JP2006131682A - Rubber composition and pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition having a lower unvulcanized viscosity than those of conventional ones and a high dispersibility of silica, showing a high abrasion resistance and low rolling resistance in using as a tread member of a tire, and also capable of aiming at the improvement of braking property and steering stability on a wet road surface, and a tire by using the same. <P>SOLUTION: This rubber composition contains based on 100 pts.mass polymer, 10-200 pts.mass silica, 1-30 pts.mass 1 kind or ≥2 kinds of sulfur-containing silane compounds expressed by general formula (I): (R<SP>1</SP>O)<SB>3-p</SB>(R<SP>2</SP>)<SB>p</SB>SiR<SP>3</SP>SR<SP>4</SP>SR<SP>3</SP>Si(R<SP>2</SP>)<SB>p</SB>(OR<SP>1</SP>)<SB>3-p</SB>[wherein, R<SP>4</SP>is a divalent functional group expressed by general formula (II): R<SP>5</SP>S<SB>x</SB>R<SP>6</SP>S<SB>y</SB>R<SP>7</SP>] and 0.1-20 pts.mass compound having each of ≥1 reactive group on the polymer and adsorbable group to the silica in a same molecule. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rubber composition and a pneumatic tire, and in particular, the processability is good because the viscosity of unvulcanized rubber is low, and particularly when used in a tire tread, the wear resistance is high and the rolling resistance is high. The present invention relates to a rubber composition that is low and excellent in braking performance and handling stability on a wet road surface, and a tire using the rubber composition.

  Of the many fillers used in rubber compositions, silica has lower rolling resistance and higher braking and handling stability on wet road surfaces than carbon black, but in an unvulcanized state. Due to its high viscosity, workability such as multi-stage kneading is necessary. In addition, the dispersibility of the filler is low, vulcanization is delayed, and further, the breaking strength and wear resistance are greatly reduced.

  Therefore, usually, when silica is blended with rubber, a coupling agent is added to lower the unvulcanized viscosity and improve the modulus and wear resistance. However, since these coupling agents are expensive, there is a problem in that the production cost is increased by blending. Further, a dispersion improving additive is used to improve workability by improving the dispersibility of silica and lowering the unvulcanized viscosity, but there is a problem that the wear resistance is lowered. Furthermore, when a strong ionic compound is used as the dispersant, there are cases where deterioration of workability such as roll adhesion is observed.

In order to solve these problems, Patent Document 1 proposes a rubber composition in which a sulfur-containing silane compound having a specific structure is blended, and Patent Document 2 discloses a rubber in the same molecule together with an inorganic filler. There has been proposed a rubber composition in which a compound having at least one reactive group or an adsorbing group or reactive group for an inorganic filler is blended.
International Publication No. 2004/000930 Pamphlet JP 2003-176378 A

  According to Patent Documents 1 and 2, the viscosity of unvulcanized rubber is lower than before, the workability is good, and when used in a tire tread, the wear resistance is high, the rolling resistance is low, Although it has become possible to realize a rubber composition that can improve braking performance and handling stability on a wet road surface, with the advancement of today's technology, further improvements in these performances are desired.

  Accordingly, an object of the present invention is to provide a rubber composition having a low unvulcanized viscosity and a high dispersibility of silica that is higher in wear resistance and rolling resistance when used as a tread member of a tire. It is an object of the present invention to provide a rubber composition that can reduce the braking performance and handling stability of a wet road surface, and a tire using the rubber composition.

  As a result of intensive studies to solve the above problems, the present inventor has at least one reactive group for the polymer and one or more adsorption groups for the silica in the same molecule as the sulfur-containing silane compound having a specific structure in the rubber composition. It has been found that the above problems can be solved by blending a compound, and the present invention has been completed.

