JP2019052227A - Rubber composition and tire - Google Patents

Abstract

To provide a rubber composition and tire having excellent wear resistance and wet braking performance.SOLUTION: Blending a rubber component with hydrous titanium oxide and silica with a BET specific surface of 100-210 m/g provides a rubber composition having excellent wear resistance and wet braking performance.SELECTED DRAWING: None

Description

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

  In tires, it is required to improve wear resistance for extending the life and to improve wet braking performance (grip performance on wet road surfaces) to ensure safety.

  For example, in order to improve wet braking performance and wear resistance of a tire, a rubber component is blended with magnesium oxide, aluminum hydroxide, and a specific resin (Patent Document 1), or a specific organosilicon compound is blended (patent) Document 2) has been carried out.

  However, blending a rubber component with magnesium oxide, aluminum hydroxide, and a specific resin, or blending a specific organosilicon compound, the wet braking performance and wear resistance of the tire have not been sufficient.

Japanese Patent Laying-Open No. 2015-227423 JP 2010-260840 A

  An object of the present invention is to provide a rubber composition excellent in wear resistance and wet braking properties.

  Another object of the present invention is to provide a tire excellent in wear resistance and wet braking performance.

  As a result of intensive studies to solve the above problems, the present inventor has found that the above problems can be solved by blending the rubber component with hydrous titanium oxide and specific silica. As a result of further investigation based on this knowledge, the present inventor has completed the present invention.

The present invention provides the following rubber composition and tire.
Item 1.
A rubber composition in which hydrous titanium oxide and silica having a BET specific surface area of 100 to 210 m ² / g are blended with a rubber component.
Item 2.
Item 2. The rubber composition according to Item 1, wherein 80 parts by mass or more of diene rubber is contained in 100 parts by mass of the rubber component.
Item 3.
Item 3. The rubber composition according to Item 1 or 2, wherein the diene rubber is at least one selected from the group consisting of natural rubber, isoprene rubber, styrene-butadiene copolymer rubber, and butadiene rubber.
Item 4.
Item 4. The rubber composition according to any one of Items 1 to 3, comprising 1 to 80 parts by mass of hydrous titanium oxide and 20 to 150 parts by mass of silica with respect to 100 parts by mass of the rubber component.
Item 5.
Item 5. The rubber composition according to any one of Items 1 to 4, which is used for a tread portion of a tire.
Item 6.
Item 6. A tire produced using the rubber composition according to any one of Items 1 to 5.

In the present invention, excellent abrasion resistance and excellent wet braking properties can be exhibited by blending a rubber component with hydrous titanium oxide and silica having a BET specific surface area of 100 to 210 m ² / g.

  The present invention is described in detail below.

1. Rubber composition The rubber composition of the present invention contains a rubber component, hydrous titanium oxide and specific silica.

Rubber component In the present specification, the rubber component is not particularly limited. For example, natural rubber (NR), synthetic diene rubber, diene rubber such as a mixture of natural rubber and synthetic diene rubber, and others Non-diene rubbers.

  In addition to natural rubber such as natural rubber latex, technical grade rubber (TSR), smoked sheet (RSS), gutta-percha, Tochu-derived natural rubber, guayule-derived natural rubber, Russian dandelion-derived natural rubber, and epoxidation Examples include natural rubber, modified natural rubber such as methacrylic acid-modified natural rubber, and styrene-modified natural rubber.

  Synthetic diene rubbers include styrene-butadiene copolymer rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene-propylene-diene ternary copolymer Examples thereof include polymer rubber (EPDM), styrene-isoprene-styrene ternary block copolymer (SIS), styrene-butadiene-styrene ternary block copolymer (SBS), and modified synthetic diene rubbers thereof. Examples of the modified synthetic diene rubber include diene rubbers by a modification method such as main chain modification, one-end modification, and both-end modification. Here, the modified functional group of the modified synthetic diene rubber includes one or more functional groups containing heteroatoms such as an epoxy group, an amino group, an alkoxy group, a hydroxyl group, an alkoxysilyl group, a polyether group, and a carboxyl group. Things. Moreover, there is no restriction | limiting in particular about the ratio of cis / trans / vinyl of a diene part, It can use suitably in any ratio. The number average molecular weight and molecular weight distribution of the diene rubber are not particularly limited, and a diene rubber having a number average molecular weight of 500 to 3 million and a molecular weight distribution of 1.5 to 15 can be suitably used. Moreover, there is no restriction | limiting in particular also about the manufacturing method of synthetic diene rubber, What was synthesize | combined by emulsion polymerization, solution polymerization, radical polymerization, anionic polymerization, cationic polymerization etc. is mentioned.

