JP2013224407A - Rubber composition for tire, and tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition for a tire, which is good in processability, and is capable of being improved in braking performance on a wet road surface without spoiling rolling resistance of the tire; and to provide a tire using the rubber composition, and being improved in braking performance on a wet road surface without spoiling rolling resistance.SOLUTION: A rubber composition for a tire contains at least one rubber component (A) selected from dienic synthetic rubbers and natural rubbers, silica (B), at least one compound (C) selected from the group consisting of compounds represented by formula (1), and a silane coupling agent (D), wherein the blend amount of the silica (B) is 20 parts by mass to 120 parts by mass with respect to 100 parts by mass of the rubber component (A); the mass ratio (represented by [a blend amount of (C)/a blend amount of (B)]) of the blend amount of the compound (C) to the blend amount of the silica (B) is 0.001 to 0.5.

Description

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

  Recently, from the viewpoint of vehicle safety, there is a demand for further improving the braking performance on wet road surfaces of tires. In addition, from the viewpoint of reducing carbon dioxide emissions due to increased concern about environmental issues, there is an increasing demand for lower fuel consumption of vehicles. To meet these demands, rolling resistance is reduced as much as possible. Small tires are needed.

  In response to these requirements, a technique using silica as a filler for a rubber composition used for a tire tread is effective as a conventional technique for achieving both improvement in performance on a wet road surface of a tire and reduction in rolling resistance. It is known (Patent Document 1). Moreover, as another prior art for achieving the said objective, raising the glass transition temperature of the rubber component of the rubber composition used for the tread of a tire is known (patent document 2).

  However, a rubber composition in which silica is blended with a rubber component has a high unvulcanized viscosity and requires multi-stage kneading, so that its processing is difficult. In addition, even if the blending amount of silica contained in the rubber composition is increased in order to further improve the performance, although the braking performance of the wet road surface is improved, the rolling resistance is increased and the workability is remarkably deteriorated.

  Further, as described above, even if the glass transition temperature is further increased to improve the performance, the braking performance of the wet road surface is improved, but other performance such as rolling resistance is deteriorated.

Japanese Patent Application Laid-Open No. 2011-213988 Special table 2010-526924

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and provides a tire rubber composition capable of improving the braking performance on a wet road surface without impairing the rolling resistance of the tire as well as good processability. It is to provide. Another object of the present invention is to provide a tire using the rubber composition and having improved braking performance on a wet road surface without impairing rolling resistance.

  As a result of intensive investigations to achieve the above object, the present inventor has found that a specific amount of silica, a specific type and a specific amount of a compound with respect to at least one rubber component selected from diene-based synthetic rubber and natural rubber It was found that a rubber composition capable of improving the braking performance on a wet road surface without impairing the rolling resistance of the tire can be obtained by blending with the present invention, and the present invention has been completed. .

［式中、Ｒ^１は炭素数１〜４のアルキレン基または置換基として炭素数１〜１０のアルキル基を有してもよいアリーレン基、Ｒ^２は水素原子またはメチル基、Ｒ^３，Ｒ^４及びＲ^５は水素原子、炭素数１〜１８のアルキル基または炭素数２〜４のアルカノール基を示し、Ａ^１は炭素数４〜１２のアルキレン基、Ａ^２は炭素数２または３のアルキレン基を表し、ｎは０〜２０の整数であり、ｍは１〜５０の整数である］で表される化合物からなる群から選択される少なくとも一種の化合物（Ｃ）と、シランカップリング剤（Ｄ）とを含むタイヤ用ゴム組成物であって、前記シリカ（Ｂ）の配合量が、前記ゴム成分（Ａ）１００質量部に対して２０質量部〜１２０質量部であり、前記化合物（Ｂ）の配合量に対する前記化合物（Ｃ）の配合量の質量比（［（Ｃ）の配合量／（Ｂ）の配合量］で表す）が、０．００１〜０．５であることを特徴とする。かかるゴム組成物は、加工性が良好な上、タイヤの転がり抵抗を損なうことなく湿潤路面における制動性を向上させることができる。 That is, the tire rubber composition of the present invention comprises at least one rubber component (A) selected from diene-based synthetic rubber and natural rubber, silica (B), and the following general formula (1):

