbles of carbon dioxide gas appeared. The organic phase was taken out, washed with cold water, and salted out with brine, followed by organic The phase was dried over anhydrous sodium sulfate. Thereafter, the organic phase was dried under reduced pressure with an evaporator to prepare tetraethyl ester of N, N, N ′, N′-tetrakiscarboxymethyl-1,3-bis (aminomethyl) cyclohexane, which was used as modifier 1. The structure of the obtained modifier 1 was confirmed by ¹ H-NMR. Further, when the purity was confirmed by gas chromatography, it was 99%. Gas chromatography was measured by increasing the oven temperature from 200 ° C. to 300 ° C. using column: ULTRA1 (manufactured by Agilent Technologies) and helium as a carrier. The molecular weight of the modifier 1 by GPC was about 550.

(Comparative Synthesis Example 1: Synthesis of Nd (Vers) ₃ )
Since Nd (Vers) ₃ is synthesized in an aqueous system, the raw material cyclohexane is not particularly purified. 2.9 g of versatic acid (C ₉ H ₁₉ COOH, Mw = 172.3) was dissolved in 300 mL of cyclohexane (special grade of Wako Pure Chemical) in a 1000 mL beaker. 0.6 g of sodium hydroxide was dissolved in 200 mL of water, added to the cyclohexane solution of versatic acid, and stirred for 2 hours. A white solid was precipitated and dissolved in the aqueous layer, and the aqueous layer turned white. Followed by _{NdCl 3 · 6H 2 O (2g} ) was dissolved in water 50 mL, was added to the beaker and stirred for 2 hours. When the aqueous layer became transparent and the organic layer turned purple, the inner solution was transferred to a 1000 mL separatory funnel. After the aqueous layer was separated, it was further washed twice with 100 mL of water, and 300 mL of cyclohexane was added to the inner solution and transferred to a 1000 mL eggplant flask. A Dean Stark trap and a Dimroth were attached to the eggplant flask, and refluxing was started while stirring in an oil bath. While removing the water deposited on the Dean-Stark trap, the bath was refluxed until the inside of the bath became transparent and the water content fell below 100 ppm. The solution in the flask was concentrated to 100 mL and transferred to a pressure bottle or a Schlenk tube, and then the system was degassed and purged with nitrogen. Titration of Nd was performed by the Cu-PAN method, and the concentration was determined to be 0.17 mol / L.

[Catalyst preparation]
All catalyst preparation operations were performed in a nitrogen box.
Solvent: Cyclohexane, n-hexane, and toluene were those obtained by purifying a commercially available dehydrated solvent (dehydrated cyclohexane, n-hexane manufactured by Kanto Chemical Co., Ltd., ultra-dehydrated toluene manufactured by Wako Pure Chemical Industries, Ltd.) by the above method.
Instruments: The instruments used (sample bottle, syringe, injection needle, stainless steel tube) were previously dried in a dryer at 100 ° C. for 24 hours.

(Catalyst preparation examples 1 to 4)
Nd [(μ-Me ₂ ) AlMe ₂ ] ₃ (40 mg) was dissolved in 20 mL of cyclohexane in a sample bottle. To this solution, 20 mL of methylaluminoxane (manufactured by Tosoh Finechem, T-MAO 211, 2.87 M, toluene solution) was added and stirred for 15 minutes. Thereafter, 9 mL of diisobutylaluminum hydride (Kanto Chemical Co., 1.0 M, hexane solution) was added and stirred for 5 minutes. Thereafter, 0.2 mL of diethylaluminum chloride (1M manufactured by Tosoh Finechem, hexane solution) was added, stirred for 15 minutes, and transferred to a stainless steel implantation tube. This was designated as Catalyst Composition 1. Catalyst compositions 1 to 4 were obtained in the same manner as in Catalyst Preparation Example 1 except that the amount was changed to the amount shown in Table 1.

(Catalyst preparation examples 5 to 6)
A catalyst composition 5 is obtained in the same manner as in Catalyst Preparation Example 1 except that Gd [(μ-Me ₂ ) AlMe ₂ ] ₃ is used instead of Nd [(μ-Me ₂ ) AlMe ₂ ] _3. It was. A catalyst composition 6 was obtained by the same operation as in Catalyst Preparation Example 5 except that the amount was changed to the amount shown in Table 1.

(Catalyst preparation example 7)
A catalyst composition 7 was obtained in the same manner as in Catalyst Preparation Example 1 except that Y [(μ-Me ₂ ) AlMe ₂ ] ₃ was used instead of Nd [(μ-Me ₂ ) AlMe ₂ ] ₃ . .

