Rubber composition and tire

Abstract

The purpose of the present invention is to provide a rubber composition having an excellent low-exothermic property. Provided is a rubber composition which comprises a diene rubber component, at least one compound selected from the group consisting of a compound represented by formula (1) and a compound represented by formula (2), and a filler.

Description

[Technical Field]

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

[0002] In recent years, as carbon dioxide emission regulations have become stricter worldwide, there has been a growing demand for improved fuel efficiency in automobiles. One solution to this is to reduce the rolling resistance of tires and improve fuel efficiency.

[0003] Patent Document 1 discloses a rubber composition obtained by blending a rubber component made of at least one rubber selected from the group consisting of natural rubber and synthetic rubber, and at least one selected from the group consisting of hydrazide compounds.

[0004] Patent Document 2 discloses a pneumatic tire formed from a rubber composition containing a rubber component consisting of at least one rubber selected from natural rubber and diene-based synthetic rubber, carbon black, and a hydrazide-based compound.

[0005] In conventional technology, low heat buildup and processability (Mooney viscosity) are generally in a trade-off relationship, making it difficult to improve both properties in a balanced manner. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 98 / 044040 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-191720 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a rubber composition having excellent low heat buildup properties. [Means for solving the problem]

[0008] As a result of extensive research conducted by the present inventors to achieve the above object, it has been discovered that by using a specific compound and filler, it is possible to provide a rubber composition that exhibits excellent low heat buildup.

[0009] The present inventors have also found that it is possible to provide a rubber composition that exhibits excellent processability.

[0010] Based on this finding, the present inventors have conducted further research and have completed the present invention.

[0011] That is, the present invention provides the following rubber composition.

[0012] Section 1. A rubber composition comprising: a diene rubber component, at least one compound selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2); filling material A rubber composition comprising:

[0013] [ka]

[0014] [In formula (1), R 1 , and R 2 are the same or different and each represents a hydrogen atom or a hydrocarbon group, and the hydrocarbon group may further have an optional substituent. 1 , and R 2 may be bonded to each other. 3 are the same or different and represent any substituent, and n represents an integer of 0 to 4.

[0015] [ka]

[0016] [In formula (2), R 4are the same or different and represent any substituent, and m represents an integer of 0 to 4.

[0017] Section 2. In the formula (1), R 1 Item 2. The composition according to item 1, wherein is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0018] Section 3. In the formula (1), R 2 3. The composition according to item 1 or 2, wherein is an alkyl group having 1 to 18 carbon atoms.

[0019] Section 4. 4. The composition according to any one of items 1 to 3, wherein n=0 in formula (1).

[0020] Section 5. 5. The composition according to any one of items 1 to 4, wherein m=0 in formula (2).

[0021] Section 6. The filler contains at least silica, 6. The rubber composition according to any one of items 1 to 5, wherein the silica is contained in an amount of 5 parts by mass or more per 100 parts by mass of the diene rubber component.

[0022] Section 7. The diene rubber component contains at least natural rubber, 7. The rubber composition according to any one of items 1 to 6, wherein the natural rubber accounts for 40% by mass or more of 100% by mass of the diene rubber component.

[0023] Section 8. 8. A tire tread or tire sidewall using the rubber composition according to any one of items 1 to 7. [Effects of the Invention]

[0024] The rubber composition of the present invention exhibits excellent low heat buildup.

[0025] The rubber composition of the present invention further exhibits excellent processability. DETAILED DESCRIPTION OF THE INVENTION

[0026] 1. Rubber composition The rubber composition of the present invention contains a diene rubber component, at least one compound selected from the group consisting of compounds represented by formula (1) and compounds represented by formula (2), and a filler.

[0027] A rubber material obtained by using the rubber composition of the present invention exhibits excellent low heat buildup.

[0028] The rubber material obtained by using the rubber composition of the present invention further exhibits excellent processability.

[0029] The rubber material obtained by using the rubber composition of the present invention can be preferably used for tires and the like.

[0030] 1-1. Compound represented by formula (1) The compound represented by formula (1) is represented by the following structural formula:

[0031] [ka]

[0032] [In formula (1), R 1 , and R 2 are the same or different and each represents a hydrogen atom or a hydrocarbon group, and the hydrocarbon group may further have an optional substituent. 1 , and R 2 may be bonded to each other. 3 are the same or different and represent any substituent, and n represents an integer of 0 to 4.

[0033] R 1 , and R 2 are the same or different and each is a hydrogen atom or a hydrocarbon group.

[0034] The hydrocarbon group is preferably an aliphatic hydrocarbon group, an aromatic hydrocarbon group, etc. The aliphatic hydrocarbon group is preferably a saturated hydrocarbon group, an unsaturated hydrocarbon group, etc., and is a linear, branched, cyclic, or other aliphatic hydrocarbon group.

[0035] R 1 , and R 2 are preferably each a hydrogen atom or a linear, branched, or cyclic alkyl group.