[Wherein, R ¹ is an alkylene group having 1 to 4 carbon atoms or an arylene group which may have an alkyl group having 1 to 10 carbon atoms as a substituent, R ² is a hydrogen atom or a methyl group, R ³ , R ⁴ And R ⁵ represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms or an alkanol group having 2 to 4 carbon atoms, A ¹ is an alkylene group having 4 to 12 carbon atoms, and A ² is an alkylene group having 2 or 3 carbon atoms. Wherein n is an integer of 0 to 20, and m is an integer of 1 to 50], and at least one compound (C) selected from the group consisting of compounds represented by: And the compounding amount of the silica (B) is 20 parts by mass to 120 parts by mass with respect to 100 parts by mass of the rubber component (A), and the compound (B) Compounding amount of the compound (C) with respect to the compounding amount of Weight ratio (expressed in [(C) of the amount / (amount of B)]), characterized in that 0.001 to 0.5. Such a rubber composition has good processability and can improve the braking performance on wet road surfaces without impairing the rolling resistance of the tire.

  In the rubber composition of this invention, it is preferable that the compounding quantity of the said compound (C) is 0.1 mass part-30 mass parts with respect to 100 mass parts of said rubber components (A). By being in the above range, a synergistic effect for improving braking performance on a wet road surface can be advantageously obtained without wasting both components.

  In the rubber composition of the present invention, the mass ratio of the compounding amount of the silane coupling agent (D) to the compounding amount of the silica (B) ([the compounding amount of (D) / the compounding amount of (B)] is represented. ) Is preferably 0.05 to 0.15. By setting it as the said range, rolling resistance can be reduced more, without workability deteriorating significantly.

In the rubber composition of the present invention, the silane coupling agent (D) is represented by the following general formula (2) from the viewpoints of processability and wear resistance:
_{^{R 1 x R 2 y R 3}} z Si-R 4 -S-CO-R 5 ··· (2)
[Wherein R ¹ represents 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 ) _n (OSiR ⁵ R ⁶ R ⁷ ) and having 1 to 18 carbon atoms (provided that R ⁶ and R ⁷ are each independently an alkyl group, a cycloalkyl group, an alkenyl group, a cyclo Selected from alkenyl groups and aryl groups, and having 1 to 18 carbon atoms and n being 0 to 10); R ² is hydrogen or an alkyl group, cycloalkyl group or alkenyl group having 1 to 18 carbon atoms; R ³ is — [O (R ⁸ O) m] _0.5 — (wherein R ⁸ is selected from an alkylene group and a cycloalkylene group, and has a carbon number of 1-18 and m is 1-4) x, y and z is, x + y + 2z = 3,0 ≦ x ≦ 3,0 ≦ y ≦ 2,0 satisfy the relationship ≦ z ≦ 1; ^{R 4} is an alkylene group, cycloalkylene group, cycloalkylalkylene group, alkenylene Selected from a group, an arylene group and an aralkylene group and having 1 to 18 carbon atoms; R ⁵ is selected from an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group and an aralkyl group; The number is 1-18. It is preferably at least one selected from the group consisting of compounds represented by

  In the rubber composition of the present invention, from the viewpoint of solubility in rubber, n in the above formula (1) is an integer of 0 to 20, m is preferably an integer of 1 to 30, and In formula (1), n is an integer of 0 to 10, and m is more preferably an integer of 1 to 20.

  In the rubber composition of the present invention, the rubber component (A) preferably contains 50% by mass to 100% by mass of styrene-butadiene copolymer rubber (SBR) from the viewpoint of braking performance on a wet road surface.

  Furthermore, the tire of the present invention is characterized in that the rubber composition is used as a constituent member, particularly a tread. A tire including a constituent member using the rubber composition is more excellent in braking performance on a wet road surface without impairing rolling resistance.

  ADVANTAGE OF THE INVENTION According to this invention, the rubber composition which can improve the braking performance in a wet road surface without impairing the rolling resistance of a tire can be provided while processability is favorable. Further, a tire having improved braking performance on a wet road surface can be provided using the rubber composition without impairing rolling resistance.

Hereinafter, the present invention will be described in detail by illustrating its embodiments. The rubber composition for tires of the present invention comprises at least one rubber component (A) selected from diene-based synthetic rubber and natural rubber, silica (B), and a compound represented by the above general formula (1). A tire rubber composition comprising at least one compound (C) selected from the group and a silane coupling agent (D),
The compounding amount of the silica (B) with respect to 100 parts by mass of the rubber component (A) is 20 parts by mass to 120 parts by mass, and the mass ratio of the compounding amount of the compound (C) with respect to the compounding amount of the silica (B) is. It is 0.001-0.5.

