JPWO2020095891A1 - Run flat tire - Google Patents

Abstract

A pair of bead cores, a carcass that straddles the pair of bead cores and whose ends are locked to the bead core, and an inner liner provided on the inner surface side of the tire of the carcass. Side reinforcing rubber provided in direct contact with the inner liner between the inner liner having a rubber content of 20% by mass or more and the carcass and inner liner on the side of the tire and extending in the tire radial direction along the inner surface of the carcass. A run-flat tire including a layer, a belt layer provided on the tire radial outer side of the carcass and having a cord and a cord coating layer covering the cord and containing a resin, and a tread provided on the tire radial outer side of the belt layer. tire

Description

The present disclosure relates to run-flat tires.

A side-reinforced run-flat tire is known in which the side portion of the tire is reinforced with side reinforcing rubber to ensure durability during run-flat running (during abnormal running when the air pressure drops).
For example, Patent Document 1 proposes a run-flat tire in which an inner liner containing a non-diene rubber and a side reinforcing rubber layer containing a diene rubber contain the same type of vulcanization accelerator.

On the other hand, as one of the attempts to improve the durability of the tire (for example, stress resistance, internal pressure resistance and rigidity), a reinforcing cord member in which a reinforcing cord, which is a metal member, is spirally wound is provided on the outer circumference of the tire body. It has been. In recent years, as a reinforcing cord member, a member in which a resin-coated cord in which the periphery of the reinforcing cord is coated with a resin is wound is also used.
For example, Patent Document 2 describes a tire formed of at least a thermoplastic resin material and having an annular tire skeleton, which is wound around the outer peripheral portion of the tire skeleton in the circumferential direction to form a reinforcing cord layer. A tire having a reinforcing cord member and having the reinforcing cord layer containing a resin material has been proposed.

Patent Document 1: Patent No. 5629786 Patent Document 2: Japanese Patent Application Laid-Open No. 2012-046025

Patent Document 2 describes a tire having a reinforcing cord member containing a resin material as described above. However, there is no description about the side reinforcing rubber layer and the inner liner, and there is no description focusing on the adhesiveness between the two and the internal pressure retention due to air permeation.
Here, the inner liner provided for the purpose of suppressing air permeation of the pneumatic tire and maintaining the internal pressure and the side reinforcing rubber layer provided for reinforcing the tire side portion that supports the load during run-flat running are respectively. A rubber material having a composition suitable for the purpose of is used.
Therefore, in a run-flat tire provided with the inner liner and the side reinforcing rubber layer in direct contact with each other, the adhesiveness of the interface is low due to the different compositions of the two, and peeling may occur during run-flat running. Then, when the interface is peeled off, the portion may affect the run-flat running performance (that is, the durability during running-flat running).
On the other hand, Patent Document 1 describes a run-flat tire in which the side reinforcing rubber layer and the inner liner contain the same type of vulcanization accelerator to improve the adhesiveness between the two. However, as described above, since a rubber material having a composition suitable for each purpose is used for the inner liner and the side reinforcing rubber layer, it is preferable that the degree of freedom in selecting the vulcanization accelerator in each layer is high from this viewpoint. ..
On the other hand, if the composition of the inner liner and the composition of the side reinforcing rubber layer are brought close to each other in order to enhance the adhesiveness of the interface, it becomes difficult to achieve the respective purposes. Therefore, it is difficult to achieve both the internal pressure retention of the tire and the run-flat running performance.

In consideration of the above facts, it is an object of the present disclosure to provide a run-flat tire having both internal pressure retention and run-flat running performance.

Specific means for solving the above problems include the following embodiments.
<1> A pair of bead cores and
A carcass straddling the pair of bead cores and having an end locked to the bead core,
An inner liner provided on the inner surface side of the tire of the carcass, wherein the content of diene rubber is 20% by mass or more with respect to the total amount of rubber contained in the inner liner.
A side reinforcing rubber layer provided in direct contact with the inner liner between the carcass and the inner liner of the tire side portion and extending in the tire radial direction along the inner surface of the carcass.
A belt layer provided on the outer side of the carcass in the tire radial direction and having a cord and a cord coating layer covering the cord and containing a resin.
A tread provided on the outer side of the belt layer in the tire radial direction and
Run-flat tires equipped with.

