JP2009007449A - Wing rubber composition and pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wing rubber composition reducing electric resistance without worsening rolling resistance, and increasing a content of a raw material derived from a resource other than petroleum. <P>SOLUTION: This wing rubber composition of the present invention contains a rubber component and polypyrrole, the rubber component contains 80 mass% or more of natural rubber component, and the polypyrrole is compounded directly in the rubber component without being carried by a carrier, and is contained at 1 pt.mass or more to 15 pts.mass or less with respect to 100 pts.mass of the rubber component. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rubber composition for a wing used for a wing portion of a pneumatic tire and a pneumatic tire.

  In order to maintain wet grip performance while reducing rolling resistance, silica is blended in the tread portion of a pneumatic tire. However, when silica is blended, the electrical resistance of the tire is increased and static electricity is accumulated in the vehicle. Therefore, there is a problem that the fuel is ignited due to the occurrence of a spark when refueling.

  In order to solve such a problem, a technique for applying rubber cement to the tread surface, a technique for embedding a low electric resistance rubber in the tread, and reducing an electric resistance between a road surface and a tire have been proposed ( For example, Patent Document 1).

  However, even if the electrical resistance in the tread portion of the pneumatic tire can be reduced by the proposal as described above, if the electrical resistance increases in the wing portion adjacent to the tread portion in the tire side surface direction, as described above. Problems may continue to occur.

  In order to solve such problems, it is conceivable to reduce the electrical resistance by adding conductive carbon black to the rubber component constituting the wing part. However, such carbon black deteriorates the rolling resistance. There is concern about making it happen.

  Further, as means for imparting conductivity to the rubber component, in addition to means for blending such carbon black, for example, a conductive material in which a conductive polymer is supported on this carrier using fibers, silica, carbon black, etc. as a carrier. Attempts have been made to blend in rubber components (Patent Documents 2 to 4). However, depending on the conductive material supported on such a carrier, the electrical resistance of the rubber component may not be sufficiently reduced.

On the other hand, in recent years, environmental issues have become more important, regulations on the suppression of carbon dioxide emissions have been strengthened, and the amount of petroleum raw materials is limited and the supply amount has been decreasing year by year. For this reason, in the manufacture of tires, it is desired to use raw materials made of non-petroleum resources that do not depend on petroleum resources, and proposals corresponding to such use have been made (for example, Patent Document 5).
Japanese Patent No. 2944908 Japanese Patent Laid-Open No. 10-036559 JP-A-10-309905 Japanese Patent Laid-Open No. 11-049892 JP 2003-063206 A

  The present invention has been made in view of the current situation as described above, and its object is to reduce the electrical resistance without deteriorating the rolling resistance and to provide a raw material originating from resources other than petroleum. It is in providing the rubber composition for wings and the pneumatic tire which raised content of.

  The rubber composition for wing of the present invention contains a rubber component and polypyrrole, the rubber component contains 80% by mass or more of a natural rubber component, and the polypyrrole is directly supported without being supported on a carrier. 1 to 15 parts by mass with respect to 100 parts by mass of the rubber component.

  Here, the natural rubber component is preferably composed of one or more components selected from the group consisting of natural rubber and modified natural rubber, and the rubber component is composed only of such a natural rubber component. Is preferred. The natural rubber component preferably has a total epoxidation rate of 0.05 to 0.65.

  Moreover, the pneumatic tire of this invention is provided with the wing part obtained using the said rubber composition for wings.

  The rubber composition for a wing of the present invention has the above-described configuration, and thus has excellent safety because electric resistance can be reduced without deteriorating rolling resistance (that is, realizing low fuel consumption). In addition, by increasing the content of raw materials originating from non-petroleum resources, the natural environment is taken into consideration in preparation for a future reduction in oil supply. In addition, the pneumatic tire of the present invention is provided with a wing part obtained by using such a rubber composition for wings, so that electric resistance can be reduced without deteriorating rolling resistance, and excellent in safety. In addition, by increasing the content of raw materials originating from non-petroleum resources, the natural environment is taken into consideration in preparation for a future reduction in oil supply.

