JP2018009054A - Rubber composition for tire, and tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition for a tire which is excellent in extrusion processability and scorch resistance, and to provide a tire using the rubber composition for a tire.SOLUTION: The rubber composition for a tire contains a diene rubber, silica, a silane coupling agent having a mercapto group, and a cationic surfactant. The cationic surfactant is a quaternary ammonium salt having an amide bond or a carboxylic acid ester bond. The content of the silica is 50-200 pts.mass based on 100 pts.mass of the diene rubber. The content of the silane coupling agent is 1-15 pts.mass based on 100 pts.mass of the diene rubber. The content of the cationic surfactant is 0.05-10 pts.mass based on 100 pts.mass of the diene rubber.SELECTED DRAWING: None

Description

  The present invention relates to a tire rubber composition and a tire.

In recent years, there has been a demand for reducing tire rolling resistance in order to improve fuel efficiency during vehicle travel. Therefore, a method is known in which diene rubber constituting the tread portion of the tire is mixed with silica to reduce hysteresis loss (particularly tan δ at high temperature) to reduce heat generation and reduce tire rolling resistance. Yes.
However, since silica has low affinity with diene rubbers and high cohesiveness between silicas, silica is not dispersed even if silica is simply blended with diene rubbers, reducing the rolling resistance of tires. There was a problem that could not be obtained sufficiently.

Under such circumstances, for example, in claim 1 of Patent Document 1, “5 to 100 parts by weight of silica is blended with 100 parts by weight of the diene rubber, and a specific mercaptosilane (1) is added in an amount of 0. A rubber composition for tires, in which 5 to 4.0% by weight and a specific mercaptosilane (2) are blended at 0.5 to 10% by weight of the silica blending amount and mixed at a temperature of 145 to 185 ° C. Is disclosed.
Patent Document 1 describes that by using the rubber composition for tires produced by the above method, the hysteresis loss of the tire can be reduced and the rolling resistance can be sufficiently reduced.

JP 2010-270247 A

Recently, in addition to the reduction in rolling resistance described above, further improvements in extrusion processability and scorch resistance are required from the viewpoint of productivity and the like.
Under such circumstances, the rubber composition containing the diene rubber, silica, and a silane coupling agent having a mercapto group (hereinafter also referred to as “mercapto silane coupling agent”) based on Patent Document 1 by the present inventors. Examination of the product revealed that extrudability and scorch resistance do not always meet the levels required recently.

  Then, an object of this invention is to provide the tire using the rubber composition for tires excellent in extrusion workability and scorch resistance, and the said rubber composition for tires in view of the said situation.

As a result of intensive studies on the above problems, the present inventors have found that the above problems can be solved by using a mercapto-based silane coupling agent and a specific cationic surfactant together, and have reached the present invention.
That is, the present inventors have found that the above problem can be solved by the following configuration.

(1) containing a diene rubber, silica, a silane coupling agent having a mercapto group, and a cationic surfactant,
The cationic surfactant is a quaternary ammonium salt having an amide bond or a carboxylic ester bond,
The content of the silica is 50 to 200 parts by mass with respect to 100 parts by mass of the diene rubber.
The content of the silane coupling agent is 1 to 15 parts by mass with respect to 100 parts by mass of the diene rubber.
A tire rubber composition, wherein the content of the cationic surfactant is 0.05 to 10 parts by mass with respect to 100 parts by mass of the diene rubber.
(2) The silane coupling agent has a compound represented by the formula (A1) described later, a repeating unit represented by the formula (A3) described later, and a repeating unit represented by the formula (A4) described later. The tire rubber composition according to the above (1), which is a polymer or a polysiloxane represented by an average formula of the formula (1) described later.
(3) The rubber composition for tires according to (1) or (2) above, wherein the silica has a CTAB adsorption specific surface area of 140 to 300 m ² / g.
(4) A tire manufactured using the tire rubber composition according to any one of (1) to (3).

  As shown below, according to the present invention, it is possible to provide a tire rubber composition excellent in extrudability and scorch resistance, and a tire using the tire rubber composition.

It is a partial section schematic diagram of the tire showing an example of an embodiment of a tire of the present invention.

The tire rubber composition of the present invention and the tire of the present invention are described below.
In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

[Rubber composition for tire]
The rubber composition for tires of the present invention (hereinafter also referred to as “the composition of the present invention”) contains a diene rubber, silica, a silane coupling agent having a mercapto group, and a cationic surfactant.
Here, the cationic surfactant is a quaternary ammonium salt having an amide bond or a carboxylic acid ester bond. Further, the content of the silica is 50 to 200 parts by mass with respect to 100 parts by mass of the diene rubber, and the content of the silane coupling agent is 1 with respect to 100 parts by mass of the diene rubber. The content of the cationic surfactant is 0.05 to 10 parts by mass with respect to 100 parts by mass of the diene rubber.
Since the composition of this invention takes such a structure, it is thought that a desired effect is acquired. The reason is not clear, but it is thought to be as follows.

When a mercapto silane coupling agent is blended with a rubber composition containing silica, the dispersibility of silica is improved by connecting the rubber and silica with the mercapto silane coupling agent. However, the inventors' studies have shown that dispersed silica may re-agglomerate and extrusion processability may be insufficient.
In the composition of the present invention, a quaternary ammonium salt having an amide bond or a carboxylic ester bond (hereinafter also referred to as “specific cationic surfactant”) as a cationic surfactant together with a mercapto silane coupling agent is used. The specific cationic surfactant assists the connection between the rubber and the silica, so that the reaggregation of silica is suppressed, and as a result, it is considered that excellent extrudability is exhibited.
In addition, when a mercapto-based silane coupling agent is used, scorch is likely to occur due to the high reactivity of the mercapto group. Therefore, the composition of the present invention is considered to have excellent scorch resistance.

  Hereinafter, each component contained in the composition of the present invention will be described.

[Diene rubber]
The diene rubber contained in the composition of the present invention is not particularly limited, and specific examples thereof include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), aromatic vinyl-conjugated diene copolymer. Examples include coal rubber, acrylonitrile-butadiene copolymer rubber (NBR), butyl rubber (IIR), halogenated butyl rubber (Br-IIR, Cl-IIR), and chloroprene rubber (CR). The diene rubber may be a single diene rubber or a combination of two or more diene rubbers.

As the diene rubber, it is preferable to use an aromatic vinyl-conjugated diene copolymer rubber for the reason that the obtained tire has excellent rigidity, and butadiene rubber (BR) is used in combination with the aromatic vinyl-conjugated diene copolymer. More preferably.
Examples of the aromatic vinyl-conjugated diene copolymer rubber include styrene butadiene rubber (SBR) and styrene isoprene copolymer rubber. Among these, styrene butadiene rubber (SBR) is preferable because the rigidity of the obtained tire is excellent.