[Rubber component (A)]
The rubber composition of the present invention contains at least one selected from diene synthetic rubber and natural rubber as the rubber component (A). Examples of the diene-based synthetic rubber include polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), butyl rubber (IIR), halogenated butyl rubber, ethylene-propylene-diene rubber (EPDM), Examples include chloroprene rubber (CR) and acrylonitrile-butadiene rubber (NBR). Among these, styrene-butadiene copolymer rubber is preferable, and in particular, the rubber component (A) more preferably contains 50% by mass to 100% by mass of styrene-butadiene copolymer rubber. By using styrene-butadiene copolymer rubber (SBR) as the rubber component (A), the braking performance on the wet road surface can be maintained well. In addition, these rubber components may be used independently and may use 2 or more types.

[Silica (B)]
The rubber composition of the present invention contains silica (B) as a filler. The compounding amount of the silica (B) needs to be in the range of 20 parts by mass to 120 parts by mass with respect to 100 parts by mass of the rubber component (A), and is in the range of 30 parts by mass to 100 parts by mass. It is more preferable, and it is especially preferable that it is the range of 40 mass parts-80 mass parts. When the blending amount of the silica (B) is less than 20 parts by mass with respect to 100 parts by mass of the rubber component (A), the effect of reducing rolling resistance and the effect of improving braking performance on wet road surfaces are low, and 120 parts by mass. If it exceeds 1, the rolling resistance increases, the unvulcanized viscosity of the rubber composition increases, and the processability may decrease.

The silica (B) used in the rubber composition is not particularly limited, and examples thereof include wet silica (hydrous silicic acid), dry silica (anhydrous silicic acid), calcium silicate, aluminum silicate, and the like. Of these, wet silica is most preferred because it has the most remarkable effects of improving fracture resistance, braking performance on wet road surfaces, and low rolling resistance. Further, the silica (B) a nitrogen adsorption specific surface area by the BET method (compliant with ISO5794 / 1 measurement.) Is preferably a ^{100m 2 / g~270m 2 / g,} 170m 2 / g~270m 2 / G is particularly preferable. If the nitrogen adsorption specific surface area of silica (B) is in the above range, there is an advantage that both rubber reinforcement and dispersibility in the rubber component can be achieved.

  Examples of commercially available silica that can be used in the present invention include nip seal AQ (manufactured by Nippon Silica Industry Co., Ltd.), nip seal KQ (manufactured by Nippon Silica Industry Co., Ltd.), and Ultrasil VN3 (manufactured by Degussa). In addition, these silicas may be used independently and may use 2 or more types.

[Compound (C)]
Moreover, the rubber composition of this invention contains a compound (C). As said compound (C), at least 1 type selected from the group which consists of a compound represented by the said General formula (1) is used.

In the general formula (1), the alkylene group having 1 to 4 carbon atoms in R ¹ may be linear or branched, such as a methylene group, an ethylene group, various propanediyl groups, and the like. Various butanediyl groups can be mentioned. “Various” of various propanediyl groups and various butanediyl groups refers to groups including all isomers having the same carbon number. The same applies hereinafter.
On the other hand, examples of the arylene group which may have an alkyl group having 1 to 10 carbon atoms as a substituent in R ¹ include a phenylene group, various methylphenylene groups, various dimethylphenylene groups, and various naphthylene groups. Can do.

In the general formula (1), the alkyl group having 1 to 18 carbon atoms of R ³ , R ⁴ and R ⁵ may be linear, branched or cyclic, for example, a methyl group , Ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, various pentyl groups, various hexyl groups, various octyl groups, various decyl groups, various dodecyl groups, Examples include various tetradecyl groups, various hexadecyl groups, various octadecyl groups, cyclopentyl groups, cyclohexyl groups, and cyclooctyl groups.
Further, the alkanol group having 2 to 4 carbon atoms of R ³ , R ⁴ and R ⁵ may be either linear or branched, for example, 2-hydroxyethyl group, 2-hydroxypropyl Groups, 3-hydroxypropyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group.

In the general formula (1), the alkylene group having 4 to 12 carbon atoms represented by A ¹ may be linear or branched. In addition, A ¹ O in the general formula (1) can be introduced by addition reaction of various butylene oxides with the hydroxyl group of the compound having a hydroxyl group.

