Tire composition and tire

Abstract

To provide a composition for a tire capable of improving chipping resistance during high speed travelling, and a tire using the same.SOLUTION: A composition for a tire contains at least one kind of a liquid plasticizer selected from a group consisting of an elastomer component, liquid rubber, a liquid resin and an ester-based plasticizer, and a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene-based resin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a tire composition and a tire. [Background technology]

[0002] Various methods have been studied to improve the chipping resistance of pneumatic tires. For example, Patent Document 1 discloses a method of compounding natural rubber, silica, and cyclized rubber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-012768 Summary of the Invention [Problem to be solved by the invention]

[0004] As a result of extensive research by the present inventors, it has become clear that there is room for improvement in chipping resistance during high-speed running in the conventional technology. The present invention aims to solve the new problem discovered by the present inventors and to provide a tire composition capable of improving chipping resistance during high-speed running, and a tire using the same. [Means for solving the problem]

[0005] The present invention comprises an elastomer component; at least one liquid plasticizer selected from the group consisting of liquid rubber, liquid resin, and ester-based plasticizer; The present invention relates to a tire composition comprising a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene resin.

[0006] The tire composition preferably has a ratio of (total blending amount of dicyclopentadiene-aromatic compound copolymer resin and hydrogenated dicyclopentadiene resin) / total blending amount of the liquid plasticizer of 0.1 to 10, more preferably 1.1 to 1.5.

[0007] The tire composition preferably contains silica, and more preferably the amount of silica blended is 5 to 200 parts by mass per 100 parts by mass of the elastomer component.

[0008] The tire composition preferably contains a mercapto-based silane coupling agent.

[0009] In the tire composition, the total amount of silica blended / the total amount of liquid plasticizer blended is preferably 1.0-30.

[0010] In the tire composition, the total amount of the dicyclopentadiene-aromatic compound copolymer resin and the hydrogenated dicyclopentadiene resin is preferably 80 parts by mass or less per 100 parts by mass of the elastomer component.

[0011] The tire composition is preferably for use in a tread.

[0012] The tire composition is preferably for use in passenger car tires.

[0013] The present invention also relates to a tire having tire components using the above composition.

[0014] The tire component is preferably a tread. [Effects of the Invention]

[0015] According to the present invention, the tire composition contains an elastomer component, at least one liquid plasticizer selected from the group consisting of liquid rubber, liquid resin, and ester-based plasticizer, and a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene-based resin, thereby improving chipping resistance during high-speed running. DETAILED DESCRIPTION OF THE INVENTION

[0016] The tire composition of the present invention includes an elastomer component, at least one liquid plasticizer selected from the group consisting of liquid rubber, liquid resin, and ester-based plasticizer, and a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene-based resin, thereby improving chipping resistance during high-speed running.

[0017] The tire composition described above provides the above-mentioned effects, and although the reason why such effects are obtained is not entirely clear, it is presumed as follows. The inventors' investigations have revealed that dicyclopentadiene-aromatic compound copolymer resins and / or hydrogenated dicyclopentadiene resins usually have low compatibility with elastomer components. In contrast, by using a dicyclopentadiene-aromatic compound copolymer resin and / or hydrogenated dicyclopentadiene resin in combination with at least one liquid plasticizer selected from the group consisting of liquid rubber, liquid resin, and ester-based plasticizers, the compatibility between the dicyclopentadiene-aromatic compound copolymer resin and / or hydrogenated dicyclopentadiene resin and the elastomer component is improved, resulting in a synergistic improvement in chipping resistance during high-speed running.

[0018] Chemicals that can be used in the tire composition will be described below.

[0019] The elastomer component is not particularly limited, and examples thereof include thermoplastic elastomers, rubber components, etc. These may be used alone or in combination of two or more. Among these, rubber components are preferred. In this specification, the elastomer component refers to a polymer component that is a base component of the composition and has elasticity.

[0020] The weight average molecular weight (Mw) of the elastomer component is preferably 50,000 or more, more preferably 150,000 or more, and even more preferably 350,000 or more. There is no particular upper limit to Mw, but it is preferably 4,000,000 or less, more preferably 3,000,000 or less.

[0021] The thermoplastic elastomer is not particularly limited, and examples thereof include olefin-based thermoplastic elastomers, styrene-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, urethane-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and fluorine-based thermoplastic elastomers. These may be used alone or in combination of two or more. Among these, styrene-based thermoplastic elastomers are preferred.

[0022] The styrene-based thermoplastic elastomer is not particularly limited as long as it is a thermoplastic elastomer having a styrene unit (preferably a styrene block unit), but examples thereof include styrene-isobutylene-styrene block copolymer (SIBS), styrene-isoprene-styrene block copolymer (SIS), styrene-isobutylene block copolymer (SIB), styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), and styrene-butadiene-butylene-styrene block copolymer (SBBS). These may be used alone or in combination of two or more. Among these, SIS, SBS, SEBS, and SBBS are preferred, with SIS and SEBS being more preferred.

[0023] As the thermoplastic elastomer, for example, thermoplastic elastomers manufactured and sold by Kaneka Corporation, Kraton Polymers, Asahi Kasei Corporation, etc. can be used.

[0024] The rubber component is not particularly limited, and examples thereof include diene rubbers such as isoprene rubber, butadiene rubber (BR), styrene butadiene rubber (SBR), styrene isoprene butadiene rubber (SIBR), acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), and butyl rubber (IIR); acrylic rubbers such as butyl acrylate rubber, ethyl acrylate rubber, and octyl acrylate rubber; nitrile rubber; isobutylene rubber; silicone rubber (millable type, room temperature vulcanization type); and fluororubber. The rubber component may be used alone or in combination of two or more. Among these, diene rubbers are preferred, with isoprene rubber, BR, and SBR being more preferred, and BR and SBR being even more preferred.

[0025] The content of the rubber component in 100% by mass of the elastomer component is preferably 20% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, particularly preferably 80% by mass or more, and most preferably 90% by mass or more, and may even be 100% by mass. When it is within the above range, better effects tend to be obtained.

[0026] The content of the diene rubber in 100% by mass of the elastomer component is preferably 20% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, particularly preferably 80% by mass or more, and most preferably 90% by mass or more, and may even be 100% by mass. When it is within the above range, better effects tend to be obtained.

[0027] The SBR is not particularly limited, and can be, for example, emulsion-polymerized SBR (E-SBR), solution-polymerized SBR (S-SBR), or other commonly used SBRs in the tire industry. These may be used alone or in combination of two or more.

[0028] The styrene content of the SBR is preferably 3% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, particularly preferably 15% by mass or more, and most preferably 20% by mass or more, and is preferably 60% by mass or less, more preferably 55% by mass or less, even more preferably 50% by mass or less, particularly preferably 45% by mass or less, most preferably 40% by mass or less, even most preferably 30% by mass or less, and even most preferably 25% by mass or less. Within the above ranges, the effects tend to be more favorably obtained.