According to the present disclosure, it is possible to provide a run-flat tire having both internal pressure retention and run-flat running performance.

It is a half cross-sectional view which shows one side of the cut surface which cut along the tire width direction and the tire diameter direction in the state which the run-flat tire which concerns on one Embodiment of this disclosure is assembled to a rim. It is a partially enlarged sectional view which shows the bead core in the run-flat tire which concerns on one Embodiment of this disclosure. It is a perspective view which shows the belt layer in the run-flat tire which concerns on one Embodiment of this disclosure. FIG. 5 is a partially enlarged cross-sectional view showing a modified example in which a bead core is formed by a wire bundle in which a plurality of bead wires are coated with a coating resin in a run-flat tire according to an embodiment of the present disclosure. A semi-cross-sectional view showing a modified example of a run-flat tire according to an embodiment of the present disclosure, in which a belt layer is formed by using a resin-coated cord having a substantially parallel quadrilateral cross section in which a plurality of reinforcing cords are coated with a coating resin. Is.

Hereinafter, specific embodiments of the present disclosure will be described in detail, but the present disclosure is not limited to the following embodiments, and is carried out with appropriate modifications within the scope of the purpose of the present disclosure. be able to.
The size of the members in each figure is conceptual, and the relative relationship between the members is not limited to this. In addition, members having substantially the same function may be designated by the same reference numerals throughout the drawings, and duplicate description may be omitted.

As used herein, the term "resin" is a concept that includes a thermoplastic resin, a thermoplastic elastomer, and a thermosetting resin, and does not include vulcanized rubber. Further, in the following description of the resin, the “same type” means a resin having a skeleton common to the skeleton constituting the main chain of the resin, such as ester-based resins and styrene-based resins.
The numerical range represented by using "~" in the present specification means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.
In the present specification, the amount of each component in the composition is the sum of the plurality of substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition. Means quantity.
As used herein, the term "principal component" means the component having the highest mass-based content in the mixture, unless otherwise specified.

Further, in the present specification, the "thermoplastic resin" means a polymer compound which softens and flows as the temperature rises and becomes relatively hard and strong when cooled, but does not have rubber-like elasticity.
As used herein, the term "thermoplastic elastomer" means a copolymer having a hard segment and a soft segment. Specifically, as the thermoplastic elastomer, for example, a polymer constituting a crystalline hard segment having a high melting point or a hard segment having a high cohesive force, and a polymer constituting an amorphous soft segment having a low glass transition temperature may be used. Examples thereof include copolymers having. Examples of the thermoplastic elastomer include those in which the material softens and flows as the temperature rises, becomes relatively hard and strong when cooled, and has rubber-like elasticity.
The hard segment refers to a component that is relatively harder than the soft segment. The hard segment is preferably a molecular restraint component that serves as a cross-linking point of the cross-linked rubber that prevents plastic deformation. The hard segment is, for example, a segment having a rigid group such as an aromatic group or an alicyclic group in the main skeleton, or a structure that enables intermolecular packing by intermolecular hydrogen bonds or π-π interactions. Can be mentioned. Further, the soft segment refers to a component that is relatively softer than the hard segment. The soft segment is preferably a flexible component exhibiting rubber elasticity. Examples of the soft segment include a segment having a long-chain group (for example, a long-chain alkylene group) in the main chain, a high degree of freedom in molecular rotation, and a stretchable structure.

[Run-flat tire]
FIG. 1 shows a cut surface (along the tire circumferential direction) cut along the tire width direction and the tire radial direction in an example of a run-flat tire according to an embodiment of the present disclosure (hereinafter, referred to as “tire 10”). One side of the cross section (cross section seen from the vertical direction) is shown.
In the figure, the arrow W indicates the width direction of the tire 10 (tire width direction), and the arrow R indicates the radial direction of the tire 10 (tire radial direction). The tire width direction referred to here refers to a direction parallel to the rotation axis of the tire 10. Further, the tire radial direction means a direction orthogonal to the rotation axis of the tire 10. Further, the reference numeral CL indicates the equatorial plane (tire equatorial plane) of the tire 10.

