JP2018016768A - Rubber composition and pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition which is excellent in elongation at break while maintaining low heat build-up properties and wet grip performance at a high level, and a pneumatic tire.SOLUTION: The rubber composition contains a diene rubber, at least one selected from the group consisting of carbon black and white fillers, an acid-modified polyolefin, and a coumarone-indene resin. The content of the acid-modified polyolefin is 2-30 pts.mass based on 100 pts.mass of the diene rubber. The content of the coumarone-indene resin is 0.5-30 pts.mass based on 100 pts.mass of the diene rubber.SELECTED DRAWING: Figure 1

Description

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

Conventionally, a pneumatic tire is desired to have low fuel consumption performance, grip performance, high strength, and the like.
Along with the further improvement in performance of pneumatic tires in recent years, the level required for low heat build-up, wet grip performance, vulcanized physical properties, etc., for rubber compositions used in pneumatic tires is higher than before. ing.
Under such circumstances, for example, Patent Document 1 discloses a diene rubber, an acid-modified polyolefin (A), a polyolefin for the purpose of providing a rubber composition or the like that can increase modulus while maintaining excellent low heat build-up. (B), and the acid-modified polyolefin (A): polyolefin (B) is in a mass ratio of 1: 5 to 5: 1, and the total amount of the acid-modified polyolefin (A) and the polyolefin (B) is The rubber composition which is 3-60 mass parts with respect to 100 mass parts of diene rubber is described.

Japanese Patent Laid-Open No. 2006-30800

When this inventor prepared the rubber composition with reference to patent document 1 and evaluated this, it became clear that such a rubber composition may become wet grip performance low.
Further, the present inventors have found that the rubber composition as described above may not satisfy the level required for elongation at break recently.
Accordingly, an object of the present invention is to provide a rubber composition that is excellent in elongation at break while maintaining low exothermic property and wet grip performance at a high level.
Another object of the present invention is to provide a pneumatic tire.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the rubber composition contains the acid-modified polyolefin and the coumarone indene resin in a predetermined amount, so that a desired effect can be obtained. It came.
The present invention is based on the above knowledge and the like, and specifically, solves the above problems by the following configuration.

1. Diene rubber,
At least one selected from the group consisting of carbon black and white filler;
An acid-modified polyolefin;
Containing coumarone indene resin,
The content of the acid-modified polyolefin is 2 to 30 parts by mass with respect to 100 parts by mass of the diene rubber,
The rubber composition whose content of a coumarone indene resin is 0.5-30 mass parts with respect to 100 mass parts of diene rubbers.
2. 2. The rubber composition according to 1 above, wherein the mass ratio of coumarone indene resin to acid modified polyolefin (coumarone indene resin / acid modified polyolefin) is 0.5 to 1.5.
3. 3. The rubber composition according to 1 or 2 above, wherein the coumarone indene resin has a weight average molecular weight of 500 or less.
4). 4. The rubber composition according to any one of 1 to 3 above, wherein the main skeleton of the acid-modified polyolefin is an ethylene / 1-butene copolymer.
5. The rubber composition according to any one of 1 to 4 above, wherein the carbon black content is 10 to 150 parts by mass with respect to 100 parts by mass of the diene rubber.
6). The rubber composition according to any one of 1 to 5 above, wherein the content of the white filler is 5 to 120 parts by mass with respect to 100 parts by mass of the diene rubber.
7). The pneumatic tire produced using the rubber composition in any one of said 1-6.

The rubber composition of the present invention is excellent in elongation at break while maintaining low exothermic property and wet grip performance at a high level.
The present invention can also provide a pneumatic tire.

FIG. 1 is a partial cross-sectional schematic view of a tire representing an example of an embodiment of the pneumatic tire of the present invention.

The present invention will be described in detail below.
In this specification, (meth) acryl represents acryl or methacryl.
In addition, a numerical range expressed using “to” in this specification means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In this specification, the substance applicable to each component can be used individually or in combination of 2 or more types. When a component contains two or more types of substances, the content of the component refers to the total content of the two or more types of substances.
In this specification, it may be said that the effect of the present invention is more excellent when at least one of low exothermic property, wet grip performance, and elongation at break is more excellent.