[0029] The SBR may be unmodified or modified. The modified SBR may be any SBR having a functional group that interacts with a filler such as silica, and examples thereof include terminal-modified SBR in which at least one terminal of the SBR has been modified with a compound (modifier) ​​having the above functional group (terminal-modified SBR having the above functional group at the terminal), main-chain-modified SBR in which the main chain has the above functional group, main-chain-terminal-modified SBR in which the main chain and terminals have the above functional group (for example, main-chain-terminal-modified SBR in which the main chain has the above functional group and at least one terminal has been modified with the above modifier), and terminal-modified SBR modified (coupled) with a polyfunctional compound having two or more epoxy groups in the molecule and into which hydroxyl groups or epoxy groups have been introduced. These may be used alone or in combination of two or more.

[0030] Examples of the functional group include an amino group, an amido 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, a disulfide group, a sulfonyl group, a sulfinyl group, a thiocarbonyl group, an ammonium group, an imido 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. These functional groups may have a substituent. Among these, an amino group (preferably an amino group in which a hydrogen atom of an amino group is substituted with an alkyl group having 1 to 6 carbon atoms), an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms), an alkoxysilyl group (preferably an alkoxysilyl group having 1 to 6 carbon atoms), and an amide group are preferred.

[0031] As the SBR, for example, SBR manufactured and sold by Sumitomo Chemical Co., Ltd., JSR Corporation, Asahi Kasei Corporation, Nippon Zeon Co., Ltd., etc. can be used.

[0032] The content of SBR in 100% by mass of the elastomer component is preferably 20% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more, and although there is no particular upper limit, it is preferably 95% by mass or less, more preferably 90% by mass or less. Within the above range, better effects tend to be obtained.

[0033] The BR is not particularly limited, and can be one commonly used in the tire industry, such as a BR with a high cis content (high-cis BR), a BR containing 1,2-syndiotactic polybutadiene crystals (SPB), or a BR synthesized using a rare earth catalyst (rare earth BR). These can be used alone or in combination of two or more. Of these, high-cis BR is preferred because it provides the most suitable effect.

[0034] The cis content of BR is preferably 90% by mass or more, more preferably 95% by mass or more. There is no particular upper limit and it may be 100% by mass, but it is preferably 98% by mass or less. Within the above range, the effect tends to be more suitably obtained.

[0035] The BR may be either unmodified or modified. Modified BR includes modified BR having the aforementioned functional groups introduced therein. Preferred embodiments are the same as those for modified SBR.

[0036] As the BR, for example, products from Ube Industries, Ltd., JSR Corporation, Asahi Kasei Corporation, Nippon Zeon Corporation, etc. can be used.

[0037] The content of BR in 100% by mass of the elastomer component is not particularly limited to a lower limit, but is preferably 5% by mass or more, more preferably 10% by mass or more, and is preferably 80% by mass or less, more preferably 50% by mass or less, and even more preferably 30% by mass or less. Within the above ranges, the effects tend to be more favorably obtained.

[0038] Examples of isoprene-based rubbers include natural rubber (NR), isoprene rubber (IR), modified NR, modified NR, and modified IR. NRs such as SIR20, RSS#3, and TSR20 are commonly used in the tire industry. IRs are not particularly limited, and examples of IRs such as IR2200 are commonly used in the tire industry. Modified NRs include deproteinized natural rubber (DPNR) and highly purified natural rubber (UPNR). Modified NRs include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber. Modified IRs include epoxidized isoprene rubber, hydrogenated isoprene rubber, and grafted isoprene rubber. These may be used alone or in combination of two or more. NR is preferred.

[0039] The content of the isoprene-based rubber in 100% by mass of the elastomer component is preferably 5% by mass or more, more preferably 10% by mass or more, and is preferably 40% by mass or less, more preferably 30% by mass or less.

[0040] In this specification, the weight average molecular weight (Mw) and number average molecular weight (Mn) can be determined in terms of standard polystyrene based on measurements obtained using a gel permeation chromatograph (GPC) (GPC-8000 series, manufactured by Tosoh Corporation; detector: differential refractometer; column: TSKGEL SUPERMULTIPORE HZ-M, manufactured by Tosoh Corporation). The cis content (cis-1,4-bonded butadiene unit content) and vinyl content (1,2-bonded butadiene unit content) can be measured by infrared absorption spectroscopy, and the styrene content can be measured by 1 It can be measured by H-NMR measurement.

[0041] The composition (preferably an elastomer composition, more preferably a rubber composition) contains a dicyclopentadiene-aromatic compound copolymer resin (DCPD-aromatic compound copolymer resin) and / or a hydrogenated dicyclopentadiene resin (hydrogenated DCPD resin). These may be used alone or in combination of two or more. Of these, dicyclopentadiene-aromatic compound copolymer resin is preferred.

[0042] In this specification, the dicyclopentadiene-aromatic compound copolymer resin refers to a resin obtained by copolymerizing dicyclopentadiene with an aromatic compound. The dicyclopentadiene-aromatic compound copolymer resin may be hydrogenated.

[0043] The ratio of the aromatic compound to dicyclopentadiene can be set as appropriate, but the aromaticity is preferably 2% by mass or more, more preferably 5% by mass or more, and even more preferably 8% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 12% by mass or less. Within the above range, the effect tends to be better obtained. In this specification, the aromaticity means the content of aromatic compound-derived units in 100% by mass of the dicyclopentadiene-aromatic compound copolymer resin.

[0044] The weight average molecular weight (Mw) of the dicyclopentadiene-aromatic compound copolymer resin is preferably 200 or more, more preferably 300 or more, and even more preferably 500 or more, and is preferably 5000 or less, more preferably 3000 or less, even more preferably 2000 or less, particularly preferably 1500 or less, and most preferably 1000 or less. Within the above ranges, better effects tend to be obtained.

[0045] The aromatic compound is not particularly limited as long as it is a compound having an aromatic ring, and examples thereof include phenolic compounds such as phenol, alkylphenol, alkoxyphenol, and unsaturated hydrocarbon group-containing phenol; naphthol compounds such as naphthol, alkylnaphthol, alkoxynaphthol, and unsaturated hydrocarbon group-containing naphthol; styrene derivatives such as styrene, alkylstyrene, alkoxystyrene, and unsaturated hydrocarbon group-containing styrene; coumarone, indene, etc. These may be used alone or in combination of two or more. Among these, phenol and styrene derivatives are preferred, styrene derivatives are more preferred, alkylstyrenes are even more preferred, and α-methylstyrene is particularly preferred. The number of carbon atoms in the alkyl group or alkoxy group in the above compound is preferably 1 to 20, more preferably 1 to 12, even more preferably 1 to 8, particularly preferably 1 to 5, and most preferably 1 to 3. The number of carbon atoms in the unsaturated hydrocarbon group in the above compound is preferably 2 to 20, more preferably 2 to 12, and even more preferably 2 to 5. The aromatic compound may have one or more substituents on the aromatic ring, and when there are two or more substituents on the aromatic ring, the substitution position may be any of the o-position, m-position, and p-position. Furthermore, in a styrene derivative having a substituent on the aromatic ring, the substitution position of the substituent may be the o-position, m-position, or p-position relative to the vinyl group derived from styrene. These aromatic compounds may be used alone or in combination of two or more.

