JP6325362B2 - Rubber component, rubber composition containing rubber component, and tire using the rubber composition - Google Patents

Description

  The present invention relates to a rubber component, a rubber composition containing the rubber component, and a tire using the rubber composition.

In recent years, high durability of tires has been demanded in response to social demands for energy saving and resource saving. In addition, since the price of natural rubber is soaring, development of a synthetic rubber having durability comparable to that of natural rubber is required. In accordance with such demands, synthetic rubbers having excellent fracture resistance and wear resistance have been proposed.
As one of the solutions for improving the durability of tires using synthetic rubber, a technique for making a high cis structure of a homopolymer of isoprene polymerized using isoprene as a monomer has been proposed (for example, patents). Reference 1 and 2).
Further, in order to improve durability (breaking resistance and wear resistance), a polymer (at least one of synthetic polyisoprene and isoprene copolymer) having a high molecular weight having a number average molecular weight of 1.5 million or more is used as rubber. It is also disclosed that it is contained in a composition (for example, see Patent Document 3).

JP 2004-27179 A International Publication No. 2006-078021 Pamphlet JP 2013-185059 A

By the methods shown in Patent Documents 1 and 2, the elongation crystallinity was improved and the durability of the synthetic rubber was improved.
However, it has been clarified that a polymer having an isoprene skeleton is likely to be broken under a specific condition as compared with a polymer including other monomers. This can be cited as a cause of lowering the durability of the synthetic rubber. Also, when synthesizing isoprene polymers, if the end of the isoprene chain is modified with tin tetrachloride or titanium tetrachloride to increase the molecular weight with the aim of improving rubber properties, gelation is likely to occur. There was a case. When gelation occurs, the durability of the synthetic rubber is significantly reduced.
Further, even with the technique disclosed in Patent Document 3, a durable rubber comparable to natural rubber could not be obtained.
Thus, the durability of synthetic rubber still has a problem that it does not reach that of natural rubber.

The present invention provides an isoprene rubber component that is inferior to natural rubber in crack resistance and wear resistance even under conditions more severe than those currently required, and that is easier to process (good workability). The task is to do.
An object of the present invention is to provide a rubber component, a rubber composition, and a rubber composition that can obtain a crosslinked rubber composition having good processability (workability) before crosslinking and improved durability (crack resistance and wear resistance), and An object of the present invention is to provide a tire using the rubber composition.

The present inventors include a rubber component containing a polyisoprene polymer having a weight average molecular weight of 6,000,000 or more and a polyisoprene containing a polyisoprene polymer having a weight average molecular weight of 800,000 or less in a specific ratio. By including in the rubber composition, a crosslinked rubber composition having good workability of the rubber before crosslinking and improved durability (destructive property and abrasion resistance) than conventional synthetic rubber is obtained. As a result, the present invention has been completed.
That is, the present invention is configured as follows.

<1> Polystyrene polymer having a polystyrene equivalent weight average molecular weight of 6,000,000 or more measured by gel permeation chromatography is 10% by mass to 40% by mass, and polystyrene converted by gel permeation chromatography. A rubber component containing polyisoprene containing 5% by mass to 30% by mass of a polyisoprene polymer having a weight average molecular weight of 800,000 or less.
<2> The rubber component according to <1>, wherein the polyisoprene is a mixture of polyisoprene polymers or an isoprene homopolymer having a branched structure.
<3> The isoprene homopolymer having the branched structure contains 5% by mass to 30% by mass of an isoprene homopolymer having a polystyrene-equivalent weight average molecular weight of 8,000,000 or more by gel permeation chromatography measurement, and <2.
<4> The rubber component according to <2>, wherein the polyisoprene polymer has a 1,4-cis bond content of 90% or more.
<5> The rubber component according to <2> or <3>, wherein the polyisoprene homopolymer having a branched structure has a 1,4-cis bond content of 90% or more.

<6> The rubber component according to any one of <1> to <5>, wherein a total blending amount of the polyisoprene is 20% by mass to 100% by mass.

<7> A rubber composition comprising the rubber component according to any one of <1> to <6>.
<8> The rubber composition according to <7>, further comprising a filler, wherein the amount of the filler is 10 parts by mass to 75 parts by mass with respect to 100 parts by mass of all rubber components.

<9> A tire using the rubber composition according to <7> or <8>.
<10> A tire using the rubber composition according to <7> or <8> as a tread member.

  According to the present invention, a rubber component capable of obtaining a crosslinked rubber composition having good workability of rubber before crosslinking and improved durability (cracking resistance and wear resistance) compared to conventional synthetic rubbers, A rubber composition and a tire using the rubber composition can be provided.

《Rubber component》
The rubber component of the present invention contains 10% by mass to 40% by mass of a polyisoprene polymer having a polystyrene-equivalent weight average molecular weight of 6,000,000 or more as measured by gel permeation chromatography, and is measured by gel permeation chromatography. Polyisoprene containing 5 to 30% by mass of a polyisoprene polymer having a polystyrene-equivalent weight average molecular weight of 800,000 or less.
The polyisoprene having the above structure may be referred to as “polyisoprene of the present invention”.
In the present invention, unless otherwise specified, the weight average molecular weight of the polymer is the polystyrene equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) performed under the following conditions 1) to 3). Point to. The polystyrene-converted weight average molecular weight means a polystyrene-converted weight average molecular weight obtained from a calibration curve based on the peak top retention time of standard polystyrene having a known weight average molecular weight.
conditions:
1) Column: Showa Denko K.K., using two Shodex (registered trademark) KF807F 2) Eluent: Tetrahydrofuran 3) Measurement temperature: 40 ° C
The polyisoprene of the present invention may be a mixture of polyisoprene polymers, a polyisoprene homopolymer or a polyisoprene copolymer.

  When the rubber component of the present invention is mixed with a rubber composition, the low molecular weight component having a weight average molecular weight (Mw) of 800,000 or less has high fluidity in the rubber matrix portion and good processability, and the weight average molecular weight ( When the rubber composition contains a filler due to the ultra high molecular weight component having Mw) of 6 million or more, a sufficient network is formed between the fillers, and durability (cracking resistance and wear resistance) is improved. A crosslinked rubber composition can be obtained.

  In the present specification, “synthetic polyisoprene” means a homopolymer (homopolymer) of isoprene polymerized (synthesized) using isoprene as a monomer. In the present specification, the term “isoprene copolymer” means a copolymer (copolymer) of isoprene and a compound other than isoprene polymerized (synthesized) using isoprene and a compound other than isoprene as a monomer (monomer). Means. Both “synthetic polyisoprene” and “isoprene copolymer” include those obtained by modifying a part of the polymer polymer chain.

  When the polyisoprene of the present invention contains 10 mass% to 40 mass% of a polyisoprene polymer having a weight average molecular weight of 6,000,000 or more, the characteristics of the polymer can be sufficiently exhibited. Further, when the polyisoprene of the present invention contains 5% by mass to 30% by mass of a polyisoprene polymer having a weight average molecular weight of 800,000 or less, the rubber before crosslinking without lowering the durability of the resulting rubber composition The workability can be improved.

In the polyisoprene of the present invention, the polyisoprene polymer having a weight average molecular weight of 6,000,000 or more preferably has a weight average molecular weight of 8,000,000 to 10,000,000. When the weight average molecular weight is 8,000,000 or more, a crosslinked rubber composition having particularly improved durability (crack resistance and wear resistance) can be obtained. Further, when the weight average molecular weight is 10,000,000,000,000 or less, mixing of the macrogel can be suppressed in production.
The weight average molecular weight of the polyisoprene polymer having a weight average molecular weight of 800,000 or less is preferably 200,000 to 750,000. When the weight average molecular weight is 750,000 or less, the workability of the rubber composition is easily improved, and when it is 200,000 or more, the polymer is easily synthesized and the durability is hardly impaired.

  In addition, the polyisoprene rubber component is 10 masses of polyisoprene polymer having a weight average molecular weight of 6,000,000 or more in order to make the polyisoprene more durable and more workable than natural rubber. More preferably, the polyisoprene polymer having a weight average molecular weight of 800,000 or less is preferably contained in an amount of 20% by mass to 30% by mass.

The polyisoprene of the present invention is at least one of a polyisoprene polymer having a weight average molecular weight of more than 800,000 and a polyisoprene polymer having a weight average molecular weight of less than 6,000,000 as long as the effects of the present invention are not impaired. May be included.
The polyisoprene polymer exceeding 800,000 and the polyisoprene polymer having a weight average molecular weight of less than 6,000,000 are preferably 30% by mass to 85% by mass in the polyisoprene of the present invention, and 40% by mass. It is more preferable that it is% -80 mass%.

  The polyisoprene of the present invention can be obtained, for example, as a mixture in which polyisoprene polymers are mixed, or as an isoprene homopolymer having a branched structure in which isoprene polymers having different molecular weights are combined.

[Polyisoprene polymer mixture]
The polyisoprene polymer mixture is composed of a polyisoprene polymer having a weight average molecular weight of 6,000,000 or more and a polyisoprene polymer having a weight average molecular weight of 800,000 or less. It is obtained by mixing 5% by mass to 30% by mass of coalescence. Further, the mixture of polyisoprene polymers may further comprise at least one of a polyisoprene polymer exceeding 800,000 and a polyisoprene polymer having a weight average molecular weight of less than 6,000,000, based on the total amount of the mixture. It is preferable to mix 85 mass%.
Each polyisoprene polymer can be mixed by a known mixing method.
Moreover, the manufacturing method of each polyisoprene polymer is mentioned later.

[Isoprene homopolymer having a branched structure]
The isoprene homopolymer having a branched structure is composed of 10 mass% to 40 mass% of a polyisoprene polymer having a weight average molecular weight of 6,000,000 or more, and 5 mass% of a polyisoprene polymer having a weight average molecular weight of 800,000 or less. It is obtained by combining ˜30% by mass.
The isoprene homopolymer having a branched structure preferably further has a molecular weight distribution having the following characteristics.
That is, the isoprene homopolymer having a branched structure contains 5-30% by weight of an isoprene homopolymer having a weight average molecular weight of 8,000,000 or more, and isoprene homopolymer having a weight average molecular weight of 500,000 or less. It is preferable to contain 3 mass%-30 mass%. An isoprene homopolymer having a branched structure is obtained by combining an isoprene homopolymer having a weight average molecular weight of 8,000,000 or more and an isoprene homopolymer having a weight average molecular weight of 500,000 or less in the above-mentioned quantitative ratio. By having such a structure, it is easy to obtain a rubber component having good workability and durability comparable to natural rubber.
Hereinafter, a polyisoprene polymer used for a mixture of polyisoprene polymers, a method for producing the same, and a method for producing an isoprene homopolymer having a branched structure will be described.

<Polyisoprene polymer>
The polyisoprene polymer contained in the polyisoprene of the present invention is a synthetic polyisoprene or isoprene copolymer.
The polyisoprene polymer having a weight average molecular weight (Mw) of about 6 million and the polyisoprene polymer having a weight average molecular weight (Mw) of about 800,000 are, for example, first, second, or third polymerization catalyst compositions described later. The product can be obtained by polymerization at a low temperature (-50 ° C to 100 ° C) for a predetermined time (30 minutes to 2 days).

