JP5992772B2 - Rubber composition for tire and pneumatic tire - Google Patents

Description

The present invention relates to a rubber composition for tires and a pneumatic tire using the same.

In recent years, from the standpoints of resource and energy savings, as well as environmental protection, social demands for reducing carbon dioxide emissions have increased, and various countermeasures such as weight reduction and the use of electric energy have been considered for automobiles. ing. Therefore, it is required to reduce rolling resistance of automobile tires and improve fuel efficiency, and it is also desired to improve performance such as durability.

For example, as a method for reducing rolling resistance, there are known methods such as adoption of silica blending, weight reduction of filler, use of a filler having a small reinforcing property, etc. There is a tendency for performance to deteriorate.

Further, Patent Document 1 proposes the use of a mercapto-based silane coupling agent for the purpose of improving performance such as low fuel consumption, but generally a coupling reaction occurs before vulcanization and processability is improved. At present, polysulfide-based silane coupling agents that are difficult to react before vulcanization are mainly used. Therefore, it is desired to provide a silica rubber composition that is excellent in processability even when a mercapto silane coupling agent is used and has improved fuel economy and processability in a balanced manner.

JP 2009-126907 A

The object of the present invention is to solve the above-mentioned problems and provide a rubber composition for tires having improved fuel economy and processability in a well-balanced manner, and a pneumatic tire using the same.

（式中、Ｒ^１は、同一又は異なって、置換基を有してもよい炭素数３〜１５の１価の炭化水素基を表す。ｎは、２〜６の整数を表す。）

（式中、Ｒ^２は、同一又は異なって、置換基を有してもよい炭素数３〜１５の２価の炭化水素基を表す。ｍは、２〜６の整数を表す。） The present invention includes a rubber component, silica, a silane coupling agent having a mercapto group, and a polysulfide compound represented by the following formulas (I) and / or (II). The present invention relates to a tire rubber composition having a content of 10% by mass or more and a silica content of 10 to 70 parts by mass with respect to 100 parts by mass of the rubber component.

(In the formula, R ^1, same or different, .n representing a monovalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent, represents an integer from 2 to 6.)

(Wherein, R ² are the same or different, .m representing a divalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent, represents an integer from 2 to 6.)

The tire rubber composition is preferably obtained by kneading the polysulfide compound in a step prior to the vulcanizing chemical kneading step.
In the tire rubber composition, the content of the silane coupling agent having the mercapto group with respect to 100 parts by mass of the silica is 1 to 20 parts by mass, and the content of the polysulfide compound is 0.5 to 20 parts by mass. Is preferred.

（式（１）中、Ｒ^１０１〜Ｒ^１０３は、分岐若しくは非分岐の炭素数１〜１２のアルキル基、分岐若しくは非分岐の炭素数１〜１２のアルコキシ基、又は−Ｏ−（Ｒ^１１１−Ｏ）_ｚ−Ｒ^１１２（ｚ個のＲ^１１１は、分岐若しくは非分岐の炭素数１〜３０の２価の炭化水素基を表す。ｚ個のＲ^１１１はそれぞれ同一でも異なっていてもよい。Ｒ^１１２は、分岐若しくは非分岐の炭素数１〜３０のアルキル基、分岐若しくは非分岐の炭素数２〜３０のアルケニル基、炭素数６〜３０のアリール基、又は炭素数７〜３０のアラルキル基を表す。ｚは１〜３０の整数を表す。）で表される基を表す。Ｒ^１０１〜Ｒ^１０３はそれぞれ同一でも異なっていてもよい。Ｒ^１０４は、分岐若しくは非分岐の炭素数１〜６のアルキレン基を表す。）

（式（２）及び（３）中、Ｒ^２０１は水素、ハロゲン、分岐若しくは非分岐の炭素数１〜３０のアルキル基、分岐若しくは非分岐の炭素数２〜３０のアルケニル基、分岐若しくは非分岐の炭素数２〜３０のアルキニル基、又は該アルキル基の末端の水素が水酸基若しくはカルボキシル基で置換されたものを表す。Ｒ^２０２は分岐若しくは非分岐の炭素数１〜３０のアルキレン基、分岐若しくは非分岐の炭素数２〜３０のアルケニレン基、又は分岐若しくは非分岐の炭素数２〜３０のアルキニレン基を表す。Ｒ^２０１とＲ^２０２とで環構造を形成してもよい。） The silane coupling agent having a mercapto group comprises a compound represented by the following formula (1) and / or a binding unit A represented by the following formula (2) and a binding unit B represented by the following formula (3). It is preferable that it is a compound containing.

(In the formula (1), R ^{101 to} R ¹⁰³ are each a branched or unbranched C 1-12 alkyl group, a branched or unbranched C 1-12 alkoxy group, or —O— (R ¹¹¹ — O) _z- R ¹¹² (z R ¹¹¹ represents a branched or unbranched divalent hydrocarbon group having 1 to 30 carbon atoms. The z R ^{111 s} may be the same as or different from each other. ¹¹² represents a branched or unbranched alkyl group having 1 to 30 carbon atoms, a branched or unbranched alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an aralkyl group having 7 to 30 carbon atoms. Z represents an integer of 1 to 30.) R ^{101 to} R ¹⁰³ may be the same as or different from each other, and R ¹⁰⁴ has 1 to 6 carbon atoms which are branched or unbranched. Represents an alkylene group of

(In the formulas (2) and (3), R ²⁰¹ is hydrogen, halogen, branched or unbranched alkyl group having 1 to 30 carbon atoms, branched or unbranched alkenyl group having 2 to 30 carbon atoms, branched or unbranched. Or an alkyl group substituted with a hydroxyl group or a carboxyl group, and R ²⁰² represents a branched or unbranched C 1-30 alkylene group, branched or It represents an unbranched C2-C30 alkenylene group or a branched or unbranched C2-C30 alkynylene group, and R ²⁰¹ and R ²⁰² may form a ring structure.)

As the rubber composition for tires, the rubber component containing the isoprene-based rubber, the silica, the silane coupling agent having a mercapto group, and the polysulfide compound are kneaded, and the kneaded product obtained in the step 1 And a method obtained by a production method including kneading vulcanized chemicals 2 is preferable.
The present invention also relates to a pneumatic tire produced using the rubber composition.