[0046] Specific examples of the alkylphenol include methylphenol, ethylphenol, butylphenol, t-butylphenol, octylphenol, nonylphenol, decylphenol, and dinonylphenol. These may be substituted at the o-, m-, or p-position. Among these, t-butylphenol is preferred, and pt-butylphenol is more preferred.

[0047] Specific examples of the alkylnaphthol include compounds in which the phenol moiety of the alkylphenol is replaced with naphthol.

[0048] Specific examples of the alkylstyrene include compounds in which the phenol moiety of the alkylphenol is replaced with styrene.

[0049] Specific examples of the alkoxyphenols include compounds in which the alkyl groups of the alkylphenols are replaced with corresponding alkoxy groups.Similarly, specific examples of the alkoxynaphthols include compounds in which the alkyl groups of the alkylnaphthols are replaced with corresponding alkoxy groups.Furthermore, specific examples of the alkoxystyrenes include compounds in which the alkyl groups of the alkylstyrenes are replaced with corresponding alkoxy groups.

[0050] The unsaturated hydrocarbon group-containing phenol includes a compound containing at least one hydroxyphenyl group in one molecule, and in which at least one hydrogen atom of the phenyl group is substituted with an unsaturated hydrocarbon group. The unsaturated bond in the unsaturated hydrocarbon group may be a double bond or a triple bond. The unsaturated hydrocarbon group includes an alkenyl group having 2 to 10 carbon atoms.

[0051] Specific examples of the unsaturated hydrocarbon group-containing phenol include isopropenylphenol, butenylphenol, etc. The same applies to the unsaturated hydrocarbon group-containing naphthol and the unsaturated hydrocarbon group-containing styrene.

[0052] In this specification, the hydrogenated dicyclopentadiene resin means a hydrogenated dicyclopentadiene resin. In this specification, a dicyclopentadiene-based resin refers to a resin (excluding dicyclopentadiene-aromatic compound copolymer resins) containing dicyclopentadiene as the main monomer component constituting the resin skeleton (main chain), and the content of dicyclopentadiene-derived units in 100% by mass of the resin is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, particularly preferably 98% by mass or more, and most preferably 100% by mass. By keeping the content within the above range, the above-mentioned effects tend to be more suitably obtained. Examples of dicyclopentadiene-based resins include petroleum resins produced using dicyclopentadiene, which is obtained by dimerizing cyclopentadiene extracted from the C5 fraction of petroleum, as the main raw material.

[0053] The hydrogenation can be carried out by known methods, and for example, catalytic hydrogenation using a metal catalyst, a method using hydrazine, and the like can all be suitably used (see, for example, JP-A-59-161415). For example, catalytic hydrogenation using a metal catalyst can be carried out by adding hydrogen under pressure in an organic solvent in the presence of a metal catalyst, and tetrahydrofuran, methanol, ethanol, and the like can all be suitably used as the organic solvent. These organic solvents can be used alone or in combination of two or more. Furthermore, as the metal catalyst, for example, palladium, platinum, rhodium, ruthenium, nickel, and the like can all be suitably used. These metal catalysts can be used alone or in combination of two or more. The pressure when pressurizing can be, for example, 1 to 300 kgf / cm. 2 It is preferable that:

[0054] In the hydrogenated dicyclopentadiene resin, the hydrogenation rate of double bonds (hydrogenation rate) is preferably 20 mol% or more, more preferably 35 mol% or more, even more preferably 50 mol% or more, particularly preferably 65 mol% or more, most preferably 80 mol% or more, even most preferably 90 mol% or more, and even most preferably 100 mol%. By keeping it within the above range, the above effects tend to be more suitably obtained. In this specification, the hydrogenation rate (hydrogenation rate) is defined as follows: 1 It can be calculated from the spectral reduction rate of the double bond portion in the spectrum obtained by measuring H-NMR. In this specification, the hydrogenation rate (hydrogenation rate) means the hydrogenation rate of the double bond.

[0055] The softening point of the dicyclopentadiene-aromatic compound copolymer resin and the hydrogenated dicyclopentadiene resin is preferably 60 to 200° C. The upper limit is more preferably 160° C. or lower, and even more preferably 150° C. or lower, and the lower limit is more preferably 80° C. or higher, and even more preferably 90° C. or higher. By keeping the softening point within the above range, the above effects tend to be more suitably obtained. In this specification, the softening point of a resin is the temperature at which the ball drops when the softening point specified in JIS K 6220-1:2001 is measured using a ring and ball softening point tester.

[0056] As dicyclopentadiene-aromatic compound copolymer resins and hydrogenated dicyclopentadiene resins, for example, products available from JXTG Energy Corporation, Maruzen Petrochemical Co., Ltd., Exxon Mobil, etc. can be used.

[0057] In this specification, the content of each structural unit in the resin is 1 It is calculated by H-NMR measurement.

[0058] The content of the dicyclopentadiene-aromatic compound copolymer resin and the hydrogenated dicyclopentadiene resin (the total content of the dicyclopentadiene-aromatic compound copolymer resin and the hydrogenated dicyclopentadiene resin) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, per 100 parts by mass of the elastomer component (preferably the rubber component), and is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, even more preferably 40 parts by mass or less, and particularly preferably 30 parts by mass or less. Within the above ranges, better effects tend to be obtained.

[0059] The composition may contain a resin other than the dicyclopentadiene-aromatic compound copolymer resin and the hydrogenated dicyclopentadiene resin. Resins other than dicyclopentadiene-aromatic compound copolymer resins and hydrogenated dicyclopentadiene resins are not particularly limited, but examples include solid styrene resins, alkylphenol resins, coumarone-indene resins, terpene resins, rosin resins, acrylic resins, non-hydrogenated dicyclopentadiene resins, etc. These may be used alone or in combination of two or more.

[0060] Examples of resins that can be used other than dicyclopentadiene-aromatic compound copolymer resins and hydrogenated dicyclopentadiene resins include products from Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Arizona Chemical Company, Nitto Chemical Co., Ltd., Nippon Shokubai Co., Ltd., JXTG Nippon Oil & Energy Corporation, Arakawa Chemical Industries, Ltd., and Taoka Chemical Co., Ltd.

[0061] The composition contains at least one liquid plasticizer selected from the group consisting of liquid rubber, liquid resin, and ester-based plasticizer. These may be used alone or in combination of two or more. Among these, liquid rubber is preferred. Here, the liquid plasticizer refers to a plasticizer that is in a liquid state at room temperature (25°C).

