JP2021169563A - Rubber composition for tires, and pneumatic tire - Google Patents

Abstract

To provide a rubber composition for tires excellent in overall performance of grip performance and wear resistance, and a pneumatic tire using the same.SOLUTION: The rubber composition for tires contains an aromatic vinyl-conjugated diene-nonconjugated olefin copolymer (A), a resin component (B) containing a cyclic structure as a constituent unit, an aromatic vinyl-nonconjugated olefin copolymer (C), and a filler (D). The content of the aromatic vinyl-conjugated diene-nonconjugated olefin copolymer is 20 mass% or more in 100 mass% of a rubber component. The content of the filler is 70 pts.mass or more based on 100 pts.mass of the rubber component.SELECTED DRAWING: None

Description

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

A rubber composition for a tire, which is required to have grip performance, needs to improve hysteresis loss in order to exhibit grip force, but at the same time, it is also required to secure wear resistance. As a method for improving the hysteresis loss, for example, a method in which magnesium acetate and imidazole are used in combination (for example, Patent Document 1), a method in which the amount of filler is increased, and the like are known, but in terms of both grip performance and abrasion resistance, there are known methods. Further improvement is desired.

Japanese Unexamined Patent Publication No. 2007-138101

The present invention has been made in view of the above situation, and an object of the present invention is to provide a rubber composition for a tire having excellent overall grip performance and wear resistance, and a pneumatic tire using the same.

The present invention comprises an aromatic vinyl-conjugated diene-non-conjugated olefin copolymer (A), a resin component (B) containing a cyclic structure as a constituent unit, and an aromatic vinyl-non-conjugated olefin copolymer (C). , And the filler (D), and the content of the aromatic vinyl-conjugated diene-non-conjugated olefin copolymer in 100% by mass of the rubber component is 20% by mass or more, and the filling with respect to 100 parts by mass of the rubber component. The present invention relates to a rubber composition for a tire having an agent content of 70 parts by mass or more.

The aromatic vinyl-conjugated diene-non-conjugated olefin copolymer has a molar ratio (A3 / A2) of a non-conjugated olefin unit (A3) and a conjugated diene unit (A2) of 1.6 or more and 17.4 or less. Is preferable.

The molar ratio (A3 / A2) is preferably less than 5.8.

The content of the aromatic vinyl-conjugated diene-non-conjugated olefin copolymer in 100% by mass of the rubber component is preferably 80% by mass or more.

The rubber composition for a tire preferably contains an isoprene-based rubber.

The rubber composition for tires preferably contains silica.

The mass ratio (B / C) of the resin component (B) containing a cyclic structure as a constituent unit and the aromatic vinyl-non-conjugated olefin copolymer (C) is preferably 3.5 to 15.0.

The present invention also relates to a pneumatic tire using the rubber composition.

The present invention comprises an aromatic vinyl-conjugated diene-non-conjugated olefin copolymer (A), a resin component (B) containing a cyclic structure as a constituent unit, and an aromatic vinyl-non-conjugated olefin copolymer (C). , And the filler (D), and the content of the aromatic vinyl-conjugated diene-non-conjugated olefin copolymer in 100% by mass of the rubber component is 20% by mass or more, and the filling with respect to 100 parts by mass of the rubber component. Since the rubber composition for tires has an agent content of 70 parts by mass or more, it is possible to provide a rubber composition for tires and a pneumatic tire having excellent overall grip performance and abrasion resistance.

The rubber composition for a tire of the present invention includes an aromatic vinyl-conjugated diene-non-conjugated olefin copolymer (A), a resin component (B) containing a cyclic structure as a constituent unit, and an aromatic vinyl-non-conjugated olefin. The polymer (C) and the filler (D) are contained in a predetermined composition. As a result, the overall performance of grip performance and wear resistance can be improved.

The mechanism by which such an action is obtained is not clear, but it is inferred as follows.
Aromatic vinyl-conjugated diene-non-conjugated olefin copolymer containing aromatic vinyl as a constituent unit, a resin component containing a cyclic structure as a constituent unit, and an aromatic vinyl-non-conjugated olefin copolymer containing aromatic vinyl as a constituent unit. By blending three different cyclic structure-containing compounds of the coalescence, each of the three components can be dispersed by maintaining the distance between each molecule while exerting the interaction due to the cyclic structure. Furthermore, by incorporating a large amount of filler into it, the interaction between the polymers (A) to (C) and the filler increases, heat generation more than before is exhibited, and grip performance is enhanced. It is considered that excellent wear resistance is also imparted. Therefore, it is presumed that the overall performance of grip performance and wear resistance is improved by using the components (A) to (D) in a predetermined composition.

(Rubber component)
The rubber composition contains an aromatic vinyl-conjugated diene-non-conjugated olefin copolymer (A) as a rubber component. The aromatic vinyl-conjugated diene-non-conjugated olefin copolymer is a multi-dimensional copolymer containing an aromatic vinyl unit, a conjugated diene unit, and a non-conjugated olefin unit. The multiple copolymer (copolymer (A)) is a multiple copolymer containing an aromatic vinyl unit, a conjugated diene unit, and a non-conjugated olefin unit.

In the multiple copolymer (copolymer (A)), the aromatic vinyl unit is a constituent unit derived from the aromatic vinyl compound, and the aromatic vinyl compound includes styrene, α-methylstyrene, and 1-vinyl. Examples thereof include naphthalene, 3-vinyltoluene, ethylvinylbenzene, divinylbenzene, 4-cyclohexylstyrene, 2,4,6-trimethylstyrene and the like. These may be used alone or in combination of two or more, but styrene and α-methylstyrene are preferable, and styrene is more preferable.

In the multiple copolymer (copolymer (A)), the conjugated diene unit is a structural unit derived from the conjugated diene compound, and examples of the conjugated diene compound include 1,3-butadiene, isoprene, and 1,3. -Pentadiene, 2,3-dimethylbutadiene, 2-phenyl-1,3-butadiene, 1,3-hexadiene and the like can be mentioned. These may be used alone or in combination of two or more, but 1,3-butadiene and isoprene are preferable, and 1,3-butadiene is more preferable.