  Further, the molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer is not particularly limited and can be appropriately selected according to the purpose. 4.0 or less is preferable and 3.0 or less is more preferable. When the molecular weight distribution (Mw / Mn) is 4.0 or less, the physical properties can be made uniform. On the other hand, it is advantageous in terms of low exothermicity within the more preferable range. Here, the molecular weight distribution (Mw / Mn) is a weight average molecular weight (Mw) and a number average molecular weight as a polystyrene-converted average molecular weight using polystyrene as a standard substance by gel permeation chromatography (GPC) at a measurement temperature of 140 ° C. (Mn) is calculated and calculated from the calculated weight average molecular weight (Mw) and number average molecular weight (Mn).

The macrogel fraction in the polyisoprene polymer is preferably 5% or less, and more preferably 3% or less.
When the gel fraction in the polyisoprene polymer is 5% or less, a crosslinked rubber composition having improved durability (breakage resistance and wear resistance) can be obtained.
In addition, the polymer whose gel fraction in the polyisoprene polymer is 5% or less is, for example, a low temperature (−50 ° C. to 100 ° C.) using the first, second, or third polymerization catalyst composition described later. ) And polymerization for a predetermined time (30 minutes to 2 days).

[Synthetic polyisoprene]
(1,4-cis bond amount)
The amount of 1,4-cis bonds (sometimes referred to as cis-1,4 bonds) of the synthetic polyisoprene is preferably 90% or more, more preferably 95% or more, and particularly preferably 98% or more.
When the 1,4-cis bond amount is 90% or more, elongation crystallinity can be expressed, and when it is 95% or more, sufficient elongation crystallinity can be expressed.
On the other hand, when the 1,4-cis bond amount is in the more preferable range or in the particularly preferable range, it is advantageous in terms of improvement in durability due to stretched crystallinity.

(1,4-trans bond amount)
The 1,4-trans bond amount (sometimes referred to as trans-1,4 bond amount) of the synthetic polyisoprene is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10% or less. 5% or less is more preferable.
When the 1,4-trans bond amount is 5% or less, sufficient elongation crystallinity can be expressed.
On the other hand, when the 1,4-trans bond amount is in the more preferable range, it is advantageous in terms of improvement in durability due to stretched crystallinity.

(3,4-vinyl bond amount)
The 3,4-vinyl bond amount of the synthetic polyisoprene is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5% or less, and more preferably 2% or less.
When the 3,4-vinyl bond amount is 5% or less, sufficient elongation crystallinity can be expressed.
On the other hand, when the 3,4-vinyl bond amount is in the more preferable range, it is advantageous in terms of improvement in durability due to stretched crystallinity.

[Method for producing synthetic polyisoprene]
Next, a production method capable of producing synthetic polyisoprene will be described in detail. However, the manufacturing method described in detail below is merely an example. Synthetic polyisoprene can be produced by polymerizing isoprene as a monomer in the presence of a polymerization catalyst composition.

  The method for producing synthetic polyisoprene includes at least a polymerization step, and further includes a coupling step, a washing step, and other steps appropriately selected as necessary.

-Polymerization process-
The polymerization step is a step of polymerizing the isoprene monomer.
In the polymerization step, it is a monomer in the same manner as in the method for producing a polymer using a normal coordination ion polymerization catalyst, except that the first, second, or third polymerization catalyst composition described later is used. Isoprene can be polymerized. In the present invention, the polymerization catalyst composition used will be described in detail later.
As a catalyst in a polymerization process, the 1st, 2nd, or 3rd polymerization catalyst composition mentioned later can be used.

  As a polymerization method, any method 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. Moreover, when using a solvent for a polymerization reaction, the solvent used should just be inactive in a polymerization reaction, For example, toluene, cyclohexane, normal hexane, mixtures thereof etc. are mentioned.

  When the polymerization catalyst composition is used, for example, (1) a component of the polymerization catalyst composition is separately provided in a polymerization reaction system containing isoprene as a monomer, and polymerization is performed in the reaction system. A catalyst composition may be used, or (2) a polymerization catalyst composition prepared in advance may be provided in the polymerization reaction system. Moreover, (2) includes providing a metallocene complex (active species) activated by a cocatalyst.

  In the polymerization step, the polymerization may be stopped using a polymerization terminator such as methanol, ethanol, or isopropanol.

  In the polymerization step, the polymerization reaction of isoprene is preferably performed in an atmosphere of an inert gas, preferably nitrogen gas or argon gas. The polymerization temperature of the polymerization reaction is not particularly limited, but is preferably in the range of −100 ° C. to 200 ° C., for example, and can be about room temperature. If the polymerization temperature is raised, the cis-1,4 selectivity of the polymerization reaction may be lowered. The pressure for the polymerization reaction is preferably in the range of 0.1 MPa to 10.0 MPa in order to sufficiently incorporate isoprene into the polymerization reaction system. Also, the reaction time of the polymerization reaction is not particularly limited, and is preferably in the range of 1 second to 10 days, for example, but can be appropriately selected depending on conditions such as the type of catalyst and polymerization temperature.

（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）で表されるメタロセン錯体、及び下記一般式（II）： --- First polymerization catalyst composition ---
As a 1st polymerization catalyst composition (henceforth a 1st polymerization catalyst composition), following general formula (I):

(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. Group or a hydrogen atom, L represents a neutral Lewis base, w represents an integer of 0 to 3), and the following general formula (II):

（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）で表されるメタロセン錯体、並びに下記一般式（III）：

(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, and the following general formula (III ):

（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）で表されるハーフメタロセンカチオン錯体から
る群より選択される少なくとも１種類の錯体を含む重合触媒組成物が挙げられる。

(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. A polymerization catalyst composition containing at least one complex selected from the group consisting of half metallocene cation complexes represented by

The first polymerization catalyst composition may further contain other components contained in the polymerization catalyst composition containing a normal metallocene complex, such as a promoter. Here, the metallocene complex is a complex compound in which one or two or more cyclopentadienyls or derivatives thereof are bonded to the central metal. A certain metallocene complex may be called a half metallocene complex.
In the polymerization reaction system, the concentration of the complex contained in the first polymerization catalyst composition is preferably in the range of 0.1 mol / L to 0.0001 mol / L.

In the metallocene complexes represented by the general formulas (I) and (II), 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. Note that the two Cp ^Rs in the general formulas (I) and (II) may be the same or different from each other.

In the half metallocene cation complex represented by the general formula (III), Cp ^R ′ in the formula is unsubstituted or substituted cyclopentadienyl, indenyl or fluorenyl, and among these, unsubstituted or substituted indenyl Preferably there is. Cp ^R ′ having a cyclopentadienyl ring as a basic skeleton is represented by C ₅ H _5-X R _X. Here, X is an integer of 0-5. 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.

（式中、Ｒは水素原子、メチル基又はエチル基を示し、Ｍｅはメチル基を示す。）
一般式（III）において、インデニル環を基本骨格とするＣｐ^R’は、一般式（Ｉ）のＣｐ^Rと同様に定義され、好ましい例も同様である。

(In the formula, R represents a hydrogen atom, a methyl group or an ethyl group, and Me represents a methyl group.)
In the general formula (III), Cp ^R ′ having an indenyl ring as a basic skeleton is defined in the same manner as Cp ^{R in the} general formula (I), and preferred examples thereof are also the same.

In the general formula (III), Cp ^R ′ having a fluorenyl ring as a basic skeleton can be represented by C ₁₃ H _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 formulas (I), (II), and (III) 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 (I) contains a silylamide ligand [—N (SiR ₃ ) ₂ ]. The R groups contained in the silylamide ligand (R ^{a to} R ^f in the general formula (I)) 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. From the same viewpoint, it is more preferable that at least one of R ^{a to} R ^c is a hydrogen atom and at least one of R ^{d to} R ^f is a hydrogen atom. Furthermore, a methyl group is preferable as the alkyl group.

The metallocene complex represented by the general formula (II) contains a silyl ligand [—SiX ′ ₃ ]. X ′ contained in the silyl ligand [—SiX ′ ₃ ] is a group defined in the same manner as X in the general formula (III) described below, and preferred groups are also the same.

  In the general formula (III), 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 methoxy group, ethoxy group, propoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group; phenoxy group, 2,6-di- tert-butylphenoxy group, 2,6-diisopropylphenoxy group, 2,6-dineopentylphenoxy group, 2-tert-butyl-6-isopropylphenoxy group, 2-tert-butyl-6-neopentylphenoxy group, 2 Examples include aryloxide groups such as -isopropyl-6-neopentylphenoxy group, and among these, 2,6-di-tert-butylphenoxy group is preferable.

  In the general formula (III), the thiolate group represented by X is a thiomethoxy group, thioethoxy group, thiopropoxy group, thio n-butoxy group, thioisobutoxy group, thiosec-butoxy group, thiotert-butoxy group or the like Group thiolate group; thiophenoxy group, 2,6-di-tert-butylthiophenoxy group, 2,6-diisopropylthiophenoxy group, 2,6-dineopentylthiophenoxy group, 2-tert-butyl-6-isopropyl Arylthiolate groups such as thiophenoxy group, 2-tert-butyl-6-thioneopentylphenoxy group, 2-isopropyl-6-thioneopentylphenoxy group, 2,4,6-triisopropylthiophenoxy group, etc. Of these, 2,4,6-triisopropylthiophenoxy group is preferred. Arbitrariness.

  In the general formula (III), examples of the amide group represented by X include aliphatic amide groups such as dimethylamide group, diethylamide group, and diisopropylamide group; phenylamide group, 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 and 2,4,6-tri-tert-butylphenylamide group; and bistrialkylsilylamide groups such as bistrimethylsilylamide group. Among these, bistrimethylsilylamide Groups are preferred.

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

In the general formula (III), [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 is exemplified, and among these, tetrakis (pentafluorophenyl) borate is preferable.

  The metallocene complex represented by the general formula (I) and the formula (II) and the half metallocene cation complex represented by the general formula (III) further have 0 to 3, preferably 0 to 1 neutrality. Contains 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.

  In addition, the metallocene complex represented by the general formula (I) and the formula (II) and the half metallocene cation complex represented by the general formula (III) may exist as a monomer, It may be present as a higher multimer.

（式中、Ｘ''はハライドを示す。）
一般式（II）で表されるメタロセン錯体は、例えば、溶媒中でランタノイドトリスハライド、スカンジウムトリスハライド又はイットリウムトリスハライドを、インデニルの塩（例えばカリウム塩やリチウム塩）及びシリルの塩（例えばカリウム塩やリチウム塩）と反応させることで得ることができる。なお、反応温度は室温程度にすればよいので、温和な条件で製造することができる。また、反応時間は任意であるが、数時間〜数十時間程度である。反応溶媒は特に限定されないが、原料及び生成物を溶解する溶媒であることが好ましく、例えばトルエンを用いればよい。以下に、一般式（II）で表されるメタロセン錯体を得るための反応例を示す。 The metallocene complex represented by the general formula (I) 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 bis (trialkylsilyl) amide. It can obtain by making it react with salt (for example, potassium salt and 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 general formula (I) is shown.

