JP2000230082A - Rubber composition and pneumatic tire made therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rubber composition improved in wet performances and chunk performances by including a conjugated diene compound/vinylaromatic hydrocarbon compound copolymer with a reinforcing filler comprising a hydrous silicate and a carbon black and surface-treated with an organosilicon compound, and a silane coupling agent. SOLUTION: This composition comprises 100 pts.wt. copolymer, 70-110 pts.wt. reinforcing filler comprising 40-100 wt.% hydrous silicate satisfying the requirements: 0.95>=BET: 1/BET:1>=0.6; 1.1>=PO:2/PO:1>=0.9; 300>=PO:2>=100; and 300>=BET:2>=125 and 60-0 wt.% carbon black and surface-treated with 1-20 wt.% (based on the hydrous silicate) organosilicon compound, and 2-15 wt.%, based on the surface-treated hydrous silicate, silane coupling agent. BET:1, BET:2, PO:1, and PO:2 are the specific surface areas m2/g of the hydrated silicate before and after the surface treatment as measured by the nitrogen adsorptiorr method and the mercury porosimetry.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition and a pneumatic tire using the same, and more particularly to a rubber composition having a reinforcing property suitable for a tread for a high-performance tire, and particularly to a steering stability on a wet road surface. TECHNICAL FIELD The present invention relates to a rubber composition having improved performance (wet performance) and chunk performance (tread chipping performance) during circuit running and the like, and a pneumatic tire using the rubber composition.

[0002]

2. Description of the Related Art Conventionally, carbon black has been frequently used as a reinforcing filler for rubber. This is because carbon black can provide high reinforcing properties and excellent wear resistance as compared with other fillers. On the other hand, with the recent social demands for energy saving, when reducing the heat generation of tire rubber for the purpose of saving fuel consumption of automobiles, it is necessary to reduce the filling amount of carbon black or use carbon black with a large particle size. It is conceivable, however, that in any case, it is inevitable that the reinforcing property, the wear resistance, and the grip property on a wet road surface are reduced.

On the other hand, there has been disclosed a technique in which silica is blended with a rubber composition for a tire tread to improve the balance between wet performance and rolling resistance performance (JP-A-3-252431, JP-A-5-271377). No.). However, studies by the present inventors have revealed that the use of silica deteriorates the chunk performance of the tire particularly under severe running conditions such as a circuit. In recent years, even for high performance tires, there is a high demand for wet performance, and it is necessary to increase the silica ratio (the ratio of silica to the total reinforcing filler). However, when the ratio of silica is increased, as described above, in an ultra-high performance tire on the premise of ensuring circuit running performance, chunk performance is inevitably reduced, and a certain ratio or more of silica is used for the tread rubber. I couldn't do that.

[0004] A pneumatic tire using a rubber composition obtained by blending silica whose surface is treated with an organosilicon compound has been proposed (Japanese Patent Application Laid-Open No. H8-245838). The purpose of the present invention is to improve wear resistance and rolling resistance, which is different from the present invention.

[0005]

SUMMARY OF THE INVENTION The present invention has a reinforcing property suitable for a tread for a high-performance tire under such a circumstance, and particularly, a steering stability on a wet road surface (wet performance).
It is an object of the present invention to provide a rubber composition having improved chunk performance in circuit running and the like, and a pneumatic tire using the rubber composition.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, the chunk property during circuit running is proportional to the magnitude of the breaking energy of rubber. Focusing on the fact that the low breaking energy caused by using silica with low reinforcing properties compared to carbon black is a cause of deteriorating chunk performance, a specific diene rubber was surface treated with an organosilicon compound. By blending hydrated silicic acid having specific properties and carbon black at a predetermined ratio,
It has been found that a rubber composition having improved wet performance and chunk performance can be obtained. The present invention has been completed based on such findings.

