JP2011111510A - Runflat tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a runflat tire with excellent runflat durability. <P>SOLUTION: A rubber composition (B) containing a rubber component (A) containing an aromatic vinyl compound-conjugated diene compound copolymer (A1) is applied to any of rubber members. The aromatic vinyl compound-conjugated diene compound copolymer (A1) having a cis-1,4 bond content of 80% or more in the conjugated diene compound moiety is obtained by performing addition polymerization of the aromatic vinyl compound and the conjugated diene compound in the presence of a polymerization catalyst composition containing at least one specific metallocene complex, such as a metallocene complex represented by general formula (I), wherein M is lanthanoid, scandium, or yttrium; Cp<SP>R</SP>s are each independently a non-substituted or substituted indenyl; R<SP>a</SP>to R<SP>f</SP>are each independently a 1-3C alkyl group; L is a neutral Lewis base; and w is an integer of 0-3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a run-flat tire using a rubber composition (B) containing a rubber component (A) containing an aromatic vinyl compound-conjugated diene compound copolymer (A1) for any rubber member, and more particularly to a side portion. It is related with the run flat tire using the rubber composition (B) which can provide the run flat durability which was excellent in the tire by using for this reinforcing rubber and / or bead filler.

  In recent years, there is an increasing demand for run-flat tires that can travel a certain distance even when the tire internal pressure drops abnormally or punctures. The run-flat tire has already been developed a lot in summer tires and the like for traveling on a normal paved road surface. As one of such run-flat tires, a reinforcing rubber layer having a crescent cross section made of a relatively hard rubber is disposed on the inner surface of the side wall of the carcass so that when the internal pressure is abnormally lowered or punctured, There is a so-called side reinforcement type run flat tire that supports a load by making the sidewall portion difficult to deform.

However, conventional run-flat tires using synthetic rubber have a problem that durability against repeated input (fatigue resistance, heat fatigue resistance) is not sufficient, and the run-flat durability is not always sufficient.
On the other hand, although the device of using a specific vulcanization accelerator (for example, refer patent document 1) was made | formed, there existed a problem that the run flat durability was not necessarily enough.

  On the other hand, there is an attempt to improve physical properties by controlling the structure of the rubber itself. As an example, in order to control the stereoregularity of the conjugated diene compound part, for example, the content of the cis-1,4 structure, a metal catalyst comprising a ligand and a metal atom is used, and an aromatic vinyl compound-conjugated diene is used. A technique for generating a compound copolymer is known (see, for example, Patent Document 2 to Patent Document 4). However, because the aromatic vinyl compound-conjugated diene compound copolymer obtained by the method includes problems such as blocking or lowering the molecular weight of the aromatic vinyl compound portion, the aromatic vinyl compound- Even when the conjugated diene compound copolymer is used, there is a problem that durability against repeated input (fatigue resistance, heat fatigue resistance) is not sufficient, and the run-flat durability is not always sufficient.

Japanese Patent Laid-Open No. 2004-256792 Japanese Patent No. 3207502 JP 2006-137897 A Japanese Patent No. 3738315

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a run flat tire that solves the above-described problems of the prior art and has excellent run flat durability.

  As a result of intensive studies to achieve the above object, the present inventor has carried out addition polymerization of an aromatic vinyl compound and a conjugated diene compound in the presence of a polymerization catalyst composition containing a specific metallocene complex, thereby producing a conjugated diene compound moiety. A copolymer (A1) having a cis-1,4 bond content of 80% or more is obtained, and a rubber composition (B) containing a rubber component (A) containing the copolymer (A1) is applied to a tire. Thus, compared to a conventional run flat tire having the same structure, the crack growth resistance and run flat durability can be greatly improved without increasing the mass of the reinforcing rubber layer, and the stress at 100% elongation ( Since M100) does not increase, the rigidity in the tire radial direction does not increase, and it has been found that the riding comfort does not change during normal running when the tire is filled with internal pressure, and the present invention has been completed.

（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)：

（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)：

（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な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の存在下、芳香族ビニル化合物及び共役ジエン化合物を付加重合して得られた、共役ジエン化合物部分のシス-１,４結合量が８０％以上の芳香族ビニル化合物−共役ジエン化合物共重合体（Ａ１）を含むゴム成分（Ａ）を含むゴム組成物（Ｂ）をゴム部材のいずれかに適用したことを特徴とする。 That is, the run flat tire of the present invention has the 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. And L represents a neutral Lewis base, and w represents an integer of 0 to 3), and the following general formula (II):

(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, w represents an integer of 0 to 3, and the following general formula (III ):

(In the formula, M represents a lanthanoid element, scandium or yttrium, Cp ^{R ′} represents unsubstituted or substituted cyclopentadienyl, indenyl or fluorenyl, and X represents a hydrogen atom, a halogen atom, an alkoxide group or a thiolate group. represents an amide group, a silyl group or a hydrocarbon group having a carbon number of 1 to 20, L is a neutral Lewis base, w is, an integer of 0 to 3, [B] ^- is a non-coordinating Obtained by addition polymerization of an aromatic vinyl compound and a conjugated diene compound in the presence of a polymerization catalyst composition containing at least one complex selected from the group consisting of a half metallocene cation complex represented by A rubber containing a rubber component (A) containing an aromatic vinyl compound-conjugated diene compound copolymer (A1) having a cis-1,4 bond amount of 80% or more in the conjugated diene compound portion Narubutsu the (B) characterized by being applied to one of the rubber members.