(In the formula, X ″ represents a halide.)
The metallocene complex represented by the general formula (II) includes, for example, a lanthanide 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 a 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 example of reaction for obtaining the metallocene complex represented by general formula (II) is shown.

（式中、Ｘ''はハライドを示す。）

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

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

Here, in the compound represented by the 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 3 Indicates an integer. 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 general formula [A] ⁺ [B] ⁻ used for the above reaction is a compound selected and combined from the above non-coordinating anions and cations, which is N, N-dimethylaniline. Preference is given to nium tetrakis (pentafluorophenyl) borate, triphenylcarbonium tetrakis (pentafluorophenyl) borate and the like. In general formula [A] ⁺ [B] ^- ionic compounds represented by is preferably added 0.1-fold mol to 10 mols per mol of the metallocene complex, more preferably it added about 1 molar. When the half metallocene cation complex represented by the general formula (III) is used for the polymerization reaction, the half metallocene cation complex represented by the general formula (III) may be provided as it is in the polymerization reaction system, or the compound represented by the general formula (IV) and the general formula used in the reaction [a] ⁺ [B] ^- provides an ionic compound represented separately into the polymerization reaction system, in the reaction system, the general formula ( A half metallocene cation complex represented by III) may be formed. Further, by using a combination of the metallocene complex represented by the general formula (I) or the formula (II) and the ionic compound represented by the general formula [A] ⁺ [B] ⁻ , A half metallocene cation complex represented by the general formula (III) can also be formed.

  The structures of the metallocene complexes represented by the general formulas (I) and (II) and the half metallocene cation complex represented by the general formula (III) are preferably determined by X-ray structural analysis.

  The co-catalyst that can be used in the first polymerization catalyst composition can be arbitrarily selected from components used as a co-catalyst for a polymerization catalyst composition containing a normal metallocene complex. Suitable examples of the cocatalyst include aluminoxanes, organoaluminum compounds, and the above ionic compounds. These promoters may be used alone or in combination of two or more.

  The aluminoxane is preferably an alkylaluminoxane, and examples thereof include methylaluminoxane (MAO) and modified methylaluminoxane. As the modified methylaluminoxane, MMAO-3A (manufactured by Tosoh Finechem Co., Ltd.) and the like are preferable. The content of aluminoxane in the first polymerization catalyst composition is such that the element ratio Al / M between the central metal M of the metallocene complex and the aluminum element Al of the aluminoxane is about 10 to 1000, preferably about 100. It is preferable to do.

  On the other hand, as the organoaluminum compound, the general formula AlRR′R ″ (wherein R and R ′ are each independently a hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom, and R ″ is the number of carbon atoms). 1 to 10 hydrocarbon groups) are preferred. Examples of the organoaluminum compound include trialkylaluminum, dialkylaluminum chloride, alkylaluminum dichloride, and dialkylaluminum hydride. Among these, trialkylaluminum is preferable. Examples of the trialkylaluminum include triethylaluminum and triisobutylaluminum. In addition, it is preferable that content of the organoaluminum compound in a polymerization catalyst composition is 1 to 50 times mole with respect to a metallocene complex, and it is still more preferable that it is about 10 times mole.

  Furthermore, in the polymerization catalyst composition, the metallocene complex represented by the general formulas (I) and (II) and the half metallocene cation complex represented by the general formula (III) are combined with an appropriate promoter. Thus, the amount of 1,4-cis bond and the molecular weight of the resulting polymer can be increased.

--- Second polymerization catalyst composition ---
Next, the second polymerization catalyst composition (hereinafter also referred to as the second polymerization catalyst composition) will be described.
In addition, as the second polymerization catalyst composition,
(A) component: a rare earth element compound or a reaction product of the rare earth element compound and a Lewis base, the rare earth element compound or the reaction product having no bond between the rare earth element and carbon,
Component (B): Contains ionic compound (B-1) composed of non-coordinating anion and cation, aluminoxane (B-2), Lewis acid, complex compound of metal halide and Lewis base, and active halogen. A polymerization catalyst composition (hereinafter also referred to as a second polymerization catalyst composition) containing at least one selected from the group consisting of at least one halogen compound (B-3) among organic compounds can be preferably mentioned.
When the second polymerization catalyst composition contains at least one of the ionic compound (B-1) and the halogen compound (B-3), the polymerization catalyst composition further comprises:
(C) Component: The following general formula (X):
YR ¹ _a R ² _b R ³ _c (X)
[Wherein Y is a metal selected from Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R ¹ and R ² are the same or different and have 1 to 10 carbon atoms. R ³ is a hydrocarbon group or a hydrogen atom, and R ³ is a hydrocarbon group having 1 to 10 carbon atoms, provided that R ³ may be the same as or different from R ¹ or R ^2, and Y is a periodic table. When the metal is selected from Group 1, a is 1, and b and c are 0. When Y is a metal selected from Groups 2 and 12 of the Periodic Table, a And b is 1 and c is 0, and when Y is a metal selected from Group 13 of the Periodic Table, a, b and c are 1]. .

The second polymerization catalyst composition used in the production method is required to contain the component (A) and the component (B). Here, the polymerization catalyst composition contains the ionic compound (B-1) and the halogen compound ( In the case of containing at least one of B-3),
(C) Component: The following general formula (X):
YR ¹ _a R ² _b R ³ _c (X)
[Wherein Y is a metal selected from Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R ¹ and R ² are the same or different and have 1 to 10 carbon atoms. R ³ is a hydrocarbon group or a hydrogen atom, and R ³ is a hydrocarbon group having 1 to 10 carbon atoms, provided that R ³ may be the same as or different from R ¹ or R ^2, and Y is a periodic table. When the metal is selected from Group 1, a is 1, and b and c are 0. When Y is a metal selected from Groups 2 and 12 of the Periodic Table, a And b is 1 and c is 0, and when Y is a metal selected from Group 13 of the Periodic Table, a, b and c are 1]. It takes a thing.
Since the ionic compound (B-1) and the halogen compound (B-3) have no carbon atom to be supplied to the component (A), the component (C) is used as a carbon supply source to the component (A). Is required. In addition, even if it is a case where a polymerization catalyst composition contains an aluminoxane (B-2), this polymerization catalyst composition can contain (C) component. Further, the second polymerization catalyst composition may contain other components contained in a normal rare earth element compound-based polymerization catalyst composition, such as a promoter.
In the polymerization reaction system, the concentration of the component (A) contained in the second polymerization catalyst composition is preferably in the range of 0.0001 mol / l to 0.1 mol / l.

<(A) component>
The component (A) used in the second polymerization catalyst composition is a rare earth element compound or a reaction product of the rare earth element compound and a Lewis base, where the rare earth element compound and a reaction product of the rare earth element compound and a Lewis base are used. Does not have a bond between rare earth elements and carbon. When the rare earth element compound and the reactant do not have a rare earth element-carbon bond, the compound is stable and easy to handle. Here, the rare earth element compound is a compound containing a lanthanoid element or scandium or yttrium composed of the elements of atomic numbers 57 to 71 in the periodic table.
Specific examples of the lanthanoid element include lanthanium, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. In addition, (A) component may be used individually by 1 type, and may be used in combination of 2 or more type.

The rare earth element compound is preferably a divalent or trivalent salt or complex compound of a rare earth metal, and one or more ligands selected from a hydrogen atom, a halogen atom and an organic compound residue. More preferably, the rare earth element compound contains. Furthermore, the reaction product of the rare earth element compound or the rare earth element compound and the Lewis base is represented by the following general formula (XI) or (XII):
M ¹¹ X ¹¹ ₂ · L ¹¹ w (XI)
M ¹¹ X ¹¹ ₃ · L ¹¹ w (XII)
[Wherein, M ¹¹ represents a lanthanoid element, scandium or yttrium, and X ¹¹ independently represents a hydrogen atom, a halogen atom, an alkoxide group, a thiolate group, an amide group, a silyl group, an aldehyde residue, a ketone residue. A group, a carboxylic acid residue, a thiocarboxylic acid residue or a phosphorus compound residue, L ¹¹ represents a Lewis base, and w represents 0 to 3].

Specific examples of the group (ligand) bonded to the rare earth element of the rare earth element compound include a hydrogen atom; 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. An aliphatic alkoxy group such as a group; phenoxy group, 2,6-di-tert-butylphenoxy group, 2,6-diisopropylphenoxy group, 2,6-dineopentylphenoxy group, 2-tert-butyl-6-isopropyl Phenoxy group, 2-tert-butyl-6-neopentylphenoxy group, 2-isopropyl-6-neopentylphenoxy group; thiomethoxy group, thioethoxy group, thiopropoxy group, thio n-butoxy group, thioisobutoxy group, thiosec -Aliphatic thiolate groups such as butoxy and thio tert-butoxy; Si group, 2,6-di-tert-butylthiophenoxy group, 2,6-diisopropylthiophenoxy group, 2,6-dineopentylthiophenoxy group, 2-tert-butyl-6-isopropylthiophenoxy group, 2 Arylthiolate groups such as -tert-butyl-6-thioneopentylphenoxy, 2-isopropyl-6-thioneopentylphenoxy, 2,4,6-triisopropylthiophenoxy; dimethylamide, diethylamide, diisopropyl Aliphatic amide group such as amide group; phenylamide group, 2,6-di-tert-butylphenylamide group, 2,6-diisopropylphenylamide group, 2,6-dineopentylphenylamide group, 2-tert- Butyl-6-isopropylphenylamide group, 2-tert-butyl Arylamide groups such as 6-neopentylphenylamide group, 2-isopropyl-6-neopentylphenylamide group, 2,4,6-tert-butylphenylamide group; bistrialkylsilylamide groups such as bistrimethylsilylamide group; Silyl groups such as trimethylsilyl group, tris (trimethylsilyl) silyl group, bis (trimethylsilyl) methylsilyl group, trimethylsilyl (dimethyl) silyl group, triisopropylsilyl (bistrimethylsilyl) silyl group; fluorine atom, chlorine atom, bromine atom, iodine atom, etc. And the like. Furthermore, residues of aldehydes such as salicylaldehyde, 2-hydroxy-1-naphthaldehyde, 2-hydroxy-3-naphthaldehyde; 2′-hydroxyacetophenone, 2′-hydroxybutyrophenone, 2′-hydroxypropiophenone, etc. Residues of hydroxyphenone;
Residues of diketones such as acetylacetone, benzoylacetone, propionylacetone, isobutylacetone, valerylacetone, ethylacetylacetone; isovaleric acid, caprylic acid, octanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, olein Acid, linoleic acid, cyclopentanecarboxylic acid, naphthenic acid, ethylhexanoic acid, bivalic acid, versatic acid [trade name, manufactured by Shell Chemical Co., Ltd., a synthetic acid composed of a mixture of isomers of C10 monocarboxylic acid], Residues of carboxylic acids such as phenylacetic acid, benzoic acid, 2-naphthoic acid, maleic acid, succinic acid; residues of thiocarboxylic acids such as hexanethioic acid, 2,2-dimethylbutanethioic acid, decanethioic acid, thiobenzoic acid, Dibutyl phosphate, dipentyl phosphate, diphosphate Xyl, diheptyl phosphate, dioctyl phosphate, bis (2-ethylhexyl) phosphate, bis (1-methylheptyl) phosphate, dilauryl phosphate, dioleyl phosphate, diphenyl phosphate, bis (p-nonylphenyl) phosphate Bis (polyethylene glycol-p-nonylphenyl) phosphate, (butyl) phosphate (2-ethylhexyl), phosphate (1-methylheptyl) (2-ethylhexyl), phosphate (2-ethylhexyl) (p-nonyl) Residues of phosphate esters such as phenyl); 2-ethylhexylphosphonate monobutyl, 2-ethylhexylphosphonate mono-2-ethylhexyl, phenylphosphonate mono-2-ethylhexyl, 2-ethylhexylphosphonate mono-p-nonylphenyl, Phosphonic acid mono-2-ethylhexyl, phosphonic acid Non-1-methylheptyl, phosphonic acid ester residues such as phosphonic acid mono-p-nonylphenyl, dibutylphosphinic acid, bis (2-ethylhexyl) phosphinic acid, bis (1-methylheptyl) phosphinic acid, dilaurylphosphine Acid, dioleylphosphinic acid, diphenylphosphinic acid, bis (p-nonylphenyl) phosphinic acid, butyl (2-ethylhexyl) phosphinic acid, (2-ethylhexyl) (1-methylheptyl) phosphinic acid, (2-ethylhexyl) ( Residues of phosphinic acids such as p-nonylphenyl) phosphinic acid, butylphosphinic acid, 2-ethylhexylphosphinic acid, 1-methylheptylphosphinic acid, oleylphosphinic acid, laurylphosphinic acid, phenylphosphinic acid, p-nonylphenylphosphinic acid Raised It can also be gained. In addition, these ligands may be used individually by 1 type, and may be used in combination of 2 or more type.