On the other hand, examples of the alkylene group having 2 or 3 carbon atoms represented by A ² include an ethylene group and an isopropylene group. Further, as the A ^{2 O} in the general formula (1), to the hydroxyl group of a compound having a hydroxyl group, by the addition reaction of ethylene oxide, it can be introduced oxyethylene group, by the addition reaction of propylene oxide An oxyisopropylene group can be introduced.

In the present invention, if the A 2 ^O there are a plurality, a plurality of A ^{2 O} may be identical to one another or may be different. The A ² O may have an oxyethylene group block portion and an oxyisopropylene group block portion, and a mixture of oxyethylene groups and oxyisopropylene groups randomly. Also good.
On the other hand, if the A 1 ^O there are multiple, multiple A ^{1 O} may be identical to one another or may be different.

Moreover, in the said General formula (1), n is an integer of 0-20, m is an integer of 1-50, However, n is an integer of 0-20 from a soluble viewpoint to rubber | gum, and m Is preferably an integer of 1 to 30, more preferably n is an integer of 0 to 10, and m is an integer of 1 to 20. The order of (A ¹ O) _n and (A ² O) _m is not particularly limited.

The compound represented by the general formula (1) can mainly function as an ionic surfactant. Moreover, there is no restriction | limiting in particular as a manufacturing method of the said compound, Although a conventionally well-known manufacturing method can be used, For example, this compound can be manufactured as follows.
H ₂ C═C (R ² ) —R ¹ —OH (R ¹ and R ² are as defined above), such as 3-methyl-3-buten-1-ol and allyl alcohol. In the presence of a catalyst, at least one selected from alkylene oxide, alkyl glycidyl ether, α-olefin epoxide and the like is added to a saturated alcohol to obtain an ether alcohol. Next, the compound of interest is obtained by sulfation using a sulfating agent and neutralization with a basic substance such as triethanolamine.
Examples of sulfating agents include chlorosulfonic acid, anhydrous sulfuric acid, amidosulfuric acid, etc., but suppress side reactions such as addition reaction of sulfuric acid group to double bond group and isomerization of double bond group. From the viewpoint, it is preferable to use amidosulfuric acid.

In the rubber composition of the present invention, the mass ratio of the compounding amount of the compound (C) to the compounding amount of the silica (B) (represented by [the compounding amount of (C) / the compounding amount of (B)] is It is necessary to be 0.001-0.5 (0.1 / 100-50 / 100), more preferably 0.001-0.4, and 0.001-0.3. Is particularly preferred. When the mass ratio of the blending amount is less than 0.001, the effect of improving the braking performance on a wet road surface is insufficient. On the other hand, when it exceeds 0.5, excessive gloss is generated due to blooming of the compound, and the outer surface. May deteriorate or workability may deteriorate due to problems in surface tackiness.
In addition, the said compound (C) may be used independently and may use 2 or more types.

  Moreover, in the rubber composition of this invention, it is preferable that the compounding quantity of the said compound (C) is 0.1 mass part-30 mass parts with respect to 100 mass parts of said rubber components (A). When the blending amount is 0.1 to 30 parts by mass with respect to the rubber component (A), the effect of improving the braking performance on the wet road surface can be advantageously obtained without wasting both components. .