Further, in the present embodiment, the side close to the rotation axis of the tire 10 along the tire radial direction is "inside in the tire radial direction", and the side far from the rotation axis of the tire 10 along the tire radial direction is "outside in the tire radial direction". It is described as. On the other hand, the side close to the tire equatorial plane CL along the tire width direction is described as "inside in the tire width direction", and the side far from the tire equatorial plane CL along the tire width direction is described as "outside in the tire width direction".

FIG. 1 shows a tire 10 when assembled on a rim 30 which is a standard rim and filled with standard air pressure. The "standard rim" here refers to the rim specified by JATMA (Japan Automobile Tire Association) Year Book 2018 edition. The standard air pressure is the air pressure corresponding to the maximum load capacity of the Year Book 2018 version of JATTA (Japan Automobile Tire Association).

As shown in FIG. 1, the tire 10 is provided on a pair of bead cores 26 embedded in the bead portion 12, a carcass 14 straddling the bead core 26 and having an end portion locked to the bead core 26, and a tire inner surface side of the carcass 14. Side reinforcing rubber 24 (that is, side reinforcing rubber 24 (that is,) provided in direct contact with the inner liner 16 between the provided inner liner 16 and the carcass 14 and the inner liner 16 of the tire side portion 22 and extending in the tire radial direction along the inner surface of the carcass 14. , Side reinforcing rubber layer), a belt layer 40 provided on the tire radial outer side of the tread portion 18 of the carcass 14, and a tread 20 provided on the tire radial outer side of the belt layer 40. In FIG. 1, only the bead portion 12 on one side is shown.

The inner liner 16 is made of a rubber material containing rubber, and contains 20% by mass or more of diene-based rubber with respect to the entire rubber (total amount of rubber) contained in the inner liner 16.
Further, the belt layer 40 is configured to include a reinforcing cord 42C and a coating resin 42S (that is, a cord coating layer) that covers the reinforcing cord 42C and contains a resin. That is, the belt layer 40 contains resin. The details of the resin material constituting the coating resin 42S will be described later.

Here, in general, the inner liner is a layer provided to enhance the internal pressure retention of the tire, and is preferably a layer having low air permeability. Therefore, a rubber other than the diene rubber (that is, a non-diene rubber) It is often composed of a rubber material containing rubber). On the other hand, the side reinforcing rubber is generally a layer for reinforcing the tire side portion that supports the load acting on the tire during run-flat running, and it is desirable that the side reinforcing rubber has a hardness high enough to be reinforced. Therefore, it is composed of a rubber material having a composition different from that of the inner liner. Therefore, even if vulcanization is performed in a state where the unvulcanized inner liner and the unvulcanized side reinforcing rubber are in contact with each other, the adhesive force at the interface is unlikely to increase.
Further, in order to enhance the adhesive force of the interface, for example, if the composition of the rubber material used for the inner liner is made close to the composition of the rubber material used for the side reinforcing rubber, the adhesive force of the interface is increased, but the air permeability of the inner liner is increased. May also increase and the internal pressure retention may decrease.

On the other hand, in the tire 10, the inner liner 16 in direct contact with the side reinforcing rubber 24 contains 20% by mass or more of diene-based rubber with respect to the entire rubber (total amount of rubber), and the belt layer 40 contains resin. .. As a result, both internal pressure retention and run-flat running performance are compatible. The reason is not clear, but it is presumed as follows.

In the process of manufacturing the side reinforcing rubber 24, vulcanization is performed at a relatively high vulcanization rate for the purpose of forming a layer having a hardness high enough to reinforce the tire side portion 22. When the inner liner 16 contains 20% by mass or more of diene-based rubber, the vulcanization rate is faster and the vulcanization rates of both are closer to each other in the process of manufacturing the inner liner 16 as compared with the case where the diene-based rubber is not contained. it is conceivable that. Therefore, if vulcanization is performed with the unvulcanized inner liner and the unvulcanized side reinforcing rubber in contact with each other, both are vulcanized at similar speeds, which facilitates co-crosslinking and the adhesive force at the interface. Is presumed to be high.
In particular, when the side reinforcing rubber 24 contains a diene rubber, the inner liner 16 also contains 20% by mass or more of the diene rubber, so that co-crosslinking occurs further as compared with the case where the inner liner 16 does not contain the diene rubber. It is easy, and it is presumed that the adhesive strength at the interface will be higher.
In this way, the adhesive force between the inner liner 16 and the side reinforcing rubber 24 is increased, so that the interface is less likely to peel off and the run-flat running performance is improved.