  Known non-diene rubbers can be widely used.

  The rubber component preferably contains a diene rubber, more preferably 80 parts by mass or more of diene rubber in 100 parts by mass of the rubber component, and is blended at a ratio of 80 to 100 parts by mass. Particularly preferred.

  The glass transition point of the diene rubber is not particularly limited.

  A rubber component can be used individually by 1 type or in mixture (blend) of 2 or more types. Among these, preferable rubber components are natural rubber, IR, SBR, BR, or a mixture of two or more selected from these, more preferably natural rubber, SBR, BR, or two or more selected from these. It is a mixture. Moreover, although there is no restriction | limiting in particular in these blend ratios, It is preferable to mix | blend SBR, BR, or these mixtures in the ratio of 50-100 mass parts in 100 mass parts of rubber components, and 75-100 mass parts is sufficient. It is more preferable to mix. When blending a mixture of SBR and BR, the total amount of SBR and BR is preferably in the above range. Moreover, SBR at this time is 50-100 mass parts, and it is preferable that BR is the range of 0-50 mass parts.

Hydrous titanium oxide In the present specification, hydrous titanium oxide means “titanium oxide hydrate”, “metatitanic acid”, “β-titanic acid”, “titanium hydroxide”, “orthotitanic acid”, “α-titanic acid”. And the molecular formula is represented by TiO (OH) ₂ , TiO ₂ .H ₂ O, Ti (OH) ₄ , TiO ₂ .2H ₂ O, etc., and sulfuric acid. It is known as a hydrolyzate of water-soluble titanium compounds such as titanium and titanium chloride. Hydroxylated titanium has a peak pattern similar to anatase-type titanium oxide in X-ray diffraction, but unlike titanium oxide, it is a low crystalline compound. In this specification, “low crystallinity” is different from the case of amorphous in X-ray diffraction, although the presence of a peak can be confirmed, but the peak width is different from a steep peak as shown by a crystalline compound. That is, having an intermediate peak between an amorphous and a crystalline compound. The intermediate peak refers to a peak having a half-value width of 0.1 ° or more corresponding to the crystal plane of titanium oxide in the range of 2θ = 20 ° to 30 °. In addition, when a some peak exists in the range of 2 (theta) = 20 degrees-30 degrees, the half value width of a maximum peak is 0.1 degree or more. The full width at half maximum is preferably 0.1 ° to 2 °, more preferably 0.45 ° to 1.8 °. By adjusting the full width at half maximum in such a range, it is possible to obtain a rubber composition having even better wet braking properties. In the present specification, the “half-value width” means the width on the 2θ axis at a half of the peak intensity obtained by X-ray diffraction.

The shape of the hydrous titanium oxide is not particularly limited, and is a plate shape, a spherical shape, a needle shape, or an indefinite shape, and among them, a plate shape, a spherical shape, or an indefinite shape is preferable. The average particle diameter of the hydrous titanium oxide is not particularly limited, but is preferably 10 μm or less, more preferably 0.001 to 10 μm, and still more preferably 0.01 to 5 μm. When the average particle diameter is within the above range, aggregation is unlikely to occur, the processability is excellent, and the fracture resistance of the rubber can be improved. The specific surface area (BET method) of the hydrous titanium oxide is usually 5 to 1000 m ² / g, preferably 10 to 500 m ² / g, more preferably 30 to 200 m ² / g, and still more preferably. 50-150 m ² / g. By adjusting the specific surface area to such a range, it is possible to better disperse in the rubber component, and to obtain a rubber composition having further excellent wet braking properties and excellent wear resistance. it can.