In the multiple copolymer (copolymer (A)), the non-conjugated olefin unit is a structural unit derived from the non-conjugated olefin, and the non-conjugated olefin includes, for example, ethylene, propylene, 1-butene, 1-pentene. , 1-hexene, 1-heptene, 1-octene and the like. These may be used alone or in combination of two or more, but ethylene, propylene and 1-butene are preferable, and ethylene is more preferable.

The multiple copolymer (copolymer (A)) may be, for example, a method for copolymerizing an aromatic vinyl compound, a conjugated diene compound and a non-conjugated olefin, an aromatic vinyl compound and a conjugated diene compound, or an aromatic vinyl. It can be prepared by a method in which a compound, a conjugated diene compound and a non-conjugated olefin are copolymerized and then a part of the conjugated diene unit is converted into a non-conjugated olefin unit by hydrogenation. That is, the multiple copolymer (copolymer (A)) may be a copolymer of an aromatic vinyl compound, a conjugated diene compound and a non-conjugated olefin, or a copolymer of an aromatic vinyl compound and a conjugated diene compound. Alternatively, it may be a hydrogenated additive (hydrogenated copolymer) of a copolymer of an aromatic vinyl compound, a conjugated diene compound and a non-conjugated olefin. These may be used alone or in combination of two or more. Of these, hydrogenated copolymers of aromatic vinyl compounds and conjugated diene compounds are preferable, and hydrogenated styrene-butadiene copolymers (hydrogenated SBR) are more preferable.

In preparing the above-mentioned multiple copolymer (copolymer (A)), the polymerization method is not particularly limited, and random polymerization or block polymerization may be used, but random polymerization is preferable.

When the multiple copolymer (copolymer (A)) is a hydrogenated copolymer, the hydrogenation method and reaction conditions are not particularly limited, and hydrogenation may be performed by a known method and known conditions. .. Usually, it is carried out at 20 to 150 ° C. under hydrogen pressurization of 0.1 to 10 MPa in the presence of a hydrogenation catalyst. Other manufacturing methods and conditions are not particularly limited, and for example, the contents described in International Publication No. 2016/039005 can be applied.

When the multiplex copolymer (copolymer (A)) is a hydrogenated copolymer, the hydrogenation rate is preferably 30 mol% or more, with the entire conjugated diene unit before hydrogenation being 100 mol%. It is preferably 50 mol% or more, more preferably 60 mol% or more, and preferably 95 mol% or less, more preferably 90 mol% or less, still more preferably 85 mol% or less. Within the above range, the effect tends to be better obtained.
The hydrogenation rate can be calculated from the spectral reduction rate of the unsaturated bond portion of the spectrum obtained by measuring ^{1 1 H-NMR.}

The content of the aromatic vinyl unit in 100% by mass of the multiple copolymer (copolymer (A)) is preferably 5% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more. Yes, and it is preferably 45% by mass or less, more preferably 35% by mass or less, and further preferably 30% by mass or less. Within the above range, the effect tends to be better obtained.

In the multiple copolymer (copolymer (A)), the content of the conjugated diene unit is preferably 2.0 mol% or more, more preferably 5.5 mol% or more, with the entire constituent unit as 100 mol%. It is more preferably 8.5 mol% or more, preferably 35.0 mol% or less, more preferably 30.0 mol% or less, still more preferably 25.0 mol% or less. Within the above range, the effect tends to be better obtained.

In the multiple copolymer (copolymer (A)), the content of the non-conjugated olefin unit is preferably 50 mol% or more, more preferably 60 mol% or more, still more preferably 60 mol% or more, with the entire constituent unit as 100 mol%. Is 70 mol% or more, preferably 95 mol% or less, more preferably 90 mol% or less, still more preferably 85 mol% or less. Within the above range, the effect tends to be better obtained.

The multiple copolymer (copolymer (A)) has a molar ratio (A3 / A2: amount of non-conjugated olefin units in the multiple copolymer) between the non-conjugated olefin unit (A3) and the conjugated diene unit (A2). (Mole) / The amount of conjugated diene unit (mol) in the multiple copolymer is preferably 1.6 or more, more preferably 1.8 or more, still more preferably 2.1 or more. The upper limit of the molar ratio is preferably 17.4 or less, more preferably 10.0 or less, further preferably 7.5 or less, and particularly preferably less than 5.8. Within the above range, the effect tends to be better obtained.

The mechanism by which such an action is obtained is not clear, but it is inferred as follows.
Non-conjugated olefins by reducing A3 / A2 to 17.4 or less in the conjugated diene units and non-conjugated olefin units forming flexible units in the aromatic vinyl-conjugated diene-non-conjugated olefin copolymer (A). It is suppressed that the volume occupied by the molecular chain of the unit becomes too large, and it becomes easy to interact with the resin component (B) containing a cyclic structure as a constituent unit and the copolymer (C) of aromatic vinyl and non-conjugated olefin. There is a tendency, and when it is less than 5.8, it is presumed that such an action function is remarkably exhibited. On the other hand, it is presumed that by setting A3 / A2 to 1.6 or more, it is possible to suppress the distance between the molecules from becoming too close and to obtain good dispersibility with each other.

In the present specification, the ratio of the aromatic vinyl unit, the conjugated diene unit, and the non-conjugated olefin unit can be calculated from the result of ^{1 1 H-NMR measurement.}

The weight average molecular weight (Mw) of the multiple copolymer (copolymer (A)) is preferably 100,000 or more, more preferably 150,000 or more, still more preferably 200,000 or more, and particularly preferably 400,000 or more. Further, it is preferably 2 million or less, more preferably 1.5 million or less, still more preferably 1 million or less, and particularly preferably 600,000 or more. Within the above range, the effect tends to be better obtained.
The weight average molecular weight (Mw) is a gel permeation chromatograph (GPC) (GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKGEL SUPERMULTIPORE HZ-M manufactured by Tosoh Corporation). It can be obtained by standard polystyrene conversion based on the measured value according to. Further, in the case of a copolymer having a modifying group, since the modifying group and the silica gel of the column interact with each other and an accurate Mw cannot be obtained, the Mw is measured before performing the modification treatment.

In the rubber composition, the content of the multiple copolymer (copolymer (A)) in 100% by mass of the rubber component is preferably 20% by mass or more, more preferably 30% by mass or more, still more preferably 50. By mass or more, particularly preferably 80% by mass or more. The upper limit of the content is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 87% by mass or less. Within the above range, the effect tends to be better obtained. In particular, when 80% by mass or more is blended, it is presumed that the above-mentioned action and effect of the large amount of the copolymer (A) is greatly exhibited, and the overall performance of grip performance and wear resistance is remarkably improved.

