JP2008296814A - Pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire capable of enhancing operation stability without impairing other tire characteristics such as ride comfort, road noise and rolling resistance while maintaining an air-retaining property. <P>SOLUTION: In the pneumatic tire 1, the pneumatic tire in which inner liners 13, 14 different at left and right sides in an axial direction of the tire are arranged is attached so as to position the right side of the tire 1 at both outer sides of the vehicle. Tensile modulus in a tire circumferential direction of the right side inner liner 13 is larger than the tensile modulus in a tire axial direction, and the tensile modulus in the tire axial direction of the left side inner liner 14 is made larger than the tensile modulus in the tire circumferential direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire capable of improving steering stability without impairing other tire characteristics such as riding comfort, road noise, and rolling resistance.

  For pneumatic tires, there is a need for both tire handling characteristics such as handling stability essential for safe driving, comfortable riding comfort, and reduction of road noise.

  In order to improve steering stability, measures were taken to reduce the belt cord angle of the belt layer, increase the rubber hardness of the tread and sidewalls, and increase the tread rigidity and side rigidity, but high SA (slip angle) )), The tire characteristics deteriorated and the road noise worsened, and it was difficult to balance each characteristic in a balanced manner.

  Conventionally, the inner liner of a pneumatic tire is a rubber liner obtained by rolling such as a calendar, and the rolling direction (roll alignment direction) is arranged in the tire circumferential direction from the viewpoint of tire molding workability. It only secured the air retention of the tire, and did not contribute to tire performance such as ride comfort, road noise and steering stability.

  For example, as a conventional example that acts from the inner surface of the tire to reduce road noise, a peak noise of road noise generated in the vicinity of 260 Nz is provided by disposing a foam rubber layer having a relatively low foaming rate on the inner cavity surface of the inner liner. It is described that noise is made uniform at each frequency by reducing the noise (Patent Document 1).

In addition, a short fiber reinforcing layer oriented in the tire axial direction is disposed between the carcass and the inner liner of the shoulder and sidewall regions to reduce rolling resistance (Patent Document 2) and to the tire lumen surface in the tire circumferential direction. It is described that a reinforcing sheet having a stiffness of 11 to 220 N / 10 mm and a tensile stiffness in the tire axial direction of 11 to 130 N / 10 mm is arranged to improve steering stability (Patent Document 3).
JP-A-6-40206 JP-A-9-150610 JP 2006-151328 A

  The technique described in Patent Document 1 improves road noise by a foamed rubber layer added to the inner liner, and the inner liner does not directly contribute to road noise. The techniques of Patent Documents 2 and 3 improve the rolling resistance and steering stability by arranging a reinforcing layer having anisotropy in orientation and modulus on the inner liner adjacent layer on the tire inner surface. The inner liner itself is related to tire characteristics such as ride comfort, road noise and steering stability, and there has been no technical example directly mentioned to improve it.

  The present invention has been made in view of the above circumstances, and by improving the inner liner of a pneumatic tire, other tire characteristics such as ride comfort, road noise, and rolling resistance are maintained while maintaining air retention. An object of the present invention is to provide a pneumatic tire capable of improving steering stability without loss.

  As a result of intensive studies on the inner liner of the tire inner surface in order to solve the above problems, the inventor has given anisotropy to the modulus of the inner liner in the tire circumferential direction and the tire axial direction, and the tire circumference on the tire circumference. By placing inner liners with specific anisotropy on the left and right inner liners, the side part rigidity can be maintained at a high level from the tire inner surface, and steering stability can be improved without impairing other tire characteristics The present invention has been reached.

  That is, according to the first aspect of the present invention, when a pneumatic tire having different inner liners arranged on the left and right in the axial direction of the tire is mounted on the vehicle, the right side of the tire is mounted on both outer sides of the vehicle. In the pneumatic tire, the right inner liner has a larger tensile modulus in the tire circumferential direction than the tensile modulus in the tire axial direction, and the left inner liner has a larger tensile modulus in the tire axial direction than the tensile modulus in the tire circumferential direction. It is a pneumatic tire.

  According to a second aspect of the present invention, the right inner liner has a ratio (E′p /) of a dynamic elastic modulus E′p along the tire circumferential direction and a dynamic elastic modulus E′r along the tire axial direction. E′r) is 1.1 or more, and the left inner liner has a ratio of a dynamic elastic modulus E′r along the tire axial direction and a dynamic elastic modulus E′p along the tire circumferential direction ( The pneumatic tire according to claim 1, wherein E'r / E'p) is 1.1 or more.