That is, the rubber composition of the present invention comprises 10 to 200 parts by mass of silica, 100 parts by mass of the polymer, the following general formula (I),
(R ¹ O) _3-p (R ² ) _p Si—R ³ —S—R ⁴ —S—R ³ —Si (R ² ) _p (OR ¹ ) _3-p (I),
(In the formula (I), R ¹ and R ² are each a hydrocarbon group having 1 to 4 carbon atoms, R ³ is a divalent hydrocarbon group having 1 to 15 carbon atoms, p is an integer of 0 to 2, R ⁴ Is the following general formula (II),
_{^{-R 5 -S x -R 6 -S y}} -R 7 - ··· (II)
In formula (II), R ⁵ , R ⁶ and R ⁷ may be the same or different and each has a linear or branched carbon number of 1 to 20 The divalent hydrocarbon group, the divalent aromatic group, or the divalent organic group containing a hetero atom other than a sulfur atom and an oxygen atom, and x and y each have an average value of 1 or more and less than 4. And 1 to 30 parts by mass of one or more sulfur-containing silane compounds represented by formula (1) to (2), and compounds 0.1 to 20 each having one or more reactive groups for the polymer and one or more adsorption groups for the silica in the same molecule. It is characterized by containing a mass part.

  The tire of the present invention is characterized by using a member containing the rubber composition.

  The rubber composition of the present invention has a low unvulcanized viscosity as a result of the combined use of a sulfur-containing silane compound having a specific structure and a compound having one or more reactive groups for the polymer and one or more adsorption groups for the silica in the same molecule. Is highly dispersible and excellent in processability. As a result, the productivity of rubber products can be greatly improved. Therefore, particularly when this rubber composition is used as a tire tread member, a tire having high wear resistance, low rolling resistance, and excellent wet road surface braking performance and steering stability can be obtained.

Hereinafter, preferred embodiments of the present invention will be described in detail.
The rubber composition of the present invention is 10 to 200 parts by mass of silica and 1 to 30 parts by mass of one or more sulfur-containing silane compounds represented by the above general formula (I) with respect to 100 parts by mass of the polymer. And a compound having at least one reactive group for the polymer and one or more adsorption groups for the silica in the same molecule. By using the sulfur-containing silane compound in combination with a compound having at least one reactive group for the polymer and one or more adsorption groups for the silica in the same molecule, the reaction between the alkoxy group in the silane compound and the silanol group on the silica can be achieved. It was found that the performance was far superior to the combined effect expected from the effect when each was used alone.

The sulfur-containing silane compound used in the present invention is a compound represented by the above general formula (I) having an organooxysilyl group at both ends of the molecule and a sulfide or polysulfide at the center of the molecule. In formula (I), R ¹ and R ² are each a hydrocarbon group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i- Examples thereof include a butyl group, a t-butyl group, a vinyl group, an allyl group, and an isopropenyl group. R ¹ and R ² may be the same or different. R ³ is a divalent hydrocarbon group having 1 to 15 carbon atoms, and includes, for example, a methylene group, an ethylene group, a propylene group, an n-butylene group, an i-butylene group, a hexylene group, a decylene group, and a phenylene group. And methylphenylethylene group. In addition, p is an integer of 0-2.

R ^{4 in the} general formula (I) is a divalent functional group represented by the general formula (II). In the formula (II), R ⁵ , R ⁶ and R ⁷ are linear or branched. A divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent aromatic group, or a divalent organic group containing a hetero atom other than a sulfur atom and an oxygen atom, such as methylene group, ethylene group, propylene Group, n-butylene group, i-butylene group, hexylene group, decylene group, phenylene group, methylphenylethylene group, etc., and nitrogen atom, phosphorus atom, etc. which are hetero atoms other than sulfur atom and oxygen atom are introduced into these groups Group. From the viewpoint of the desired effect of the present invention and production cost, R ⁵ , R ⁶ and R ⁷ are preferably hexylene groups. In addition, x and y are each an average value of 1 or more and less than 4, and in order to obtain the desired effect of the present invention, x and y are each preferably an average value of 2 or more and less than 4, more preferably 2 It is most preferable that it is 3 or less.

  The method for synthesizing the compound represented by the general formula (I) is not particularly limited, and can be synthesized by combining known reactions. The method described in International Publication No. 2004/000930 pamphlet can be used. It can be used suitably.

  Further, the sulfur-containing silane compound according to the present invention may produce a multimer such as a dimer or a trimer of the general formula (I) at the time of production, and 3 or more silicon atoms in one molecule. The sulfur-containing silane compound containing an atom may adversely affect the effect of the present invention. Therefore, in the present invention, when the sulfur-containing silane compound according to the present invention is blended, the content of the sulfur-containing silane compound having 3 or more silicon atoms per molecule is 30% by mass or less based on the rubber composition. It is preferable that the amount is 10% by mass or less, and most preferably not substantially contained.