Hereinafter, the present invention will be described in more detail.
<Rubber composition for wing>
The rubber composition for a wing of the present invention is used for a wing portion of a tire and includes a rubber component and polypyrrole. As long as these components are included, other components can be included within a range in which the effects of the present invention are exhibited.

  The wing portion referred to in the present invention is a portion adjacent to the tread portion in contact with the road surface in the tire in the tire side surface direction, a sidewall portion forming a side surface extending inward in the tire radial direction, and the tread portion. The part located between.

<Rubber component>
The rubber component contains 80% by mass or more of a natural rubber component. That is, the content of raw materials originating from non-petroleum resources is increased by containing natural rubber components that are non-petroleum resources in such a high concentration. Therefore, the higher the content of the natural rubber component, the better. Therefore, the upper limit is not specified, and it is also preferable that such a rubber component is composed only of the natural rubber component. However, as will be described later, other rubber components (for example, synthetic rubber) may be contained in an amount of 20% by mass or less. In addition, when the natural rubber component is less than 80% by mass, the effect in consideration of the natural environment as described above is poor.

<Natural rubber component>
The natural rubber component is composed of one or more components selected from the group consisting of natural rubber and modified natural rubber. That is, the natural rubber component of the present invention may contain only natural rubber, may contain only modified natural rubber, or may contain both natural rubber and modified natural rubber. In these cases, the natural rubber may be used in one or more components (that is, one kind may be used alone, or two or more kinds may be used in combination), and similarly, the modified natural rubber. 1 or 2 or more components (that is, one kind may be used alone, or two or more kinds may be used in combination). Hereinafter, each type will be described.

<Natural rubber>
Any natural rubber may be used as long as it is known as natural rubber, and the place of origin is not limited. Such natural rubber mainly contains cis 1,4 polyisoprene, but can also contain trans 1,4 polyisoprene according to required characteristics.

  Therefore, the natural rubber includes natural rubber mainly containing trans 1,4 isoprene, such as balata which is a kind of rubber of the South American Acatecaceae, in addition to natural rubber mainly containing cis 1,4 polyisoprene. It is. The natural rubber component of the present invention may contain one or more of such natural rubbers (that is, one component or two or more components).

<Modified natural rubber>
The modified natural rubber is obtained by modifying or purifying the above natural rubber. For example, epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR) and the like are included. The natural rubber component of the present invention can contain one or more of such modified natural rubbers (that is, one component or two or more components).

  Here, examples of the epoxidized natural rubber include those having an epoxidation rate of 25% (ENR25) and 50% (ENR50), but are not limited thereto. In the above, the epoxidation rate indicates a ratio (%) in which the carbon-carbon double bond in the polyisoprene skeleton is epoxidized.

  Moreover, a conventionally well-known method can be employ | adopted for the method of epoxidizing natural rubber. For example, methods such as a chlorohydrin method, a direct oxidation method, a hydrogen peroxide method, an alkyl hydroperoxide method, and a peracid method can be employed. Examples of the peracid method include a method in which natural rubber is reacted with an organic peracid such as peracetic acid or performic acid.

  The modified natural rubber may contain one or more of such epoxidized natural rubbers (that is, one component or two or more components).

<Total epoxidation rate>
The natural rubber component of the present invention preferably has a total epoxidation rate of 0.05 to 0.65. When the total epoxidation rate is less than 0.05, the rigidity, hardness, and wear resistance may be inferior, and when it exceeds 0.65, the hardness becomes excessively high and the bending fatigue resistance may decrease. More preferably, the total epoxidation rate has a lower limit of 0.1 or more and an upper limit of 0.6 or less.

