JP6835400B2 - Rubber composition and tires - Google Patents

Description

The present invention relates to rubber compositions and tires.

There is an increasing demand for fuel efficiency in automobiles in connection with the movement of global carbon dioxide emission regulation accompanying the growing interest in environmental issues. In order to meet such demands, reduction of rolling resistance is also required for tire performance.

As a method for reducing the rolling resistance of a tire, it is known as a general method to use a rubber composition having low heat generation. Specifically, for example, improving the dispersibility of a filler (particularly silica). Is being done. For the dispersion of silica, a method using a modified polymer is generally known (see, for example, Patent Documents 1 and 2). Further, in order to further enhance the silica dispersibility, it has been studied to use a multi-modified polymer in which a plurality of molecules (two or more molecules) of a modifying agent are introduced per molecule of the polymer as the modified polymer (see, for example, Patent Document 3). ).

International Publication No. 2003/02929 Pamphlet Japanese Unexamined Patent Publication No. 10-156440 Japanese Unexamined Patent Publication No. 2012-214711

However, when a modified polymer having a modified functional group at one end or both ends as in Patent Documents 1 and 2 is used, the viscosity of the unvulcanized rubber may increase and the workability of the rubber composition may decrease. Further, when the multi-modified polymer described in Patent Document 3 is simply blended into the rubber composition, the smoothness of the rubber composition may be lowered, the kneaded skin may be deteriorated, and the workability of the rubber composition may be deteriorated. It was.

INDUSTRIAL APPLICABILITY The present invention has a rubber composition having good workability, excellent wear resistance when applied to a tire, and further excellent in low heat generation, and a rubber composition having excellent wear resistance and low heat generation. The challenge is to provide excellent tires.

<1> A rubber component containing a diene polymer (A) having three or more modifier residues having an alkoxysilyl group in the main chain per molecule, and the like.
Silica (B) and
It is a rubber composition containing a silane coupling agent (C) represented by the following general formula (I).

In the formula, R ¹ is R ⁶ O-, R ⁶ C (= O) O-, R ⁶ R ⁷ C = NO-, R ⁶ R ⁷ NO-, R ⁶ R ⁷ N- and-(OSiR ⁶ R). ⁷ ) It is any one selected from the group consisting of _m (OSiR ⁵ R ⁶ R ^{7) and has 1 to 18 carbon atoms.} However, R ⁶ and R ⁷ are each independently selected from the group consisting of an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group and an aryl group, and have 1 to 1 carbon atoms. It is 18. m is 1 to 4.
R ² is any one selected from the group consisting of a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, an alkenyl group, a cycloalkenyl group and an aryl group.
R ³ is − [O (R ⁸ O) _p ] _0.5 − groups. However, R ⁸ is any one selected from the group consisting of an alkylene group and a cycloalkylene group, and has 1 to 18 carbon atoms. p is 1 to 4).
x, y, and z satisfy x + y + 2z = 3, 0 ≦ x ≦ 3, 0 ≦ y ≦ 2, and 0 ≦ z ≦ 1.
R ⁴ is any one selected from the group consisting of an alkylene group, a cycloalkylene group, a cycloalkylalkylene group, an alkenylene group, an arylene group and an aralkylene group, and has 1 to 18 carbon atoms.
R ⁵ is any one selected from the group consisting of an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group and an aralkyl group, and has 1 to 18 carbon atoms.
_{^{R 1, R 2, R 6}} , if ^{R 7,} which and ^{R 8} are a ^{plurality, _{R 1, R 2, R 6}} , ^{R 7,} and ^{R 8} each independently be different even in the same Good.

<2> The rubber composition according to <1>, wherein the diene-based polymer (A) has a monomer structure of the diene-based polymer between at least one of the modifier residues.

<3> The rubber composition according to <2>, wherein the diene-based polymer (A) has a monomer structure of the diene-based polymer between all the modifier residues.

<4> The rubber composition according to any one of <1> to <3>, wherein the denaturant residue further has at least one selected from the group consisting of a nitrogen atom and an oxygen atom. is there.

<5> The diene-based polymer (A) is a homopolymer composed of diene-based monomer units, or a diene-based monomer unit of 60% by mass or more and less than 100% by mass, and more than 0% by mass and 40% by mass. The rubber composition according to any one of <1> to <4>, which is a copolymer having a% or less aromatic vinyl compound unit.

<6> The rubber composition according to <5>, wherein the diene-based monomer unit is a 1,3-butadiene unit.

<7> The rubber composition according to <5> or <6>, wherein the aromatic vinyl compound unit is a styrene unit.

<8> The rubber composition according to any one of <1> to <7>, wherein the content of the diene polymer (A) in the rubber component is 10% by mass or more.

<9> Any of <1> to <8>, wherein the diene polymer (A) has three or more of the modifier residues only in the range from the terminal to 1/4 of the total chain length of the main chain. The rubber composition according to one.

<10> The rubber composition according to any one of <1> to <9>, wherein the content of the silica (B) is 60 to 250 parts by mass with respect to 100 parts by mass of the rubber component.

<11> Any one of <1> to <10> in which the content of the silane coupling agent (C) is 1 to 20 parts by mass with respect to 100 parts by mass of the silica (B) content. The rubber composition according to.

<12> A tire using the rubber composition according to any one of <1> to <11> as a tread member.

According to the present invention, a rubber composition having good workability, excellent wear resistance when applied to a tire, and excellent low heat generation can be obtained, and wear resistance and low heat generation. It is possible to provide a tire having excellent properties.

<Rubber composition>
The rubber composition of the present invention generally contains a rubber component containing a diene polymer (A) having three or more modifier residues having an alkoxysilyl group in the main chain per molecule, silica (B), and the like. Includes a silane coupling agent (C) represented by the formula (I) [R ¹ _x R ² _y R ³ _z Si-R ^4- S-CO-R ^5].
The details of the general formula (I) will be described later.
The rubber composition of the present invention may further contain sulfur, a vulcanization accelerator, and the like.
In the present invention, unless otherwise specified, the "rubber composition" refers to an unvulcanized rubber composition.

As described above, when a modified polymer having a modified functional group at one end or both ends of a conventionally used polymer is used together with silica, the viscosity of unvulcanized rubber is increased and the workability of the rubber composition is lowered. .. Further, by using a multi-modified polymer in which a plurality of modifiers are introduced per molecule of the polymer, higher silica dispersibility can be obtained. However, when the multi-modified polymer is used together with the silane coupling agent described in Patent Document 3 (for example, Si69 manufactured by Ebonic Degussa; bis- [γ- (triethoxysilyl) -propyl] -tetrasulfide). , The smoothness of the rubber composition was lowered, the kneaded skin was deteriorated, and the workability of the rubber composition was deteriorated.

On the other hand, as the multi-modified polymer, a diene polymer (A) having three or more modifying agent residues having an alkoxysilyl group in the main chain per molecule is used, and the general formula is used as a silane coupling agent. By using the silane coupling agent (C) represented by (I), the reason is not clear, but the rubber composition has improved workability and wear resistance when the rubber composition is applied to the tire. It is possible to obtain a tire having excellent properties and also excellent low heat generation.
By containing the silane coupling agent (C) represented by the general formula (I) in the rubber composition, the low heat generation property can be improved to some extent, but by using the diene polymer (A) in combination, , Higher heat generation tires can be obtained.
Hereinafter, the rubber composition and the tire of the present invention will be described in detail.
First, the rubber component will be described.

[Rubber component]
The rubber composition of the present invention contains a rubber component containing a diene polymer (A) having three or more modifier residues having an alkoxysilyl group in the main chain per molecule.
The rubber component may further contain natural rubber and the like in addition to the diene-based polymer (A).

[Diene polymer (A)]
The diene polymer (A) has three or more denaturant residues having an alkoxysilyl group in the main chain per molecule.
The method for producing the diene polymer (A) will be described later, but the diene polymer (A) has a molecular structure in which three or more molecules of a modifier are introduced per molecule of the diene polymer (A), and the modifier It has the derived molecular chain (modifier residue) in the main chain of the diene polymer (A). The diene-based polymer (A) has three or more modifier residues, which are molecular chains derived from the modifier, in the main chain of the diene-based polymer (A). The main chain of the diene polymer (A) is a molecular chain having a diene monomer unit, and is the longest molecular chain among the molecular chains of the diene polymer (A).