According to the present invention, since it is a rubber composition for tires containing a predetermined amount of a specific rubber component, silica, a silane coupling agent having a mercapto group, and a specific polysulfide compound, fuel economy and processability are improved in a balanced manner. it can.

The rubber composition for tires of the present invention comprises a specific rubber component, silica, a silane coupling agent having a mercapto group, and a polysulfide compound represented by the formula (I) and / or (II) in a predetermined composition. .

A compound containing a specific rubber component and silica can be combined with a specific polysulfide compound and a mercapto-based silane coupling agent that can be expected to improve performance such as low fuel consumption, but there is a concern about deterioration of processability. Thus, the processability is improved, and at the same time, the effect of improving the fuel efficiency is exhibited, and the performance balance can be improved synergistically.

Furthermore, a normal rubber composition was obtained by a base kneading step of kneading chemicals other than vulcanizing chemicals (vulcanizing agent and vulcanizing accelerator) such as sulfur and sulfenamide vulcanization accelerators, and the step. The kneaded product is manufactured by performing a final kneading step in which kneaded chemicals are added and kneaded in this order, where the polysulfide compound is kneaded in a base kneading step performed before the final kneading step. Since the processability is dramatically improved and the fuel efficiency is greatly improved, the performance balance can be remarkably improved.

In the rubber composition, the rubber component includes a predetermined amount of styrene butadiene rubber (SBR).

SBR is not particularly limited, and those commonly used in the tire industry such as emulsion-polymerized styrene butadiene rubber (E-SBR), solution-polymerized styrene butadiene rubber (S-SBR), and these modified styrene butadiene rubbers can be used.

Moreover, as SBR, the thing modified | denatured by the modifier (modified | denatured SBR) can be used conveniently from the point that favorable low-fuel-consumption property is acquired. As the modified SBR, those obtained by treating SBR generally used in the tire industry with a modifying agent can be used. Examples of the modifier include 3-aminopropyldimethylmethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylethyldimethoxysilane, 3-aminopropyltrimethoxysilane, and 3- (2-aminoethylamino) propyl. Examples include trimethoxysilane, tin tetrachloride, butyltin trichloride, N-methylpyrrolidone and the like. These may be used alone or in combination of two or more.

The vinyl content of SBR is preferably 30% by mass or more, more preferably 50% by mass or more. If it is less than 30% by mass, fuel economy and wear resistance tend to deteriorate. The vinyl content is preferably 90% by mass or less, more preferably 70% by mass or less. If it exceeds 90% by mass, the fuel efficiency tends to deteriorate.
In the present invention, the vinyl content of SBR can be measured by infrared absorption spectrum analysis.

The styrene content of SBR is preferably 5% by mass or more, more preferably 10% by mass or more. If it is less than 5% by mass, sufficient rigidity may not be obtained. The styrene content is preferably 60% by mass or less, more preferably 50% by mass or less. If it exceeds 60% by mass, the heat build-up will remarkably increase and the fuel efficiency tends to decrease.
In the present invention, the styrene content of SBR is calculated by H ¹ -NMR measurement.

The content of SBR in 100% by mass of the rubber component is 10% by mass or more, preferably 30% by mass or more, more preferably 50% by mass or more, and further preferably 70% by mass or more. If the amount is less than 10% by mass, the effect of improving fuel economy tends to be difficult to obtain. Further, the content of the SBR is preferably 90% by mass or less, more preferably 85% by mass or less. If it exceeds 90 mass%, the fracture strength tends to decrease and the cost tends to increase.

As another rubber component used in combination with SBR, polyisoprene rubber can be preferably used. By blending the polyisoprene-based rubber, the rubber strength is improved, and the rubber grouping at the time of kneading is improved, so that productivity can be improved.

Examples of the polyisoprene rubber include natural rubber (NR) and polyisoprene rubber (IR). NR is not particularly limited. For example, SIR20, RSS # 3, TSR20, deproteinized natural rubber (DPNR), high purity natural rubber (HPNR), epoxidized natural rubber (ENR), etc., which are common in the tire industry Can be used. Similarly, IR that is common in the tire industry can be used.

When the rubber composition of the present invention contains a polyisoprene rubber, the content of the polyisoprene rubber in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 15% by mass or more. If it is less than 5% by mass, the effect of improving the breaking strength may not be sufficiently obtained. Further, the content of the polyisoprene rubber is preferably 50% by mass or less, more preferably 30% by mass or less. When it exceeds 50 mass%, workability tends to deteriorate.

Examples of other rubber components include butadiene rubber (BR), styrene isoprene (SIR), styrene isoprene butadiene rubber (SIBR), ethylene propylene diene rubber (EPDM), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR). And butyl rubber (IIR), and the like, and may be appropriately blended within a range not impairing the effects of the present invention. A rubber component may be used independently and may use 2 or more types together.

Examples of the silica include dry method silica (anhydrous silica), wet method silica (hydrous silica), and the like. Of these, wet-process silica is preferred because it has many silanol groups. Silica may be used alone or in combination of two or more.

The nitrogen adsorption specific surface area (N ₂ SA) of silica is preferably 30 m ² / g or more, more preferably 100 m ² / g or more, and preferably 300 m ² / g or less, more preferably 200 m ² / g. It is as follows. If it is in the said range, low-fuel-consumption property and workability will be obtained with sufficient balance.
The _N 2 SA of silica is a value measured by the BET method in accordance with ASTM D3037-81.

The content of silica is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and still more preferably 20 parts by mass or more with respect to 100 parts by mass of the rubber component. If it is less than 10 parts by mass, the reinforcing property is small, so that sufficient bending fatigue resistance and fracture strength may not be obtained. The silica content is preferably 70 parts by mass or less, more preferably 65 parts by mass or less. If it exceeds 70 parts by mass, it will be difficult for silica to be uniformly dispersed in the rubber composition, and not only the processability of the rubber composition will deteriorate but also the rolling resistance may increase.

