Elastomer composition and tire

Abstract

To provide an elastomer composition which improves overall performance of fuel economy, wear resistance on a wet road surface, and wet grip performance, and a tire using the same.SOLUTION: The elastomer composition contains an elastomer component, silica, carbon black, and a functionalized resin having a functional group containing at least one element selected from the group consisting of oxygen, silicon and nitrogen. A polymer content (PC), a carbon black content (BC), an acetone extractable content (AE), and an ash content (Ash) satisfy the following inequalities (i) and (ii): (i) when Ash+BC>PC, Ash+BC-PC≤AE; and (ii) when Ash+BC≤PC, AE+Ash≤PC and BC≤AE.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Tires are required to have various performance characteristics, such as low fuel consumption, wear resistance, and grip performance, and improvements are being made to these characteristics. In recent years, there has also been a demand for improvements in fuel consumption and wear resistance on wet roads. Summary of the Invention [Problem to be solved by the invention]

[0003] An object of the present invention is to solve the above problems and to provide an elastomer composition that improves overall performance, including fuel economy, abrasion resistance on wet road surfaces, and wet grip performance, and a tire using the same. [Means for solving the problem]

[0004] The present invention relates to an elastomer composition comprising an elastomer component, silica, carbon black, and a functionalized resin having a functional group containing at least one element selected from the group consisting of oxygen, silicon, and nitrogen, wherein the polymer content (PC), carbon black content (BC), acetone extractables (AE), and ash content (Ash) satisfy the following formulas (i) and (ii): (i) If Ash+BC>PC, then Ash+BC-PC≦AE (ii) If Ash + BC ≤ PC, then AE + Ash ≤ PC and BC ≤ AE

[0005] The silica has a nitrogen adsorption specific surface area of ​​180 m 2 It is preferable that the silica content is at least 1 / g.

[0006] The AE is preferably less than 20% by mass.

[0007] The elastomer component preferably contains two or more types of elastomer components, and at least one of the elastomer components is preferably an isoprene-based rubber or a butadiene rubber.

[0008] The content of the styrene-butadiene rubber in 100% by mass of the elastomer component is preferably 10 to 90% by mass.

[0009] The polymer backbone of the functionalized resin is preferably at least one selected from the group consisting of solid styrene-based resins, coumarone-indene resins, terpene-based resins, pt-butylphenol acetylene resins, acrylic resins, dicyclopentadiene-based resins, C5-based petroleum resins, C9-based petroleum resins, and C5C9-based petroleum resins.

[0010] The content of the functionalized resin is preferably 3 to 35 parts by mass relative to 100 parts by mass of the elastomer component.

[0011] (i) In the case where Ash+BC>PC, the content of oil is 10 to 90 parts by mass per 100 parts by mass of the elastomer component, (ii) When Ash+BC≦PC, the content of oil is preferably 20 parts by mass or less per 100 parts by mass of the elastomer component.

[0012] The present invention relates to a tire having a rubber layer 1 made of the elastomer composition and a rubber layer 2 adjacent to the rubber layer 1 radially inward, wherein the difference in acetone extractables (AE) between the rubber layer 1 and the rubber layer 2 is within 10% by mass.

[0013] The tire preferably has a tread negative ratio of 50% or less. [Effects of the Invention]

[0014] According to the present invention, the elastomer composition contains an elastomer component, silica, carbon black, and a functionalized resin having a functional group containing at least one element selected from the group consisting of oxygen, silicon, and nitrogen, and satisfies the above formulas (i) and (ii), thereby making it possible to improve the overall performance of fuel economy, abrasion resistance on wet road surfaces, and wet grip performance. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a cross-sectional view showing a portion of a pneumatic tire. DETAILED DESCRIPTION OF THE INVENTION

[0016] The elastomer composition of the present invention comprises an elastomer component, silica, carbon black, and a functionalized resin having a functional group containing at least one element selected from the group consisting of oxygen, silicon, and nitrogen, and satisfies the above formulas (i) and (ii). The elastomer composition can improve overall performance, including fuel economy, abrasion resistance on wet roads, and wet grip performance. At the same time, good wet grip performance can also be achieved.

[0017] The mechanism by which the above-mentioned effects are obtained is not clear, but is presumed to be as follows. Functionalized resins containing functional groups containing at least one element selected from the group consisting of oxygen, silicon, and nitrogen react or interact with silica to coat the silica surface, thereby suppressing friction around the silica and contributing to reduced heat generation. However, if the silica and functionalized resin are not dispersed sufficiently, agglomerates of silica and functionalized resin will form, generating heat due to friction between silica particles and between functionalized resin particles, resulting in poor fuel economy. Furthermore, when the functionalized resin comes into contact with a road surface cold enough to solidify (e.g., a wet road surface), it will form hard agglomerates of silica and functionalized resin, resulting in poor abrasion resistance. Therefore, dispersion of the silica and functionalized resin is considered to be extremely important when compounding the functionalized resin.

[0018] First, in the case of (i), Ash (ash content) + BC (carbon black content) > PC (polymer content), that is, when the filler is used in a relatively large amount, there will be more silica than elastomer, resulting in a high viscosity. Therefore, if we adjust Ash + BC - PC ≦ AE (acetone extractables), ensure AE, and lower the viscosity, we believe that dispersibility can be sufficiently improved. On the other hand, (ii) when Ash (ash content) + BC (carbon black content) ≦ PC (polymer content), that is, when the filler amount is relatively small, coating with the functionalized resin and the resulting dispersion effect can be expected, so sufficient dispersion can be achieved by adjusting AE + Ash ≦ PC and making the total amount of the opposing materials AE (oil, etc., lipophilic) and Ash (silica, etc., hydrophilic) less than PC. However, if AE (acetone extractables) becomes less than BC (carbon black content), the AE components (oil, etc.) will be captured by the carbon black, so it is thought that it is necessary to adjust BC ≦ AE and make the acetone extractables equal to or greater than the amount of carbon black. From the above, in the cases of (i) and (ii), by satisfying the corresponding formulas, it is possible to improve the dispersibility of silica and functionalized resin while blending functionalized resin, which is presumed to improve the overall performance of fuel economy, abrasion resistance on wet roads, and wet grip performance. It is also presumed that good wet grip performance can be obtained.

[0019] Thus, the elastomer composition, which is a formulation containing silica, carbon black, and a functionalized resin having a functional group containing at least one element selected from the group consisting of oxygen, silicon, and nitrogen, satisfies the following conditions: "(i) if Ash + BC > PC, then Ash + BC - PC ≦ AE," and "(ii) if Ash + BC ≦ PC, ​​then AE + Ash ≦ PC, ​​and BC ≦ AE." This solves the problem (purpose) of improving the overall performance of fuel economy, abrasion resistance on wet roads, and wet grip performance. In other words, the parameters "(i) if Ash + BC > PC, then Ash + BC - PC ≦ AE," and "(ii) if Ash + BC ≦ PC, ​​then AE + Ash ≦ PC, ​​and BC ≦ AE" do not define the problem (purpose). The problem of the present application is to improve the overall performance of fuel economy, abrasion resistance on wet roads, and wet grip performance, and a configuration that satisfies these parameters is used as a means to achieve this.

[0020] The elastomer composition has a polymer content (PC), a carbon black content (BC), an acetone extractable content (AE), and an ash content (Ash) that satisfy the following formulas (i) and (ii), where the units of PC, BC, AE, and Ash are % by mass. (i) If Ash+BC>PC, then Ash+BC-PC≦AE (ii) If Ash + BC ≤ PC, then AE + Ash ≤ PC and BC ≤ AE

[0021] (i) When Ash+BC>PC, Ash+BC-PC≦AE, but (Ash+BC-PC) / AE is preferably 0.50 or less, more preferably 0.30 or less, even more preferably 0.23 or less, and particularly preferably 0.18 or less. The lower limit is preferably 0.01 or more, more preferably 0.03 or more, and even more preferably 0.05 or more. Within the above range, the effect tends to be better.

[0022] (i) When Ash + BC > PC, PC is preferably 20% by mass or more, more preferably 25% by mass or more, even more preferably 30% by mass or more, and particularly preferably 32% by mass or more. The upper limit is preferably 55% by mass or less, more preferably 48% by mass or less, even more preferably 41% by mass or less, and particularly preferably 37% by mass or less. Within the above range, the effect tends to be better.