In the rubber composition, examples of the rubber component that can be used in addition to the multiple copolymer include isoprene-based rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), and styrene-isoprene-butadiene. Examples thereof include diene rubber such as polymerized rubber (SIBR). These may be used alone or in combination of two or more. Of these, SBR, isoprene-based rubber, and BR are preferable, and SBR and isoprene-based rubber are more preferable.

The SBR is not particularly limited, and for example, emulsion polymerization SBR (E-SBR), solution polymerization SBR (S-SBR), and the like, which are common in the tire industry, can be used. These may be used alone or in combination of two or more.

When the rubber composition contains SBR, the content of SBR in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 13% by mass or more. The upper limit of the content is preferably 80% by mass or less, more preferably 70% by mass or less, and further preferably 50% by mass or less. Within the above range, the effect tends to be better obtained.

Examples of isoprene rubber include isoprene rubber (IR), epoxidized isoprene rubber, hydrogenated isoprene rubber, grafted isoprene rubber, natural rubber (NR), deproteinized natural rubber (DPNR), and high-purity natural rubber (UPNR). , Epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), grafted natural rubber and the like. These may be used alone or in combination of two or more. Of these, NR is preferable.

When the rubber composition contains isoprene-based rubber, the content of isoprene-based rubber in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 13% by mass or more. Is. The upper limit of the content is preferably 50% by mass or less, more preferably 30% by mass or less, and further preferably 20% by mass or less. Within the above range, the effect tends to be better obtained.

The rubber component may be either non-modified rubber or modified rubber.
The modified rubber may be any rubber having a functional group that interacts with a filler such as silica. For example, terminal modification in which at least one end of the rubber is modified with the compound having the functional group (modifying agent). Rubber (terminal modified rubber having the above functional group at the end), main chain modified rubber having the above functional group in the main chain, and main chain terminal modified rubber having the above functional group in the main chain and the end (for example, in the main chain) A main chain terminal modified rubber having the above functional group and at least one end modified with the above modifying agent) or a polyfunctional compound having two or more epoxy groups in the molecule (coupling) to form a hydroxyl group. And end-modified rubber into which an epoxy group has been introduced.

Examples of the functional group include an amino group, an amide group, a silyl group, an alkoxysilyl group, an isocyanate group, an imino group, an imidazole group, a urea group, an ether group, a carbonyl group, an oxycarbonyl group, a mercapto group, a sulfide group and a disulfide. Examples thereof include a group, a sulfonyl group, a sulfinyl group, a thiocarbonyl group, an ammonium group, an imide group, a hydrazo group, an azo group, a diazo group, a carboxyl group, a nitrile group, a pyridyl group, an alkoxy group, a hydroxyl group, an oxy group and an epoxy group. .. In addition, these functional groups may have a substituent. Among them, an amino group (preferably an amino group in which the hydrogen atom of the amino group is replaced with an alkyl group having 1 to 6 carbon atoms), an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms), and an alkoxysilyl group (preferably an alkoxy group having 1 to 6 carbon atoms). An alkoxysilyl group having 1 to 6 carbon atoms) is preferable.

Specific examples of the compound having the above functional group (modifier) include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, and 3-dimethylaminopropyltriethoxy. Examples thereof include silane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane.

(Resin component (B))
The rubber composition contains a resin component containing a cyclic structure as a constituent unit. The resin component (B) is a resin component (polymer) containing a cyclic structure as a constituent unit, and is a multiple element containing the copolymer (A) (aromatic vinyl unit, conjugated diene unit, and non-conjugated olefin unit). It is a resin component other than the copolymer) and the copolymer (C) described later (a copolymer containing an aromatic vinyl unit and a non-conjugated olefin unit). The resin component (B) is preferably a component that can be extracted with a solvent from the rubber composition (vulcanized rubber composition) using the resin component. Further, the resin component (B) is preferably a solid resin (a resin in a solid state at room temperature (25 ° C.)). Examples of the cyclic structure include aromatic rings, alicyclic rings, and heterocyclic rings and polycycles thereof. Among them, an aromatic ring is preferable, and a benzene ring is more preferable.

Examples of the resin component containing the cyclic structure as a constituent unit include aromatic vinyl polymers, kumaron inden resins, kumaron resins, inden resins, phenol resins, rosin resins, petroleum resins, terpene resins, and acrylic resins. Be done. Commercial products include Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Toso Co., Ltd., Rutgers Chemicals Co., Ltd., BASF Co., Ltd., Arizona Chemical Co., Ltd., Nikko Chemical Co., Ltd., Japan Co., Ltd. Products such as catalysts, JXTG Energy Co., Ltd., Arakawa Chemical Industry Co., Ltd., Taoka Chemical Industry Co., Ltd., and Toa Synthetic Co., Ltd. can be used. These may be used alone or in combination of two or more.

Examples of the aromatic vinyl polymer include α-methylstyrene and / or a resin obtained by polymerizing styrene. Specifically, a homopolymer of styrene (styrene resin) and a single weight of α-methylstyrene. Examples thereof include coalescence (α-methylstyrene resin), a polymer of α-methylstyrene and styrene, and a polymer of styrene and other monomers.

Examples of the marron indene resin include resins containing marron and indene as main monomer components constituting the skeleton (main chain) of the resin. Examples of the monomer component contained in the skeleton other than kumaron and indene include styrene, α-methylstyrene, methylindene, vinyltoluene and the like.

Examples of the kumaron resin include a resin containing kumaron as a main monomer component constituting the skeleton (main chain) of the resin.

Examples of the indene resin include a resin containing indene as a main monomer component constituting the skeleton (main chain) of the resin.

Examples of the phenol resin include alkylphenol resins and the like. As the alkylphenol-based resin, for example, an alkylphenol aldehyde condensed resin obtained by reacting an alkylphenol with an aldehyde such as formaldehyde, acetaldehyde, or furfural with an acid or an alkali catalyst; an alkylphenol is reacted with an alkyne such as acetylene. Obtained alkylphenol alkyne condensed resin; modified alkylphenol resin obtained by modifying these resins with compounds such as cashew oil, tall oil, flaxseed oil, various animal and vegetable oils, unsaturated fatty acids, rosin, alkylbenzene resin, aniline, and melamine; etc. Can be mentioned. Of these, an alkylphenol alkyne condensed resin is preferable, and an alkylphenol acetylene condensed resin is particularly preferable.