The alkoxysilyl group contained in the modifier residue is a modified functional group capable of interacting with silica (B), and forms a covalent bond between the alkoxysilyl group and the silica surface, or is covalent. It can form intermolecular forces that are weaker than bonds. The intermolecular force refers to an electromagnetic force acting between molecules such as an ion-dipole interaction, a dipole-dipole interaction, a hydrogen bond, and a van der Waals force.
In the present invention, the modifying agent residue contains at least an alkoxysilyl group as a modifying functional group, and may further have another modifying functional group.
The modifier residue preferably has any one or more selected from the group consisting of nitrogen atoms and oxygen atoms having a high affinity for silica, and other modifying functional groups include a nitrogen-containing functional group and an oxygen-containing functional group. The group is mentioned. Further, the modifier residue may further have a silicon-containing functional group other than the alkoxysilyl group.

Here, the diene-based polymer (A) may be a modified diene copolymer or a modified diene homopolymer. Among them, the diene-based polymer (A) is a homopolymer of a diene-based monomer unit or a diene-based single polymer of 60% by mass or more and less than 100% by mass from the viewpoint of improving low heat generation and abrasion resistance of the tire. A copolymer having a weight unit and an aromatic vinyl compound unit of more than 0% by mass and 40% by mass or less is preferable.
The homopolymer of the diene-based monomer unit is formed by homopolymerizing the diene-based monomer. Further, the copolymer having a diene-based monomer unit of 60% by mass or more and less than 100% by mass and an aromatic vinyl compound unit of more than 0% by mass and 40% by mass or less is 60% by mass or more and less than 100% by mass. The diene-based monomer of No. 1 is copolymerized with an aromatic vinyl compound of more than 0% by mass and 40% by mass or less.
The diene-based polymer (A) is a copolymer having a diene-based monomer unit of more than 65% by mass and less than 90% by mass and an aromatic vinyl compound unit of 10% by mass or more and 35% by mass or less. Is preferable.

Examples of the diene-based monomer constituting the main chain of the diene-based polymer (A) include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, and 2-phenyl-1,3-. Conjugated diene compounds such as butadiene and 1,3-hexadiene can be mentioned.
Among these, the diene-based monomer is preferably 1,3-butadiene. That is, the diene-based monomer unit is preferably 1,3-butadiene unit.
These conjugated diene compounds may be used alone or in combination of two or more.

On the other hand, examples of the aromatic vinyl compound as a monomer include styrene, α-methylstyrene, 1-vinylnaphthalene, 3-vinyltoluene, ethylvinylbenzene, divinylbenzene, 4-cyclohexylstyrene, and 2,4,6-trimethyl. Examples include styrene.
Among these, styrene is preferable as the aromatic vinyl compound. That is, the aromatic vinyl compound unit is preferably a styrene unit.
These aromatic vinyl compounds may be used alone or in combination of two or more.

The denaturing agent residue may be present evenly on the main chain of the diene polymer (A) regardless of its position, for example, as long as it is on the main chain of the diene polymer (A). It may be present at the end of the main chain (one end or both ends), or may be present at the center of the main chain.
Above all, from the viewpoint of enhancing the dispersibility of silica (B) in the rubber composition and enhancing the wear resistance and low heat generation of the tire, the diene polymer (A) is the main chain of the diene polymer (A). It is preferable to have the modifier residue only in the range from the end of the chain to 1/4 of the total chain length of the main chain (the range of 25% from the end). That is, the diene polymer (A) preferably has three or more denaturant residues only in the range from the end of the main chain to 1/4 of the total chain length of the main chain.
When the modifier residue is located in the range from the end of the main chain of the diene polymer (A) to 1/4 of the total chain length of the main chain, it is easier to suppress the aggregation of silica (B).

The end of the main chain of the diene polymer (A) means one end of the main chain, the other end, or both ends.
Therefore, the position of the modifier residue may be in the range from one end of the main chain of the diene polymer (A) to 1/4 of the total chain length of the main chain, or from the other end to the full chain of the main chain. It may be in the range of 1/4 of the length, or may be in the range of 1/4 of the total length of the main chain from both ends.

Further, from the viewpoint of efficiently obtaining the performance by modification and further suppressing the aggregation of silica (B), the three or more modifier residues are from one end of the main chain of the diene polymer (A) to the main chain. More preferably, it is present only in the range of 1/4 of the total chain length of. In other words, it is more preferable that there is no denaturant residue in a portion other than the range from one end of the main chain to 1/4 of the total length of the main chain. In other words, the range from one end of the main chain of the diene polymer (A) to the total chain length of the main chain is 3/4 to 4/4, that is, the total chain length of the main chain from the other end of the main chain. It is more preferable that there is no denaturing agent residue in the portion in the range of 1/4 of the above.

The diene-based polymer (A) has three or more denaturant residues per molecule of the diene-based polymer (A) in the main chain. It is preferable to have a monomer structure of the diene polymer between the denaturant residue and the denaturant residue (between the denaturant residue). By having the monomer structure of the diene polymer between the modifier residues, the aggregate of silica can be efficiently broken.
Here, the "monomer of the diene-based polymer" means a diene-based monomer if the diene-based polymer is a homopolymer of the diene-based monomer, and the diene-based polymer is a diene-based monomer. In the case of a copolymer of a body and another monomer (for example, a diene-based monomer or the other monomer, or a diene-based monomer and the other monomer.

"A state having a monomer structure of a diene polymer between modifier residues" means a monomer constituting a diene polymer between the modifier residue and the modifier residue (for example, When the diene polymer is polybutadiene, it is 1,3-butadiene, and when it is a styrene-butadiene copolymer, it is styrene or 1,3-butadiene or styrene and 1,3-butadiene). It means that the modifier residues are not directly bound to each other.
Further, the "monomer structure of the diene polymer" has two double bonds derived from the monomer of the diene polymer on the main chain of the diene polymer (A). On the other hand, the "diene-based monomer unit" derived from the diene-based monomer used to obtain the diene-based polymer (A) has one double bond on the main chain of the diene-based polymer (A). Have one.

By adopting a structure in which the modifier residues do not directly bond with each other, the affinity with silica can be further improved, so that the low heat generation property and the wear resistance of the tire can be further improved.
Further, from the same viewpoint, the diene-based polymer (A) preferably has a diene-based polymer structure between at least one modifier residue, and has a diene-based weight between all the modifier residues. It is more preferable to have a coalesced monomer structure. That is, it is more preferable that all the denaturant residues of the diene polymer (A) do not directly bind to each other with the denaturant residues.

(I) It has a structure of a diene polymer between the modifier residues, and (ii) the modifier residue is 1 of the total chain length from the end of the main chain of the diene polymer (A) to the main chain. When it is located in the range of / 4, the silica (B) and the alkoxysilyl group in the rubber component are present as compared with the case where the conventional diene-based polymer having the characteristics of (i) and (ii) individually is used. Is easy to react efficiently, and the dispersibility of silica (B) can be further enhanced. As a result, the low heat generation and body wear of the tire can be further improved.

The polymerization method for obtaining the diene-based polymer (A) may be any of anionic polymerization, coordination polymerization, and emulsion polymerization. The modifier is not particularly limited as long as the modifier residue can have an alkoxysilyl group when the modifier residue is formed in the diene polymer (A), and is anionic polymerization or coordination polymerization. It may be a modifier that reacts with the polymerization active terminal of the above, or it may have an amide moiety of a lithium amide compound used as a polymerization initiator. Further, in emulsion polymerization, the modifier may be copolymerized as a monomer.

The molecular weight of the diene polymer (A) is not particularly limited, but by setting the peak molecular weight to 50,000 or more, it is easy to obtain a tire with better wear resistance, and the tire is provided with fracture resistance. easy. By setting the peak molecular weight of the diene polymer (A) to 700,000 or less, the workability of the rubber composition becomes better. Further, from the viewpoint of achieving both high wear resistance of the tire and better workability of the rubber composition, it is desirable that the peak molecular weight of the diene polymer (A) is 100,000 to 350,000.
The peak molecular weight of the diene polymer (A) is a polystyrene-equivalent peak molecular weight (Mp) measured by gel permeation chromatography (GPC).

The content of the diene polymer (A) in the rubber component is preferably 10% by mass or more. When the content of the diene polymer (A) in the rubber component is 10% by mass or more, the effect of improving the dispersibility of the silica (B) can be enhanced, and the rubber composition has low heat generation and low heat generation. The effect of improving wear resistance can be enhanced. The content of the diene polymer (A) in the rubber component is more preferably 20% by mass or more, and further preferably 30% by mass or more.
From the same viewpoint, the content of the diene polymer (A) in the rubber composition of the present invention is preferably 10% by mass or more, more preferably 12% by mass or more.