（式（１）中、Ｒ^１０１〜Ｒ^１０３は、分岐若しくは非分岐の炭素数１〜１２のアルキル基、分岐若しくは非分岐の炭素数１〜１２のアルコキシ基、又は−Ｏ−（Ｒ^１１１−Ｏ）_ｚ−Ｒ^１１２（ｚ個のＲ^１１１は、分岐若しくは非分岐の炭素数１〜３０の２価の炭化水素基を表す。ｚ個のＲ^１１１はそれぞれ同一でも異なっていてもよい。Ｒ^１１２は、分岐若しくは非分岐の炭素数１〜３０のアルキル基、分岐若しくは非分岐の炭素数２〜３０のアルケニル基、炭素数６〜３０のアリール基、又は炭素数７〜３０のアラルキル基を表す。ｚは１〜３０の整数を表す。）で表される基を表す。Ｒ^１０１〜Ｒ^１０３はそれぞれ同一でも異なっていてもよい。Ｒ^１０４は、分岐若しくは非分岐の炭素数１〜６のアルキレン基を表す。）

（式（２）及び（３）中、Ｒ^２０１は水素、ハロゲン、分岐若しくは非分岐の炭素数１〜３０のアルキル基、分岐若しくは非分岐の炭素数２〜３０のアルケニル基、分岐若しくは非分岐の炭素数２〜３０のアルキニル基、又は該アルキル基の末端の水素が水酸基若しくはカルボキシル基で置換されたものを表す。Ｒ^２０２は分岐若しくは非分岐の炭素数１〜３０のアルキレン基、分岐若しくは非分岐の炭素数２〜３０のアルケニレン基、又は分岐若しくは非分岐の炭素数２〜３０のアルキニレン基を表す。Ｒ^２０１とＲ^２０２とで環構造を形成してもよい。） As a silane coupling agent having a mercapto group (-SH), a compound represented by the following formula (1) and / or a bond unit A represented by the following formula (2) and a bond represented by the following formula (3): A compound containing unit B can be preferably used.

(In the formula (1), R ^{101 to} R ¹⁰³ are each a branched or unbranched C 1-12 alkyl group, a branched or unbranched C 1-12 alkoxy group, or —O— (R ¹¹¹ — O) _z- R ¹¹² (z R ¹¹¹ represents a branched or unbranched divalent hydrocarbon group having 1 to 30 carbon atoms. The z R ^{111 s} may be the same as or different from each other. ¹¹² represents a branched or unbranched alkyl group having 1 to 30 carbon atoms, a branched or unbranched alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an aralkyl group having 7 to 30 carbon atoms. Z represents an integer of 1 to 30.) R ^{101 to} R ¹⁰³ may be the same as or different from each other, and R ¹⁰⁴ has 1 to 6 carbon atoms which are branched or unbranched. Represents an alkylene group of

(In the formulas (2) and (3), R ²⁰¹ is hydrogen, halogen, branched or unbranched alkyl group having 1 to 30 carbon atoms, branched or unbranched alkenyl group having 2 to 30 carbon atoms, branched or unbranched. Or an alkyl group substituted with a hydroxyl group or a carboxyl group, and R ²⁰² represents a branched or unbranched C 1-30 alkylene group, branched or It represents an unbranched C2-C30 alkenylene group or a branched or unbranched C2-C30 alkynylene group, and R ²⁰¹ and R ²⁰² may form a ring structure.)

Hereinafter, the compound represented by Formula (1) is demonstrated.

By using the compound represented by the formula (1), silica is dispersed well, the effects of the present invention can be obtained well, and the fuel economy can be remarkably improved.

R ^{101 to} R ¹⁰³ are each a branched or unbranched alkyl group having 1 to 12 carbon atoms, a branched or unbranched alkoxy group having 1 to 12 carbon atoms, or —O— (R ¹¹¹ —O) _z —R ¹¹² . Represents the group represented. From the viewpoint that the effect of the present invention can be obtained satisfactorily, at least one of R ^{101 to} R ¹⁰³ is preferably a group represented by —O— (R ¹¹¹ —O) _z —R ¹¹² , and two of them are — More preferably, it is a group represented by O— (R ¹¹¹ —O) _z —R ¹¹² , and one is a branched or unbranched C 1-12 alkoxy group.

Examples of the branched or unbranched alkyl group having 1 to 12 carbon atoms (preferably 1 to 5 carbon atoms) represented by R ^{101 to} R ¹⁰³ include, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and n-butyl. Group, iso-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group and the like.

Examples of the branched or unbranched alkoxy group having 1 to 12 carbon atoms (preferably 1 to 5 carbon atoms) of R ^{101 to} R ¹⁰³ include, for example, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n- Examples include butoxy, iso-butoxy, sec-butoxy, tert-butoxy, pentyloxy, hexyloxy, heptyloxy, 2-ethylhexyloxy, octyloxy, nonyloxy and the like.

In —O— (R ¹¹¹ —O) _z —R ¹¹² of R ^{101 to} R ¹⁰³ , R ¹¹¹ represents a branched or unbranched carbon number of 1 to 30 (preferably having 1 to 15 carbon atoms, more preferably 1 carbon number). To 3) a divalent hydrocarbon group.
Examples of the hydrocarbon group include a branched or unbranched alkylene group having 1 to 30 carbon atoms, a branched or unbranched alkenylene group having 2 to 30 carbon atoms, and a branched or unbranched alkynylene group having 2 to 30 carbon atoms. And an arylene group having 6 to 30 carbon atoms. Of these, a branched or unbranched alkylene group having 1 to 30 carbon atoms is preferable.

Examples of the branched or unbranched alkylene group having 1 to 30 carbon atoms (preferably 1 to 15 carbon atoms, more preferably 1 to 3 carbon atoms) of R ¹¹¹ include, for example, a methylene group, an ethylene group, a propylene group, and a butylene group. Pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decylene group, undecylene group, dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, hexadecylene group, heptadecylene group, octadecylene group and the like.