[0023] (i) When Ash + BC > PC, BC is preferably 1.0% by mass or more, more preferably 1.8% by mass or more, even more preferably 2.5% by mass or more, and particularly preferably 3.0% by mass or more. The upper limit is preferably 10.0% by mass or less, more preferably 7.0% by mass or less, even more preferably 6.0% by mass or less, and particularly preferably 5.0% by mass or less. Within the above range, the effect tends to be more favorable.

[0024] (i) When Ash + BC > PC, AE is preferably 8% by mass or more, more preferably 10% by mass or more, even more preferably 13% by mass or more, and particularly preferably 15% by mass or more. The upper limit is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 21% by mass or less, and particularly preferably less than 20% by mass. Within the above range, the effect tends to be more favorable. In particular, when AE is adjusted to less than 20% by mass, slippage during kneading can be prevented and poor dispersion of silica, resin, etc. can be more effectively suppressed, preventing the formation of silica and resin aggregates and effectively suppressing heat generation due to friction between silica particles and between resin particles. Therefore, deterioration of fuel economy is effectively suppressed, and it is presumed that the overall performance of fuel economy, wear resistance on wet roads, and wet grip performance is significantly (synergistically) improved.

[0025] (i) When Ash + BC > PC, Ash is preferably 30% by mass or more, more preferably 36% by mass or more, even more preferably 37% by mass or more, and particularly preferably 38% by mass or more. The upper limit is preferably 50% by mass or less, more preferably 45% by mass or less, even more preferably 42% by mass or less, and particularly preferably 40% by mass or less. Within the above range, the effect tends to be better.

[0026] (ii) When Ash + BC ≦ PC, ​​AE + Ash ≦ PC, ​​but (AE + Ash) / PC is preferably 0.97 or less, more preferably 0.90 or less, even more preferably 0.80 or less, and particularly preferably 0.76 or less. The lower limit is preferably 0.50 or more, more preferably 0.67 or more, even more preferably 0.70 or more, and particularly preferably 0.71 or more. Within the above range, the effect tends to be better.

[0027] (ii) When Ash + BC ≦ PC, ​​BC ≦ AE, but BC / AE is preferably 0.53 or less, more preferably 0.50 or less, even more preferably 0.34 or less, and particularly preferably 0.320 or less. The lower limit is preferably 0.05 or more, more preferably 0.08 or more, even more preferably 0.10 or more, and particularly preferably 0.11 or more. Within the above range, the effect tends to be better.

[0028] (ii) When Ash + BC ≦ PC, ​​PC is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 55% by mass or more, and particularly preferably 57% by mass or more. The upper limit is preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less, and particularly preferably 65% ​​by mass or less. Within the above range, the effect tends to be better.

[0029] (ii) When Ash + BC ≦ PC, ​​BC is preferably 1.0 mass% or more, more preferably 1.5 mass% or more, even more preferably 1.7 mass% or more, and particularly preferably 1.8 mass% or more. The upper limit is preferably 7.0 mass% or less, more preferably 5.0 mass% or less, even more preferably 3.6 mass% or less, and particularly preferably 2.4 mass% or less. Within the above range, the effect tends to be more favorable.

[0030] (ii) When Ash + BC ≦ PC, ​​AE is preferably 5% by mass or more, more preferably 7% by mass or more, even more preferably 10% by mass or more, and particularly preferably 16% by mass or more. The upper limit is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 22% by mass or less, and particularly preferably less than 20% by mass. Within the above range, the effect tends to be more favorably obtained. In particular, when AE is adjusted to less than 20% by mass, it is presumed that, as described above, the overall performance of fuel economy, wear resistance on wet roads, and wet grip performance is significantly (synergistically) improved.

[0031] (ii) When Ash + BC ≦ PC, ​​Ash is preferably 20% by mass or more, more preferably 25% by mass or more, even more preferably 28% by mass or more, and particularly preferably 31% by mass or more. The upper limit is preferably 37% by mass or less, more preferably 35% by mass or less, even more preferably 33% by mass or less, and particularly preferably 32% by mass or less. Within the above range, the effect tends to be better.

[0032] The physical properties of the elastomer composition are measured by the following methods. First, the acetone extractables (AE) of the elastomer composition (sample) are measured by the method for measuring acetone extractables in accordance with JIS K 6229:2015 (unit: mass % of the elastomer composition (sample)). The polymer content (PC) is calculated from the weight loss (mass) when the sample remaining after the acetone extraction is heated in nitrogen (from room temperature to 750°C) in accordance with JIS K6226-1:2003 to pyrolyze and vaporize the organic matter (unit: mass% in the elastomer composition (sample)). The carbon black content (BC) is calculated from the weight loss (mass) when the sample after the thermal decomposition and vaporization is oxidatively burned by heating in air (unit: mass % in the elastomer composition (sample)). The ash content (Ash) is calculated from the mass of the components (ash content) that do not burn in the oxidative combustion (unit: mass % in the elastomer composition (sample)). From the above definitions, the total of AE, PC, BC, and Ash is 100 mass %.

[0033] Methods known to those skilled in the art can be used to adjust AE, PC, BC, and Ash. For example, AE tends to increase as the amount of softeners such as oil in the elastomer composition increases. PC tends to increase as the amount of elastomer components in the elastomer composition increases. BC tends to increase as the amount of carbon black in the elastomer composition increases. Ash tends to increase as the amount of components that do not burn in oxidative combustion, such as silica, in the elastomer composition increases.

[0034] (Elastomer component) In the elastomer composition, for example, diene rubber can be used as the elastomer component. Examples of diene rubber include isoprene rubber, butadiene rubber (BR), styrene butadiene rubber (SBR), styrene isoprene butadiene rubber (SIBR), ethylene propylene diene rubber (EPDM), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR). Other examples include butyl rubber and fluororubber.

[0035] The diene rubber may be an unmodified diene rubber or a modified diene rubber. The modified diene rubber may be any diene rubber having a functional group that interacts with a filler such as silica. Examples include terminal-modified diene rubbers (terminal-modified diene rubbers having the functional group at the terminal) in which at least one terminal of the diene rubber has been modified with a compound (modifier) ​​having the functional group, main-chain-modified diene rubbers having the functional group at the main chain, main-chain-terminal-modified diene rubbers having the functional group at the main chain and at the terminals (for example, main-chain-terminal-modified diene rubbers having the functional group at the main chain and at least one terminal modified with the modifier), and terminal-modified diene rubbers modified (coupled) with a polyfunctional compound having two or more epoxy groups in the molecule and having a hydroxyl group or epoxy group introduced therein.

[0036] 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, 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 the 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), and an alkoxysilyl group (preferably an alkoxysilyl group having 1 to 6 carbon atoms) are preferred.

[0037] The elastomer component may also include a thermoplastic elastomer, such as an olefin-based thermoplastic elastomer, a styrene-based thermoplastic elastomer (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), or styrene-butadiene-butylene-styrene block copolymer (SBBS)), a vinyl chloride-based thermoplastic elastomer, a urethane-based thermoplastic elastomer, a polyamide-based thermoplastic elastomer, a polyester-based thermoplastic elastomer, or a fluorine-based thermoplastic elastomer.

[0038] Among the elastomer components, SBR, BR, and isoprene-based rubber are preferred from the viewpoint of overall performance, including fuel economy, abrasion resistance on wet road surfaces, and wet grip performance. The elastomer component contains two or more types of elastomer components, and the elastomer components preferably contain isoprene-based rubber and / or BR, and more preferably contain isoprene-based rubber and / or BR and SBR. The elastomer components may be used alone or in combination of two or more. When isoprene-based rubber and / or BR is used, the overall performance, including fuel economy, abrasion resistance on wet road surfaces, and wet grip performance, is more significantly improved (synergistically improved). This is presumably because the use of isoprene-based rubber and / or BR reduces the viscosity of the rubber, further improving the dispersion of resins and silica present ubiquitously in the rubber.

[0039] The SBR is not particularly limited, and examples thereof include emulsion-polymerized styrene-butadiene rubber (E-SBR), solution-polymerized styrene-butadiene rubber (S-SBR), etc. These may be used alone or in combination of two or more.

[0040] The styrene content of SBR is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. The styrene content is preferably 60% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. Within the above range, the effect tends to be more favorable. In this specification, the styrene content of SBR is 1 It is calculated by H-NMR measurement.

[0041] The vinyl content of the SBR is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 15 mol% or more. The vinyl content is preferably 75 mol% or less, more preferably 70 mol% or less. Within the above range, better effects tend to be obtained. The vinyl content (amount of 1,2-bonded butadiene units) can be measured by infrared absorption spectroscopy.