  The hydrous titanium oxide used in the present invention may remove impurities contained in the substance using an acid or an alkali. For example, in the case of hydrous titanium oxide produced from hydrolysis of titanium sulfate, the hydrous titanium oxide contains a large amount of sulfuric acid as an impurity, and when added to rubber as it is, deterioration of the rubber component or deterioration of equipment used. There is a risk. Therefore, hydrous titanium oxide containing sulfuric acid is dispersed in water, and pH is adjusted by adding alkali such as sodium hydroxide, potassium hydroxide and ammonia so that the pH value is 2 to 11, preferably 4 to 8. By doing so, it is possible to prevent deterioration of the rubber component and the equipment used due to an excessive sulfuric acid component. After pH adjustment, the sulfuric acid content is preferably washed and the solid content is preferably filtered, dried, fired, and sieved before use.

  The pH value of the aqueous dispersion of hydrous titanium oxide finally obtained is preferably 2 to 11, more preferably 4 to 8.

  Hydrous titanium oxide may be formed with a treatment layer made of a surface treatment agent on the surface of the hydrous titanium oxide for the purpose of improving dispersibility and improving adhesion to the rubber component. In forming the treatment layer on the surface of the hydrous titanium oxide, the treatment layer can be formed by using 0.1 to 20 parts by mass of a conventionally known surface treatment agent with respect to 100 parts by mass of the hydrous titanium oxide. . As a method for forming the treatment layer, a conventionally known method may be applied. For example, the surface treatment agent is dissolved in a solvent (for example, water, alcohol or a mixed solvent thereof) that promotes hydrolysis, A wet method in which the solution is sprayed onto the hydrous titanium oxide, a method in which a hydrous titanium and a surface treatment agent are blended with the rubber component, and a treatment layer composed of the surface treatment agent is formed on the surface of the hydrous titanium oxide can be used. .

  As a compounding quantity of hydrous titanium oxide, it is 1-80 mass parts normally with respect to 100 mass parts of rubber components, Preferably it is 4-60 mass parts, More preferably, it is 10-40 mass parts.

Silica In the present invention, silica having a BET specific surface area of 100 to 210 m ² / g is used from the viewpoint of wear resistance and wet braking properties. The BET specific surface area is measured according to ISO 5794/1.

  In the present invention, any commercially available product can be used as long as the BET specific surface area is the above value. Among these, preferable silica is wet silica, dry silica, or colloidal silica, and more preferably wet silica. In order to improve the affinity of the silica with the rubber component, the surface of the inorganic filler may be organically treated.

In the present invention, preferred silica is silica having a BET specific surface area in the range of 100 to 210 m ² / g, and more preferred is silica having a BET specific surface area in the range of 120 to 190 m ² / g.

Commercially available products of such silica include Quenchen Silicon Chemical Co. , Ltd., Ltd. Product names “HD165MP” (BET specific surface area = 165 m ² / g), “HD115MP” (BET specific surface area = 115 m ² / g), “HD200MP” (BET specific surface area = 200 m ² / g), Tosoh Silica The product name “Nip seal AQ” (BET specific surface area = 205 m ² / g) manufactured by Co., Ltd., the product name “Ultrazil VN3” (BET specific surface area = 175 m ² / g) manufactured by Degussa, and the like can be mentioned.

  In the rubber composition of the present invention, in order to realize better braking characteristics and wear resistance, the amount of silica is usually 20 to 150 parts by mass, preferably 25, per 100 parts by mass of the rubber component. It is -100 mass parts, More preferably, it is 30-90 mass parts.

  In addition to the rubber component, hydrous titanium oxide and silica, various additives shown below can be blended in the rubber composition of the present invention.