Examples of the branched or unbranched carbon atoms 2-30 alkenylene group (preferably 2 to 15 carbon atoms, more preferably 2 to 3 carbon atoms) of R ^111, for example, vinylene group, propenylene group, 2-propenylene Group, 1-butenylene group, 2-butenylene group, 1-pentenylene group, 2-pentenylene group, 1-hexenylene group, 2-hexenylene group, 1-octenylene group and the like.

Examples of the branched or unbranched carbon atoms 2-30 alkynylene group (preferably 2 to 15 carbon atoms, more preferably 2 to 3 carbon atoms) of R ^111, for example, ethynylene group, propynylene group, butynylene group, pentynylene group Hexynylene group, heptynylene group, octynylene group, noninylene group, decynylene group, undecynylene group, dodecynylene group and the like.

Examples of the arylene group having 6 to 30 carbon atoms (preferably 6 to 15 carbon atoms) of R ¹¹¹ include a phenylene group, a tolylene group, a xylylene group, and a naphthylene group.

z represents an integer of 1 to 30 (preferably 2 to 20, more preferably 3 to 7, further preferably 5 to 6).

R ¹¹² represents a branched or unbranched alkyl group having 1 to 30 carbon atoms, a branched or unbranched alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an aralkyl group having 7 to 30 carbon atoms. Represent. Of these, a branched or unbranched alkyl group having 1 to 30 carbon atoms is preferable.

Examples of the branched or unbranched alkyl group having 1 to 30 carbon atoms (preferably 3 to 25 carbon atoms, more preferably 10 to 15 carbon atoms) of R ¹¹² include, for example, a methyl group, an ethyl group, an n-propyl group, Isopropyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, 2-ethylhexyl, octyl, nonyl, decyl, undecyl , Dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, octadecyl group and the like.

Examples of the branched or unbranched alkenyl group having 2 to 30 carbon atoms (preferably 3 to 25 carbon atoms, more preferably 10 to 15 carbon atoms) for R ¹¹² include, for example, a vinyl group, a 1-propenyl group, and 2-propenyl. Group, 1-butenyl group, 2-butenyl group, 1-pentenyl group, 2-pentenyl group, 1-hexenyl group, 2-hexenyl group, 1-octenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group Group, pentadecenyl group, octadecenyl group and the like.

Examples of the aryl group having 6 to 30 carbon atoms (preferably 10 to 20 carbon atoms) of R ¹¹² include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and a biphenyl group.

Examples of the aralkyl group having 7 to 30 carbon atoms (preferably 10 to 20 carbon atoms) of R ¹¹² include a benzyl group and a phenethyl group.

Specific examples of the group represented by —O— (R ¹¹¹ —O) _z —R ¹¹² include, for example, —O— (C ₂ H ₄ —O) ₅ —C ₁₁ H ₂₃ , —O— (C _{2 H 4 -O) 5 -C 12 H} 25, -O- (C 2 H 4 -O) 5 -C 13 H 27, -O- (C 2 H 4 -O) 5 -C 14 H 29, -O _{- (C 2 H 4 -O)} 5 -C 15 H 31, -O- (C 2 H 4 -O) 3 -C 13 H 27, -O- (C 2 H 4 -O) 4 -C 13 H _{27, -O- (C 2 H 4} -O) 6 -C 13 H 27, such as _{-O- (C 2 H 4 -O)} 7 -C 13 H 27 and the like. Among _{these, -O- (C 2 H 4 -O} ) 5 -C 11 H 23, -O- (C 2 H 4 -O) 5 -C 13 H 27, -O- (C 2 H 4 -O) 5 _{-C 15 H 31, -O- (C} 2 H 4 -O) 6 -C 13 H 27 are preferable.

Examples of the branched or unbranched alkylene group having 1 to 6 carbon atoms (preferably 1 to 5 carbon atoms) of R ¹⁰⁴ include the same groups as the branched or unbranched alkylene group having 1 to 30 carbon atoms of R ^111. Can give.

Examples of the compound represented by the formula (1) include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and the following formula: The compound represented by the following formula (Si363 manufactured by EVONIK-DEGUSSA) and the like can be used, and a compound represented by the following formula can be preferably used. These may be used alone or in combination of two or more.

Next, the compound containing the bond unit A represented by the formula (2) and the bond unit B represented by the formula (3) will be described.

The compound containing the bond unit A represented by the formula (2) and the bond unit B represented by the formula (3) is more viscous during processing than a polysulfide silane such as bis- (3-triethoxysilylpropyl) tetrasulfide. The rise is suppressed. This is presumably because the increase in Mooney viscosity is small because the sulfide portion of the bond unit A is a C—S—C bond and is thermally stable compared to tetrasulfide and disulfide.

Moreover, the shortening of the scorch time is suppressed as compared with mercaptosilane such as 3-mercaptopropyltrimethoxysilane. This is because the bonding unit B has a structure of mercaptosilane, but the —C ₇ H ₁₅ part of the bonding unit A covers the —SH group of the bonding unit B, so that it does not easily react with the polymer and scorch is not easily generated. This is probably because of this.

In the silane coupling agent having the above structure, the content of the bond unit A is preferably 30 from the viewpoint that the effect of suppressing the increase in viscosity during processing and the effect of suppressing the shortening of the scorch time can be enhanced. It is at least mol%, more preferably at least 50 mol%, preferably at most 99 mol%, more preferably at most 90 mol%. Further, the content of the bond unit B is preferably 1 mol% or more, more preferably 5 mol% or more, further preferably 10 mol% or more, preferably 70 mol% or less, more preferably 65 mol% or less, More preferably, it is 55 mol% or less. Further, the total content of the binding units A and B is preferably 95 mol% or more, more preferably 98 mol% or more, and particularly preferably 100 mol%.
The content of the bond units A and B is an amount including the case where the bond units A and B are located at the terminal of the silane coupling agent. The form in which the bonding units A and B are located at the end of the silane coupling agent is not particularly limited, as long as the units corresponding to the formulas (2) and (3) indicating the bonding units A and B are formed. .

Examples of the halogen for R ²⁰¹ include chlorine, bromine, and fluorine.