The aromatic vinyl content (for example, styrene content) of the aromatic vinyl-conjugated diene copolymer is preferably 20 to 45% by mass for the reason that the effect of the present invention is more excellent, and 23 to 42% by mass. % Is more preferable.
The vinyl bond content in the conjugated diene of the aromatic vinyl-conjugated diene copolymer is preferably 10 to 50%, more preferably 25 to 48%, because the effect of the present invention is more excellent. More preferred. Here, the amount of vinyl bonds refers to the ratio of 1,2-vinyl bonds among cis-1,4-bonds, trans-1,4-bonds and 1,2-vinyl bonds, which are conjugated dienes. Say.

The said aromatic vinyl-conjugated diene copolymer is not specifically limited about the manufacturing method, It can manufacture by a conventionally well-known method.
Moreover, the aromatic vinyl and conjugated diene as a monomer used when manufacturing the said aromatic vinyl-conjugated diene copolymer are not specifically limited.
Here, examples of the conjugated diene monomer include 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2,3-dimethyl-1,3-butadiene, and 2-chloro-1. , 3-butadiene, 1,3-pentadiene and the like.
On the other hand, examples of the aromatic vinyl monomer include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, Examples include 4-tert-butylstyrene, divinylbenzene, tert-butoxystyrene, vinylbenzyldimethylamine, (4-vinylbenzyl) dimethylaminoethyl ether, N, N-dimethylaminoethylstyrene, and vinylpyridine.

The content in the case of using the aromatic vinyl-conjugated diene copolymer is preferably 50 to 100% by mass of the diene rubber, and is preferably 55 to 95% by mass, because the rigidity of the obtained tire is excellent. More preferably, it is more preferably 60 to 90% by mass.
Further, when the butadiene rubber (BR) is used in combination with the aromatic vinyl-conjugated diene copolymer, the content of the butadiene rubber (BR) is the reason why the effect of the present invention is more excellent, It is preferably 5 to 50% by mass, more preferably 10 to 45% by mass, and further preferably 20 to 40% by mass.

  The weight average molecular weight of the diene rubber (particularly the aromatic vinyl-conjugated diene copolymer) is not particularly limited, but is preferably 100,000 to 1,500,000 from the viewpoint of handling, More preferably, it is 000-1,300,000. In addition, the weight average molecular weight (Mw) of diene rubber shall be measured by standard polystyrene conversion by the gel permeation chromatography (GPC) which uses tetrahydrofuran as a solvent.

  The Tg (glass transition temperature) of the diene rubber (especially the aromatic vinyl-conjugated diene copolymer) is not particularly limited, but is −70 to −10 ° C. because the effect of the present invention is more excellent. Is more preferable, and it is more preferably −40 to −20 ° C.

〔silica〕
The silica contained in the composition of the present invention is not particularly limited, and any conventionally known silica compounded in a rubber composition for uses such as tires can be used. Examples thereof include wet silica, dry silica, fumed silica, diatomaceous earth, and the like. As the silica, one type of silica may be used alone, or two or more types of silica may be used in combination.
Although the CTAB (cetyltrimethylammonium bromide) adsorption specific surface area of silica is not particularly limited, it is preferably 140 to 300 m ² / g and more preferably 140 to 210 m ² / g because the effect of the present invention is more excellent. More preferred.
In the present specification, the CTAB adsorption specific surface area is a value obtained by measuring the CTAB adsorption amount on the silica surface in accordance with JIS K6217-3: 2001 “Part 3: Determination of specific surface area—CTAB adsorption method”.

  In the composition of the present invention, the content of silica is 50 to 200 parts by mass with respect to 100 parts by mass of the diene rubber. Especially, since the effect of this invention is more excellent, it is preferable that it is 70-150 mass parts.

[Mercapto silane coupling agent]
The silane coupling agent having a mercapto group (mercapto silane coupling agent) contained in the composition of the present invention is not particularly limited as long as it is a silane compound having a mercapto group (—SH) and a hydrolyzable group.
The hydrolyzable group is not particularly limited, and examples thereof include an alkoxy group, a phenoxy group, a carboxyl group, and an alkenyloxy group. Among these, an alkoxy group is preferable because the effect of the present invention is more excellent. When the hydrolyzable group is an alkoxy group, the alkoxy group preferably has 1 to 16 carbon atoms, more preferably 1 to 4 carbon atoms. As a C1-C4 alkoxy group, a methoxy group, an ethoxy group, a propoxy group etc. are mentioned, for example.

The mercapto-based silane coupling agent may have an organic functional group other than a mercapto group.
Such an organic functional group is not particularly limited, and examples thereof include an epoxy group, a vinyl group, an acryloyl group, a methacryloyl group, and an amino group.

  A mercapto silane coupling agent may be used individually by 1 type, and may use 2 or more types together.

  Specific examples of the mercapto-based silane coupling agent include mercaptopropyltrimethoxysilane and mercaptopropyltriethoxysilane.

<Preferred embodiment>
The mercapto silane coupling agent is a mercapto silane having a polyether chain and / or a mercapto silane having a polysiloxane structure (-Si-O-) because the effects of the present invention are more excellent. A coupling agent is preferred.
Here, the polyether chain is a side chain having two or more ether bonds, and specific examples thereof include, for example, side chains having two or more structural units —R ^a —O—R ^b — in total. Can be mentioned. Here, in the structural unit, R ^a and R ^b are each independently a linear or branched alkylene group, a linear or branched alkenylene group, a linear or branched alkynylene group, Alternatively, it represents a substituted or unsubstituted arylene group. Of these, a linear alkylene group is preferable.

As a suitable aspect of the mercapto type | system | group silane coupling agent which has the said polyether chain | strand, the compound represented by Formula (A1) mentioned later is mentioned, for example.
Moreover, as a suitable aspect of the mercapto type | system | group silane coupling agent which has the said polysiloxane structure, it has a repeating unit represented, for example by the repeating unit represented by the formula (A3) mentioned later, and the formula (A4) mentioned later, for example. Examples include copolymers and polysiloxanes represented by the average formula of the following formula (1).

(Compound represented by Formula (A1))

In the formula ^{(A1), R 11} represents an alkoxy group having 1 to 8 carbon atoms, among them, preferably an alkoxy group having 1 to 3 carbon atoms. Examples of the alkoxy group having 1 to 3 carbon atoms include a methoxy group and an ethoxy group. A plurality of R ¹¹ in the case where l is 2 may be the same or different.
In the formula ^{(A1), R 12} represents a straight-chain polyether group having 4 to 30 carbon atoms. The polyether group is a group having two or more ether bonds, and specific examples thereof include a group having two or more structural units —R ^a —O—R ^b — in total. Here, R ^a and R ^b are each independently a linear or branched alkylene group, a linear or branched alkenylene group, a linear or branched alkynylene group, or a substituted or unsubstituted group. Represents a substituted arylene group. Of these, a linear alkylene group is preferable. A plurality of R ¹² in the case where m is 2 may be the same or different.
As a suitable aspect of a C4-C30 linear polyether group, group represented by a following formula (A2) is mentioned, for example.