The inorganic filler is not particularly limited as long as it is an inorganic compound usually used in the rubber industry. Examples of the inorganic compound that can be used include alumina (Al ₂ O ₃ ) such as γ-alumina and α-alumina; alumina monohydrate (Al ₂ O ₃ .H ₂ O) such as boehmite and diaspore; Aluminum hydroxide [Al (OH) ₃ ] such as Wright; aluminum carbonate [Al ₂ (CO ₃ ) ₃ ], magnesium hydroxide [Mg (OH) ₂ ], magnesium oxide (MgO), magnesium carbonate (MgCO ₃ ), talc _{(3MgO · 4SiO 2 · H 2} O), attapulgite _{(5MgO · 8SiO 2 · 9H 2} O), titanium white _(TiO 2), titanium black _{(TiO 2n-1),} calcium oxide (CaO), calcium hydroxide [ Ca _(OH) 2], magnesium aluminum oxide _{(MgO · Al 2 O 3)} , clay _(Al 2 _{O 3} · SiO _2), kaolin _{(Al 2 O 3 · 2SiO 2} · 2H 2 O), pyrophyllite _{(Al 2 O 3 · 4SiO 2} · H 2 O), bentonite _{(Al 2 O 3 · 4SiO 2} · 2H 2 O) Aluminum silicate (Al ₂ SiO ₅ , Al ₄ · 3SiO ₄ · 5H ₂ O etc.), magnesium silicate (Mg ₂ SiO ₄ , MgSiO ₃ etc.), calcium silicate (Ca ₂ · SiO ₄ etc.), silicic acid Aluminum calcium (Al ₂ O ₃ · CaO · 2SiO ₂ etc.), magnesium calcium silicate (CaMgSiO ₄ ), calcium carbonate (CaCO ₃ ), zirconium oxide (ZrO ₂ ), zirconium hydroxide [ZrO (OH) ₂ · nH ₂ O], zirconium carbonate _{[Zr (CO 3) 2]} , hydrogen to correct electric charge as various zeolites, Alkali metal or crystalline aluminosilicates such as containing an alkaline earth metal. In order to improve the affinity of the inorganic filler with the rubber component, the surface of the inorganic filler may be organically treated.

  The compounding quantity of an inorganic filler is 5-60 mass parts normally with respect to 100 mass parts of rubber components, Preferably it is 7.5-30 mass parts, More preferably, it is 10-20 mass parts.

There is no restriction | limiting in particular as carbon black carbon black, For example, commercially available carbon black, Carbon-Silica Dual phase filler, etc. are mentioned.

  Specifically, as the carbon black, for example, high, medium or low structure SAF, ISAF, IISAF, N110, N134, N220, N234, N330, N339, N375, N550, HAF, FEF, GPF, SRF grade carbon Black etc. are mentioned. Among them, preferable carbon black is SAF, ISAF, IISAF, N134, N234, N330, N339, N375, HAF, or FEF grade carbon black.

There is no restriction | limiting in particular as DBP absorption amount of carbon black, Preferably it is 60-200 cm < ³ > / 100g, More preferably, it is 70-180 cm < ³ > / 100g, Most preferably, it is 80-160 cm < ³ > / 100g.

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

  The compounding quantity of carbon black is 2-80 mass parts normally with respect to 100 mass parts of rubber components, Preferably it is 4-40 mass parts, More preferably, it is 6-30 mass parts.

Other compounding agents are other compounding agents commonly used in the rubber industry, such as anti-aging agents, ozone inhibitors, softeners, processing aids, waxes, resins, foaming agents, oils, stearic acid. Zinc white (ZnO), a vulcanization accelerator, a vulcanization retarder, a vulcanizing agent (sulfur), and the like can be appropriately selected and blended within a range that does not impair the object of the present invention. As these compounding agents, commercially available products can be suitably used.

  Moreover, you may mix | blend a silane coupling agent in order to improve the reinforcement of the rubber composition by a silica, or the purpose of improving the abrasion resistance of a rubber composition.

  It does not restrict | limit especially as a silane coupling agent, A commercial item can be used conveniently. Examples of such silane coupling agents include sulfide-based, polysulfide-based, thioester-based, thiol-based, olefin-based, epoxy-based, amino-based, and alkyl-based silane coupling agents.

  Examples of sulfide-based silane coupling agents include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (3-methyldimethoxysilylpropyl) tetrasulfide, and bis ( 2-triethoxysilylethyl) tetrasulfide, bis (3-triethoxysilylpropyl) disulfide, bis (3-trimethoxysilylpropyl) disulfide, bis (3-methyldimethoxysilylpropyl) disulfide, bis (2-triethoxysilyl) Ethyl) disulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-trimethoxysilylpropyl) trisulfide, bis (3-methyldimethoxysilylpropyl) trisulfide, bis (2-to Ethoxysilylethyl) trisulfide, bis (3-monoethoxydimethylsilylpropyl) tetrasulfide, bis (3-monoethoxydimethylsilylpropyl) trisulfide, bis (3-monoethoxydimethylsilylpropyl) disulfide, bis (3-mono Methoxydimethylsilylpropyl) tetrasulfide, bis (3-monomethoxydimethylsilylpropyl) trisulfide, bis (3-monomethoxydimethylsilylpropyl) disulfide, bis (2-monoethoxydimethylsilylethyl) tetrasulfide, bis (2- Monoethoxydimethylsilylethyl) trisulfide, bis (2-monoethoxydimethylsilylethyl) disulfide and the like. Of these, bis (3-triethoxysilylpropyl) tetrasulfide is particularly preferred.