[Silane coupling agent (D)]
Furthermore, the rubber composition of the present invention contains a silane coupling agent (D). The silane coupling agent (D) has the following general formula (2):
_{^{R 1 x R 2 y R 3}} z Si-R 4 -S-CO-R 5 ··· (2)
[In the formula (2), R ¹ represents 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 ) _n (OSiR ⁵ R ⁶ R ⁷ ) and having 1 to 18 carbon atoms (provided that R ⁶ and R ⁷ are each independently an alkyl group, a cycloalkyl group, an alkenyl group) R ² is selected from a group, a cycloalkenyl group and an aryl group and has 1 to 18 carbon atoms and n is 0 to 10); R ² is hydrogen, an alkyl group having 1 to 18 carbon atoms, or a cycloalkyl group , An alkenyl group, a cycloalkenyl group and an aryl group; R ³ is — [O (R ⁸ O) m] _0.5 — (wherein R ⁸ is selected from an alkylene group and a cycloalkylene group, and Carbon number is 1-18, m is 1-4) There; x, y and z satisfy the relationship x + y + 2z = 3,0 ≦ x ≦ 3,0 ≦ y ≦ 2,0 ≦ z ≦ 1; R 4 is an alkylene group, cycloalkylene group, cycloalkylalkylene group R ⁵ is selected from an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, and an aralkyl group, and is selected from an alkenylene group, an arylene group, and an aralkylene group; And carbon number is 1-18. A compound represented by the following general formula (3):
_{A m B 3 - m Si- (} CH 2) a -S b - (CH 2) a -SiA m B 3-m ··· (3)
Wherein (3), A is _{C n H 2n + 1 O (} n is an integer of 1 to 3) or a chlorine atom, B is an alkyl group having 1 to 3 carbon atoms, m is an integer of 1 to 3, a is an integer of 1 to 9, and b is an integer of 1 or more. However, when m is 1, B may be the same or different from each other, and when m is 2 or 3, A may be the same or different from each other. A compound represented by the following general formula (4):
_{A m B 3 - m Si- (} CH 2) c -Y ··· (4)
Wherein (4), A is _{C n H 2n + 1 O (} n is an integer of 1 to 3) or a chlorine atom, B is an alkyl group having 1 to 3 carbon atoms, Y is a mercapto group, a vinyl group, It is an amino group, a glycidoxy group or an epoxy group, m is an integer of 1 to 3, and c is an integer of 0 to 9. However, when m is 1, B may be the same or different from each other, and when m is 2 or 3, A may be the same or different from each other. And a compound represented by the following general formula (5):
_{A m B 3-m Si- (} CH 2) a -S b -Z ··· (5)
Wherein (5), A is _{C n H 2n + 1 O (} n is an integer of 1 to 3) or a chlorine atom, B is an alkyl group having 1 to 3 carbon atoms, Z is a benzothiazolyl group, N, N -A dimethylthiocarbamoyl group or a methacryloyl group, m is an integer of 1 to 3, a is an integer of 1 to 9, and b is an integer of 1 or more and may have a distribution. However, when m is 1, B may be the same or different from each other, and when m is 2 or 3, A may be the same or different from each other. It is preferably at least one selected from the group consisting of compounds represented by These silane coupling agents may be used alone or in a combination of two or more.

Regarding the compound represented by the above formula (2), in the formula (2), in R ² , R ⁵ , R ⁶ and R ⁷ , the alkyl group may be linear or branched. , Methyl group, ethyl group, propyl group, isopropyl group and the like. The alkenyl group may be linear or branched, and examples of the alkenyl group include a vinyl group, an allyl group, and a methanyl group. Furthermore, 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 , examples of the aralkyl group include a phenethyl group.

In the above formula (2), in R ⁴ and R ⁸ , the alkylene group may be linear or branched, and examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, and a propylene group. Examples of the cycloalkylene group include a cyclohexylene group. Furthermore, in R ⁴ , the alkenylene group may be linear or branched, and examples of the alkenylene group include a vinylene group and a propenylene group. 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.

In the above formula (2), in R ³ , as — [O (R ⁸ O) _m ] _0.5 — group, 1,2-ethanedioxy group, 1,3-propanedioxy group, 1,4-butanedioxy Group, 1,5-pentanedioxy group, 1,6-hexanedioxy group and the like.

  Examples of the compound represented by the above formula (3) include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (3-methyldimethoxysilylpropyl) tetrasulfide, bis (3-Triethoxysilylethyl) tetrasulfide, bis (3-triethoxysilylpropyl) disulfide, bis (3-trimethoxysilylpropyl) disulfide, bis (3-triethoxysilylpropyl) trisulfide and the like can be mentioned.

  Examples of the compound represented by the above formula (4) include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3 -Aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane and the like.

  Furthermore, as the compound represented by the above formula (5), 3-trimethoxysilylpropyl-N, N-dimethylcarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide, 3-trimethoxysilylpropyl And methacryloyl monosulfide.

  In the rubber composition of the present embodiment, the use of the compound as the silane coupling agent (D) provides a tire having excellent workability during rubber processing and good braking performance and wear resistance on wet road surfaces. be able to. In addition, it is preferable to use the compound represented by the said Formula (2) among the compounds represented by the said Formula (2), (3), (4) or (5).