Here, a modifying agent used for modification when obtaining the diene-based polymer (A) will be described. The modifier for introducing the modifier residue having an alkoxysilyl group into the diene polymer (A) is a modifier having at least an alkoxysilyl group. The modifier may further have a functional group interacting with silica (B), and together with the modifier having an alkoxysilyl group, has an interaction with silica (B). A modifier having a functional group may be used. The modifying agent having a functional group having an interaction with silica (B) is preferably a modifying agent having any one or more selected from the group consisting of nitrogen atoms and oxygen atoms. The denaturant containing a nitrogen atom and an oxygen atom has a high affinity for silica (B).
Further, the modifier may further have a silicon-containing functional group other than the alkoxysilyl group, and a modifier having a silicon-containing functional group other than the alkoxysilyl group may be used together with the modifier having an alkoxysilyl group. You may.

The modifier having an alkoxysilyl group is preferably an alkoxysilane compound. Although the alkoxysilane is not particularly limited, it is preferably an alkoxysilane compound represented by the following general formula (II) from the viewpoint of enhancing the affinity for silica (B).

In the general formula (II), R ¹¹ and R ¹² each independently represent a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. However, ^{at least one of R 12 represents} a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms.
a is an integer of 0 to 2, if the OR ¹² there are a plurality, the plurality of OR ¹² may be the same or different from each other, in the molecule does not include active proton.

Here, specific examples of the alkoxysilane compound represented by the general formula (II) include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, and the like. Tetraisobutoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, Ethyltripropoxysilane, ethyltriisopropoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltripropoxysilane, propyltriisopropoxysilane, butyltrimethoxysilane, butyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxy Examples thereof include silane, dimethyldimethoxysilane, methylphenyldimethoxysilane, dimethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and divinyldiethoxysilane.
Among these, tetraethoxysilane, methyltriethoxysilane and dimethyldiethoxysilane are suitable as the alkoxysilane compound represented by the general formula (II). These may be used individually by 1 type, and may be used in combination of 2 or more type.

Further, from the viewpoint of having a high affinity for silica (B), the denaturing agent may be a hydrocarbyloxysilane compound. The hydrocarbyloxysilane compound is preferably a hydrocarbyloxysilane compound represented by the following general formula (III).

In the general formula (III), n1 + n2 + n3 + n4 = 4 (where n2 is an integer of 1 to 4, and n1, n3 and n4 are integers of 0 to 3).
A ¹ represents a saturated cyclic tertiary amine compound residue, an unsaturated cyclic tertiary amine compound residue, a ketimine residue, a nitrile group, and a (thio) isocyanato group (isocyanato group or thioisocyanate group. Hereinafter, (Similar), (thio) epoxy group, isocyanuric acid trihydrocarbyl ester group, dihydrocarbyl carbonate group, pyridine group, (thio) ketone group, (thio) aldehyde group, amide group, (thio) carboxylic acid ester group, (thio) ) At least one selected from the group consisting of a metal salt of a carboxylic acid ester, a carboxylic acid anhydride residue, a carboxylic acid halogen compound residue, and a primary or secondary amino group or mercapto group having a hydrolyzable group. It is a functional group of the species. When n4 is 2 or more, A ¹ may be the same or different. A ¹ may be a divalent group that combines with Si to form a cyclic structure.
R ²¹ is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and may be the same when n1 is 2 or more. It may be different.
R ²³ is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, or a halogen atom (fluorine atom, chlorine atom, bromine atom, It is an iodine atom), and when n3 is 2 or more, it may be the same or different.
R ²² is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. The aliphatic or alicyclic hydrocarbon group and the aromatic hydrocarbon group may all contain one or both of a nitrogen atom and a silicon atom. When n2 is 2 or more, R ²² may be the same or different from each other, or may be bonded to each other to form a ring.
R ²⁴ is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and may be the same when n4 is 2 or more. It may be different.
However, the hydrocarbyloxysilane compound represented by the general formula (III) has at least one alkoxysilyl group. That is, when n2 is 0, ^{at least one of R 21} is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, and when n2 is 1 or more, R ²¹ and R ^22. At least one of them is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms.

As the hydrolyzable group in the primary or secondary amino group having a hydrolyzable group or the mercapto group having a hydrolyzable group, a trimethylsilyl group or a tert-butyldimethylsilyl group is preferable, and a trimethylsilyl group is particularly preferable.
In the present invention, the "monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms" is defined as "a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms or 3 to 20 carbon atoms". It means "monovalent alicyclic hydrocarbon group". The same applies to the case of divalent hydrocarbon groups.

Further, the hydrocarbyloxysilane compound represented by the general formula (III) is preferably a hydrocarbyloxysilane compound represented by the following general formula (IV).

In the general formula (IV), p1 + p2 + p3 = 2 (where p2 is an integer of 1 to 2 and p1 and p3 are integers of 0 to 1).
A ² is NRa (Ra is a monovalent hydrocarbon group, a hydrolyzable group or a nitrogen-containing organic group. As the hydrolyzable group, a trimethylsilyl group or a tert-butyldimethylsilyl group is preferable, and a trimethylsilyl group is particularly preferable. It is preferable), or it is a sulfur atom.
R ²⁵ is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ²⁷ is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, or a halogen atom (fluorine atom, chlorine atom, bromine atom, Iodine atom).
R ²⁶ is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, or a nitrogen-containing organic group. The aliphatic or alicyclic hydrocarbon group and the aromatic hydrocarbon group may all contain one or both of a nitrogen atom and a silicon atom. Further, the nitrogen-containing organic group may further contain a silicon atom. If p2 is 2, R ²⁶ is different from the same or each other, or may be bonded to each other to form a ring.
R ²⁸ is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
However, the hydrocarbyloxysilane compound represented by the general formula (IV) has at least one alkoxysilyl group. That is, when p2 is 0, ^{at least one of R 25} is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, and when p2 is 1 or more, R ²⁵ and R ^26. At least one of them is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms.

Further, the hydrocarbyloxysilane compound represented by the general formula (III) is more preferably a hydrocarbyloxysilane compound represented by the following general formula (V) or (VI).

In the general formula (V), q1 + q2 = 3 (where q1 is an integer of 0 to 2 and q2 is an integer of 1 to 3).
R ³¹ is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ³² and R ³³ are independently hydrolyzable groups, monovalent aliphatic or alicyclic hydrocarbon groups having 1 to 20 carbon atoms, or monovalent aromatic hydrocarbon groups having 6 to 18 carbon atoms, respectively. ..
R ³⁴ is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and is the same or different when q1 is 2. You may.
R ³⁵ is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and when q2 is 2 or more, it is the same or different. You may.
However, the hydrocarbyloxysilane compound represented by the general formula (V) has at least one alkoxysilyl group. That is, ^{at least one of R 35} is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms.

In the general formula (VI), r1 + r2 = 3 (where r1 is an integer of 1 to 3 and r2 is an integer of 0 to 2).
R ³⁶ is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ³⁷ is a dimethylaminomethyl group, a dimethylaminoethyl group, a diethylaminomethyl group, a diethylaminoethyl group, a methylsilyl (methyl) aminomethyl group, a methylsilyl (methyl) aminoethyl group, a methylsilyl (ethyl) aminomethyl group, a methylsilyl (ethyl) amino. Ethyl group, dimethylsilylaminomethyl group, dimethylsilylaminoethyl group, monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. , R1 may be the same or different when r1 is 2 or more.
R ³⁸ is a hydrocarbyloxy group having 1 to 20 carbon atoms, a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and r2. When is 2, it may be the same or different.
However, the hydrocarbyloxysilane compound represented by the general formula (VI) has at least one alkoxysilyl group. That is, ^{at least one of R 37} is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms.

The denaturing agent is preferably a hydrocarbyloxysilane compound having two or more nitrogen atoms represented by the following general formula (VII) or (VIII).

In the general formula (VII), TMS is a trimethylsilyl group, R ⁴⁰ is a trimethylsilyl group, an aliphatic monovalent C1-20 or alicyclic hydrocarbon group or aromatic monovalent C6-18 It is a hydrocarbon group.
R ⁴¹ is a hydrocarbyloxy group having 1 to 20 carbon atoms, a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ⁴² is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
However, the hydrocarbyloxysilane compound represented by the general formula (VII) has at least one alkoxysilyl group. That is, ^{at least one of R 41} is a hydrocarbyloxy group having 1 to 20 carbon atoms.