[0042] 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.

[0043] The SBR may be unmodified or modified, and the modified SBR may be modified SBR into which the same functional groups as those in modified diene rubbers have been introduced.

[0044] When the elastomer composition contains SBR, the content of SBR in 100% by mass of the elastomer component is preferably 10% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and particularly preferably 70% by mass or more. The upper limit is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less. Within the above range, better effects tend to be obtained.

[0045] The BR is not particularly limited, and examples thereof include high-cis BR with a high cis content, BR containing syndiotactic polybutadiene crystals, and BR synthesized using a rare earth catalyst (rare earth BR). These may be used alone or in combination of two or more. Among these, high-cis BR with a cis content of 90% by mass or more is preferred because it improves wear resistance.

[0046] The BR may be unmodified or modified. The modified BR may be a modified BR into which the same functional group as that of the modified diene rubber has been introduced.

[0047] When the elastomer composition contains BR, the content of BR in 100% by mass of the elastomer component is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more. The upper limit is preferably 60% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. Within the above range, better effects tend to be obtained.

[0048] As the BR, for example, products from Ube Industries, Ltd., JSR Corporation, Asahi Kasei Corporation, Nippon Zeon Corporation, etc. can be used.

[0049] 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 rubber industry. IRs are not particularly limited, and examples of IRs such as IR2200 are commonly used in the rubber 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.

[0050] When the elastomer composition contains an isoprene-based rubber, 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, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more. The upper limit is preferably 60% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. Within the above range, better effects tend to be obtained.

[0051] (filler) The elastomer composition contains silica and carbon black as fillers. Other fillers that can be used include materials known in the rubber field, such as calcium carbonate, talc, alumina, clay, aluminum hydroxide, aluminum oxide, and mica; and poorly dispersible fillers.

[0052] In the above elastomer composition, when (i) Ash + BC > PC, the filler content (total filler content) is preferably 80 parts by mass or more, more preferably 100 parts by mass or more, even more preferably 115 parts by mass or more, and particularly preferably 135 parts by mass or more, per 100 parts by mass of the elastomer component. The upper limit is preferably 200 parts by mass or less, more preferably 170 parts by mass or less, and even more preferably 150 parts by mass or less. Within the above range, better effects tend to be obtained.

[0053] In the above elastomer composition, when (ii) Ash + BC ≦ PC, ​​the filler content (total filler content) is preferably 30 parts by mass or more, more preferably 50 parts by mass or more, and even more preferably 75 parts by mass or more, per 100 parts by mass of the elastomer component. The upper limit is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, even more preferably 110 parts by mass or less, and particularly preferably 105 parts by mass or less. Within the above range, better effects tend to be obtained.

[0054] Usable silica includes, for example, dry-process silica (anhydrous silica) and wet-process silica (hydrated silica). Among them, wet-process silica is preferred because it has a large number of silanol groups. Examples of silica that can be used include products from Degussa, Rhodia, Tosoh Silica, Solvay Japan, and Tokuyama.

[0055] The nitrogen adsorption specific surface area (N2SA) of the silica is preferably 70 m 2 / g or more, more preferably 140m 2 / g or more, more preferably 160m 2 / g or more, particularly preferably 180m 2 The upper limit of the N2SA of silica is not particularly limited, but is preferably 300 m 2 / g or less, more preferably 250m 2 / g or less, more preferably 230m 2 Within the above range, the effect tends to be better. 2 When silica having a particle size of 1 / g or more is used, the abrasion resistance on wet grip road surfaces is improved more significantly (synergistically improved). This is presumably because, although it is generally difficult to ensure the dispersibility of such fine particle silica, the effect of improving the dispersibility of silica by blending the functionalized resin is enhanced. The N2SA of silica is a value measured by the BET method in accordance with ASTM D3037-93.

[0056] In the above elastomer composition, when (i) Ash + BC > PC, the content of silica is preferably 80 parts by mass or more, more preferably 100 parts by mass or more, even more preferably 110 parts by mass or more, and particularly preferably 130 parts by mass or more, per 100 parts by mass of the elastomer component. The upper limit is preferably 200 parts by mass or less, more preferably 170 parts by mass or less, and even more preferably 150 parts by mass or less. Within the above range, better effects tend to be obtained.

[0057] In the above elastomer composition, when (ii) Ash + BC ≦ PC, ​​the content of silica is preferably 30 parts by mass or more, more preferably 50 parts by mass or more, and even more preferably 70 parts by mass or more, per 100 parts by mass of the elastomer component. The upper limit is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, even more preferably 110 parts by mass or less, and particularly preferably 100 parts by mass or less. Within the above range, better effects tend to be obtained.

[0058] When silica is contained, a silane coupling agent may be blended together with the silica. The silane coupling agent that can be used is not particularly limited and may be any silane coupling agent that has conventionally been used in combination with silica in the rubber industry, 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-triethoxysilylbutyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(2-trimethoxysilylethyl)disulfide, bis(4-trimethoxysilylbutyl)disulfide, 3-triethoxysilylpropyl Examples of such compounds include sulfide-based compounds such as trimethoxysilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, and 3-triethoxysilylpropyl methacrylate monosulfide; mercapto-based compounds such as 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and Momentive's NXT and NXT-Z; 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 include those from Degussa, Momentive, Shin-Etsu Silicone Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azumax Co., Ltd., and Dow Corning Toray Co., Ltd. These may be used alone or in combination of two or more. Of these, sulfide-based and mercapto-based products are preferred.

[0059] The elastomer composition does not necessarily need to contain a silane coupling agent. Even if it does not contain a silane coupling agent, the above effects can be obtained well due to the action and effect of the functionalized resin described below. When a silane coupling agent is blended, the content is preferably 3 parts by mass or more, more preferably 6 parts by mass or more, per 100 parts by mass of silica. The content is preferably 20 parts by mass or less, more preferably 15 parts by mass or less. Within the above range, the effects tend to be obtained better.

[0060] Usable carbon blacks 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. Commercially available carbon blacks include those from Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin-Nichika Carbon Co., Ltd., and Columbia Carbon Co., Ltd.

[0061] The nitrogen adsorption specific surface area (N2SA) of carbon black is 50m 2 / g or more is preferable, and 80m 2 / g or more is more preferable, and 100m 2 / g or more is more preferable. 2 / g or less is preferable, and 150m 2 / g or less is more preferable, and 130m 2 Within the above range, the effect tends to be better. The nitrogen adsorption specific surface area of ​​carbon black can be determined according to JIS K6217-2:2001.

[0062] In the elastomer composition, the carbon black content is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and even more preferably 5 parts by mass or more, per 100 parts by mass of the elastomer component. The upper limit is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less. Within the above range, better effects tend to be obtained.

[0063] (plasticizer) The elastomer composition includes, as a plasticizer, a functionalized resin having a functional group containing at least one element selected from the group consisting of oxygen, silicon, and nitrogen.

[0064] Examples of the functional group containing at least one element selected from the group consisting of oxygen, silicon, and nitrogen include the functional groups described above that contain at least one element selected from the group consisting of oxygen, silicon, and nitrogen, and other known functional groups containing such elements. Among these, from the viewpoint of overall performance such as low fuel consumption, wear resistance on wet road surfaces, and wet grip performance, a group represented by -Si(R)3 (R may be the same or different and may be hydrogen, an organic element-containing group, an inorganic element-containing group, an organic element and an inorganic element-containing group, etc.) is preferred.

[0065] The functionalized resin can be produced by a known method, for example, by a slurry method, a metathesis method, etc. Specifically, for example, the functionalized resin can be produced by reacting a polymer that serves as the polymer backbone of the functionalized resin with a functional compound that can introduce a functional group containing at least one element selected from the group consisting of oxygen, silicon, and nitrogen, by a known method.

[0066] The polymer that forms the polymer backbone is not particularly limited and any polymer that can form a backbone can be used, and examples thereof include liquid resins (polymers that are liquid at 25°C) and solid resins (polymers that are solid at 25°C). Of these, solid resins are preferred. These polymers may be used alone or in combination of two or more.

[0067] The liquid resin is not particularly limited, but examples thereof include liquid aromatic vinyl polymers, coumarone-indene resins, indene resins, terpene resins, rosin resins, and hydrogenated products thereof. These may be used alone or in combination of two or more. Among these, liquid aromatic vinyl polymers are preferred from the viewpoint of overall performance, including low fuel consumption, wear resistance on wet roads, and wet grip performance.