As an example of the component (A) described above, trisbistrimethylsilylamidogadolinium Gd [N (SiMe ₃ ) ₂ ] ₃ can be suitably used.

In the component (A) used in the second polymerization catalyst composition, examples of the Lewis base that reacts with the rare earth element compound include tetrahydrofuran, diethyl ether, dimethylaniline, trimethylphosphine, lithium chloride, bis (2-diphenylphosphinophenyl). Examples include amines, neutral olefins, and neutral diolefins. Of these, bis (2-diphenylphosphinophenyl) amine is preferred.
Here, when the rare earth element compound reacts with a plurality of Lewis bases (in the formulas (XI) and (XII), when w is 2 or 3), the Lewis base L ¹¹ is the same or different. May be.

<(B) component>
The component (B) used in the second polymerization catalyst composition is at least one compound selected from the group consisting of an ionic compound (B-1), an aluminoxane (B-2), and a halogen compound (B-3). . In addition, it is preferable that content of the sum total of (B) component in a 2nd polymerization catalyst composition is 0.1 times mole-50 times mole with respect to (A) component.

((B-1) component)
The ionic compound represented by (B-1) is composed of a non-coordinating anion and a cation, and reacts with a rare earth element compound as a component (A) or a reaction product thereof with a Lewis base to form a cationic transition metal. Examples thereof include ionic compounds capable of generating a compound. Here, as the non-coordinating anion, for example, 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-dicarboundecaborate and the like can be mentioned. 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 trisubstituted carbonium cations such as triphenylcarbonium cation and tri (substituted phenyl) carbonium cation, and more specifically, as tri (substituted phenyl) carbonyl cation, Examples include 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 Is mentioned. Specific examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tri (methylphenyl) phosphonium cation, and tri (dimethylphenyl) phosphonium cation.
The ionic compound is preferably a compound selected and combined from the above-mentioned non-coordinating anions and cations. Specifically, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, triphenylcarbonium tetrakis. (Pentafluorophenyl) borate and the like are preferable. Moreover, these ionic compounds can be used individually by 1 type, or 2 or more types can be mixed and used for them. In addition, it is preferable that it is 0.1 times mole-10 times mole with respect to (A) component, and, as for content of the ionic compound in a 2nd polymerization catalyst composition, it is more preferable that it is about 1 time mole.

((B-2) component)
The aluminoxane represented by (B-2) is a compound obtained by bringing an organoaluminum compound and a condensing agent into contact with each other. For example, the repeating unit represented by the general formula: (—Al (R ′) O—) A chain aluminoxane or cyclic aluminoxane having the formula (wherein R ′ is a hydrocarbon group having 1 to 10 carbon atoms, and some of the hydrocarbon groups may be substituted with a halogen atom and / or an alkoxy group; The polymerization degree is preferably 5 or more, more preferably 10 or more. Here, specific examples of R ′ include a methyl group, an ethyl group, a propyl group, and an isobutyl group. Among these, a methyl group is preferable. Examples of the organoaluminum compound used as an aluminoxane raw material include trialkylaluminums such as trimethylaluminum, triethylaluminum, and triisobutylaluminum, and mixtures thereof, and trimethylaluminum is particularly preferable. For example, an aluminoxane using a mixture of trimethylaluminum and tributylaluminum as a raw material can be preferably used. The content of the aluminoxane in the second polymerization catalyst composition is such that the element ratio Al / M of the rare earth element M constituting the component (A) and the aluminum element Al of the aluminoxane is about 10 to 1000. It is preferable.

((B-3) component)
The halogen compound represented by (B-3) comprises at least one of a Lewis acid, a complex compound of a metal halide and a Lewis base, and an organic compound containing an active halogen. For example, the rare earth element as the component (A) By reacting with a compound or a reactant thereof with a Lewis base, a cationic transition metal compound, a halogenated transition metal compound, or a compound in which the transition metal center is insufficiently charged can be generated. In addition, it is preferable that content of the sum total of the halogen compound in a 2nd polymerization catalyst composition is 1 time mole-5 times mole with respect to (A) component.

As the Lewis acid, boron-containing halogen compounds such as B (C ₆ F ₅ ) ₃ and aluminum-containing halogen compounds such as Al (C ₆ F ₅ ) ₃ can be used. A halogen compound containing an element belonging to Group VI or VIII can also be used. Preferably, aluminum halide or organometallic halide is used. Moreover, as a halogen element, chlorine or bromine is preferable. Specific examples of Lewis acids include methyl aluminum dibromide, methyl aluminum dichloride, ethyl aluminum dibromide, ethyl aluminum dichloride, butyl aluminum dibromide, butyl aluminum dichloride, dimethyl aluminum bromide, dimethyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum Chloride, dibutylaluminum bromide, dibutylaluminum chloride, methylaluminum sesquibromide, methylaluminum sesquichloride, ethylaluminum sesquibromide, ethylaluminum sesquichloride, dibutyltin dichloride, aluminum tribromide, antimony trichloride, antimony pentachloride, phosphorus trichloride, Phosphorus pentachloride Tin tetrachloride, titanium tetrachloride, tungsten hexachloride and the like. Among these, diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum bromide, ethylaluminum sesquichloride bromide, ethyl aluminum dibromide particularly preferred.

  The metal halide composing the complex of metal halide and Lewis base is beryllium chloride, beryllium bromide, beryllium iodide, magnesium chloride, magnesium bromide, magnesium iodide, calcium chloride, calcium bromide, iodide. Calcium, 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, odor Manganese iodide, 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. Among these, magnesium chloride, calcium chloride, barium chloride, manganese chloride, zinc chloride, copper chloride are preferable, Magnesium, manganese chloride, zinc chloride, copper chloride being particularly preferred.

  Moreover, as a Lewis base which comprises the complex compound of a metal halide and a Lewis base, a phosphorus compound, a carbonyl compound, a nitrogen compound, an ether compound, alcohol, etc. are preferable. Specifically, tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate, triethylphosphine, tributylphosphine, triphenylphosphine, diethylphosphinoethane, diphenylphosphinoethane, acetylacetone, benzoylacetone , Propionitrile acetone, valeryl acetone, ethyl acetylacetone, methyl acetoacetate, ethyl acetoacetate, phenyl acetoacetate, dimethyl malonate, diethyl malonate, diphenyl malonate, acetic acid, octanoic acid, 2-ethyl-hexanoic acid, olein Acid, stearic acid, benzoic acid, naphthenic acid, versatic acid, triethylamine, N, N-dimethylacetamide, tetrahydrofuran, diphenyl ether, 2-ethyl-hexyl alcohol Examples include oleyl alcohol, stearyl alcohol, phenol, benzyl alcohol, 1-decanol, and lauryl alcohol. Among these, 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 mol to 30 mol, preferably 0.5 mol to 10 mol, per mol of metal halide. When the reaction product with the Lewis base is used, the metal remaining in the polymer can be reduced.
Examples of the organic compound containing active halogen include benzyl chloride.

((C) component)
Component (C) used in the second polymerization catalyst composition has the following general formula (X):
YR ¹ _a R ² _b R ³ _c (X)
[Wherein Y is a metal selected from Group 1, Group 2, Group 12 and Group 13 of the Periodic Table, and R ¹ and R ² are the same or different and have 1 to 10 carbon atoms. R ³ is a hydrocarbon group or a hydrogen atom, and R ³ is a hydrocarbon group having 1 to 10 carbon atoms, provided that R ³ may be the same as or different from R ¹ or R ^2, and Y is a periodic table. When the metal is selected from Group 1, a is 1, and b and c are 0. When Y is a metal selected from Groups 2 and 12 of the Periodic Table, a And b is 1 and c is 0, and when Y is a metal selected from Group 13 of the Periodic Table, a, b and c are 1]. The following general formula (Xa):
AlR ¹ R ² R ³ (Xa)
[Wherein, R ¹ and R ² are the same or different and are a hydrocarbon group or a hydrogen atom having 1 to 10 carbon atoms, and R ³ is a hydrocarbon group having 1 to 10 carbon atoms, provided that R ³ is R ^It may be the same as or different from ¹ or R ² ].

  Examples of the organoaluminum compound represented by the general formula (X) include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-t-butylaluminum, and tripentylaluminum. , 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, diiso hydrogenated Hexyl aluminum, dioctyl aluminum hydride, diisooctyl aluminum hydride; ethyl aluminum dihydride, n-propyl aluminum Muzi hydride, isobutylaluminum dihydride and the like. Among these, triethylaluminum, triisobutylaluminum, hydrogenated diethylaluminum, hydrogenated diisobutylaluminum are preferred. The organoaluminum compound as component (C) described above can be used alone or in combination of two or more. In addition, it is preferable that it is 1 times-50 times mole with respect to (A) component, and, as for content of the organoaluminum compound in a 2nd polymerization catalyst composition, it is more preferable that it is about 10 times mole.