In the general formula (VIII), TMS is a trimethylsilyl ^{group, R 43} and ^{R 44} each independently second divalent aliphatic or alicyclic hydrocarbon group or a C6-18 having 1 to 20 carbon atoms It is a valent aromatic hydrocarbon group.
R ⁴⁵ is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and a plurality of R ^45s are the same but different. May be good.
However, the hydrocarbyloxysilane compound represented by the general formula (VIII) has at least one alkoxysilyl group. That is, ^{at least one of R 45} is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms.

Further, the hydrocarbyloxysilane compound represented by the general formula (III) is preferably a hydrocarbyloxysilane compound represented by the following general formula (IX).

In the general formula (IX), r1 + r2 = 3 (where r1 is an integer of 0 to 2 and r2 is an integer of 1 to 3), and TMS is a trimethylsilyl group.
R ⁴⁶ is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ⁴⁷ and R ⁴⁸ are independently monovalent aliphatic or alicyclic hydrocarbon groups having 1 to 20 carbon atoms or monovalent aromatic hydrocarbon groups having 6 to 18 carbon atoms. The plurality of R ^47s or R ^48s may be the same or different.
However, the hydrocarbyloxysilane compound represented by the general formula (IX) has at least one alkoxysilyl group. That is, ^{at least one of R 48} is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms.

Further, the hydrocarbyloxysilane compound represented by the general formula (IV) is preferably a compound represented by the following general formula (X).

In the general formula (X), X is a halogen atom, and R ⁴⁹ is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms. Is.
R ⁵⁰ and R ⁵¹ are independently hydrolyzable groups, monovalent aliphatic or alicyclic hydrocarbon groups having 1 to 20 carbon atoms, or monovalent aromatic hydrocarbon groups having 6 to 18 carbon atoms, respectively. .. R ⁵⁰ and R ⁵¹ may be bonded to each other to form a divalent organic group.
R ⁵² and R ⁵³ are independently halogen atoms, hydrocarbyloxy groups, monovalent aliphatic or alicyclic hydrocarbon groups having 1 to 20 carbon atoms, or monovalent aromatic hydrocarbon groups having 6 to 18 carbon atoms, respectively. Is.
However, the hydrocarbyloxysilane compound represented by the general formula (X) has at least one alkoxysilyl group. That is, ^{at least one of R 52} and R ⁵³ is a hydrocarbyloxy group.
R ⁵⁰ and R ⁵¹ are preferably hydrolyzable groups, and as the hydrolyzable group, a trimethylsilyl group or a tert-butyldimethylsilyl group is preferable, and a trimethylsilyl group is particularly preferable.

In the hydrocarbyloxysilane compounds represented by the above general formulas (III) to (X), when the diene polymer (A) is a modified conjugated diene polymer, the modified conjugated diene polymer is subjected to anionic polymerization. It is preferably used when it is manufactured.
Further, the hydrocarbyloxysilane compound represented by the general formulas (III) to (X) is preferably an alkoxysilane compound.

Specific examples of suitable modifiers for modifying the diene polymer (A) by anionic polymerization include 3,4-bis (trimethylsilyloxy) -1-vinylbenzene and 3,4-bis (trimethylsilyloxy). ) Benzaldehyde, and at least one compound selected from the group consisting of 3,4-bis (tert-butyldimethylsilyloxy) benzaldehyde.
In addition, together with these compounds having an alkoxysilyl group, at least one compound selected from the group consisting of 2-cyanopyridine, 1,3-dimethyl-2-imidazolidinone, and 1-methyl-2-pyrrolidone can be used. You may use it.

As another modifier that can be used with a modifier having an alkoxysilyl group, an amide moiety of a lithium amide compound used as a polymerization initiator in anionic polymerization is also suitable.
Examples of the lithium amide compound include lithium hexamethyleneimide, lithium pyrrolidide, lithium piperidide, lithium heptamethyleneimide, lithium dodecamethyleneimide, lithium dimethylamide, lithium diethylamide, lithium dibutylamide, lithium dipropylamide, and lithium diheptylamide. A group consisting of lithium dihexyl amide, lithium dioctyl amide, lithium di-2-ethyl hexyl amide, lithium didecyl amide, lithium-N-methylpiberazine, lithium ethyl propyl amide, lithium ethyl butyl amide, lithium ethyl benzyl amide, and lithium methyl phenethyl amide. Included are at least one compound that is more selected.
The amide moiety of the lithium amide compound is considered as follows. For example, the modifier that becomes the amide moiety of lithium hexamethyleneimide is hexamethyleneimine, the modifier that becomes the amide moiety of lithium pyrrolidine is pyrrolidine, and the modifier that becomes the amide moiety of lithium piperidine is piperidine. is there.

Examples of a suitable modifier for modifying the diene polymer (A) by coordination polymerization include 3,4-ditrimethylsilyloxybenzaldehyde, and 2-cyanopyridine may be used in combination.

Examples of a suitable modifier for modifying the diene polymer (A) by emulsion polymerization include 3,4-ditrimethylsilyloxybenzaldehyde, and 4-hexamethyleneiminoalkylstyrene may be used in combination. The denaturing agent preferably used in these emulsion polymerizations is preferably copolymerized as a monomer during emulsion polymerization.

The diene polymer (A) preferably has a glass transition point (Tg) of 0 ° C. or lower as measured by a differential scanning calorimeter (DSC). Since the glass transition point of the diene polymer (A) is 0 ° C. or lower, the rubber properties at low temperatures are not easily impaired.

[Other rubber components]
In the rubber composition of the present invention, in addition to the diene-based polymer (A), the rubber component further includes natural rubber (NR), styrene-butadiene copolymer (SBR), polybutadiene rubber (BR), and polyisoprene rubber ( It can contain other rubber components such as IR), butyl rubber (IIR), and ethylene-propylene copolymer. As the other rubber component, at least one selected from the group consisting of natural rubber, polyisoprene rubber, polybutadiene rubber, and styrene-butadiene copolymer is preferable. These other rubber components may be used alone or in combination of two or more.

[Method for producing diene polymer (A)]
Regarding the method for producing the diene-based polymer (A), a diene-based monomer can be used to form a molecular structure having three or more modifier residues having an alkoxysilyl group in the main chain per molecule. The manufacturing method is not particularly limited.
As described above, the denaturant residue is evenly present on the main chain of the diene polymer (A) regardless of its position, for example, if it is on the main chain of the diene polymer (A). It may be present at the end of the main chain (one end or both ends), or may be present at the center of the main chain.

For example, when the modifier residues are evenly present on the main chain of the diene polymer (A), the diene monomer can be copolymerized with the monomer component of the diene polymer. Achieved by simultaneously adding a compound having a site capable of introducing an alkoxysilyl group by chemically reacting with an alkoxysilyl group-containing compound before starting polymerization, and then adding a polymerization initiator to start polymerization. Will be done.

In the present invention, from the viewpoint of further suppressing the aggregation of silica (B), the modifier residue has (i) a monomeric structure of a diene polymer between the modifier residues, and further (ii). ) It is preferable that the modifier residue is located in the range from the end of the main chain of the diene polymer (A) to 1/4 of the total chain length of the main chain. As one of the production methods for producing the diene-based polymer (A) having the characteristics of (i) and (ii), for example, the molecule of the diene-based polymer (A) having no alkoxysilyl group. _{A step (a 3/4} ) of forming a chain [a range of 3/4 of the total chain length of the main chain from the end of the main chain of the diene polymer (A)], and an alkoxysilyl group and a diene polymer (a 3/4). _{The step (a 1/4} ) of forming a molecular chain composed of the monomer structure of A) [a range of 1/4 of the total chain length of the main chain from the end of the main chain of the diene polymer (A)] is performed. By passing through, a diene polymer (A) having the characteristics of (i) and (ii) can be obtained.
Either step (a _3/4 ) or step (a _1/4 ) may be performed first, but _{the step (a 3/4} ) may be performed prior to the step (a _1/4). preferable. By performing the step (a _3/4 ) first, it is possible to prevent the unreacted alkoxysilyl group and the monomer of the diene polymer (A) from reacting in the later step, and the diene polymer (A). ) Can suppress the formation of modifier residues in a range other than the range of 1/4 of the total chain length of the main chain.

When the step (a _1/4 ) is performed first, after confirming that the polymerization conversion rate is 100% each time the _{step (a 1/4 ) is completed, the step (a 3/4) is performed.} ) Is preferable. By performing the next step after confirming that the polymerization conversion rate is 100%, a range other than the range from the end of the main chain of the diene polymer (A) to 1/4 of the total chain length of the main chain In addition, the formation of denaturant residues can be suppressed.