In addition, since the belt layer 40 contains the resin, the internal pressure retention of the entire tire 10 can be easily maintained. That is, resin is used for the belt layer provided in the tread portion, which is a region of the tire that tends to cause a decrease in internal pressure retention due to air permeation. Resin generally has lower air permeability than rubber. Therefore, even if the inner liner contains diene rubber and the air barrier property of the inner liner itself is lowered, the air permeability in the tread portion can be kept low, and the internal pressure holding property of the tire as a whole is maintained. ..
As described above, it is presumed that the tire 10 has both internal pressure retention and run-flat running performance.
Hereinafter, each part of the tire 10 will be described.

<Bead part>
A bead core 26 including a wire bundle is embedded in each of the pair of bead portions 12. A carcass 14 straddles these bead cores 26. The bead core 26 can adopt various structures in a pneumatic tire such as a circular cross section and a polygonal shape, and a hexagonal shape can be adopted as the polygonal shape, but in the present embodiment, it is a quadrangle. There is.

As shown in FIG. 2, the bead core 26 has, for example, a bead wire 26A and a coating resin 26B (that is, a bead coating layer) that coats the bead wire 26A and contains a resin. The bead core 26 is formed by winding one bead wire 26A coated on the coating resin 26B a plurality of times and laminating them. Specifically, the bead wire 26A coated with the coating resin 26B is wound tightly in the tire width direction to form the first row, and thereafter, the bead wires 26A are stacked outward in the tire radial direction without gaps in the same manner, and the cross-sectional shape is quadrangular. Bead core 26 is formed. At this time, the coating resins 26B of the bead wires 26A adjacent to each other in the tire width direction and the radial direction are joined to each other. As a result, the bead core 26 in which the bead wire 26A is coated with the coating resin 26B is formed.

In the tire 10 shown in FIGS. 1 and 2, not only the belt layer 40 but also the bead core 26 contains resin, so that the internal pressure holding property of the tire 10 can be easily maintained, and the internal pressure holding property and the run-flat running property are more compatible. Will be done. As the resin material constituting the coating resin 26B, the same resin material as the resin material constituting the coating resin 42S described later is used.

In the present embodiment, the bead core 26 is formed by winding one bead wire 26A coated with the coating resin 26B and laminating it, but the embodiment of the present disclosure is not limited to this. For example, as in the bead core 60 shown in FIG. 4, a plurality of bead wires 60A may be formed by winding and laminating a wire bundle coated with a coating resin 60B.

In this case, the interface at the time of lamination is fused by heat welding. The number of bead wires 60A included in one wire bundle is not limited to three, and may be two or four or more. Further, the number of wire bundles in each layer on which the wire bundles are laminated may be one bundle as shown in FIG. 4, or may be two or more bundles adjacent to each other in the tire width direction.

In the present embodiment, the bead wire 26A is coated with the coating resin 26B to form the bead core 26, but the embodiment of the present disclosure is not limited to this. For example, a coated rubber containing rubber may be used instead of the coated resin 26B.

As shown in FIG. 1, the tire 10 further includes a bead filler 28 embedded in the bead portion 12 and extending outward from the bead core 26 in the radial direction of the tire along the outer surface of the carcass 14. The bead filler 28 contains a resin and is embedded in a region surrounded by the carcass 14 of the bead portion 12 (a region outside the portion of the carcass 14 arranged inside the bead core 26 in the tire width direction). Further, the bead filler 28 has a thickness decreasing toward the end portion 28A on the outer side in the tire radial direction.

In the tire 10 shown in FIGS. 1 and 2, not only the belt layer 40 but also the bead filler 28 contains the resin, so that the internal pressure holding property of the tire 10 can be easily maintained, and the internal pressure holding property and the run-flat running property can be improved. More compatible. As the resin material constituting the bead filler 28, the same resin material as that constituting the coating resin 42S described later is used.

In the present embodiment, the bead filler 28 containing a resin is used, but the embodiment of the present disclosure is not limited to this, and includes, for example, rubber (preferably containing rubber as a main component (for example, for the entire bead filler). 50% by mass or more)) A bead filler may be used.