  In the rubber composition of the present embodiment, the mass ratio of the blending amount of the silane coupling agent (D) to the blending amount of the silica (B) ([blending amount of (D) / blending amount of (B)]. Is preferably 0.05 to 0.15 (5/100 to 15/100). When the mass ratio of the blending amount is 0.05 or more, the effect of reducing rolling resistance can be obtained more sufficiently, and when it is 0.15 or less, the extrudability such as porous can be more sufficiently deteriorated. Can be suppressed.

[Other ingredients]
The rubber composition of the present invention may contain a filler other than silica. Such fillers are not particularly limited, and those usually used in the rubber industry such as carbon black, alumina, aluminum hydroxide, clay, calcium carbonate and the like can be used. Although it does not specifically limit as said carbon black, For example, carbon black of various grades, such as SAF, ISAF, HAF, FEF, GPF, can be used. The total amount of the filler (including silica (B)) is preferably in the range of 20 parts by mass to 200 parts by mass with respect to 100 parts by mass of the rubber component (A), and 20 parts by mass to 120 parts by mass. More preferably, it is the range.

  In the rubber composition of the present invention, various chemicals usually used in the rubber industry, for example, a vulcanizing agent, a vulcanization accelerator, a softening agent, an anti-aging agent, as long as the effects of the present invention are not impaired. A scorch inhibitor, zinc white, stearic acid and the like can be contained.

  Examples of the vulcanizing agent include sulfur, and the amount thereof used is preferably 0.1 parts by mass to 10.0 parts by mass with respect to 100 parts by mass of the rubber component (A). It is more preferable that it is 0 mass part-5.0 mass parts. If the amount is less than 0.1 parts by mass, the fracture strength, wear resistance, and low heat build-up of the vulcanized rubber may be reduced. If the amount exceeds 10.0 parts by mass, rubber elasticity may be lost.

  The vulcanization accelerator that can be used in the rubber composition of the present invention is not particularly limited. For example, M (2-mercaptobenzothiazole), DM (dibenzothiazolyl disulfide), CZ (N-cyclohexyl). -2- benzothiazolylsulfenamide) thiazole type, DPG (diphenylguanidine) type guanidine type or TOT (tetrakis (2-ethylhexyl) thiuram disulfide) type thiuram vulcanization accelerator, etc. The amount used is preferably 0.1 parts by mass to 5.0 parts by mass, and 0.2 parts by mass to 3.0 parts by mass with respect to 100 parts by mass of the rubber component (A). More preferably. In addition, these vulcanization accelerators may be used independently and may use 2 or more types.

  Moreover, a process oil can be mentioned as a softening agent which can be used in the rubber composition of this invention. Examples of the process oil include paraffinic, naphthenic, and aromatic oils. Aromatics are used for applications that emphasize tensile strength and wear resistance, and naphthenic or paraffinic systems are used for applications that emphasize hysteresis loss and low-temperature characteristics. The amount of use is preferably 0 to 100 parts by mass with respect to 100 parts by mass (A) of the rubber component. If the amount is 100 parts by mass or less, the vulcanized rubber has tensile strength and low heat build-up (low fuel consumption). Deterioration can be suppressed.

[Preparation of rubber composition]
The rubber component (A), silica (B), compound (C), silane coupling agent (D), and various compounding agents appropriately selected as necessary are generally known in the field of rubber compounding technology. Thus, for example, using standard rubber mixing equipment and techniques, the rubber composition can be prepared by mixing the above ingredients together in the desired amount used. The rubber composition of the present invention thus prepared has good processability and can improve the braking performance on wet road surfaces without impairing the rolling resistance of the tire.

[tire]
The tire of the present invention is characterized by comprising a component using the rubber composition, and the rubber composition is preferably used for a tire sidewall or tread, and particularly preferably used for a tread. Such tires are excellent in braking performance on wet road surfaces without impairing rolling resistance. The tire of the present invention is not particularly limited except that the above rubber composition is used for any constituent member of the tire, and can be produced according to a conventional method. When the rubber composition of the present invention is used for a tread, for example, it is extruded on a tread member, and is pasted and molded by a usual method on a tire molding machine to form a raw tire. The green tire is heated and pressed in a vulcanizer to obtain a tire.
As a gas filled in the tire, an inert gas such as nitrogen, argon, helium, or the like can be used in addition to normal or air having an adjusted oxygen partial pressure.