[0062] The composition preferably contains an elastomer component, liquid rubber, and a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene resin; more preferably contains an elastomer component, liquid BR and / or liquid SBR, and a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene resin; and even more preferably contains an elastomer component, liquid SBR, and a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene resin. The composition preferably contains an elastomer component, a liquid resin, and a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene resin; more preferably contains an elastomer component, a liquid coumarone-indene resin and / or a liquid acrylic resin, and a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene resin; and still more preferably contains an elastomer component, a liquid coumarone-indene resin, a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene resin. The composition preferably contains an elastomer component, an ester-based plasticizer, and a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene-based resin; more preferably contains an elastomer component, a sebacic acid ester and / or an adipic acid ester, and a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene-based resin; and still more preferably contains an elastomer component, a sebacic acid ester, and a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene-based resin. In each of the preferred embodiments of the composition, it is preferable to use BR and / or SBR as the elastomer component, and it is more preferable to use BR and SBR. In each of the preferred embodiments of the composition, it is preferred that the SBR content in 100% by mass of the elastomer component is 50% by mass or more and 90% by mass or less, and the BR content in 100% by mass of the elastomer component is 10% by mass or more and 50% by mass or less. In each of the preferred embodiments of the composition, the content of the dicyclopentadiene-aromatic compound copolymer resin and the hydrogenated dicyclopentadiene resin (the total content of the dicyclopentadiene-aromatic compound copolymer resin and the hydrogenated dicyclopentadiene resin) is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, even more preferably 40 parts by mass or less, and particularly preferably 30 parts by mass or less, per 100 parts by mass of the elastomer component (preferably the rubber component). In each of the preferred embodiments, the composition preferably contains a dicyclopentadiene-aromatic compound copolymer resin.

[0063] Liquid rubber is a rubber component that is in a liquid state at room temperature (25°C). Examples of the rubber component include the rubber components described above, which may be used alone or in combination of two or more. Among them, diene rubbers are preferred, isoprene rubbers, BR, and SBR are more preferred, and BR and SBR are even more preferred. Farnesene polymers are also preferred.

[0064] The weight average molecular weight (Mw) of the liquid rubber is preferably 3.0×10 3 More preferably, 4.0 × 10 3 or more, preferably 1.0 × 10 5 Less than or equal to 1.5 × 10 4 Within the above range, the effect can be more suitably obtained.

[0065] As described above, the liquid rubber is preferably a liquid diene rubber (liquid diene polymer) or a liquid farnesene polymer. Examples of liquid diene polymers include liquid styrene-butadiene copolymer (liquid SBR), liquid butadiene polymer (liquid BR), liquid isoprene polymer (liquid IR), and liquid styrene-isoprene copolymer (liquid SIR). These may be used alone or in combination of two or more. Of these, liquid BR and liquid SBR are preferred, with liquid SBR being more preferred, as they provide the desired effect.

[0066] The styrene content of the liquid SBR is preferably 10% by mass or more, more preferably 20% by mass or more, and is preferably 55% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, and particularly preferably 30% by mass or less. Within the above ranges, the effects can be more suitably obtained.

[0067] The liquid farnesene polymer is a polymer obtained by polymerizing farnesene as a monomer component, and examples thereof include the polymers described in JP-A-2016-180118. The liquid farnesene polymer may be a homopolymer of farnesene (farnesene homopolymer) or a copolymer of farnesene and a vinyl monomer (farnesene-vinyl monomer copolymer). These may be used alone or in combination of two or more. Suitable vinyl monomers include styrene and butadiene.

[0068] As the liquid rubber, for example, products of Cray Valley, Kuraray Co., Ltd., etc. can be used.

[0069] Liquid resin is a resin that is in a liquid state at room temperature (25°C). The resin is not particularly limited, but examples thereof include styrene-based resins, alkylphenol-based resins, coumarone-indene resins, terpene-based resins, rosin-based resins, acrylic resins, non-hydrogenated dicyclopentadiene-based resins, dicyclopentadiene-aromatic compound copolymer resins, and hydrogenated dicyclopentadiene-based resins that are liquid at room temperature (25°C). These may be used alone or in combination of two or more. Among these, liquid coumarone-indene resins and liquid acrylic resins are preferred, and liquid coumarone-indene resins are more preferred.

[0070] Liquid coumarone-indene resin is a resin containing coumarone and indene as the main monomer components constituting the resin skeleton (main chain), and examples of monomer components that may be contained in the skeleton other than coumarone and indene include styrene, α-methylstyrene, methylindene, vinyltoluene, etc. These may be used alone or in combination of two or more. The total content of coumarone-derived units and indene-derived units in 100% by mass of the resin is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, particularly preferably 98% by mass or more, and most preferably 100% by mass. By keeping it within the above range, the above effects tend to be more suitably obtained.

[0071] A liquid acrylic resin is a resin containing (meth)acrylic as the main monomer component constituting the skeleton (main chain) of the resin, and examples of monomer components that may be contained in the skeleton other than (meth)acrylic include styrene, α-methylstyrene, methylindene, vinyltoluene, etc. These may be used alone or in combination of two or more. The total content of (meth)acrylic-derived units in 100% by mass of the resin is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, particularly preferably 98% by mass or more, and most preferably 100% by mass. By keeping it within the above range, the above-mentioned effects tend to be more suitably obtained.

[0072] The softening point of the liquid resin is preferably −20° C. or higher, more preferably −5° C. or higher, even more preferably 0° C. or higher, and is preferably 20° C. or lower, more preferably 18° C. or lower, even more preferably 17° C. or lower. By keeping the softening point within the above range, the above-mentioned effects tend to be more suitably obtained.

[0073] Examples of liquid resins that can be used include products from Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Tosoh Corporation, Rutgers Chemicals, BASF, Arizona Chemical Company, Nitto Chemical Co., Ltd., Nippon Shokubai Co., Ltd., JXTG Nippon Oil & Energy Corporation, Arakawa Chemical Industries, Ltd., and Taoka Chemical Co., Ltd.

[0074] The ester plasticizer is not particularly limited as long as it is a compound having an ester group that is liquid at room temperature (25°C), and examples thereof include phthalic acid derivatives, long-chain fatty acid derivatives, phosphoric acid derivatives, sebacic acid derivatives, and adipic acid derivatives. These may be used alone or in combination of two or more. Among these, sebacic acid derivatives and adipic acid derivatives are preferred. The phthalic acid derivatives are not particularly limited, but examples thereof include phthalate esters such as di-2-ethylhexyl phthalate (DOP) and diisodecyl phthalate (DIDP). The long-chain fatty acid derivatives are not particularly limited, but examples thereof include long-chain fatty acid glycerin esters. The phosphoric acid derivatives are not particularly limited, but examples thereof include phosphoric acid esters such as tri(2-ethylhexyl)phosphate (TOP) and tributyl phosphate (TBP). The sebacic acid derivatives are not particularly limited, but examples thereof include sebacic acid esters such as di(2-ethylhexyl)sebacate (DOS) and diisooctylsebacate (DIOS). The adipic acid derivatives are not particularly limited, but examples thereof include adipic acid esters such as di(2-ethylhexyl)adipate (DOA) and diisooctyladipate (DIOA). Of these, sebacic acid esters and adipic acid esters are preferred, DOS and DOA are more preferred, and DOS is even more preferred.

[0075] The glass transition temperature (Tg) of the ester-based plasticizer is preferably −110° C. or higher, more preferably −100° C. or higher, even more preferably −80° C. or higher, and is preferably −20° C. or lower, more preferably −40° C. or lower, even more preferably −55° C. or lower. By keeping the Tg within the above range, the above-mentioned effects tend to be more suitably obtained. In this specification, the glass transition temperature is a value measured in accordance with JIS-K7121 using a differential scanning calorimeter (Q200) manufactured by TA Instruments Japan at a heating rate of 10°C / min.