Here, the total epoxidation rate in the present invention is represented by the following formula.
Total epoxidation rate = A x B / C
In the above formula, A represents the mass part of the epoxidized natural rubber contained in 100 parts by mass of the natural rubber component, B represents the epoxidation rate of the epoxidized natural rubber, and C represents 100 parts by mass (the total amount of the natural rubber component). Is 100 parts by mass).

  In the present invention, by defining the total epoxidation rate as 0.05 or more and 0.65 or less in this way, various characteristics of rubber components such as rigidity, hardness, wear resistance, and bending fatigue resistance are dramatically improved. In addition to the improvement, even if the polypyrrole is blended directly in the rubber component without supporting it on the carrier, the polypyrrole bleed does not occur. If the total epoxidation rate is out of the above range, polypyrrole will bleed, and sufficient conductivity will not be exhibited, and the rubber property itself will be deteriorated.

<Other rubber components>
The rubber component of the present invention can contain the following other rubber component (synthetic rubber) in addition to the above natural rubber component. Examples of such other rubber components include styrene butadiene rubber (SBR), butadiene rubber (BR), styrene isoprene copolymer rubber, isoprene rubber (IR), ethylene propylene diene rubber (EPDM), butyl rubber (IIR), Examples thereof include chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR), halogenated butyl rubber (X-IIR), and a halide of a copolymer of isobutylene and p-methylstyrene. Such other rubber components can be contained singly or in combination of two or more, and can be mixed with the natural rubber component in the range of 20% by mass or less. However, from the viewpoint of increasing the amount of non-petroleum resources used, the amount of such other rubber components used is preferably as small as possible.

<Polypyrrole>
The polypyrrole is blended directly into the rubber component without being supported on a carrier, and is contained in an amount of 1 to 15 parts by mass with respect to 100 parts by mass of the rubber component. As described above, in the present invention, polypyrrole is used as the conductive material, and the polypyrrole is imparted to the rubber component directly without supporting the polypyrrole on the carrier (that is, sufficient electrical resistance is provided). It has a feature in that it has been reduced. As a result, it is possible to prevent deterioration of rolling resistance, which becomes a problem when conductive carbon black is used, and to sufficiently reduce electric resistance because it is directly blended without being supported on a carrier. In addition, using polypyrrole made of bone meal or the like as a raw material contributes to an increase in the use ratio of non-petroleum resources. The effect of preventing the deterioration of rolling resistance is further improved by the combined use with the natural rubber component having the total epoxidation rate as described above, and the use of the natural rubber component having such a total epoxidation rate. This prevents bleeding from the rubber component.

  When the compounding amount of polypyrrole is less than 1 part by mass, sufficient conductivity cannot be ensured. On the other hand, when the blending amount exceeds 15 parts by mass, rolling resistance is greatly deteriorated. The amount of polypyrrole is more preferably 2 parts by mass or more, more preferably 3 parts by mass or more, and the upper limit thereof is 12 parts by mass or less, more preferably 10 parts by mass with respect to 100 parts by mass of the rubber component. It is as follows.

  In the present invention, the term “polypyrrole is directly blended in the rubber component without being supported on the carrier” means that the carrier is supported by or contains polypyrrole using, for example, fiber, silica, carbon black or the like as a carrier. Or in a state where the surface of the carrier is coated with polypyrrole (that is, such a state is referred to as a state where the carrier is supported on the carrier). It shall be compounded in the rubber component in a non-supported state (that is, in a simple substance state).

Such a polypyrrole is a homopolymer having a structural unit as pyrrole, and preferably has a weight average molecular weight (M _w ) of 100,000 or more and 300,000 or less, more preferably the lower limit thereof is 150,000 or more, The upper limit is 250,000 or less. When the weight average molecular weight is less than 100,000, the conductivity may not be exhibited. When it exceeds 300,000, the workability may be deteriorated.

  The rubber composition for wings of the present invention can contain one or more kinds of such polypyrrole.