[Rubber composition]
The rubber composition of the present invention (the composition of the present invention)
Diene rubber,
At least one selected from the group consisting of carbon black and white filler;
An acid-modified polyolefin;
Containing coumarone indene resin,
The content of the acid-modified polyolefin is 2 to 30 parts by mass with respect to 100 parts by mass of the diene rubber,
It is a rubber composition whose content of the coumarone indene resin is 0.5 to 30 parts by mass with respect to 100 parts by mass of the diene rubber.

Since the composition of this invention takes such a structure, it is thought that a desired effect is acquired. The reason is not clear, but it is presumed that it is as follows.
The acid-modified polyolefin contained in the rubber composition of the present invention is modified with an acid and can interact with and effectively disperse at least one selected from the group consisting of carbon black and white filler. Therefore, it is considered that the rubber composition of the present invention is excellent in low exothermic property.
The acid-modified polyolefin and the coumarone indene resin are common in that the main skeleton is a hydrocarbon. Therefore, the acid-modified polyolefin is considered to be compatible with the coumarone indene resin. Due to the compatibility as described above, it is presumed that the coumarone indene resin recovers the decrease in wet grip performance due to the acid-modified polyolefin, and is excellent in elongation at break while maintaining low exothermic property and wet grip performance at a high level.
Hereinafter, each component contained in the composition of this invention is explained in full detail.

<Diene rubber>
The diene rubber contained in the rubber composition of the present invention is not particularly limited. Examples of the diene rubber include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), aromatic vinyl-conjugated diene copolymer rubber, chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR), and ethylene. -Propylene-diene copolymer rubber (EPDM), styrene-isoprene rubber, isoprene-butadiene rubber, nitrile rubber, hydrogenated nitrile rubber and the like.
The diene rubbers can be used alone or in combination of two or more.
Of these, aromatic vinyl-conjugated diene copolymer rubber, NR, and BR are preferable.
Examples of the aromatic vinyl-conjugated diene copolymer rubber include styrene butadiene rubber (SBR) and styrene isoprene rubber. Of these, SBR is preferable.

  Although the weight average molecular weight of a diene rubber is not specifically limited, From a workability viewpoint, it is preferable that it is 50,000-3,000,000, and 100,000-2,000,000 is more preferable. The weight average molecular weight (Mw) of the diene rubber is a standard polystyrene equivalent value based on a value measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent.

  When the diene rubber contains an aromatic vinyl-conjugated diene copolymer rubber and BR, the content of the aromatic vinyl-conjugated diene copolymer rubber is the total amount of the aromatic vinyl-conjugated diene copolymer rubber and BR. 15 to 80% by mass is preferable, and 20 to 80% by mass is more preferable.

<At least one selected from the group consisting of carbon black and white filler>
The rubber composition of the present invention contains at least one selected from the group consisting of carbon black and white filler. The rubber composition of the present invention can contain at least one selected from the group consisting of carbon black and white filler as a filler. The rubber composition of the present invention preferably contains carbon black and a white filler from the viewpoint of excellent toughness and low heat build-up.

(Carbon black)
Carbon black is not particularly limited. For example, the thing similar to the carbon black which can generally be used for a rubber composition is mentioned. Specifically, for example,
SAF (Super Ablation Furnace) carbon black,
ISAF (Intermediate Super Absorption Furnace) carbon black,
IISAFISAF (Intermediate Intermediate Super Ablation Furnace) carbon black,
HAF (High Ablation Furnace) carbon black,
FEF (Fast Extracting Furnace) carbon black,
GPF (General Purpose Furnace) carbon black,
Examples thereof include SRF (Semi-Reinforcing Furnace) carbon black. Of these, SAF, ISAF, IISAF, N339, HAF, and FEF are preferable.

The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is preferably 30 to 250 m ² / g, more preferably 40 to 240 m ² / g, from the viewpoint of excellent processability of the rubber composition.
Here, N ₂ SA is a value obtained by measuring the amount of nitrogen adsorbed on the carbon black surface in accordance with JIS K 6217-2: 2001 “Part 2: Determination of specific surface area—nitrogen adsorption method—single point method”. .

(Carbon black content)
When the rubber composition of the present invention contains carbon black, the carbon black content is 10 to 150 parts by mass with respect to 100 parts by mass of the diene rubber from the viewpoint of excellent toughness and low heat build-up. Is preferable, and 15-130 mass parts is more preferable.