  Here, the metallocene complex is a complex compound in which one or more cyclopentadienyl or a derivative thereof is bonded to a central metal, and in particular, one cyclopentadienyl or a derivative thereof bonded to the central metal. A certain metallocene complex may be called a half metallocene complex.

  In the rubber composition (B) used for the run-flat tire of the present invention, the vinyl bond content of the conjugated diene compound portion of the copolymer (A1) is preferably 10% or less.

  In the rubber composition (B) used for the run-flat tire of the present invention, the block amount in the NMR measurement of the repeating unit of the aromatic vinyl compound portion of the copolymer (A1) is 10% of the total aromatic vinyl compound portion. The following is preferable.

  In the rubber composition (B) used for the run flat tire of the present invention, the copolymer (A1) preferably has a melting point (Tm) in DSC measurement.

  In another preferred embodiment of the rubber composition (B) used in the run flat tire of the present invention, the copolymer (A1) is a styrene-butadiene copolymer.

  Furthermore, the run-flat tire of the present invention is characterized in that the rubber composition (B) is used for any rubber member of the run-flat tire, and is particularly preferably used for a side portion reinforcing rubber and / or bead filler. .

  ADVANTAGE OF THE INVENTION According to this invention, the run flat tire excellent in run flat durability can be provided by using the rubber composition (B) containing the rubber component (A) containing a specific copolymer (A1). .

It is a mimetic diagram showing the section of one embodiment of the run flat tire of the present invention.

（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)：

（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)：

（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な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の存在下、芳香族ビニル化合物及び共役ジエン化合物を付加重合して得られた、共役ジエン化合物部分のシス-１,４結合量が８０％以上の芳香族ビニル化合物−共役ジエン化合物共重合体（Ａ１）を含むゴム成分（Ａ）を含むゴム組成物（Ｂ）をゴム部材のいずれかに適用したことを特徴とする。 The present invention is described in detail below.
The run flat tire of the present invention has the 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. And L represents a neutral Lewis base, and w represents an integer of 0 to 3), and the following general formula (II):

(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, w represents an integer of 0 to 3, and the following general formula (III ):

(In the formula, M represents a lanthanoid element, scandium or yttrium, Cp ^{R ′} represents unsubstituted or substituted cyclopentadienyl, indenyl or fluorenyl, and X represents a hydrogen atom, a halogen atom, an alkoxide group or a thiolate group. represents an amide group, a silyl group or a hydrocarbon group having a carbon number of 1 to 20, L is a neutral Lewis base, w is, an integer of 0 to 3, [B] ^- is a non-coordinating Obtained by addition polymerization of an aromatic vinyl compound and a conjugated diene compound in the presence of a polymerization catalyst composition containing at least one complex selected from the group consisting of a half metallocene cation complex represented by A rubber containing a rubber component (A) containing an aromatic vinyl compound-conjugated diene compound copolymer (A1) having a cis-1,4 bond amount of 80% or more in the conjugated diene compound portion Narubutsu the (B) characterized by being applied to one of the rubber members.

[Rubber component (A)]
The rubber component (A) needs to contain the copolymer (A1), and preferably contains 50% by mass or more. When the rubber component (A) includes a rubber component (A2) other than the copolymer (A1), examples of the other rubber component (A2) include natural rubber (NR) and polyisoprene. Rubber (IR), polybutadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), butyl rubber (IIR), styrene-isoprene rubber, styrene-isoprene-butadiene Rubber, butadiene-isoprene rubber, silicone rubber, fluoroelastomer, ethylene / acrylic rubber, ethylene propylene rubber (EPR), ethylene / propylene / diene monomer (EPDM) rubber, hydrogenated nitrile rubber, etc. Combined rubber, natural rubber, polybutadiene rubber and polyisopropylene Ngomu is preferable. In addition, these other rubber components (A2) may be used alone or in a blend of two or more.

[Aromatic vinyl compound-conjugated diene compound copolymer (A1)]
The copolymer (A1) is selected from the group consisting of the metallocene complexes represented by the general formula (I) and the general formula (II) and the half metallocene cation complex represented by the general formula (III). An aromatic compound having a cis-1,4 bond content of 80% or more in a conjugated diene compound portion obtained by addition polymerization of an aromatic vinyl compound and a conjugated diene compound in the presence of a polymerization catalyst composition containing at least one kind of complex. Group vinyl compound-conjugated diene compound copolymer.