That is, the present invention relates to (1) (A) a copolymer of a conjugated diene compound and a vinyl aromatic hydrocarbon compound, (B) (1) 1 to 20% by weight of an organosilicon compound (based on hydrous silicic acid) ) And the relational expression 0.95 ≧ BET (2) / BET (1) ≧ 0.6 1.1 ≧ PO (2) / PO (1) ≧ 0.9 300 ≧ PO (2) ≧ 100 300 ≧ BET (2) ≧ 125 (BET (1) and BET (2) are nitrogen adsorption specific surface area (m ² / g) of hydrous silicic acid before and after surface treatment, respectively, PO (1 ) And PO (2) indicate the specific surface area (m ² / g) of the hydrous silicic acid before and after the surface treatment, respectively, of the hydrous silicic acid. B) a reinforcing filler consisting of 60 to 0% by weight of carbon black, and (C) silane It contains a pulling agent, and the content of the component (B) is 70 to 110 parts by weight per 100 parts by weight of the component (A), and the content of the component (C) is the surface of the component (B) (A). 2 to 15% by weight based on the weight of the treated hydrous silicic acid;
(D) the rubber composition according to the above (1), which contains 35 to 60 parts by weight of a softener, and (3) the above (1),
It is intended to provide a pneumatic tire using the rubber composition of (2) for a tread rubber.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the rubber composition of the present invention,
(A) As the rubber component, a copolymer of a conjugated diene compound and a vinyl aromatic hydrocarbon compound is used. In the present invention, the copolymer of the component (A) preferably contains 32 to 40% by weight of a vinyl aromatic hydrocarbon compound unit and 15% by weight or more of a vinyl binding component. If the content of the vinyl aromatic hydrocarbon compound unit is less than 32% by weight, grip properties may be reduced, and the content may be 40% by weight.
If it exceeds, the wear resistance may be reduced. In consideration of gripping properties and abrasion resistance, the copolymer preferably contains 35 to 40% by weight of a vinyl aromatic hydrocarbon compound unit and 18 to 25% by weight of a vinyl binding component.

As the copolymer (A), styrene-butadiene rubber (SBR) is particularly preferred. As the styrene-butadiene rubber, those produced by any polymerization method such as an emulsion polymerization method and a solution polymerization method can be used. In the rubber composition of the present invention, as long as the object of the present invention is not impaired, if desired,
As the component (A), a part of the copolymer of the conjugated diene compound and the vinyl aromatic hydrocarbon compound is replaced with another rubber, for example, natural rubber, polyisoprene synthetic rubber (IR), polybutadiene rubber (BR), acrylonitrile. Those substituted with butadiene rubber (NBR), chlorobron rubber (CR), butyl rubber (IIR) and the like can also be used.

In the rubber composition of the present invention, as the reinforcing filler of the component (B), (a) hydrous silicic acid alone surface-treated with an organosilicon compound or surface-treated hydrous silicic acid of the component (a) A combination of an acid and (ii) carbon black is used. The surface-treated hydrous silicate of the component (A) includes a nitrogen adsorption specific surface area (m
² / g) as BET (1), the nitrogen adsorption specific surface area (m ² / g) after the surface treatment as BET (2), and the mercury intrusion method specific surface area (m ² / g) before the surface treatment as PO (1). ), When the specific surface area (m ² / g) of the mercury intrusion method after the surface treatment is defined as PO (2), the relational expression 0.95 ≧ BET (2) / BET (1) ≧ 0.6 1.1 ≧ PO (2) / PO (1) ≧ 0.9 300 ≧ PO (2) ≧ 100 300 ≧ BET (2) ≧ 125

When the value of BET (2) / BET (1) is 0.
If it is less than 6, the surface area of the hydrous silicic acid after the surface treatment becomes too small, and the reinforcing property is not sufficiently exhibited. The effect of improving the variation in physical properties of rubber is not sufficiently exhibited, and none of the objects of the present invention can be achieved. In consideration of the reinforcing property, the shape stability of the extruded product, the variation in physical properties, and the like, the preferable value of BET (2) / BET (1) is 0.7 to
0.9. Further, the mercury intrusion specific surface area (PO) of the hydrous silicic acid has a very high correlation with the rubber properties, and when the PO is changed by the surface treatment, the rubber properties such as abrasion resistance, reinforcing properties, and viscoelasticity change. Therefore, in the present invention, the value of PO (2) / PO (1) needs to be in the range of 0.9 to 1.1, and particularly preferably in the range of 0.95 to 1.05. .