[0036] R 1 is an alkyl group, R 1 The number of carbon atoms in the group is preferably 1 to 4, more preferably 1 or 2, and even more preferably 1.

[0037] R 2 is an alkyl group, R 2 The number of carbon atoms is preferably 1 to 18, and more preferably 1 to 11.

[0038] R 1 , and R 2 may optionally be linked to each other to form an alkylene group.

[0039] R 1 , and R 2 The hydrocarbon groups may each optionally have one or more identical or different substituents.

[0040] R 3 are any one or more identical or different substituents.

[0041] n represents an integer of 0 to 4.

[0042] The substituent is not particularly limited and is preferably a halogen atom, an amino group, an aminoalkyl group, an alkoxycarbonyl group, an acyl group, an acyloxy group, an amide group, a carboxyl group, a carboxyalkyl group, a formyl group, a nitrile group, a nitro group, an alkyl group, a hydroxyalkyl group, a hydroxyl group, an alkoxy group, an aryl group, an aryloxy group, a heterocyclic group, a thiol group, an alkylthio group, an arylthio group, or the like.

[0043] The group may have preferably 1 to 4, more preferably 1 to 3, substituents at substitutable positions.

[0044] The amino group is preferably an amino group represented by -NH2.

[0045] The amino group is preferably a linear or branched monoalkylamino group (substituted amino group) having 1 to 6 carbon atoms, such as methylamino, ethylamino, n-propylamino, isopropylamino, n-butylamino, isobutylamino, s-butylamino, t-butylamino, 1-ethylpropylamino, n-pentylamino, neopentylamino, n-hexylamino, isohexylamino, or 3-methylpentylamino.

[0046] The amino group is preferably a dialkylamino group (substituted amino group) having two linear or branched alkyl groups having 1 to 6 carbon atoms, such as a dimethylamino, ethylmethylamino, or diethylamino group.

[0047] Among these substituents, amino and hydroxyl groups are preferred, with hydroxyl groups being more preferred, and the 3-position is particularly preferred as the substitution position.

[0048] The compound represented by formula (1) is preferably N'-(1-methylethylidene)picolinic acid hydrazide, N'-(1,3-dimethylbutylidene)picolinic acid hydrazide, N'-(1,3-dimethylbutylidene)3-hydroxypicolinic acid hydrazide, N'-(1-methyldodecylidene)picolinic acid hydrazide, N'-octylidenepicolinic acid hydrazide, or N'-decylidenepicolinic acid hydrazide. hydrazide, N'-dodecylidenepicolinic acid hydrazide, N'-(1,3-dimethylbutylidene)-4-chloropicolinic acid hydrazide, N'-(1,3-dimethylbutylidene)-4-methoxypicolinic acid hydrazide, N'-(1,3-dimethylbutylidene)-3-methylpicolinic acid hydrazide, N'-(1,3-dimethylbutylidene)-3-hydroxypicolinic acid hydrazide, etc.

[0049] A preferred embodiment of the present invention is a compound in which n=0 in the above formula (1), also from the viewpoint of processability.

[0050] A more preferred compound is N'-(1,3-dimethylbutylidene)picolinic acid hydrazide.

[0051] 1-2. Compound represented by formula (2) The compound represented by formula (2) is represented by the following structural formula:

[0052] [ka]

[0053] [In formula (2), R 4 are the same or different and represent any substituent, and m represents an integer of 0 to 4.

[0054] R 4 are any one or more identical or different substituents.

[0055] m represents an integer of 0 to 4;

[0056] The substituent is not particularly limited and is preferably a halogen atom, an amino group, an aminoalkyl group, an alkoxycarbonyl group, an acyl group, an acyloxy group, an amide group, a carboxyl group, a carboxyalkyl group, a formyl group, a nitrile group, a nitro group, an alkyl group, a hydroxyalkyl group, a hydroxyl group, an alkoxy group, an aryl group, an aryloxy group, a heterocyclic group, a thiol group, an alkylthio group, an arylthio group, or the like.

[0057] The group may have preferably 1 to 4, more preferably 1 to 3, substituents at substitutable positions.

[0058] The amino group is preferably an amino group represented by -NH2.

[0059] The amino group is preferably a linear or branched monoalkylamino group (substituted amino group) having 1 to 6 carbon atoms, such as methylamino, ethylamino, n-propylamino, isopropylamino, n-butylamino, isobutylamino, s-butylamino, t-butylamino, 1-ethylpropylamino, n-pentylamino, neopentylamino, n-hexylamino, isohexylamino, or 3-methylpentylamino.

[0060] The amino group is preferably a dialkylamino group (substituted amino group) having two linear or branched alkyl groups having 1 to 6 carbon atoms, such as a dimethylamino, ethylmethylamino, or diethylamino group.

[0061] Among these substituents, amino and hydroxyl groups are preferred, with hydroxyl groups being more preferred, and the 3-position is particularly preferred as the substitution position.