  According to a third aspect of the invention, the right inner liner is made of an inner liner rubber having orientation in the tire circumferential direction, and the left inner liner is made of an inner liner rubber having orientation in the tire axial direction. The pneumatic tire according to claim 1 or 2, characterized in that.

  The invention according to claim 4 is characterized in that the left and right inner liners are divided into left and right on the tire circumference with the tread region of the tire as a boundary. This is a pneumatic tire.

  According to the pneumatic tire of the present invention, a tire in which inner liners having a specific anisotropy are arranged on the inner liners on the left and right sides in the tire circumferential direction, while maintaining air retention by specifying the mounting position, Steering stability can be improved without impairing other tire characteristics such as comfort, road noise, and rolling resistance, and without increasing tire weight or manufacturing man-hours.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is a half sectional view of a pneumatic tire 1 according to the present invention, and FIG. 2 is an explanatory view showing a lumen portion of the tire 1.

  FIG. 3 shows a mounting position when the pneumatic tire 1 of the present invention is mounted on the vehicle. The right side of the tire 1 is mounted on both outer sides of the vehicle, and the left side of the tire 1 is mounted on the vehicle. Install on both sides.

  The pneumatic tire 1 is composed of a single carcass ply using organic fiber cords such as polyester and rayon that are folded and locked around the bead cores 5 embedded in the pair of bead portions 4 from the inside to the outside. The carcass 6, the tread portion 2 positioned on the outer periphery of the crown portion of the carcass 6, the sidewall portion 3 positioned on the side portion of the carcass 6, and the carcass 6 inside the tread rubber of the tread portion 2. A cap 7 comprising a belt 7 comprising two belt plies using a rigid cord such as a steel cord or an aramid fiber, and a nylon cord spirally wound around the outer circumference of the belt 7 in the tire axial direction. 8 and an inner liner 10 is provided on the inner surface side of the tire. The example shown in the figure shows an example of a radial tire for a passenger car provided with 1 ply of waste, 2 plies of belt, and 1 layer of cap ply, but the tire of the present invention is not limited to the above structure.

  The inner liner 10 is disposed so as to cover the tread portion 2, the sidewall portion 3, and the bead portion 4 on the tire inner peripheral surface, and retains the air pressure of the tire 1 when the tire 1 is incorporated in the rim and filled with the internal pressure. It is.

  The inner liner 10 is usually rolled into a sheet having a predetermined thickness and width by a calender device having 2 to 4 rolls for rolling rubber, and the inner liner 10 is rolled on a tire molding machine. In general, a green tire is molded by arranging the rolling direction along the tire circumferential direction on the inner circumferential surface of the tire.

  The inner liner has a crystalline state in which a rubber component blended in the rubber composition, a reinforcing agent such as carbon black, silica and calcium carbonate, a compound such as zinc white, stearic acid and petroleum resins are crystallized by the above rolling process ( Oriented in the roll alignment direction regardless of the solid state) or the amorphous state. As a result, anisotropy is exhibited in the characteristics in the direction of the inner liner and the direction perpendicular thereto.

  In other words, the properties such as tensile strength, elongation, and modulus differ between the orientation direction of the inner liner and the direction perpendicular thereto, and the properties such as the tensile modulus and strength related to the rigidity of the inner liner are particularly high in the orientation direction. Will be shown.

  The present invention pays attention to the anisotropy of the inner liner, and by arranging the rolling (orientation) direction of the inner liner along the tire circumferential direction or the axial direction, the inner liner arranged on the tire inner surface is a tire. This is due to the fact that there is anisotropy in characteristics between the circumferential direction and the axial direction, that is, the fact that the rigidity of the tensile modulus and the like is in the tire circumferential direction> the tire axial direction due to the orientation of the inner liner.

  Therefore, by arranging the high modulus direction of the inner liner 10 in the circumferential direction of the tire 1, the rigidity in the tire circumferential direction of the side portion 3 from the tire inner surface can be maintained higher than the axial direction. By increasing the rigidity in the circumferential direction of the side portion of the tire 1, it is possible to improve steering stability such as steering response, straightness, lane change, and handling during cornering.