Further, if PO (2) is less than 100 m ² / g or BET (2) is less than 125 m ² / g, the reinforcing property is not sufficiently exhibited, and PO (2) or BET
If (2) exceeds 300 m ² / g, the cohesive force between hydrated silicic acids increases, the dispersibility deteriorates, and the reinforcing properties decrease. From the viewpoints of reinforcement, dispersibility, etc., the preferred range of the PO (2) is 120 to 250 m ² / g,
The preferred range of (2) is 130~250m ² / g. The surface-treated hydrous silicic acid used as the component (a) has a pore volume of at most 1.1 ml / g by a mercury intrusion method with a diameter of 1000 mm or less, and an equilibrium water content at a temperature of 25 ° C and a relative humidity of 90%. Water content of 6% by weight or less, at a temperature of 25 ° C. and a relative humidity of 50%;
2.5% by weight difference from equilibrium moisture at 90 ° C and 90% relative humidity
The following are preferred.

When the equilibrium water content at a temperature of 25 ° C. and a relative humidity of 90% exceeds 6% by weight, water evaporates in the extrusion step, the porosity in the extruded product becomes large, and the shape stability is insufficient. There is a possibility that. From the viewpoint of the shape stability of the extruded product, the equilibrium water content is particularly preferably 5% by weight or less. If the difference between the equilibrium moisture content at a temperature of 25 ° C. and a relative humidity of 50% and the equilibrium moisture content at a temperature of 25 ° C. and a relative humidity of 90% exceeds 2.5% by weight, the physical properties of rubber may vary due to humidity. Become. The difference in the equilibrium water content is particularly preferably 2% by weight or less from the viewpoint of reducing the variation in rubber properties.

In the present invention, the surface-treated hydrated silicic acid of the component (a) is prepared by using the following organosilicon compound at a ratio of 1 to 20% by weight based on the hydrated silicic acid,
It is prepared by performing a surface treatment of hydrous silicic acid at a temperature of 00C, preferably 250-350C. If the amount of the organosilicon compound is less than 1% by weight, the effect of enhancing the reinforcing property by the surface treatment is not sufficiently exhibited, and if it exceeds 20% by weight, the silane coupling agent reacts with Si—
Since the OH site is covered, the effect of the silane coupling agent is reduced. Considering the effect of improving the reinforcing property and the effect of blending the silane coupling agent, the amount of the organosilicon compound is preferably in the range of 1 to 5% by weight. It is preferable that the amount of the organosilicon compound used is appropriately selected depending on the surface area of the hydrous silicic acid to be treated, that is, the number of Si-OH sites. In this surface treatment,
Examples of the organosilicon compounds include dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, and various modifications such as amino modification, alkyl modification, fluorine modification, carbinol modification, mercapto modification, polyether modification, epoxy modification, and methacryl modification. Silicone oil and the like, and cyclic dimethylsiloxane, trimethylsilanol, trimethylmonochlorosilane, dimethyldimethoxysilane, diphenyldimethoxysilane, hexamethyldisilane, decyltriethoxysilane, and the like are used. These may be used alone,
Two or more kinds may be used in combination. At the time of the treatment, an alkali catalyst such as KOH, (CH ₃ ) ₄ NOH, (nC ₄ H ₉ ) ₄ POH or an acid catalyst such as sulfuric acid or hydrochloric acid can be used.

In the present invention, the surface-treated hydrous silicic acid of the component (a) may be used alone or in combination of two or more. On the other hand, the carbon black of the component (b) is classified into channel black, furnace black, acetylene black, thermal black and the like depending on the production method, and any of them can be used. In the present invention, as the reinforcing filler of the component (B), a filler composed of 40 to 100% by weight of the surface-treated hydrated silica of the component (A) and 60 to 0% by weight of the carbon black (B) is used. The compounding ratio of the surface treated hydrous silicic acid is 4
If the amount is less than 0% by weight, the wet performance becomes insufficient. From the viewpoint of wet performance, the compounding ratio of the component (a) to the component (b) is preferably such that the component (a) is 50 to 100% by weight and the component (b) is 50 to 0% by weight. Preferably, the component (a) is in the range of 70 to 95% by weight, and the component (B) is in the range of 30 to 5% by weight.