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

  In accordance with the formulation shown in Table 1, 19 types of rubber compositions of Examples 1 to 15 and Comparative Examples 1 to 4 were prepared under normal conditions. The rubber composition was evaluated for processability by the following method. The rubber composition was used as a tread and vulcanized under normal vulcanization conditions to produce a tire of size 195 / 65R15, and the rolling resistance and braking performance on wet road surfaces were evaluated by the following methods. These results are shown in Table 1.

<Processability of rubber composition>
In accordance with JIS K6300, Mooney viscosity (ML _{1 +} 4/130 ° C.) was measured at 130 ° C., the reciprocal of the measured value was obtained, and the value of Comparative Example 1 was displayed as an index. The larger the index value, the lower the unvulcanized viscosity and the better the workability.

<Brake performance on wet surfaces of tires>
Mount the above four prototype tires on a passenger car with a displacement of 2000 cc, run the passenger car on the wet evaluation road of the test course, step on the brake at 70 km / h to lock the tire, and set the distance to stop It was measured. The reciprocal of the measurement distance was determined, and the index was displayed with the value of Comparative Example 1 as 100. A larger index value indicates better braking performance on wet road surfaces.

<Tire rolling resistance>
For the above-mentioned prototype tire, a rolling drum having an outer diameter of 1707.6 mm with a steel smooth surface and a width of 350 mm was used, and rolling resistance was achieved by a coasting method when rotated at a speed of 80 km / h under the action of a load of 4500 N. Measurement was performed, the reciprocal of the measured value was obtained, and the value of Comparative Example 1 was set to 100 and indicated as an index. It shows that rolling resistance is so small that an index value is large.

1) E-SBR (Emulsion-polymerized styrene / butadiene rubber) 1712 (100 parts by mass of rubber component, 37.5 parts by mass of extended oil) manufactured by JSR Corporation
2) NIPSEAL AQ (Nitrogen adsorption specific surface area by BET method: 220 m ² / g) manufactured by Nippon Silica Kogyo Co., Ltd.
3) N134 (Nitrogen adsorption specific surface area: 146 m ² / g) manufactured by Asahi Carbon Co., Ltd.
4) manufactured by General Electric, NXT silane, chemical name: 3-octanoylthiopropyltriethoxysilane 5) manufactured by Degussa, Si69, chemical formula: (CH ₃ CH ₂ O) ₃ Si— (CH ₂ ) ₃ —S2 _{. 5 - (CH 2) 3 -Si} (OCH 2 CH 3) 3
6) Ionic surfactant A: manufactured by Kao Corporation, R ¹ = C ₂ H ₄ , R ² = CH ₃ , R ³ , R ⁴ and R ⁵ = H, n = 6, m = 15, A ¹ O = oxybutylene group, A ² O = oxyethylene group 7) Ionic surfactant B: manufactured by Kao Corporation, R ¹ = C ₂ H ₄ , R ² = CH ₃ , R ³ , R ⁴ and R ⁵ = Ethanol, n = 6, m = 15, A ¹ O = oxybutylene group, A ² O = oxyethylene group 8) Ionic surfactant C: manufactured by Kao Corporation, R ¹ = C ₂ H ₄ , R ² = CH ₃ , R ³ = stearyl group, R ⁴ and R ⁵ = CH ₃ , n = 6, m = 15, A ¹ O = oxybutylene group, A ² O = oxyethylene group 9) Ionic surfactant D: manufactured by Kao _{^{Corporation, R 1 = C 2 H 4}} , R 2 = CH 3, R 3, R 4 and ^{R 5 = H, n = 3} , = ^{15, A} 1 O = oxybutylene ^{group, A} 2 O = oxyethylene group 10) ionic surface active agent E: manufactured by Kao _{^{Corporation, R 1 = C 2 H 4}} , R 2 = CH 3, R 3, R ⁴ and R ⁵ = H, n = 3, m = 10, A ¹ O = oxybutylene group, A ² O = oxyethylene group 11) Ionic surfactant F: manufactured by Kao Corporation, R ¹ = C ₂ H ₄ , R ² = CH ₃ , R ³ , R ⁴ and R ⁵ are H, n = 7, m = 20, A ¹ O = oxybutylene group, A ² O = oxyethylene group 12) Ionic interface Activator G: manufactured by Kao Corporation, R ¹ = C ₂ H ₄ , R ² = CH ₃ , R ³ , R ⁴ and R ⁵ = H, n = 1, m = 10, A ¹ O = CH ₂ CH _(C 8 _{H 17)} O and _{CH 2 CH (C 10 H 21} ) a mixture of ^{O, a} 2 O = oxyethylene group 13) - isopropyl -N'- phenyl -p- phenylene diamine 14) Ouchi Shinko Chemical Industrial Co., Ltd., Nocceler DM
15) Sunseller CM-G, manufactured by Sanshin Chemical Industry Co., Ltd.