Here, for the formation of the molecular chain composed of the alkoxysilyl group and the monomer structure of the diene polymer, for example, the following methods (1) to (4) can be mentioned.
(1) A method in which a monomer component of a diene-based polymer and a modifier capable of copolymerizing with the monomer component and having an alkoxysilyl group are alternately added.
(2) A method in which a monomer component of a diene-based polymer and a modifier that is copolymerizable with the monomer component and has an alkoxysilyl group are simultaneously added.
(3) A site in which a monomer component of a diene polymer can be copolymerized with the monomer component and an alkoxysilyl group can be introduced by chemically reacting with an alkoxysilyl group-containing compound. A method in which the compounds to be charged are alternately added.
(4) A site in which the monomer component of the diene polymer can be copolymerized with the monomer component and the alkoxysilyl group can be introduced by chemically reacting with the alkoxysilyl group-containing compound. A method of simultaneously adding a compound having a compound.

Among the above (1) to (4), all the modifier residues of the diene polymer have a monomer structure between all the modifier residues (that is, all the modifier residues of the diene polymer (A)). The method (1) or (3) is preferable as the method for producing the diene polymer (A) from the viewpoint of more reliably forming a structure (which does not directly bind to each other) with the modifier residue. Further, from the viewpoint of shortening the production time and increasing the productivity, the method (2) or (4) is preferable as the method for producing the diene-based polymer (A).
Examples of the compound having a site capable of copolymerizing with the monomer component of the diene polymer and introducing an alkoxysilyl group by chemically reacting with the alkoxysilyl group-containing compound include, for example, 4 -Methylstyrene and the like can be mentioned.

[Silica (B)]
The rubber composition of the present invention contains silica (B).
When the rubber composition contains silica (B), the reinforcing effect of the rubber composition can be enhanced and the wear resistance of the tire can be improved.
The content of silica (B) is preferably 60 to 250 parts by mass with respect to 100 parts by mass of the rubber component. When the content of silica (B) is 60 to 250 parts by mass or more, the wear resistance of the tire can be further improved, and when it is 250 parts by mass or less, the workability of the rubber composition is impaired. Hateful. The content of silica (B) is more preferably 60 to 150 parts by mass, further preferably 60 to 120 parts by mass, and 60 to 100 parts by mass with respect to 100 parts by mass of the rubber component. Is particularly preferable.

The type of silica (B) is not particularly limited, and can be used depending on the application, from general grade silica to special silica with surface treatment. For example, wet silica (hydrous silicic acid) and dry silica (dry silica) (Silica anhydride), calcium silicate, aluminum silicate and the like can be mentioned. These may be used alone or in combination of two or more.
Among the above, it is preferable to use wet silica as the silica (B) from the viewpoint of further improving the workability of the rubber composition and the wear resistance of the tire.

[Silane coupling agent (C)]
The rubber composition of the present invention contains a silane coupling agent (C) represented by the following general formula (I).
When the rubber composition contains the silane coupling agent (C), the workability of the rubber composition is enhanced, and the surface properties of the molded product obtained after kneading the rubber composition are excellent. Specifically, the surface of the molded body is smooth, cracks and embrittlement of the molded body can be suppressed. Further, when the rubber composition contains the silane coupling agent (C), the rubber composition of the present invention Tires obtained from objects are excellent not only in wear resistance but also in low heat generation. The silane coupling agent (C) had a function of suppressing the rolling resistance of the tire by using it with a conventional rubber or a conventional modified rubber, but it should be used together with the above-mentioned diene polymer (A). As a result, it was found that it is possible to realize even higher heat generation than before.
Hereinafter, the general formula (I) will be described.

In the formula, R ¹ is R ⁶ O-, R ⁶ C (= O) O-, R ⁶ R ⁷ C = NO-, R ⁶ R ⁷ NO-, R ⁶ R ⁷ N- and-(OSiR ⁶ R). ⁷ ) It is any one selected from the group consisting of _m (OSiR ⁵ R ⁶ R ^{7) and has 1 to 18 carbon atoms.} However, R ⁶ and R ⁷ are each independently selected from the group consisting of an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group and an aryl group, and have 1 to 1 carbon atoms. It is 18. m is 1 to 4.
R ² is any one selected from the group consisting of a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, an alkenyl group, a cycloalkenyl group and an aryl group.
R ³ is − [O (R ⁸ O) _p ] _0.5 − groups. However, R ⁸ is any one selected from the group consisting of an alkylene group and a cycloalkylene group, and has 1 to 18 carbon atoms. p is 1 to 4).
x, y, and z satisfy x + y + 2z = 3, 0 ≦ x ≦ 3, 0 ≦ y ≦ 2, and 0 ≦ z ≦ 1.
R ⁴ is any one selected from the group consisting of an alkylene group, a cycloalkylene group, a cycloalkylalkylene group, an alkenylene group, an arylene group and an aralkylene group, and has 1 to 18 carbon atoms.
R ⁵ is any one selected from the group consisting of an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group and an aralkyl group, and has 1 to 18 carbon atoms.
_{^{R 1, R 2, R 6}} , if ^{R 7,} which and ^{R 8} are a ^{plurality, _{R 1, R 2, R 6}} , ^{R 7,} and ^{R 8} each independently be different even in the same Good.

In the above R ^2, R ^5, R ⁶ and R ^7, the alkyl group may be linear or branched, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group. Further, the alkenyl group may be linear or branched, and examples of the alkenyl group include a vinyl group, an allyl group, a metanyl group and the like. Further, examples of the cycloalkyl group include a cyclohexyl group and an ethylcyclohexyl group, examples of the cycloalkenyl group include a cyclohexenyl group and an ethylcyclohexenyl group, and examples of the aryl group include a phenyl group and a tolyl group. Furthermore, in R ^5, the aralkyl group, phenethyl group.

In the above R ⁴ and R ^8, an alkylene group may be branched be linear, as it is the alkylene group include a methylene group, an ethylene group, a trimethylene group and a propylene group. Moreover, as a cycloalkylene group, a cyclohexylene group and the like can be mentioned. Furthermore, in R ^4, alkenylene group, as also well, the alkenylene group branched be linear, vinylene group, propenylene group and the like. Further, examples of the cycloalkylalkylene group include a cyclohexylmethylene group, examples of the arylene group include a phenylene group, and examples of the aralkylene group include a xylylene group.

Further, in R ³ above, the − [O (R ⁸ O) _m ] _0.5 − group is obtained by removing two hydrogen atoms of the hydroxyl group from the diol shown below. Here, as the diol, ethylene glycol, propylene glycol, neopentyl glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,3-butanediol, 2-methyl-2,4- Examples thereof include pentandiol, 1,4-butanediol, cyclohexanedimethanol, and pinacol. Among these, ethylene glycol, propylene glycol, neopentyl glycol, 1,3-propanediol, 2-methyl-1,3-propanediol. , 1,3-Butanediol, 2-methyl-2,4-pentanediol is preferred, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,3-butanediol, 2-methyl- 2,4-Pentanediol is more preferable.

The sulfur-containing silane compound of the general formula (I) can be synthesized by the method described in JP-A-2001-505225, and the trade name "NXTsilane" manufactured by GE Silicone Co., Ltd. and "3" manufactured by Momentive Co., Ltd. A commercially available product such as − (octanoylthio) -1-propyltriethoxysilane ”can also be used.
The content of the silane coupling agent (C) is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the silica (B) content. When the content of the silane coupling agent (C) is 1 part by mass or more with respect to 100 parts by mass of the silica (B) content, the workability of the rubber composition and the surface of the molded product of the rubber composition The properties can be made better, and the excellent low heat generation of the tire due to the synergistic effect with the diene polymer (A) can be further improved. When the content of the silane coupling agent (C) is 20 parts by mass or less with respect to 100 parts by mass of the silica (B) content, gelation of the rubber component is suppressed and the workability of the rubber composition is suppressed. Is hard to damage.
The content of the silane coupling agent (C) is more preferably 5 to 12 parts by mass with respect to 100 parts by mass of the silica (B) content.

[Carbon black (D)]
The rubber composition of the present invention preferably contains carbon black (D).
The carbon black (D) is not particularly limited, and for example, SRF, GPF, FEF, HAF, ISAF, SAF, etc., and a mixture thereof (for example, ISAF-HAF, etc.) are used, and the iodine adsorption amount (IA) is 60 mg. Carbon black having a dibutyl phthalate oil absorption (DBP) of 80 ml / 100 g or more is preferable. Of these, HAF, ISAF, SAF, and ISAF-HAF, which have excellent wear resistance, are more preferable.
The content of carbon black (D) is preferably 5 to 50 parts by mass and 10 to 30 parts by mass with respect to 100 parts by mass of the rubber component from the viewpoint of reinforcing property of the rubber composition and improvement of wear resistance of the tire. More preferably, it is by mass.