[0076] As the ester-based plasticizer, for example, products manufactured by Daihachi Chemical Industry Co., Ltd., Taoka Chemical Industry Co., Ltd., etc. can be used.

[0077] The content of the liquid plasticizer (total content of liquid rubber, liquid resin, and ester-based plasticizer) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and is preferably 70 parts by mass or less, more preferably 50 parts by mass or less, even more preferably 30 parts by mass or less, and particularly preferably 20 parts by mass or less, per 100 parts by mass of the elastomer component (preferably the rubber component). Within the above ranges, better effects tend to be obtained.

[0078] The composition may contain a plasticizer other than the liquid plasticizer. Plasticizers other than the liquid plasticizers include oils. Examples of oils include process oils, vegetable oils, and mixtures thereof. Examples of process oils that can be used include paraffin-based process oils, aromatic process oils, and naphthenic process oils. Examples of vegetable oils include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, rosin, pine oil, pine tar, tall oil, corn oil, rice bran oil, safflower oil, sesame oil, olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, and tung oil. These may be used alone or in combination of two or more.

[0079] As the oil, for example, products from Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., Japan Energy Co., Ltd., Orisoi Co., Ltd., H&R Co., Ltd., Toyokuni Oil Mills Co., Ltd., Showa Shell Sekiyu KK, Fuji Kosan Co., Ltd., etc. can be used.

[0080] The composition preferably contains silica. Blending a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene resin tends to increase the viscosity of the composition, which enhances the shear force acting on the silica during kneading, improving the dispersibility of the silica and more suitably improving chipping resistance during high-speed driving.

[0081] Examples of silica include dry-process silica (silicic anhydride) and wet-process silica (hydrated silicic acid), but wet-process silica is preferred because it contains a large number of silanol groups. These may be used alone or in combination of two or more.

[0082] The nitrogen adsorption specific surface area (N2SA) of the silica is preferably 50 m 2 / g or more, more preferably 80m 2 / g or more, more preferably 120m 2 / g or more, particularly preferably 150m 2 / g or more. In addition, the N2SA is preferably 600m 2 / g or less, more preferably 300m 2 / g or less, more preferably 250m 2 / g or less, particularly preferably 200m 2 Within the above range, the effect tends to be more favorably obtained. In this specification, the N2SA of silica is a value measured by the BET method in accordance with ASTM D3037-81.

[0083] As silica, for example, products from Degussa, Rhodia, Tosoh Silica Co., Ltd., Solvay Japan Co., Ltd., Tokuyama Corporation, etc. can be used.

[0084] The content of silica is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 40 parts by mass or more, particularly preferably 60 parts by mass or more, most preferably 70 parts by mass or more, and most preferably 80 parts by mass or more, per 100 parts by mass of the elastomer component (preferably the rubber component), and is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, even more preferably 120 parts by mass or less, and particularly preferably 100 parts by mass or less. Within the above ranges, the effects tend to be more suitably obtained.

[0085] In the composition, the content of silica in 100% by mass of the filler (reinforcing filler) is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, particularly preferably 90% by mass or more, and may be 100% by mass. When it is within the above range, the effect tends to be more suitably obtained.

[0086] When the composition contains silica, it is preferable that it further contains a silane coupling agent. The silane coupling agent is not particularly limited, and examples thereof include 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 Examples of such compounds include sulfide-based compounds such as N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, and 3-triethoxysilylpropyl methacrylate monosulfide; mercapto-based compounds such as 3-mercaptopropyltrimethoxysilane and 2-mercaptoethyltriethoxysilane; vinyl-based compounds such as vinyltriethoxysilane and vinyltrimethoxysilane; amino-based compounds such as 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane; glycidoxy-based compounds such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; nitro-based compounds such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; and chloro-based compounds such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane. Commercially available products that can be used include, for example, products from Degussa, Momentive, Shin-Etsu Silicones Co., Ltd., Tokyo Chemical Industry Co., Ltd., AZMAX Corporation, and Dow Corning Toray Co., Ltd. These may be used alone or in combination of two or more. Of these, sulfide-based silane coupling agents and mercapto-based silane coupling agents are preferred, with mercapto-based silane coupling agents being more preferred, as they tend to produce better effects.

[0087] As the mercapto-based silane coupling agent, in addition to a compound having a mercapto group, a compound having a structure in which the mercapto group is protected by a protecting group (for example, a compound represented by the following formula (III)) can also be used.

[0088] Particularly suitable mercapto-based silane coupling agents include silane coupling agents containing a bonding unit A represented by the following formula (I) and a bonding unit B represented by the following formula (II), and silane coupling agents represented by the following formula (III). Among these, silane coupling agents containing a bonding unit A represented by the following formula (I) and a bonding unit B represented by the following formula (II) are preferred.

[0089] Hereinafter, a silane coupling agent containing a bonding unit A represented by the following formula (I) and a bonding unit B represented by the following formula (II) will be described. [ka] [ka] (In the formula, x is an integer of 0 or more, and y is an integer of 1 or more. R 1 R represents hydrogen, halogen, a branched or unbranched alkyl group having 1 to 30 carbon atoms, a branched or unbranched alkenyl group having 2 to 30 carbon atoms, a branched or unbranched alkynyl group having 2 to 30 carbon atoms, or an alkyl group in which the terminal hydrogen atom has been substituted with a hydroxyl group or a carboxyl group. 2 represents a branched or unbranched alkylene group having 1 to 30 carbon atoms, a branched or unbranched alkenylene group having 2 to 30 carbon atoms, or a branched or unbranched alkynylene group having 2 to 30 carbon atoms. 1 and R 2 may form a ring structure with

[0090] In the silane coupling agent containing the bond unit A represented by formula (I) and the bond unit B represented by formula (II), the content of the bond unit A is preferably 30 mol% or more, more preferably 50 mol% or more, and preferably 99 mol% or less, more preferably 90 mol% or less. The content of the bond unit B is preferably 1 mol% or more, more preferably 5 mol% or more, even more preferably 10 mol% or more, and preferably 70 mol% or less, more preferably 65 mol% or less, even more preferably 55 mol% or less. The total content of the bond units A and B is preferably 95 mol% or more, more preferably 98 mol% or more, particularly preferably 100 mol%. The content of the bonding units A and B includes the case where the bonding units A and B are located at the terminals of the silane coupling agent. When the bonding units A and B are located at the terminals of the silane coupling agent, the form of the bonding units A and B is not particularly limited, as long as they form units corresponding to the formulas (I) and (II) representing the bonding units A and B.

[0091] R in formulas (I) and (II) 1 With respect to the above, examples of halogen include chlorine, bromine, and fluorine. Examples of branched or unbranched alkyl groups having 1 to 30 carbon atoms include methyl and ethyl groups. Examples of branched or unbranched alkenyl groups having 2 to 30 carbon atoms include vinyl and 1-propenyl groups. Examples of branched or unbranched alkynyl groups having 2 to 30 carbon atoms include ethynyl and propynyl groups.