  In the present invention, in order to obtain the desired effect of the present invention, 1 to 30 parts by mass of the sulfur-containing silane compound is blended with respect to 100 parts by mass of the polymer. It is preferable to be within the range of parts by mass.

  In the compound having at least one reactive group for the polymer and one or more adsorption groups for the silica in the same molecule of the present invention, the reactive group for the rubber is a group having a double bond, and the double bond is activated. The group which adjoins is preferable, and it is especially preferable that 1 type chosen from a carbonyl group, a carboxyl group, an oxycarbonyl group, and an amide group is adjacent to the non-aromatic conjugated double bond group or double bond. Here, the term “adjacent” means having one type selected from a carbonyl group, a carboxyl group, an oxycarbonyl group and an amide group at both ends or one side of the double bond.

  In the compound of the present invention, the reactive group is preferably a group derived from an unsaturated carboxylic acid selected from maleic acid, fumaric acid, itaconic acid, acrylic acid, methacrylic acid and sorbic acid. Most preferred is a group derived from an acid, itaconic acid or acrylic acid, particularly a group derived from maleic acid or acrylic acid. As the adsorbing group, a carboxyl group is preferable. The compound preferably further has an oxyalkylene group. By having an oxyalkylene group, compatibility with rubber is improved and affinity with silica is improved. The average added mole number of the oxyalkylene group is preferably in the range of 1 to 30 moles, more preferably 1 to 20 moles, particularly 2 to 15 moles per number of reactive groups to the rubber. Is preferred. Specific examples of the compound include mono ((meth) acryloyloxyalkyl) esters of polycarboxylic acids such as trimellitic acid, pyromellitic acid, and citric acid (where ((meth) acryloyl represents methacryloyl or acryloyl); (Poly) esters of unsaturated carboxylic acids such as maleic monomalate and oxycarboxylic acids; diols such as ethylene glycol, butanediol, hexanediol, cyclohexanedimethanol, and unsaturated such as maleic acid, fumaric acid, itaconic acid Examples include esters having a carboxyl group at both ends with dicarboxylic acid; N- (carboxyalkyl) maleamic acid such as N- (2-carboxyethyl) maleamic acid and the like.

  The polymer used in the present invention is not particularly limited as long as it can form a rubber composition, but is preferably a diene rubber. Specifically, natural rubber or various diene synthetic rubbers can be used, and diene synthetic rubber is particularly preferable. Diene synthetic rubbers include polybutadiene (BR), copolymers of butadiene and aromatic vinyl compounds, butadiene polymers such as copolymers of butadiene and other diene monomers, polyisoprene (IR), isoprene. And copolymers of aromatic vinyl compounds, isoprene polymers such as copolymers of isoprene and other diene monomers, butyl rubber (IIR), ethylene-propylene copolymers, and mixtures thereof. Of these, a butadiene polymer and an isoprene polymer are preferable, and a styrene-butadiene copolymer (SBR) is more preferable. The microstructure of SBR is not particularly limited, but among them, the amount of bound styrene is preferably 5% by mass to 60% by mass, and more preferably 15% by mass to 45% by mass. Furthermore, in the present invention, the styrene-butadiene copolymer is preferably contained in an amount of 50% by mass or more in the rubber component, and it is particularly preferable that the entire rubber component is a styrene-butadiene copolymer (SBR) alone. .

  Examples of the diene monomer include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 2-phenyl-1,3-butadiene, and the like. These may be used individually by 1 type, may mix 2 or more types, and also may be used by copolymerizing with other dienes, such as 1, 3- hexadiene. Of these, 1,3-butadiene is preferred.

The rubber composition of this invention mix | blends 10-200 mass parts of silica with respect to 100 mass parts of polymers. Silica is not particularly limited and includes, for example, wet silica (hydrous silicic acid), dry silica (anhydrous silicic acid), calcium silicate, aluminum silicate, etc. Among them, the effect of improving the fracture resistance, wet Wet silica is most preferred because it has the most remarkable effect of achieving both grip properties and low rolling resistance. Moreover, it is preferable that a BET surface area is the range of 40-350 m < ² > / g. When the BET surface area is within this range, there is an advantage that both rubber reinforcement and dispersibility in rubber can be achieved. From this viewpoint, the BET surface area is more preferably in the range of 80 to 300 m ² / g.

