JP2008156446A - Rubber composition for specific tire member and tire obtained using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition for a specific tire member that reduces rolling resistance and enhances processability and a tire obtained using the same. <P>SOLUTION: The rubber composition for a specific tire member comprises 100 pts.wt. of a diene rubber, 5-150 pts.wt. of carbon black having a nitrogen adsorption specific surface area of at most 100 m<SP>2</SP>/g, 5-80 pts.wt. of silica having a nitrogen adsorption specific surface area of at most 100 m<SP>2</SP>/g, and 2-12 pts.wt., based on 100 pts.wt. of silica, of a silane coupling agent. The tire is obtained using the same. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a specific rubber composition for a tire member and a tire using the rubber composition.

  In order to reduce the rolling resistance of a tire, it is generally known to add silica as a filler to a tread. It is known that when silica is added to the tread, wet traction performance can be improved at the same time. Here, since application of only the tread has a limit in the effect of reducing rolling resistance, it is necessary to apply silica also to other tire members.

  However, sidewalls, base treads, clinch apex, and inner liners use carbon black with a large particle size. Even if the carbon black with a large particle size is changed to silica, the rolling resistance can be sufficiently reduced. Was not obtained.

  On the other hand, a rubber composition for base tread containing silica-containing carbon black and silica is also known (see, for example, Patent Document 1). However, there is still room for improvement in extrudability (rubber burnt).

JP 2005-248020 A

  An object of this invention is to provide the rubber composition for specific tire members which can reduce rolling resistance, and can improve workability, and a tire using the same.

The present invention is, with respect to the diene rubber 100 parts by weight, 5 to 100 parts by weight of nitrogen adsorption specific surface area of not more than carbon black 100 m ² / g, and nitrogen adsorption specific surface area of the 100 m ² / g or less of silica The present invention relates to a rubber composition for sidewalls containing 5 to 80 parts by weight and containing 2 to 12 parts by weight of a silane coupling agent with respect to 100 parts by weight of the silica.

  The present invention also relates to a tire having a sidewall using the rubber composition for a sidewall.

The present invention is, with respect to the diene rubber 100 parts by weight, 5 to 100 parts by weight of nitrogen adsorption specific surface area of not more than carbon black 100 m ² / g, and nitrogen adsorption specific surface area of the 100 m ² / g or less of silica The present invention relates to a rubber composition for a base tread containing 5 to 80 parts by weight and containing 2 to 12 parts by weight of a silane coupling agent with respect to 100 parts by weight of the silica.

  The present invention also relates to a tire having a base tread using the rubber composition for base tread.

The present invention is, with respect to the diene rubber 100 parts by weight, 5 to 100 parts by weight of nitrogen adsorption specific surface area of not more than carbon black 100 m ² / g, and nitrogen adsorption specific surface area of the 100 m ² / g or less of silica The present invention relates to a rubber composition for clinch apex containing 5 to 80 parts by weight and containing 2 to 12 parts by weight of a silane coupling agent with respect to 100 parts by weight of the silica.

  The present invention also relates to a tire having a clinch apex using the rubber composition for clinch apex.

The present invention is, with respect to the diene rubber 100 parts by weight, 5 to 150 parts by weight of nitrogen adsorption specific surface area of 80 m ² / g The following carbon black, and the nitrogen adsorption specific surface area of the 100 m ² / g or less of silica The present invention relates to a rubber composition for an inner liner containing 5 to 80 parts by weight and containing 2 to 12 parts by weight of a silane coupling agent with respect to 100 parts by weight of the silica.

  The present invention also relates to a tire having an inner liner using the rubber composition for an inner liner.

  According to the present invention, for a specific tire member that can reduce rolling resistance and improve workability by containing a predetermined amount of diene rubber, predetermined carbon black, predetermined silica, and silane coupling agent. A rubber composition and a tire using the rubber composition can be provided.

  The rubber composition of the present invention contains a diene rubber, carbon black, silica, and a silane coupling agent.