[0092] R in formulas (I) and (II) 2 Regarding the above, examples of branched or unbranched alkylene groups having 1 to 30 carbon atoms include an ethylene group, a propylene group, etc. Examples of branched or unbranched alkenylene groups having 2 to 30 carbon atoms include a vinylene group, a 1-propenylene group, etc. Examples of branched or unbranched alkynylene groups having 2 to 30 carbon atoms include an ethynylene group, a propynylene group, etc.

[0093] In a silane coupling agent containing a bonding unit A represented by formula (I) and a bonding unit B represented by formula (II), the total number of repetitions (x+y) of the bonding unit A (x) and the bonding unit B (y) is preferably in the range of 3 to 300.

[0094] Examples of silane coupling agents containing the bonding unit A represented by the above formula (I) and the bonding unit B represented by the above formula (II) include NXT-Z15, NXT-Z30, NXT-Z45, and NXT-Z80 manufactured by Momentive Corp. These may be used alone or in combination of two or more.

[0095] The silane coupling agent represented by the following formula (III) will be explained below. (C p H 2p+1 O)3Si-C q H 2q -S-CO-C k H 2k+1 (III) (In the formula, p is an integer of 1 to 3, q ​​is an integer of 1 to 5, and k is an integer of 5 to 12.)

[0096] p is an integer of 1 to 3, preferably 2. When it is within the above range, the effect tends to be more favorably obtained.

[0097] q is an integer of 1 to 5, preferably 2 to 4, and more preferably 3. Within the above range, the effect tends to be more favorably obtained.

[0098] k is an integer of 5 to 12, preferably 5 to 10, more preferably 6 to 8, and even more preferably 7. When k is within the above range, the effect tends to be more favorably obtained.

[0099] An example of the silane coupling agent represented by the formula (III) is NXT manufactured by Momentive Corp. The silane coupling agents represented by the formula (III) may be used alone or in combination of two or more.

[0100] The content of the silane coupling agent is preferably 0.5 parts by mass or more, more preferably 3 parts by mass or more, and even more preferably 5 parts by mass or more, relative to 100 parts by mass of silica, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less. Within the above range, the effect tends to be more favorable.

[0101] The composition may also contain carbon black, which tends to provide better results. The carbon black is not particularly limited, and examples thereof include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. These may be used alone or in combination of two or more.

[0102] The nitrogen adsorption specific surface area (N2SA) of the carbon black is preferably 30 m 2 / g or more, more preferably 80m 2 / g or more, more preferably 100m 2 / g or more, and preferably 200m 2 / g or less, more preferably 150m 2 Within the above range, there is a tendency for the effect to be better obtained. In this specification, the N2SA of carbon black is a value measured in accordance with JIS K6217-2:2001.

[0103] As carbon black, for example, products of Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin-Nichika Carbon Co., Ltd., Columbia Carbon Company, etc. can be used.

[0104] The content of carbon black is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less, per 100 parts by mass of the elastomer component (preferably the rubber component). When the content is within the above range, better effects tend to be obtained.

[0105] The composition preferably contains sulfur as a crosslinking agent (vulcanizing agent). Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, soluble sulfur, etc., which are commonly used in the rubber industry. These may be used alone or in combination of two or more.

[0106] As sulfur, for example, products from Tsurumi Chemical Industry Co., Ltd., Karuizawa Iso Co., Ltd., Shikoku Chemical Industry Co., Ltd., Flexis Corporation, Nippon Kanritsu Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. can be used.

[0107] The sulfur content is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less, per 100 parts by mass of the elastomer component (preferably the rubber component). Within the above ranges, better effects tend to be obtained.

[0108] The composition preferably contains a vulcanization accelerator. Examples of the vulcanization accelerator include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole and di-2-benzothiazolyl disulfide; thiuram-based vulcanization accelerators such as tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), and tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N); sulfenamide-based vulcanization accelerators such as N-cyclohexyl-2-benzothiazolylsulfenamide, Nt-butyl-2-benzothiazolylsulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, and N,N'-diisopropyl-2-benzothiazolesulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, di-orthotolylguanidine, and orthotolylbiguanidine. These may be used alone or in combination of two or more. Of these, sulfenamide vulcanization accelerators and guanidine vulcanization accelerators are preferred, and a combined use of a sulfenamide vulcanization accelerator and a guanidine vulcanization accelerator is more preferred.

[0109] As the vulcanization accelerator, for example, products manufactured by Kawaguchi Chemical Co., Ltd., Ouchi Shinko Chemical Co., Ltd., Rhein Chemie AG, etc. can be used.

[0110] The content of the vulcanization accelerator is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, relative to 100 parts by mass of the elastomer component (preferably the rubber component). When the content is within the above range, better effects tend to be obtained.

[0111] The composition may include a wax. The wax is not particularly limited, and examples thereof include petroleum waxes such as paraffin wax and microcrystalline wax; natural waxes such as vegetable wax and animal wax; and synthetic waxes such as polymers of ethylene, propylene, etc. These may be used alone or in combination of two or more. Of these, petroleum waxes are preferred, and paraffin wax is more preferred.

[0112] As the wax, for example, products from Ouchi Shinko Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., Seiko Chemical Co., Ltd., etc. can be used.

[0113] The wax content is preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, and preferably 20 parts by mass or less, more preferably 10 parts by mass or less, per 100 parts by mass of the elastomer component (preferably the rubber component). Within the above ranges, better effects tend to be obtained.

[0114] The composition may also include an anti-aging agent. Examples of the antioxidant include naphthylamine-based antioxidants such as phenyl-α-naphthylamine; diphenylamine-based antioxidants 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, and N,N'-di-2-naphthyl-p-phenylenediamine. Examples of antioxidants include p-phenylenediamine antioxidants such as quinoline; quinoline antioxidants such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; monophenol antioxidants such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; and bis-, tris-, and polyphenol antioxidants such as tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. These antioxidants may be used alone or in combination of two or more. Among these, p-phenylenediamine antioxidants and quinoline antioxidants are preferred.

[0115] As the antioxidant, for example, products available from Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., Flexis, etc. can be used.

[0116] The content of the antioxidant is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, per 100 parts by mass of the elastomer component (preferably the rubber component). Within the above ranges, the effect tends to be better.

[0117] The composition may contain stearic acid. As the stearic acid, conventionally known ones can be used, for example, products available from NOF Corporation, Kao Corporation, Fujifilm Wako Pure Chemical Industries, Ltd., Chiba Fatty Acid Co., Ltd., etc.

[0118] The content of stearic acid is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, per 100 parts by mass of the elastomer component (preferably the rubber component). When the content is within the above range, better effects tend to be obtained.

[0119] The composition may contain zinc oxide. As the zinc oxide, conventionally known products can be used, for example, products from Mitsui Mining & Smelting Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Seido Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc. can be used.

[0120] The content of zinc oxide is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, per 100 parts by mass of the elastomer component (preferably the rubber component). When the content is within the above range, better effects tend to be obtained.

[0121] In addition to the above components, the composition may further contain additives commonly used in the tire industry, such as organic peroxides, fillers such as aluminum hydroxide, calcium carbonate, talc, alumina, clay, mica, etc. The content of these additives is preferably 0.1 to 200 parts by mass per 100 parts by mass of the elastomer component (preferably the rubber component).