The copolymer (A1) has a very high amount of cis-1,4 bonds in the conjugated diene compound portion, and a rubber composition (B) using the copolymer (A1) as a rubber component (A) is: A rubber composition using a conventional aromatic vinyl compound-conjugated diene compound copolymer obtained by anionic polymerization and a conventional aromatic vinyl compound-conjugated diene compound copolymer have a cis-1,4 bond amount. The crack growth resistance and run flat durability can be improved as compared with a rubber composition used by blending with a homopolymer of a high conjugated diene compound. The reason for this is not necessarily clear, but the crystallinity derived from the amount of cis-1,4 bonds in the conjugated diene compound part causes a decrease in hysteresis loss (tan δ) due to low glass transition temperature (Tg) (low heat generation) This is thought to be due to the effect of improving the run-flat durability associated with), the crack growth resistance accompanying the improvement of the fracture strength due to the improvement of elongation crystallinity, and the effect of improving the run-flat durability. here,
The amount of cis-1,4 bonds in the conjugated diene compound portion needs to be 80% or more, and preferably 90% or more. When the amount of cis-1,4 bonds in the conjugated diene compound portion is less than 80%, the cis chain is insufficient, so the melting point (Tm) is not measured, and crack growth resistance, run flat durability, and wear resistance performance Will decline. The amount of cis-1,4 bonds in the conjugated diene compound portion can be determined from the integration ratio of ¹ H-NMR spectrum and ¹³ C-NMR spectrum, and the specific method is disclosed in JP-A-2004-27179. It is disclosed.

In the copolymer (A1), the vinyl bond content of the conjugated diene compound portion is preferably 10% or less, and more preferably 5% or less. When the vinyl bond amount of the conjugated diene compound portion exceeds 10%, the cis-1,4 bond amount is lowered, and the effect of improving crack growth resistance and run flat durability cannot be obtained sufficiently. The vinyl bond amount in the conjugated diene compound portion can be determined from the integral ratio of the ¹ H-NMR spectrum and the ¹³ C-NMR spectrum as in the above-described cis-1,4 bond amount.

In the copolymer (A1), the amount of blocks in the NMR measurement of the repeating unit of the aromatic vinyl compound portion is preferably 10% or less of the total aromatic vinyl compound portion, and preferably 7% or less. Is more preferred, with 0% being particularly preferred. The copolymer (A1) obtained by using the polymerization catalyst composition tends to polymerize the aromatic vinyl compound at random, and can suppress blocking of the aromatic vinyl compound. Here, the term “random” means that the amount of block in the NMR measurement of the repeating unit of the aromatic vinyl compound portion (hereinafter sometimes referred to as “block aromatic vinyl compound content”) is 10% or less of the total aromatic vinyl compound portion. The block refers to an aromatic vinyl compound portion having an aromatic vinyl compound-aromatic vinyl compound bond. When the content of the block aromatic vinyl compound exceeds 10%, the behavior of the aromatic vinyl compound as a homopolymer appears, the glass transition point (Tg) rises, and the crack growth resistance and run flat durability are improved. May decrease. In addition, a block aromatic vinyl compound content rate can be calculated | required from the integral ratio of a < ¹ > H-NMR spectrum.

  Furthermore, the copolymer (A1) exhibits a melting point (Tm) in DSC measurement (differential scanning calorimetry). Here, the melting point (Tm) in DSC measurement refers to the melting point of a static crystal derived from a chain of conjugated diene compound portions.

  The copolymer (A1) is not particularly limited except that a polymerization catalyst composition described in detail later is used. For example, in the same manner as the production method of an addition polymer using a normal coordination ion polymerization catalyst, It can be obtained by copolymerizing a mixture of a monomeric aromatic vinyl compound and a conjugated diene compound. 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. When a solvent is used for the polymerization reaction, the solvent used may be inactive in the polymerization reaction, and the amount of the solvent used is arbitrary, but the concentration of the complex contained in the polymerization catalyst composition is 0.1 to 0.0001 mol. The amount is preferably / l. Here, examples of the aromatic vinyl compound include styrene, p-methylstyrene, m-methylstyrene, p-tert-butylstyrene, α-methylstyrene, chloromethylstyrene, vinyltoluene and the like. Among these, styrene Is preferred. On the other hand, examples of the conjugated diene compound include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, and among these, 1,3-butadiene is preferable. Therefore, a styrene-butadiene copolymer is particularly preferable as the copolymer (A1). Here, the run-flat tire preferably has an aromatic vinyl compound amount of 5% by mass to 20% by mass. If the amount of aromatic vinyl compound is too large, the heat build-up will deteriorate and the run-flat durability will decrease.On the other hand, if the amount of aromatic vinyl compound is too small, the fracture characteristics will decrease and the run-flat durability will decrease. is there.

[Polymerization catalyst composition used for synthesis of copolymer (A1)]
The polymerization catalyst composition used for the synthesis of the copolymer (A1) includes a metallocene complex represented by the general formulas (I) and (II) and a half metallocene cation complex represented by the general formula (III). It is necessary to include at least one kind of complex selected from the group consisting of, and it is preferable to further include other components such as a co-catalyst contained in the polymerization catalyst composition including a normal metallocene complex.

In the metallocene complexes represented by the above 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, 2-methylindenyl and the like. In addition, two Cp ^R in the general formula (I) and the formula (II) may be the same or different from each other.