In the present invention, the reinforcing filler of the component (B) is used in an amount of 70 per 100 parts by weight of the component (A).
It is blended in the range of １１０110 parts by weight. This compounding amount is 70
If the amount is less than 10 parts by weight, the grip on wet and dry road surfaces is reduced. If the amount is more than 110 parts by weight, abrasion resistance and chunking properties are reduced. From the viewpoint of the balance between grip properties, abrasion resistance and chunk properties, the amount of the component (B) is from 70 to 1
A range of 00 parts by weight is preferred. In the rubber composition of the present invention, in order to further improve the effect of the surface-treated hydrated silicic acid in the component (B), a silane coupling agent is blended as the component (C). As the silane coupling agent, it can be used any of the conventionally known silane coupling agents, particularly the general formula _{(I) A m B 3-} m Si-XS a -X-SiA m B _3-m ·· (I) (in the formula, a _{C n H 2n + 1 O (} n is an integer of 1 to 3) or a chlorine atom, B is an alkyl group having 1 to 3 carbon atoms, X is 1 carbon atoms
To 9 saturated or unsaturated alkylene groups or 7 carbon atoms
May be an integer of 1 to 3 and may have a distribution. However, when m is 1, two B's may be the same or different, and when m is 2 or 3, two or three A's may be the same or different. Compounds represented by), the general formula _{(II) A m B 3-} m Si-XY ··· (II) ( In the formula, A _{C n H 2n + 1 O (} n is an integer of 1 to 3) or A chlorine atom, B is an alkyl group having 1 to 3 carbon atoms, X is 1 carbon atom
To 9 saturated or unsaturated alkylene groups or 7 carbon atoms
To 15 are arylene groups, Y is a mercapto group, a vinyl group,
An amino group, a glycidoxy group or an epoxy group, m is 1 to 3
Indicates an integer. However, when m is 1, two B's may be the same or different, and when m is 2 or 3, two or three A's may be the same or different. Compounds represented by), and the general formula _{(III) A m B 3-} m Si-XS a -Z ··· (III) ( In the formula, A is _{C n H 2n + 1 O (} n 1~3 ) Or a chlorine atom, B is an alkyl group having 1 to 3 carbon atoms, and X is 1 carbon atom.
To 9 saturated or unsaturated alkylene groups or 7 carbon atoms
To 15 are arylene groups, Z is a benzothiazolyl group, N,
An N-dimethylthiocarbamoyl group or a methacryloyl group, m is an integer of 1 to 3, and a is an integer of 1 or more and may have a distribution. However, when m is 1, two B's may be the same or different, and when m is 2 or 3, two or three A's may be the same or different. It is preferable to use at least one selected from the compounds represented by the formula (1).

Examples of the silane coupling agent represented by the general formula (I) include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (3- Methyldimethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylethyl) tetrasulfide,
Bis (3-triethoxysilylpropyl) disulfide, bis (3-trimethoxysilylpropyl) disulfide, bis (3-triethoxysilylpropyl) trisulfide and the like are useful as silane coupling agents represented by the general formula (II). Examples include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, 3-aminopropyltriethoxysilane,
Aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, etc. are silane coupling agents represented by the general formula (III) Examples thereof include 3-trimethoxysilylpropyl-N, N-dimethylcarbamoyltetrasulfide, 3-trimethoxysilylpropylbenzothiazolyltetrasulfide, 3-trimethoxysilylpropylmethacryloylmonosulfide, and the like. In the present invention, the silane coupling agent of the component (C) may be used alone or in combination of two or more. The compounding amount is 2 to 1 with respect to the surface-treated hydrous silicic acid of the component (B) (a).
It is selected in the range of 5% by weight. If the amount is less than 2% by weight, the viscosity of the rubber composition is significantly increased and workability deteriorates. If the amount exceeds 15% by weight, extrusion workability due to the generation of alcohol deteriorates. In the rubber composition of the present invention, a softener can be further added as a component (D), if desired, in order to improve workability and the like. The softener is not particularly limited, and may be appropriately selected from those conventionally used as rubber softeners. Examples of the softener include mineral oils, vegetable oils, and synthetic oils. Examples of the mineral oils include process oils such as naphthene and paraffin, and examples of the vegetable oils include castor oil, cottonseed oil, and the like. Linseed oil, rapeseed oil, soybean oil, palm oil, coconut oil, peanut oil, wood wax,
Pine oil, olive oil and the like. Examples of the synthetic oils include polyisobutylene-based oils.