[0062] The compound represented by formula (2) is preferably picolinic acid hydrazide, 3-hydroxypicolinic acid hydrazide, 4-hydroxypicolinic acid hydrazide, 5-hydroxypicolinic acid hydrazide, 6-hydroxypicolinic acid hydrazide, 3-aminopicolinic acid hydrazide, 4-aminopicolinic acid hydrazide, 5-aminopicolinic acid hydrazide, 6-aminopicolinic acid hydrazide, or the like.

[0063] A preferred embodiment of the present invention is picolinic acid hydrazide (a compound where m=0) in the above formula (2) from the viewpoint of processability as well.

[0064] 1-3. Diene rubber component The rubber composition of the present invention contains a diene rubber component.

[0065] The diene rubber component is preferably natural rubber (NR), synthetic diene rubber, a mixture of natural rubber and synthetic diene rubber, or the like.

[0066] From the viewpoint of improving the durability of the rubber composition, natural rubber is preferably used. The natural rubber is preferably contained in an amount of 40% 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 to 100% by mass, based on 100% by mass of the diene rubber component.

[0067] The natural rubber is preferably natural rubber such as natural rubber latex, technically graded rubber (TSR), smoked sheet (RSS), gutta percha, eucommia-derived natural rubber, guayule-derived natural rubber, Russian dandelion-derived natural rubber, etc. The natural rubber is preferably modified natural rubber such as epoxidized natural rubber, methacrylic acid-modified natural rubber, styrene-modified natural rubber, etc.

[0068] The synthetic diene rubber is preferably styrene-butadiene copolymer rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene-propylene-diene terpolymer rubber (EPDM), styrene-isoprene-styrene triblock copolymer (SIS), styrene-butadiene-styrene triblock copolymer (SBS), or modified synthetic diene rubbers thereof.

[0069] The modified synthetic diene rubber is preferably a diene rubber modified by a modification technique such as main chain modification, one end modification, or both ends modification.

[0070] The modified functional group of the modified synthetic diene rubber is preferably a functional group containing a hetero atom such as an epoxy group, an amino group, an alkoxy group, or a hydroxyl group, and preferably contains one or more of these functional groups.

[0071] There are no particular limitations on the cis / trans / vinyl ratio of the diene moiety, and any ratio is preferred.

[0072] There are no particular limitations on the weight average molecular weight and molecular weight distribution of the diene rubber, but the weight average molecular weight is preferably 150,000 to 1,400,000.

[0073] The method for producing the synthetic diene rubber is not particularly limited, and is preferably a synthesis method such as emulsion polymerization, solution polymerization, radical polymerization, anionic polymerization, or cationic polymerization.

[0074] The synthetic diene rubber is preferably IR, SBR, BR, or a mixture of two or more selected from these, more preferably SBR, BR, or a mixture of two or more selected from these. The synthetic diene rubber is particularly preferably a diene rubber containing a structure obtained by polymerizing 1,3-butadiene.

[0075] The glass transition temperature of the synthetic diene rubber (preferably a diene rubber containing a structure obtained by polymerizing 1,3-butadiene) is preferably in the range of -110°C to -20°C, more preferably in the range of -70°C to -20°C, from the viewpoint of achieving both abrasion resistance and braking characteristics.

[0076] In the rubber composition of the present invention, preferably 10 to 60% by mass, more preferably 50 to 60% by mass, of the diene rubber is a diene rubber having a glass transition point in the range of -110°C to -20°C (more preferably in the range of -70°C to -20°C).

[0077] The compounding ratio of at least one compound selected from the group consisting of the compound represented by formula (1) and the compound represented by formula (2) to the diene rubber component is preferably 0.1 to 50 parts by mass, more preferably 0.1 to 10 parts by mass, still more preferably 0.15 to 5 parts by mass, and particularly preferably 0.2 to 4 parts by mass, per 100 parts by mass of the diene rubber component.

[0078] In a preferred embodiment of the present invention, the diene rubber component contains at least natural rubber, and the rubber composition contains 40% by mass or more of the natural rubber in 100% by mass of the diene rubber component.

[0079] By blending at least one compound selected from the group consisting of the compound represented by formula (1) and the compound represented by formula (2) with respect to the diene rubber component in the above-mentioned ratio, excellent low heat buildup is exhibited. Furthermore, by blending in the above-mentioned ratio, excellent processability is also exhibited.

[0080] 1-4.Filling material The rubber composition of the present invention contains a filler (reinforcing material).

[0081] The filler is preferably a conventional filler used in the rubber industry.

[0082] The filler is preferably an inorganic filler such as silica, carbon black, etc. For the purpose of improving the effect of low heat generation, it is more preferable to use silica as the filler.

[0083] The inorganic filler is preferably an inorganic compound known in the art for use in the rubber industry.

[0084] The inorganic compound is preferably silica or alumina (Al2O3) such as γ-alumina or α-alumina.

[0085] The inorganic compound is preferably alumina monohydrate (Al2O3·H2O) such as boehmite or diaspore.