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

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

In the general formula (III), Cp ^{R ′} having the 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 the 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. Moreover, it is preferable that R is respectively independently a hydrocarbyl group; metalloid group. The hydrocarbyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms. Specific examples of the hydrocarbyl group include a methyl group, an ethyl group, a phenyl group, and a benzyl group. On the other hand, examples of metalloid group metalloids include germyl Ge, stannyl Sn, and silyl Si, and the metalloid group preferably has a hydrocarbyl group, and the hydrocarbyl group that the metalloid group has is the same as the above hydrocarbyl group. is there. Specific examples of the metalloid group include a trimethylsilyl group.

  The central metal M in the general formula (I), formula (II) and formula (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 bistrialkylsilylamide ligand [—N (SiR ₃ ) ₂ ]. The alkyl groups R (R ^{a to} R ^f in the general formula (I)) contained in the bistrialkylsilylamide are each independently an alkyl group having 1 to 3 carbon atoms, and is preferably a methyl 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 and tert-butoxy group; phenoxy group and 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, Examples include aryloxide groups such as 2-isopropyl-6-neopentylphenoxy group, and among these, 2,6-di-tert-butylphenoxy group is preferable.

  In the general formula (III), the thiolate group represented by X includes a thiomethoxy group, a thioethoxy group, a thiopropoxy group, a thio n-butoxy group, a thioisobutoxy group, a thio sec-butoxy group, a thio tert-butoxy group and 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. Among these, 2,4,6-triisopropylthiophenoxy group is preferable.

  In the general formula (III), the amide group represented by X includes aliphatic amide groups such as dimethylamide group, diethylamide group and diisopropylamide group; phenylamide group, 2,6-di-tert-butylphenylamide group, 2 2,6-diisopropylphenylamide group, 2,6-dineopentylphenylamide group, 2-tert-butyl-6-isopropylphenylamide group, 2-tert-butyl-6-neopentylphenylamide group, 2-isopropyl- Arylamide groups such as 6-neopentylphenylamide group, 2,4,6-tert-butylphenylamide group; and bistrialkylsilylamide groups such as bistrimethylsilylamide group. Among these, bistrimethylsilylamide group is preferable.

  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. Specific examples of the hydrocarbon group having 1 to 20 carbon atoms represented by X include methyl group, 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 tetraphenylborate, 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 above general formulas (I) and (II) and the half metallocene cation complex represented by the above general formula (III) are further 0 to 3, preferably 0 to 1 neutral. 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.

  Further, 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 exist as a body or higher multimer.

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

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

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

(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 (VI), M represents a lanthanoid element, scandium or yttrium, and Cp ^{R ′} independently represents 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 triphenylcarbonium cation and tri (substituted phenyl) carbonium cation. Examples of the tri (substituted phenyl) carbonyl cation include 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 in the above reaction is a compound selected and combined from the above non-coordinating anions and cations, and is an N, N-dimethylaniline. Nitrotetrakis (pentafluorophenyl) borate, triphenylcarbonium tetrakis (pentafluorophenyl) borate and the like are preferable. In general formula [A] ⁺ [B] ^- ionic compounds represented by is preferably added from 0.1 to 10 mol per mol of the metallocene complex, more preferably it added about 1 molar. When the half metallocene cation complex represented by the general formula (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 ionic compound represented by the general formula [A] ⁺ [B] ⁻ used for the reaction are separately provided in the polymerization reaction system, and the general formula (III You may form the half metallocene cation complex represented by this. Further, by using a combination of a metallocene complex represented by the general formula (I) or the formula (II) and an ionic compound represented by the general formula [A] ⁺ [B] ^- , A half metallocene cation complex represented by the 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 above general formula (III) are preferably determined by X-ray structural analysis.

  The co-catalyst that can be used in the 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 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.

  On the other hand, 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, the content of the organoaluminum compound in the polymerization catalyst composition is preferably 1 to 50 times mol, more preferably about 10 times mol for the metallocene complex.

  Furthermore, in the polymerization catalyst composition, each of 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) is used as an appropriate promoter. By combining them, the amount of cis-1,4 bonds and the molecular weight of the resulting copolymer can be increased.

[Production Method of Copolymer (A1)]
The method for producing the copolymer (A1) includes a metallocene complex represented by the general formula (I) and the general formula (II) and a group consisting of a half metallocene cation complex represented by the general formula (III). It includes a step of addition polymerization of an aromatic vinyl compound and a conjugated diene compound in the presence of a polymerization catalyst composition containing at least one selected complex. Moreover, this manufacturing method can be made to be the same as that of the manufacturing method of the addition polymer by the addition polymerization reaction using the conventional coordination ion polymerization catalyst except using the polymerization catalyst composition mentioned above as a polymerization catalyst. Here, the production method includes, for example, (1) separately providing the components of the polymerization catalyst composition in a polymerization reaction system containing an aromatic vinyl compound and a conjugated diene compound as monomers, May be a polymerization catalyst composition, or (2) a previously prepared polymerization catalyst composition may be provided in the polymerization reaction system. Moreover, (2) includes providing a metallocene complex (active species) activated by a cocatalyst. In addition, the usage-amount of the metallocene complex contained in a polymerization catalyst composition has the preferable range of 1 / 10000-1 / 100 times mole with respect to a monomer.

  The addition polymerization reaction is preferably performed in an atmosphere of an inert gas, preferably nitrogen gas or argon gas.