These softeners may be used alone or in combination of two or more. The compounding amount is usually 35 to 6 per 100 parts by weight of the component (A).
It is selected in the range of 0 parts by weight. When the amount is less than 35 parts by weight, the effect of reducing the viscosity of the rubber composition is not sufficiently exhibited,
Workability is hardly improved, and if it exceeds 60 parts by weight, wear resistance and chunking properties are deteriorated. In consideration of workability, abrasion resistance, chunking properties, etc., the amount of the softener is preferably in the range of 40 to 55 parts by weight. In the rubber composition of the present invention, various chemicals usually used in the rubber industry, such as a vulcanizing agent, a vulcanization accelerator, an antioxidant, and an anti-scorch agent, as long as the object of the present invention is not impaired. , Other fillers, zinc white, stearic acid, and the like. And the rubber composition of the present invention is suitably used for a tread rubber of a tire. The pneumatic tire of the present invention is manufactured by a usual method using the rubber composition of the present invention. That is, if necessary, the rubber composition according to the present invention containing the various chemicals as described above is extruded into a tread member in an unvulcanized stage, and is attached by a normal method on a tire molding machine. The green tire is molded. The green tire is heated and pressed in a vulcanizer to obtain a tire. The pneumatic tire of the present invention thus obtained is excellent in handling stability especially on wet road surfaces and chunk performance in circuit running and the like.

[0019]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The performance of the tire was measured according to the following procedure. (1) Wet steering stability On a wet road surface, an actual vehicle was evaluated, and the test driver evaluated driveability, braking performance, steering wheel responsiveness, and steering controllability.
The overall evaluation was performed in consideration of the result of the stopping distance from the speed of hr. Comparative Example 1 was set to 100, and ± 5 points were added when the professional evaluation driver could recognize the difference compared to Comparative Example 1, and ± 10 points were added when the professional evaluation driver could clearly recognize the difference. displayed. The larger the value, the better the wet steering stability. (2) Chunk property The actual vehicle was evaluated on a test course, and the lack of the tread portion after 15 Laps was visually evaluated to evaluate the chunk property after running. The result of the evaluation is the result of Comparative Example 1 as 100.
And expressed as an index. The larger the numerical value, the better the chunk property (the less chipping).

Examples 1 to 6 and Comparative Examples 1 to 5 Including the components and types shown in Table 1, 3.5 parts by weight of zinc white, 3.0 parts by weight of stearic acid, antioxidant 6
C (N-1,3-dimethylbutyl-N′-phenyl-p
-Phenylenediamine) 1.0 part by weight, vulcanization accelerator DPG
(Diphenylguanidine) 0.6 parts by weight, vulcanization accelerator NS
A rubber composition containing 1.0 part by weight of (N-tert-butyl-2-benzothiazylsulfenamide) and 1.2 parts by weight of a vulcanization accelerator DM (dibenzothiazyl disulfide) was prepared. Next, a tire (205 / 50R16) provided with a tread rubber made of each of the rubber compositions was trial-produced, and the performance was evaluated at an internal pressure of 0.2 MPa. The results are shown in Table 1.

[0021]

[Table 1]

[0022]

[Table 2]

(Note) (1) SBR # 1712: manufactured by JSR Corporation, 24% by weight of styrene unit in copolymer, 18.9% by weight of vinyl binding component,
Oil content 37.5 parts by weight (based on 100 parts by weight of rubber component) (2) SBR # 0120: manufactured by JSR, 35% by weight of styrene unit in copolymer, 18.9% by weight of vinyl binding component,
Oil content 37.5 parts by weight (based on 100 parts by weight of rubber component) (3) SBR # 0540: manufactured by JSR, 34.9% by weight of styrene unit in copolymer, 42.5% by weight of vinyl binding component Oil content 60.0 parts by weight (based on 100 parts by weight of rubber component) (4) Carbon black N110: manufactured by Tokai Carbon Co., Ltd.
Seast 9 (5) Silica AQ: manufactured by Nippon Silica Co., Ltd. (6) Surface treated silica 1: silica AQ surface-treated with 5% by weight (to silica) of silicone oil (dimethyl silicone oil KF96 (manufactured by Shin-Etsu Chemical Co., Ltd.)) (7) Surface-treated silica 2: silica AQ surface-treated with 23% by weight (based on silica) of silicone oil (dimethyl silicone oil KF96 (manufactured by Shin-Etsu Chemical Co., Ltd.)) (8) Silane coupling agent: bis (3- (Ethoxysilylpropyl) tetrasulfide (9) Styrene unit content, vinyl binding component content: values in all SBR (10) Silica ratio: ratio of silica to total amount of silica and carbon black (11) Total filler amount: Total amount of carbon black and silica. (12) Total softener amount: Oil in rubber component Is the total amount of the additive softener

As can be seen from Table 1, by blending silica surface-treated with 1 to 20% by weight of silicone oil, wet steering stability can be improved without deteriorating the chunking property during running. .