(Comparative catalyst preparation examples 1-2)
Cyclohexane 10 mL and butadiene 1 mL were placed in a pressure-resistant bottle that was previously purged with nitrogen, and a predetermined amount (see Table 2) of the cyclohexane solution of Nd (Vers) ₃ obtained in Comparative Synthesis Example 1 was added and mixed. A predetermined amount (see Table 2) of diisobutylaluminum hydride was added thereto and stirred for 5 minutes to react. Furthermore, a predetermined amount (see Table 2) of diethylaluminum chloride was added and reacted for 20 minutes to obtain a comparative catalyst composition 1. Comparative catalyst composition 2 was obtained by the same operation as Comparative catalyst preparation example 1 except that the amount was changed to the amount shown in Table 2.

[Examples 1 to 14]
(Polymerization process)
Cyclohexane and a 33% butadiene cyclohexane solution were added to a stainless steel 1.5 L autoclave so that the total amount became 750 g, and adjusted to a predetermined butadiene concentration. While stirring the monomer solution in an oil bath, the reactor internal temperature was adjusted to a predetermined temperature, and catalyst compositions 1 to 7 were pumped into the reactor with nitrogen using a stainless steel tube.

(Modification process)
After polymerization for a predetermined time, a predetermined amount of modifiers 1 and 2 was added and reacted at a predetermined temperature for a predetermined time. Thereafter, ethanol was added to stop the reaction. After extracting the polymer solution, it was washed 3 times with a 1N hydrochloric acid aqueous solution, reprecipitated with methanol, 0.1% of dibutylhydroxytoluene (BHT) was added and dried at 50 ° C. under vacuum. The experimental conditions and experimental results are listed in Table 1.

[Comparative Examples 1-4]
(Polymerization conditions)
Cyclohexane and a 33% butadiene cyclohexane solution were added to a stainless steel 1.5 L autoclave so that the total amount became 750 g, and adjusted to a predetermined butadiene concentration. While stirring the monomer solution in an oil bath, the reactor internal temperature was adjusted to a predetermined temperature. Comparative catalyst compositions 1 and 2 were fed into the reactor with nitrogen using a stainless steel tube.

(Modification process)
After polymerization for a predetermined time, a predetermined amount of the modifier 1 was added and reacted at a predetermined temperature for a predetermined time. Thereafter, ethanol was added to stop the reaction. After extracting the polymer solution, it was washed 3 times with a 1N hydrochloric acid aqueous solution, reprecipitated with methanol, 0.1% of dibutylhydroxytoluene (BHT) was added and dried at 50 ° C. under vacuum. Experimental conditions and results are listed in Table 2.

[Compound evaluation]
Ingredients are blended in the following proportions, set to a bath temperature of 130 ° C., using a pressure kneader D0.3-3, manufactured by Moriyama Co., as the first stage kneading, raw rubber, oil, silica, silane The coupling agents were added in order and kneaded for 4 minutes. Then, dumped out at about 160 ° C., passed through a roll, cooled, and then kneaded for 3 minutes by adding other raw materials excluding sulfur and vulcanization accelerator as second-stage kneading. And it dumped out at about 160 degreeC and rolled. At this time, the gathering of stock, the skin of the roll, and the edge were visually evaluated to compare the workability.
Processability:
As for the stock of stocks, “good” is the one that comes out as a lump, and “inferior” is the one that does not come out as a lump. The smooth and glossy roll skin was rated “good”, and the roll skin that was not smooth and glossy was rated “poor”. As for the edge, the smooth one was set as “good”, and the non-smooth one was set as “poor”.

  After cooling, sulfur and a vulcanization accelerator were added at 70 ° C. using a roll. Vulcanization was carried out at 170 ° C. for 12 minutes. The results of evaluating the performance of the obtained vulcanized rubber are shown in Table 3.

(Combination)
Modified conjugated diene polymers of Examples 2, 3, 12 and Comparative Examples 1 and 2: 70 parts by mass SBR (ASAPLENE E15 manufactured by Asahi Kasei Chemicals): 30 parts by mass Silica (Ultrazil VN3 manufactured by Evonik Degussa): 75 parts by mass Parts Silane coupling agent Si75 (Evonik Degussa): 6 parts by mass Carbon black N550 (Cabot Japan): 5 parts by weight SRAE oil (JOMO NC140): 20 parts by weight Wax (Ouchi Shinsei Chemical Co., Ltd.) Sannoc N): 1.5 parts by mass Anti-aging agent (Nocrack 6C manufactured by Ouchi Shinsei Chemical Co., Ltd.): 2 parts by mass Stearic acid (Lunac S-90 manufactured by Kao Corporation): 2 parts by mass Zinc Hana (manufactured by Sakai Chemical Co., Ltd.) : 2.5 parts by mass Sulfur (manufactured by Hosoi Chemical Co., Ltd.): 1.7 parts by mass Vulcanization accelerator CZ (Nouchira CZ- by Ouchi Shinsei Chemical Co., Ltd.) G): 1.7 parts by mass Vulcanization accelerator D (Noxeller DP manufactured by Ouchi Shinsei Chemical Co., Ltd.): 1.7 parts by mass