  The polymerization temperature of the addition 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. When the polymerization temperature is raised, the cis-1,4 selectivity of the polymerization reaction may be lowered. On the other hand, the reaction time of the above addition polymerization reaction is not particularly limited, and is preferably in the range of, for example, 1 second to 10 days, but may be appropriately selected depending on conditions such as the type of monomer to be polymerized, the type of catalyst, and the polymerization temperature. Can do.

(Average molecular weight and molecular weight distribution of copolymer (A1))
Further, the number average molecular weight (Mn) of the obtained copolymer (A1) is not particularly limited, and the problem of lowering the molecular weight does not occur. Furthermore, the molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 3 or less, and more preferably 2 or less. Here, the average molecular weight and the molecular weight distribution can be determined using polystyrene as a standard substance by gel permeation chromatography (GPC).

[Rubber composition (B)]
The rubber composition (B) used for the run-flat tire of the present invention is characterized by containing the rubber component (A) containing the copolymer (A1), and preferably further contains a filler. Here, the blending amount of the filler is not particularly limited, but is preferably in the range of 10 to 200 parts by mass with respect to 100 parts by mass of the aromatic vinyl compound-conjugated diene compound copolymer. When the blending amount of the filler is less than 10 parts by mass, sufficient run-flat durability may not be obtained, and when it exceeds 200 parts by mass, workability may be deteriorated. Here, as the filler, carbon black and silica are preferable. The carbon black is preferably GPF, FEF, SRF, HAF, ISAF or SAF grade, more preferably HAF, ISAF or SAF grade. On the other hand, as silica, wet silica and dry silica are preferable, and wet silica is more preferable. These reinforcing fillers may be used alone or in a combination of two or more.

  In addition to the copolymer (A1) and filler, the rubber composition (B) includes compounding agents usually used in the rubber industry, such as anti-aging agents, softeners, silane coupling agents, additives. Sulfur accelerators, vulcanization accelerators, vulcanizers, and the like can be appropriately selected and blended within a range that does not impair the object of the present invention. As these compounding agents, commercially available products can be suitably used. The rubber composition of the present invention is produced by blending various compounding agents appropriately selected as necessary with an aromatic vinyl compound-conjugated diene compound copolymer, kneading, heating, extruding, and the like. Can do.

(Physical properties of vulcanized rubber of rubber composition (B))
(100% elongation stress (M100))
The rubber composition (B) according to the present invention preferably has a 100% elongation stress (M100) of 10 MPa or more as a vulcanized rubber property. When the stress (M100) is less than 10 MPa, the tire is greatly bent during the run-flat running, and the run-flat running durability of the tire is lowered. Preferable M100 is 10.5 MPa or more, and the upper limit thereof is not particularly limited, but is usually about 11 to 13 MPa in consideration of riding comfort and the like.

(Bend crack growth of vulcanized rubber composition)
The rubber composition (B) according to the present invention preferably has a high (index) flex crack growth property of the vulcanized rubber composition as a vulcanized rubber property. This means that the higher the index, the shorter the crack length grown by bending, and the greater the effect of suppressing the elongation of cracks generated during run-flat travel, resulting in excellent run-flat durability.

[tire]
Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing a cross section of one embodiment of the run-flat tire of the present invention. The tire shown in FIG. 1 is connected in a toroidal shape between a pair of left and right bead cores 1, and a carcass layer 2 composed of at least one radial carcass ply whose both ends are wound up from the tire inner side to the outer side, A side rubber layer 3 disposed on the outer side in the tire axial direction of the side region of the carcass layer 2 to form an outer portion, and a tread rubber layer 4 disposed on the outer side in the tire radial direction of the crown region of the carcass layer 2 to form a ground contact portion. A belt layer 5 disposed between the tread rubber layer 4 and the crown region of the carcass layer 2 to form a reinforcing belt, and an inner layer disposed on the entire inner surface of the carcass layer 2 to form an airtight film. A liner 6 is wound around the bead core 1 and the body portion of the carcass layer 2 extending from the one bead core 1 to the other bead core 1 ′. Between the carcass layer 2 and the inner liner 6 from the bead filler 7 side portion of the side region of the carcass layer to the shoulder region 10. At least one side portion of the reinforcing rubber 8 having a substantially crescent-shaped cross section along the rotation axis is provided. In addition, although the shape of the reinforcing rubber 8 at the side portion in the illustrated example has a crescent-shaped cross section, the cross-sectional shape is not particularly limited as long as it has a side reinforcing function.

  The run flat tire of the present invention is characterized in that any of the rubber members is applied to the rubber composition (B), and is preferably applied to a reinforced rubber. The rubber composition is preferably used as a reinforced rubber and / or a side rubber. It is particularly preferable to apply to bead fillers. This is because these rubber members are main rubber members that support the load by making it difficult to deform both side rubber layers when the internal pressure is abnormally lowered or punctured.