(White filler)
The white filler is not particularly limited. For example, the thing similar to what can generally be used for a rubber composition is mentioned. Specific examples include silica, calcium carbonate, talc, mica and the like. Of these, silica is preferable.

Silica Examples of silica include wet silica, fumed silica, calcined silica, precipitated silica, pulverized silica, fused silica, and colloidal silica.

Silica, from the viewpoint of suppressing aggregation of the silica, CTAB adsorption specific surface area of preferably ^{50~300m 2 / g, 80~250m 2 /} g is more preferable.
Here, the CTAB adsorption specific surface area was determined by measuring the adsorption amount of n-hexadecyltrimethylammonium bromide on the silica surface according to JIS K6217-3: 2001 “Part 3: Determination of specific surface area—CTAB adsorption method”. Value.

(Content of white filler)
When the rubber composition of the present invention contains a white filler, the content of the white filler is 5 to 120 mass with respect to 100 parts by mass of the diene rubber from the viewpoint of being excellent in low heat build-up and wet grip performance. Part is preferable, and 10 to 120 parts by mass is more preferable.

<Acid-modified polyolefin>
The acid-modified polyolefin contained in the rubber composition of the present invention is an acid-modified polyolefin. The acid-modified polyolefin may have a polyolefin main skeleton and an acid-modified group.

(Main skeleton of acid-modified polyolefin)
Examples of the main skeleton of the acid-modified polyolefin include a polymer having a repeating unit of at least one selected from the group consisting of ethylene and α-olefin.
The main skeleton of the acid-modified polyolefin may be either a homopolymer or a copolymer. The main skeleton of the acid-modified polyolefin is exemplified as one of preferred embodiments of a copolymer, and a copolymer of ethylene and an α-olefin is more preferred.

The α-olefin that can constitute the acid-modified polyolefin is not particularly limited as long as it is a hydrocarbon compound having an unsaturated bond at the terminal. In the present invention, the α-olefin does not contain ethylene. One preferred embodiment is that the α-olefin is composed only of carbon atoms and hydrogen atoms.
The α-olefin is preferably at least one selected from the group consisting of propylene, 1-butene and 1-octene, for example.

  A copolymer of ethylene and 1-butene (ethylene / 1-butene copolymer) is preferable from the viewpoint that the main skeleton of the acid-modified polyolefin is excellent due to low heat build-up.

(Modified group)
The modifying group that the acid-modified polyolefin can have is not particularly limited as long as it is a carboxy group or an acid anhydride group.

One preferred embodiment is that the modifying group is formed by an unsaturated carboxylic acid.
Examples of unsaturated carboxylic acids include unsaturated aliphatic carboxylic acids such as maleic acid, fumaric acid, (meth) acrylic acid, crotonic acid, and itaconic acid; and acid anhydrides thereof.
Of these, maleic anhydride, maleic acid, and acrylic acid are preferred.

Examples of the modifying group include a group represented by the following formula (1).
In formula (1), * represents a bonding point.

  The modifying group can be bonded to the main skeleton directly or via an organic group. The organic group is not particularly limited.

  One preferred embodiment of the acid-modified polyolefin has a modifying group in the side chain.

  The acid-modified polyolefin is preferably a polyolefin modified with maleic anhydride in that the effect of the present invention is more excellent and the dispersion of the filler is excellent. An ethylene / 1-butene copolymer modified with maleic anhydride is preferable. More preferred.

The melt mass flow rate (MFR) of the acid-modified polyolefin is preferably from 0.1 to 10 g / 10 min, more preferably from 0.2 to 8 g / 10 min, in that the effects of the present invention are more excellent and the processability is excellent. .
In the present invention, the MFR of the acid-modified polyolefin was measured under conditions of 230 ° C. and a load of 2.16 kg with a capillary rheometer according to ASTM D1238.

(Content of acid-modified polyolefin)
In the present invention, the content of the acid-modified polyolefin is 2 to 30 parts by mass with respect to 100 parts by mass of the diene rubber. The content of the acid-modified polyolefin is preferably 5 to 20 parts by mass and more preferably 7.5 to 15 parts by mass with respect to 100 parts by mass of the diene rubber from the viewpoint that the effect of the present invention is excellent and the processability is excellent. preferable.