In addition, the performance evaluation method of vulcanized rubber was performed by the method shown next.
(1) Mooney viscosity:
The Mooney viscosity of the above-mentioned rubber compound before vulcanization was measured by using a Mooney viscometer and, according to JIS K6300-1, using an L-shaped rotor and preheating at 100 ° C. for 1 minute, then at 2 revolutions per minute. Spin and measure viscosity after 4 minutes. When the Mooney viscosity was a small value (75 or less), it was judged that the energy consumed during kneading was small and the processability was good.

(2) Viscoelasticity:
Using an ARES viscoelasticity tester manufactured by TA Instruments, tan δ was measured by changing the strain at a frequency of 10 Hz and at each measurement temperature (0 ° C. and 50 ° C.) by a torsion method. The higher the tan δ (loss tangent) measured at low temperature (0 ° C.) and strain 1%, the better the wet skid resistance, that is, the grip performance, and the tan δ (loss) measured at high temperature (50 ° C.) and strain 3%. It was judged that the lower the tangent), the smaller the hysteresis loss, and the lower the rolling resistance of the tire, that is, the better fuel economy.

  Further, the dispersibility of the filler was evaluated based on the difference ΔG ′ between G ′ when the strain at 50 ° C. is small (0.1%) and G ′ when the strain is large (10%). It was judged that the smaller the ΔG ′, the better the dispersibility of the filler.

(3) Akron wear:
The abrasion resistance was measured by using an Akron rubber abrasion tester manufactured by Yasuda Seiki Seisakusho and according to JIS K6264-2, the amount of abrasion of test method A, load 44.1N, and 3000 rotations. Evaluation was made with an index of Comparative Example 1 as 100. It was judged that the higher the index, the smaller the amount of wear and the better.

  The modified conjugated diene polymer of the present invention can be suitably used as a raw material rubber for tires. The rubber composition containing the modified conjugated diene polymer of the present invention can be used as a member for tire treads, sidewalls and other tires, and also for hoses, belts, shoe soles, window seals, other seals, and vibration damping It can also be used as a raw material for rubber and other industrial products.

Claims (10)

A polymerization step of polymerizing a conjugated diene monomer using a rare earth complex compound represented by the following formula (1) and / or (2) to obtain a conjugated diene polymer;
A modification step of obtaining a modified conjugated diene polymer by reacting the conjugated diene polymer with a compound capable of reacting with the conjugated diene polymer.
A method for producing a modified conjugated diene polymer.

(In the formulas (1) and (2), Ln represents any one selected from the group consisting of lanthanoid elements, Sc, and Y, and R ^{1 to} R ⁴ may be the same or different, and hydrogen Any one selected from the group consisting of an atom, an alkyl group having 1 to 8 carbon atoms, an alkylsilyl group, an alkyloxy group, a dialkylamide group, and an aryl group having 6 to 8 carbon atoms is shown.)   2. The polymerization step according to claim 1, wherein a reaction product of the rare earth complex compound and at least one compound selected from the group consisting of an alkylaluminum, an alkylaluminumoxy compound, and a borane compound is used. A method for producing a modified conjugated diene polymer.   The method for producing a modified conjugated diene polymer according to claim 1 or 2, wherein the compound capable of reacting with the conjugated diene polymer has a silyl group.   The method for producing a modified conjugated diene polymer according to any one of claims 1 to 3, wherein the compound capable of reacting with the conjugated diene polymer has a carbon-oxygen double bond.   The method for producing a modified conjugated diene polymer according to any one of claims 1 to 4, wherein the compound capable of reacting with the conjugated diene polymer has a carbon-nitrogen double bond.   The method for producing a modified conjugated diene polymer according to any one of claims 1 to 5, wherein the compound capable of reacting with the conjugated diene polymer has a cyclic structure containing oxygen.   The method for producing a modified conjugated diene polymer according to any one of claims 1 to 6, wherein the compound capable of reacting with the conjugated diene polymer has an amino group.   A modified conjugated diene polymer having a cis content of 98% or more and a modification rate of 20 wt% or more.   A modified conjugated diene polymer having a cis content of 94% or more and a modification rate of 40 wt% or more. A modified conjugated diene polymer obtained by the method for producing a modified conjugated diene polymer according to any one of claims 1 to 7,
A modified conjugated diene polymer composition comprising a filler.