[0068] Examples of liquid aromatic vinyl polymers include resins obtained by polymerizing α-methylstyrene and / or styrene, and specific examples include liquid resins such as a homopolymer of styrene, a homopolymer of α-methylstyrene, and a copolymer of α-methylstyrene and styrene.

[0069] Liquid coumarone-indene resins include resins 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, and vinyltoluene.

[0070] The liquid indene resin may be a liquid resin containing indene as a main monomer component that constitutes the skeleton (main chain) of the resin.

[0071] Examples of liquid terpene resins include resins obtained by polymerizing terpene compounds such as α-pinene, β-pinene, camphene, and dipentene, and liquid terpene resins typified by terpene phenol, which is a resin obtained from a terpene compound and a phenolic compound as raw materials.

[0072] Examples of liquid rosin resins include liquid rosin-based resins such as natural rosin, polymerized rosin, modified rosin, ester compounds thereof, and hydrogenated products thereof.

[0073] The solid resin (resin that is solid at 25°C) is not particularly limited, but examples thereof include solid styrene-based resins, coumarone-indene resins, terpene-based resins, pt-butylphenol acetylene resins, acrylic resins, dicyclopentadiene-based resins (DCPD-based resins), C5-based petroleum resins, C9-based petroleum resins, and C5C9-based petroleum resins. These may be used alone or in combination of two or more. Among these, solid styrene-based resins are preferred from the viewpoint of overall performance, including low fuel consumption, wear resistance on wet road surfaces, and wet grip performance.

[0074] The solid styrene-based resin is a solid polymer using a styrene-based monomer as a constituent monomer, and examples thereof include polymers obtained by polymerizing a styrene-based monomer as the main component (50% by mass or more).Specific examples include homopolymers obtained by polymerizing each of styrene-based monomers (styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, etc.) alone, copolymers obtained by copolymerizing two or more types of styrene-based monomers, and copolymers of a styrene-based monomer and another monomer copolymerizable therewith. Examples of other monomers include acrylonitriles such as acrylonitrile and methacrylonitrile, unsaturated carboxylic acids such as acrylic acid and methacrylic acid, unsaturated carboxylic acid esters such as methyl acrylate and methyl methacrylate, dienes such as chloroprene and butadiene isoprene, olefins such as 1-butene and 1-pentene, α,β-unsaturated carboxylic acids such as maleic anhydride or acid anhydrides thereof, and the like.

[0075] The solid coumarone-indene resin may be a solid resin having the same structural units as the liquid coumarone-indene resin described above.

[0076] Examples of solid terpene resins include polyterpenes, terpene phenols, and aromatic-modified terpene resins. Examples of solid polyterpenes include terpene resins such as α-pinene resins, β-pinene resins, limonene resins, dipentene resins, and β-pinene / limonene resins made from terpene compounds, as well as solid resins such as hydrogenated terpene resins obtained by hydrogenating such terpene resins. Examples of solid terpene phenols include solid resins obtained by copolymerizing a terpene compound with a phenolic compound, and solid resins obtained by hydrogenating such resins, specifically solid resins obtained by condensing a terpene compound, a phenolic compound, and formalin. Examples of solid aromatic-modified terpene resins include solid resins obtained by modifying a terpene resin with an aromatic compound, and solid resins obtained by hydrogenating such resins.

[0077] The solid pt-butylphenol acetylene resin may be a solid resin obtained by subjecting pt-butylphenol and acetylene to a condensation reaction.

[0078] The solid acrylic resin is not particularly limited, and examples thereof include solvent-free acrylic solid resins. Examples of monomer components constituting the solid acrylic resin include (meth)acrylic acid, (meth)acrylic acid esters (alkyl esters, aryl esters, aralkyl esters, etc.), (meth)acrylamide, and (meth)acrylic acid derivatives such as (meth)acrylamide derivatives. Furthermore, aromatic vinyls such as styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene, and divinylnaphthalene may be used as monomer components constituting the solid acrylic resin, along with (meth)acrylic acid and (meth)acrylic acid derivatives. The solid acrylic resin may be a resin composed solely of (meth)acrylic components, or a resin containing components other than (meth)acrylic components. Furthermore, the solid acrylic resin may have a hydroxyl group, a carboxyl group, a silanol group, or the like.

[0079] The softening point of the solid resin constituting the polymer skeleton is preferably 160° C. or lower, more preferably 130° C. or lower, even more preferably 110° C. or lower, and particularly preferably 96° C. or lower. The lower limit is preferably 60° C. or higher, more preferably 70° C. or higher, even more preferably 80° C. or higher, and particularly preferably 85° C. or higher. Within the above range, better effects tend to be obtained. In this specification, the softening point of a solid 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.

[0080] The functional compound can be any compound into which a functional group containing at least one element selected from the group consisting of oxygen, silicon, and nitrogen can be introduced. Among these, compounds into which a functional group containing silicon can be introduced are preferred from the viewpoint of overall performance, including low fuel consumption, wear resistance on wet road surfaces, and wet grip performance.

[0081] Suitable examples of the functional compound include compounds represented by the following formula:

[0082] [ka] (In the formula, p represents an integer of 1 to 1000. R 11 and R 12 R are the same or different and each represents a monovalent hydrocarbon group which may have a substituent. 13 are the same or different and each represents a monovalent hydrocarbon group which may have a substituent.

[0083] p is preferably 5 or more, more preferably 10 or more, and even more preferably 20 or more, and is preferably 800 or less, more preferably 700 or less, and even more preferably 600 or less.

[0084] R 11 , R 12 , R 13 The monovalent hydrocarbon group, which may have a substituent, preferably has 1 to 20 carbon atoms. The number of carbon atoms is more preferably 2 or more, more preferably 14 or less, and even more preferably 12 or less. Examples of the monovalent hydrocarbon group, which may have a substituent, include substituted or unsubstituted alkyl groups and alkenyl groups. Examples of the alkyl group include methyl groups, ethyl groups, n-propyl groups, isopropyl groups, n-butyl groups, sec-butyl groups, tert-butyl groups, phenyl groups, and fluoroalkane groups. Examples of the alkenyl group include vinyl groups, allyl groups, 1-propenyl groups, and 1-methylethenyl groups.

[0085] Suitable examples of the functional compound include compounds represented by the following formula: [ka] (In the formula, q represents an integer of 2 to 40. R 21 are the same or different and represent monovalent hydrocarbon groups which may have a substituent.

[0086] q is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more, and is preferably 38 or less, more preferably 36 or less, and even more preferably 35 or less.

[0087] R 21 The monovalent hydrocarbon group, which may have a substituent, preferably has 1 to 20 carbon atoms. The number of carbon atoms is more preferably 2 or more, more preferably 14 or less, and even more preferably 12 or less. R 21 Specific examples of R 11 , R 12 , R 13 Examples of the monovalent hydrocarbon group include those similar to the optionally substituted monovalent hydrocarbon groups of the above.

[0088] Suitable examples of the functional compound include compounds represented by the following formula:

[0089] [ka] (In the formula, X may be the same or different and represents a nitrogen, oxygen, or sulfur atom. Y may be the same or different and represents a boron, nitrogen, oxygen, silicon or sulfur atom. R 31 are the same or different and each represents a hydrogen atom or an optionally substituted monovalent hydrocarbon group. R 32 are the same or different and each represents a divalent hydrocarbon group which may have a substituent. R 33 are the same or different and represent a hydrogen atom, a halogen atom, a sulfonate group, or a monovalent hydrocarbon group which may have a substituent. R 31 , R31 and R 33 may be joined together to form a mononuclear or polynuclear ring. R 34 represents a monovalent hydrocarbon group which may have a substituent. a, b, and c are the same or different and represent integers, and a+b+c=3. X and Y are the same or different, and r=2 when Y is a boron atom, r=2 when X or Y is a nitrogen atom, r=1 when X or Y is an oxygen atom or a sulfur atom, and r=3 when Y is a silicon atom.

[0090] X may be the same or different and is a nitrogen atom, an oxygen atom, or a sulfur atom, with an oxygen atom being preferred.

[0091] Y may be the same or different and is a boron atom, nitrogen atom, oxygen atom, silicon atom, or sulfur atom, with an oxygen atom being preferred.

[0092] R 31 , R 33 , R 34 The monovalent hydrocarbon group, which may have a substituent, preferably has 1 to 20 carbon atoms. The number of carbon atoms is more preferably 2 or more, more preferably 14 or less, and even more preferably 12 or less. R 31 , R 33 , R 34 Specific examples of R 11 , R 12 , R 13 Examples of the monovalent hydrocarbon group include those similar to the optionally substituted monovalent hydrocarbon groups of the above.