^Examples of the branched or unbranched alkyl group having 1 to 30 carbon atoms of R ²⁰¹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, iso-butyl group, sec-butyl group, tert- Examples thereof include a butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, and a decyl group. The number of carbon atoms of the alkyl group is preferably 1-12.

^Examples of the branched or unbranched C 2-30 alkenyl group of R ²⁰¹ include a vinyl group, 1-propenyl group, 2-propenyl group, 1-butenyl group, 2-butenyl group, 1-pentenyl group, and 2-pentenyl. Group, 1-hexenyl group, 2-hexenyl group, 1-octenyl group and the like. The alkenyl group preferably has 2 to 12 carbon atoms.

^Examples of the branched or unbranched alkynyl group having 2 to 30 carbon atoms of R ²⁰¹ include ethynyl group, propynyl group, butynyl group, pentynyl group, hexynyl group, heptynyl group, octynyl group, nonynyl group, decynyl group, undecynyl group, And dodecynyl group. The alkynyl group preferably has 2 to 12 carbon atoms.

Examples of the branched or unbranched alkylene group having 1 to 30 carbon atoms of R ²⁰² include an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, Examples include dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, hexadecylene group, heptadecylene group, octadecylene group and the like. The alkylene group preferably has 1 to 12 carbon atoms.

^Examples of the branched or unbranched C2-C30 alkenylene group of R202 include vinylene group, 1-propenylene group, 2-propenylene group, 1-butenylene group, 2-butenylene group, 1-pentenylene group and 2-pentenylene. Group, 1-hexenylene group, 2-hexenylene group, 1-octenylene group and the like. The alkenylene group preferably has 2 to 12 carbon atoms.

Examples of the branched or unbranched alkynylene group having 2 to 30 carbon atoms of R ²⁰² include ethynylene group, propynylene group, butynylene group, pentynylene group, hexynylene group, heptynylene group, octynylene group, noninylene group, decynylene group, undecynylene group, And dodecynylene group. The alkynylene group preferably has 2 to 12 carbon atoms.

In the compound containing the bond unit A represented by the formula (2) and the bond unit B represented by the formula (3), the repetition of the total of the repeating number (x) of the bonding unit A and the repeating number (y) of the bonding unit B The number (x + y) is preferably in the range of 3 to 300. Within this range, since the mercaptosilane of the bond unit B is covered by —C ₇ H ₁₅ of the bond unit A, it is possible to suppress the scorch time from being shortened and to have good reactivity with silica and rubber components. Can be secured.

For example, NXT-Z30, NXT-Z45, NXT-Z60, etc. manufactured by Momentive are used as the compound containing the binding unit A represented by the formula (2) and the coupling unit B represented by the formula (3). Can do. These may be used alone or in combination of two or more.

The content of the silane coupling agent having a mercapto group is preferably 1 part by mass or more, more preferably 2 parts by mass or more with respect to 100 parts by mass of silica. If it is less than 1 part by mass, there is a possibility that the effect of improving the fuel efficiency cannot be sufficiently obtained. Moreover, this content becomes like this. Preferably it is 20 mass parts or less, More preferably, it is 10 mass parts or less, More preferably, it is 6 mass parts or less. If it exceeds 20 parts by mass, the rubber strength tends to decrease.

The rubber composition of the present invention preferably contains carbon black as a reinforcing filler in addition to silica. Carbon black that can be used is not particularly limited, and those generally used in the tire industry such as GPF, FEF, HAF, ISAF, and SAF can be used. These may be used alone or in combination of two or more.

The nitrogen adsorption specific surface area _(N 2 SA) of carbon black is preferably ^{50 m} 2 / g or more, more preferably ^{85 m} 2 / g or more, preferably 150 meters ² / g or less, more preferably 105m ² / g or less. The DBP oil absorption of carbon black is preferably 80 ml / 100 g or more, more preferably 110 ml / 100 g or more, and preferably 180 ml / 100 g or less, more preferably 140 ml / 100 g or less. If these properties are less than the lower limit, sufficient reinforcing properties may not be obtained. When the upper limit is exceeded, workability tends to deteriorate. The nitrogen adsorption specific surface area of carbon black is measured according to JIS K6217-2: 2001, and the dibutyl phthalate (DBP) oil absorption is measured according to JIS K6217-4: 2001.

The content of carbon black is preferably 1 part by mass or more, more preferably 3 parts by mass or more with respect to 100 parts by mass of the rubber component. If the amount is less than 1 part by mass, sufficient reinforcement may not be obtained. The carbon black content is preferably 90 parts by mass or less, more preferably 85 parts by mass or less. If it exceeds 90 parts by mass, the fuel efficiency tends to deteriorate.

In the rubber composition of the present invention, the total content of silica and carbon black is preferably 40 parts by mass or more, more preferably 55 parts by mass or more with respect to 100 parts by mass of the rubber component. If the amount is less than 40 parts by mass, sufficient reinforcement may not be obtained. The total content is preferably 200 parts by mass or less, more preferably 150 parts by mass or less. If the amount exceeds 200 parts by mass, sufficient fuel economy and processability may not be obtained.

When the rubber composition of the present invention contains both components of silica and carbon black, from the viewpoint of the performance balance, the content of silica in 100% by mass of both components is preferably 50% by mass or more, more preferably Is 70% by mass or more, more preferably 80% by mass or more, and preferably 95% by mass or less, more preferably 85% by mass or less.

（式中、Ｒ^１は、同一又は異なって、置換基を有してもよい炭素数３〜１５の１価の炭化水素基を表す。ｎは、２〜６の整数を表す。）

（式中、Ｒ^２は、同一又は異なって、置換基を有してもよい炭素数３〜１５の２価の炭化水素基を表す。ｍは、２〜６の整数を表す。） In the present invention, a polysulfide compound represented by the following formula (I) and / or (II) is used.

(In the formula, R ^1, same or different, .n representing a monovalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent, represents an integer from 2 to 6.)

(Wherein, R ² are the same or different, .m representing a divalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent, represents an integer from 2 to 6.)