Examples of the alkylphenol constituting the alkylphenol resin include cresol, xylenol, t-butylphenol, octylphenol, nonylphenol and the like. Among them, phenol having a branched alkyl group such as t-butylphenol is preferable, and t-butylphenol is particularly preferable.

Examples of the rosin resin include natural rosin, polymerized rosin, modified rosin, ester compounds thereof, and rosin-based resins typified by these hydrogenated additives.

Examples of the petroleum resin include C5 resin, C9 resin, C5 / C9 resin, dicyclopentadiene (DCPD) resin and the like.

As the terpene-based resin, a polyterpene resin obtained by polymerizing a terpene compound, an aromatic-modified terpene resin obtained by polymerizing a terpene compound and an aromatic compound, and the like can be used. Moreover, these hydrogenated additives can also be used.

The polyterpene resin is a resin obtained by polymerizing a terpene compound. The terpene compound _is a hydrocarbon and oxygenated derivative _{(C 5} H ₈₎ represented by a composition of _n, monoterpenes _(C 10 _{H 16),} sesquiterpene _(C 15 _{H 24),} diterpenes _{(C 20} H It is a compound having a terpene as a basic skeleton classified into _{32) and the like.} Examples thereof include terpinene, 1,8-cineole, 1,4-cineol, α-terpineol, β-terpineol, and γ-terpineol.

Examples of the polyterpene resin include pinene resin, limonene resin, dipentene resin, and pinene / limonene resin made from the above-mentioned terpene compound. Of these, pinene resin is preferable because it is easy to carry out a polymerization reaction and is inexpensive because it is made from natural pine fat. The pinene resin usually contains both α-pinene and β-pinene having an isomer relationship, but depending on the difference in the contained components, β-pinene resin containing β-pinene as a main component and α- It is classified as α-pinene resin containing pinene as the main component.

Examples of the aromatic-modified terpene resin include terpene phenol resins made from the above terpene compounds and phenolic compounds, and terpene styrene resins made from the above terpene compounds and styrene compounds. Further, a terpene phenol styrene resin made from the above-mentioned terpene compound, phenol-based compound and styrene-based compound can also be used. Examples of the phenolic compound include phenol, bisphenol A, cresol, xylenol and the like. Examples of the styrene compound include styrene and α-methylstyrene.

As the acrylic resin, a styrene acrylic resin such as a styrene acrylic resin, which has a carboxyl group and is obtained by copolymerizing an aromatic vinyl monomer component and an acrylic monomer component, can be used. Among them, a solvent-free carboxyl group-containing styrene-acrylic resin can be preferably used.

Solventless carboxyl group-containing styrene acrylic resin is a high-temperature continuous polymerization method (high-temperature continuous lump polymerization method) (US Patent No. 1) without using polymerization initiators, chain transfer agents, organic solvents, etc. as auxiliary raw materials as much as possible. 4,414,370, JP-A-59-6207, JP-A-5-58805, JP-A 1-313522, US Pat. No. 5,010,166, Toa Synthetic Research Annual Report It is a (meth) acrylic resin (polymer) synthesized by the method described in TREND2000 No. 3, p42-45 and the like. In addition, in this specification, (meth) acrylic means methacryl and acrylic.

Examples of the acrylic monomer component constituting the acrylic resin include (meth) acrylic acid, (meth) acrylic acid ester (alkyl ester such as 2-ethylhexyl acrylate, aryl ester, aralkyl ester, etc.), (meth) acrylamide, and the like. Examples thereof include (meth) acrylic acid derivatives such as (meth) acrylamide derivatives. In addition, (meth) acrylic acid is a general term for acrylic acid and methacrylic acid.

Examples of the aromatic vinyl monomer component constituting the acrylic resin include aromatic vinyls such as styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene, and divinylnaphthalene.

Further, as the monomer component constituting the acrylic resin, other monomer components may be used together with (meth) acrylic acid, (meth) acrylic acid derivative, and aromatic vinyl.

The softening points of resin components containing a cyclic structure as a constituent unit (aromatic vinyl polymer, kumaron inden resin, kumaron resin, inden resin, phenol resin, rosin resin, petroleum resin, terpene resin, acrylic resin, etc.) are 60 to 200 ° C. is preferable. The upper limit is more preferably 160 ° C. or lower, further preferably 150 ° C. or lower, and the lower limit is more preferably 100 ° C. or higher, further preferably 130 ° C. or higher. By keeping it within the above range, the above effect can be obtained more preferably.
In the present specification, the softening point is the temperature at which the ball drops when the softening point defined in JIS K 6220-1: 2001 is measured by a ring-ball type softening point measuring device.

The content of the resin component (B) containing the cyclic structure as a constituent unit is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 12 parts by mass or more with respect to 100 parts by mass of the rubber component. .. The upper limit of the content is preferably 60 parts by mass or less, more preferably 40 parts by mass or less, and further preferably 20 parts by mass or less. By keeping it within the above range, the above effect can be obtained more preferably.

Examples of commercially available products of the resin component (B) having a cyclic structure include Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Toso Co., Ltd., Rutgers Chemicals Co., Ltd., BASF Co., Ltd., and Arizona Chemical Co., Ltd. , Nikko Chemical Co., Ltd., Nippon Catalyst Co., Ltd., JXTG Energy Co., Ltd., Arakawa Chemical Industry Co., Ltd., Taoka Chemical Industry Co., Ltd., etc. can be used.

(Aromatic vinyl-non-conjugated olefin copolymer (C))
The rubber composition contains an aromatic vinyl-non-conjugated olefin copolymer (C). The aromatic vinyl-non-conjugated olefin copolymer is a copolymer containing an aromatic vinyl unit and a non-conjugated olefin unit. The copolymer (C) is a copolymer containing an aromatic vinyl unit and a non-conjugated olefin unit, and the copolymer (A) (aromatic vinyl unit, a conjugated diene unit, and a non-conjugated olefin). It is a copolymer other than a multi-dimensional copolymer containing a unit. The copolymer (C) may contain units other than the aromatic vinyl unit and the non-conjugated olefin unit, but is preferably a copolymer composed of only the aromatic vinyl unit and the non-conjugated olefin unit. .. Further, the copolymer (C) is preferably a solid resin (a resin in a solid state at room temperature (25 ° C.)).