[0093] R 32The divalent hydrocarbon group, which may have a substituent, preferably has 1 to 20 carbon atoms. The number of carbon atoms is more preferably 2 or more, more preferably 14 or less, and even more preferably 12 or less. Examples of the divalent hydrocarbon group, which may have a substituent, include a substituted or unsubstituted alkylene group and arylene group. Examples of the alkylene group include a methylene group, an ethylene group, and a trimethylene group. Examples of the arylene group include a phenylene group, a naphthylene group, and a biphenylene group.

[0094] a, b, and c are the same or different and represent an integer of 0 to 3, and a+b+c=3.

[0095] Suitable examples of the functional compound include compounds represented by the following formula:

[0096] [ka] (In the formula, X may be the same or different and represents a nitrogen, oxygen, or sulfur atom. Y may be the same or different and represents a boron, nitrogen, oxygen, silicon, or sulfur atom. R 31 are the same or different and each represents a hydrogen atom or an optionally substituted monovalent hydrocarbon group. R 32 are the same or different and each represents a divalent hydrocarbon group which may have a substituent. R 33 are the same or different and represent a hydrogen atom, a halogen atom, a sulfonate group, or a monovalent hydrocarbon group which may have a substituent. R 31 , R 31 and R 33 may be joined together to form a mononuclear or polynuclear ring. R 35 represents a divalent hydrocarbon group which may have a substituent. a, b, and c are the same or different and represent integers, and a+b+c=3. d, e, and f are the same or different and represent integers, and d+e+f=3. X and Y are the same or different, and r=2 when Y is a boron atom, r=2 when X or Y is a nitrogen atom, r=1 when X or Y is an oxygen atom or a sulfur atom, and r=3 when Y is a silicon atom.

[0097] X may be the same or different and is a nitrogen atom, an oxygen atom, or a sulfur atom, with an oxygen atom being preferred.

[0098] Y may be the same or different and is a boron atom, nitrogen atom, oxygen atom, silicon atom, or sulfur atom, with an oxygen atom being preferred.

[0099] R 31 , R 33 The monovalent hydrocarbon group, which may have a substituent, preferably has 1 to 20 carbon atoms. The number of carbon atoms is more preferably 2 or more, more preferably 14 or less, and even more preferably 12 or less. R 31 , R 33 Specific examples of R 11 , R 12 , R 13 Examples of the monovalent hydrocarbon group include those similar to the optionally substituted monovalent hydrocarbon groups of the above.

[0100] R 32 , R 35 The optionally substituted divalent hydrocarbon group preferably has 1 to 20 carbon atoms. The number of carbon atoms is more preferably 2 or more, more preferably 14 or less, and even more preferably 12 or less. 32 , R 35 Specific examples of R 32 Examples of the divalent hydrocarbon group include those similar to the optionally substituted divalent hydrocarbon group of the above.

[0101] a, b, and c are the same or different and represent an integer of 0 to 3, and a+b+c=3. d, e, and f are the same or different and represent an integer of 0 to 3, and d+e+f=3.

[0102] Specific examples of the functional compound include vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinyldimethylethoxysilane, allyltrimethoxysilane, allylmethyldimethoxysilane, allyldimethylmethoxysilane, allyltriethoxysilane, allylmethyldiethoxysilane, allyldimethylethoxysilane, hexenyltrimethoxysilane, hexenylmethyldimethoxysilane, hexenyldimethylmethoxysilane, and hexenyltriethoxysilane. Silane, hexenylmethyldiethoxysilane, hexenyldimethylethoxysilane, octenyltrimethoxysilane, octenylmethyldimethoxysilane, octenyldimethylmethoxysilane, octenyltriethoxysilane, octenylmethyldiethoxysilane, octenyldimethylethoxysilane, norbornenylethyltrimethoxysilane, norbornenylethylmethyldimethoxysilane, norbornenylethyldimethylmethoxysilane, norbornenylethyltriethoxysilane, norbornenylethylmethyldiethoxysilane, norbornenyl Nylethyldimethylethoxysilane, (meth)acryloxypropyltrimethoxysilane, (meth)acryloxypropylmethyldimethoxysilane, (meth)acryloxypropyldimethylmethoxysilane, (meth)acryloxypropyltriethoxysilane, (meth)acryloxypropylmethyldiethoxysilane, (meth)acryloxypropyldimethylethoxysilane, (meth)acryloxytrimethoxysilane, (meth)acryloxymethylmethyldimethoxysilane, (meth)acryloxymethyldimethylmethoxysilane, (meth)acryloxy Examples of suitable silanes include dimethyltriethoxysilane, (meth)acryloxymethylmethyldiethoxysilane, (meth)acryloxymethyldimethylethoxysilane, (meth)acryloxyoctyltrimethoxysilane, (meth)acryloxyoctylmethyldimethoxysilane, (meth)acryloxyoctyldimethylmethoxysilane, (meth)acryloxyoctyltriethoxysilane, (meth)acryloxyoctylmethyldiethoxysilane, and (meth)acryloxyoctyldimethylethoxysilane. Among these, vinyltrimethoxysilane,Examples include vinyltriethoxysilane and (meth)acryloxypropyltrimethoxysilane. Of these, allyltriethoxysilane is preferred.

[0103] In the elastomer composition, the content of the functionalized resin is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, and particularly preferably 10 parts by mass or more, per 100 parts by mass of the elastomer component. The upper limit is preferably 35 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 25 parts by mass or less, and particularly preferably 20 parts by mass or less. Within the above range, better effects tend to be obtained.

[0104] The elastomer composition may further contain other plasticizers in addition to the functionalized resin. Examples of other plasticizers include, but are not limited to, oils, liquid plasticizers having liquid plasticity at 25°C, such as the liquid resins described above, and solid plasticizers having solid plasticity at 25°C, such as the solid resins described above. These plasticizers may be used alone or in combination.

[0105] In the above elastomer composition, when (i) Ash + BC > PC, the plasticizer content (total amount of the functionalized resin, liquid plasticizers such as oils and liquid resins other than the functionalized resins, and solid plasticizers such as solid resins other than the functionalized resins) is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 40 parts by mass or more, per 100 parts by mass of the elastomer component. Furthermore, the content is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less. Within the above range, better effects tend to be obtained.

[0106] In the above elastomer composition, when (ii) Ash + BC ≦ PC, ​​the plasticizer content (total amount of the functionalized resin, liquid plasticizers such as oils and liquid resins other than the functionalized resins, and solid plasticizers such as solid resins other than the functionalized resins) is preferably 3 parts by mass or more, more preferably 7 parts by mass or more, and even more preferably 10 parts by mass or more per 100 parts by mass of the elastomer component. Furthermore, the content is 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. Within the above range, better effects tend to be obtained.

[0107] In the liquid plasticizer, the oil is not particularly limited, and conventionally known oils can be used, such as process oils such as paraffinic process oil, aromatic process oil, naphthenic process oil, low PCA (polycyclic aromatic) process oil such as TDAE and MES, vegetable oil, and mixtures thereof. Among them, aromatic process oil is preferred in terms of abrasion resistance and fracture properties. Specific examples of the aromatic process oil include the Diana Process Oil AH series manufactured by Idemitsu Kosan Co., Ltd.

[0108] In the liquid plasticizer, examples of the liquid resin include those mentioned above.

[0109] In the above elastomer composition, when (i) Ash+BC>PC, the content of the liquid plasticizer (the total amount of liquid plasticizers such as the functionalized resin, oil, and liquid resins other than the functionalized resin that are liquid at 25°C) is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 30 parts by mass or more, per 100 parts by mass of the elastomer component. Furthermore, the content is preferably 90 parts by mass or less, more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less. Within the above range, better effects tend to be obtained. The oil content is also preferably in a similar range.

[0110] In the above elastomer composition, when (ii) Ash + BC ≦ PC, ​​the content of the liquid plasticizer (the total amount of liquid plasticizers such as the functionalized resin, oil, and liquid resins other than the functionalized resin that are liquid at 25°C) is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the elastomer component, and may even be 0 parts by mass. Within the above range, better effects tend to be obtained. The oil content is also preferably in a similar range.

[0111] In the solid plasticizer, examples of the solid resin include those mentioned above.