In the above formula (I), R ¹ is a monovalent hydrocarbon group having 3 to 15 carbon atoms which may have a substituent, and the carbon number is preferably 5 to 12, more preferably 6 -10. The monovalent hydrocarbon group for R ¹ may be linear, branched or cyclic, and any of saturated and unsaturated hydrocarbon groups (aliphatic, alicyclic, aromatic hydrocarbon groups, etc.) But you can. Of these, an aromatic hydrocarbon group which may have a substituent is preferable.

Examples of R ¹ include an alkyl group having 3 to 15 carbon atoms, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group, an aralkyl group, and a substituted aralkyl group. Among these, an aralkyl group and a substituted aralkyl group are exemplified. preferable. Here, examples of the alkyl group include a butyl group and an octyl group; examples of the cycloalkyl group include a cyclohexyl group; examples of the aralkyl group include a benzyl group and a phenethyl group; and examples of the substituent include an oxo group (═O). And polar groups such as hydroxy group, carboxyl group, carbonyl group, amino group, acetyl group, amide group and imide group.

In the above formula (I), n is an integer of 2 to 6, preferably 2 to 3, and more preferably 2.

In the formula (II), R ² is a divalent hydrocarbon group having 3 to 15 carbon atoms which may have a substituent, and the carbon number is preferably 3 to 10, more preferably 4 ~ 8. The divalent hydrocarbon group for R ² may be linear, branched, or cyclic, and any of saturated and unsaturated hydrocarbon groups (aliphatic, alicyclic, aromatic hydrocarbon groups, etc.) But you can. Especially, the aliphatic hydrocarbon group which may have a substituent is preferable, and a linear aliphatic hydrocarbon group is more preferable.

Examples of R ² include an alkylene group having 3 to 15 carbon atoms and a substituted alkylene group. Here, examples of the alkylene group include a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, and a nonylene group, and examples of the substituent include those similar to the substituent for R ¹ .

In the above formula (I), m is an integer of 2 to 6, preferably 2 to 3, and more preferably 2.

Specific examples of the polysulfide compound represented by the above formulas (I) and (II) include N, N′-di (γ-butyrolactam) disulfide, N, N′-di (5-methyl-γ-butyrolactam) disulfide, N, N′-di (5-ethyl-γ-butyrolactam) disulfide, N, N′-di (5-isopropyl-γ-butyrolactam) disulfide, N, N′-di (5-methoxy-γ-butyrolactam) disulfide N, N′-di (5-ethoxy-γ-butyrolactam) disulfide, N, N′-di (5-chloro-γ-butyrolactam) disulfide, N, N′-di (5-nitro-γ-butyrolactam) Disulfide, N, N'-di (5-amino-γ-butyrolactam) disulfide, N, N'-di (δ-valerolactam) disulfide, N, N'-di (δ- Caprolactam) disulfide, N, N'-di (ε-caprolactam) disulfide, N, N'-di (3-methyl-δ-caprolactam) disulfide, N, N'-di (3-ethyl-ε-caprolactam) disulfide N, N′-di (3-isopropyl-ε-caprolactam) disulfide, N, N′-di (δ-methoxy-ε-caprolactam) disulfide, N, N′-di (3-ethoxy-ε-caprolactam) Disulfide, N, N′-di (3-chloro-ε-caprolactam) disulfide, N, N′-di (δ-nitro-ε-caprolactam) disulfide, N, N′-di (3-amino-ε-caprolactam ) Disulfide, N, N′-di (ω-heptalactam) disulfide, N, N′-di (ω-octalactam) disulfide, dithiodica Rorakutamu, morpholine disulfide, N-benzyl-N - [(dibenzylamino) disulfanyl] phenylmethanamine (N, N'- dithiobis (dibenzyl amine)), and the like. These polysulfide compounds may be used alone or in combination of two or more.

The content of the polysulfide compound is preferably 0.5 parts by mass or more, more preferably 1.5 parts by mass or more with respect to 100 parts by mass of the silica. If it is less than 0.5 parts by mass, good workability cannot be ensured, and the performance balance may not be sufficiently improved. Moreover, this content becomes like this. Preferably it is 20 mass parts or less, More preferably, it is 13 mass parts or less, More preferably, it is 10 mass parts or less. If it exceeds 20 parts by mass, the workability may be reduced.

Further, the content of the polysulfide compound is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, with respect to 100 parts by mass of the silane coupling agent having a mercapto group. Moreover, this content becomes like this. Preferably it is 250 mass parts or less, More preferably, it is 150 mass parts or less. When it is less than the lower limit, when it exceeds the upper limit, there is a tendency similar to the above.

The rubber composition of the present invention usually contains a vulcanized chemical that is added and kneaded in the final kneading step. Examples of vulcanizing chemicals include vulcanizing agents and vulcanization accelerators.

Examples of the vulcanizing agent include sulfur such as powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, and insoluble sulfur.

When the rubber composition of the present invention contains sulfur, the content thereof is preferably 0.5 parts by mass or more, more preferably 1.5 parts by mass or more with respect to 100 parts by mass of the rubber component. If it is less than 0.5 mass part, there is little bridge | crosslinking and there exists a possibility that various rubber physical properties may deteriorate. Moreover, this content becomes like this. Preferably it is 6.0 mass parts or less, More preferably, it is 4.0 mass parts or less. If it exceeds 6.0 parts by mass, the rubber strength tends to decrease.

Examples of the vulcanization accelerator include sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamic acid, aldehyde-amine or aldehyde-ammonia, imidazoline, and xanthate vulcanization accelerators. Among them, sulfenamide-based and guanidine-based vulcanization accelerators are preferable from the viewpoint of excellent vulcanization characteristics.

Examples of the sulfenamide vulcanization accelerator include CBS (N-cyclohexyl-2-benzothiazylsulfenamide), TBBS (Nt-butyl-2-benzothiazylsulfenamide), N, N-dicyclohexyl. -2-benzothiazylsulfenamide and the like, and examples of the guanidine vulcanization accelerator include diphenylguanidine (DPG).

When the rubber composition of the present invention contains a vulcanization accelerator, the content thereof is preferably 0.7 parts by mass or more, more preferably 1.2 parts by mass or more with respect to 100 parts by mass of the rubber component. . If it is less than 0.7 parts by mass, the vulcanization start time tends to be delayed. Moreover, this content becomes like this. Preferably it is 5.0 mass parts or less, More preferably, it is 3.5 mass parts or less. If it exceeds 5.0 parts by mass, the vulcanization speed is high, and there is a possibility that scorch occurs during processing.