[0086] The inorganic compound is preferably aluminum hydroxide [Al(OH)3] such as gibbsite or bayerite.

[0087] The inorganic compound is preferably aluminum carbonate [Al2(CO3)3], magnesium hydroxide [Mg(OH)2], magnesium oxide (MgO), magnesium carbonate (MgCO3), talc (3MgO·4SiO2·H2O), attapulgite (5MgO·8SiO2·9H2O), titanium dioxide (TiO2), titanium dioxide (TiO2), titanium dioxide (TiO 2n-1), calcium oxide (CaO), calcium hydroxide [Ca(OH)2], magnesium aluminum oxide (MgO·Al2O3), clay (Al2O3·2SiO2), kaolin (Al2O3·2SiO2·2H2O), pyrophyllite (Al2O3·4SiO2·H2O), bentonite (Al2O3·4SiO2·2H2O), aluminum silicate (Al2SiO5, Al4·3SiO4·5H2O, etc.), magnesium silicate (Mg2SiO4, MgSiO3, etc.) ), calcium silicates (e.g., Ca2·SiO4), calcium aluminum silicates (e.g., Al2O3·CaO·2SiO2), calcium magnesium silicate (CaMgSiO4), calcium carbonate (CaCO3), zirconium oxide (ZrO2), zirconium hydroxide [ZrO(OH)2·nH2O], zirconium carbonate [Zr(CO3)2], and crystalline aluminosilicates containing hydrogen, alkali metals, or alkaline earth metals to compensate for the charge, such as various zeolites.

[0088] In order to improve the affinity with the rubber component, the inorganic filler is preferably one whose surface has been organically treated.

[0089] From the viewpoint of damping characteristics, the inorganic filler is preferably silica.

[0090] The BET specific surface area of ​​the silica is not particularly limited, but is preferably 40 m 2 / g to 350m 2 / g range. Silica having a BET specific surface area in this range has the advantage of being able to provide both rubber reinforcement and dispersibility in the rubber component.

[0091] The BET specific surface area is measured in accordance with ISO 5794-1.

[0092] The BET specific surface area of ​​the silica is preferably in the range of 40 m 2 / g to 350m 2 / g, more preferably 100m 2 / g to 270m 2 / g, and particularly preferably 110m 2 / g to ~270m 2 / g.

[0093] Commercially available silica products include, for example, the product name "HD165MP" (BET specific surface area = 165 m) manufactured by Quechen Silicon Chemical Co., Ltd. 2 / g), "HD115MP" (BET specific surface area = 115m 2 / g), "HD200MP" (BET specific surface area = 200m 2 / g), "HD250MP" (BET specific surface area = 250m 2 / g), and the product name "Nipsil AQ" manufactured by Tosoh Silica Corporation (BET specific surface area = 205 m 2 / g), "Nipsil KQ" (BET specific surface area = 240 m 2 / g), and the product name "Ultrasil VN3" manufactured by Degussa (BET specific surface area = 175 m 2 / g), etc.

[0094] The carbon black is not particularly limited, and examples thereof include commercially available carbon black and carbon-silica dual phase filler.

[0095] The carbon black is preferably a high, medium or low structure SAF, ISAF, IISAF, N110, N134, N220, N234, N330, N339, N375, N550, HAF, FEF, GPF, SRF grade carbon black, or the like.

[0096] The carbon black is preferably a carbon black of the SAF, ISAF, IISAF, N134, N234, N330, N339, N375, HAF, FEF grade.

[0097] The range of DBP absorption of carbon black is not particularly limited, and is preferably within 60 cm 3 / 100g to 200cm 3 / 100g, more preferably 70cm 3 / 100g to 180cm 3 / 100g, and particularly preferably 80cm 3 / 100g to 160cm 3 / 100g.

[0098] The nitrogen adsorption specific surface area (N2SA, measured in accordance with JIS K 6217-2:2001) of the carbon black is preferably in the range of 30 m 2 / g to 200m 2 / g, more preferably 40m 2 / g to 180m 2 / g, and particularly preferably 50m 2 / g to 160m 2 / g.

[0099] The amount of the filler to be compounded is preferably 30 to 120 parts by mass, more preferably 30 to 100 parts by mass, and even more preferably 40 to 90 parts by mass, per 100 parts by mass of the diene rubber component.

[0100] When silica is used as a filler, the amount of silica mixed per 100 parts by mass of the diene rubber component is preferably 5 to 120 parts by mass, more preferably 5 to 100 parts by mass, even more preferably 10 to 90 parts by mass, particularly preferably 10 to 50 parts by mass, and most preferably 10 to 30 parts by mass.

[0101] In a preferred embodiment of the present invention, the filler contains at least silica, and the rubber composition contains 5 parts by mass or more of the silica per 100 parts by mass of the diene rubber component.

[0102] 1-5.Other ingredients In addition to the compound, rubber component, and filler, the rubber composition of the present invention preferably contains compounding agents that are commonly used in the rubber industry.