  Examples of thioester-based silane coupling agents include 3-hexanoylthiopropyltriethoxysilane, 3-octanoylthiopropyltriethoxysilane, 3-decanoylthiopropyltriethoxysilane, and 3-lauroylthiopropyltriethoxysilane. 2-hexanoylthioethyltriethoxysilane, 2-octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, 2-lauroylthioethyltriethoxysilane, 3-hexanoylthiopropyltrimethoxysilane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, 2-octa Ylthio ethyltrimethoxysilane, 2- deca Neu thio ethyltrimethoxysilane, and 2-lauroyl thio ethyl trimethoxysilane.

  Examples of the thiol-based silane coupling agent include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropylmethyldimethoxysilane.

  Examples of olefin-based silane coupling agents include dimethoxymethylvinylsilane, vinyltrimethoxysilane, dimethylethoxyvinylsilane, diethoxymethylvinylsilane, triethoxyvinylsilane, vinyltris (2-methoxyethoxy) silane, allyltrimethoxysilane, allyltri Ethoxysilane, p-styryltrimethoxysilane, 3- (methoxydimethoxydimethylsilyl) 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, 3- [tris (tri Chirushirokishi) silyl] propyl methacrylate, and the like.

  Examples of epoxy-based silane coupling agents include 3-glycidyloxypropyl (dimethoxy) methylsilane, 3-glycidyloxypropyltrimethoxysilane, diethoxy (3-glycidyloxypropyl) methylsilane, and triethoxy (3-glycidyloxypropyl) silane. 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like. Of these, 3-glycidyloxypropyltrimethoxysilane is preferred.

  Examples of amino silane coupling agents include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, and 3-aminopropyl. Trimethoxysilane, 3-aminopropyltriethoxysilane, 3-ethoxysilyl-N- (1,3-dimethylbutylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl)- Examples include 2-aminoethyl-3-aminopropyltrimethoxysilane. Of these, 3-aminopropyltriethoxysilane is preferred.

  Examples of alkyl-based silane coupling agents include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, and isobutyltriethoxy. Examples include silane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, and n-decyltrimethoxysilane. Of these, methyltriethoxysilane is preferred.

  In this invention, a silane coupling agent may be used individually by 1 type, and may be used in combination of 2 or more type.

  0.5-20 mass parts is preferable with respect to 100 mass parts of silica, and, as for the compounding quantity of the silane coupling agent of the rubber composition of this invention, it is especially preferable that it is 2-10 mass parts.

Use of rubber composition The use of the rubber composition of the present invention includes tire treads.

2. Production method of rubber composition The production method of the rubber composition of the present invention is not particularly limited. The method for producing a rubber composition of the present invention includes, for example, a step (A) of kneading a raw material component containing a rubber component, hydrous titanium oxide, specific silica, and, if necessary, an inorganic filler carbon black, and the step (A ) And the step (B) of kneading the vulcanizing agent.

Step (A)
Step (A) is a step of kneading a rubber component, hydrous titanium oxide, specific silica, and, if necessary, a raw material component containing an inorganic filler and carbon black, and is a step before blending a vulcanizing agent. Means. In the step (A), the above-mentioned other compounding agents and the like can be further blended as necessary.

  Examples of the kneading method in the step (A) include a method of kneading a composition containing a rubber component and hydrous titanium oxide, silica, an inorganic filler, carbon black and the like. In this kneading method, the entire amount of each component may be kneaded at a time, or each component may be dividedly added and kneaded according to the purpose such as viscosity adjustment. Further, after kneading the rubber component and the inorganic filler and / or carbon black, the hydrous titanium oxide and silica are added and kneaded, or after kneading the rubber component, the hydrous titanium oxide and silica, the inorganic filler and Alternatively, carbon black may be added and kneaded. Step (A) may be repeatedly kneaded a plurality of times. When adding hydrous titanium oxide, it may be performed simultaneously with the inorganic filler and / or carbon black.