In the above-mentioned copolymer (C), the aromatic vinyl unit is the same structural unit as the above-mentioned multiple copolymer (copolymer (A)), and the same aromatic vinyl compound can be preferably used. .. The non-conjugated olefin unit is the same structural unit as the above-mentioned multiple copolymer (copolymer (A)), and the same non-conjugated olefin can be preferably used. The copolymer (C) can be produced, for example, by the same production method as the multiple copolymer (copolymer (A)).

Examples of the copolymer (C) include polymers (resins) containing aromatic hydrocarbons such as styrene and aliphatic hydrocarbons such as ethylene and propylene as constituent monomers, and commercially available products include Stratol. , Performance adaptive company, etc. can be used. These may be used alone or in combination of two or more.

The softening point of the copolymer (C) is preferably 30 to 120 ° C. The upper limit is more preferably 100 ° C. or lower, further preferably 80 ° C. or lower, and the lower limit is more preferably 50 ° C. or higher, further preferably 60 ° C. or higher. By keeping it within the above range, the above effect can be obtained more preferably.

The lower limit of the content of the non-conjugated olefin unit in 100% by mass of the copolymer (C) is preferably 50% by mass or more, more preferably 65% by mass or more, still more preferably 75% by mass, and the upper limit is. It is preferably 98% by mass or less, more preferably 95% by mass or less, and further preferably 90% by mass or less. By keeping it within the above range, the above effect can be obtained more preferably.

The content of the copolymer (C) is preferably 0.5 parts by mass or more, more preferably 1.0 part by mass or more, and further preferably 1.5 parts by mass or more with respect to 100 parts by mass of the rubber component. Yes, and it is preferably 12.0 parts by mass or less, more preferably 8.0 parts by mass or less, and further preferably 4.0 parts by mass or less. When it is within the above range, the above effect can be obtained more preferably. When the copolymer (C) is an ethylene propylene styrene copolymer described later, the same content is preferable.

Among the above copolymers (C), a resin containing ethylene, propylene and styrene as constituent monomers (ethylene propylene styrene copolymer) is preferable.

The lower limit of the softening point of the ethylene propylene styrene copolymer is preferably 20 ° C. or higher, more preferably 40 ° C. or higher, further preferably 60 ° C. or higher, and the upper limit is preferably 140 ° C. or lower, more preferably 100 ° C. or lower. More preferably, it is 85 ° C. or lower. By keeping it within the above range, the above effect can be obtained more preferably.

When the copolymer (C) is an ethylene propylene styrene copolymer, the lower limit of the ethylene propylene content (EP content) in 100% by mass of the ethylene propylene styrene copolymer is preferably 60% by mass or more. It is more preferably 70% by mass or more, further preferably 80% by mass or more, and the upper limit is preferably 98% by mass or less, more preferably 95% by mass or less, still more preferably 90% by mass or less. By keeping it within the above range, the above effect can be obtained more preferably.

In the above rubber composition, the mass ratio of the resin component (B) containing a cyclic structure as a constituent unit and the aromatic vinyl-non-conjugated olefin copolymer (C) (content of the resin component (B) (parts by mass) / The content (parts by mass) of the copolymer (C)) is preferably 3.5 or more, more preferably 5.5 or more, and even more preferably 6.5 or more. The upper limit of the compounding ratio is preferably 15.0 or less, more preferably 12.0 or less, and even more preferably 9.5 or less. Within the above range, the effect tends to be better obtained.

(Filler (D))
The rubber composition contains a filler.
The content of the filler is 70 parts by mass or more with respect to 100 parts by mass of the rubber component. By keeping it within the above range, the above effect can be preferably obtained. The lower limit of the content is preferably 75 parts by mass or more, more preferably 78 parts by mass or more. The upper limit is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, and further preferably 120 parts by mass or less.

The filler can be used without particular limitation as long as it is generally used in tires. Examples of the filler include silica, carbon black, aluminum hydroxide, clay, calcium carbonate, montmorillonite, cellulose, glass balloons, and various short fibers. These may be used alone or in combination of two or more. Of these, carbon black and silica are preferable.

The carbon black is not particularly limited, and examples thereof include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. As commercial products, products such as Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin Nikka Carbon Co., Ltd., Columbia Carbon Co., Ltd. are used. can. These may be used alone or in combination of two or more.

Nitrogen adsorption specific surface area _(N 2 SA) of carbon black is preferably ^{80 m} 2 / g or more, more preferably 100 m ² / g or more, more preferably 114m ² / g or more, and preferably 160 m ² / g Below, it is more preferably 140 m ² / g or less, ^{still more preferably 125 m 2} / g or less. Within the above range, the effect tends to be better obtained.
The carbon black N ₂ SA is a value measured in accordance with JIS K6217-2: 2001.

The content of carbon black is preferably 72 parts by mass or more, 75 parts by mass or more, and more preferably 78 parts by mass or more with respect to 100 parts by mass of the rubber component. The upper limit is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, and further preferably 120 parts by mass or less. Within the above range, the effect tends to be better obtained.

Examples of silica include dry silica (silicic anhydride) and wet silica (hydrous silicic acid), but wet silica is preferable because it contains a large amount of silanol groups. As commercially available products, products such as EVONIK, Tosoh Silica Co., Ltd., Solvay Japan Co., Ltd., and Tokuyama Corporation can be used. These may be used alone or in combination of two or more.

The average particle size of silica is preferably 75 nm or less, more preferably 50 nm or less, still more preferably 30 nm or less. The lower limit is not particularly limited, but is preferably 5 nm or more, more preferably 15 nm or more.
The average particle size of silica is a number average particle size, which is measured by a transmission electron microscope.

Nitrogen adsorption specific surface area _(N 2 SA) of silica is preferably 100 m ² / g or more, more preferably 150 meters ² / g or more, more preferably 170m ² / g or more, and preferably not more than 250 meters ² / g , More preferably 220 m ² / g or less, ^{still more preferably 200 m 2} / g or less. Within the above range, the effect tends to be better obtained.
The nitrogen adsorption specific surface area of silica is a value measured by the BET method according to ASTM D3037-81.