[0103] The compounding agents are preferably antioxidants, antiozonants, softeners, processing aids, waxes, resins, foaming agents, oils, stearic acid, zinc oxide (ZnO), vulcanization accelerators, vulcanization retarders, vulcanizing agents (sulfur), etc., and are appropriately selected and compounded.

[0104] When silica is used as a filler, a silane coupling agent is preferably compounded for the purposes of enhancing the reinforcing properties of the rubber composition by silica and enhancing the low heat buildup and wear resistance of the rubber composition.

[0105] The silane coupling agent that can be used in combination with silica is not particularly limited, and it is preferable to use a commercially available product.

[0106] The silane coupling agent is preferably a sulfide-based, polysulfide-based, thioester-based, thiol-based, olefin-based, epoxy-based, amino-based, or alkyl-based silane coupling agent.

[0107] The sulfide-based silane coupling agent is preferably bis(3-triethoxysilylpropyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(3-methyldimethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(3-triethoxysilylpropyl)disulfide, bis(3-trimethoxysilylpropyl)disulfide, bis(3-methyldimethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)disulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(3-trimethoxysilylpropyl)trisulfide, bis(3-methyldimethoxysilylpropyl) bis(2-monoethoxydimethylsilylpropyl) trisulfide, bis(2-triethoxysilylethyl) trisulfide, bis(3-monoethoxydimethylsilylpropyl) tetrasulfide, bis(3-monoethoxydimethylsilylpropyl) trisulfide, bis(3-monoethoxydimethylsilylpropyl) disulfide, bis(3-monomethoxydimethylsilylpropyl) tetrasulfide, bis(3-monomethoxydimethylsilylpropyl) trisulfide, bis(3-monomethoxydimethylsilylpropyl) disulfide, bis(2-monoethoxydimethylsilylethyl) tetrasulfide, bis(2-monoethoxydimethylsilylethyl) trisulfide, bis(2-monoethoxydimethylsilylethyl) disulfide, and the like.

[0108] The sulfide-based silane coupling agent is more preferably bis(3-triethoxysilylpropyl)tetrasulfide.

[0109] The thioester-based silane coupling agent is preferably 3-hexanoylthiopropyltriethoxysilane, 3-octanoylthiopropyltriethoxysilane, 3-decanoylthiopropyltriethoxysilane, 3-lauroylthiopropyltriethoxysilane, 2-hexanoylthioethyltriethoxysilane, 2-octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, 2-lauroylthioethyltriethoxysilane, 3-hexanoylthiopropyltrimethoxysilane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, 2-octanoylthioethyltrimethoxysilane, 2-decanoylthioethyltrimethoxysilane, 2-lauroylthioethyltrimethoxysilane, or the like.

[0110] The thiol-based silane coupling agent is preferably 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-[ethoxybis(3,6,9,12,15-pentaoxaoctacosan-1-yloxy)silyl]-1-propanethiol, or the like.

[0111] Preferred examples of the olefin-based silane coupling agent include dimethoxymethylvinylsilane, vinyltrimethoxysilane, dimethylethoxyvinylsilane, diethoxymethylvinylsilane, triethoxyvinylsilane, vinyltris(2-methoxyethoxy)silane, allyltrimethoxysilane, allyltriethoxysilane, p-styryltrimethoxysilane, 3-(dimethoxymethylsilyl)propyl acrylate, 3-(trimethoxysilyl)propyl acrylate, 3-[dimethoxy(methyl)silyl]propyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate, 3-[dimethoxy(methyl)silyl]propyl methacrylate, 3-(triethoxysilyl)propyl methacrylate, and 3-[tris(trimethylsiloxy)silyl]propyl methacrylate.

[0112] Preferred examples of the epoxy-based silane coupling agent include 3-glycidyloxypropyl(dimethoxy)methylsilane, 3-glycidyloxypropyltrimethoxysilane, diethoxy(3-glycidyloxypropyl)methylsilane, triethoxy(3-glycidyloxypropyl)silane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0113] The epoxy-based silane coupling agent is more preferably 3-glycidyloxypropyltrimethoxysilane.

[0114] Preferred amino-based silane coupling agents include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-ethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane.

[0115] The amino-based silane coupling agent is more preferably 3-aminopropyltriethoxysilane.

[0116] Preferred examples of the alkyl silane coupling agent include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, and n-decyltrimethoxysilane.

[0117] The alkyl-based silane coupling agent is more preferably methyltriethoxysilane.

[0118] More preferred silane coupling agents include bis(3-triethoxysilylpropyl)tetrasulfide, bis(3-triethoxysilylpropyl)disulfide, and 3-[ethoxybis(3,6,9,12,15-pentaoxaoctacosan-1-yloxy)silyl]-1-propanethiol.

[0119] The silane coupling agents may be used alone or in combination of two or more.

[0120] The amount of the silane coupling agent to be blended is preferably 2 to 20 parts by mass, and more preferably 3 to 15 parts by mass, per 100 parts by mass of silica.