--- Third polymerization catalyst composition ---
The third polymerization catalyst composition (hereinafter also referred to as the third polymerization catalyst composition) includes the following metallocene composite catalyst and a boron anion, and further includes a normal metallocene catalyst. It is preferable to include other components contained in the polymerization catalyst composition, such as a promoter. The metallocene composite catalyst and the boron anion are also referred to as a two-component catalyst. According to the third polymerization catalyst composition, since the boron anion is further contained in the same manner as the metallocene composite catalyst, the content of each monomer component in the polymer can be arbitrarily controlled. .

---- Metallocene catalyst ----
The metallocene composite catalyst has the following formula (A):
R _a MX _b QY _b (A)
[In the formula, each R independently represents an unsubstituted or substituted indenyl, the R is coordinated to M, M represents a lanthanoid element, scandium or yttrium; 20 represents a hydrocarbon group, X is μ-coordinated to M and Q, Q represents a group 13 element of the periodic table, and Y independently represents a hydrocarbon group having 1 to 20 carbon atoms or Represents a hydrogen atom, Y is coordinated to Q, and a and b are 2.
In a preferred example of the metallocene composite catalyst, the following formula (XV):

［式中、Ｍ¹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及びＲ^Bは、それぞれ独立して炭素数１〜２０の炭化水素基を示し、該Ｒ^A及びＲ^Bは、Ｍ¹及びＡｌにμ配位しており、Ｒ^C及びＲ^Dは、それぞれ独立して炭素数１〜２０の炭化水素基又は水素原子を示す］で表されるメタロセン系複合触媒が挙げられる。

[ ^Wherein , M ¹ represents a lanthanoid element, scandium or yttrium, Cp ^R independently represents unsubstituted or substituted indenyl, and R ^A and R ^B each independently represents a group having 1 to 20 carbon atoms. R ^A and R ^B are μ-coordinated to M ¹ and Al, and R ^C and R ^D each independently represent a hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom. Metallocene composite catalysts represented by

  By using a metallocene polymerization catalyst, a polymer can be produced. In addition, by using a metallocene composite catalyst, for example, a catalyst previously combined with an aluminum catalyst, the amount of alkylaluminum used during polymer synthesis can be reduced or eliminated. If a conventional catalyst system is used, it is necessary to use a large amount of alkylaluminum at the time of polymer synthesis. For example, in the conventional catalyst system, it is necessary to use 10 equivalents or more of alkylaluminum with respect to the metal catalyst. If the metallocene composite catalyst is used, an excellent catalytic action can be obtained by adding about 5 equivalents of alkylaluminum. Demonstrated.

  In the metallocene composite catalyst, the metal M in the formula (A) 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 metal M include samarium Sm, neodymium Nd, praseodymium Pr, gadolinium Gd, cerium Ce, holmium Ho, scandium Sc, and yttrium Y.

  In the formula (A), each R is independently an unsubstituted indenyl or a substituted indenyl, and the R is coordinated to the metal M. Specific examples of the substituted indenyl group include 1,2,3-trimethylindenyl group, heptamethylindenyl group, 1,2,4,5,6,7-hexamethylindenyl group, and the like. It is done.

  In the formula (A), Q represents a group 13 element in the periodic table, and specific examples include boron, aluminum, gallium, indium, and thallium.

  In the formula (A), each X independently represents a hydrocarbon group having 1 to 20 carbon atoms, and the X is μ-coordinated to M and Q. Here, as a C1-C20 hydrocarbon group, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group , Pentadecyl group, hexadecyl group, heptadecyl group, stearyl group and the like. Note that the μ coordination is a coordination mode having a crosslinked structure.

  In the formula (A), each Y independently represents a hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom, and the Y is coordinated to Q. Here, as a C1-C20 hydrocarbon group, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group , Pentadecyl group, hexadecyl group, heptadecyl group, stearyl group and the like.

In the formula (XV), the metal M ¹ 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 metal M ¹ include samarium Sm, neodymium Nd, praseodymium Pr, gadolinium Gd, cerium Ce, holmium Ho, scandium Sc, and yttrium Y.

In the formula (XV), Cp ^R 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. Incidentally, the two Cp ^R in the formula (XV) may each be the same or different from each other.

In the formula (XV), R ^A and R ^B each independently represent a hydrocarbon group having 1 to 20 carbon atoms, said R ^A and R ^B is coordinated μ to M ¹及A ^l. Here, as a C1-C20 hydrocarbon group, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group , Pentadecyl group, hexadecyl group, heptadecyl group, stearyl group and the like. Note that the μ coordination is a coordination mode having a crosslinked structure.

In the formula (XV), R ^C and R ^D are each independently a hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom. Here, as a C1-C20 hydrocarbon group, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group , Pentadecyl group, hexadecyl group, heptadecyl group, stearyl group and the like.
The metallocene composite catalyst is, for example, in a solvent, represented by the following formula (XVI):

（式中、Ｍ²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^E〜Ｒ^J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）で表されるメタロセン錯体を、ＡｌＲ^KＲ^LＲ^Mで表される有機アルミニウム化合物と反応させることで得られる。なお、反応温度は室温程度にすればよいので、温和な条件で製造することができる。また、反応時間は任意であるが、数時間〜数十時間程度である。反応溶媒は特に限定されないが、原料及び生成物を溶解する溶媒であることが好ましく、例えばトルエンやヘキサンを用いればよい。なお、メタロセン系複合触媒の構造は、¹Ｈ−ＮＭＲやＸ線構造解析により決定することが好ましい。

(In the formula, M ² represents a lanthanoid element, scandium or yttrium, Cp ^R each independently represents an unsubstituted or substituted indenyl group, and R ^{E to} R ^J each independently represents a group having 1 to 3 carbon atoms. an alkyl group or a hydrogen atom, L is a neutral Lewis base, w is, the metallocene complex represented by an integer of 0 to 3), an organoaluminum compound represented by AlR ^K R ^L R ^M It is obtained by reacting with. 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 or hexane may be used. The structure of the metallocene composite catalyst is preferably determined by ¹ H-NMR or X-ray structural analysis.

In the metallocene complex represented by the formula (XVI), Cp ^R is unsubstituted indenyl or substituted indenyl, and has the same meaning as Cp ^R in the formula (XV). In the formula (XVI), the metal M ² is a lanthanoid element, scandium or yttrium, and has the same meaning as the metal M ¹ in the formula (XV).

The metallocene complex represented by the formula (XVI) contains a silylamide ligand [—N (SiR ₃ ) ₂ ]. The R groups (R ^{E to} R ^J groups) contained in the silylamide ligand 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 ^{E to} R ^J is a hydrogen atom. By making at least one of R ^{E to} R ^J a hydrogen atom, the catalyst can be easily synthesized. Furthermore, a methyl group is preferable as the alkyl group.

  The metallocene complex represented by the formula (XVI) further contains 0 to 3, preferably 0 to 1 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 formula (XVI) may exist as a monomer, or may exist as a dimer or a multimer higher than that.

On the other hand, the organoaluminum compound used for the production of the metallocene composite catalyst is represented by AlR ^K R ^L R ^M , where R ^K and R ^L are each independently a monovalent hydrocarbon having 1 to 20 carbon atoms. R ^M is a group or hydrogen atom, and R ^M is a monovalent hydrocarbon group having 1 to 20 carbon atoms, provided that R ^M may be the same as or different from R ^K or R ^L. Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a tridecyl group, and a tetradecyl group. , Pentadecyl group, hexadecyl group, heptadecyl group, stearyl group and the like.

  Specific examples of organoaluminum compounds include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-t-butylaluminum, tripentylaluminum, 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, Dioctyl aluminum hydride, diisooctyl aluminum hydride; ethyl aluminum dihydride, n-propyl aluminum di Idoraido, include isobutyl aluminum dihydride and the like, among these, triethylaluminum, triisobutylaluminum, hydrogenated diethylaluminum, hydrogenated diisobutylaluminum are preferred. Moreover, these organoaluminum compounds can be used individually by 1 type, or 2 or more types can be mixed and used for them. In addition, the amount of the organoaluminum compound used for the production of the metallocene composite catalyst is preferably 1 to 50 times mole, more preferably about 10 times mole to the metallocene complex.

  In the third polymerization catalyst composition, specific examples of the boron anion constituting the two-component catalyst include a tetravalent boron anion. For example, tetraphenylborate, tetrakis (monofluorophenyl) borate, tetrakis (difluorophenyl) borate, tetrakis (trifluorophenyl) borate, tetrakis (tetrafluorophenyl) borate, tetrakis (pentafluorophenyl) borate, tetrakis (tetrafluoromethyl) Phenyl) borate, tetra (tolyl) borate, tetra (xylyl) borate, (triphenyl, pentafluorophenyl) borate, [tris (pentafluorophenyl), phenyl] borate, tridecahydride-7,8-dicarboundecaborate Among these, tetrakis (pentafluorophenyl) borate is preferable.

  The boron anion can be used as an ionic compound combined with a cation. Examples of the cation 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. Therefore, as the ionic compound, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, triphenylcarbonium tetrakis (pentafluorophenyl) borate and the like are preferable. The ionic compound composed of a boron anion and a cation is preferably added in an amount of 0.1-fold to 10-fold, more preferably about 1-fold, with respect to the metallocene composite catalyst.

  In the third polymerization catalyst composition, it is necessary to use a metallocene composite catalyst and a boron anion. In the reaction system for reacting the metallocene catalyst represented by the formula (XVI) with an organoaluminum compound, a boron anion is used. Is present, the metallocene composite catalyst of the formula (XV) cannot be synthesized. Therefore, for the preparation of the third polymerization catalyst composition, it is necessary to synthesize the metallocene composite catalyst in advance, isolate and purify the metallocene composite catalyst, and then combine with the boron anion.

The cocatalyst can be used in the third polymerization catalyst composition, for example, other organic aluminum compound represented by AlR ^K R ^L R ^M described above, aluminoxane can be preferably used. The aluminoxane is preferably an alkylaminoxan, and examples thereof include methylaluminoxane (MAO) and modified methylaluminoxane. As the modified methylaluminoxane, MMAO-3A (manufactured by Tosoh Finechem Co., Ltd.) and the like are preferable. These aluminoxanes may be used alone or in combination of two or more.

--Coupling step 1--
The coupling step 1 is a step in which at least a part (for example, terminal) of the polymer chains of the synthetic polyisoprene obtained in the polymerization step is subjected to a coupling reaction.
In the coupling step 1, it is preferable to perform a coupling reaction (reaction for modifying the terminal of the polymer chain) when the polymerization reaction reaches 100%.
There is no restriction | limiting in particular as a coupling agent used for a coupling reaction, According to the objective, it can select suitably, For example, (i) tin content, such as bis (1-octadecyl maleate) dioctyl tin (IV), etc. Compounds, (ii) isocyanate compounds such as 4,4′-diphenylmethane diisocyanate, (iii) alkoxysilane compounds such as glycidylpropyltrimethoxysilane, and the like. These may be used individually by 1 type and may use 2 or more types together.
Among these, bis (-1-octadecyl maleate) dioctyltin (IV) is preferable in terms of reaction efficiency and low gel formation.
In addition, by performing a coupling reaction, it is possible to achieve a high molecular weight by bonding polymer chains together, and also to prevent degradation other than hydrolysis and to reduce the number average molecular weight (Mn). Can be suppressed.