In the above formula (A2), R ²¹ represents a linear alkyl group, a linear alkenyl group, or a linear alkynyl group, and among them, a linear alkyl group is preferable. As the linear alkyl group, a linear alkyl group having 1 to 20 carbon atoms is preferable, and a linear alkyl group having 8 to 15 carbon atoms is more preferable. Specific examples of the linear alkyl group having 8 to 15 carbon atoms include octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group and the like, and tridecyl group is particularly preferable.
In the above formula (A2), R ²² represents a linear alkylene group, a linear alkenylene group, or a linear alkynylene group, and among them, a linear alkylene group is preferable. As said linear alkylene group, a C1-C2 linear alkylene group is preferable and an ethylene group is more preferable.
In said formula (A2), p represents the integer of 1-10 and it is preferable that it is 3-7.
In the above formula (A2), * indicates a bonding position.

In the above formula (A1), R ¹³ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.
In the formula ^{(A1), R 14} represents an alkylene group having 1 to 30 carbon atoms, among them preferably an alkylene group having 1 to 12 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms. Specific examples of the alkylene group having 1 to 5 carbon atoms include a methylene group, an ethylene group, and a propylene group.
In said formula (A1), l represents the integer of 1-2 and it is preferable that it is 1. In said formula (A1), m represents the integer of 1-2 and it is preferable that it is 2. n represents an integer of 0 to 1, and is preferably 0. l, m, and n satisfy the relationship of l + m + n = 3.

(Copolymer having repeating unit represented by formula (A3) and repeating unit represented by formula (A4))

In the above formulas (A3) and (A4), R ³¹ and R ⁴¹ each independently represent an alkylene group having 1 to 5 carbon atoms. Specific examples thereof include a methylene group, an ethylene group, and a propylene group. It is done. Of these, a propylene group is preferred. A plurality of R ³¹ and R ⁴¹ may be the same or different.
In the above formulas (A3) and (A4), R ³² and R ⁴² each independently represent a linear or branched alkylene group having 1 to 30 carbon atoms, or a linear or branched carbon number of 2 to 30. The alkenylene group or the linear or branched alkynylene group having 2 to 30 carbon atoms is preferable, and those having 3 to 20 carbon atoms are preferable. When R ³² is a terminal, R ³² is a hydrogen atom, a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, or a straight chain. It represents a chain or branched alkynyl group having 2 to 30 carbon atoms, and among them, those having 3 to 20 carbon atoms are preferable. If R ⁴² is ^terminated, the definition of ^{R 42,} specific examples and preferred embodiments are the same as above ^{R 32.} A plurality of R ³² and R ⁴² may be the same or different.
In the above formulas (A3) and (A4), R ³³ and R ⁴³ are each independently a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched group. A alkenyl group having 2 to 30 carbon atoms, a linear or branched alkynyl group having 2 to 30 carbon atoms, a linear or branched alkyl group having 1 to 30 carbon atoms, and a hydroxyl group or a carboxyl group at the terminal Or a linear or branched alkenyl group having 2 to 30 carbon atoms and having a hydroxyl group or a carboxyl group at the terminal. R ⁴³ is preferably a group having a hydroxyl group at the terminal. R ³² and R ³³ may form a ring with R ³² and R ³³ . R ⁴² and R ⁴³ may form a ring with R ⁴² and R ⁴³ . A plurality of R ³³ and R ⁴³ may be the same or different.
R ³⁴ represents an alkyl group having 1 to 13 carbon atoms, and among them, an alkyl group having 3 to 10 carbon atoms is preferable. Specific examples of the alkyl group having 3 to 10 carbon atoms include a hexyl group, a heptyl group, and an octyl group. A plurality of R ³⁴ may be the same or different.

(Polysiloxane represented by the average formula of formula (1))
_{(A) a (B) b} (C) c (D) d (R 1) e SiO (4-2a-b-c-d-e) / 2 (1)

In the above formula (1), A represents a divalent organic group containing a sulfide group. Especially, it is preferable that it is group represented by following formula (2).
^{_{* - (CH 2) n -S}} x - (CH 2) n - * (2)
In said formula (2), n represents the integer of 1-10, and it is preferable that it is an integer of 2-4 especially.
In said formula (2), x represents the integer of 1-6, and it is preferable that it is an integer of 2-4 especially.
In the above formula (2), * indicates a bonding position.
Specific examples of the group represented by the formula (2) are, for ^{_{example, * -CH 2 -S 2 -CH 2}} - *, * -C 2 H 4 -S 2 -C 2 H 4 - *, * - _{C 3 H 6 -S 2 -C 3} H 6 - *, * -C 4 H 8 -S 2 -C 4 H 8 - *, * -CH 2 -S 4 -CH 2 - *, * -C 2 H _{4 -S 4 -C 2 H 4 -} *, * -C 3 H 6 -S 4 -C 3 H 6 - *, * -C 4 H 8 -S 4 -C 4 H 8 - * , and the like.

  In said formula (1), B represents a C1-C20 monovalent hydrocarbon group, As a specific example, a hexyl group, an octyl group, a decyl group etc. are mentioned, for example. B is preferably a monovalent hydrocarbon group having 5 to 10 carbon atoms.

In the above formula (1), C represents a hydrolyzable group, and specific examples thereof include an alkoxy group, a phenoxy group, a carboxyl group, an alkenyloxy group, and the like. Especially, it is preferable that it is group represented by following formula (3).
^* -OR ² (3)
In the above formula (3), ^{R 2} is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group (aryl alkyl group) or an alkenyl group having 2 to 10 carbon atoms having from 6 to 10 carbon atoms In particular, an alkyl group having 1 to 5 carbon atoms is preferable. Specific examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, and an octadecyl group. Specific examples of the aryl group having 6 to 10 carbon atoms include a phenyl group and a tolyl group. Specific examples of the aralkyl group having 6 to 10 carbon atoms include a benzyl group and a phenylethyl group. Specific examples of the alkenyl group having 2 to 10 carbon atoms include a vinyl group, a propenyl group, and a pentenyl group.
In the above formula (3), * indicates a bonding position.

In said formula (1), D represents the organic group containing a mercapto group. Especially, it is preferable that it is group represented by following formula (4).
^{_{* - (CH 2) m -SH}} (4)
In said formula (4), m represents the integer of 1-10, and it is preferable that it is an integer of 1-5 especially.
In the above formula (4), * indicates a bonding position.
Specific examples of the group represented by the formula ^{_{(4), * -CH 2 SH}} , * -C 2 H 4 SH, * -C 3 H 6 SH, * -C 4 H 8 SH, * -C 5 ^{_{H 10 SH, * -C 6 H}} 12 SH, * -C 7 H 14 SH, * -C 8 H 16 SH, * -C 9 H 18 SH, include _* -C _{10 H} 20 SH.

In the above formula (1), ^{R 1} represents a monovalent hydrocarbon group having 1 to 4 carbon atoms.

  In the above formula (1), a to e are relational expressions of 0 <a <1, 0 <b <1, 0 <c <3, 0 <d <1, 0 ≦ e <2, 0 <2a + b + c + d + e <4. Meet.