  From the results of Table 1, the compounding amount of silica (B) is 20 parts by mass to 120 parts by mass with respect to 100 parts by mass of the rubber component (A), and the compound (C) with respect to the compounding amount of the silica (B). The rubber composition having a mass ratio of the blending amount of 0.001 to 0.5 and further containing the silane coupling agent (D) has higher processability and rolling compared to the rubber composition of Comparative Example 1. It can be seen that resistance and braking performance on wet road surfaces are improved.

Claims (9)

At least one rubber component (A) selected from diene-based synthetic rubber and natural rubber;
Silica (B),
The following general formula (1):

[Wherein, R ¹ is an alkylene group having 1 to 4 carbon atoms or an arylene group which may have an alkyl group having 1 to 10 carbon atoms as a substituent, R ² is a hydrogen atom or a methyl group, R ³ , R ⁴ And R ⁵ represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms or an alkanol group having 2 to 4 carbon atoms, A ¹ is an alkylene group having 4 to 12 carbon atoms, and A ² is an alkylene group having 2 or 3 carbon atoms. Wherein n is an integer from 0 to 20 and m is an integer from 1 to 50], and at least one compound (C) selected from the group consisting of compounds represented by:
A tire rubber composition comprising a silane coupling agent (D),
The compounding amount of the silica (B) is 20 parts by mass to 120 parts by mass with respect to 100 parts by mass of the rubber component (A),
The mass ratio of the compounding amount of the compound (C) to the compounding amount of the silica (B) (expressed in [the compounding amount of (C) / (B) compounding amount)] is 0.001 to 0.5. The rubber composition for tires characterized by the above-mentioned.   The rubber composition for a tire according to claim 1, wherein the compounding amount of the compound (C) is 0.1 to 30 parts by mass with respect to 100 parts by mass of the rubber component (A).   The mass ratio of the compounding amount of the silane coupling agent (D) to the compounding amount of the silica (B) (represented by [the compounding amount of (D) / the compounding amount of (B)]) is 0.05 to 0.00. The tire rubber composition according to claim 1, which is 15. The silane coupling agent (D) has the following general formula (2):
_{^{R 1 x R 2 y R 3}} z Si-R 4 -S-CO-R 5 ··· (2)
[Wherein R ¹ represents 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 ) _n (OSiR ⁵ R ⁶ R ⁷ ) and having 1 to 18 carbon atoms (provided that R ⁶ and R ⁷ are each independently an alkyl group, a cycloalkyl group, an alkenyl group, a cyclo Selected from alkenyl groups and aryl groups, and having 1 to 18 carbon atoms and n being 0 to 10); R ² is hydrogen or an alkyl group, cycloalkyl group or alkenyl group having 1 to 18 carbon atoms; R ³ is — [O (R ⁸ O) m] _0.5 — (wherein R ⁸ is selected from an alkylene group and a cycloalkylene group, and has a carbon number of 1-18 and m is 1-4) x, y and z is, x + y + 2z = 3,0 ≦ x ≦ 3,0 ≦ y ≦ 2,0 satisfy the relationship ≦ z ≦ 1; ^{R 4} is an alkylene group, cycloalkylene group, cycloalkylalkylene group, alkenylene Selected from a group, an arylene group and an aralkylene group and having 1 to 18 carbon atoms; R ⁵ is selected from an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group and an aralkyl group; The number is 1-18. The rubber composition for tires of Claim 1 which is at least 1 sort (s) chosen from the group which consists of a compound represented by these.   The tire rubber composition according to claim 1, wherein, in the general formula (1), n is an integer of 0 to 20, and m is an integer of 1 to 30.   The tire rubber composition according to claim 5, wherein in the general formula (1), n is an integer of 0 to 10, and m is an integer of 1 to 20.   The tire rubber composition according to claim 1, wherein the rubber component (A) contains 50% by mass to 100% by mass of a styrene-butadiene copolymer rubber.   The tire provided with the structural member using the rubber composition for tires as described in any one of Claims 1-7.   The tire according to claim 8, wherein the constituent member is a tread.