<Other ingredients>
The rubber composition for a wing of the present invention may contain other components as long as it contains the above rubber component and polypyrrole. Examples of such other components include white fillers, silane coupling agents, vulcanizing agents (sulfur), vulcanization accelerators, vulcanization aids, crosslinking agents, crosslinking accelerators, anti-aging agents, fillers, Various conventionally known compounding agents or additives blended for tires or general rubber compositions such as waxes, softeners, plasticizers, coupling agents, etc. can be blended in conventionally known amounts.

  The rubber composition for a wing of the present invention contains a white filler (in particular, the term white is used for convenience but does not strictly define the degree of white as a color) among other components as described above. preferable. Such a white filler exhibits an action as a reinforcing agent for the rubber component, such as silica, sericite, calcium carbonate, clay, alumina, talc, magnesium carbonate, magnesium hydroxide, magnesium oxide, titanium oxide and the like. Can be mentioned. Among these white fillers, it is particularly preferable to use silica (one or two or more kinds of white fillers can be used, but silica can be used even when a white filler other than silica is used. It is preferable to use in combination. This is because the use of silica in this way makes it possible to improve each of conductivity, reinforcement, and rolling resistance in a balanced manner. In particular, the combined use of polypyrrole as a conductive substance and this silica dramatically improves the reinforcing property for the rubber component.

The BET specific surface area of such silica is preferably 100 m ² / g or more, and more preferably 125 m ² / g or more. BET specific surface area of the silica is less than 100 m ² / g, there is a tendency that the performance described above can not be sufficiently exhibited. Further, BET specific surface area of silica is preferably 250 meters ² / g or less, more preferably 210 m ² / g. When the BET specific surface area of silica exceeds 250 m ² / g, the processability tends to deteriorate.

  Such a white filler is preferably used in an amount of 5 to 80 parts by mass with respect to 100 parts by mass of the rubber component.

  Moreover, it is preferable to use the above white filler with a silane coupling agent. Thus, the reinforcement effect | action with respect to a rubber component can further be improved by using a silane coupling agent together. As such a silane coupling agent, any conventionally known silane coupling agent can be used and is not particularly limited. Examples of silane coupling agents include bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (4-triethoxysilylbutyl) tetrasulfide, and bis (3-trimethoxy Silylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (4-trimethoxysilylbutyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (2-triethoxysilylethyl) ) Trisulfide, bis (4-triethoxysilylbutyl) trisulfide, bis (3-trimethoxysilylpropyl) trisulfide, bis (2-trimethoxysilylethyl) trisulfide, bis (4-trimethoxysilylbutyl) Resulfide, 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-dimethylthiocarbamoyltetra Sulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-trimethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilyl Sulfide systems such as propylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide; 3-mercaptopropyltrimethoxy Mercapto series such as silane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane; Vinyl series such as vinyltriethoxysilane, vinyltrimethoxysilane; 3-aminopropyltriethoxy Silane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltri Amino group such as methoxysilane; glycidoxy such as γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane Nitro system such as 3-nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane; 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane, 2-chloroethyl And chloro-based compounds such as triethoxysilane. These silane coupling agents may be used alone or in combination of two or more.

  It is preferable that the compounding quantity of such a silane coupling agent shall be 1 to 20 mass% with respect to a white filler. When the compounding quantity of a silane coupling agent is less than 1 mass%, the above effects by the combined use of a silane coupling agent may not be obtained. On the other hand, even if the blending amount exceeds 20% by mass, further improvement in the effect cannot be expected, which is economically disadvantageous. Considering the dispersion effect and the coupling effect, the blending amount is more preferably 2% by mass or more and 15% by mass or less.

<Pneumatic tire>
The pneumatic tire of the present invention includes a wing portion obtained by using the above rubber composition for a wing. That is, the pneumatic tire of the present invention includes a pneumatic tire having any conventionally known structure as long as such a wing portion is provided.