  The polysiloxane represented by the average formula of the formula (1) is a group represented by the formula (2) in the formula (1) because the effect of the present invention is more excellent. It is preferable that C in (1) is a group represented by the above formula (3) and D in the above formula (1) is a polysiloxane which is a group represented by the above formula (4).

In the above formula (1), a is preferably 0 <a ≦ 0.50 because the effect of the present invention is more excellent.
In the above formula (1), b is preferably 0 <b, more preferably 0.10 ≦ b ≦ 0.89, because the effect of the present invention is more excellent.
In the above formula (1), c is preferably 1.2 ≦ c ≦ 2.0 because the effect of the present invention is more excellent.
In the above formula (1), d is preferably 0.1 ≦ d ≦ 0.8 because the effect of the present invention is more excellent.

The weight average molecular weight of the polysiloxane is preferably 500 to 2300, more preferably 600 to 1500, because the effect of the present invention is more excellent. The molecular weight of the polysiloxane in the present application is determined in terms of polystyrene by gel permeation chromatography (GPC) using toluene as a solvent.
The mercapto equivalent of the polysiloxane in acetic acid / potassium iodide / potassium iodate addition-sodium thiosulfate solution titration is preferably 550 to 700 g / mol, and preferably 600 to 650 g from the viewpoint of excellent vulcanization reactivity. More preferably, it is / mol.

  The polysiloxane preferably has 2 to 50 siloxane units (—Si—O—) because the effects of the present invention are more excellent.

The method for producing the polysiloxane is not particularly limited. As a first preferred embodiment, an organosilicon compound represented by the following formula (5) and an organosilicon compound represented by the following formula (6) are used. The method of hydrolytic condensation is mentioned. As a second preferred embodiment, an organosilicon compound represented by the following formula (5), an organosilicon compound represented by the following formula (6), and an organosilicon represented by the following formula (7) The method of hydrolyzing and condensing a compound is mentioned. Further, as a third preferred embodiment, an organosilicon compound represented by the following formula (5), an organosilicon compound represented by the following formula (6), and an organosilicon represented by the following formula (7) The method of hydrolyzing and condensing a compound and the organosilicon compound represented by following formula (8) is mentioned.
Especially, it is preferable that it is the said 2nd suitable aspect from the reason for which the effect of this invention is more excellent.

In the above formula ^{(5), R 51} represents an alkyl group, an aryl group or an alkenyl group having 2 to 10 carbon atoms having 6 to 10 carbon atoms having 1 to 20 carbon atoms, among them, alkyl groups of 1 to 5 carbon atoms It is preferable that Specific examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, and an octadecyl group. Specific examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, a tolyl group, and a naphthyl group. Specific examples of the alkenyl group having 2 to 10 carbon atoms include a vinyl group, a propenyl group, and a pentenyl group.
In the above formula ^(5), (preferably, 1 to 10) ^{R 52} having a carbon number of 1 to 20 alkyl group or a C6-C20 (preferably, 6-10) represents an aryl group. Specific examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, and a decyl group. Specific examples of the aryl group of the C6-20 is as defined above R ^2.
In the above formula (5), the definition and preferred aspects of n are the same as n in the above formula (2).
In the above formula (5), the definition and preferred embodiment of x are the same as x in the above formula (2).
In said formula (5), y represents the integer of 1-3.

  Specific examples of the organosilicon compound represented by the above formula (5) include, for example, bis (trimethoxysilylpropyl) tetrasulfide, bis (triethoxysilylpropyl) tetrasulfide, bis (trimethoxysilylpropyl) disulfide, bis (Triethoxysilylpropyl) disulfide and the like.

In the above formula (6), the definition, specific examples and preferred embodiments of R ⁶¹ are the same as those of R ⁵¹ described above.
In the above formula (6), the definition, specific examples and preferred embodiments of R ⁶² are the same as those of R ⁵² described above.
In the above formula (6), the definition of z is the same as the above y.
In said formula (6), p represents the integer of 5-10.

  Specific examples of the organosilicon compound represented by the above formula (6) include, for example, pentyltrimethoxysilane, pentylmethyldimethoxysilane, pentyltriethoxysilane, pentylmethyldiethoxysilane, hexyltrimethoxysilane, and hexylmethyldimethoxysilane. , Hexyltriethoxysilane, hexylmethyldiethoxysilane, octyltrimethoxysilane, octylmethyldimethoxysilane, octyltriethoxysilane, octylmethyldiethoxysilane, decyltrimethoxysilane, decylmethyldimethoxysilane, decyltriethoxysilane, decylmethyl Examples include diethoxysilane.

In the above formula (7), the definition, specific examples and preferred embodiments of R ⁷¹ are the same as those of R ⁵¹ described above.
In the above formula (7), the definition, specific examples and preferred embodiments of R ⁷² are the same as those of R ⁵² described above.
In the above formula (7), the definition and preferred embodiment of m are the same as m in the above formula (4).
In the above formula (7), the definition of w is the same as y.

  Specific examples of the organosilicon compound represented by the above formula (7) include, for example, α-mercaptomethyltrimethoxysilane, α-mercaptomethylmethyldimethoxysilane, α-mercaptomethyltriethoxysilane, α-mercaptomethylmethyldi Examples include ethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-mercaptopropylmethyldiethoxysilane.

In the above formula (8), the definition, specific examples and preferred embodiments of R ⁸¹ are the same as those of R ⁵¹ described above.
In the above formula (8), the definition, specific examples and preferred embodiments of R ⁸² are the same as those of R ⁵² described above.
In the above formula (8), the definition of v is the same as y above.
In said formula (8), q represents the integer of 1-4.

  Specific examples of the organosilicon compound represented by the above formula (8) include, for example, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, methylethyldiethoxysilane, propyltrimethoxysilane, propylmethyldimethoxysilane, Examples thereof include propylmethyldiethoxysilane.

When manufacturing the said polysiloxane, you may use a solvent as needed. The solvent is not particularly limited, but specifically, aliphatic hydrocarbon solvents such as pentane, hexane, heptane, decane, ether solvents such as diethyl ether, tetrahydrofuran, 1,4-dioxane, formamide, dimethylformamide, N -Amide type solvents such as methylpyrrolidone, aromatic hydrocarbon type solvents such as benzene, toluene and xylene, and alcohol type solvents such as methanol, ethanol and propanol.
Moreover, when manufacturing the said polysiloxane, you may use a catalyst as needed. The catalyst is not particularly limited, and specifically, acidic catalysts such as hydrochloric acid and acetic acid, Lewis acid catalysts such as ammonium fluoride, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium acetate, potassium acetate, sodium bicarbonate, Examples thereof include alkali metal salts such as potassium carbonate, potassium hydrogen carbonate, calcium carbonate, sodium methoxide and sodium ethoxide, and amine compounds such as triethylamine, tributylamine, pyridine and 4-dimethylaminopyridine.