There is no restriction | limiting in particular as reaction temperature in a coupling reaction, Although it can select suitably according to the objective, 10 to 100 degreeC is preferable and 20 to 80 degreeC is more preferable.
When the reaction temperature is 10 ° C. or higher, the reaction rate can be prevented from significantly decreasing, and when the reaction temperature is 100 ° C. or lower, the polymer can be prevented from gelling.
There is no restriction | limiting in particular as reaction time in a coupling reaction, Although it can select suitably according to the objective, 10 minutes-1 hour are preferable.

  When the reaction time is 10 minutes or longer, the reaction can be sufficiently carried out, and when it is 1 hour or shorter, the polymer can be prevented from gelling.

-Cleaning process-
The washing step is a step of washing the polyisoprene obtained in the polymerization step. In addition, there is no restriction | limiting in particular as a medium used for washing | cleaning, According to the objective, it can select suitably, For example, methanol, ethanol, isopropanol, etc. are mentioned.

<Method for producing isoprene homopolymer having a branched structure>
The isoprene homopolymer having a branched structure having the above-described molecular weight distribution characteristics (hereinafter sometimes referred to as the branched isoprene homopolymer of the present invention) may be produced by a method for producing synthetic polyisoprene, From the viewpoint of easy acquisition of the characteristics of the molecular weight distribution of the present invention, it is preferably produced by the following production method.
That is, the method for producing the branched isoprene homopolymer of the present invention comprises:
(A) a polymerization step of polymerizing a homopolymer of isoprene using isoprene as a monomer;
It is preferable to have a coupling step (coupling step 2) for coupling at least part of the polymer chains of the isoprene homopolymer obtained in the polymerization step to each other.

The production method of the branched isoprene homopolymer of the present invention is more preferably the following embodiment. That is,
(B) a modification reaction in which the coupling step (coupling step 2) modifies at least part of the polymer chain of the isoprene homopolymer with an organosilicon compound having an alkoxy group;
It is preferable to have a condensation coupling reaction in which the alkoxy groups of the modified isoprene homopolymer modified with the organosilicon compound by the modification reaction are subjected to condensation coupling using water and a condensation catalyst.
Furthermore, (c) it is preferable that the reaction temperature in the condensation coupling reaction is 10 ° C. or more and 100 ° C. or less, and the reaction time is 10 minutes or more and 1 hour or less.
It is preferable that the manufacturing method of the isoprene homopolymer which has a branched structure is comprised by the combination of (a)-(c).

  The branched isoprene homopolymer production method of the present invention performs the following coupling step 2 instead of the coupling step 1 in the synthetic polyisoprene production method.

--Coupling process 2--
In the coupling step 2, when the polymerization reaction reaches 100%, it is preferable to first perform a modification reaction (a reaction for modifying at least a part of the polymer chain). The modifying agent used in the modification reaction is not particularly limited and can be appropriately selected according to the purpose. In order to obtain the above, it is preferable to use an organosilicon compound having an alkoxy group in the modification reaction, and particularly an organosilicon compound having two alkoxy groups.
Examples of organosilicon compounds having two alkoxy groups include vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethylmethyldimethoxysilane, and 2- (3,4-epoxycyclohexyl) ethylmethyl. Diethoxysilane, 3-glycidoxymethyldimethoxysilane, 3-glycidoxymethyldiethoxysilane, p-styrylmethyldimethoxysilane, p-styrylmethyldiethoxysilane, 3-methacryloxymethyldimethoxysilane, 3-methacryloxy Methyldiethoxysilane, 3-methacryloxymethyldimethoxysilane, 3-methacryloxymethyldiethoxysilane, 3-acryloxymethyldimethoxysilane, 3-acryloxymethyldiethoxysilane, 3- (methyldimethoxysilane) Lil)-N-(1,3-dimethyl - butylidene) propylamine, 3- (methyldiethoxysilyl)-N-(1,3-dimethyl - butylidene) propylamine, and the like. These may be used individually by 1 type and may use 2 or more types together.
Among these, 3-glycidoxymethyldimethoxysilane and 3-glycidoxymethyldiethoxysilane are more preferable in terms of reaction efficiency and low gel formation.

In order to obtain the branched isoprene homopolymer of the present invention, it is preferable to further react a polymer modified with an organosilicon compound having an alkoxy group. In order to obtain the branched isoprene homopolymer of the present invention, water and a condensation catalyst are further added to the polymer solution, the alkoxy groups of the modified organosilicon compound are condensed with each other, and a coupling reaction is performed. High molecular weight and branching can be achieved, and low gel formation can be suppressed.
There is no restriction | limiting in particular as a condensation catalyst used in combination with water when performing a condensation coupling reaction in a solution, Although it can select suitably according to the objective, A tin containing compound is preferable. Examples of the tin-containing compound include tin-containing compounds such as dibutyltin diacetate, dibutyltin dilaurate, and bis (-1-octadecyl maleate) dioctyltin (IV). These may be used individually by 1 type and may use 2 or more types together.
Further, an amine compound such as butylamine or pyridine may be used in combination as a cocatalyst.

  There is no restriction | limiting in particular as reaction temperature in a condensation coupling reaction, Although it can select suitably according to the objective, 10 to 100 degreeC is preferable and 20 to 80 degreeC is more preferable. When the reaction temperature is 10 ° C. or higher, the reaction rate can be prevented from significantly decreasing, and when the reaction temperature is 100 ° C. or lower, the polymer can be prevented from gelling.

There is no restriction | limiting in particular as reaction time in a coupling reaction, Although it can select suitably according to the objective, 10 minutes-1 hour are preferable.
When the reaction time is 10 minutes or longer, the reaction can be sufficiently performed, and when it is 1 hour or shorter, the polymer can be prevented from gelling.

[Isoprene copolymer]
(Compounds other than isoprene)
The compound other than the isoprene to be copolymerized with isoprene is not particularly limited and may be appropriately selected depending on the purpose. For example, 1,3-butadiene, 1,3-pentadiene, 2,3-dimethylbutadiene and the like Conjugated diene compounds; aromatic vinyl compounds such as styrene; nonconjugated olefin compounds such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene; and the like. These may be used individually by 1 type and may use 2 or more types together.
Among these, 1,3-butadiene and styrene are preferable in terms of ease of molecular weight control.

(1,4-cis bond amount)
There is no restriction | limiting in particular as the amount of 1, 4- cis bonds of the isoprene origin part in an isoprene copolymer, Although it can select suitably according to the objective, 95% or more is more preferable, and 98% or more is especially preferable.
When the 1,4-cis bond amount is 95% or more, sufficient stretched crystallinity can be expressed.
On the other hand, when the 1,4-cis bond amount is in the more preferable range or in the particularly preferable range, it is advantageous in terms of improvement in durability due to stretched crystallinity.
The amount of 1,4-cis bond (the amount of 1,4-trans bond and the amount of 3,4-vinyl bond described later) is the amount in the isoprene-derived portion, and is a ratio to the entire isoprene copolymer. is not.

(1,4-trans bond amount)
The amount of 1,4-trans bond in the isoprene copolymer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10% or less, and more preferably 5% or less.
When the 1,4-trans bond amount is 5% or less, sufficient stretched crystallinity can be expressed.
On the other hand, when the 1,4-trans bond amount is in the more preferable range, it is advantageous in terms of improvement in durability due to stretched crystallinity.

(3,4-vinyl bond amount)
The amount of 3,4-vinyl bond in the isoprene-derived portion of isoprene in the isoprene copolymer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5% or less, particularly preferably 2% or less. .
When the 3,4-vinyl bond amount is 5% or less, sufficient stretch crystallinity can be expressed.
On the other hand, if the 3,4-vinyl bond amount is within the more preferable range or the particularly preferable range, it is advantageous in terms of improvement in durability due to stretched crystallinity.

(Content of isoprene-derived portion in isoprene copolymer)
There is no restriction | limiting in particular as content of the isoprene origin part in an isoprene copolymer, Although it can select suitably according to the objective, 5 mol%-95 mol% are preferable.
If the content of the isoprene-derived portion in the isoprene copolymer is 5 mol% or more, it is preferable because the characteristics of isoprene can be sufficiently exhibited. If it is 95 mol% or less, the characteristics of copolymer components other than isoprene are sufficiently exhibited Since it can be exhibited, it is preferable.

(Chain structure)
Examples of the chain structure of the polyisoprene polymer include a block copolymer, a random copolymer, a taper copolymer, and an alternating copolymer. In the present invention, the block copolymer is preferable.

--Block copolymer--
The structure of the block copolymer is (AB) _x , A- (BA) _x and B- (AB) _x (where A is a block portion composed of monomer units of isoprene. And B is a block portion composed of monomer units of a compound other than isoprene, and x is an integer of 1 or more. In addition, the block copolymer provided with two or more structures of (AB) or (BA) is called a multi-block copolymer.

-Method for producing isoprene copolymer-
Next, the manufacturing method which can manufacture an isoprene copolymer is demonstrated in detail. However, the manufacturing method described in detail below is merely an example. The isoprene copolymer can polymerize isoprene and a compound other than isoprene as a monomer in the presence of the polymerization catalyst composition.
The method for producing an isoprene copolymer of the present invention includes at least a polymerization step, and further includes a coupling step, a washing step, and other steps appropriately selected as necessary.

-Polymerization process-
The polymerization step is a step of copolymerizing isoprene as a monomer and a compound other than isoprene.

  In the polymerization step, it is a monomer in the same manner as in the method for producing a polymer using a normal coordination ion polymerization catalyst, except that the first, second, or third polymerization catalyst composition described above is used. Isoprene and compounds other than isoprene can be copolymerized. In the present invention, the polymerization catalyst composition used is as described above.

  As the catalyst in the polymerization step, the above-described first, second, or third polymerization catalyst composition can be used.

As a polymerization method, any method 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. Moreover, when using a solvent for a polymerization reaction, the solvent used should just be inactive in a polymerization reaction, For example, toluene, cyclohexane, normal hexane, mixtures thereof etc. are mentioned.
When the polymerization catalyst composition is used, for example, (1) in the polymerization reaction system containing isoprene and a compound other than isoprene as monomers, the components of the polymerization catalyst composition are separately provided, A polymerization catalyst composition may be used in the reaction system, or (2) a polymerization catalyst composition prepared in advance may be provided in the polymerization reaction system. Moreover, (2) includes providing a metallocene complex (active species) activated by a cocatalyst.

  In the polymerization step, the polymerization may be stopped using a polymerization terminator such as methanol, ethanol, or isopropanol.