  There is no restriction | limiting in particular as temperature at the time of mixing the rubber composition in a process (A), For example, it is preferable that the upper limit of the temperature of a rubber composition is 120-190 degreeC, and it is 130-175 degreeC. More preferably, it is 140-170 degreeC.

  The mixing time in step (A) is not particularly limited, and is preferably, for example, 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and further preferably 2 minutes to 7 minutes. preferable.

Process (B)
Step (B) is a step (B) in which the mixture obtained in step (A) and the vulcanizing agent are mixed, and means the final stage of kneading.

  In the step (B), a vulcanization accelerator or the like can be further blended as necessary.

  Step (B) can be performed under heating conditions. There is no restriction | limiting in particular as heating temperature of this process, For example, it is preferable that it is 60-140 degreeC, It is more preferable that it is 80-120 degreeC, It is further more preferable that it is 90-120 degreeC.

  The mixing (or kneading) time is not particularly limited, and is preferably, for example, 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and further preferably 60 seconds to 5 minutes. .

  When proceeding from step (A) to step (B), it is preferable to proceed to the next step (B) after lowering the temperature after completion of the previous step by 30 ° C. or more.

  In the method for producing a rubber composition of the present invention, various compounding agents such as a vulcanization accelerator such as stearic acid and zinc white, an anti-aging agent, etc., which are usually compounded in the rubber composition, are optionally added to the step (A Or in step (B).

  For the kneading and mixing in the step (A) and the step (B), a Banbury mixer, a roll, an intensive mixer, a kneader, a twin screw extruder, or the like can be used.

3. Tire The tire of the present invention is a tire produced using the rubber composition of the present invention.

  Examples of the tire of the present invention include tires such as pneumatic tires (radial tires, bias tires, etc.) and solid tires.

  There is no restriction | limiting in particular as a use of a tire, For example, the tire for passenger cars, the tire for heavy loads, the tire for motorcycles (motorcycle), a studless tire, etc. are mentioned, Especially, it can use suitably for a tire for passenger cars.

  There is no restriction | limiting in particular as a shape of a tire of this invention, a structure, a magnitude | size, and a material, According to the objective, it can select suitably.

  In the tire of the present invention, in order to exhibit excellent wear resistance and braking characteristics, it is particularly preferable to use a tire tread manufactured using the composition of the present invention as a constituent member.

  A tire tread is a portion of a tire that has a tread pattern and is in direct contact with the road surface, and protects the carcass and prevents wear and damage. The tire tread is a cap tread and / or a cap tread that constitutes a ground contact portion of the tire. A base tread arranged inside.

  The tire of the present invention can be produced according to a method known so far in the field of tires.

  Moreover, as gas with which a tire is filled, normal or adjusted oxygen partial pressure air; an inert gas such as nitrogen, argon, or helium can be used.

  Hereinafter, the present invention will be specifically described with reference to production examples and examples. However, the examples are merely examples, and the present invention is not limited to the examples.

Production Example 1: Production of hydrous titanium oxide A 100 g of hydrous titanium oxide A ′ (average particle size 3 μm) obtained in the production process of sulfuric acid method titanium oxide was dispersed in 10 L of deionized water to obtain a dispersion. A 48 mass% potassium hydroxide aqueous solution was added to the obtained dispersion so that the pH of the dispersion was 7, and the mixture was stirred. After stirring, the solid was collected by filtration, dried and sieved, and calcined at 500 ° C. for 6 hours to obtain hydrous titanium oxide A.

Production Example 2: Production of hydrous titanium oxide B 100 g of hydrous titanium oxide B ′ (average particle size 1 μm) obtained in the production process of sulfuric acid method titanium oxide was dispersed in 10 L of deionized water to obtain a dispersion. A 48 mass% potassium hydroxide aqueous solution was added to the obtained dispersion so that the pH of the dispersion was 7, and the mixture was stirred. After stirring, the solid was collected by filtration, dried and sieved, and calcined at 500 ° C. for 6 hours to obtain hydrous titanium oxide B.