  In addition, in the rubber composition of the present invention, additives added to a normal rubber composition can be added to such an extent that the effects of the present invention are not impaired, and carbon black commonly used in the rubber industry, anti-aging Additives such as an agent, zinc oxide, stearic acid, antioxidant, ozone deterioration inhibitor, etc. can be appropriately blended.

  The rubber composition of the present invention is obtained by kneading using a kneader such as an open kneader such as a roll or a closed kneader such as a Banbury mixer, and vulcanized after molding to produce various rubber products. Applicable. For example, it can be used for tire applications such as tire treads, under treads, carcass, sidewalls, bead parts, vibration proof rubber, fenders, belts, hoses, and other industrial products. It is suitably used as a tread rubber.

  Moreover, in the tire of the present invention using the rubber composition, it is possible to obtain high wear resistance, low rolling resistance, and excellent performance in braking performance and steering stability on wet road surfaces. Examples of the gas filled in the tire include air or an inert gas such as nitrogen.

Next, the present invention will be described in more detail based on examples, but the present invention is not limited thereto. In addition, the physical property of the rubber composition obtained by each Example and the comparative example was measured with the following method.
(1) Mooney viscosity (ML _{1 + 4} )
Based on JIS K6300-1994, the Mooney viscosity (ML _{1 +} 4/130 ° C.) was measured at 130 ° C., and the value of Comparative Example 2 was indexed to 100. The smaller the Mooney viscosity, the higher the workability.
(2) Hardness Measured according to JIS K6253-1997, and the value of Comparative Example 2 was indexed as 100.
(3) Rebound resilience It was measured using a Dunlop trypometer in accordance with JIS K6255-1996. The measured values were indexed with the value of Comparative Example 2 as 100.
(4) Abrasion resistance (rubber composition)
The amount of wear at a slip rate of 60% at room temperature was measured using a Lambourn type wear tester. The results were indexed with the reciprocal of the amount of wear in each example as 100, with the value of the reciprocal of the amount of wear obtained in Comparative Example 2 being 100.

Moreover, the physical properties relating to the tire were measured by the following methods.
(5) Rolling resistance test The rolling resistance was rotated at a speed of 80 km / h using a rotating drum having a steel smooth surface with an outer diameter of 1707.6 mm and a width of 350 mm under a load of 4500 N (460 kg). It was measured and evaluated using the lameness method. The measured values were indexed with the value of Comparative Example 2 as 100. The larger this value, the better (smaller) the rolling resistance.
(6) Abrasion resistance (tire)
After traveling 20,000 km on a paved road surface with an actual vehicle, the remaining groove was measured, and the travel distance required for the tread to wear by 1 mm was relatively compared. It shows that abrasion resistance is so favorable that an index | exponent is large.

(Synthesis of sulfur-containing silane compounds)
First, a sulfur-containing silane compound was synthesized. 119 g (0.50 mol) of 3-mercaptopropyltriethoxysilane was charged into a 2 liter separable flask equipped with a nitrogen gas introduction tube, a thermometer, a Dimroth condenser and a dropping funnel, and sodium with 20% active ingredient under stirring. Ethanol solution in ethanol 151.2 (0.45 mol) was added. Then, it heated up at 80 degreeC and stirred for 3 hours. Then it was cooled and transferred to a dropping funnel.

Subsequently, 69.75 g (0.45 mol) of 1,6-dichlorohexane was charged into a separable flask similar to the above, and after raising the temperature to 80 ° C., the above-mentioned 3-mercaptopropyltriethoxysilane and sodium ethoxide were mixed. The reaction was slowly added dropwise. After completion of the dropwise addition, stirring was continued at 80 ° C. for 5 hours. Thereafter, the mixture was cooled, and the salt was filtered off from the resulting solution, and ethanol and excess 1,6-dichlorohexane were distilled off under reduced pressure. The obtained solution was distilled under reduced pressure to obtain 137.7 g of a colorless transparent liquid having a boiling point of 148 to 150 ° C./0.67 Pa (0.005 Torr). As a result of IR analysis, ¹ H-NMR analysis and mass spectral analysis (MS analysis), it is represented by (CH ₃ CH ₂ O) ₃ Si— (CH ₂ ) ₃ —S— (CH ₂ ) ₆ —Cl. It was a compound. The purity by gas chromatographic analysis (GC analysis) was 97.7%.