  For example, as shown in FIG. 1, such a pneumatic tire 1 includes a tread portion 2 including a cap tread portion 2 a and a base tread portion 2 b, and a pair of adjacent tire tread portions 2 in the tire side surface direction. Generally, it has a structure including a wing portion 10, a sidewall portion 3 that is in contact with each wing portion 10 and extends inward in the tire radial direction, and a bead portion 4 positioned at an inner end of each sidewall portion 3. Is. A carcass 6 is bridged between the bead portions 4, and a belt layer 7 that reinforces the tread portion 2 with a tagging effect is disposed outside the carcass 6 and inside the tread portion 2. .

  The carcass 6 is formed of one or more carcass plies in which the carcass cord is arranged at an angle of, for example, 70 to 90 ° with respect to the tire equator CO. The carcass ply extends from the tread portion 2 to the sidewall portion 3. After that, the periphery of the bead core 5 of the bead portion 4 is folded back from the inner side in the tire axial direction to be locked.

  The belt layer 7 is composed of two or more belt plies in which the belt cords are arranged at an angle of, for example, 40 ° or less with respect to the tire equator CO. The belt layers 7 are stacked in different directions so that the belt cords cross each other. is doing.

  Further, a bead apex rubber 8 extending radially outward from the bead core 5 is disposed in the bead portion 4, and an inner liner rubber 9 forming a tire lumen surface is adjacent to the inside of the carcass 6. The outside of the carcass 6 is protected by clinch rubber 4G and sidewall rubber 3G.

The rubber composition for a wing of the present invention is used for the wing part 10.
The pneumatic tire of the present invention is produced by a conventionally known method using the wing rubber composition of the present invention. That is, the rubber composition for a wing having the above-described structure is kneaded, extruded in accordance with the shape of the wing portion of the tire at an unvulcanized stage, and a normal method on a tire molding machine together with other members of the tire. An unvulcanized tire is formed by molding with. The pneumatic tire of the present invention can be obtained by heating and pressurizing the unvulcanized tire in a vulcanizer.

  The pneumatic tire of the present invention is provided with a wing part obtained by using such a rubber composition for wings, so that electrical resistance can be reduced without deteriorating rolling resistance, and the safety is excellent. In addition, by increasing the content of raw materials originating from non-petroleum resources, the natural environment is taken into consideration in preparation for future reductions in oil supply.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

<Examples 1-4 and Comparative Examples 1-2>
<Preparation of rubber composition for wing>
In accordance with the formulation shown in Table 1, using a 1.7L Banbury mixer manufactured by Kobe Steel, the components other than sulfur and vulcanization accelerator NS were filled so that the filling rate would be 58%, and the rotational speed The mixture was kneaded at 80 rpm at 150 ° C. for 5 minutes. Next, sulfur and vulcanization accelerator NS were added to the obtained kneaded material in the blending amounts shown in Table 1, and then kneaded at 80 ° C. for 5 minutes using biaxial open rolls. The rubber composition for wings in the kneaded state of Comparative Examples 1 and 2 was obtained.

In Table 1, the details of various blending components used in Examples and Comparative Examples are as follows.
(1) Rubber component: 50 parts by mass of natural rubber (“KR7” manufactured by Tech Behang) and 50 parts by mass of epoxidized natural rubber (“ENR25” (epoxidation rate: 25%) manufactured by Malaysian Rubber Bureau) Rubber component consisting of. That is, the rubber component is composed of only a natural rubber component having a total epoxidation rate of 0.125 (content of natural rubber component: 100% by mass).
(2) polypyrrole: Tea er Chemical Co. (weight average molecular weight (M _W): 200000). Incorporated directly into the rubber component without being supported on a carrier.
(3) Silica: “Ultra Gil VN3” manufactured by Degussa with a BET of 210 m ² / g.
(4) Silane coupling agent: “Si266” manufactured by Degussa.
(5) Wax: “Sannokk Wax” manufactured by Ouchi Shinsei Chemical Co., Ltd.
(6) Anti-aging agent: “NOCRACK 6C” (N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine) manufactured by Ouchi Shinsei Chemical Co., Ltd.
(7) Stearic acid: manufactured by NOF Corporation. Acts as a vulcanization aid.
(8) Zinc oxide: “Zinc Hana 1” manufactured by Mitsui Mining & Smelting Co., Ltd. Acts as a vulcanization aid.
(9) Sulfur: Powdered sulfur manufactured by Tsurumi Chemical Co., Ltd.
(10) Vulcanization accelerator NS: “Noxeller NS” manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.