(Production of run-flat tires)
The run flat tire of the present invention is not particularly limited except that the rubber composition (B) is applied to any of the rubber members, and can be produced according to a conventional method. For example, they can be applied to tire treads, side and side reinforcement rubbers, bead fillers or other various rubber members. Preferably, the rubber composition (B) is used for the reinforcing rubber 8 and / or the bead filler 7 in the side portion, and the rubber composition (B) is manufactured by an ordinary run flat tire manufacturing method. That is, the rubber composition (B) containing various chemicals as described above is processed into each member at an unvulcanized stage, and is pasted and molded by a normal method on a tire molding machine to form a raw tire. The The green tire is heated and pressed in a vulcanizer to obtain a tire. Moreover, as gas with which this tire is filled, inert gas, such as nitrogen, argon, helium other than normal or the air which adjusted oxygen partial pressure, can be used. The run flat tire of the present invention thus obtained has improved run flat durability.

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

(Synthesis of half metallocene cation complex)
First, in Examples 1 and 2, the half metallocene cation complex represented by the general formula (III) used in common was synthesized, and its structure was confirmed by ¹ H-NMR and X-ray crystal structure analysis. ¹ H-NMR was measured at room temperature using THF-d8 as a solvent. X-ray crystal structure analysis was performed using RAXIS CS (Rigaku).
Under a nitrogen atmosphere, triethylanilinium tetrakisphenylborate (Et ₃ NHB (C ₆ H ₆ ) ₄ ) was added to 5 mL of a solution of (2-MeC ₉ H ₆ ) ₂ GdN (SiMe ₃ ) ₂ (0.150 g, 0.260 mmol) in THF. (0.110 g, 0.260 mmol) was added and stirred at room temperature for 12 hours. Thereafter, THF was distilled off under reduced pressure, and the resulting residue was washed three times with hexane to obtain an oily compound. The residue was recrystallized with a THF / hexane mixed solvent to produce [(2-MeC ₉ H ₆ ) GdN (SiMe ₃ ) ₂ (THF) ₃ ] [B (C ₆ F ₅ ) ₄ ] (150 mg as white crystals). 59%). The structure was confirmed by X-ray crystal analysis.

(Synthesis of polymer A1-A used in Example 1)
In a glove box under a nitrogen atmosphere, 104 g (1 mol) of styrene and 50 g of toluene were added to a well-dried 1 L pressure-resistant glass bottle, and the bottle was stoppered. Thereafter, the bottle was taken out from the glove box, and 54 g (1 mol) of 1,3-butadiene was charged to obtain a monomer solution. On the other hand, in a glove box under a nitrogen atmosphere, 40 μmol of bis (2-methylindenyl) gadolinium (trimethylsilylamide) [(2-MeC ₉ H ₆ ) ₂ GdN (SiMe ₃ ) ₂ ] was added to a glass container. ₄₀ μmol of phenylcarbonium tetrakis (pentafluorophenyl) borate (Ph ₃ CB (C ₆ F ₅ ) ₄ ) and 1 mmol of diisobutylaluminum halide were charged and dissolved in 10 ml of toluene to obtain a catalyst solution. Thereafter, the catalyst solution was taken out from the glove box, added to the monomer solution, and polymerized at 70 ° C. for 30 minutes. After the polymerization, the reaction was stopped by adding 10 ml of a 10 mass% methanol solution of 2,6-bis (t-butyl) -4-methylphenol (BHT), and the polymer was separated with a large amount of methanol / hydrochloric acid mixed solvent. And dried in vacuum at 60 ° C. The yield of the obtained polymer was 47 g.

(Synthesis of polymer A1-B used in Example 2)
Polymerization was carried out in the same manner as in Example 1 except that the amount of diisobutylaluminum halide used in the catalyst solution was 0.8 mmol. The yield of the obtained polymer was 46 g.

(Polymers C1 to C3 used in Comparative Examples 1 to 3)
In Comparative Examples 1 to 3, the following commercially available polymers (C1 to C3) were used.
* C1 Styrene-butadiene copolymer, manufactured by Asahi Kasei Chemical Co., Ltd., trade name: Toughden 2000.
* C2 Styrene-butadiene copolymer, manufactured by Asahi Kasei Chemical Co., Ltd., trade name: Toughden 1000.
* C3 Polybutadiene, manufactured by Asahi Kasei Chemical Co., Ltd., trade name: NF35.

(Polymers C4 to C6 used in Comparative Examples 4 to 6)
(Polymer C4)
In a glove box under a nitrogen atmosphere, in a well-dried 30 ml pressure-resistant glass bottle, dimethylaluminum (μ-dimethyl) bis (pentamethylcyclopentadienyl) samarium [(Cp ^* ) ₂ Sm (μ-Me) ₂ AlMe ₂ ] (Cp ^* : pentamethylcyclopentadienyl ligand) was charged in an amount of 0.03 mmol and dissolved in 1 ml of toluene. Subsequently, 0.09 mmol of triisobutylaluminum and 0.03 mmol of triphenylcarbonium tetrakis (pentafluorophenyl) borate (Ph ₃ CB (C ₆ F ₅ ) ₄ ) were added and the bottle was stoppered. Thereafter, the bottle was taken out from the glove box, charged with 0.49 g of 1,3-butadiene and 2.4 ml of styrene, and polymerized at 50 ° C. for 12 hours. After the polymerization, the reaction was stopped by adding 10 ml of a 10 mass% methanol solution of 2,6-bis (t-butyl) -4-methylphenol (BHT), and the polymer C4 was further mixed with a large amount of methanol / hydrochloric acid mixed solvent. Separate and vacuum dry at 60 ° C. The yield of the obtained polymer C4 was 20% by mass.