  However, when the inner liner 10 having a high modulus in the tire circumferential direction is disposed on the entire inner liner 10 and the tire circumferential direction and the axial direction have anisotropy, the effect of improving the steering stability is high. Although it can be obtained, the road noise and riding comfort deteriorate due to increased rigidity.

  The present invention that eliminates the above-mentioned contradiction event is a pneumatic tire in which different inner liners 13 and 14 are arranged on the left and right in the circumferential direction of the tire 1. The right inner liner 13 has a tensile modulus in the tire circumferential direction P larger than the tensile modulus in the tire axial direction R, and the left inner liner 14 has a tensile modulus in the tire circumferential direction P larger than the tensile modulus in the tire axial direction R. Is done.

  That is, the tire 1 has inner liners 13 and 14 that are divided into left and right in the tire circumferential direction along the axial direction of the tire 1 with an arbitrary axial position of the tread portion 2 as a boundary. The inner liner 13 located at 11 has orientation in the tire circumferential direction (P direction), and the inner liner 14 on the tire left side 12 can be easily obtained by having orientation in the tire axial direction (R direction). it can.

  As a result, on the right side 11 in the tire circumferential direction, the inner liner 13 is made to have a high modulus in the tire circumferential direction, so that the side portion 31 has high rigidity in the tire circumferential direction and the steering stability is improved.

  On the other hand, the inner liner 14 on the left side of the tire 12 has a high modulus in the tire axial direction, so that the side portion 32 has a high rigidity in the tire axial direction.

  That is, the tire 1 has an inner liner rubber with orientation provided on the tire right side 11 in the tire circumferential direction, and the inner liner rubber with orientation on the tire left side 12 with the orientation direction in the tire axial direction. You can distribute it. Therefore, the tire 1 maintains air retention, improves driving stability without impairing other tire characteristics such as ride comfort, road noise, and rolling resistance, and does not increase the tire weight and increase the number of manufacturing steps. The present invention can be accomplished with a minimum.

  In carrying out the present invention, when the tire 1 is mounted on the vehicle, the right side of the tire is mounted on both outer sides of the vehicle, and the left side of the tire is mounted on both inner sides of the vehicle. It is a premise to do.

  Further, in the present invention, as an index of the difference (anisotropy) in modulus between the tire circumferential direction and the axial direction of the inner liner 13, the dynamic measurement measured along the calender rolling direction using the inner liner rubber as a sample. The modulus difference is quantified by the ratio E′p / E′r or E′r / E′p between the elastic modulus E′p and the dynamic elastic modulus E′r measured along the direction perpendicular to the rolling direction. be able to.

  The inner liner 13 disposed on the right side 11 of the tire 1 has a high modulus direction disposed in the tire circumferential direction, and its E′p / E′r is preferably 1.1 or more, and is disposed on the tire left side 12. The inner liner 14 has a high modulus direction in the tire axial direction, and its E′r / E′p is preferably 1.1 or more. Within this range, the effects of the present invention can be further improved.

  When E'p / E'r or E'r / E'p of the inner liners 13 and 14 is 1.1 or more, a significant difference is obtained in the tensile modulus between the tire circumferential direction and the axial direction. The tire circumferential direction or axial direction of 32 can be made high modulus, and the riding comfort can be improved without impairing the other tire characteristics.

  When E'p / E'r or E'r / E'p of the inner liners 13 and 14 is less than 1.1, the effect of improving the ride comfort cannot be obtained sufficiently, and the functions on the left and right sides of the tire are reduced. It cancels out balanced effects that maintain cancellation, road noise, and ride comfort.

  The upper limit of E′p / E′r or E′r / E′p of the inner liners 13 and 14 is not particularly limited, but is preferably 1.30 or less, more preferably 1.25 or less. Outside this preferred range, the difference in rigidity between the left and right tires becomes large, and the left and right characteristics of the tire become unbalanced, which may reduce tire characteristics such as occurrence of uneven wear and steering stability.

  In the present invention, the rubber composition used for the inner liners 13 and 14 can be a conventional rubber compound for a conventional inner liner.

  As the rubber composition of this normal blend, for example, 40 parts by weight or more of butyl rubber (IIR) and / or halogenated butyl rubber (X-IIR) having a small gas permeability coefficient as a rubber component and a diene rubber are used. Examples of the circumferential direction -IIR include chlorinated butyl rubber and brominated butyl rubber. IIR alone has drawbacks such as poor adhesion between the adjacent rubber such as the bead part and carcass and the inner liner, and slow vulcanization speed. From the viewpoint of improving these, use of X-IIR is preferable, It is also possible to blend IIR and X-IIR in any ratio.