[Various components (E)]
The rubber composition of the present invention contains vulcanizing agents, vulcanization accelerators, antiaging agents, process oils, zinc oxide, scorch inhibitors, dispersion aids, stearic acid, etc., as long as the object of the present invention is not impaired. It can contain various components (E) usually used in the rubber industry.
Examples of the vulcanizing agent include sulfur, and the content of the vulcanizing agent is preferably 0.1 to 10.0 parts by mass as the sulfur content with respect to 100 parts by mass of the rubber component, and 0.5 to 5. 0 parts by mass is more preferable.

The vulcanization accelerator that can be used in the rubber composition of the present invention is not particularly limited, but is, for example, M (2-mercaptobenzothiazole), DM (dibenzothiazyldisulfide), CZ (N-cyclohexyl-2). -Benzothiazil sulfenamide), thiazole-based vulcanization accelerators such as NS (N-t-butyl-2-benzothiazyl sulfenamide), or guanidine-based vulcanization accelerators such as DPG (diphenylguanidine). Can be done. These vulcanization accelerators may be used alone or in combination of two or more.
The content of the vulcanization accelerator (the content of the total vulcanization accelerator when two or more kinds are used) is preferably 1 to 8 parts by mass and 2 to 6 parts by mass with respect to 100 parts by mass of the rubber component.
In addition, examples of the process oil used as the softening agent that can be used in the rubber composition of the present invention include paraffin-based, naphthenic-based, and aromatic-based. The content of the process oil is preferably 5 to 80 parts by mass, more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the rubber component. Within such a range, the low heat generation of the tire is unlikely to be impaired.

Examples of the antioxidant that can be used in the rubber composition of the present invention include 3C (N-isopropyl-N'-phenyl-p-phenylenediamine, 6C [N- (1,3-dimethylbutyl) -N'-phenyl- p-phenylenediamine], AW (6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline), high-temperature condensate of diphenylamine and acetone, etc. The content of the anti-aging agent is 0.1 to 6.0 parts by mass is preferable, and 0.3 to 5.0 parts by mass is more preferable with respect to 100 parts by mass of the rubber component.

<Tire>
The tire of the present invention is made by using the rubber composition of the present invention as a tread member, and has wear resistance and excellent low heat generation. In the case of a tire having a tread having a cap / base structure, the rubber composition of the present invention may be used for the cap rubber or the base rubber.
The tire of the present invention is manufactured by a usual method using the rubber composition of the present invention as a tread member. That is, the rubber component containing the diene polymer (A) described above, the silica (B), the silane coupling agent (C) represented by the general formula (I), and, if necessary, carbon black ( The rubber composition containing D) and various components (E) is processed into a tire tread at the unvulcanized stage, and is pasted and molded on a tire molding machine by a usual method to mold a raw tire. The raw tire is heated and pressurized in a vulcanizer to obtain a tire.

<Uses other than tires>
The rubber composition of the present invention can also be used for anti-vibration rubber, seismic isolation rubber, belts (conveyor belts), rubber crawlers, various hoses, etc., in addition to tire applications.

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these examples.

<Manufacturing of polymers A to H>
Polymers A (unmodified polymer) and polymers B to H (modified polymers) were produced according to the following procedure.

[Production of polymer A]
A cyclohexane solution of 1,3-butadiene and a cyclohexane solution of styrene were added to a dry, nitrogen-substituted 5 liter pressure vessel to make up 551 grams of 1,3-butadiene and 129 grams of styrene. Further, 2.62 mmol of 2,2-ditetrahydrofurylpropane was added to the pressure-resistant container, 5.23 mmol of n-butyllithium was further added as a polymerization initiator, and then polymerization was carried out at 50 ° C. for 1.5 hours. It was. The polymerization conversion rate at this time was almost 100%.
Then, 3 ml of a solution of 2,6-di-t-butyl-p-cresol (BHT) in 5% by mass of isopropanol was added to the polymerization reaction system to stop the reaction, and the reaction product was dried and unmodified according to a conventional method. Polymer A, which is a polymer, was obtained.

[Production of polymer B]
A cyclohexane solution of 1,3-butadiene and a cyclohexane solution of styrene were added to a dry, nitrogen-substituted 5 liter pressure vessel to make up 551 grams of 1,3-butadiene and 129 grams of styrene. Further, 2.62 mmol of 2,2-ditetrahydrofurylpropane was added to the pressure-resistant container, 5.23 mmol of n-butyllithium was further added as a polymerization initiator, and then polymerization was carried out at 50 ° C. for 1.5 hours. It was. The polymerization conversion rate at this time was almost 100%.
Subsequently, 5.23 mmol of N, N-bis (trimethylsilyl) -3-aminopropylmethyldimethoxysilane (structure below) was added as a denaturant 1 to the polymerization reaction system, and the mixture was reacted for 30 minutes. Then, 3 ml of a solution of 2,6-di-t-butyl-p-cresol (BHT) in 5% by mass of isopropanol was added to the polymerization reaction system to stop the reaction, and the reaction product was dried according to a conventional method to modify the weight. Polymer B, which is a coalescence, was obtained.

[Production of polymer C]
A cyclohexane solution of 1,3-butadiene and a cyclohexane solution of styrene were added to a dry, nitrogen-substituted 5 liter pressure vessel to make up 551 grams of 1,3-butadiene and 129 grams of styrene. Further, 2.62 mmol of 2,2-ditetrahydrofurylpropane was added to the pressure-resistant container, 5.23 mmol of n-butyllithium was further added as a polymerization initiator, and then polymerization was carried out at 50 ° C. for 1.5 hours. It was. The polymerization conversion rate at this time was almost 100%.
Subsequently, in the polymerization reaction system, as a denaturant 2, 5.23 mmol of N- [2-N', N'-bis (trimethylsilyl) aminoethyl] -N- (trimethylsilyl) -3-aminopropyltriethoxysilane ( The following structure) was added and reacted for 30 minutes. Then, 3 ml of a solution of 2,6-di-t-butyl-p-cresol (BHT) in 5% by mass of isopropanol was added to the polymerization reaction system to stop the reaction, and the reaction product was dried according to a conventional method to modify the weight. A coalesced polymer C was obtained.

[Production of polymer D]
A cyclohexane solution of 1,3-butadiene and a cyclohexane solution of styrene were added to a dry, nitrogen-substituted 5 liter pressure vessel to make up 551 grams of 1,3-butadiene and 129 grams of styrene. In addition, 15.69 mmol of 4-methylstyrene and 2.62 mmol of 2,2-ditetrahydrofurylpropane were added to the pressure-resistant container. Further, 5.23 mmol of n-butyllithium was added to the pressure-resistant container as a polymerization initiator, and then polymerization was carried out at 50 ° C. for 1.5 hours. The polymerization conversion rate at this time was almost 100%.
Subsequently, 5.23 mmol of isopropanol was added to the polymerization reaction system, and the reaction was carried out for 15 minutes. Then, 15.69 mmol of sec-butyllithium and 15.69 mmol of tetramethylethylenediamine were added to the above polymer solution, and the reaction was carried out at 80 ° C. for 30 minutes. To the polymer solution obtained after the reaction, 15.69 mmol of modifier 1 [N, N-bis (trimethylsilyl) -3-aminopropylmethyldimethoxysilane] was added, and the mixture was reacted at 50 ° C. for 30 minutes. Then, 3 ml of a solution of 2,6-di-t-butyl-p-cresol (BHT) in 5% by mass of isopropanol was added to the polymerization reaction system to stop the reaction, and the reaction product was dried according to a conventional method to modify the weight. A coalesced polymer D was obtained.