<Carcass>
The carcass 14 is a tire skeleton member composed of two carcass plies 14A and 14B. The carcass ply 14A is a carcass ply arranged on the outer side in the tire radial direction on the tire equatorial plane CL, and the carcass ply 14B is a carcass ply arranged on the inner side in the tire radial direction. The carcass ply 14A and 14B are each composed of a plurality of cords and a coated rubber that covers the cords and includes rubber.
The coated rubber is not particularly limited, and examples thereof include a rubber material containing a diene-based rubber (for example, natural rubber). In particular, when the coating rubber contains a diene rubber and the carcass 14 and the inner liner 16 are in direct contact with each other, the inner liner 16 contains 20% by mass or more of the diene rubber so that the inner liner 16 and the carcass 14 are in direct contact with each other. Adhesion with is also high. Therefore, the run-flat runnability is further improved.

The carcass 14 thus formed extends from one bead core 26 to the other bead core 26 in a toroid shape to form a tire skeleton. Further, the end side of the carcass 14 is locked to the bead core 26. Specifically, the carcass 14 is locked so that the end side is folded back around the bead core 26 from the inside in the tire width direction to the outside in the tire width direction. Further, the folded ends (ends 14AE, 14BE) of the carcass 14 are arranged on the tire side portion 22. The end portion 14AE of the carcass ply 14A is arranged inside the end portion 14BE of the carcass ply 14B in the tire radial direction.

In the present embodiment, the end portion of the carcass 14 is arranged on the tire side portion 22, but the present disclosure is not limited to this configuration. For example, the end portion of the carcass 14 is arranged on the belt layer 40. May be good. Further, it is also possible to adopt a structure in which the end side of the carcass 14 is not folded back and is sandwiched between a plurality of bead cores 26 or wound around the bead core 26. As used herein, "locking" the end of the carcass 14 to the bead core 26 includes various embodiments such as these.

In the present embodiment, the carcass 14 is a radial carcass. The material of the cord contained in the carcass 14 is not particularly limited, and rayon, nylon, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), aramid, glass fiber, carbon fiber, steel and the like can be adopted. From the viewpoint of weight reduction, the organic fiber cord is preferable. Further, the number of carcass driven is in the range of 20 to 60/50 mm, but the number is not limited to this range.

<Belt layer>
A belt layer 40 is arranged on the outer side of the carcass 14 in the tire radial direction. As shown in FIG. 3, the belt layer 40 is a ring-shaped sword formed by spirally winding the resin coating cord 42 around the outer peripheral surface of the carcass 14 along the tire circumferential direction.

The resin-coated cord 42 is configured by coating the reinforcing cord 42C with the coating resin 42S, and has a substantially square cross section as shown in FIG. The coating resin 42S of the inner peripheral portion of the resin coating cord 42 in the tire radial direction is formed, for example, joined to the outer peripheral surface of the carcass 14 via rubber and, if necessary, an adhesive. Further, the coating resins 42S adjacent to each other in the tire width direction of the resin coating cord 42 are integrally joined by heat welding or an adhesive or the like. As a result, the belt layer 40 (resin-coated belt layer) made of the reinforcing cord 42C coated with the coating resin 42S is formed.

In the present embodiment, the resin coating cord 42 is configured by coating one reinforcing cord 42C with the coating resin 42S, but may be configured by coating a plurality of reinforcing cords 42C with the coating resin 42S. good.

Further, the bead wire 26A in the bead core 26 and the reinforcing cord 42C in the belt layer 40 of the present embodiment are each made of steel cord. This steel cord contains steel as a main component and can contain various trace substances such as carbon, manganese, silicon, phosphorus, sulfur, copper and chromium.

The embodiment of the present disclosure is not limited to this, and as at least one selected from the group consisting of the bead wire 26A and the reinforcing cord 42C, instead of the steel cord, a monofilament cord, a cord obtained by twisting a plurality of filaments, etc. May be used. Various designs can be adopted for the twist structure, and various designs can be used for the cross-sectional structure, the twist pitch, the twist direction, and the distance between adjacent filaments. Further, a cord in which filaments of different materials are twisted can be adopted, and the cross-sectional structure is not particularly limited, and various twisted structures such as single twist, layer twist, and double twist can be adopted. Further, a resin cord (that is, a cord containing resin) may be used as at least one selected from the group consisting of the bead wire 26A and the reinforcing cord 42C.