  The IIR and / or circumferential direction-IIR is required to be contained in at least 40 parts by weight or more in 100 parts by weight of the rubber component from the viewpoint of air retention, and is preferably 50 parts by weight or more. In addition, when content of IIR and / or circumferential direction-IIR exceeds 90 weight part of a rubber component, it exists in the tendency for the adhesiveness with adjacent rubber | gum and the workability of a rubber composition to fall.

  Examples of the diene rubber include natural rubber (NR), isoprene rubber (IR), styrene butadiene rubber (SBR), butadiene rubber (BR), and styrene isoprene butadiene rubber (SIBR), which are selected from these groups. At least one of these can be used. In particular, NR, IR, and BR are preferable because they are effective in improving the adhesiveness and vulcanization rate of IIR and X-IIR.

  In the rubber composition for an inner liner according to the present invention, the rubber component and a compounding agent usually used in the rubber composition for an inner liner, for example, carbon black, silica, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide , Reinforcing agents such as alumina, clay, talc and magnesium oxide, plasticizers such as oil, cross-linking agents such as stearic acid, petroleum resins, sulfur and zinc white, cross-linking aids, vulcanization accelerators, etc. Can do.

There is no restriction | limiting in particular as a kind of said carbon black, For example, HAF, ISAF, SAF, GPF, FEF etc. are mentioned. Among them, those having a nitrogen adsorption specific surface area (N ₂ SA) of 20 to 80 m ² / g, preferably 25 to 50 m ² / g are desirable. The compounding amount of carbon black is preferably 20 to 80 parts by weight with respect to 100 parts by weight of the rubber component. When the blending amount of carbon black is less than 20 parts by weight, the reinforcing effect tends to be small, and when it exceeds 80 parts by weight, the rubber viscosity increases, and the workability during kneading or rolling tends to decrease.

  The rubber composition can be obtained by kneading using a normal rubber kneading apparatus such as a roll, a Banbury mixer, a kneader or the like.

  In addition, the orientation (dynamic elastic modulus ratio E′p / E′r) imparted to the inner liners 13 and 14 by rolling the rubber composition is adjusted by a roll arrangement (for example, 3 In this roll, it can be carried out according to the series and L type, roll rotation speed ratio, roll temperature, rolling number, and the like.

  When the desired modulus ratio (E′p / E′r = 1.1 or more) cannot be obtained in the rolling direction and the direction perpendicular thereto by adjusting the orientation of the inner liners 13 and 14 by adjusting the conditions of the rolling process. Can appropriately mix an orientation compounding agent in the rubber compounding, and adjust the modulus ratio in combination with the rolling conditions.

  The orientation compounding agent is not particularly limited. For example, crystalline thermoplastic elastomers such as syndiotactic-1,2-polybutadiene (syn-1,2-PB), short fibers such as nylon and cellulose, Examples include layered or plate-like minerals such as kaolin clay or sericite clay, and crystalline organic resins, and also include inorganic fillers such as carbon black, silica, calcium carbonate, magnesium carbonate, and aluminum hydroxide. The amount may be increased without departing from the object of the present invention.

  For example, syn-1,2-PB is preferably dispersed in the rubber composition and has an effect of increasing the rigidity of the rubber composition. As a compounding quantity, it is about 0.3-5.0 weight part as a syn-1, 2-PB part with respect to 100 weight part of rubber components. A commercially available product is cis-1,4-polybutadiene rubber modified with syn-1,2-PB, and the trade name UBEPOL “VCR” of Ube Industries, Ltd. can be used.

  In the tire 1 of the present invention, the inner liner in which the modulus ratio between the rolling direction and the direction perpendicular thereto is adjusted as described above is adjusted, and the orientation direction is the tire circumferential direction or the axial direction between the right side 11 and the left side 12 of the tire 1. It can be easily manufactured by molding and vulcanizing a green tire by a conventional method. Accordingly, the inner liners 13 and 14 having different tensile moduli in the tire circumferential direction and the axial direction are provided on the left and right sides of the tire 1 with the tread 2 region of the tire 1 as a boundary, and the rigidity is maintained from the inner surface of the tire due to the difference in the modulus of the inner liner. It can be a pneumatic tire having different side rigidity on the left and right sides of the tire.