<Performance evaluation>
And the performance was evaluated on condition of the following using the rubber composition for wings obtained individually as mentioned above. The results are shown in Table 1.

<Evaluation of conductivity>
Using the rubber composition for a wing, a test piece having a thickness of 2 mm and a 15 cm square was prepared. And the electrical resistance (volume specific resistance value) of this test piece was measured using the electrical resistance measuring device R8340A made from ADVANTEST. The measurement conditions were a voltage of 500 V, an air temperature of 25 ° C., and a humidity of 50%. A smaller volume specific resistance value (log Ωcm) indicates a lower electrical resistance and better conductivity.

<Evaluation of rolling resistance (viscoelasticity test)>
Using the above rubber composition for wings, a test piece having a thickness of 2 mm and a 15 cm square was prepared. Then, the rolling resistance index (tan δ) of the test piece was measured using a viscoelastic spectrometer manufactured by Iwamoto Seisakusho. The measurement conditions were a frequency of 10 Hz, a dynamic strain of 2%, and a temperature of 60 ° C. The smaller the tan δ, the lower the heat generation and the lower the rolling resistance (that is, the better).

  As is apparent from Table 1 showing the results of performance evaluation, the rubber composition for wings of Examples of the present invention (that is, including a rubber component and polypyrrole, the rubber component including 80% by mass or more of a natural rubber component, Polypyrrole is blended directly into the rubber component without being supported on a carrier and contains 1 part by mass to 15 parts by mass with respect to 100 parts by mass of the rubber component). The wing rubber composition had superior electrical conductivity compared to the wing rubber composition, and also exhibited better rolling resistance than the wing rubber composition of Comparative Example 2.

  Therefore, the rubber composition for a wing of the present invention and the pneumatic tire provided with the wing portion obtained by using the rubber composition can reduce electrical resistance without deteriorating rolling resistance (that is, good rolling resistance and low electrical resistance). It is clear that the product is excellent in safety and has a higher content of raw materials originating from non-oil resources than in the composition shown in Table 1. It is clear that this is in preparation for a decrease in the supply amount.

  In the above examples, since a mixture of natural rubber and epoxidized natural rubber having the total epoxidation rate as described above was used as the rubber component of the rubber composition for wings, no bleeding of polypyrrole was confirmed. .

  Although the embodiments and examples of the present invention have been described as described above, it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments and examples.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic sectional drawing which shows an example of the pneumatic tire of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Pneumatic tire, 2 tread part, 2a cap tread part, 2b base tread part, 3 side wall part, 4 bead part, 5 bead core, 6 carcass, 7 belt layer, 8 bead apex rubber, 9 inner liner rubber, 10 Wing club.

Claims (5)

Including a rubber component and polypyrrole,
The rubber component contains 80% by mass or more of a natural rubber component,
The polypyrrole is blended directly in the rubber component without being supported on a carrier, and is contained in a rubber composition for a wing that is contained in an amount of 1 to 15 parts by mass with respect to 100 parts by mass of the rubber component. object.   2. The rubber composition for a wing according to claim 1, wherein the natural rubber component comprises one or more components selected from the group consisting of natural rubber and modified natural rubber.   The rubber composition for a wing according to claim 1 or 2, wherein the rubber component comprises only the natural rubber component.   The rubber composition for a wing according to any one of claims 1 to 3, wherein the natural rubber component has a total epoxidation rate of 0.05 to 0.65.   A pneumatic tire provided with the wing part obtained using the rubber composition for wings in any one of Claims 1-4.

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