[0121] By setting the compounding amount of the silane coupling agent to 2 parts by mass or more per 100 parts by mass of silica, the effect of low heat buildup of the rubber composition can be more suitably exhibited, and by setting the compounding amount of the silane coupling agent to 20 parts by mass or less per 100 parts by mass of silica, it is possible to reduce the cost of the rubber composition, improving economic efficiency.

[0122] 2. Tires By manufacturing a tire using the rubber composition of the present invention, it is possible to obtain a tire having excellent mechanical properties, particularly excellent tear strength. The tire of the present invention can be manufactured by a conventional method except for using the rubber composition of the present invention.

[0123] The tires are preferably truck and bus tires, heavy-duty tires, winter tires, and the like.

[0124] In the tire of the present invention, the rubber composition is preferably used in at least one member selected from the tread portion, sidewall portion, bead area portion, belt portion, carcass portion, and shoulder portion.

[0125] In the tire (pneumatic tire) of the present invention, more preferably, components such as the tread portion and sidewall portion are formed from the rubber composition of the present invention.

[0126] The tread portion has a tread pattern and is the outer shell portion of the tire that directly contacts the road surface, protecting the carcass and preventing wear and damage. The tread portion refers to the cap tread that constitutes the tire's contact area and / or the base tread disposed inside the cap tread.

[0127] In the tire of the present invention, the rubber composition is particularly preferably used in the tread portion.

[0128] The sidewall portion is the portion of a pneumatic radial tire extending from the lower side of the shoulder portion to the bead portion. The sidewall portion protects the carcass and is the portion that is most subject to bending during running.

[0129] In the tire of the present invention, the rubber composition is particularly preferably used in the sidewall portion.

[0130] The bead area is the part that secures both ends of the carcass cord and also secures the tire to the rim. The bead is made of bundled high-carbon steel.

[0131] The belt is a reinforcing band stretched circumferentially between the radial tread and carcass, tightening the carcass like a barrel hoop to increase the rigidity of the tread.

[0132] The carcass is a cord layer portion that forms the skeleton of the tire, and serves to withstand the load, impact, and inflation pressure that the tire receives.

[0133] The shoulder portion is the shoulder part of the tire and serves to protect the carcass.

[0134] The tire of the present invention is preferably manufactured according to methods known in the tire art.

[0135] The gas to be filled into the tire is preferably normal air or air with an adjusted oxygen partial pressure, or an inert gas such as nitrogen, argon, or helium.

[0136] A preferred embodiment of the present invention is a tire tread or a tire sidewall using the rubber composition.

[0137] 3.Method for producing rubber composition The method for producing the rubber composition of the present invention is not particularly limited, and preferably involves mixing the compound, a rubber component, a filler, and, if necessary, other components. The compound is produced by a known method.

[0138] The mixing method is not particularly limited, and a known method is preferably used. Preferably, the compound and, if necessary, other components are kneaded using a kneader or the like.

[0139] Although the embodiments of the present invention have been described above, the present invention is not limited to these examples and can be embodied in various forms without departing from the spirit of the present invention. [Example]

[0140] The embodiments of the present invention will be described more specifically based on Production Examples and Examples.

[0141] The present invention is not limited to these.

[0142] Production Example 1: Production of picolinic acid hydrazide (compound a) 9.71 g of hydrazine monohydrate was added to 25.3 g of methyl picolinate and 20 mL of methanol, and the mixture was heated under reflux for 18 hours. After cooling to room temperature, the reaction solution was filtered, and the resulting solid was crushed and washed with 20 mL of isopropyl alcohol and dried under reduced pressure to obtain 22.9 g of the target product (yield 90%).

[0143] Melting point: 100℃ 1H-NMR(500MHz,DMSO-d6,δppm):4.57(s,2H),7.58(m,1H),7.99(m,2H),8.62(m,1H),9.87(s,1H)

[0144] [ka]

[0145] Production Example 2: Production of N'-(1,3-dimethylbutylidene)picolinic acid hydrazide (compound b) 14.6 g of methyl isobutyl ketone was added to 10 g of picolinic acid hydrazide and 20 mL of methanol, and the mixture was heated under reflux for 18 hours. The solvent was removed under reduced pressure, and 20 mL of isopropyl alcohol was added to the resulting residue. The mixture was stirred under ice cooling, resulting in the precipitation of crystals. The crystals were filtered, washed with isopropyl alcohol, and the resulting solid was dried under reduced pressure to obtain 15.6 g of the target product (yield 98%).