  The boundary between the inner liners 13 and 14 can be set at an arbitrary position in the tread 2 region, but is divided in the vicinity of the tire center line CL, for example, within 50% of the tread width centering on the center line CL. Is preferred.

  Further, as shown in FIG. 3, the tire 1 is mounted with the side portions 31 that are highly rigid in the tire circumferential direction positioned toward both outer sides of the vehicle.

  The effect of improving the steering stability in this case is that the tire on the front wheel of the vehicle is generally set to toe-in, so when cornering, a load is applied to the tire side part outside the vehicle and the shoulder to buttress part is easily deformed. It is thought that by increasing the outer side rigidity, deformation is suppressed and steering stability is improved.

  Further, in the tire 1, the rigidity in the shoulder region is asymmetrical and the ground pressure distribution is also asymmetrical, and a lateral force is generated from the side having high rigidity to the side having low rigidity when traveling straight. It becomes easy to maintain the steering stability at the time of going straight by making the side which has the vehicle outside. Therefore, as shown in FIG. 4, when the highly rigid side portions 31 are positioned so as to face both inner sides of the vehicle, or the left and right sides of the four tires are randomly mounted, the steering stability of the present invention is achieved. It has been obtained from experimental results that the effect of improving the property cannot be obtained.

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

  Two types of rubber blends A and B for inner liners shown in Table 1 were prepared by using the following rubber components and compounding agents by a conventional method using a Banbury mixer.

[Rubber ingredients, compounding agents]
Bromobutyl rubber: manufactured by Bayer, Bromobutyl 2030
・ Natural rubber: Made in Thailand, RSS # 3
VCR: Ube Industries, Ltd., VCR617 (cis-1,4-polybutadiene component: 83%, syn-1,2-PB component: 17%)
・ Carbon black GPF: manufactured by Tokai Carbon Co., Ltd., Seast V
Aroma oil: JOMO Process X-140, manufactured by Japan Energy Co., Ltd.
・ Petroleum resin: Fujikosan Co., Ltd., Fukkor Resin 120
・ Stearic acid: Lunac S-20, manufactured by Kao Corporation
・ Vulcanization accelerator NS: Sanshin Chemical Industry Co., Ltd., Sunseller NS-G
・ Vulcanization accelerator DM: Sanshin Chemical Industry Co., Ltd., Sunseller DM-G
・ Sulfur: Tsurumi Chemical Co., Ltd., powdered sulfur ・ Zinc flower: Sakai Chemical Industry Co., Ltd., 2 types of zinc oxide

  The air permeability of the obtained rubber composition was evaluated according to the following method. The results are shown in Table 1. Next, these rubber compositions were rolled by a reverse L-shaped calendar to produce an inner liner having a thickness of 0.5 mm. In addition, each inner liner changed the roll rotation speed ratio of the reverse L-shaped calendar to adjust the orientation, and anisotropy was given to the roll alignment direction of the inner liner and its perpendicular direction. The quantification of the anisotropy was performed by the ratio E′p / E′r or E′r / E′p of the dynamic elastic modulus E ′ between the line direction and the direction perpendicular thereto. The measuring method of E 'is as follows.

  Next, for the inner liner, the inner liner orientation direction (E'p / E'r or E'r / E'p) is set in the tire circumferential direction on the right and left sides of the tire with the tire center line CL as a boundary. Alternatively, a green tire was molded along the axial direction, and vulcanized according to a conventional method to produce a test tire.

  The test tire is 215 / 55R17 in size. The carcass is polyester cord 1100 dtex / 2 (punch density 23/25 mm) 2 plies, the belt is steel cord 2 + 2 × 0.25 mm (drive density 25/25 mm) 2 plies, and the cap ply is nylon 66 cord 940 dtex / One ply of 2 (drive density 21/25 mm) was used.

  Next, four identical test tires are mounted on a passenger car so that the right and left sides of the tire are positioned on the outside or inside of the vehicle as shown in FIG. Noise and steering stability were evaluated by the following methods. The results are shown in Table 2.

[Air permeability]
Using the rubber composition described above, a rubber sheet having a thickness of 1 mm was prepared by press vulcanization at 160 ° C. for 20 minutes under a pressure of 50 kgf / cm ² , and conformed to the differential pressure method (A method) described in JIS K7126 The air permeability ratio was measured. It shows by the index | exponent display which sets the mixing | blending A to 100, and the air permeability is so low that it is small, and it is favorable.