(Polymer C5)
A polymer C5 was obtained in the same manner as the polymer C4, except that 0.65 g of 1,3-butadiene and 2.0 ml of styrene were charged and polymerized at 50 ° C. for 6 hours. The yield of the obtained polymer C5 was 20% by mass.

(Polymer C6)
A 1.5 L autoclave with a stirrer was replaced with nitrogen, 300 ml of toluene as a solvent, 2.1 mmol of cyclopentadienyl titanium trichloride (CpTiCl ₃ ), 210 mmol of methylaluminoxane (MAO), 2.1 mmol of chloranil (CpTiCl ₃ / Chloranil = 1/1 (molar ratio)) was added, 37.5 ml of 1,3-butadiene and 37.5 ml of styrene were added, and polymerization was carried out at 60 ° C. for 30 minutes. Ten minutes after the start of polymerization, a methanol solution in which a small amount of pt-butylcatechol as a polymerization inhibitor was dissolved was added to the polymerization solution to stop the polymerization reaction. Polymer C6 was obtained by removing toluene from this solution.

  Polymers A1-A and A1-B used in Examples 1 and 2 produced as described above, polymers C1-C3 used in Comparative Examples 1 to 3 which are commercially available products, and conventional metallocene catalysts as described above were used. For the polymers C4 to C6 used in Comparative Examples 4 to 6 produced using the above, number average molecular weight (Mn), molecular weight distribution (Mw / Mn), microstructure, bound styrene content, block styrene content, glass transition point (Tg) ) And melting point (Tm) were measured by the following method. The results are shown in Table 1.

(Number average molecular weight (Mn) and molecular weight distribution (Mw / Mn))
Gel permeation chromatography [GPC: Tosoh HLC-8020, column: Tosoh GMH-XL (two in series), detector: differential refractometer (RI)], based on monodisperse polystyrene, The number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) in terms of polystyrene were determined.

(Microstructure and bound styrene content)
The microstructure of the polymer was determined from the integration ratio of ¹ H-NMR spectrum and ¹³ C-NMR spectrum, and the amount of bound styrene of the polymer was determined from the integration ratio of ¹ H-NMR spectrum. ¹ H-NMR and ¹³ C-NMR were measured at 120 ° C. using 1,1,2,2-tetrachloroethane as a solvent.

(Block styrene content)
The ratio of the block amount (block styrene content) in the NMR measurement of the repeating unit of the styrene portion to the total styrene portion was determined from the integral ratio of the ¹ H-NMR spectrum.

(Glass transition point (Tg) (° C) and melting point (Tm) (° C))
After weighing 10mg ± 0.5mg of sample, putting it in an aluminum measuring pan and covering it with a DSC device (TA Instruments) from room temperature to 50 ° C and stabilizing for 10 minutes The glass transition point (Tg) and the melting point (Tm) were measured while the temperature was raised to 50 ° C. at a rate of temperature increase of 10 ° C./min.

  From the detailed NMR data of the sample, no styrene-styrene bond was particularly confirmed.

(Preparation of rubber composition (B), production of pneumatic tire)
Next, using the rubber component (A) containing the polymer (A1), the rubber component (A) was blended according to the formulation shown in Table 2 and vulcanized under normal conditions to prepare a rubber composition (B). The physical properties (100% elongation stress (M100) and crack growth resistance) of the vulcanized rubber of the rubber composition (B) were measured and evaluated by the following methods. The results are shown in Table 2. Next, these rubber compositions (B)
1259135030153_0
The radial tires for passenger cars having tire sizes of 215 / 45ZR17 were manufactured according to the usual methods, and the run-flat durability of these tires was evaluated. Comparative examples were also evaluated in the same manner. The results are shown in Table 2. The maximum thickness of the side reinforcing layer was determined as a reinforcing rubber gauge and is shown in Table 2.

(Physical properties of vulcanized rubber of rubber composition)
(Measurement method of stress at 100% elongation (M100))
With respect to a slab sheet having a thickness of 2 mm obtained by vulcanizing the rubber composition (B) at 160 ° C. for 12 minutes, the stress at 100% elongation was measured based on JIS K 6251.

(Crack growth resistance: Measurement and indexing method of flex crack growth of vulcanized rubber composition)
Evaluation was performed in accordance with JIS K-6260 “Demach Bending Crack Test Method Bending Crack Growth Test”. About the reciprocal of the crack length which grew after 5000 bending | flexion, the value of the comparative example 1 was indexed as 100 (control). The higher the index, the shorter the crack length grown, indicating better crack growth resistance.