Further, in the present embodiment, the belt layer 40 is formed by winding a substantially square resin-coated cord 42 formed by coating one reinforcing cord 42C with a coating resin 42S around the outer peripheral surface of the carcass 14. The embodiments of the present disclosure are not limited to this.
For example, like the belt layer 70 shown in FIG. 5, a resin-coated cord 72 having a substantially parallel quadrilateral cross section formed by coating a plurality of reinforcing cords 72C with a coating resin 72S is wound around the outer peripheral surface of the carcass 14. May be formed.

<Tread>
A tread 20 is provided on the outer side of the belt layer 40 in the tread portion 18 in the tire radial direction. The tread 20 is a portion that comes into contact with the road surface during traveling, and a plurality of circumferential grooves 50 extending in the tire circumferential direction are formed on the tread surface of the tread 20. The shape and number of the circumferential grooves 50 are appropriately set according to the performance such as drainage and steering stability required for the tire 10.

<Inner liner>
The inner liner 16 is provided as a continuous layer on the tire inner surface side of the carcass 14 (that is, the inside of the bead portion 12 in the tire width direction, the inside of the tire side portion 22 in the tire width direction, and the inside of the tread portion 18 in the tire radial direction). ing. The inner liner 16 is a layer provided for increasing the internal pressure holding property of the tire 10 by reducing the air permeability.
The inner liner 16 is provided in direct contact with at least the inner peripheral surface of the side reinforcing rubber 24 (that is, the inner surface in the tire width direction). On the other hand, in the tire 10, the inner liner 16 is provided in direct contact with the inner peripheral surface (that is, the inner surface in the tire radial direction) of the tread portion 18 of the carcass 14, but the present invention is not limited to this, and the carcass 14 and the inner are not limited to this. Another layer may be provided between the liner 16 and the liner 16.

Further, in the tire 10, the inner liner 16 is provided as a continuous layer from one bead portion 12 to the other bead portion 12. The inner liner 16 is not limited to this as long as it is provided in contact with at least a part of the side reinforcing rubber 24 in a region where it is desirable to block air, but from the viewpoint of internal pressure retention, the inner liner 16 of the tire 10 It is preferable that it is provided on the entire inner surface.
Examples of the thickness of the inner liner 16 include a range of 0.1 mm or more and 0.4 mm or less. The thickness of the inner liner 16 may be the same from one bead portion 12 to the other bead portion 12, and the region where it is particularly desirable to reduce air permeability may be relatively thick.

The inner liner 16 contains at least a diene rubber. The content of the diene-based rubber with respect to the entire rubber (total amount of rubber) contained in the inner liner 16 is 20% by mass or more, preferably 35% by mass or more, preferably 50% by mass from the viewpoint of adhesion to the side reinforcing rubber 24. % Or more is more preferable.
When the inner liner 16 contains the diene rubber in the above range, the adhesiveness between the inner liner and the side reinforcing rubber 24 is improved. In addition, when the inner liner 16 is in contact with the carcass 14, the adhesiveness between the inner liner 16 and the carcass 14 is also high.

Here, the diene-based rubber means a rubber containing a double bond in the main chain of the rubber (specifically, containing 2.5 mol% or more). Examples of the diene rubber include natural rubber (NR), polybutadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), acrylonitrile-butadiene copolymer rubber (NBR), and polychloroprene rubber (CR). ) And other synthetic rubbers. One type of diene rubber may be used alone, or two or more types may be used as a mixture.
As the diene rubber, natural rubber (NR) is preferable among these from the viewpoint of adhesiveness to the side reinforcing rubber 24.

The inner liner 16 preferably contains a non-diene rubber in addition to the diene rubber from the viewpoint of lowering the air permeability. The content of non-diene rubber in the entire rubber (total amount of rubber) contained in the inner liner 16 is preferably 20% by mass or more, more preferably 30% by mass or more, and more preferably 40% by mass from the viewpoint of lowering air permeability. The above is more preferable. That is, the content of the diene-based rubber with respect to the entire rubber (total amount of rubber) contained in the inner liner 16 is preferably 80% by mass or less, more preferably 70% by mass or less, and more preferably 60% by mass, from the viewpoint of lowering the air permeability. More preferably, it is by mass or less.