[Dynamic elastic modulus E ']
Samples taken from the direction of rolls of each inner liner and the direction perpendicular thereto are vulcanized and prepared on strips of 0.3 mm thickness x 5 mm width x 10 mm length at 160 ° C for 20 minutes to obtain dynamic viscoelasticity. Using a spectrometer (manufactured by Ueshima Seisakusho Co., Ltd.), the dynamic elastic modulus E ′ was measured under conditions of an initial strain of 10%, a dynamic strain of 5%, a frequency of 10 Hz, and an ambient temperature of 23 ° C.

[Steering stability]
Adjust the air pressure to 220 / 200kPa (front wheel / rear wheel) using a rim of size 17 × 7JJ, install it on “Crown” manufactured by Toyota Motor Corporation, and test course for driving stability evaluation (asphalt dry road surface) , The straightness at a speed of 80 km / h, lane changeability, and handling at cornering were evaluated by the feelings of three test drivers, and the average was taken. With Comparative Example 1 as the reference “± 0”, “+1” is slightly superior, “+2” is excellent, “−1” is slightly inferior, and “−2” is inferior.

[Ride comfort]
Under the same conditions as steering stability, run on three test courses of good road, rough road and bump step road at 60 km / h, and each road has a rugged feeling, a bull feeling, and shock absorption when getting over the bump. The characteristics and damping were comprehensively evaluated by the feeling of three test drivers, and the average was taken. With Comparative Example 1 as the reference “± 0”, “+1” is slightly superior, “+2” is excellent, “−1” is slightly inferior, and “−2” is inferior.

[Road noise]
Under the same conditions as steering stability, a microphone was placed at the ear of the driver's seat, and when two people boarded, the asphalt dry road surface was run at a constant speed of 60 km / h, and a road noise level of 100 to 315 Hz was measured. The measured values are shown as being superior on the + side and inferior on the − side, with Comparative Example 1 as the reference “± 0”.

  As shown in Table 2, in Examples 1 to 3, it can be confirmed that the steering stability is improved without impairing road noise and riding comfort, and the modulus ratio E′p / E′r of the inner liner is 1. If it is 1 or more, the effect of improving steering stability is clear. Further, in Comparative Example 2 in which the mounting method is changed with respect to Example 2, no improvement in steering stability is observed, and in Comparative Example 3 in which the circumferential modulus ratio of the entire inner liner is 1.1 or more, the steering stability is improved. Although the improvement effect was obtained, the ride quality deteriorated.

It is a half sectional view of the pneumatic tire of an embodiment. It is explanatory drawing which shows a tire inner surface part. It is explanatory drawing of the tire mounting method of embodiment. It is explanatory drawing of the tire mounting method of a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pneumatic tire 2 ... Tread part 3 ... Side wall part 4 ... Bead part 5 ... Bead core 6 ... Carcass 7 ... Belt 8 ... Cap ply 10 ... Inner liner 13 ... Right inner liner 14 …… Left inner liner CL …… Center line

Claims (4)

When installing a pneumatic tire with different inner liners on the left and right in the axial direction of the tire on the vehicle, the pneumatic tire is mounted with the right side of the tire positioned on both outer sides of the vehicle,
The right inner liner has a larger tensile modulus in the tire circumferential direction than the tensile modulus in the tire axial direction, and the left inner liner has a larger tensile modulus in the tire axial direction than the tensile modulus in the tire circumferential direction. . The right inner liner has a ratio (E′p / E′r) of a dynamic elastic modulus E′p along the tire circumferential direction to a dynamic elastic modulus E′r along the tire axial direction of 1.1 or more. The left inner liner has a ratio (E′r / E′p) between the dynamic elastic modulus E′r along the tire axial direction and the dynamic elastic modulus E′p along the tire circumferential direction. The pneumatic tire according to claim 1, wherein the pneumatic tire is 1.1 or more. The right inner liner is made of an inner liner rubber having orientation in a tire circumferential direction, and the left inner liner is made of an inner liner rubber having orientation in a tire axial direction. The pneumatic tire described in 1. The pneumatic tire according to any one of claims 1 to 3, wherein the left and right inner liners are divided left and right on a tire circumference with a tread region of the tire as a boundary.

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