In the rubber composition of the present invention, various materials generally used in the tire industry such as oil, stearic acid, zinc oxide, anti-aging agent, plasticizer, lubricant, wax and the like are appropriately blended in addition to the above components. It may be.

As a method for producing the rubber composition of the present invention, known methods can be used. For example, the above components are kneaded using a rubber kneading device such as an open roll or a Banbury mixer, and then vulcanized (crosslinked). It can be manufactured by a method or the like.

Among them, it is preferable to prepare the polysulfide compound by kneading in the step before the vulcanizing chemical kneading step. For example, the rubber component, silica, a silane coupling agent having a mercapto group, and the polysulfide compound are kneaded. It can be suitably produced by a production method comprising Step 1 and Step 2 of kneading the kneaded product and vulcanized chemical obtained in Step 1. In this case, the processability is dramatically improved and the fuel efficiency is remarkably improved.

(Process 1 (base kneading process 1))
In step 1, the rubber component, silica, a silane coupling agent having a mercapto group, and a polysulfide compound are kneaded. The kneading method is not particularly limited, and a kneader used in a general rubber industry such as a Banbury mixer or an open roll can be used. The base kneading step may be performed once, but the number of kneading is not particularly limited, such as dividing the additive or increasing the kneading.

The kneading temperature in step 1 is preferably 50 ° C. or higher, more preferably 80 ° C. or higher, and preferably 200 ° C. or lower, more preferably 190 ° C. or lower. The kneading time is not particularly limited, but is usually 30 seconds to 30 minutes, preferably 1 to 30 minutes. If it is less than the lower limit, the reaction between the silane coupling agent and silica does not proceed sufficiently, silica cannot be dispersed well, and the effect of improving rubber properties tends to be small. On the other hand, when the upper limit is exceeded, the Mooney viscosity increases and the processability tends to deteriorate.

The rubber component kneaded in step 1 is preferably 60% by mass or more, more preferably 80% by mass or more, and still more preferably 100% when the total amount is 100% by mass from the viewpoint that the effects of the present invention can be obtained satisfactorily. % By mass.

(Process 2 (finishing process))
After performing Step 1, the kneaded product obtained in Step 1 is cooled, and further vulcanized chemicals such as a vulcanizing agent and a vulcanization accelerator are added and kneaded to obtain an unvulcanized rubber composition.

The kneading temperature in step 2 is usually 100 ° C. or lower, and preferably room temperature (20 ° C.) to 80 ° C. If the temperature exceeds 100 ° C., rubber scorch may occur. The kneading time in step 2 is not particularly limited, but is usually 30 seconds or longer, preferably 1 to 30 minutes.

(Process 3 (vulcanization process))
The rubber composition of the present invention is obtained by vulcanizing the unvulcanized rubber composition obtained in step 3 by a known method. The vulcanization temperature in step 3 is preferably 120 ° C. or higher, more preferably 140 ° C. or higher, and preferably 200 ° C. or lower, more preferably 180 ° C. or lower, from the viewpoint that the effects of the present invention can be obtained satisfactorily. It is.

The timing of kneading the appropriately added compounding materials (carbon black, zinc oxide, plasticizer, lubricant, wax, oil, stearic acid, zinc oxide, anti-aging agent, etc.) is not particularly limited. It is preferable.

The rubber composition of the present invention can be used for each member of a tire and can be suitably used for a base tread.

The pneumatic tire of the present invention is manufactured by a usual method. That is, the rubber composition is kneaded using a normal processing method, and the resulting unvulcanized rubber composition is extruded into the shape of a two-layer tread composed of a base tread and a cap tread. The unvulcanized tire is formed by pasting together with other members by a usual method. The unvulcanized tire can be heated and pressurized in a vulcanizer to obtain the pneumatic tire of the present invention.

The pneumatic tire of the present invention can be suitably used as a tire for passenger cars.

The present invention will be specifically described based on examples, but the present invention is not limited to these examples.

Hereinafter, various chemicals used in Examples and Comparative Examples will be described together.
NR: RSS # 3
SBR: NS116R manufactured by Nippon Zeon Co., Ltd. (S-SBR modified at one end with N-methylpyrrolidone, styrene content: 22% by mass, vinyl bond content: 65% by mass)
Silica: Ultrazil VN3 manufactured by Degussa (N ₂ SA: 175 m ² / g)
Silane coupling agent 1: Si69 (bis (3-triethoxysilylpropyl) tetrasulfide) manufactured by EVONIK-DEGUSSA
Silane coupling agent 2: NXT-Z45 manufactured by Momentive (compound containing bonding unit A and bonding unit B (bonding unit A: 55 mol%, bonding unit B: 45 mol%))
Silane coupling agent 3: Si363 manufactured by EVONIK-DEGUSSA
Carbon black: Dia Black N339 manufactured by Mitsubishi Chemical Corporation (N ₂ SA: 96 m ² / g, DBP absorption: 124 ml / 100 g)
Oil: X-140 manufactured by Japan Energy Co., Ltd.
Anti-aging agent: Antigen 6C (N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine) manufactured by Sumitomo Chemical Co., Ltd.
Stearic acid: Stearic acid “椿” manufactured by NOF Corporation
Zinc oxide: Zinc Hua 1 manufactured by Mitsui Mining & Smelting Co., Ltd. Wax: Sunnock N manufactured by Ouchi Shinsei Chemical Co., Ltd.
Polysulfide compound 1: dithiodicaprolactam (manufactured by Sanshin Chemical Co., Ltd.)
Polysulfide compound 2: N-benzyl-N-[(dibenzylamino) disulfanyl] phenylmethanamine (manufactured by Aldrich)
Sulfur: Powder sulfur vulcanization accelerator manufactured by Tsurumi Chemical Industry Co., Ltd .: Soxinol CZ manufactured by Sumitomo Chemical Co., Ltd.