Next, in a 0.5 liter separable flask equipped with a nitrogen gas inlet tube, a thermometer, a Dimroth condenser and a dropping funnel, 80 g of ethanol, 10.92 g (0.14 mol) of anhydrous sodium sulfide, 6.73 g of sulfur ( 0.21 mol) was added and the temperature was raised to 80 ° C. While stirring this solution, 49.91 g (0.14 mol) of the compound represented by the general formula (CH ₃ CH ₂ O) ₃ Si— (CH ₂ ) ₃ —S— (CH ₂ ) ₆ —Cl synthesized above. Then, 10.85 g (0.07 mol) of 1,6-dichlorohexane was slowly added dropwise. After completion of dropping, stirring was continued at 80 ° C. for 10 hours. After completion of the stirring, the mixture was cooled, and the produced salt was filtered off. Then, ethanol as a solvent was distilled off under reduced pressure, whereby 55.1 g of a brown transparent solution was obtained. As a result of IR analysis, ¹ H-NMR analysis and supercritical chromatography analysis, it was found that general formula (CH ₃ CH ₂ O) ₃ Si— (CH ₂ ) ₃ —S— (CH ₂ ) ₆ —S _x — (CH _{2) 6 -S y - (CH} 2) 6 -S- (CH 2) 3 -Si (OCH 3 CH 2) 3, i.e., formula (I) and (II) R ¹ in the ethyl group, R ³ is It was confirmed that the propylene group, R ^{5 to} R ⁷ were hexylene groups, p = 0, and the average value of x and y was 2.5.

Examples 1-3
110 parts by mass of diene rubber (manufactured by Nippon Synthetic Rubber Co., Ltd., trade name “# 1712”) and 20 parts by mass of natural rubber were kneaded with a 1.8 L Banbury mixer at 70 rpm and a starting temperature of 80 ° C. for 30 seconds. 20 parts by mass of ISAF grade carbon black (trade name “SEAST 7HM” manufactured by Tokai Carbon Co., Ltd.), 50 parts by mass of silica (trade name “Nipsil AQ” manufactured by Nippon Silica Kogyo Co., Ltd.), and stearic acid 1 part by mass, 1.0 part by mass of the antioxidant 6PPD (N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine), and the sulfur-containing silane compound synthesized above (“Compound A And a compound having a reactive group for the polymer and an adsorbing group for the silica in the same molecule according to the formulation shown in Table 1 below, A polyester with acid (referred to as “Compound B”) or a polyester of butanediol and maleic acid (referred to as “Compound C”) was blended and kneaded until reaching 160 ° C., then discharged and rolled. Made into a sheet. Subsequently, after a remill operation was performed for 1 minute and 30 seconds at 70 rpm and a starting temperature of 80 ° C. with a 1.8 L Banbury mixer, it was discharged and formed into a sheet by a roll. After sufficiently cooling to room temperature, 3 parts by mass of active zinc, 0.5 parts by mass of vulcanization accelerator DM (dibenzothiazyl disulfide), vulcanization accelerator NS (Nt-butyl-2-benzothiazylsulfenamide) ) 1.0 part by mass and 1.5 parts by mass of sulfur were mixed and kneaded for 1 minute at 60 rpm and a starting temperature of 80 ° C. to obtain a rubber composition. The physical properties of the obtained rubber composition were measured. In Table 1, the addition amount is parts by mass with respect to 100 parts by mass of the rubber component.

  In addition, tires were produced by ordinary methods using each rubber composition. The tire size was 205 / 65R15, the rim 15 × 6JJ, and the internal pressure was 220 kPa. Using this tire, a rolling resistance test and an abrasion resistance test (tire) were carried out. The respective evaluation results are shown in Table 1.