  As an organosilicon compound used in producing the polysiloxane, a silane coupling agent having a mercapto group [for example, an organosilicon compound represented by the formula (7)] and a silane coupling having a sulfide group or a mercapto group When a silane coupling agent other than the agent [for example, an organosilicon compound represented by formula (6) or formula (8)] is used in combination, a silane coupling agent having a mercapto group and a silane cup having a sulfide group or mercapto group The mixing ratio (molar ratio) with a silane coupling agent other than a ring agent (a silane coupling agent having a mercapto group / a silane coupling agent other than a silane coupling agent having a sulfide group or a mercapto group) is an effect of the present invention. Is more preferably 1.1 / 8.9 to 6.7 / 3.3. And more preferably in the range of 1.4 / 8.6 to 5.0 / 5.0.

  As the organosilicon compound used in producing the polysiloxane, a silane coupling agent having a mercapto group [for example, an organosilicon compound represented by the formula (7)] and a silane coupling agent having a sulfide group [for example, , An organosilicon compound represented by the formula (5)], in combination, a mixing ratio (molar ratio) of a silane coupling agent having a mercapto group and a silane coupling agent having a sulfide group (a silane cup having a mercapto group) The ring agent / silane coupling agent having a sulfide group) is preferably 2.0 / 8.0 to 8.9 / 1.1 because the effect of the present invention is more excellent, and 2.5 / 7. More preferably, it is from 5 to 8.0 / 2.0.

  As the organosilicon compound used in producing the polysiloxane, a silane coupling agent having a mercapto group [for example, an organosilicon compound represented by the formula (7)], a silane coupling agent having a sulfide group [for example, , An organosilicon compound represented by formula (5) and / or], and a silane coupling agent other than a silane coupling agent having a sulfide group or a mercapto group [for example, represented by formula (6) or formula (8) When the organosilicon compound] is used in combination, the amount of the silane coupling agent having a mercapto group is preferably 10.0 to 73.0% in the total amount (mol) of the former three. The amount of the silane coupling agent having a sulfide group is preferably 5.0 to 67.0% of the total amount of the former three. The amount of the silane coupling agent other than the silane coupling agent having a sulfide group or mercapto group is preferably 16.0 to 85.0% in the total amount of the former three.

  In the composition of the present invention, the content of the mercapto silane coupling agent is 1 to 15 parts by mass with respect to 100 parts by mass of the diene rubber. Especially, it is preferable that it is 5-13 mass parts from the reason which the effect of this invention is more excellent.

  In the composition of the present invention, the content of the mercapto silane coupling agent is preferably 2 to 18% by mass and more preferably 5 to 12% by mass with respect to the content of silica.

  In addition, a mercapto type | system | group silane coupling agent may be used individually by 1 type, and may use 2 or more types together.

[Cationic surfactant]
The cationic surfactant (cationic surfactant) contained in the composition of the present invention is an amide bond (—NR—CO—, where R represents a hydrogen atom or a substituent (preferably a hydrocarbon group)). Alternatively, it is a quaternary ammonium salt (specific cationic surfactant) having a carboxylic ester bond (—O—CO—). Among these, a quaternary ammonium salt having an amide bond is preferable because the effect of the present invention is more excellent. The quaternary ammonium salt is preferably a salt of a quaternary ammonium ion and a halide ion (fluoride ion, chloride ion, bromide ion, iodide ion, etc.).
In the present specification, the cationic surfactant is a surfactant having only a cationic (cationic) dissociating group as a dissociating group, and a cationic (cationic) dissociating group and an anion as dissociating groups. So-called amphoteric surfactants having both sex (anionic) dissociating groups are not included.

<Quaternary ammonium salt having an amide bond>
The number of amide bonds contained in the quaternary ammonium salt having an amide bond is preferably 2 or more and 4 or less from the viewpoint of silica adsorption and silica dispersibility.

  As a suitable aspect of the quaternary ammonium salt having the amide bond, for example, a compound represented by the following formula (P1) can be mentioned.

In the above formula (P1), R ¹ represents a hydrocarbon group having 1 to 8 carbon atoms or a group represented by the following formula (P2), R ² represents an alkylene group, R ³ represents an acyl group, R ⁴ represents a methyl group, an ethyl group or a benzyl group, X represents a halogen atom, and m represents a number of 1 to 3.

In the above formula (P2), ^{R 5} represents a hydrogen atom or an acyl group, ^{R 6} represents a hydrogen atom or a methyl radical, n represents a number of 1-3.

In the above formula (P1), R ¹ represents a hydrocarbon group having 1 to 8 carbon atoms or a group represented by the above formula (P2). Examples of the hydrocarbon group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, secondary butyl group, t-butyl group, pentyl group, isopentyl group, and secondary pentyl group. T-pentyl group, hexyl group, secondary hexyl group, heptyl group, secondary heptyl group, octyl group, secondary octyl group, 2-methylpentyl group, 2-ethylhexyl group, vinyl group, allyl group, propenyl group, Examples include butenyl group, isobutenyl group, pentenyl group, isopentenyl group, hexenyl group, heptenyl group, octenyl group, cyclohexyl group, phenyl group, methylphenyl group, and benzyl group.

In the above formula (P2), R ⁵ represents a hydrogen atom or an acyl group. In the present invention, an acyl group refers to a residue obtained by removing OH from a monovalent carboxylic acid. Such carboxylic acids include acetic acid, propionic acid, butanoic acid, pentanoic acid, isopentanoic acid, caproic acid (hexanoic acid), heptanoic acid, caprylic acid (octanoic acid), nonanoic acid, capric acid (decanoic acid), lauric acid Saturated fatty acids such as acids (undecanoic acid), myristic acid (tetradecanoic acid), palmitic acid (hexadecanoic acid), stearic acid (octadecanoic acid), arachidic acid (eicosanoic acid), behenic acid (docosanoic acid), tetracosanoic acid, hexacosanoic acid Unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, elaidic acid and erucic acid; hydroxy fatty acids such as ricinoleic acid and hydroxystearic acid;

In the above formula (P2), R ⁶ represents a hydrogen atom or a methyl group, and n represents a number of 1 to 3 (preferably an integer of 1 to 3). R ⁶ is preferably a hydrogen atom and n is preferably 1 because of its superior adsorptivity to silica.

In the above formula (P1), R ¹ is preferably a methyl group or an ethyl group, and more preferably a methyl group, from the viewpoint of adsorptivity to silica.

In the above formula (P1), R ² represents an alkylene group. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a hexamethylene group, an octamethylene group, and the like. Since the adsorbability to silica is excellent and the industrial availability of the raw material is easy, R ² is ethylene. Group and propylene group are preferred.