<Examples and Comparative Examples>
Using a 1.7 L Banbury mixer manufactured by Kobe Steel Co., Ltd., the materials described in the item of base kneading in Table 1 were kneaded for 5 minutes at 150 ° C. to obtain a kneaded material (base kneading Process). Next, the materials described in the item of finish kneading in Table 1 are added to the kneaded material obtained, and kneaded for 3 minutes under the condition of 80 ° C. using an open roll to obtain an unvulcanized rubber composition. Obtained (finishing and kneading step).
The obtained unvulcanized rubber composition was press vulcanized at 170 ° C. for 20 minutes to obtain a vulcanized rubber composition.

Further, the obtained unvulcanized rubber composition is molded into a base tread shape and bonded together with other tire members on a tire molding machine to form an unvulcanized tire, and then press vulcanized at 170 ° C. for 12 minutes. Thus, a test tire (size: 195 / 65R15) was manufactured.

The following evaluation was performed about the obtained unvulcanized rubber composition, the vulcanized rubber composition, and the test tire. The results are shown in Table 1.

(Processability index 1 (Mooney viscosity))
About the obtained unvulcanized rubber composition, the Mooney viscosity based on JISK6300 was measured at 130 degreeC. The Mooney viscosity (ML _{1 + 4} ) of Comparative Example 1 was set to 100, and indexed by the following formula (Mooney viscosity index). The larger the index, the lower the Mooney viscosity and the better the processability.
(Mooney viscosity index) = (ML _{1 + 4} of Comparative Example 1) / (ML _{1 + 4 of} each formulation) × 100

(Processability index 2 (sheet smoothness))
As for the smoothness of the rubber sheet after the roll processing, the 5-level sensory evaluation was performed with the smoothness of the surface and the edge as 3 as a reference, and the average value was defined as the smoothness of the rubber sheet. Larger numbers are better.

(Viscoelasticity test (low fuel consumption 1))
A test piece of a predetermined size was cut out from the vulcanized rubber composition, using a viscoelastic spectrometer manufactured by Ueshima Seisakusho Co., Ltd. at 30 ° C. under conditions of an initial strain of 10%, a dynamic strain of 2%, and a frequency of 10 Hz. The loss tangent (tan δ) of the vulcanized rubber sheet was measured. The tan δ of Comparative Example 1 was set to 100, and the index was displayed by the following calculation formula (low fuel consumption index 1). The larger the index, the better the fuel efficiency.
(Low fuel consumption index) = (tan δ of Comparative Example 1) / (tan δ of each formulation) × 100

(Rolling resistance (low fuel consumption 2))
Using a rolling resistance tester, the rolling resistance when a test tire is run at a rim (15 × 6JJ), internal pressure (230 kPa), load (3.43 kN), speed (80 km / h) is measured and compared. It was displayed as an index when Example 1 was set to 100 (low fuel consumption index 2). Larger values indicate lower rolling resistance and better fuel efficiency.

In Comparative Examples 1 to 3 in which Si69 is used as the silane coupling agent and the polysulfide compound is not blended and the mercapto-based silane coupling agent is substituted, the processability is reduced, and the polysulfide compound is used. In Comparative Examples 5 and 7 to which was added, the processability was lowered, and the improvement effect of the low fuel consumption was not seen. On the other hand, in the example in which the mercapto-based silane coupling agent and the polysulfide compound are blended, the improvement effect of the workability is exhibited and the fuel efficiency is greatly improved, and the balance of performance can be improved synergistically. Became clear.

Claims (4)

Step 1 for kneading a rubber component, silica, a silane coupling agent having a mercapto group, and a polysulfide compound represented by the following formula (I) and / or (II) , and the kneaded product and vulcanization obtained in Step 1 Obtained by a production method including the step 2 of kneading a chemical ,
In 100% by mass of the rubber component, the content of styrene butadiene rubber is 10% by mass or more,
The content of the silica to the rubber component 100 parts by mass Ri 10-70 parts by der,
The polysulfide compound content rubber composition for a tire Ru 0.5 to 20 parts by mass der of with respect to the 100 parts by mass of silica.

(In the formula, R ^1, same or different, .n representing a monovalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent, represents an integer from 2 to 6.)

(Wherein, R ² are the same or different, .m representing a divalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent, represents an integer from 2 to 6.) Claim 1 The tire rubber composition according content is 1 to 20 parts by weight of a silane coupling agent having an mercapto group relative to the 100 parts by mass of silica. The silane coupling agent having the mercapto group comprises a compound represented by the following formula (1) and / or a binding unit A represented by the following formula (2) and a binding unit B represented by the following formula (3). a compound is claimed in claim 1 or 2 tire rubber composition according comprising.

(In the formula (1), R ^{101 to} R ¹⁰³ are each a branched or unbranched C 1-12 alkyl group, a branched or unbranched C 1-12 alkoxy group, or —O— (R ¹¹¹ — O) _z- R ¹¹² (z R ¹¹¹ represents a branched or unbranched divalent hydrocarbon group having 1 to 30 carbon atoms. The z R ^{111 s} may be the same as or different from each other. ¹¹² represents a branched or unbranched alkyl group having 1 to 30 carbon atoms, a branched or unbranched alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an aralkyl group having 7 to 30 carbon atoms. Z represents an integer of 1 to 30.) R ^{101 to} R ¹⁰³ may be the same as or different from each other, and R ¹⁰⁴ has 1 to 6 carbon atoms which are branched or unbranched. Represents an alkylene group of

(In the formulas (2) and (3), R ²⁰¹ is hydrogen, halogen, branched or unbranched alkyl group having 1 to 30 carbon atoms, branched or unbranched alkenyl group having 2 to 30 carbon atoms, branched or unbranched. Or an alkyl group substituted with a hydroxyl group or a carboxyl group, and R ²⁰² represents a branched or unbranched C 1-30 alkylene group, branched or It represents an unbranched C2-C30 alkenylene group or a branched or unbranched C2-C30 alkynylene group, and R ²⁰¹ and R ²⁰² may form a ring structure.) The pneumatic tire produced using the rubber composition in any one of Claims 1-3 .