  The diene rubber is not particularly limited. For example, natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), butyl rubber (IIR), halogenated butyl rubber (X-IIR). ), Chloroprene rubber (CR), ethylene propylene diene rubber (EPDM), halides of copolymers of isomonoolefin and paraalkyl styrene, etc. These diene rubbers are not particularly limited and are used alone. You may use it in combination of 2 or more types.

  The carbon black used in the present invention has a large particle size.

The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is 100 m ² / g or less, preferably 90 m ² / g or less, more preferably 80 m ² / g or less. If the N ₂ SA of the carbon black exceeds 100 m ² / g, the low heat build-up of the rubber composition after vulcanization is inferior and the fuel efficiency is deteriorated. Further, N ₂ SA of carbon black is preferably 25 m ² / g or more, more preferably 35 m ² / g or more. When N ₂ SA of carbon black is less than 25 m ² / g, there is a tendency that a sufficient reinforcing effect cannot be obtained. In the present invention, N ₂ SA of carbon black is for a sidewall, a base tread, preferably 25~100m ² / g as a clinch apex, preferably 25~80m ² / g is as for an inner liner .

  The content of carbon black is 5 parts by weight or more, preferably 40 parts by weight or more with respect to 100 parts by weight of the diene rubber. If the carbon black content is less than 5 parts by weight, the electrical resistance will be high, so it will be necessary to take measures for electrical conductivity. Furthermore, the exterior of the tire will not be sufficiently blackened for the parts exposed to the outside, and the merchantability will be reduced. To do. The carbon black content is 150 parts by weight or less, preferably 120 parts by weight or less, and more preferably 100 parts by weight or less. When the content of carbon black exceeds 150 parts by weight, the low heat build-up property is inferior and the fuel efficiency is deteriorated. In the present invention, the content of carbon black is preferably 5 to 100 parts by weight for sidewalls, base treads, and clinch apex, and preferably 5 to 150 parts by weight for inner liners.

  Silica includes those prepared by a wet method and those prepared by a dry method, but is not particularly limited.

The N ₂ SA of silica is 100 m ² / g or less, preferably 70 m ² / g or less. When the N ₂ SA of silica exceeds 100 m ² / g, the effect of improving the low exothermic property is not observed with respect to carbon black having a large particle size. Further, N ₂ SA of silica is preferably 25 m ² / g or more, and more preferably 40 m ² / g or more. When the N ₂ SA of silica is less than 25 m ² / g, there is a tendency that a sufficient reinforcing effect cannot be obtained.

  The content of silica is 5 parts by weight or more, preferably 20 parts by weight or more with respect to 100 parts by weight of the diene rubber. When the content of silica is less than 5 parts by weight, a sufficient improvement effect of low exothermic property cannot be obtained. The silica content is 80 parts by weight or less, preferably 60 parts by weight or less. When the content of silica exceeds 80 parts by weight, the workability deteriorates.

  The silane coupling agent is not particularly limited, and those conventionally used in combination with silica can be used in the rubber industry. For example, bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-tri Ethoxysilylethyl) tetrasulfide, bis (4-triethoxysilylbutyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (4-trimethoxysilyl) Butyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (2-triethoxysilylethyl) trisulfide, bis (4-triethoxysilylbutyl) trisulfide, bis (3-trimethoxysilylpropyl) Trisulfide Bis (2-trimethoxysilylethyl) trisulfide, bis (4-trimethoxysilylbutyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, bis (2-triethoxysilylethyl) disulfide, bis (4- Triethoxysilylbutyl) disulfide, bis (3-trimethoxysilylpropyl) disulfide, bis (2-trimethoxysilylethyl) disulfide, bis (4-trimethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N, N -Dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-trimethoxysilane Ruethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxy Sulfide series such as silylpropyl methacrylate monosulfide, mercapto series such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, vinyltriethoxysilane , Vinyl type such as vinyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-amino Amino) such as ethyl) aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycid Glycidoxy type such as xylpropylmethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, nitro type such as 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3 -Chloro series such as chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane, 2-chloroethyltriethoxysilane, and the like.