[0146] Melting point: 84℃ 1H-NMR(400MHz,DMSO-d6,δppm):0.91-0.96(m,6H),1.97-2.04(m,4H),2.21-2.29( m,2H),7.64-7.67(m,1H),8.03-8.11(m,2H),8.68-8.69(m,1H),10.75-10.85(m,1H)

[0147] [ka]

[0148] Preparation Example 3: Preparation of 3-hydroxypicolinic acid hydrazide (compound c) 2.8 g of concentrated sulfuric acid was added to 5.00 g of 3-hydroxypicolinic acid in 75 mL of methanol and heated under reflux for 36 hours. The solvent was evaporated under reduced pressure, and the resulting residue was adjusted to pH 8 with aqueous potassium carbonate under ice cooling. The product was extracted with dichloromethane, dried over sodium sulfate, and the solvent was evaporated under reduced pressure to obtain 4.36 g of the methyl ester (74% yield).

[0149] To 4.31 g of the resulting methyl ester in 40 mL of methanol, 2.13 g of hydrazine monohydrate was added and the mixture was stirred at 50°C for 18 hours. The solvent was removed by distillation under reduced pressure, and a small amount of methanol was added to the resulting residue and stirred to precipitate crystals. The crystals were filtered and washed with methanol, and the resulting solid was dried under reduced pressure to obtain 3.17 g of the target product (yield 74%).

[0150] Melting point: 143℃ 1H-NMR(400MHz,DMSO-d6,δppm):4.70(br-s,2H),7.38-7.42(m,1H),7.47-7.50(m,1H),8.11-8.13(m,1H),10.61(br-s,1H)

[0151] [ka]

[0152] Production Example 4: Production of N'-(1,3-dimethylbutylidene) 3-hydroxypicolinic acid hydrazide (compound d) 3.10 g of 3-hydroxypicolinic acid hydrazide was added to 40 mL of methanol, and 8.00 g of methyl isobutyl ketone was added and heated under reflux for 18 hours. The solvent was removed under reduced pressure, and 20 mL of hexane was added to the resulting residue and stirred to precipitate crystals. The crystals were filtered, washed with hexane, and the resulting solid was dried under reduced pressure to obtain 5.80 g of the desired product (yield 92%).

[0153] Melting point: 93℃ 1H-NMR(400MHz,DMSO-d6,δppm):0.91-0.94(m,6H),1.96-2.04(m,4H),2.05-2. 26(m,2H),7.46-7.48(m,1H),7.55-7.59(m,1H),8.20-8.21(m,1H),10.92(s,1H)

[0154] [ka]

[0155] Production Example 5: Production of nicotinic acid hydrazide (compound e) 13.7 g of methyl nicotinate and 26 mL of isopropyl alcohol were added to 5.50 g of hydrazine monohydrate and heated under reflux for 18 hours. After cooling to room temperature, the reaction solution was filtered, and the resulting solid was crushed and washed with 20 mL of isopropyl alcohol and dried under reduced pressure to obtain 12.2 g of the target product (yield 88%).

[0156] Melting point: 162°C 1H-NMR(400MHz,DMSO-d6,δppm):4.57(s,2H),7.50(m,1H),8.15(m,1H),8.70(m,1H),8.97(m,1H),9.97(s,1H)

[0157] [ka]

[0158] Production Example 6: Production of N'-(1,3-dimethylbutylidene)nicotinic acid hydrazide (compound f) 14.6 g of methyl isobutyl ketone was added to 10 g of nicotinic acid hydrazide and 100 mL of methanol, and the mixture was heated to reflux for 18 hours. The solvent was removed under reduced pressure, and 50 mL of hexane was added to the resulting residue and stirred. After the supernatant hexane layer was removed, another 50 mL of hexane was added and stirred, resulting in the precipitation of crystals. The crystals were filtered, washed with hexane, and the resulting solid was dried under reduced pressure to obtain 15.3 g of the target product (yield 96%).

[0159] Melting point: 72℃ 1H-NMR(400MHz,DMSO-d6,δppm):0.92(d,6H),1.94(s,3H),1.96-2.00(m,1H), 2.18(d,2H),7.52(dd,1H),8.17(d,1H),8.72(d,1H),8.98(s,1H),10.63(s,1H)

[0160] [ka]

[0161] Production Example 7: Production of N'-(1,3-dimethylbutylidene)isonicotinic acid hydrazide (compound h) 14.6 g of methyl isobutyl ketone was added to 10 g of isonicotinic acid hydrazide and 100 mL of methanol, and the mixture was heated under reflux for 18 hours. The solvent was removed by distillation under reduced pressure, and 100 mL of hexane was added to the resulting residue and stirred to precipitate crystals. The crystals were filtered, washed with hexane, and the resulting solid was dried under reduced pressure to obtain 15.8 g of the target product (yield 97%).

[0162] Melting point: 96℃ 1H-NMR(400MHz,DMSO-d6,δppm):0.82-0.91(m,6H),1.91-2.50(m,6H),7.50-7.74(m,2H),8.63-8.72(m,2H),10.69(s,1H)

[0163] [ka]

[0164] Examples 1 to 8 and Comparative Examples 1 to 12: Production of Rubber Compositions The components shown in step (I) of Table 1 were mixed in the proportions (parts by mass) and kneaded in a Banbury mixer.