Comparative Example 1
In Example 1, in place of the synthesized compound, a commercially available silane coupling agent (“Si69” manufactured by Degussa) (structure formula: (CH ₃ CH ₂ O) ₃ —Si— (CH ₂ ) ₃ —S ₄ Rubber in the same manner as in Example 1 except that 5.5 parts by mass of — (CH ₂ ) ₃ —Si (OCH ₂ CH ₃ ) ₃ ) is added to 100 parts by mass of the rubber component and no compound B is added. A composition was obtained. An evaluation result is shown in Table 1 (the test regarding a tire has not been implemented).

Comparative Example 2
In Example 1, in place of the synthesized compound, a commercially available silane coupling agent (“Si75” manufactured by Degussa) (structure: (CH ₃ CH ₂ O) ₃ —Si— (CH ₂ ) ₃ —S ₂ - (CH ₂₎ relative to _{3 -Si (OCH 2 CH 3)} 3) 100 parts by mass of the rubber component, was added 5.0 parts by weight, except that no addition of a compound B, the rubber in the same manner as in example 1 A composition and tire were obtained. The evaluation results are shown in Table 1.

Comparative Example 3
In Example 1, a rubber composition and a tire were obtained in the same manner as in Example 1 except that Compound B was not added. The evaluation results are shown in Table 1.

Comparative Example 4
In Example 1, instead of the synthesized compound, a commercially available silane coupling agent (“Si75” manufactured by Degussa) (Structural formula: (CH ₃ CH ₂ O) ₃ —Si— (CH ₂ ) ₃ —S ₂ - (CH _{2) 3} to _{-Si (OCH 2 CH 3) 3} ) 100 parts by mass of the rubber component, except for the addition of 5.0 parts by weight, to obtain a rubber composition and a tire in the same manner as in example 1 It was. The evaluation results are shown in Table 1.

（＊）表中の「併用化合物」とは「同一分子内にポリマーに対する反応基とシリカに対する吸着基とをする化合物」を表す。

(*) “Combination compound” in the table represents “a compound having a reactive group for a polymer and an adsorption group for silica in the same molecule”.

  As is clear from Table 1, Examples 1 to 3 all have the same or superior physical properties in terms of Mooney viscosity, hardness and abrasion resistance of the rubber composition as compared with Comparative Examples 1 to 4, and rubber In the tire made from the composition, both rolling resistance and wear resistance are good.

Claims (8)

10 to 200 parts by mass of silica with respect to 100 parts by mass of the polymer, the following general formula (I),
(R ¹ O) _3-p (R ² ) _p Si—R ³ —S—R ⁴ —S—R ³ —Si (R ² ) _p (OR ¹ ) _3-p (I),
(In the formula (I), R ¹ and R ² are each a hydrocarbon group having 1 to 4 carbon atoms, R ³ is a divalent hydrocarbon group having 1 to 15 carbon atoms, p is an integer of 0 to 2, R ⁴ Is the following general formula (II),
_{^{-R 5 -S x -R 6 -S y}} -R 7 - ··· (II)
In formula (II), R ⁵ , R ⁶ and R ⁷ may be the same or different and each has a linear or branched carbon number of 1 to 20 The divalent hydrocarbon group, the divalent aromatic group, or the divalent organic group containing a hetero atom other than a sulfur atom and an oxygen atom, and x and y each have an average value of 1 or more and less than 4. And 1 to 30 parts by mass of one or more sulfur-containing silane compounds represented by formula (1) to (2), and compounds 0.1 to 20 each having one or more reactive groups for the polymer and one or more adsorption groups for the silica in the same molecule. A rubber composition comprising: parts by weight.   The rubber composition according to claim 1, wherein x and y in the formula (II) are each an average value of 2 or more and 3 or less. The rubber composition according to claim 1 or 2, wherein R ⁵ , R ⁶ and R ⁷ in the formula (II) are hexylene groups.   The reactive group is a group derived from an unsaturated carboxylic acid selected from maleic acid, fumaric acid, itaconic acid, acrylic acid, methacrylic acid and sorbic acid, and the adsorptive group is a carboxyl group. 4. The rubber composition according to any one of 3. The rubber composition according to claim 1, wherein the silica has a BET surface area of 40 to 350 m ² / g.   The rubber composition according to any one of claims 1 to 5, wherein the polymer is a diene rubber.   A tire using a member containing the rubber composition according to claim 1.   The tire according to claim 7, wherein the member is a tire tread.