  The content of the silane coupling agent is 2 parts by weight or more, preferably 5 parts by weight or more with respect to 100 parts by weight of silica. When the content of the silane coupling agent is less than 2 parts by weight, the reinforcing effect of silica cannot be sufficiently exerted, and the effect of improving the low heat build-up becomes small. The content of the silane coupling agent is 12 parts by weight or less, preferably 10 parts by weight or less. If the content of the silane coupling agent exceeds 12 parts by weight, the effect of improving the low heat build-up will not appear and the cost will increase.

  In the rubber composition of the present invention, in addition to the diene rubber, carbon black, silica and silane coupling agent, compounding agents conventionally used in the rubber industry, such as process oil, wax, various anti-aging agents, Vulcanizing agents such as stearic acid, zinc oxide and sulfur, various vulcanization accelerators and the like can be appropriately contained as required.

  The rubber composition of the present invention is prepared by a general method. That is, the rubber composition of the present invention is prepared by kneading the diene rubber, alkylphenol / sulfur chloride condensate and, if necessary, the compounding agent with a Banbury mixer, kneader, open roll, etc., and then vulcanizing. be able to.

  The rubber composition of the present invention is suitably used as a sidewall, a base tread, a clinch apex, and an inner liner, among tire members, because the effect of improving fuel economy performance is expected by reducing heat generation. Is.

  The tire of the present invention is produced by a usual method using the rubber composition as a sidewall, base tread, clinch apex or inner liner. That is, the rubber composition is extruded into the shape of a tire sidewall, base tread, clinch apex or inner liner at an unvulcanized stage, and pasted together with other tire members on a tire molding machine by a usual method. Together, an unvulcanized tire is formed. The unvulcanized tire can be heated and pressurized in a vulcanizer to obtain the tire of the present invention.

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

Hereinafter, various chemicals used in Examples and Comparative Examples will be described together.
Natural rubber (NR): RSS # 3
Butadiene rubber (BR) (1): BR150B manufactured by Ube Industries, Ltd.
BR (2): BR130B manufactured by Ube Industries, Ltd.
Butyl rubber (IIR): Chlorobutyl 1068 from Exxon Chemical Company
Carbon Black (1): Show Black N550 (N ₂ SA: 41 m ² / g) manufactured by Cabot Japan
Carbon Black (2): Show Black N351 (N ₂ SA: 71 m ² / g) manufactured by Cabot Japan
Silica (1): Ultrasil 360 (N ₂ SA: 50 m ² / g) manufactured by Degussa
Silica (2): Ultrasil VN3 manufactured by Degussa (N ₂ SA: 200 m ² / g)
Silane coupling agent: Si69 (bis (3-triethoxysilylpropyl) tetrasulfide) manufactured by Degussa
Process oil: Diana Process AH-24 manufactured by Idemitsu Kosan Co., Ltd.
Wax: Sunnock N manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
Anti-aging agent: Antigen 6C (N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine) manufactured by Sumitomo Chemical Co., Ltd.
Stearic acid: Stearic acid “Kashiwa” manufactured by Nippon Oil & Fats Co., Ltd.
Zinc oxide: Zinc oxide sulfur manufactured by Mitsui Mining & Smelting Co., Ltd .: Sulfur powder vulcanization accelerator manufactured by Karuizawa Sulfur Co., Ltd .: Noxeller CZ (N-cyclohexyl-2-benzothia manufactured by Ouchi Shinsei Chemical Co., Ltd.) Zolylsulfenamide)

Examples 1-8 and Comparative Examples 1-8
According to the formulation shown in Tables 1 to 4, using a Banbury mixer, chemicals other than sulfur and a vulcanization accelerator were kneaded for 3 minutes at 150 ° C. to obtain a kneaded product. Next, sulfur and a vulcanization accelerator are added to the obtained kneaded material, and kneaded for 5 minutes under the condition of 80 ° C. using an open roll, and the unvulcanized examples 1 to 8 and comparative examples 1 to 8 are not added. A vulcanized rubber composition was obtained. In the following evaluation tests, Comparative Examples 1 and 2 and Comparative Examples 3 to 4 (Rubber Composition for Base Tread) were used in Examples 1 and 2 and Comparative Examples 1 and 2 (Rubber Composition for Sidewalls). ) For Comparative Example 3, Examples 5 to 6 and Comparative Examples 5 to 6 (rubber composition for clinch apex), Comparative Example 5 for Examples 7 to 8 and Comparative Examples 7 to 8 (rubber compositions for inner liners) Comparative Example 7 was used as the standard formulation.