(Evaluation of run-flat tires)
(Run flat durability)
Each test tire (passenger car radial tire of tire size 215 / 45ZR17) is assembled with rims at normal pressure, filled with 230 kPa of internal pressure, left in a room at 38 ° C. for 24 hours, then the valve core is removed to increase the internal pressure. The drum running test was performed under the conditions of a pressure of 4.17 kN (425 kg), a speed of 89 km / h, and an indoor temperature of 38 ° C. as atmospheric pressure.
The travel distance until failure of each test tire was measured, and the travel distance of Comparative Example 1 was taken as 100, and the index was displayed by the following formula. The larger the index, the better the run flat durability.
Run-flat durability (index) = (travel distance of test tire / travel distance of tire of Comparative Example 1) × 100

* 1 TSR20
* 2 FEF (N550), Asahi Carbon Co., Ltd., Asahi # 60
* 3 Aromatic oil, Fujikosan "Aromax # 3"
* 4 N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine, “NOCRACK 6C” manufactured by Ouchi Shinsei Chemical Co., Ltd.
* 5 N, N'-dicyclohexyl-2-benzothiazylsulfenamide, "Noxeller DZ" manufactured by Ouchi Shinsei Chemical Co., Ltd.
* 6 Tetrakis (2-ethylhexyl) thiuram disulfide, “Noxeller TOT-N” manufactured by Ouchi Shinsei Chemical Co., Ltd.

In the tires (Examples 1 and 2) using the rubber composition (B) containing the rubber component (A) containing the copolymer (A1), the copolymer (A1) is converted into the conventional cis-1,4. Compared to tires (Comparative Examples 1 to 3) using rubber compositions composed of rubber components replaced with SBR or BR (copolymers C1 to C3) having a low bonding amount, run-flat durability significantly improves performance. It can be seen that the rubber composition (B) is excellent in crack growth resistance. Further, as the physical properties of the rubber composition (B), the stress at 100% elongation (M100) does not increase in the same range as the value of the control tire (12.9 MPa) (11.3 MPa, 11 .9 MPa), it can be understood that the rigidity in the tire radial direction does not increase and the riding comfort does not change during normal running when the tire is filled with the internal pressure.
Further, the tires of Examples 1 and 2 are tires using a rubber composition comprising a rubber component in which the copolymer (A1) is replaced with a polymer (C4 to C6) synthesized by a conventional metallocene catalyst system ( From comparison with Comparative Examples 4 to 6), it can be seen that the run-flat durability is greatly improved, and the physical properties of the rubber composition (B) are excellent in crack growth resistance. . Furthermore, in the comparative examples (7.2, 8.6, and 6.9 MPa, respectively) in which the stress at 100% elongation (M100) is less than 10 MPa, tire deflection during run-flat running increases, and the tire runs flat. In the examples (11.3 MPa, 11.9 MPa) in which the stress is properly secured while the durability is lowered, the rigidity of the tire during the run-flat running can be maintained and the tire run-flat can be maintained. It can be seen that the durability is greatly improved.

1 Bead core 2 Carcass layer 2a Folded carcass ply
2b Down carcass ply
3 Side rubber layer 4 Tread rubber layer 5 Belt layer 6 Inner liner 7 Bead filler 8 Side reinforcement rubber 10 Shoulder area

Claims (8)

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

(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, w represents an integer of 0 to 3, and the following general formula (III ):

(In the formula, M represents a lanthanoid element, scandium or yttrium, Cp ^{R ′} represents unsubstituted or substituted cyclopentadienyl, indenyl or fluorenyl, and X represents a hydrogen atom, a halogen atom, an alkoxide group or a thiolate group. represents an amide group, a silyl group or a hydrocarbon group having a carbon number of 1 to 20, L is a neutral Lewis base, w is, an integer of 0 to 3, [B] ^- is a non-coordinating Obtained by addition polymerization of an aromatic vinyl compound and a conjugated diene compound in the presence of a polymerization catalyst composition containing at least one complex selected from the group consisting of a half metallocene cation complex represented by A rubber containing a rubber component (A) containing an aromatic vinyl compound-conjugated diene compound copolymer (A1) having a cis-1,4 bond amount of 80% or more in the conjugated diene compound portion Run flat tire Narubutsu the (B) characterized by being applied to one of the rubber members.   The run-flat tire according to claim 1, wherein the copolymer (A1) has a vinyl bond content of a conjugated diene compound portion of 10% or less.   2. The orchid according to claim 1, wherein the copolymer (A1) has a block amount in the NMR measurement of the repeating unit of the aromatic vinyl compound portion of 10% or less of the total aromatic vinyl compound portion. Flat tire.   The run-flat tire according to claim 1, wherein the copolymer (A1) has a melting point (Tm) in DSC measurement.   The run-flat tire according to claim 1, wherein the copolymer (A1) is a styrene-butadiene copolymer.   The run-flat tire according to any one of claims 1 to 5, wherein the run-flat tire includes a reinforcing rubber on a side portion, and the rubber composition (B) is applied to the reinforcing rubber.   The run flat tire according to any one of claims 1 to 5, wherein the run flat tire includes a bead portion and a bead filler, and the rubber composition (B) is applied to the bead filler.   The run-flat tire includes a reinforcing rubber on a side portion, a bead portion and a bead filler, and the rubber composition (B) is applied to the reinforcing rubber and the bead filler. The run flat tire according to any one of the above.

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