The content of silica is preferably 72 parts by mass or more, 75 parts by mass or more, and more preferably 78 parts by mass or more with respect to 100 parts by mass of the go rubber component. The upper limit is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, and further preferably 120 parts by mass or less. Within the above range, the effect tends to be better obtained.

Silica is preferably used in combination with a silane coupling agent.
The silane coupling agent is not particularly limited, and for example, bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (4-triethoxysilylbutyl) tetrasulfide, Bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (2-triethoxysilylethyl) trisulfide, bis (4-trimethoxysilylbutyl) trisulfide, bis ( 3-Triethoxysilylpropyl) disulfide, bis (2-triethoxysilylethyl) disulfide, bis (4-triethoxysilylbutyl) disulfide, bis (3-trimethoxysilylpropyl) disulfide, bis (2-trimethoxysilylethyl) ) Disulfide, bis (4-trimethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyltetrasulfide, 3- Sulfide type such as triethoxysilylpropyl methacrylate monosulfide, 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, mercapto type such as NXT and NXT-Z manufactured by Momentive, vinyl triethoxysilane, vinyl tri Vinyl type such as methoxysilane, amino type such as 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane, glycidoxy such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane. Examples thereof include nitro systems such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane, and chloro systems such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane. As commercially available products, products such as EVONIK, Momentive, Shinetsu Silicone Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azumax Co., Ltd., and Toray Dow Corning Co., Ltd. can be used. These may be used alone or in combination of two or more.

The content of the silane coupling agent is preferably 3 parts by mass or more, more preferably 6 parts by mass or more, and preferably 12 parts by mass or less, more preferably 9 parts by mass or less, based on 100 parts by mass of silica. Is. Within the above range, the effect tends to be better obtained.

(oil)
The rubber composition may contain oil.
Examples of the oil include process oils, vegetable oils and fats, or mixtures thereof. As the process oil, for example, a paraffin-based process oil, an aroma-based process oil, a naphthenic-based process oil, or the like can be used. Vegetable oils and fats include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, palm oil, peanut oil, rosin, pine oil, pineapple, tall oil, corn oil, rice oil, beni flower oil, sesame oil, Examples thereof include olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, and tung oil. Commercial products include Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., JXTG Energy Co., Ltd., Orisoi Co., Ltd., H & R Co., Ltd., Toyokuni Seiyu Co., Ltd., Showa Shell Sekiyu Co., Ltd., Fuji Kosan Co., Ltd., etc. Products can be used. These may be used alone or in combination of two or more.

The oil content is preferably 15 parts by mass or more, more preferably 25 parts by mass or more, still more preferably 30 parts by mass or more, and preferably 55 parts by mass or less, based on 100 parts by mass of the rubber component. It is preferably 50 parts by mass or less, more preferably 45 parts by mass or less. Within the above range, the effect tends to be better obtained. In the present specification, the oil content also includes the amount of oil contained in the oil spread rubber.

(Other ingredients)
The rubber composition may contain wax.
The wax is not particularly limited, and examples thereof include petroleum wax such as paraffin wax and microcrystalline wax; natural wax such as plant wax and animal wax; and synthetic wax such as a polymer such as ethylene and propylene. As commercially available products, products such as Ouchi Shinko Kagaku Kogyo Co., Ltd., Nippon Seiro Co., Ltd., and Seiko Kagaku Co., Ltd. can be used. These may be used alone or in combination of two or more.

The content of the wax is preferably 0.5 parts by mass or more, more preferably 0.7 parts by mass or more, and preferably 3.0 parts by mass or less, more preferably more preferably, with respect to 100 parts by mass of the rubber component. It is 2.5 parts by mass or less.

The rubber composition may contain an anti-aging agent.
Examples of the anti-aging agent include naphthylamine-based anti-aging agents such as phenyl-α-naphthylamine; diphenylamine-based anti-aging agents such as octylated diphenylamine and 4,4'-bis (α, α'-dimethylbenzyl) diphenylamine; N. -Isopropyl-N'-phenyl-p-phenylenediamine, N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, N, N'-di-2-naphthyl-p-phenylenediamine, etc. P-Phenylenediamine-based anti-aging agent; quinoline-based anti-aging agent such as a polymer of 2,2,4-trimethyl-1,2-dihydroquinolin; 2,6-di-t-butyl-4-methylphenol, Monophenolic anti-aging agents such as styrenated phenol; tetrakis- [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] bis, tris, polyphenolic aging such as methane Preventive agents and the like can be mentioned. As commercially available products, products of Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., Flexis Co., Ltd., etc. can be used. These may be used alone or in combination of two or more.

The content of the anti-aging agent is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 6 parts by mass or less, more preferably 4 parts by mass or less, based on 100 parts by mass of the rubber component. Is.

The rubber composition may contain stearic acid.
As the stearic acid, conventionally known ones can be used, and as commercially available products, products such as NOF Corporation, Kao Corporation, Fujifilm Wako Pure Chemical Industries, Ltd., and Chiba Fatty Acid Co., Ltd. can be used. These may be used alone or in combination of two or more.

The content of stearic acid is preferably 0.5 parts by mass or more, more preferably 1.0 part by mass or more, and preferably 5.0 parts by mass or less, more preferably, with respect to 100 parts by mass of the rubber component. Is 2.5 parts by mass or less.

The rubber composition may contain zinc oxide.
Conventionally known zinc oxide can be used, and commercially available products include Mitsui Metal Mining Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Shodo Chemical Industry Co., Ltd., and Sakai Chemical Industry Co., Ltd. And other products can be used. These may be used alone or in combination of two or more.

The content of zinc oxide is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 10 parts by mass or less, more preferably 6 parts by mass or less, based on 100 parts by mass of the rubber component. be.

The rubber composition may contain sulfur.
Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and soluble sulfur, which are generally used in the rubber industry. As commercially available products, products such as Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Chemicals Corporation, Flexis Co., Ltd., Nippon Inui Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. can be used. These may be used alone or in combination of two or more.

The sulfur content is preferably 0.5 parts by mass or more, more preferably 0.8 parts by mass or more, still more preferably 1.0 parts by mass or more, and preferably 1.0 part by mass or more, based on 100 parts by mass of the rubber component. It is 6.0 parts by mass or less, more preferably 3.0 parts by mass or less, still more preferably 2.0 parts by mass or less. Within the above range, the effect tends to be better obtained.