(Processability)
A test piece of a predetermined size was prepared from the unvulcanized rubber composition, and it was used for 1 minute using a Mooney viscosity tester manufactured by Shimadzu Corporation according to JIS K 6300 “Testing method for unvulcanized rubber”. Under the temperature condition of 130 ° C. heated by preheating, the Mooney viscosity (ML _{1 +} 4/130 ° C.) of the unvulcanized rubber composition after 4 minutes was measured and the standard was measured. The Mooney viscosity index of the blend was set to 100, and the Mooney viscosity of each blend was indicated by an index according to the following formula. In addition, it shows that Mooney viscosity is reduced and processability is excellent as the Mooney viscosity index is large.
(Mooney Viscosity Index) = (Mooney Viscosity of Reference Formula)
÷ (Mooney viscosity of each formulation) x 100

(Rolling resistance)
The unvulcanized rubber composition was press vulcanized at 175 ° C. for 12 minutes under a pressure condition of 20 kgf to obtain vulcanized rubber compositions of Examples 1 to 8 and Comparative Examples 1 to 8.

Using a viscoelastic spectrometer VES manufactured by Iwamoto Seisakusho Co., Ltd., the loss tangent (tan δ) of the vulcanized rubber composition at 70 ° C. was measured under the conditions of a frequency of 10 Hz, an initial strain of 10% and a dynamic strain of 2%. The rolling resistance index of the reference blend was set to 100, and the tan δ of each blend was displayed as an index according to the following formula. In addition, it shows that rolling resistance is reduced and it is excellent, so that a rolling resistance index | exponent is large.
(Rolling resistance index) = (tan δ of reference formulation) / (tan δ of each formulation) × 100

  The evaluation result of the said test is shown to Tables 1-4.

Claims (8)

For 100 parts by weight of diene rubber,
5-100 parts by nitrogen adsorption specific surface area of not more than carbon black 100 m ² / g, and nitrogen adsorption specific surface area of 100 m ² / g to less silica containing 5 to 80 parts by weight,
For 100 parts by weight of the silica,
A rubber composition for a sidewall containing 2 to 12 parts by weight of a silane coupling agent. A tire having a sidewall using the rubber composition for a sidewall according to claim 1. For 100 parts by weight of diene rubber,
5-100 parts by nitrogen adsorption specific surface area of not more than carbon black 100 m ² / g, and nitrogen adsorption specific surface area of 100 m ² / g to less silica containing 5 to 80 parts by weight,
For 100 parts by weight of the silica,
A rubber composition for a base tread containing 2 to 12 parts by weight of a silane coupling agent. A tire having a base tread using the rubber composition for a base tread according to claim 3. For 100 parts by weight of diene rubber,
5-100 parts by nitrogen adsorption specific surface area of not more than carbon black 100 m ² / g, and nitrogen adsorption specific surface area of 100 m ² / g to less silica containing 5 to 80 parts by weight,
For 100 parts by weight of the silica,
A rubber composition for clinch apex containing 2 to 12 parts by weight of a silane coupling agent. A tire having a clinch apex using the rubber composition for a clinch apex according to claim 5. For 100 parts by weight of diene rubber,
5 to 150 parts by weight of carbon black having a nitrogen adsorption specific surface area of 80 m ² / g or less, and 5 to 80 parts by weight of silica having a nitrogen adsorption specific surface area of 100 m ² / g or less,
For 100 parts by weight of the silica,
A rubber composition for an inner liner containing 2 to 12 parts by weight of a silane coupling agent. A tire having an inner liner using the rubber composition for an inner liner according to claim 7.