[0112] In the elastomer composition, the content of the solid plasticizer (the total amount of the functionalized resin that is solid at 25°C and solid plasticizers such as solid resins other than the functionalized resin) is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, and particularly preferably 10 parts by mass or more, per 100 parts by mass of the elastomer component. The upper limit is preferably 35 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 25 parts by mass or less, and particularly preferably 20 parts by mass or less. Within the above range, better effects tend to be obtained.

[0113] Examples of liquid plasticizers and solid plasticizers 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., ENEOS Corporation, Arakawa Chemical Industries, Ltd., and Taoka Chemical Co., Ltd.

[0114] (Other ingredients) The elastomer composition preferably contains an antioxidant from the viewpoints of crack resistance, ozone resistance, and the like.

[0115] The antioxidant is not particularly limited, but examples thereof 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, N,N'-di-2-naphthyl-p-phenylenediamine, and the like. Examples of suitable antioxidants include p-phenylenediamine antioxidants such as amines; 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. Among these, p-phenylenediamine antioxidants and quinoline antioxidants are preferred, with polymers of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine and 2,2,4-trimethyl-1,2-dihydroquinoline being more preferred. Commercially available products include those from Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., and Flexis.

[0116] The content of the antioxidant is preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more, per 100 parts by mass of the elastomer component. By using an amount equal to or greater than the lower limit, sufficient ozone resistance tends to be obtained. The content is preferably 7.0 parts by mass or less, more preferably 4.0 parts by mass or less. By using an amount equal to or less than the upper limit, a good appearance tends to be obtained.

[0117] The elastomer composition may contain stearic acid, and the content of stearic acid is preferably 0.5 to 10 parts by mass or more, and more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the elastomer component.

[0118] As the stearic acid, conventionally known products can be used, for example, products available from NOF Corporation, Kao Corporation, Fujifilm Wako Pure Chemical Industries, Ltd., Chiba Fatty Acid Co., Ltd., etc.

[0119] The elastomer composition preferably contains zinc oxide, with the content of zinc oxide being preferably 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of the elastomer component.

[0120] 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.

[0121] The elastomer composition may contain wax, and the wax content is preferably 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of the elastomer component.

[0122] The wax is not particularly limited, and examples thereof include petroleum waxes, natural waxes, etc. Synthetic waxes obtained by refining or chemically treating multiple waxes can also be used. These waxes may be used alone or in combination of two or more types.

[0123] Examples of petroleum-based waxes include paraffin wax and microcrystalline wax. Natural waxes are not particularly limited as long as they are derived from non-petroleum resources, and examples include plant-based waxes such as candelilla wax, carnauba wax, Japan wax, rice wax, and jojoba wax; animal-based waxes such as beeswax, lanolin, and spermaceti; mineral-based waxes such as ozokerite, ceresin, and petrolactam; and refined products thereof. Commercially available products include those from Ouchi Shinko Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., and Seiko Chemical Co., Ltd. The wax content can be appropriately determined from the standpoints of ozone resistance and cost.

[0124] The elastomer composition may contain sulfur in order to form appropriate crosslinked chains in the polymer chains and to provide a good balance of the above-mentioned performances.

[0125] The sulfur content is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, and even more preferably 0.7 part by mass or more, per 100 parts by mass of the elastomer component, and is preferably 6.0 parts by mass or less, more preferably 4.0 parts by mass or less, and even more preferably 3.0 parts by mass or less.

[0126] 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. Commercially available products include those from Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Chemical Industry Co., Ltd., Flexis Corporation, Nippon Kanzuri Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. These may be used alone or in combination of two or more.

[0127] The elastomer composition may contain a vulcanization accelerator. The content of the vulcanization accelerator is not particularly limited and may be freely determined according to the desired vulcanization speed and crosslink density, but is usually 0.3 to 10 parts by mass, preferably 0.5 to 7 parts by mass, per 100 parts by mass of the elastomer component.

[0128] The type of vulcanization accelerator is not particularly limited, and commonly used ones can be used. Examples of the vulcanization accelerator include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, and N-cyclohexyl-2-benzothiazyl sulfenamide; 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-benzothiazole sulfenamide, Nt-butyl-2-benzothiazolyl sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, and N,N'-diisopropyl-2-benzothiazole sulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, di-orthotolylguanidine, and orthotolylbiguanidine. These may be used alone or in combination of two or more. Among them, sulfenamide vulcanization accelerators and guanidine vulcanization accelerators are preferred from the viewpoint of the balance of performance.

[0129] In addition to the above components, the elastomer composition may contain appropriate additives, such as mold release agents and pigments, which are commonly used in the application field.

[0130] The elastomer composition can be produced by a known method. For example, the components are kneaded using a rubber kneading device such as an open roll or a Banbury mixer, followed by crosslinking as necessary. The kneading conditions are as follows: the kneading temperature is usually 50 to 200°C, preferably 80 to 190°C, and the kneading time is usually 30 seconds to 30 minutes, preferably 1 minute to 30 minutes.

[0131] The tire components for which the elastomer composition is used are not particularly limited, but it can be suitably used in treads (and cap treads).

[0132] The elastomer composition can be suitably used for tires. Examples of tires include pneumatic tires and non-pneumatic tires, with pneumatic tires being preferred. The composition can be particularly suitably used as summer tires and winter tires (studless tires, snow tires, studded tires, etc.). Tires can be used for passenger car tires, large passenger car tires, large SUV tires, heavy-duty tires for trucks, buses, etc., light truck tires, motorcycle tires, racing tires (high-performance tires), etc.

[0133] A tire is manufactured by a conventional method using the elastomer composition. For example, an elastomer composition containing various materials is extruded in an unvulcanized state to match the shape of a tire component, and molded together with other tire components in a tire building machine by a conventional method to form an unvulcanized tire, which is then heated and pressurized in a vulcanizer to manufacture a tire.

[0134] An example of the tire includes a rubber layer 1 made of the elastomer composition and a rubber layer 2 adjacent to and radially inward of the rubber layer 1, wherein the difference in acetone extractables (AE) between the rubber layer 1 and the rubber layer 2 is within 10% by mass. The tire is excellent in overall performance, including low fuel consumption, wear resistance on wet road surfaces, and wet grip performance.

[0135] The mechanism by which the above-mentioned effects are obtained is not clear, but is presumed to be as follows. Plasticizers tend to migrate to adjacent components during driving, but this migration does not occur uniformly, leading to uneven hardness distribution. When there is a distribution where the silica aggregates locally hard and the resin aggregates locally soft, further migration can exacerbate the uneven distribution. Plasticizers contribute significantly to hardness, especially under low-temperature (wet) conditions. Therefore, by reducing the difference in acetone extractables (AE), the effect of suppressing wear on wet roads is enhanced, resulting in a significant (synergistic) improvement in overall performance, including fuel economy, wet road wear resistance, and wet grip performance.

[0136] An example of a tire will be described with reference to FIG. In Figure 1, the up-down direction is the radial direction of the tire 2, the left-right direction is the axial direction of the tire 2, and the direction perpendicular to the paper surface is the circumferential direction of the tire 2. The tread 4 includes a cap layer 30 and a base layer 28, and it is preferable that the cap layer 30 is made of the elastomer composition. In this case, the rubber layer adjacent to the radially inner side of the tire 2 is the base layer 28, and it is preferable that the difference in acetone extractables (AE) between the cap layer 30 (rubber layer 1) and the base layer (rubber layer 2) is 10% by mass or less. The smaller the difference in AE, the better, more preferably 5% by mass or less, even more preferably 3% by mass or less, and particularly preferably 1% by mass or less, and the difference may even be 0% by mass.

[0137] Although FIG. 1 shows an example of a two-layer tread 4 consisting of a cap layer 30 and a base layer 28, a single-layer tread 4 or a tread having a structure of three or more layers may also be used, and in either case, it is desirable that the outermost layer that comes into contact with the road surface is composed of the elastomer composition.

[0138] In the tire 2, each sidewall 6 extends substantially radially inward from an end of the tread 4. A radially outer portion of each sidewall 6 is joined to the tread 4. A radially inner portion of each sidewall 6 is joined to a clinch 10. Each sidewall 6 is made of crosslinked rubber that has excellent cut resistance and weather resistance. Each sidewall 6 prevents damage to the carcass 14.

[0139] Each wing 8 is located between the tread 4 and the sidewall 6. The wing 8 is joined to each of the tread 4 and the sidewall 6. The wing 8 is made of crosslinked rubber with excellent adhesive properties.

[0140] Each clinch 10 is located approximately radially inward of the sidewall 6. The clinches 10 are located axially outward of the beads 12 and the carcass 14. The clinches 10 are made of crosslinked rubber with excellent abrasion resistance.