In the above formula (P1), R ³ represents an acyl group, and examples of the carboxylic acid corresponding to the acyl group include the carboxylic acids exemplified for R ⁵ in the above formula (P2). From the standpoints of adsorptivity to silica and silica dispersibility, fatty acids having 8 to 22 carbon atoms are preferred, and fatty acids having 10 to 18 carbon atoms are more preferred. R ⁴ represents a methyl group, an ethyl group or a benzyl group, and is preferably a methyl group from the viewpoint of adsorptivity to silica. X represents a halogen atom, and examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom. X is preferably a chlorine atom from the viewpoint of adsorptivity to silica. m represents a number of 1 to 3 (preferably an integer of 1 to 3), and m is preferably 2 from the viewpoint of adsorption to silica and dispersibility of silica. In the case where a plurality of acyl groups are present in the compound represented by the formula (P1), they may be the same group or different groups.

<Quaternary ammonium salt having carboxylate bond>
The number of carboxylic acid ester bonds of the quaternary ammonium salt having a carboxylic acid ester bond is preferably 2 or more and 4 or less from the viewpoint of silica adsorption and silica dispersibility.

  As a suitable aspect of the quaternary ammonium salt having a carboxylic acid ester bond, for example, a compound represented by the following formula (Q1) can be mentioned.

In the above formula (Q1), ^{R 1} represents a hydrocarbon group having 1 to 8 carbon atoms, ^{R 2} represents an alkylene group, ^{R 3} represents an acyl group, ^{R 4} is a methyl group, an ethyl group or a benzyl group X represents a halogen atom, and m represents a number of 1 to 3.

In the above formula (Q1), R ¹ represents a hydrocarbon group having 1 to 8 carbon atoms. Specific examples of the hydrocarbon group having 1 to 8 carbon atoms are the same as R ¹ in formula (P1) described above. R ¹ is preferably a methyl group or an ethyl group, and more preferably a methyl group, from the viewpoint of adsorptivity to silica.

In the above formula (Q1), R ² represents an alkylene group. Specific examples and preferred embodiments of R ² is the same as R ² in the above-mentioned formula (P1).

In the above formula (Q1), R ³ represents an acyl group, and examples of the carboxylic acid corresponding to the acyl group include the carboxylic acids exemplified for R ⁵ in the above formula (P2). From the standpoints of adsorptivity to silica and silica dispersibility, fatty acids having 8 to 22 carbon atoms are preferred, and fatty acids having 10 to 18 carbon atoms are more preferred. R ⁴ represents a methyl group, an ethyl group or a benzyl group, and is preferably a methyl group from the viewpoint of adsorptivity to silica. X represents a halogen atom, and examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom. X is preferably a chlorine atom from the viewpoint of adsorptivity to silica. m represents a number of 1 to 3 (preferably an integer of 1 to 3), and m is preferably 2 from the viewpoint of adsorption to silica and dispersibility of silica. In the case where a plurality of acyl groups are present in the compound represented by the formula (Q1), they may be the same group or different groups.

  In the composition of the present invention, the content of the specific cationic surfactant is 0.05 to 10 parts by mass with respect to 100 parts by mass of the diene rubber described above. It is preferable that it is 0.1-5 mass parts. In addition, a specific cationic surfactant may be used individually by 1 type, and may use 2 or more types together.

[Optional ingredients]
<Glycerin partial fatty acid ester>
It is preferable that the composition of this invention contains glycerol partial fatty acid ester with the specific cationic surfactant mentioned above from the reason which the effect of this invention is more excellent. Since the glycerin partial fatty acid ester improves the dispersibility of the specific cationic surfactant, as a result, the dispersibility of the silica is further increased, and the above-described effects of the present invention are further improved. In the present invention, the partial fatty acid ester refers to a compound in which a part of hydroxyl groups of a polyhydric alcohol is esterified with a fatty acid, and the glycerin partial fatty acid ester includes glycerin monofatty acid ester and glycerin difatty acid ester. .

Examples of the fatty acid of the glycerin partial fatty acid ester include the carboxylic acids exemplified for R ⁵ in the above-described formula (P2). From the viewpoint of silica dispersibility, saturated fatty acids having 14 to 24 carbon atoms are preferable, and 16 to 22 saturated fatty acids are more preferred and stearic acid is most preferred. One type of fatty acid may be used alone, or two or more types may be used in combination, but when two or more types of fatty acids are used, one of them is preferably stearic acid.

  The glycerin partial fatty acid ester is preferably a glycerin monofatty acid ester from the viewpoint of dispersibility of silica. In the case of a mixture of glycerin monofatty acid ester and glycerin difatty acid ester, the content of glycerin monofatty acid ester is at least 50% by mass. It is preferable that

In the composition of the present invention, the ratio of the content of the specific cationic surfactant described above with respect to the content of the glycerin partial fatty acid ester (specific cationic surfactant / glycerin partial fatty acid ester) is 0.01 to 10, preferably 0.1 to 1.0, and more preferably 0.2 to 0.5.
Moreover, it is preferable that it is 0.1-10 mass parts with respect to 100 mass parts of diene rubbers mentioned above, and, as for content of glycerol partial fatty acid ester, it is more preferable that it is 1-5 mass parts. Moreover, it is preferable that content of the sum total of the specific cationic surfactant mentioned above and glycerol partial fatty acid ester is 0.2-10 mass parts with respect to 100 mass parts of diene rubbers mentioned above. A glycerol partial fatty acid ester may be used individually by 1 type, and may use 2 or more types together.

(Fatty acid metal salt)
The composition of the present invention preferably contains a fatty acid metal salt together with the specific cationic surfactant described above for the reason that the effects of the present invention are more excellent. Since the fatty acid metal salt improves the dispersibility of the specific cationic surfactant, as a result, the dispersibility of the silica is further increased, and the above-described effects of the present invention are further improved.

The fatty acid metal salt is a salt of a fatty acid and a metal.
Examples of the fatty acid of the fatty acid metal salt include carboxylic acids exemplified as R ⁵ in the formula (P2). From the viewpoint of dispersibility of silica, a saturated fatty acid having 8 to 24 carbon atoms is preferable, and a carbon atom having 10 to 22 carbon atoms is preferable. Saturated fatty acids are more preferred, saturated fatty acids having 16 to 22 carbon atoms are more preferred, and behenic acid is most preferred. A fatty acid may be used individually by 1 type, and may use 2 or more types together.
Examples of the metal of the fatty acid metal salt include alkali metals, alkaline earth metals, transition metals (groups 3 to 11 metals), aluminum, germanium, tin, antimony and the like. Among them, alkali metals (lithium, potassium, Sodium), alkaline earth metals (beryllium, magnesium, calcium, strontium, barium, etc.) and the like. From the viewpoint of silica dispersibility, alkali metals and alkaline earth metals are more preferred, and alkaline earth metals are further preferred. Magnesium is preferred and most preferred.
Specific examples of preferable fatty acid metal salts include potassium stearate, zinc stearate, magnesium stearate, magnesium oleate, magnesium palmitate, magnesium myristate, magnesium laurate, magnesium linoleate, and magnesium behenate.