  In the polymerization step, the polymerization reaction of isoprene and compounds other than isoprene is preferably performed in an atmosphere of an inert gas, preferably nitrogen gas or argon gas. The polymerization temperature of the polymerization reaction is not particularly limited, but is preferably in the range of −100 ° C. to 200 ° C., for example, and may be about room temperature. If the polymerization temperature is raised, the cis-1,4 selectivity of the polymerization reaction may be lowered. In addition, the pressure of the polymerization reaction is preferably in the range of 0.1 MPa to 10.0 MPa in order to sufficiently incorporate isoprene and compounds other than isoprene into the polymerization reaction system. Also, the reaction time of the polymerization reaction is not particularly limited and is preferably in the range of, for example, 1 second to 10 days, but can be appropriately selected depending on conditions such as the type of monomer to be polymerized, the type of catalyst, and the polymerization temperature. .

--Coupling process--
The coupling step is a step in which at least a part (for example, terminals) of the polymer chains of the isoprene copolymer obtained in the polymerization step are subjected to a coupling reaction.
In the coupling step, it is preferable to perform a coupling reaction (a reaction for modifying the terminal of the polymer chain) when the polymerization reaction reaches 100%.
There is no restriction | limiting in particular as a coupling agent used for a coupling reaction, According to the objective, it can select suitably, For example, (i) Tin content, such as bis (1-octadecyl maleate) dioctyl tin (IV) Compounds, (ii) isocyanate compounds such as 4,4′-diphenylmethane diisocyanate, (iii) alkoxysilane compounds such as glycidylpropyltrimethoxysilane, and the like. These may be used individually by 1 type and may use 2 or more types together.

Among these, bis (-1-octadecyl maleate) dioctyltin (IV) is preferable in terms of reaction efficiency and low gel formation.
In addition, by performing a coupling reaction, it is possible to achieve a high molecular weight by bonding polymer chains together, and also to prevent degradation other than hydrolysis and to reduce the number average molecular weight (Mn). Can be suppressed.

There is no restriction | limiting in particular as reaction temperature in a coupling reaction, Although it can select suitably according to the objective, 10 to 100 degreeC is preferable and 20 to 80 degreeC is more preferable.
When the reaction temperature is 10 ° C. or higher, the reaction rate can be prevented from significantly decreasing, and when the reaction temperature is 100 ° C. or lower, the polymer can be prevented from gelling.
There is no restriction | limiting in particular as reaction time in a coupling reaction, Although it can select suitably according to the objective, 10 minutes-1 hour are preferable.
When the reaction time is 10 minutes or longer, the reaction can be sufficiently carried out, and when it is 1 hour or shorter, the polymer can be prevented from gelling.

-Cleaning process-
The washing step is a step of washing the isoprene copolymer obtained in the polymerization step. In addition, there is no restriction | limiting in particular as a medium used for washing | cleaning, According to the objective, it can select suitably, For example, methanol, ethanol, isopropanol, etc. are mentioned.

[Other rubber components]
The rubber component of the present invention includes the polyisoprene of the present invention, but may further include other rubber components as necessary.
The rubber component (other rubber) other than the polyisoprene of the present invention is not particularly limited and can be appropriately selected according to the purpose. For example, natural rubber (NR), butadiene rubber (BR), styrene butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber, ethylene-propylene rubber (EPM), ethylene-propylene-nonconjugated diene rubber (EPDM), polysulfide rubber, silicone rubber, fluorine rubber, urethane rubber and the like. . These may be used individually by 1 type and may use 2 or more types together.

The total amount of the polyisoprene of the present invention in all rubber components is preferably 20% by mass to 100% by mass with respect to the mass of all rubber components.
When the rubber component is blended with the polyisoprene of the present invention in the above range, a crosslinked rubber composition having increased stretch crystallinity and improved durability (cracking resistance and abrasion resistance) can be obtained.
The total amount of the polyisoprene of the present invention in all rubber components is more preferably 40% by mass to 100% by mass.

<Rubber composition>
The rubber composition of the present invention is formed by blending the rubber component of the present invention.
The rubber composition of the present invention may contain additives such as a filler and a crosslinking agent as long as the effects of the present invention are not impaired.

<Filler>
The filler is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include carbon black and inorganic filler, and at least one selected from carbon black and inorganic filler preferable. Here, it is more preferable that the rubber composition contains carbon black. In addition, a filler is mix | blended with a rubber composition in order to improve reinforcement property.

There is no restriction | limiting in particular as a compounding quantity (content) of a filler, Although it can select suitably according to the objective, 10 mass parts-75 mass parts are preferable with respect to 100 mass parts of all the rubber components, and 20 masses. Part to 75 parts by weight is more preferable, and 30 parts to 60 parts by weight is particularly preferable.
When the blending amount of the filler is 10 parts by mass or more with respect to 100 parts by mass of the total rubber component, the effect of adding the filler is seen, and when it is 100 parts by mass or less, the filler is mixed into the rubber component. And the performance as a rubber composition can be improved.

  On the other hand, if the blending amount of the filler is within the more preferable range or the particularly preferable range, it is advantageous in terms of the balance between processability, low loss and durability.

〔Carbon black〕
There is no restriction | limiting in particular as carbon black, According to the objective, it can select suitably, For example, FEF, GPF, SRF, HAF, N339, IISAF, ISAF, SAF etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

The nitrogen adsorption specific surface area (measured according to N ₂ SA, JIS K 6217-2: 2001) of carbon black is not particularly limited and may be appropriately selected depending on the intended purpose, but is 20 m ² / g. ~150m ² / g are preferred, 35m ² / g~145m ² / g is more preferable.
When the nitrogen adsorption specific surface area (N ₂ SA) of carbon black is 20 m ² / g or more, the durability of the obtained rubber can be prevented from deteriorating, and sufficient crack growth resistance can be obtained. When it is 150 m ² / g or less, low loss can be improved and workability can be improved.

There is no restriction | limiting in particular as content of carbon black with respect to 100 mass parts of all the rubber components, Although it can select suitably according to the objective, 10 mass parts-100 mass parts are preferable, and 10 mass parts-70 mass parts are. More preferred is 20 to 60 parts by mass.
When the content of carbon black is 10 parts by mass or more, it is possible to prevent deterioration of the fracture resistance due to insufficient reinforcement, and when it is 100 parts by mass or less, workability and low loss are obtained. Deterioration can be prevented.

  On the other hand, when the content of carbon black is within the more preferable range or the particularly preferable range, it is advantageous in terms of balance of performance.

[Inorganic filler]
The inorganic filler is not particularly limited and may be appropriately selected depending on the intended purpose. For example, silica, aluminum hydroxide, clay, alumina, talc, mica, kaolin, glass balloon, glass beads, calcium carbonate, carbonate Examples thereof include magnesium, magnesium hydroxide, calcium carbonate, magnesium oxide, titanium oxide, potassium titanate, and barium sulfate. These may be used individually by 1 type and may use 2 or more types together.
In addition, when using an inorganic filler, you may use a silane coupling agent suitably.

<Crosslinking agent>
The crosslinking agent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a sulfur-based crosslinking agent, an organic peroxide-based crosslinking agent, an inorganic crosslinking agent, a polyamine crosslinking agent, a resin crosslinking agent, and a sulfur compound. Examples of such a crosslinking agent include oxime-nitrosamine crosslinking agent sulfur and the like. Among these, a sulfur crosslinking agent is more preferable as a rubber composition for tires.

There is no restriction | limiting in particular as content of a crosslinking agent, Although it can select suitably according to the objective, 0.1 mass part-20 mass parts are preferable with respect to 100 mass parts of rubber components.
When the content of the cross-linking agent is 0.1 parts by mass or more, the cross-linking can proceed and is 20 parts by mass or less to prevent the cross-linking from proceeding during kneading with some cross-linking agents. Or the physical properties of the vulcanizate can be prevented from being impaired.

<Other ingredients>
In addition, it is also possible to use a vulcanization accelerator in combination, and examples of the vulcanization accelerator include guanidine, aldehyde-amine, aldehyde-ammonia, thiazole, sulfenamide, thiourea, thiuram, Dithiocarbamate and xanthate compounds can be used.
If necessary, softeners, vulcanization aids, colorants, flame retardants, lubricants, foaming agents, plasticizers, processing aids, antioxidants, anti-aging agents, scorch inhibitors, UV inhibitors, antistatic agents Known agents such as a colorant, an anti-coloring agent, and other compounding agents can be used depending on the purpose of use.

<< Crosslinked rubber composition >>
The crosslinked rubber composition of the present invention is not particularly limited as long as it is obtained by crosslinking the rubber composition of the present invention, and can be appropriately selected according to the purpose. A crosslinked rubber composition using sulfur as a crosslinking agent may be referred to as vulcanized rubber.
The crosslinking conditions of the rubber composition of the present invention are not particularly limited and may be appropriately selected depending on the intended purpose. However, a temperature of 120 ° C. to 200 ° C. and a heating time of 1 minute to 900 minutes are preferable.

"tire"
The tire of the present invention comprises the rubber composition of the present invention. More specifically, a crosslinked rubber composition (crosslinked rubber composition of the present invention) formed by crosslinking the rubber composition of the present invention is disposed. Being done.
The tire of the present invention is not particularly limited as long as the rubber composition of the present invention is used, and can be appropriately selected according to the purpose.
The application site in the tire of the rubber composition of the present invention is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include treads, base treads, sidewalls, side reinforcing rubbers, and bead fillers. .

Among these, it is advantageous in terms of durability that the application site of the rubber composition of the present invention is a tread. That is, the tire of the present invention is preferably formed by blending the rubber composition of the present invention with a tread member.
As a method for producing a tire, a conventional method can be used. For example, members used in normal tire production such as a carcass layer, a belt layer, and a tread layer made of unvulcanized rubber and / or cord are sequentially laminated on a tire molding drum, and the drum is removed to obtain a green tire. Then, a desired tire (for example, a pneumatic tire) can be manufactured by heating and vulcanizing the green tire according to a conventional method.

(Applications other than tires)
Besides the tire application, the crosslinked rubber composition of the present invention can be used for vibration-proof rubber, seismic isolation rubber, belt (conveyor belt), rubber crawler, various hoses and the like.

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

<< Examples 1 to 6, Comparative Examples 1 to 3 and Reference Example 1 >>
[Production Example 1: Method for producing polymer A]
800 g of hexane solvent (12% by mass) in which isoprene was dissolved was introduced into a sufficiently dried 2 L stainless steel reactor. On the other hand, in a glove box under a nitrogen atmosphere, in a glass container, 14.5 μmol of trisbistrimethylsilylamidogadolinium Gd [N (SiMe ₃ ) ₂ ] ₃ , 5 ml of toluene, 0.44 mmol of diisobutylaluminum hydride, bis (2-diphenylphosphine) Finophenyl) amine (16 μmol) and triphenylcarbonium tetrakis (pentafluorophenyl) borate (Ph3CB (C6F5) 4) (16 μmol) were charged to prepare a catalyst solution. Thereafter, the catalyst solution was taken out from the glove box, added to the isoprene monomer solution, and polymerized at 25 ° C. for 10 hours. After the polymerization, 1 ml of 2,2′-methylene-bis (4-ethyl-6-t-butylphenol) (NS-5) 5% by mass isopropanol solution was added to stop the reaction, and the copolymer was separated with a large amount of methanol. The polymer A was obtained by vacuum drying at 60 ° C.