The rubber composition may contain a vulcanization accelerator.
Examples of the vulcanization accelerator include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole and di-2-benzothiazolyl disulfide; tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), and tetrakis (2). -Ethylhexyl) Thiuram-based vulcanization accelerators such as thiuram disulfide (TOT-N); N-cyclohexyl-2-benzothiazil sulfenamide (CBS), N-tert-butyl-2-benzothiazolyl sulfenamide ( TBBS), N-oxyethylene-2-benzothiazolesulfenamide, N, N'-diisopropyl-2-benzothiazolesulfenamide and other sulfenamide-based vulcanization accelerators; diphenylguanidine, dioltotrilguanidine, ortho Examples thereof include guanidine-based vulcanization accelerators such as trylbiguanidine. As commercially available products, products such as Sumitomo Chemical Co., Ltd. and Ouchi Shinko Chemical Industry Co., Ltd. can be used. These may be used alone or in combination of two or more.

The content of the vulture accelerator is preferably 1.0 part by mass or more, more preferably 2.5 parts by mass or more, still more preferably 3.0 parts by mass or more, and more preferably 3.0 parts by mass or more, based on 100 parts by mass of the rubber component. It is preferably 7.0 parts by mass or less, more preferably 5.0 parts by mass or less, and further preferably 4.0 parts by mass or less. Within the above range, the effect tends to be better obtained.

In addition to the above components, the rubber composition contains additives generally used in the tire industry, such as organic peroxides; fillers such as calcium carbonate, talc, alumina, clay, aluminum hydroxide, and mica. ; Etc. may be further blended. The content of these additives is preferably 0.1 to 200 parts by mass with respect to 100 parts by mass of the rubber component.

The rubber composition can be produced, for example, by kneading each of the above components using a rubber kneading device such as an open roll or a Banbury mixer, and then vulcanizing.

As the kneading conditions, in the base kneading step of kneading additives other than the vulcanizing agent and the vulcanization accelerator, the kneading temperature is usually 100 to 180 ° C., preferably 120 to 170 ° C. In the final kneading step of kneading the vulcanizing agent and the vulcanization accelerator, the kneading temperature is usually 120 ° C. or lower, preferably 85 to 110 ° C. Further, the composition obtained by kneading the vulcanizing agent and the vulcanization accelerator is usually subjected to a vulcanization treatment such as press vulcanization. The vulcanization temperature is usually 140 to 190 ° C, preferably 150 to 185 ° C. The vulcanization time is usually 5 to 15 minutes.

The above rubber compositions are used for tires such as sidewalls, base treads, bead apex, clinch apex, inner liner, under tread, breaker tread, bright topping, tread (single layer tread, multi-layer tread cap tread, etc.). It can be suitably used for members, and is particularly suitable for treads.

The tire is manufactured by a conventional method using the rubber composition.
That is, an unvulcanized tire is formed by extruding the rubber composition according to the shape of a tread or the like at the unvulcanized stage and molding the rubber composition together with other tire members by a normal method on a tire molding machine. To form. A tire is obtained by heating and pressurizing this unvulcanized tire in a vulcanizer.

The tread of the tire may be composed of at least a part of the rubber composition, and may be entirely composed of the rubber composition.

The above tires (pneumatic tires, etc.) are passenger car tires; truck / bus tires; two-wheeled vehicle tires; high-performance tires; winter tires such as studless tires; run-flat tires having side reinforcing layers; sound absorbing members such as sponges. A tire with a sound absorbing member provided in the tire cavity; a tire having a sealing member provided inside the tire or inside the tire cavity with a sealant that can be sealed at the time of puncture; It can be used for tires with electronic parts and the like, and is suitable for passenger car tires.

The present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

Hereinafter, various chemicals used in Examples and Comparative Examples will be described.
SBR: SLR6430 manufactured by TRINSEO (containing 37.5 parts by mass of oil with respect to 100 parts by mass of rubber solids)
NR: TSR20
Copolymer (A-1): Production Example A below (styrene unit 25% by mass, ethylene unit 58.9 mol%, butadiene unit 30.5 mol%, A3 / A2 = 1.9, hydrogenation rate 50 mol%) , Mw: 5000)
Copolymer (A-2): Production Example A below (styrene unit 25% by mass, ethylene unit 86.4 mol%, butadiene unit 5.0 mol%, A3 / A2 = 17.4, hydrogenation rate 90 mol%) , Mw: 300,000)
Copolymer (A-3): Production Example A below (styrene unit 25% by mass, ethylene unit 74.1 mol%, butadiene unit 16.4 mol%, A3 / A2 = 4.5, hydrogenation rate 70 mol%) , Mw: 250,000)
_{Carbon black: N220 (N 2} SA114m ² / g) manufactured by Cabot Japan Co., Ltd.
Silica: ULTRASIL VN3 manufactured by EVONIK (N ₂ SA175m ² / g, average particle size 17 nm)
Silane coupling agent: Si266 (bis (3-triethoxysilylpropyl) disulfide) manufactured by EVONIK
Resin component (B-1): BASF's cholesterol (pt-butylphenol acetylene resin (condensation resin of pt-butylphenol and acetylene), softening point 145 ° C., Tg98 ° C.)
Resin component (B-2): Esclon V120 manufactured by Nippon Steel Chemical Co., Ltd. (Kumaron inden resin, softening point 120 ° C)
Copolymer (C-1): Stractol 40MS manufactured by Stractol (ethylene propylene styrene copolymer, EP content 82% by mass)
Copolymer (C-2): Septon SEPS2004 (ethylene propylene styrene copolymer) manufactured by Kuraray Co., Ltd.
Wax: Ozo Ace 0355 manufactured by Nippon Seiro Co., Ltd.
Anti-aging agent 6C: Nocrack 6C (N-phenyl-N'-(1,3-dimethylbutyl) -p-phenylenediamine) (6PPD) manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Anti-aging agent RD: Nocrack RD (Poly (2,2,4-trimethyl-1,2-dihydroquinoline)) manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Oil: Diana Process NH-70S (aroma process oil) manufactured by Idemitsu Kosan Co., Ltd.
Stearic acid: Stearic acid "Camellia" manufactured by NOF CORPORATION
Zinc oxide: Zinc oxide No. 1 vulcanization accelerator manufactured by Mitsui Metal Mining Co., Ltd. NS: Noxeller NS (N-tert-butyl-2-benzothiazyl sulfenamide) manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Vulcanization accelerator ZTC: Noxeller ZTC (zinc dibenzyldithiocarbamate) manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Vulcanization accelerator CZ: Noxeller CZ (N-cyclohexyl-2-benzothiazolyl sulfeneamide) manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Vulcanization accelerator DPG: Noxeller D (N, N'-diphenylguanidine) manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Sulfur: HK-200-5 (5% by mass oil-containing powdered sulfur) manufactured by Hosoi Chemical Industry Co., Ltd.