  In the composition of the present invention, the ratio of the content of the specific cationic surfactant described above to the content of the fatty acid metal salt (specific cationic surfactant / fatty acid metal salt) is 0.01 to 10 by mass ratio. It is preferable that it is 0.1 to 1.0. Moreover, it is preferable that it is 0.1-10 mass parts with respect to 100 mass parts of diene rubbers mentioned above, and, as for content of a fatty-acid metal salt, it is more preferable that it is 0.5-5 mass parts. The total content of the specific cationic surfactant and the fatty acid metal salt is preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the diene rubber. A fatty acid metal salt may be used individually by 1 type, and may use 2 or more types together.

  The composition of the present invention preferably contains both the glycerin partial acid ester and the fatty acid metal salt together with the specific cationic surfactant described above for the reason that the effects of the present invention described above are further excellent.

(Other additives)
If necessary, the composition of the present invention may further contain an additive within a range not impairing its effects and purposes.
Examples of the additive include fillers other than silica (for example, carbon black), silane coupling agents having no mercapto group, zinc oxide (zinc white), stearic acid, anti-aging agent, processing aid, process Various additives generally used in rubber compositions such as oil, aroma oil, liquid polymer, terpene resin, thermosetting resin, vulcanizing agent (for example, sulfur), and vulcanization accelerator can be used.

<Method for producing rubber composition for tire>
The production method of the composition of the present invention is not particularly limited, and specific examples thereof include, for example, kneading the above-described components using a known method and apparatus (for example, a Banbury mixer, a kneader, a roll, etc.). The method etc. are mentioned. When the composition of the present invention contains sulfur or a vulcanization accelerator, it is preferable to mix components other than sulfur and the vulcanization accelerator first, cool the mixture, and then mix the sulfur or vulcanization accelerator. .
The composition of the present invention can be vulcanized or crosslinked under conventionally known vulcanization or crosslinking conditions.

[tire]
The tire (pneumatic tire) of the present invention is a tire manufactured using the above-described composition of the present invention. Especially, it is preferable that it is a tire which used the composition of this invention for the tread part (tire tread).
FIG. 1 shows a schematic partial sectional view of a tire representing an example of an embodiment of the tire of the present invention, but the tire of the present invention is not limited to the embodiment shown in FIG.

In FIG. 1, reference numeral 1 represents a bead portion, reference numeral 2 represents a sidewall portion, and reference numeral 3 represents a tire tread portion.
Further, a carcass layer 4 in which fiber cords are embedded is mounted between the pair of left and right bead portions 1, and the end of the carcass layer 4 extends from the inside of the tire to the outside around the bead core 5 and the bead filler 6. Wrapped and rolled up.
In the tire tread 3, a belt layer 7 is disposed over the circumference of the tire on the outside of the carcass layer 4.
Moreover, in the bead part 1, the rim cushion 8 is arrange | positioned in the part which touches a rim | limb.

  The tire of the present invention can be manufactured, for example, according to a conventionally known method. Moreover, as gas with which a tire is filled, inert gas, such as nitrogen, argon, helium other than the air which adjusted normal or oxygen partial pressure, can be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.

[Preparation of rubber composition for tire]
The components shown in Table 1 below were blended in the proportions (parts by mass) shown in the same table.
Specifically, first, components other than sulfur and a vulcanization accelerator among the components shown in the same table were mixed for 5 minutes using a 1.7 liter closed Banbury mixer. The temperature at the time of discharge was 152 ° C., and it was cooled to room temperature to obtain a master batch. Further, using the above Banbury mixer, sulfur and a vulcanization accelerator were mixed for 3 minutes with the obtained master batch and released at 110 ° C. to obtain a tire rubber composition.
In Table 1, for the amount of SBR, the upper value is the amount of SBR (oil-extended product) (unit: parts by mass), and the lower value is the net amount of SBR contained in SBR (unit: parts by mass). is there.

[Evaluation]
The following evaluation was performed about the obtained rubber composition for tires.

<Extrudability>
The obtained tire rubber composition (unvulcanized) was mixed with an open roll for a certain period of time, and then taken out in a sheet form to a thickness of 5 mm, and then the sheet thickness immediately after and the sheet thickness after standing for 1 day were measured. The amount of change (shrink amount) was obtained. Table 1 shows the reciprocal of the amount of change (extrusion processability). The results were expressed as an index with the reciprocal of the amount of change in Comparative Example 1 as 100. The larger the index, the smaller the shrink and the better the extrudability.

<Scorch resistance>
About the obtained tire rubber composition (unvulcanized), the scorch time was measured under the condition of a test temperature of 125 ° C. using an L-shaped rotor in accordance with JIS K6300-1: 2013. Table 1 shows the scorch time (scorch resistance). The results were expressed as an index with the scorch time of Comparative Example 1 as 100. The larger the index, the longer the scorch time and the better the scorch resistance.

<Tan δ (60 ° C.)>
The obtained tire rubber composition (unvulcanized) was press vulcanized at 160 ° C. for 20 minutes in a mold (15 cm × 15 cm × 0.2 cm) to produce a vulcanized rubber sheet.
About the produced vulcanized rubber sheet according to JISK6394: 2007, using a viscoelastic spectrometer (manufactured by Toyo Seiki Seisakusho Co., Ltd.) under the conditions of 10% ± 2% elongation deformation strain, frequency 20 Hz, temperature 60 ° C. , Tan δ (60 ° C.) was measured.
tan δ (60 ° C.) is shown in Table 1 (tan δ (60 ° C.)). The results were expressed as an index with tan δ (60 ° C.) of Comparative Example 1 as 100. The smaller the index, the smaller the tan δ (60 ° C.) and the better the fuel efficiency.

The details of each component in Table 1 are as follows.
-SBR: E580 manufactured by Asahi Kasei Chemicals Corporation, oil-extended product (including 37.5 parts by mass of oil-extended oil with respect to 100 parts by mass of SBR. The net of SBR in SBR is 72.7% by mass)
-BR: Nipol BR 1220 manufactured by Nippon Zeon
Silica: Zeosil 1205MP (CTAB: 200 m ² / g) manufactured by Solvay
-Carbon black: Seast 7HM manufactured by Tokai Carbon
Silane coupling agent 1: VP Si363 (manufactured by Evonik Degussa) (compound represented by the formula (A1) described above. Here, R ¹¹ : —OC ₂ H ₅ , R ¹² : —O (C ₂ H) _{4 O) 5 -C 13 H 27} , R 14 :-( CH 2) 3 -, l = 1, m = 2, n = 0).
Silane coupling agent 2: NXT-Z45 (manufactured by Momentive Co.) (a copolymer having a repeating unit represented by the above-described formula (A3) and a repeating unit represented by the above-described formula (A4))
Silane coupling agent 3: polysiloxane synthesized as follows (polysiloxane represented by the average formula of the above-described formula (1))
A 2 L separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 107.8 g (0.2 mol) of bis (triethoxysilylpropyl) tetrasulfide (KBE-846 manufactured by Shin-Etsu Chemical Co., Ltd.), γ-mercapto. Contains 95.4 g (0.4 mol) of propyltriethoxysilane (KBE-803, Shin-Etsu Chemical Co., Ltd.), 442.4 g (1.6 mol) of octyltriethoxysilane (KBE-3083, Shin-Etsu Chemical Co., Ltd.), and 162.0 g of ethanol. Thereafter, a mixed solution of 0.5N hydrochloric acid 32.4 g (1.8 mol) and ethanol 75.6 g was added dropwise at room temperature. Then, it stirred at 80 degreeC for 2 hours. Thereafter, filtration, 14.6 g of a 5% KOH / EtOH solution was added dropwise, and the mixture was stirred at 80 ° C. for 2 hours. Then, 425.4 g of polysiloxane of brown transparent liquid was obtained by concentration under reduced pressure and filtration. As a result of measurement by GPC, the average molecular weight was 860, and is represented by the following average composition formula.
_{(-C 3 H 6 -S 4 -C} 3 H 6 -) 0.083 (-C 8 H 17) 0.667 (-OC 2 H 5) 1.50 (-C 3 H 6 SH) 0.167 SiO _0.75
Comparative silane coupling agent: Si69 (bis (3-triethoxysilylpropyl) tetrasulfide, manufactured by Evonik Degussa)
Cationic surfactant 1: structure shown below (wherein R ³ represents an acyl group derived from decanoic acid (capric acid))