[Production of polymer E]
A cyclohexane solution of 1,3-butadiene and a cyclohexane solution of styrene were added to a dry, nitrogen-substituted 5 liter pressure vessel to make up 413 grams of 1,3-butadiene and 97 grams of styrene. Further, 2.62 mmol of 2,2-ditetrahydrofurylpropane was added to the pressure-resistant container, 5.23 mmol of n-butyllithium was added, and then polymerization was carried out at 50 ° C. for 1.5 hours. The polymerization conversion rate at this time was almost 100%.
Subsequently, a cyclohexane solution of 1,3-butadiene containing 138 grams of 1,3-butadiene, a cyclohexane solution of styrene containing 32 grams of styrene, and 15.69 mmol of 4-methylstyrene were added to the polymerization reaction system for 1 hour. Polymerization was performed. Further, 5.23 mmol of isopropanol was added to the polymerization reaction system, and the reaction was carried out for 15 minutes. Then, 15.69 mmol of sec-butyllithium and 15.69 mmol of tetramethylethylenediamine were added to the above polymer solution, and the reaction was carried out at 80 ° C. for 30 minutes. To the polymer solution obtained after the reaction, 15.69 mmol of modifier 1 [N, N-bis (trimethylsilyl) -3-aminopropylmethyldimethoxysilane] was added, and the mixture was reacted at 50 ° C. for 30 minutes. Then, 3 ml of a solution of 2,6-di-t-butyl-p-cresol (BHT) in 5% by mass of isopropanol was added to the polymerization reaction system to stop the reaction, and the reaction product was dried according to a conventional method to modify the weight. A coalesced polymer E was obtained.

[Production of polymer F]
A cyclohexane solution of 1,3-butadiene and a cyclohexane solution of styrene were added to a dry, nitrogen-substituted 5 liter pressure vessel to make up 551 grams of 1,3-butadiene and 129 grams of styrene. Further, to the pressure-resistant container, 15.69 mmol of 4-methylstyrene and 2.62 mmol of 2,2-ditetrahydrofurylpropane were further added, and 5.23 mmol of n-butyllithium was further added as a polymerization initiator. Polymerization was carried out at 50 ° C. for 1.5 hours. The polymerization conversion rate at this time was almost 100%.
Subsequently, 5.23 mmol of isopropanol was added to the polymerization reaction system, and the reaction was carried out for 15 minutes. Then, 15.69 mmol of sec-butyllithium and 15.69 mmol of tetramethylethylenediamine were added to the above polymer solution, and the reaction was carried out at 80 ° C. for 30 minutes. 15.69 mmol of modifier 2 [N- [2-N', N'-bis (trimethylsilyl) aminoethyl] -N- (trimethylsilyl) -3-aminopropyltriethoxy was added to the polymer solution obtained after the reaction. Silane] was added and reacted at 50 ° C. for 30 minutes. Then, 3 ml of a solution of 2,6-di-t-butyl-p-cresol (BHT) in 5% by mass of isopropanol was added to stop the reaction, and the reaction product was dried according to a conventional method to obtain a polymer which is a modified polymer. I got F.

[Production of polymer G]
A cyclohexane solution of 1,3-butadiene and a cyclohexane solution of styrene were added to a dry, nitrogen-substituted 5 liter pressure vessel to make up 413 grams of 1,3-butadiene and 97 grams of styrene. Further, 2.62 mmol of 2,2-ditetrahydrofurylpropane was added to the pressure-resistant container, 5.23 mmol of n-butyllithium was added, and then polymerization was carried out at 50 ° C. for 1.5 hours. The polymerization conversion rate at this time was almost 100%.
Subsequently, a cyclohexane solution of 1,3-butadiene containing 138 grams of 1,3-butadiene, a cyclohexane solution of styrene containing 32 grams of styrene, and 15.69 mmol of 4-methylstyrene were added to the polymerization reaction system for 1 hour. Polymerization was performed. Further, 5.23 mmol of isopropanol was added to the polymerization reaction system, and the reaction was carried out for 15 minutes. Then, 15.69 mmol of sec-butyllithium and 15.69 mmol of tetramethylethylenediamine were added to the above polymer solution, and the reaction was carried out at 80 ° C. for 30 minutes. 15.69 mmol of modifier 2 [N- [2-N', N'-bis (trimethylsilyl) aminoethyl] -N- (trimethylsilyl) -3-aminopropyltriethoxy was added to the polymer solution obtained after the reaction. Silane] was added and reacted at 50 ° C. for 30 minutes. Then, 3 ml of a solution of 2,6-di-t-butyl-p-cresol (BHT) in 5% by mass of isopropanol was added to stop the reaction, and the reaction product was dried according to a conventional method to obtain a polymer which is a modified polymer. I got G.

[Production of polymer H]
A cyclohexane solution of 1,3-butadiene and a cyclohexane solution of styrene were added to a dry, nitrogen-substituted 5 liter pressure vessel to 524 grams of 1,3-butadiene and 123 grams of styrene. Further, 2.62 mmol of 2,2-ditetrahydrofurylpropane was added to the pressure-resistant container, 5.23 mmol of n-butyllithium was added, and then polymerization was carried out at 50 ° C. for 1.5 hours. The polymerization conversion rate at this time was almost 100%.
Subsequently, a cyclohexane solution of 1,3-butadiene containing 28 grams of 1,3-butadiene, a cyclohexane solution of styrene containing 6 grams of styrene, and 15.69 mmol of 4-methylstyrene were added to the polymerization reaction system for 1 hour. Polymerization was performed. Further, 5.23 mmol of isopropanol was added to the polymerization reaction system, and the reaction was carried out for 15 minutes. Then, 15.69 mmol of sec-butyllithium and 15.69 mmol of tetramethylethylenediamine were added to the above polymer solution, and the reaction was carried out at 80 ° C. for 30 minutes. To the polymer solution obtained after the reaction, 15.69 mmol of modifier 1 [N, N-bis (trimethylsilyl) -3-aminopropylmethyldimethoxysilane] was added, and the mixture was reacted at 50 ° C. for 30 minutes. Then, 3 ml of a 5 wt% solution of 2,6-di-t-butyl-p-cresol (BHT) in isopropanol was added to terminate the reaction, and the reaction product was dried according to a conventional method to obtain a polymer which is a modified polymer. I got H.

<Characteristics of polymers A to H>
The number of modifier residues of the polymers A to H produced as described above, the type of modifiers constituting the modifier residues, the position of the modifier residues, and the diene polymer between the modifier residues. Table 1 shows the presence or absence of a monomer structure, the presence or absence of direct binding between modifier residues, and the molecular properties of the polymer.
The amount of bound styrene of the polymer (content of styrene unit in the polymer) and vinyl viscosity (% by mass) of the polymer in Table 1 were determined from the integration ratio ^{of the 1 H-NMR spectrum.} The Mooney viscosity (ML _{1 +} 4/100 ° C.) of the polymer was measured at a temperature of 100 ° C. using an RLM-01 type tester manufactured by Toyo Seiki Co., Ltd. in accordance with JIS K6300-1994.

In addition, the characteristics of the polymers A to H are also briefly shown in Tables 2 to 4.
In Tables 2 to 4, "modified polymer (one, one end)" means that the polymer has one modifier residue on the main chain and the position of the modifier residue is the main chain. It means that it is one end.
"Modified polymer (3, whole)" means that the polymer has 3 modifier residues on the main chain and the positions of the modifier residues are evenly distributed throughout the main chain. means.
"Modified polymer (3, 1/4)" means that the polymer has three denaturing agent residues on the main chain, and the total denaturing agent residue is from one end of the main chain to the main chain. It means that it is located only in the range of 1/4 of the total chain length of.
"Modified polymer (3, 1/20)" means that the polymer has three denaturing agent residues on the main chain, and the total denaturing agent residue is from one end of the main chain to the main chain. It means that it is located only in the range of 1/20 of the total chain length of.
"Unmodified polymer (0,-)" means that the polymer has no denaturing agent residue on the main chain.

<Preparation of rubber composition and manufacture of tires>
Each component was kneaded with a Banbury mixer according to the formulation shown in Tables 2 to 4 to prepare a rubber composition. Next, the prepared rubber composition was obtained under the conditions of a vulcanization temperature of 145 ° C. and a vulcanization time of 45 minutes.
In addition, a tire (tire size: 195 / 65R15) was prototyped using the prepared rubber composition as a tread rubber.

<Evaluation>
Using the rubber composition prepared as described above or the vulcanized rubber obtained under the above conditions, a kneaded skin evaluation, a workability evaluation, an abrasion resistance evaluation, and a low heat generation evaluation were performed.
Details of each evaluation method are shown below. The evaluation results are shown in Tables 2-4.

[Kneaded skin evaluation]
The prepared vulcanized rubber composition was extruded and molded, and the sheet properties of the obtained rubber sheet were visually evaluated according to the following criteria. The smoother the sheet surface and the less brittle the sheet, the better the workability.
A: The sheet surface is very smooth and there is no surface roughness.
B: The sheet surface is smooth.
C: The sheet shape is maintained, but the surface is rough and the surface is uneven.
D: The sheet becomes brittle and it is difficult to maintain the sheet shape (physical characteristics cannot be evaluated).