[0122] The composition can be produced, for example, by kneading the components using a rubber kneading device such as an open roll or a Banbury mixer, followed by vulcanization.

[0123] As for kneading conditions, in the base kneading step in which additives other than the vulcanizing agent and vulcanization accelerator are kneaded, the kneading temperature is usually 100 to 180°C, preferably 120 to 170°C. In the finish kneading step in which the vulcanizing agent and vulcanization accelerator are kneaded, the kneading temperature is usually 120°C or lower, preferably 80 to 110°C. Furthermore, the composition kneaded with the vulcanizing agent and vulcanization accelerator is usually subjected to a vulcanization treatment such as press vulcanization. The vulcanization temperature is usually 130 to 190°C, preferably 150 to 185°C. The vulcanization time is usually 5 to 30 minutes.

[0124] The composition can be used (as a rubber composition for tires) for tire components such as treads (cap treads), sidewalls, base treads, undertreads, clinches, bead apexes, breaker cushion rubbers, carcass cord covering rubbers, insulation, chafers, inner liners, and side reinforcing layers of run-flat tires. It is particularly suitable for use in treads (cap treads). In the case of a tread that is composed of a cap tread and a base tread, the composition can be used preferably in the cap tread.

[0125] In the composition, the ratio (total amount of dicyclopentadiene-aromatic compound copolymer resin and hydrogenated dicyclopentadiene resin) / total amount of the liquid plasticizer is preferably 0.1 to 10. The lower limit is more preferably 0.3 or more, even more preferably 0.5 or more, particularly preferably 0.67 or more, most preferably 0.9 or more, more preferably 1.1 or more, and even most preferably 1.2 or more. The upper limit is more preferably 9.0 or less, even more preferably 7.0 or less, particularly preferably 5.0 or less, most preferably 3.0 or less, more most preferably 2.0 or less, and even most preferably 1.5 or less. Within the above ranges, better effects tend to be obtained. Here, the blending amount means the blending amount per 100 parts by mass of the elastomer component (preferably the rubber component). The total amount of liquid plasticizers means the total amount of liquid rubber, liquid resin, and ester-based plasticizers. The above parameters can be achieved by appropriately adjusting the blending amount of the resin and the blending amount of the liquid plasticizer.

[0126] In the above composition, the ratio of the total amount of silica to the total amount of liquid plasticizer is preferably 1.0 to 30. The lower limit is more preferably 2.0 or more, even more preferably 3.0 or more, particularly preferably 4.0 or more, most preferably 5.0 or more, and most preferably 5.5 or more. The upper limit is more preferably 25 or less, even more preferably 20 or less, particularly preferably 15 or less, most preferably 10 or less, even most preferably 8.0 or less, even most preferably 7.0 or less, and particularly most preferably 6.5 or less. Within the above ranges, better effects tend to be obtained. Here, the blending amount means the blending amount per 100 parts by mass of the elastomer component (preferably the rubber component). The total amount of liquid plasticizers means the total amount of liquid rubber, liquid resin, and ester-based plasticizers. The above parameters can be achieved by appropriately adjusting the blending amount of silica and the blending amount of the liquid plasticizer.

[0127] The tire of the present invention is manufactured by a conventional method using the above composition. That is, the composition, to which various additives are optionally added, is extruded in an unvulcanized state to match the shapes of the tire components (particularly the tread (cap tread)), molded in a conventional manner on a tire building machine, and laminated together with other tire components to form an unvulcanized tire, which is then heated and pressurized in a vulcanizer to manufacture the tire.

[0128] The tread of the tire may be at least partially made of the composition, or may be entirely made of the composition.

[0129] The tire is not particularly limited, and examples thereof include pneumatic tires, solid tires, airless tires, etc. Among these, pneumatic tires are preferred.

[0130] The above tires are suitable for use as passenger car tires, large passenger car tires, large SUV tires, truck and bus tires, motorcycle tires, racing tires, winter tires (studless tires, snow tires, studded tires), all-season tires, run-flat tires, aircraft tires, mining tires, etc. The above tires are particularly suitable for use as passenger car tires. Here, passenger cars refer to automobiles used exclusively for human transportation. They are the most common type of automobile. [Example]

[0131] The present invention will be specifically described based on examples, but the present invention is not limited to these examples.

[0132] The various chemicals used in the examples and comparative examples will be collectively described below. SBR: NS616 (styrene content: 21% by mass) manufactured by Zeon Corporation BR: BR150B (cis content: 97% by mass) manufactured by Ube Industries, Ltd. Thermoplastic elastomer 1: D1161 (SIS) manufactured by Kraton Polymers Thermoplastic elastomer 2: Tuftec P2000 (SEBS) manufactured by Asahi Kasei Corporation Carbon black: N220 (N2SA:114m) manufactured by Mitsubishi Chemical 2 / g) Silica: Degussa VN3 (N2SA: 175 ml 2 / g) Silane coupling agent 1: NXT-Z45 (a copolymer of bonding unit A and bonding unit B (bonding unit A: 55 mol %, bonding unit B: 45 mol %)) manufactured by Momentive Silane coupling agent 2: NXT manufactured by Momentive (a silane coupling agent represented by the above formula (III), in which p=2, q=3, and k=7) Oil: Idemitsu Kosan Co., Ltd. Diana Process NH-70S (aromatic process oil) Liquid rubber 1: Ricon 134 (liquid BR, weight average molecular weight: 8000) manufactured by Cray Valley Liquid rubber 2: Ricon 100 manufactured by Cray Valley (liquid SBR, styrene content: 25% by mass, weight average molecular weight: 4500) Liquid resin 1: NOVARES C10 (liquid coumarone-indene resin, softening point: 5-15°C) manufactured by Rutgers Chemicals Liquid resin 2: UC3510 (liquid acrylic resin, Tg: -50°C) manufactured by Toagosei Co., Ltd. Ester-based plasticizer 1: Di(2-ethylhexyl) sebacate (Tg: -65°C) manufactured by Daihachi Chemical Industry Co., Ltd. Ester-based plasticizer 2: Di(2-ethylhexyl) adipate (Tg: -70°C) manufactured by Daihachi Chemical Industry Co., Ltd. Resin 1 (dicyclopentadiene-aromatic compound copolymer resin): Oppa PR-383 manufactured by Exxon Mobil (aromaticity: 9.6% by mass, softening point: 103°C, Mw: 770) Resin 2 (hydrogenated dicyclopentadiene resin): T-REZ OP501 (hydrogenated DCPD resin, softening point: 140°C, content of dicyclopentadiene-derived units: 100% by mass) manufactured by JXTG Energy Corporation Resin 3 (non-hydrogenated dicyclopentadiene resin): DCPD resin manufactured by Tokyo Chemical Industry Co., Ltd. (product code DO443, non-hydrogenated DCPD resin, softening point: 140°C, content of dicyclopentadiene-derived units: 100% by mass) Resin 4 (dicyclopentadiene-aromatic compound copolymer resin): Oppa PR-395 manufactured by Exxon Mobil (aromaticity: 9.9% by mass, softening point: 118°C, Mw: 600) Wax: Ozoace wax manufactured by Nippon Seiro Co., Ltd. Stearic acid: NOF Corporation, Tsubaki Zinc oxide: Zinc oxide type 2 manufactured by Mitsui Mining & Smelting Co., Ltd. Antioxidant 1: Nocrac 6C (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD)) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Antioxidant 2: Nocrac RD (2,2,4-trimethyl-1,2-dihydroquinoline polymer) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Sulfur: HK-200-5 (powdered sulfur containing 5% oil) manufactured by Hosoi Chemical Industry Co., Ltd. Vulcanization accelerator 1: Noccela CZ (N-cyclohexyl-2-benzothiazolyl sulfenamide) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Vulcanization accelerator 2: Noccelaer D (N,N'-diphenylguanidine) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0133] Examples and Comparative Examples According to the compounding formulations shown in Tables 1 to 3, chemicals other than sulfur and vulcanization accelerator were kneaded for 4 minutes at 165°C using a Banbury mixer to obtain a kneaded product. Next, sulfur and vulcanization accelerator were added to the kneaded product using an open roll, and the mixture was kneaded at 80°C for 4 minutes to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition was extruded into a tread shape, and then laminated together with other tire components on a tire building machine to form an unvulcanized tire. The tire was press-vulcanized at 150°C for 10 minutes to obtain a test tire (tire size: 205 / 55R16).