[0025]

EFFECT OF THE INVENTION The rubber composition of the present invention has a reinforcing property suitable for a tread for a high-performance tire, and particularly has both a steering stability on a wet road surface (wet performance) and a chunk performance on a circuit running or the like. An improved tire can be provided.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08K 9/06 C08K 9/06

Claims (5)

[Claims] (A) a copolymer of a conjugated diene compound and a vinyl aromatic hydrocarbon compound, (B) (a) a surface treatment with 1 to 20% by weight (based on hydrous silicic acid) of an organosilicon compound, and Relational equation 0.95 ≧ BET (2) / BET (1) ≧ 0.6 1.1 ≧ PO (2) / PO (1) ≧ 0.9 300 ≧ PO (2) ≧ 100 300 ≧ BET (2) ≧ 125 (However, BET (1) and BET (2) are nitrogen adsorption specific surface area (m ² / g) of hydrated silicate before and after surface treatment, respectively, and PO (1) and PO (2) are The specific surface area (m ² / g) of the hydrous silicic acid before and after the surface treatment, respectively, of the hydrous silicic acid is 40 to 100% by weight of the surface-treated hydrous silicic acid and (b) carbon black 60 to 0%. % By weight of a reinforcing filler, and (C) a silane coupling agent, The content of the component (B) is 70 to 110 parts by weight per 100 parts by weight of the component (A), and the content of the component (C) is less than the content of the surface-treated hydrated silica of the component (B) (A). 2 to 15% by weight of a rubber composition. 2. The silane coupling agent of component (C)
General formula _{(I) A m B 3-} m Si-XS a -X-SiA m B 3-m ·· (I) ( In the formula, A _{C n H 2n + 1 O (} n is an integer of 1 to 3 ) Or a chlorine atom, B is an alkyl group having 1 to 3 carbon atoms, and X is 1 carbon atom.
To 9 saturated or unsaturated alkylene groups or 7 carbon atoms
May be an integer of 1 to 3 and may have a distribution. However, when m is 1, two B's may be the same or different, and when m is 2 or 3, two or three A's may be the same or different. Compounds represented by), the general formula _{(II) A m B 3-} m Si-XY ··· (II) ( In the formula, A _{C n H 2n + 1 O (} n is an integer of 1 to 3) or A chlorine atom, B is an alkyl group having 1 to 3 carbon atoms, X is 1 carbon atom
To 9 saturated or unsaturated alkylene groups or 7 carbon atoms
To 15 are arylene groups, Y is a mercapto group, a vinyl group,
An amino group, a glycidoxy group or an epoxy group, m is 1 to 3
Indicates an integer. However, when m is 1, two B's may be the same or different, and when m is 2 or 3, two or three A's may be the same or different. Compounds represented by), and the general formula _{(III) A m B 3-} m Si-XS a -Z ··· (III) ( In the formula, A is _{C n H 2n + 1 O (} n 1~3 ) Or a chlorine atom, B is an alkyl group having 1 to 3 carbon atoms, and X is 1 carbon atom.
To 9 saturated or unsaturated alkylene groups or 7 carbon atoms
To 15 are arylene groups, Z is a benzothiazolyl group, N,
An N-dimethylthiocarbamoyl group or a methacryloyl group, m is an integer of 1 to 3, and a is an integer of 1 or more and may have a distribution. However, when m is 1, two B's may be the same or different, and when m is 2 or 3, two or three A's may be the same or different. 2. The rubber composition according to claim 1, which is at least one selected from the compounds represented by the formula (1). 3. The rubber composition according to claim 1, wherein the total copolymer of the component (A) contains 32 to 40% by weight of a vinyl aromatic hydrocarbon compound unit and 15% by weight or more of a vinyl binding component. . 4. The rubber composition according to claim 1, further comprising (D) 35 to 60 parts by weight of a softener per 100 parts by weight of the component (A). 5. A pneumatic tire using the rubber composition according to claim 1 for a tread rubber.