Here, the non-diene rubber means a rubber having almost no double bond (specifically, less than 2.5 mol%) in the main chain of the rubber. Examples of non-diene rubber include butyl rubber (butyl rubber (IIR), butyl halogenated rubber, etc.), ethylene / propylene rubber (EPM, EPDM), urethane rubber (U), silicone rubber (Q), and chlorosulfonated rubber. (CSM), acrylic rubber (ACM), fluororubber (FKM), chlorosulfonated polyethylene and the like can be mentioned.
As the non-diene rubber, butyl rubber is preferable among them from the viewpoint of lowering air permeability, and butyl rubber (IIR) and bromobutyl rubber are more preferable among them.

The rubber material constituting the inner liner 16 may contain other components other than rubber, if necessary, in addition to rubber.
Other components include, for example, reinforcing materials such as carbon black, fillers (fillers, short fibers, resins, etc.), vulcanizing agents, vulcanization accelerators, fatty acids or salts thereof, metal oxides, process oils, antiaging. Agents and the like can be mentioned.
As the vulcanizing agent, known vulcanizing agents such as sulfur, organic peroxides, resin vulcanizing agents and the like are used. Among them, it is preferable that sulfur is used as the vulcanizing agent.
As the vulcanization accelerator, known vulcanization accelerators such as aldehydes, ammonia, amines, guanidines, thioureas, thiazoles, sulfenamides, thiurams, dithiocarbamates, xanthates and the like are used. Be done.
Examples of the fatty acid include stearic acid, palmitic acid, myristic acid, lauric acid and the like, and these may be blended in a salt state such as zinc stearate. Of these, stearic acid is preferred.
Examples of the metal oxide include zinc oxide (ZnO), iron oxide, magnesium oxide and the like, and zinc oxide is preferable.
As the process oil, any of aromatic type, naphthen type and paraffin type may be used. Examples of the antiaging agent include amine-ketone type, imidazole type, amine type, phenol type, sulfur type and phosphorus type.

<Side reinforcement rubber>
The tire side portion 22 extends in the tire radial direction to connect the bead portion 12 and the tread portion 18 so that the load acting on the tire 10 can be borne during run-flat running. Inside the tire side portion 22 of the carcass 14 in the tire width direction, a side reinforcing rubber 24 for reinforcing the tire side portion 22 is provided. Specifically, the side reinforcing rubber 24 is provided between the carcass 14 and the inner liner 16 in direct contact with at least the inner liner 16. The side reinforcing rubber 24 is a reinforcing rubber for traveling a predetermined distance while supporting the weights of the vehicle and the occupant when the internal pressure of the tire 10 is reduced due to puncture or the like.

The side reinforcing rubber 24 extends from the bead portion 12 side to the tread 20 side in the tire radial direction along the inner surface of the carcass 14. Further, the side reinforcing rubber 24 has a shape in which the thickness decreases from the central portion toward the bead portion 12 side and the tread 20 side, for example, a substantially crescent shape. The thickness of the side reinforcing rubber 24 referred to here refers to the length along the normal line of the carcass 14.

The lower end portion 24B of the side reinforcing rubber 24 on the bead portion 12 side overlaps the bead filler 28 with the carcass 14 in between when viewed from the tire width direction. Further, the upper end portion 24A of the side reinforcing rubber 24 on the tread 20 side overlaps with the belt layer 40 when viewed from the tire radial direction. Specifically, the upper end portion 24A of the side reinforcing rubber 24 overlaps the belt layer 40 with the carcass 14 interposed therebetween. In other words, the upper end portion 24A of the side reinforcing rubber 24 is located inside the tire width direction end portion 40E of the belt layer 40 in the tire width direction.

In the present embodiment, the side reinforcing rubber 24 is formed of one type of rubber material, but the embodiment of the present disclosure is not limited to this, and may be formed of a plurality of rubber materials.
The side reinforcing rubber 24 preferably contains rubber as a main component, and from the viewpoint of run-flat running performance, it preferably contains a diene-based rubber, and more preferably contains butadiene rubber (BR). It is also preferable to include butadiene rubber (BR) and natural rubber (NR).
The content of the diene-based rubber with respect to the entire rubber (total amount of rubber) contained in the side reinforcing rubber 24 is preferably 70% by mass or more, more preferably 90% by mass or more, from the viewpoint of run-flat running performance.