[0134] The following evaluations were carried out using the obtained test tires. The results are shown in Tables 1 to 3. The reference comparative example in Table 1 was designated Comparative Example 1-1, the reference comparative example in Table 2 was designated Comparative Example 2-1, and the reference comparative example in Table 3 was designated Comparative Example 3-1.

[0135] <Chipping resistance during high-speed driving> The test tire was mounted on a Japanese-made FF vehicle and driven at a speed of 80 km / h, and the distance traveled until chipping occurred in the tire tread was measured. The results were expressed as an index, with the reference comparative example being set at 100. The larger the index, the longer the distance traveled until chipping occurred, indicating better chipping resistance during high-speed driving.

[0136] [Table 1]

[0137] [Table 2]

[0138] [Table 3]

[0139] From Tables 1 to 3, it was found that the examples containing an elastomer component, at least one liquid plasticizer selected from the group consisting of liquid rubber, liquid resin, and ester-based plasticizer, and a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene-based resin can improve chipping resistance during high-speed running.

[0140] Furthermore, a comparison between Example 1-2 and Comparative Examples 1-1 to 1-3, a comparison between Example 2-2 and Comparative Examples 2-1 to 2-3, and a comparison between Example 3-2 and Comparative Examples 3-1 to 3-3 revealed that chipping resistance during high-speed running can be synergistically improved by using at least one liquid plasticizer selected from the group consisting of liquid rubber, liquid resin, and ester-based plasticizers in combination with a dicyclopentadiene-aromatic compound copolymer resin and / or a hydrogenated dicyclopentadiene-based resin.

Claims

1. an elastomer component containing styrene butadiene rubber and butadiene rubber; Silica and a mercapto-based silane coupling agent; at least one liquid plasticizer selected from the group consisting of liquid rubber, liquid resin, and ester-based plasticizer; dicyclopentadiene-aromatic compound copolymer resin and / or hydrogenated dicyclopentadiene resin, (total amount of dicyclopentadiene-aromatic compound copolymer resin and hydrogenated dicyclopentadiene resin) / total amount of the liquid plasticizer is 0.1 to 10, the total amount of silica mixed / the total amount of the liquid plasticizer mixed is 1.0 to 30, A tire (excluding the tire shown in (1-3) below) having a tire component using a tire composition (excluding the compositions shown in (1-1) to (1-2) below) for tread use. (1-1) A composition containing 50 phr of dicyclopentadiene-aromatic compound copolymer resin (Escorez 5600: manufactured by Exxon) and 10 phr of sunflower oil oleate per 100 phr of the rubber component. (1-2) A composition containing 34 phr of dicyclopentadiene-aromatic compound copolymer resin (Escorez 5600: manufactured by Exxon) and 8 phr of sunflower oil oleate per 100 phr of the rubber component. (1-3) A tire, two beads (20) adapted to contact a mounting rim, each of said beads having at least one annular reinforcing structure (70) defining a mid-plane (200) perpendicular to the rotational axis (2) of said tire and equidistant from said annular reinforcing structure of each bead; two sidewalls (30) as radially outward extensions of the bead, which merge into a crown comprising a crown reinforcement (80, 90), on the radially upper side of which rests a subtread (35) extending over the entire axial width of the crown reinforcement, and on the upper side of the subtread itself rests a tread (40) with a tread pattern formed by convex elements, the tread having, in each radial cross section, a first axial edge (45) and a second axial edge (46); and The tread is a central portion (I) made of at least one first rubber compound, extending on each side of said central plane in each radial cross section between a first axial end and a second axial end, said central portion having at least one circumferential rib (121-123) formed of a plurality of blocks (1210) separated by sipes, the average distance separating two adjacent blocks being less than 0.8 mm, and the number of said blocks being equal to or greater than 100; a first lateral portion (II) made of at least one second rubber compound extending from the first axial edge (45) of the tread to the first axial end of the central portion, the first lateral portion having at least one circumferential rib (131) formed by a plurality of blocks (1310) separated by sipes, the average distance separating two adjacent blocks being greater than 0.8 mm and less than 5 mm, the number of these blocks being less than the number of blocks constituting the at least one circumferential rib of the central portion; a second lateral portion (III) made of at least one third rubber compound extending from the second axial edge (46) of the tread to the second axial end of the central portion, the second lateral portion having at least one circumferential rib (141) formed by a plurality of blocks (1410) separated by sipes, the average distance separating two adjacent blocks being greater than 0.8 mm and less than 5 mm, the number of these blocks being less than the number of blocks constituting the at least one circumferential rib of the central portion; and the at least one second and third rubber compound has a tan δ value of less than 0.25 at a temperature of 23°C, a frequency of 10 Hz and an elongation of 10%; A tire wherein the complex modulus G*(T) of the at least one first rubber compound is greater than the complex modulus G*(T) of the at least one second and third rubber compounds at any temperature T greater than or equal to 0°C and less than or equal to 60°C.

2. 2. The tire according to claim 1, wherein (the total amount of dicyclopentadiene-aromatic compound copolymer resin and hydrogenated dicyclopentadiene resin) / the total amount of said liquid plasticizer is 1.1 to 1.

5.

3. 3. The tire according to claim 1, wherein the amount of silica blended is 5 to 200 parts by mass per 100 parts by mass of the elastomer component.

4. The tire according to any one of claims 1 to 3, wherein the total amount of the dicyclopentadiene-aromatic compound copolymer resin and the hydrogenated dicyclopentadiene resin is 80 parts by mass or less per 100 parts by mass of the elastomer component.

5. The tire according to any one of claims 1 to 4, which is a tire for a passenger car.

6. The tire according to any one of claims 1 to 5, wherein the tire component is a tread.

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