[0141] Each bead 12 is located axially inside the clinch 10. The bead 12 includes a core 32 and an apex 34 extending radially outward from the core 32. The core 32 is ring-shaped and includes a wound inelastic wire. The wire is typically made of steel. The apex 34 tapers radially outward. The apex 34 is made of high-hardness crosslinked rubber.

[0142] The carcass 14 includes a carcass ply 36. In the tire 2, the carcass 14 is made up of one carcass ply 36. This allows for weight reduction.

[0143] In the tire 2, the carcass ply 36 is laid between the beads 12 on both sides and extends along the tread 4 and the sidewall 6. The carcass ply 36 is folded back from the inside to the outside in the axial direction around each core 32. This folding back forms a main portion 36a and a pair of folded back portions 36b in the carcass ply 36. That is, the carcass ply 36 includes the main portion 36a and the pair of folded back portions 36b.

[0144] Although not shown, the carcass ply 36 is made up of a large number of parallel cords and a topping rubber. The absolute value of the angle that each cord makes with respect to the equator plane is preferably 75° to 90°. In other words, the carcass 14 preferably has a radial structure. The cords are made of organic fibers. Examples of preferred organic fibers include polyester fibers, nylon fibers, rayon fibers, polyethylene naphthalate fibers, and aramid fibers.

[0145] The belt 16 is located radially inward of the tread 4. The belt 16 is laminated with the carcass 14. The belt 16 reinforces the carcass 14. The belt 16 is made up of an inner layer 38 and an outer layer 40. As is clear from FIG. 1 , the width of the inner layer 38 in the axial direction is slightly larger than the width of the outer layer 40. In this tire 2, the axial width of the belt 16 is preferably 0.6 times or more and 0.9 times or less the cross-sectional width of the tire 2 (see JATMA).

[0146] Although not shown, each of the inner layer 38 and the outer layer 40 is composed of a large number of parallel cords and a topping rubber. In other words, the belt 16 includes a large number of parallel cords. Each cord is inclined with respect to the equatorial plane. The absolute value of the inclination angle is generally 10° or more and 35° or less. The inclination direction of the cords of the inner layer 38 with respect to the equatorial plane is opposite to the inclination direction of the cords of the outer layer 40 with respect to the equatorial plane. A preferred material for the cords is steel. Organic fibers may be used for the cords. In this case, examples of the organic fibers include polyester fibers, nylon fibers, rayon fibers, polyethylene naphthalate fibers, and aramid fibers.

[0147] The band 18 is located radially outside the belt 16. In the axial direction, the band 18 has a width equal to the width of the belt 16. The band 18 may also have a width greater than the width of the belt 16.

[0148] Although not shown, the band 18 is made of a cord and a topping rubber. The cord is wound spirally. The band 18 has a so-called jointless structure. The cord extends substantially in the circumferential direction. The angle of the cord with respect to the circumferential direction is 5° or less, and even 2° or less. The cord restrains the belt 16, thereby suppressing lifting of the belt 16. The cord is made of organic fiber. Preferred organic fibers include nylon fiber, polyester fiber, rayon fiber, polyethylene naphthalate fiber, and aramid fiber.

[0149] The belt 16 and the band 18 form a reinforcing layer. The reinforcing layer may be formed of the belt 16 alone.

[0150] The inner liner 20 is located inside the carcass 14. The inner liner 20 is bonded to the inner surface of the carcass 14. The inner liner 20 is made of crosslinked rubber with excellent air barrier properties. A typical base rubber of the inner liner 20 is butyl rubber or halogenated butyl rubber. The inner liner 20 maintains the internal pressure of the tire 2.

[0151] Each chafer 22 is located near the bead 12. In this embodiment, the chafer 22 is made of cloth and rubber impregnated into the cloth. The chafer 22 may be integrated with the clinch 10. In this case, the material of the chafer 22 is the same as the material of the clinch 10.

[0152] In this tire 2, the tread 4 has main grooves 42 as the grooves 26. As shown in FIG. 1 , a plurality of main grooves 42, specifically three main grooves 42, are formed in the tread 4. These main grooves 42 are spaced apart in the axial direction. The three main grooves 42 formed in the tread 4 form four ribs 44 extending in the circumferential direction. In other words, the spaces between the ribs 44 constitute the main grooves 42.

[0153] Each main groove 42 extends in the circumferential direction. The main grooves 42 are continuous and uninterrupted in the circumferential direction. The main grooves 42 facilitate the drainage of water present between the road surface and the tire 2, for example, in rainy weather. This allows the tire 2 to maintain sufficient contact with the road surface even when the road surface is wet. The main grooves 42 contribute to the wet grip of the tire 2.

[0154] The tire preferably has a tread negative ratio of 50% or less. The negative ratio of the tread is preferably 40% or less, more preferably 35% or less, and even more preferably 30% or less. The negative ratio is preferably 5% or more, more preferably 10% or more, and even more preferably 15% or more. When the negative ratio is within the above range, better effects tend to be obtained. The negative ratio (negative ratio within the contact surface of the tread portion) is the ratio of the total groove area within the contact surface to the total area of ​​the contact surface.

[0155] The mechanism by which the above-mentioned effects are obtained is not clear, but is presumed to be as follows. If the groove area is large, the contact area with the road surface will be small, and the rubber blocks on the tread surface that are in contact with the road surface will move more, which may lead to the aggregation of resin and silica, and there is also the risk of cracks and wear caused by agglomerates that have been present since manufacturing.However, by adjusting the negative ratio to 50% or less, these problems can be prevented, and as a result, it is thought that there will be a significant (synergistic) improvement in the overall performance of fuel economy, wear resistance on wet roads, and wet grip performance. [Example]

[0156] The present invention will be specifically described based on examples, but the present invention is not limited to these examples.

[0157] The various chemicals used in the examples and comparative examples will be collectively described below. NR:TSR20 SBR: NS616 manufactured by Zeon Corporation (non-oil-extended SBR, styrene content 21% by mass, vinyl content 66 mol%, Tg -23°C, Mw 240,000) BR: BR150B (cis content: 97% by mass) manufactured by Ube Industries, Ltd. Carbon black: Diablack I (N220, N2SA114m) manufactured by Mitsubishi Chemical Corporation 2 / g, DBP 114ml / 100g) Silica 1: Ultrasil VN3 (N2SA175m) manufactured by Evonik Degussa 2 / g) Silica 2: Rhodia Zeosil Premium 200MP (N2SA220m 2 / g) Solid resin: SYLVARES SA85 (copolymer of α-methylstyrene and styrene) manufactured by Arizona Chemical Co., softening point: 85°C Oil: H&R VIVATEC 400 / 500 (TDAE oil) Functionalized resin 1: Synthesis Example 1 below Functionalized resin 2: Synthesis Example 2 below Wax: Ozoace 0355 manufactured by Nippon Seiro Co., Ltd. Antiaging agent: Antigen 6C (antiaging agent, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) manufactured by Sumitomo Chemical Co., Ltd. Stearic acid: Tsubaki (NOF Corporation) Zinc oxide: Two types of zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd. Sulfur: Powdered sulfur manufactured by Tsurumi 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 (DPG)) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0158] <Synthesis Example 1> Aluminum chloride and toluene were added to a glass flask purged with inert gas, and styrene and α-methylstyrene were added dropwise. The reaction mixture was then added dropwise to an isoprene / toluene solution to which allyltriethoxysilane had been added by the slurry method, and water was added to the reaction mixture to terminate the reaction. After repeating the process of removing the aqueous layer by separation, the organic layer obtained by separation was blown dry to volatilize the toluene, and then dried under reduced pressure to obtain a modified styrene-α-methylstyrene resin (functionalized resin 1).

[0159] <Synthesis Example 2> The polyterpene resin and toluene were placed in a flask and heated to 60°C while stirring. After dissolution, an isoprene / toluene solution to which allyltriethoxysilane had been added by the slurry method was added dropwise, followed by the addition of a ruthenium catalyst. After stirring at 60°C for 18 hours, the mixture was poured into methanol and the solid matter was removed. The removed solid matter was dried in a vacuum oven at 35°C for 16 hours to obtain a modified polyterpene resin (functionalized resin 2).