[0165] After the mixture was cured until the temperature reached 80°C or less, each component listed in step (II) in Table 1 was added in the respective proportions (parts by mass), and the mixture was kneaded while adjusting the maximum temperature to 110°C or less to produce an unvulcanized rubber composition.

[0166] The resulting unvulcanized rubber composition was heated at 150°C for 25 minutes using a vulcanizing press to obtain each rubber composition.

[0167] [Table 1]

[0168] *1:GUANGKEN RUBBER, TSR-20 *2: Manufactured by Sinopec Qilu Petrochemical Co., Ltd., product name "BR9000" *3: Isonicotine, manufactured by Tokyo Chemical Industry Co., Ltd. Acid Drazide *4: Isophthalic acid dihydrazide, manufactured by Otsuka Chemical Co., Ltd. *5: Manufactured by Quechen Silicon Chemical Co., Ltd., product name "HD165MP" *6: Evonik, product name "Si69" (Bis(3-triethoxysilylpropyl)tetrasulfide) *7: Carbon black, manufactured by Tokai Carbon Co., Ltd., Seast 7HM *8: Product name "Nocrac 6C" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. *9: Manufactured by Rhein Chemie Rheinau, product name "Antilux 111" *10: Manufactured by Sichuan Tianyu Grease Co., Ltd. *11: Made by Dalian Zinc Oxide Co., Ltd. *12: Product name "Noccela CZ-G" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. *13: Manufactured by Shanghai Jinghai Chemical Co., Ltd.

[0169] Low heat generation (Tan δ index) test For the rubber compositions of each Example and Comparative Example, the tan δ value was measured using a viscoelasticity measuring device (manufactured by Metravib) at a temperature of 25°C, a dynamic strain of 5%, and a frequency of 15 Hz. For comparison, rubber compositions (Comparative Examples 1, 7, and 10) were prepared using the same formulation and manufacturing method as each Example, except that no compound was added. The tan δ value was expressed as an index of 100, and the low heat buildup index was calculated according to the following formula.

[0170] The smaller the low heat buildup index value, the lower the heat buildup and the smaller the hysteresis loss.

[0171] Formula: Low heat index = (Tan δ value of each of the rubber compositions of Examples 1 to 4 and Comparative Examples 2 to 6) × 100 / (Tan δ value of Comparative Example 1) Formula: Low heat index = (Tan δ values ​​of the rubber compositions of Examples 5 and 6 and Comparative Examples 8 and 9) × 100 / (Tan δ value of Comparative Example 7) Formula: Low heat index = (Tan δ values ​​of the rubber compositions of Examples 7 and 8 and Comparative Examples 11 and 12) × 100 / (Tan δ value of Comparative Example 10)

[0172] The results are shown in Table 2.

[0173] [Table 2]

[0174] Mooney viscosity measurement (processability) Measurements were made in accordance with JIS K6300-1 (Method for determining viscosity and scorch time using a Mooney viscometer; ML1+4, 100°C). For comparison, a rubber composition (Comparative Example 1) was prepared using the same formulation and manufacturing method as in each Example, except that no compound was added. The Mooney viscosity value was expressed as an index of 100, and the processability index was calculated according to the following formula.

[0175] The smaller the value of the workability index, the better the workability.

[0176] Formula: Processability index = (Mooney viscosity value of the rubber compositions of Examples 1 and 2 and Comparative Example 6) × 100 / (Mooney viscosity value of Comparative Example 1)

[0177] The results are shown in Table 3.

[0178] [Table 3] [Industrial Applicability]

[0179] The rubber composition of the present invention is a rubber composition prepared by adding at least one compound selected from the group consisting of the compounds represented by formula (1) and the compounds represented by formula (2) and a filler to a rubber component to prepare a rubber material. Therefore, the rubber composition exhibits excellent low heat buildup despite containing an additive of at least one compound selected from the group consisting of the compounds represented by formula (1) and the compounds represented by formula (2).

[0180] The rubber composition of the present invention further exhibits excellent processability.

[0181] The rubber composition of the present invention can be suitably used as a material for tires, particularly tire treads or tire sidewalls.

Claims

1. A rubber composition comprising: Diene rubber component, A compound represented by the following formula (2), and filling material Including, The rubber composition comprises 0.1 to 50 parts by mass of a compound represented by the following formula (2) relative to 100 parts by mass of the diene rubber component: 【Chemistry 1】 [In formula (2), R 4 are the same or different and each represents an amino group or a hydroxyl group, and m represents an integer of 0 to 4.

2. The rubber composition according to claim 1, wherein m=0 in the formula (2).

3. The filler contains at least silica, 2. The rubber composition according to claim 1, wherein the silica is contained in an amount of 5 parts by mass or more per 100 parts by mass of the diene rubber component.

4. The diene rubber component contains at least natural rubber, 2. The rubber composition according to claim 1, wherein the natural rubber accounts for 40% by mass or more of 100% by mass of the diene rubber component.

5. A tire tread or tire sidewall using the rubber composition according to any one of claims 1 to 4.

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