Cationic surfactant 2: Structure shown below (wherein R ³ represents an acyl group derived from a mixed fatty acid (lauric acid / oleic acid = 2/1 (mass ratio))

Fatty acid metal salt: magnesium behenate (magnesium content 3.4% by mass)
-Glycerin partial fatty acid ester: Glycerin monostearate ester-Zinc flower: Zinc oxide 3 types of zinc oxide-Anti-aging agent: Santoflex 6PPD (manufactured by Solusia Europe)
・ Stearic acid: Industrial stearic acid N manufactured by Chiba Fatty Acid Co., Ltd.
・ Sulfur: Oil treatment sulfur manufactured by Hosoi Chemical Co., Ltd. ・ CBS: Noxeller CZ-G manufactured by Ouchi Shinsei Chemical Co.
-DPG: Ouchi Shinsei Chemical Industry Noxeller D
・ TBzTD: Sunseller TBZTD made by Sanshin Chemical Industry Co., Ltd.

As can be seen from Table 1, Examples 1 to 7 in which the mercapto silane coupling agent and the specific cationic surfactant are used in combination exhibited excellent extrudability and scorch resistance.
From the comparison between Examples 1 to 3 and 4 to 6, Examples 1 to 3 in which the specific cationic surfactant is a quaternary ammonium salt having an amide bond have better extrudability and excellent fuel efficiency. Indicated.
From the comparison between Examples 1 and 2 and the comparison between Examples 4 and 5, the mercapto-based silane coupling agent has a repeating unit represented by the formula (A3) and a repeating unit represented by the following formula (A4). Examples 2 and 5, which are copolymers, have better scorch resistance and better fuel efficiency.

  On the other hand, in Comparative Examples 1 to 5 in which the mercapto-based silane coupling agent and the specific cationic surfactant are not used in combination, at least one of extrusion processability and scorch resistance is insufficient.

1 Bead part 2 Side wall part 3 Tire tread part 4 Carcass layer 5 Bead core 6 Bead filler 7 Belt layer 8 Rim cushion

Claims (4)

Containing a diene rubber, silica, a silane coupling agent having a mercapto group, and a cationic surfactant,
The cationic surfactant is a quaternary ammonium salt having an amide bond or a carboxylic acid ester bond;
The silica content is 50 to 200 parts by mass with respect to 100 parts by mass of the diene rubber.
The content of the silane coupling agent is 1 to 15 parts by mass with respect to 100 parts by mass of the diene rubber,
The rubber composition for tires whose content of the said cationic surfactant is 0.05-10 mass parts with respect to 100 mass parts of said diene rubbers. The silane coupling agent is a copolymer having a compound represented by the following formula (A1), a repeating unit represented by the following formula (A3) and a repeating unit represented by the following formula (A4), or The rubber composition for tires according to claim 1, which is a polysiloxane represented by an average formula of formula (1).
In formula (A1), R ¹¹ represents an alkoxy group having 1 to 8 carbon atoms. R ¹² represents a linear polyether group having 4 to 30 carbon atoms. R ¹³ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R ¹⁴ represents an alkylene group having 1 to 30 carbon atoms. l represents an integer of 1 to 2, m represents an integer of 1 to 2, n represents an integer of 0 to 1, and l, m, and n satisfy the relational expression of l + m + n = 3. A plurality of R ^{11 s} when l is 2 may be the same or different, and a plurality of R ^{12 s} when m is 2 may be the same or different.
In formulas (A3) and (A4), R ³¹ and R ⁴¹ each independently represent an alkylene group having 1 to 5 carbon atoms.
R ³² and R ⁴² are each independently a linear or branched alkylene group having 1 to 30 carbon atoms, a linear or branched alkenylene group having 2 to 30 carbon atoms, or a linear or branched group. Represents a alkynylene group having 2 to 30 carbon atoms. When R ³² is a terminal, R ³² is a hydrogen atom, a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, or a straight chain. A chain or branched alkynyl group having 2 to 30 carbon atoms is represented. When R ⁴² is a terminal, R ⁴² is a hydrogen atom, a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, or a straight chain. A chain or branched alkynyl group having 2 to 30 carbon atoms is represented.
R ³³ and R ⁴³ each independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, A linear or branched alkynyl group having 2 to 30 carbon atoms, a linear or branched alkyl group having 1 to 30 carbon atoms and having a hydroxyl group or a carboxyl group at the terminal, or linear or branched A alkenyl group having 2 to 30 carbon atoms and having a hydroxyl group or a carboxyl group at its terminal.
R ³² and R ³³ may form a ring with R ³² and R ³³ .
R ⁴² and R ⁴³ may form a ring with R ⁴² and R ⁴³ .
R ³⁴ represents an alkyl group having 1 to 13 carbon atoms.
A plurality of R ³¹ , R ³² , R ³³ , R ³⁴ , R ⁴¹ , R ⁴² and R ⁴³ may be the same or different.
_{(A) a (B) b} (C) c (D) d (R 1) e SiO (4-2a-b-c-d-e) / 2 (1)
In formula (1), A represents a divalent organic group containing a sulfide group. B represents a monovalent hydrocarbon group having 5 to 20 carbon atoms. C represents a hydrolyzable group. D represents an organic group containing a mercapto group. R ¹ represents a monovalent hydrocarbon group having 1 to 4 carbon atoms. a to e satisfy the relational expressions of 0 <a <1, 0 <b <1, 0 <c <3, 0 <d <1, 0 ≦ e <2, and 0 <2a + b + c + d + e <4. The rubber composition for tires according to claim 1 or 2 whose CTAB adsorption specific surface area of said silica is 140-300 m < ² > / g.   The tire manufactured using the rubber composition for tires of any one of Claims 1-3.