<Coumarone indene resin>
The coumarone indene resin contained in the rubber composition of the present invention is not particularly limited as long as it is a polymer having repeating units of coumarone and indene.
The coumarone indene resin can further have a repeating unit other than the above repeating unit. Examples of the repeating unit other than the repeating unit include at least one repeating unit selected from the group consisting of styrene, α-methylstyrene, methylindene, and vinyl sulene.

(Weight average molecular weight of coumarone indene resin)
The weight average molecular weight of the coumarone indene resin is preferably 500 or less, and more preferably 100 to 300, from the viewpoint that the effect of the present invention is excellent and the processability is excellent. In the present invention, the weight average molecular weight of the coumarone indene resin is a standard polystyrene equivalent value based on a value measured by gel permeation chromatography (GPC) using THF (tetrahydrofuran) as a solvent.

  The coumarone indene resin is preferably liquid at room temperature.

  One preferred embodiment is that the coumarone indene resin is not modified with phenol or the like.

(Coumaron indene resin content)
In the present invention, the content of the coumarone indene resin is 0.5 to 30 parts by mass with respect to 100 parts by mass of the diene rubber. The content of the coumarone indene resin is preferably 2.5 to 15 parts by mass, and 5 to 15 parts by mass with respect to 100 parts by mass of the diene rubber from the viewpoint that the effect of the present invention is excellent and the processability is excellent. More preferred.

(Mass ratio of coumarone indene resin / acid-modified polyolefin)
The mass ratio of coumarone indene resin to acid-modified polyolefin (coumarone indene resin / acid-modified polyolefin) is excellent due to the effects of the present invention (particularly elongation at break), and has a low exothermic property, wet grip performance and elongation at break. From the viewpoint of excellent and workability, it can be set to 0.1 to 2.0, preferably 0.5 to 1.5, more preferably 0.6 to 1.5, and 0.8 to 1. 2 is more preferable.

  The composition of the present invention may further contain an additive as necessary within a range not impairing the object or effect of the present invention. Examples of additives include rubbers other than diene rubbers, fillers other than carbon black and white fillers, polyolefins other than acid-modified polyolefins, resins other than coumarone indene resins, surface lubricants, leveling agents, antioxidants, Anti-aging agent, light stabilizer, UV absorber, polymerization inhibitor, silane coupling agent, vulcanizing agent, crosslinking agent, vulcanization accelerator, vulcanization accelerator such as zinc oxide and stearic acid, vulcanization delay Examples thereof include those that can be generally blended in rubber compositions such as agents, oils and plasticizers. The kind and content of the additive can be appropriately selected.

-Silane coupling agent It is preferable that the rubber composition of this invention contains a silane coupling agent from a viewpoint that the effect of this invention is more excellent.
The silane coupling agent is not particularly limited. Among these, a silane coupling agent having a sulfur atom (a sulfur-containing silane coupling agent) is mentioned as one of preferred embodiments.
The sulfur-containing silane coupling agent is not particularly limited as long as it is a silane coupling agent having a sulfur atom. For example, polysulfide silane cups such as bis (3-triethoxysilylpropyl) tetrasulfide (Si69 manufactured by Evonik Degussa), 3-trimethoxysilylpropylbenzothiazole tetrasulfide, bis (3-triethoxysilylpropyl) disulfide Ringing agent: γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, 3- [ethoxybis (3,6,9,12,15-pentaoxaoctacosan-1-yloxy) silyl] -1-propanethiol Mercapto silane coupling agent such as (Evonik Degussa Si363); Thiocarboxylate silane coupling agent such as 3-octanoylthiopropyltriethoxysilane; 3-thiocyanate propyltri Examples include thiocyanate silane coupling agents such as ethoxysilane.
Of these, polysulfide silane coupling agents are preferable, and bis (3-triethoxysilylpropyl) tetrasulfide and bis (3-triethoxysilylpropyl) disulfide are more preferable.
The silane coupling agents can be used alone or in combination of two or more.
As the silane coupling agent, one obtained by condensing one or more of the above silane coupling agents in advance may be used. The method for condensing the silane coupling agent is not particularly limited. For example, a conventionally well-known thing is mentioned.