[Explanation of symbols in the table]
The raw materials used in the examples (in the table) are shown below.
* 1: Styrene-butadiene copolymer rubber (SBR), manufactured by Asahi Kasei Corporation, trade name “Toughden 2000R”
* 2: Butadiene rubber (BR), manufactured by Ube Industries, Ltd., trade name “BR150B”
* 3: Silica, manufactured by Tosoh Silica Co., Ltd., trade name “Nip Seal AQ” (BET specific surface area: 205 m ² / g)
* 4: Silica, manufactured by Solvay, trade name “Z1085Gr” (BET specific surface area: 90 m ² / g)
* 5: Silica, Quechen Silicon Chemical Co. , Ltd., Ltd. Product name “HD250MP” (BET specific surface area: 250 m ² / g)
* 6: Silane coupling agent, manufactured by Evonik Industries AG, trade name “Si75”
* 7: Carbon black, manufactured by Tokai Carbon Co., Ltd., trade name “SEAST 3”
* 8: Anti-aging agent, manufactured by Kawaguchi Chemical Co., Ltd., trade name “Antage 6C”
* 9: Zinc flower (zinc oxide), manufactured by Sakai Chemical Industry Co., Ltd.
* 10: Stearic acid, Sichuan Tianyu Grease Chemical Co. , Ltd., Ltd. * 11: Processing aid, manufactured by Straktor, trade name “HT254”
* 12: Process oil, manufactured by Japan Energy, trade name “X-140” (Aroma oil)
* 13: Sulfur, manufactured by Hosoi Chemical Co., Ltd., trade name “HK200-5”
* 14: Vulcanization accelerator, manufactured by Ouchi Shinsei Chemical Co., Ltd., trade name “NOXERA-D”
* 15: Vulcanization accelerator, manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., trade name “Noxera-CZ-G”.

Examples 1-2 and Comparative Examples 1-3
Each component described in the step (A) of Table 1 below was mixed in the ratio (parts by mass), and kneaded for 5 minutes with a Banbury mixer while adjusting the rotation speed so that the maximum temperature of the mixture was 160 ° C. After curing until the temperature of the mixture reaches 80 ° C. or less, each component described in step (B) of Table 1 is added in the proportion (part by mass) and adjusted so that the maximum temperature of the mixture becomes 110 ° C. or less. While kneading, a rubber composition was produced.

Brake characteristic test The rubber composition test samples (Examples 1 and 2 and Comparative Examples 1 to 3) obtained above were measured using a British portable skid tester at room temperature (25 ° C), Comparative example 1 was set to 100 and displayed as an index. The larger the value, the better the wet braking performance.

Abrasion resistance evaluation The test samples (Examples 1 and 2 and Comparative Examples 1 to 3) of the rubber composition obtained above were subjected to a sample rotation speed of 76 rpm / min and a grinding wheel rotation speed using an Akron abrasion tester. The amount of wear was measured under the conditions of 34 rpm / min, an inclination angle of 15 °, and a load of 1700 g. From this value, the wear resistance index was calculated by the following formula. The larger this value, the better the wear resistance.

Abrasion resistance index = (wear amount of the corresponding comparative rubber composition) / (wear amount of the rubber composition of the present invention) × 100

  The rubber composition of the present invention is excellent in wear resistance and wet braking properties. Therefore, it can utilize as a tread part (tire tread) of a pneumatic tire of various vehicles.

Claims (6)

A rubber composition in which hydrous titanium oxide and silica having a BET specific surface area of 100 to 210 m ² / g are blended with a rubber component. The rubber composition according to claim 1, wherein 80 parts by mass or more of diene rubber is contained in 100 parts by mass of the rubber component. The rubber composition according to claim 1 or 2, wherein the diene rubber is at least one selected from the group consisting of natural rubber, isoprene rubber, styrene-butadiene copolymer rubber, and butadiene rubber. The rubber composition according to any one of claims 1 to 3, comprising 1 to 80 parts by mass of hydrous titanium oxide and 20 to 150 parts by mass of silica with respect to 100 parts by mass of the rubber component. The rubber composition as described in any one of Claims 1-4 used for the tread part of a tire. A tire produced using the rubber composition according to any one of claims 1 to 5.