[0160] Examples and Comparative Examples According to the formulations shown in each table, materials other than sulfur and vulcanization accelerator were kneaded for 5 minutes at 150°C using a 1.7L Banbury mixer manufactured by Kobe Steel, Ltd. to obtain a kneaded mixture. Next, sulfur and vulcanization accelerator were added to the obtained kneaded mixture, and the mixture was kneaded for 5 minutes at 80°C using an open roll to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition was molded into a tread shape and laminated together with other tire components to form an unvulcanized tire. This was press-vulcanized for 12 minutes at 150°C to produce a test tire (size: 175 / 60R18).

[0161] The obtained test tires were used to measure and evaluate the following physical properties, and the results are shown in the tables. The reference comparative examples in Tables 1 and 2 were designated Comparative Examples 1-1 and 2-1, respectively.

[0162] <Amount of acetone extracted (AE amount)> For rubber test pieces cut out from the tread of the test tire, the amount of substance contained in the test piece that could be extracted with acetone was measured according to the method for measuring acetone extractables in accordance with JIS K 6229. Acetone extractable amount (mass%) = (mass of sample before extraction - mass of sample after extraction) / mass of sample before extraction × 100

[0163] <Polymer content (PC)> For the sample after acetone extraction in the acetone extractable amount (AE amount), the organic matter was pyrolyzed and vaporized by heating in nitrogen (from room temperature to 750°C) in accordance with JIS K6226-1:2003, and the weight loss (mass) was measured, and the PC (mass%) was calculated based on the result.

[0164] <Carbon black content (BC)> For the sample after pyrolysis and vaporization of the polymer amount (PC), the weight loss (mass) was measured when it was oxidized and burned by heating in air, and the BC (mass%) was calculated based on this.

[0165] <Ash content (Ash)> In the carbon black amount (BC), the mass of the component (ash content) that was not combusted in the oxidative combustion was measured, and Ash (mass %) was calculated based on this.

[0166] <Wet grip performance> Each test tire was fitted to all wheels of a vehicle (domestic FF 2000cc), and the braking distance from an initial speed of 100 km / h on a wet asphalt road surface was measured and expressed as an index (wet grip performance index) with the reference comparative example being set at 100. A higher index indicates a shorter braking distance and better wet grip performance.

[0167] <Fuel efficiency> Using a rolling resistance tester, the rolling resistance of each test tire was measured when it was run on a rim (15x6JJ), under an internal pressure (230 kPa), a load (3.43 kN), and at a speed (80 km / h), and the results were expressed as an index (fuel economy index) with the reference comparative example being set at 100. A higher index indicates lower rolling resistance and better fuel economy.

[0168] <Wear resistance on wet roads> Each test tire was mounted on all wheels of a vehicle (domestic FF 2000cc) and driven on a wet asphalt road surface, and the groove depth of the tire tread was measured after a driving distance of 8000 km. The driving distance when the tire groove depth decreased by 1 mm was calculated and expressed as an index (wet road wear resistance index) with the reference comparative example being set at 100. A higher index indicates a longer driving distance and better wear resistance on wet road surfaces.

[0169] [Table 1]

[0170] [Table 2]

[0171] The tires of the examples, which contained an elastomer component, silica, carbon black, and the functionalized resin and satisfied the formulas (i) and (ii), were excellent in overall performance of fuel economy, abrasion resistance on wet road surfaces, and wet grip performance (expressed as the sum of three indices: fuel economy, abrasion resistance and crack growth resistance on wet road surfaces, and wet grip performance).

[0172] Furthermore, when functionalized resins such as other solid styrene-based resins, terpene-based resins, coumarone-indene resins, pt-butylphenol acetylene resins, acrylic resins, dicyclopentadiene-based resins (DCPD-based resins), C5-based petroleum resins, C9-based petroleum resins, and C5C9-based petroleum resins were functionalized with allyltriethoxysilane or other functional compounds, the overall performance was also excellent. [Explanation of symbols]

[0173] 2. Pneumatic tires 4 Tread 6 Sidewall 8 Wing 10 Clinch 12 beads 14 Carcass 16 Belt 18 bands 20 Inner liner 22 Chafer 24 Tread surface 26 Groove 28 base layer 30 cap layers 32 cores 34 Apex 36 Carcass ply 36a Main part 36b Folded part 38 Inner layer 40 outer layer 42 Main groove 44 Ribs CL Equatorial plane of tire 2

Claims

1. The composition includes an elastomer component, silica, carbon black, and a functionalized resin having a silicon-containing functional group; the polymer backbone of the functionalized resin is at least one selected from the group consisting of solid styrene-based resins, coumarone-indene resins, terpene-based resins, p-t-butylphenol acetylene resins, acrylic resins, dicyclopentadiene-based resins, C5-based petroleum resins, C9-based petroleum resins, and C5C9-based petroleum resins; The polymer amount (PC), the carbon black amount (BC), the acetone extractable amount (AE), and the ash content (Ash) satisfy the following formulas (i) and (ii), The functionalized resin may contain, in the polymer backbone, one or more of vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinyldimethylethoxysilane, allyltrimethoxysilane, allylmethyldimethoxysilane, allyldimethylmethoxysilane, allyltriethoxysilane, allylmethyldiethoxysilane, allyldimethylethoxysilane, hexenyltrimethoxysilane, hexenylmethyldimethoxysilane, hexenyl ... Methyl methoxysilane, hexenyl triethoxysilane, hexenyl methyl diethoxysilane, hexenyl dimethyl ethoxysilane, octenyl trimethoxysilane, octenyl methyl dimethoxysilane, octenyl dimethyl methoxysilane, octenyl triethoxysilane, octenyl methyl diethoxysilane, octenyl dimethyl ethoxysilane, norbornenyl ethyl trimethoxysilane, norbornenyl ethyl methyl dimethoxysilane, norbornenyl ethyl dimethyl methoxysilane, norbornenyl ethyl triethoxysilane Silane, norbornenylethylmethyldiethoxysilane, norbornenylethyldimethylethoxysilane, (meth)acryloxypropyltrimethoxysilane, (meth)acryloxypropylmethyldimethoxysilane, (meth)acryloxypropyldimethylmethoxysilane, (meth)acryloxypropyltriethoxysilane, (meth)acryloxypropylmethyldiethoxysilane, (meth)acryloxypropyldimethylethoxysilane, (meth)acryloxytrimethoxysilane, (meth)acryloxymethylmethyl dimethoxysilane, (meth)acryloxymethyldimethylmethoxysilane, (meth)acryloxymethyltriethoxysilane, (meth)acryloxymethylmethyldiethoxysilane, (meth)acryloxymethyldimethylethoxysilane, (meth)acryloxyoctyltrimethoxysilane, (meth)acryloxyoctylmethyldimethoxysilane, (meth)acryloxyoctyldimethylmethoxysilane, (meth)acryloxyoctyltriethoxysilane, (meth)acryloxyoctylmethyldiethoxysilane, andAn elastomer composition having a silicon-containing functional group introduced therein by at least one functional compound selected from the group consisting of (meth)acryloxyoctyldimethylethoxysilane. (i) If Ash+BC>PC, then Ash+BC-PC≦AE (ii) If Ash+BC≦PC, then AE+Ash≦PC and BC≦AE

2. The silica has a nitrogen adsorption specific surface area of ​​180 m ２ 2. The elastomer composition of claim 1, comprising at least 1 / g of silica.

3. The elastomer composition according to claim 1 or 2, wherein the AE is less than 20% by mass.

4. 4. The elastomer composition according to claim 1, wherein the elastomer component comprises two or more kinds of elastomer components, at least one of which is an isoprene-based rubber or a butadiene rubber.

5. 5. The elastomer composition according to claim 1, wherein the content of the styrene-butadiene rubber in 100% by mass of the elastomer component is 10 to 90% by mass.

6. 6. The elastomer composition according to claim 1, wherein the content of the functionalized resin is 3 to 35 parts by mass per 100 parts by mass of the elastomer component.

7. (i) When Ash+BC>PC, the content of oil is 10 to 90 parts by mass per 100 parts by mass of the elastomer component, (ii) When Ash + BC ≦ PC, ​​the content of oil per 100 parts by mass of the elastomer component is 20 parts by mass or less. The elastomer composition according to any one of claims 1 to 6.

8. A tire having a rubber layer 1 made of the elastomer composition according to any one of claims 1 to 7 and a rubber layer 2 adjacent to the rubber layer 1 on the inner side in the tire radial direction, The tire, wherein a difference in acetone extractables (AE) between the first rubber layer and the second rubber layer is within 10% by mass.

9. 9. The tire of claim 8, wherein the tread has a negative ratio of 50% or less.

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