  In this invention, 1-30 mass parts is preferable with respect to 100 mass parts of diene rubbers, and, as for content of a silane coupling agent, the effect of this invention is more excellent, and 1-25 mass parts is more preferable.

(Method for producing rubber composition)
The manufacturing method of the rubber composition of the present invention is not particularly limited. For example, diene rubber, predetermined filler, acid-modified polyethylene, coumarone indene resin and additives that can be used as needed (excluding vulcanized components) are mixed at 100 to 170 ° C. Next, a rubber composition of the present invention can be produced by adding a vulcanization system component (for example, sulfur, a vulcanization accelerator, etc.) to the above mixture and mixing at 60 to 120 ° C. it can.

  The rubber composition of the present invention can be vulcanized or crosslinked under, for example, conventionally known vulcanization or crosslinking conditions.

The rubber composition of the present invention can be used, for example, for a pneumatic tire.
[Pneumatic tire]
Next, the pneumatic tire of the present invention will be described.
The pneumatic tire of the present invention is a pneumatic tire produced using the rubber composition of the present invention described above.
The rubber composition used for the pneumatic tire of the present invention is not particularly limited as long as it is the rubber composition of the present invention.

The rubber composition can be used for a structural member constituting a pneumatic tire.
Examples of the structural member include a tire tread portion, a sidewall portion, a bead portion, a carcass layer, and a belt layer.

  Among these, the tire tread portion is preferably formed of the rubber composition of the present invention, and at least one selected from the group consisting of a cap tread and an undertread is more preferably formed of the rubber composition of the present invention. A tread is more preferable.

In FIG. 1, the partial cross-sectional schematic of the tire showing an example of the embodiment of the pneumatic tire of this invention is shown. The present invention is not limited to the attached drawings.
In FIG. 1, the pneumatic tire has a bead portion 1, a sidewall portion 2, and a tire tread portion 3. Between the pair of left and right bead portions 1, a carcass layer 4 in which fiber cords are embedded is mounted, and an end portion of the carcass layer 4 is folded around the bead core 5 and the bead filler 6 from the inside to the outside of the tire. Rolled up. In the tire tread portion 3, a belt layer 7 is disposed over the circumference of the tire outside the carcass layer 4. In the bead portion 1, a rim cushion 8 is disposed at a portion in contact with the rim.

  The pneumatic tire of the present invention can be manufactured, for example, according to a conventionally known method. Moreover, as gas with which a tire is filled, inert gas, such as nitrogen, argon, helium other than the air which adjusted normal or oxygen partial pressure, for example, can be used.

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these.
<Manufacture of rubber composition>
A rubber composition was produced using the components shown in Table 1 below in the compositions (parts by mass) shown in the same table.
Specifically, first, components other than the vulcanization system components (sulfur and vulcanization accelerator) among the components shown in the following table were mixed with a tangential mixer at 150 ° C. to obtain a mixture. Next, a vulcanization system component was added to the said mixture, and these were mixed with the open roll on 60 degreeC conditions, and the rubber composition was manufactured.

<Evaluation>
The following evaluation was performed using the rubber composition produced as described above. The results are shown in Table 1. The evaluation results were expressed as an index with the value of the standard example as 100.

(Preparation of vulcanized rubber test piece)
The rubber composition produced as described above was press vulcanized at 160 ° C. for 20 minutes in a predetermined mold to prepare a vulcanized rubber test piece.

・ Elongation at cutting A JIS No. 3 dumbbell-shaped test piece was punched out from the vulcanized rubber test piece prepared as described above, and a tensile test at a tensile speed of 500 mm / min was performed at 25 ° C. in accordance with JIS K6251: 2010. The elongation at break (%) was measured.

・ Tanδ (0 ℃)
The vulcanized rubber test piece prepared as described above was subjected to tan δ (0 ° C.) using a viscoelastic spectrometer (manufactured by Iwamoto Seisakusho Co., Ltd.) under the conditions of an elongation deformation strain rate of 10 ± 2%, a frequency of 20 Hz, and a temperature of 0 ° C. ) Was measured.
A larger index of tan δ (0 ° C.) means better wet grip performance.