<Production Example A: Production of aromatic vinyl-conjugated diene-non-conjugated olefin copolymers (A-1) to (A-3)>
Add n-hexane, styrene, 1,3-butadiene, TMEDA (N, N, N', N'-tetramethylethylenediamine), and n-butyllithium to a heat-resistant reaction vessel sufficiently substituted with nitrogen, and add 5 at 50 ° C. The mixture was stirred for a time and the polymerization reaction was carried out. Then, hydrogen gas was stirred for 20 minutes while being supplied at a pressure of 0.4 MPa-Gauge, and reacted with unreacted polymer-terminated lithium to obtain lithium hydride. The hydrogen gas supply pressure was 0.7 MPa-Gauge, the reaction temperature was 90 ° C., and hydrogenation was carried out using a catalyst mainly composed of titanocene dichloride. When the integrated amount of hydrogen absorption reaches the desired hydrogenation rate, the reaction temperature is set to room temperature, the hydrogen pressure is returned to normal pressure, the hydrogen pressure is removed from the reaction vessel, the reaction solution is stirred and poured into water, and the solvent is steamed. Aromatic vinyl-conjugated diene-non-conjugated olefin copolymers (A-1) to (A-3) were obtained by removing by stripping. In addition, (A-1) to (A-3) were prepared by adjusting the amount of styrene and 1,3-butadiene, the time of hydrogenation, and the like.

<Examples and Comparative Examples>
According to the formulation shown in each table, materials other than sulfur and vulcanization accelerator are kneaded for 5 minutes using a 1.7L vanbury mixer manufactured by Kobe Steel, Ltd., and discharged at 150 ° C. to discharge the kneaded product. Obtained. Next, sulfur and a vulcanization accelerator were added to the obtained kneaded product, and the mixture was kneaded for 5 minutes under the condition of 80 ° C. using an open roll to obtain an unvulcanized rubber composition.
The unvulcanized rubber composition was molded into the shape of a tread and bonded together with other tire members on a tire molding machine to form an unvulcanized tire, which was vulcanized at 170 ° C. for 10 minutes to obtain a test tire. ..

The following evaluation was performed using the above test tire. The results are shown in each table. The reference comparative examples in Tables 1, 2, 3, 4, 5, and 6 are Comparative Examples 1-1, 2-1 and 3-1, 4-1 and 5-1 and 6-1 respectively.

(Grip performance)
The above test tires were mounted on a domestic FR vehicle with a displacement of 2000 cc, and the actual vehicle ran 10 laps on a test course on a dry asphalt road surface, and a sensory test was conducted by a test driver on the grip performance on the dry road surface. A score was given on a scale of 10 by 10 test drivers, and based on the result, an index was displayed with a reference comparison example of 100 (grip performance index). The larger the value, the higher the grip performance (dry grip performance) on the dry road surface.

(Abrasion resistance)
The above test tires were mounted on a domestic FR vehicle with a displacement of 2000 cc, and the actual vehicle was run on a test course on a dry asphalt road surface. The amount of remaining grooves in the tire tread rubber after running by 10 test drivers was measured, the average was calculated, and the average amount of remaining grooves in the standard comparative example was set as 100 and displayed as an index (wear resistance index). The larger the value, the higher the wear resistance.

As an evaluation standard for the overall performance of grip performance and wear resistance, it was judged by the sum of each index of grip performance and wear resistance.

From each table, an aromatic vinyl-conjugated diene-non-conjugated olefin copolymer (A), a resin component (B) containing a cyclic structure as a constituent unit, and a copolymer of aromatic vinyl and a non-conjugated olefin (C). ) And the filler (D) in a predetermined composition were excellent in the overall performance of grip performance and wear resistance (the sum of the indexes of grip performance and wear resistance). Further, comparison of Comparative Examples 1-1, 1-2, 1-3, 1-4 and Example 1-1, Comparative Examples 2-1, 2-2, 2-3, 2-4 and Example 2- In comparison with 1, the combined use of the copolymer (A), the resin component (B), the copolymer (C) and the filler (D) synergistically improves the overall grip performance and wear resistance. rice field.

Claims (8)

An aromatic vinyl-conjugated diene-non-conjugated olefin copolymer (A), a resin component (B) containing a cyclic structure as a constituent unit, an aromatic vinyl-non-conjugated olefin copolymer (C), and a filler ( Including D)
The content of the aromatic vinyl-conjugated diene-non-conjugated olefin copolymer in 100% by mass of the rubber component is 20% by mass or more.
A rubber composition for a tire in which the content of the filler with respect to 100 parts by mass of the rubber component is 70 parts by mass or more. The aromatic vinyl-conjugated diene-non-conjugated olefin copolymer has a molar ratio (A3 / A2) of a non-conjugated olefin unit (A3) and a conjugated diene unit (A2) of 1.6 or more and 17.4 or less. The rubber composition for a tire according to claim 1. The rubber composition for a tire according to claim 2, wherein the molar ratio (A3 / A2) is less than 5.8. The rubber composition for a tire according to any one of claims 1 to 3, wherein the content of the aromatic vinyl-conjugated diene-non-conjugated olefin copolymer in 100% by mass of the rubber component is 80% by mass or more. The rubber composition for a tire according to any one of claims 1 to 4, which comprises isoprene-based rubber. The rubber composition for a tire according to any one of claims 1 to 5, which comprises silica. Claims 1 to 6 in which the mass ratio (B / C) of the resin component (B) containing a cyclic structure as a constituent unit and the aromatic vinyl-non-conjugated olefin copolymer (C) is 3.5 to 15.0. The rubber composition for a tire according to any one of. A pneumatic tire using the rubber composition according to any one of claims 1 to 7.