[Production Example 2: Method for producing polymer B]
In Production Example 1, a polymer B was obtained in the same manner as in Production Example 1 except that diisobutylaluminum hydride was 0.48 mmol and the polymerization temperature was 50 ° C. for 4 hours.

[Production Example 3: Production Method of Polymer C]
In Production Example 1, except that the hexane solvent was changed to a toluene solvent, trisbistrimethylsilylamid gadolinium Gd [N (SiMe ₃ ) ₂ ] ₃ 10.0 μmol diisobutylaluminum hydride 1.02 mmol, and the polymerization temperature was 50 ° C. for 4 hours. Produced polymer C in the same manner as in Production Example 1.

[Production Example 4: Production Method of Polymer D]
In Production Example 1, a polymer D was obtained in the same manner as in Production Example 1, except that 3.5 mmol of diisobutylaluminum hydride and the polymerization temperature were set to 80 ° C. for 1 hour.

[Production Example 5: Production method of polymer E]
800 g of toluene solvent (12% by mass) in which isoprene was dissolved was introduced into a sufficiently dry 2 L stainless steel reactor. On the other hand, in a glove box under a nitrogen atmosphere, 59 μmol of trisbistrimethylsilylamid gadolinium Gd [N (SiMe ₃ ) ₂ ] ₃ , 40 ml of toluene, 3.6 mmol of diisobutylaluminum hydride, bis (2-diphenylphosphinophenyl) ) 62 μmol of amine and 62.4 μmol of triphenylcarbonium tetrakis (pentafluorophenyl) borate (Ph3CB (C6F5) 4) were used as a catalyst solution. Thereafter, the catalyst solution was taken out from the glove box, added to the isoprene monomer solution, and polymerized at 25 ° C. for 2 hours. Thereafter, 21.4 mmol of 3-glycidyloxypropylmethyldimethoxysilane was added, and a modification reaction was performed at 25 ° C. for 10 minutes. After the modification reaction, 2 ml of water and 2.1 mmol of dibutyltin diacetate were further added, and a coupling reaction was performed at 25 ° C. for 0.5 hour. After the coupling reaction, 1 ml of 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol) (NS-5) 5% by mass isopropanol solution was added to stop the reaction, and a copolymer with a large amount of methanol was added. Was separated and vacuum dried at 60 ° C. to obtain a polymer E.

  For polymers A to E prepared as described above, weight average molecular weight (Mw), molecular weight distribution (Mw / Mn), microstructure (1,4-cis bond amount, and 3,4-vinyl bond amount), The macrogel fraction was measured and evaluated by the following method. The results are shown in Table 1.

<Analytical Method of Polymers A to E>
(1) Microstructure (1,4-cis bond amount and 3,4-vinyl bond amount)
Peaks obtained by ¹ H-NMR and ¹³ C-NMR [ ¹ H-NMR: δ 4.6-4.8 (3,4-vinyl unit = CH ₂ ), 5.0-5.2 (1, 4-unit -CH =), 13C-NMR: [δ 23.4 (1,4-cis unit), 15.9 (1,4-trans unit), 18.6 (3,4-unit)] Each was calculated from the integration ratio. The number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) were determined by polystyrene using polystyrene as a standard substance.

(2) Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn)
It was measured by gel permeation chromatography [GPC: manufactured by Tosoh Corporation, HLC-8020] using a refractometer as a detector, and was shown in terms of polystyrene using monodisperse polystyrene as a standard. Two columns, Shodex (registered trademark) KF807F [manufactured by Showa Denko KK], were connected in series, the eluent was tetrahydrofuran, and the measurement temperature was 40 ° C.

(3) Macrogel fraction A 100 mesh (0.15 mm) stainless steel wire mesh cage containing 0.4 g of sample polymer was immersed in a sample bottle containing 100 cc of tetrahydrofuran and allowed to stand for 48 hours. Thereafter, the mesh wrinkle was taken out, the sample remaining in the wrinkle was dried, the weight was measured, and the weight was divided by the initial sample weight to calculate the macrogel fraction (unit:%).

<Preparation of rubber component and measurement of molecular weight distribution>
[Preparation of rubber components 1-6 and rubber components 101-103]
Into a 2 L stainless steel reactor, 60 g of the polymer was charged according to the formulation shown in Table 2, 1 L in hexane was added thereto, and the mixture was dissolved at 30 ° C. for 48 hours. After mixing, 10 mL of a 10% by weight methanol solution of BHT [2,6-bis (t-butyl) -4-methylphenol] was further separated with a large amount of methanol / hydrochloric acid mixed solvent, and the polymer was vacuumed at 60 ° C. The rubber components having the compositions shown in Table 2 were obtained by drying. Moreover, about the obtained rubber component, the molecular weight by gel permeation chromatography (GPC) measurement is measured, and the component amount whose weight average molecular weight (Mw) is 6 million or more and the component which is 800,000 or less from the area of the obtained chromatogram. The amount (mass%) and the weight average molecular weight (Mw) of 8 million or more component amounts and 500,000 or less component amounts (mass percent) were determined.

  Further, natural rubber was prepared as the rubber component 201 of Reference Example 1.

  In addition, the rubber component 6 (polyisoprene homopolymer having a branched structure) of Example 6 was 8% by mass of 8 million or more components and 22% by mass of 500,000 or less components in GPC measurement.

(Preparation of rubber composition)
Using rubber components 1-6, rubber components 101-103, and rubber component 201 as rubber components, rubber compositions 1-6, 101-103, and 201 were prepared according to the formulation shown in Table 3.

The components * 1 to * 3 in Table 3 are as follows.
* 1: N- (1,3-dimethylbutyl) -N′-p-phenylenediamine, manufactured by Ouchi Shinsei Chemical Co., Ltd., knock rack 6C
* 2: N-cyclohexyl-2-benzothiazolylsulfenamide, manufactured by Ouchi Shinsei Chemical Co., Ltd., Noxeller CZ-G
* 3: Dibenzothiazyl disulfide, manufactured by Ouchi Shinsei Chemical Co., Ltd., Noxeller DM-P

  About the obtained rubber compositions 1-6, 101-103, and 201, according to the following method, (1) Workability (Mooney viscosity) was measured. Moreover, according to the following method with respect to the vulcanized rubber obtained by heating rubber composition 1-6, 101-103, and 201 for 30 minutes at 145 degreeC, (2) Crack resistance and (3) Abrasion resistance Was measured. Table 4 shows the measurement results.

(1) Workability (Mooney viscosity)
As an index of processability of the rubber composition, Mooney viscosity (compound Mooney) was measured according to JIS K6300-1 (unit: [ML _{1 + 4} , 130 ° C.]). The results are shown in Table 4.

(2) Fatigue resistance (index)
A 0.5 mm crack was made at the center of a JIS No. 3 test piece, bending fatigue and extension fatigue were repeatedly given at a constant strain of 0% to 100% at room temperature, and the number of times until the sample was cut was measured. The measurement result was displayed as an index with Comparative Example 1 as 100. A larger index value indicates better fatigue resistance (crack growth resistance). The results are shown in Table 4.

(3) Abrasion resistance (index)
The amount of wear was measured at a slip rate of 60% at room temperature using a Lambourn type wear tester, and displayed as an index with the reciprocal of Comparative Example 1 being 100. The higher the value, the better the wear resistance. The results are shown in Table 4.

<< Examples 7 to 9, Comparative Examples 4 to 5 and Reference Example 2 >>
As shown in Table 5, rubber compositions 7 to 7 having a blended formulation in which BR (manufactured by JSR Corporation, BR01) and the rubbers obtained in Examples 1, 4, 6, Comparative Examples 1, 3 and Reference Example 1 were mixed. 9, 104-105 and 202 were prepared.
The obtained rubber compositions 7 to 9, 104 to 105 and 202 were measured for (1) workability (Mooney viscosity) according to the above method. Moreover, according to said method with respect to the vulcanized rubber obtained by heating rubber compositions 7-9, 104-105, and 202 for 30 minutes at 145 degreeC, (2) Crack resistance and (3) Abrasion resistance Sex was measured. Table 5 shows the measurement results.

  Table 4 and Table 5 show that the rubber component contains a polyisoprene polymer having a weight average molecular weight of 6,000,000 or more and a polyisoprene polymer having a weight average molecular weight of 800,000 or less. It can be seen that a rubber composition having good durability and durability (cracking resistance and abrasion resistance) comparable to natural rubber (Reference Examples 1 and 2) can be obtained.

  The rubber component of the present invention and the rubber composition containing the rubber component can be suitably used for, for example, a tire member.

Claims (13)

The amount of components having a polystyrene equivalent weight average molecular weight of 6,000,000 or more by gel permeation chromatography is 10% by mass to 40% by mass, and the polystyrene equivalent weight average molecular weight by gel permeation chromatography is A rubber component containing polyisoprene having a component amount of 800,000 or less of 5% by mass to 30% by mass. The polyisoprene is a component having a polystyrene equivalent weight average molecular weight of 800,000 as measured by gel permeation chromatography and a component having a polystyrene equivalent weight average molecular weight of less than 6,000,000 as measured by gel permeation chromatography. The rubber component according to claim 1, comprising 30% by mass to 85% by mass. The rubber component according to claim 1 or 2 , wherein the polyisoprene is a mixture of polyisoprene polymers or an isoprene homopolymer having a branched structure. The polyisoprene is composed of 10 mass% to 40 mass% of a polyisoprene polymer having a weight average molecular weight of 6,000,000 or more, and 5 mass% to 30 mass% of a polyisoprene polymer having a weight average molecular weight of 800,000 or less. The rubber component according to any one of claims 1 to 3, wherein the rubber component is a mixture containing 1%. The polyisoprene is composed of 10 mass% to 40 mass% of a polyisoprene polymer having a weight average molecular weight of 6,000,000 or more, and 5 mass% to 30 mass% of a polyisoprene polymer having a weight average molecular weight of 800,000 or less. The rubber component according to any one of claims 1 to 3, comprising:% as a polymerization component. The isoprene homopolymer having the branched structure contains 5% by mass to 30% by mass of an isoprene homopolymer having a weight average molecular weight of 8,000,000 or more in terms of polystyrene as measured by gel permeation chromatography, and rubber component according to gel permeation chromatography claim 3 containing 3 wt% to 30 wt% of the weight average molecular weight of 500,000 or less isoprene homopolymer in terms of polystyrene as polymer component by measuring. The rubber component according to claim 3 , wherein the amount of 1,4-cis bonds in the polyisoprene polymer is 90% or more. The rubber component according to claim 3 or 6 , wherein the polyisoprene homopolymer having a branched structure has a 1,4-cis bond content of 90% or more. The rubber component according to any one of claims 1 to 8 , wherein a total blending amount of the polyisoprene is 20% by mass to 100% by mass. Rubber composition obtained by compounding a rubber component according to any one of claims 1-9. The rubber composition according to claim 10 , further comprising a filler, wherein the amount of the filler is 10 to 75 parts by mass with respect to 100 parts by mass of all rubber components. A tire using the rubber composition according to claim 10 or 11 . A tire using the rubber composition according to claim 10 or 11 for a tread member.