[Workability evaluation]
With respect to the prepared rubber composition, in accordance with JIS-K6300-1: 2001, a Mooney viscometer (RPA manufactured by Monsanto Co., Ltd.) was used, and an L-shaped rotor was used. ML _{1 +} 4/130 ° C.] was measured.
The value of Mooney viscosity of the obtained rubber composition is expressed exponentially with the value of Comparative Example 1 as 100. The smaller the index value, the better the flowability of the rubber composition and the better the workability. The permissible range is 110 or less.

[Abrasion resistance evaluation]
With respect to the obtained vulcanized rubber, the amount of wear at a slip ratio of 60% at room temperature was measured using a lambourn type wear tester.
The reciprocal of the amount of wear of the vulcanized rubber of Comparative Example 1 was set as 100 and displayed as an index. The larger the index value, the smaller the amount of wear and the better the wear resistance.

[Evaluation of low heat generation]
The loss tangent (tan δ) of the obtained vulcanized rubber was measured using a viscoelasticity measuring device (manufactured by Leometrics) under the conditions of a temperature of 50 ° C., a strain of 5%, and a frequency of 15 Hz. The obtained value of tan δ was exponentially displayed with the value of Comparative Example 1 as 100. The smaller the index value, the better the low loss property and the good low heat generation property.

Details of * 1 to * 8 in Tables 2 to 4 are as follows.
* 1: AQ, Nip Seal AQ, manufactured by Toso Silica * 2: Process oil, A / O MIX, manufactured by Sankyo Yuka Kogyo Co., Ltd. * 3: Carbon black: "Diamond Black N234" manufactured by Mitsubishi Chemical Corporation
* 4: N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine * 5-1: bis- [γ- (triethoxysilyl) -propyl] -tetrasulfide, Si69, ebonic degussa * 5-2: 3- (Octanoylthio) -1-propyltriethoxysilane, Momentive * 6: Diphenylguanidine, Noxeller D, Ouchi Shinko Kagaku Kogyo Co., Ltd. * 7: Dibenzothiazil disulfide, Noxeller DM- P, manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. * 8: Nt-butyl-2-benzothiazyl sulfenamide, Noxeller NS-P, manufactured by Ouchi Shinko Kagaku Kogyo

As can be seen from Comparative Examples 4 to 8, even if the diene polymer (A) in the present invention is used together with a conventional silane coupling agent other than the silane coupling agent (C) in the present invention, workability and wear resistance It was found that the performance deteriorated to the extent that the sex and low heat generation could not be evaluated. Further, as can be seen from Comparative Examples 9 to 11, even when the silane coupling agent (C) in the present invention is used, the polymer used together is an unmodified polymer or a conventional one-ended modified polymer. Although it was excellent in the evaluation of kneaded skin and workability, it was not excellent in the wear resistance and low heat generation of the vulcanized rubber. In Comparative Examples 1 to 3 using an unmodified polymer or a conventional one-ended modified polymer and a conventional silane coupling agent, none of the evaluation items was excellent.

On the other hand, in the example using the diene polymer (A) and the silane coupling agent (C) in the present invention, the workability and the abrasion resistance are excellent, the kneaded skin evaluation is excellent, and further, it is low. It was found that the exothermic evaluation was significantly superior to that of the comparative example.

Claims (14)

A rubber component containing a diene polymer (A) having three or more modifier residues having an alkoxysilyl group in the main chain per molecule,
Silica (B) and
Silane coupling agents represented by the following general formula (I) and (C) seen including,
The modifier residue having an alkoxysilyl group is derived from the hydrocarbyloxysilane compound represented by the following general formula (V) or the hydrocarbyloxysilane compound represented by the following general formula (VIII). Is a rubber composition.



[In formula (I) , R ¹ is R ⁶ O-, R ⁶ C (= O) O-, R ⁶ R ⁷ C = NO-, R ⁶ R ⁷ NO-, R ⁶ R ⁷ N- and-. It is any one selected from the group consisting of (OSiR ⁶ R ⁷ ) _m (OSiR ⁵ R ⁶ R ^{7), and has 1 to 18 carbon atoms.} However, R ⁶ and R ⁷ are each independently selected from the group consisting of an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group and an aryl group, and have 1 to 1 carbon atoms. It is 18. m is 1 to 4.
R ² is any one selected from the group consisting of a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, an alkenyl group, a cycloalkenyl group and an aryl group.
R ³ is − [O (R ⁸ O) _p ] _0.5 − groups. However, R ⁸ is any one selected from the group consisting of an alkylene group and a cycloalkylene group, and has 1 to 18 carbon atoms. p is 1 to 4).
x, y, and z satisfy x + y + 2z = 3, 0 ≦ x ≦ 3, 0 ≦ y ≦ 2, and 0 ≦ z ≦ 1.
R ⁴ is any one selected from the group consisting of an alkylene group, a cycloalkylene group, a cycloalkylalkylene group, an alkenylene group, an arylene group and an aralkylene group, and has 1 to 18 carbon atoms.
R ⁵ is any one selected from the group consisting of an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group and an aralkyl group, and has 1 to 18 carbon atoms.
_{^{R 1, R 2, R 6}} , if ^{R 7,} which and ^{R 8} are a ^{plurality, _{R 1, R 2, R 6}} , ^{R 7,} and ^{R 8} each independently be different even in the same Good. ]
[In the formula (V), q1 + q2 = 3 (where q1 is an integer of 0 to 2 and q2 is an integer of 1 to 3).
R ³¹ is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ³² and R ³³ are independently hydrolyzable groups, monovalent aliphatic or alicyclic hydrocarbon groups having 1 to 20 carbon atoms, or monovalent aromatic hydrocarbon groups having 6 to 18 carbon atoms, respectively. ..
R ³⁴ is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and is the same or different when q1 is 2. You may.
R ³⁵ is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and when q2 is 2 or more, it is the same or different. You may. However, ^{at least one of R 35} is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms. ]
[In formula (VIII), TMS is a trimethylsilyl group, and R ⁴³ and R ⁴⁴ are independently divalent aliphatic or alicyclic hydrocarbon groups having 1 to 20 carbon atoms or 2 carbon atoms 6 to 18 respectively. It is a valent aromatic hydrocarbon group.
R ⁴⁵ is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and a plurality of R ^45s are the same but different. May be good. However, ^{at least one of R 45} is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms. ] The rubber composition according to claim 1, wherein the hydrocarbyloxysilane compound represented by the general formula (V) is N, N-bis (trimethylsilyl) -3-aminopropylmethyldimethoxysilane. The hydrocarbyloxysilane compound represented by the following general formula (VIII) is N- [2-N', N'-bis (trimethylsilyl) aminoethyl] -N- (trimethylsilyl) -3-aminopropyltriethoxysilane. The rubber composition according to claim 1. The rubber composition according to any one of claims 1 to 3, wherein the diene-based polymer (A) has a monomer structure of the diene-based polymer between at least one of the modifier residues. The rubber composition according to claim 4 , wherein the diene-based polymer (A) has a monomer structure of the diene-based polymer between all the modifier residues. The rubber composition according to any one of claims 1 to 5 , wherein the modifier residue further has at least one selected from the group consisting of nitrogen atoms and oxygen atoms. The diene-based polymer (A) is a homopolymer composed of diene-based monomer units, or a diene-based monomer unit of 60% by mass or more and less than 100% by mass, and more than 0% by mass and 40% by mass or less. The rubber composition according to any one of claims 1 to 6 , which is a copolymer having an aromatic vinyl compound unit. The rubber composition according to claim 7 , wherein the diene-based monomer unit is a 1,3-butadiene unit. The rubber composition according to claim 7 or 8 , wherein the aromatic vinyl compound unit is a styrene unit. The rubber composition according to any one of claims 1 to 9 , wherein the content of the diene polymer (A) in the rubber component is 10% by mass or more. The present invention according to any one of claims 1 to 10 , wherein the diene polymer (A) has three or more denaturant residues only in the range from the end to 1/4 of the total chain length of the main chain. The rubber composition described. The rubber composition according to any one of claims 1 to 11 , wherein the content of silica (B) is 60 to 250 parts by mass with respect to 100 parts by mass of the rubber component. The item according to any one of claims 1 to 12 , wherein the content of the silane coupling agent (C) is 1 to 20 parts by mass with respect to 100 parts by mass of the silica (B) content. Rubber composition. A tire using the rubber composition according to any one of claims 1 to 13 as a tread member.