・ Tanδ (60 ℃)
The vulcanized rubber test piece prepared as described above was subjected to tan δ (60 ° C.) using a viscoelastic spectrometer (manufactured by Iwamoto Seisakusho Co., Ltd.) under the conditions of an elongation deformation strain rate of 10 ± 2%, a frequency of 20 Hz, and a temperature of 60 ° C. ) Was measured.
The smaller the index of tan δ (60 ° C.), the lower the exothermic property.

Details of each component shown in Table 1 are as follows.
SBR: Styrene butadiene rubber, Toughden E581 (oil exhibition product), manufactured by Asahi Kasei Chemicals Corporation. In Table 1, the upper value of the SBR is the amount of the oil extended product, and the value in the lower parenthesis is the net amount of SBR in 110 parts by mass of the oil extended product.
-BR: Butadiene rubber, Nippon Zeon Corporation Nipol BR 1220

  Acid-modified polyolefin 1: Maleic anhydride-modified ethylene / 1-butene copolymer (Tuffmer MH7020, manufactured by Mitsui Chemicals). It has a modifying group with maleic anhydride in the side chain. MFR 1.5 g / 10 min.

  Coumarone indene resin 1: Novales C10 manufactured by Rutgers, weight average molecular weight 150, softening point 5 to 15 ° C., liquid at room temperature

White filler (silica): Zeosil (R) 165G, Solvay S. A. Made by company. CTAB adsorption specific surface area 160m ² / g
・ Carbon black: Show black N339, N ₂ SA81m ² / g, manufactured by Cabot Japan, HAF

・ Zinc oxide: Zinc Hua No. 3 manufactured by Shodo Chemical Co., Ltd. ・ Stearic acid: Stearic acid manufactured by NOF Corporation ・ Anti-aging agent: Antigen 6C (S-13) manufactured by Sumitomo Chemical Co., Ltd.
Silane coupling agent: bis (triethoxysilylpropyl) tetrasulfide. Sulfide silane coupling agent, Si69 made by Evonik

・ Sulfur: Sulfur treatment sulfur manufactured by Karuizawa Refinery ・ Vulcanization accelerator 1: Noxeller manufactured by Ouchi Shinsei Chemical Co., Ltd. ・ Vulcanization accelerator 2: Soxinol DG manufactured by Sumitomo Chemical Co., Ltd.

As is clear from the results shown in Table 1, Comparative Examples 1 and 5 not containing coumarone indene resin had poor elongation at break and wet grip performance.
Comparative Examples 2 to 4 and 6 to 8 containing no acid-modified polyolefin were poor in elongation at break and low exothermic property.

On the other hand, the composition of the present invention was excellent in elongation at break while maintaining low exothermic property and wet grip performance at a high level.
When the coumarone indene resin / acid-modified polyolefin was 0.5 to 1.5, the elongation at break was more excellent.

1 Bead part 2 Side wall part 3 Tire tread part 4 Carcass layer 5 Bead core 6 Bead filler 7 Belt layer 8 Rim cushion

Claims (7)

Diene rubber,
At least one selected from the group consisting of carbon black and white filler;
An acid-modified polyolefin;
Containing coumarone indene resin,
The content of the acid-modified polyolefin is 2 to 30 parts by mass with respect to 100 parts by mass of the diene rubber,
The rubber composition whose content of the said coumarone indene resin is 0.5-30 mass parts with respect to 100 mass parts of said diene rubbers.   The rubber composition according to claim 1, wherein a mass ratio of the coumarone indene resin to the acid-modified polyolefin (coumarone indene resin / acid-modified polyolefin) is 0.5 to 1.5.   The rubber composition according to claim 1 or 2, wherein the coumarone indene resin has a weight average molecular weight of 500 or less.   The rubber composition according to any one of claims 1 to 3, wherein a main skeleton of the acid-modified polyolefin is an ethylene / 1-butene copolymer.   The rubber composition according to any one of claims 1 to 4, wherein a content of the carbon black is 10 to 150 parts by mass with respect to 100 parts by mass of the diene rubber.   The rubber composition according to any one of claims 1 to 5, wherein a content of the white filler is 5 to 120 parts by mass with respect to 100 parts by mass of the diene rubber.   The pneumatic tire produced using the rubber composition of any one of Claims 1-6.