The rubber material constituting the side reinforcing rubber 24 may contain other components other than rubber, if necessary, in addition to rubber. Examples of other components include the same components as other components that may be contained in the rubber material constituting the inner liner 16 as needed.
Among them, the rubber material constituting the side reinforcing rubber 24 preferably contains a thiuram-based accelerator as a vulcanization accelerator in order to enhance durability during run-flat running.

The hardness of the side reinforcing rubber 24 is preferably 70 or more and 85 or less from the viewpoint of run-flat running performance. The hardness of the side reinforcing rubber 24 refers to the hardness specified by JIS K6253 (type A durometer).
Further, the loss coefficient tan δ of the side reinforcing rubber 24 at a temperature of 60 ° C. and a frequency of 20 Hz is preferably 0.10 or less. The loss coefficient tan δ is a value measured using a viscoelastic spectrometer (a spectrometer manufactured by Toyo Seiki Seisakusho) under the conditions of a frequency of 20 Hz, an initial strain of 10%, a dynamic strain of ± 2%, and a temperature of 60 ° C.

<Resin material>
Hereinafter, the resin material used for the coating resin 42S in the belt layer 40 will be described. As the resin material used for the coating resin 26B and the bead filler 28 in the bead core 26, the same resin material as that used for the coating resin 42S in the belt layer 40 is used.
The resin material contains at least a resin and may contain other components if necessary.
The resin material preferably contains a resin as a main component. Specifically, the content of the resin with respect to the total amount of the resin material is preferably 50% by mass or more, more preferably 60% by mass or more, and further preferably 75% by mass or more.
The resin material may contain any of a thermoplastic resin, a thermoplastic elastomer, and a thermoplastic resin as the resin, but preferably contains at least one selected from the group consisting of the thermoplastic resin and the thermoplastic elastomer. More preferably, it contains a thermoplastic elastomer.

Examples of the thermoplastic resin include polyester-based thermoplastic resin, polyamide-based thermoplastic resin, polystyrene-based thermoplastic resin, polyurethane-based thermoplastic resin, polyolefin-based thermoplastic resin, vinyl chloride-based thermoplastic resin, and the like.

Examples of the thermoplastic elastomer include polyester-based thermoplastic elastomer (TPC), polyamide-based thermoplastic elastomer (TPA), polystyrene-based thermoplastic elastomer (TPS), and polyurethane-based thermoplastic elastomer (TPU) specified in JIS K6418. Examples thereof include a polyolefin-based thermoplastic elastomer (TPO), a thermoplastic rubber crosslinked product (TPV), and other thermoplastic elastomers (TPZ).

Examples of the thermosetting resin include phenol-based thermosetting resins, urea-based thermosetting resins, melamine-based thermosetting resins, epoxy-based thermosetting resins, and the like.

The resin material may contain these resins alone, or may contain two or more kinds of resins in combination.
Among these, as the resin, polyester-based thermoplastic elastomer, polyester-based thermoplastic resin, polyamide-based thermoplastic elastomer, polyamide-based thermoplastic resin, polystyrene-based thermoplastic elastomer, polystyrene-based thermoplastic resin, polyurethane-based thermoplastic elastomer, Polyurethane-based thermoplastic resins, polyolefin-based thermoplastic elastomers, or polyolefin-based thermoplastic resins are preferable.
The resin material preferably contains at least one selected from the group consisting of polyester-based thermoplastic elastomers, polyester-based thermoplastic resins, polyamide-based thermoplastic elastomers, and polyamide-based thermoplastic resins, and preferably contains polyester-based thermoplastic elastomers and polyesters. It is more preferable to contain at least one selected from the group consisting of based thermoplastic resins.

-Thermoplastic elastomer-
(Polyester-based thermoplastic elastomer)
As the polyester-based thermoplastic elastomer, for example, at least polyester forms a hard segment having a high crystallinity and a high melting point, and another polymer (for example, polyester or polyether) is amorphous and has a low glass transition temperature. Examples include the forming material.

As the polyester forming the hard segment, aromatic polyester can be used. The aromatic polyester can be formed from, for example, an aromatic dicarboxylic acid or an ester-forming derivative thereof and an aliphatic diol. The aromatic polyester is preferably polybutylene terephthalate derived from at least one selected from the group consisting of terephthalic acid and dimethyl terephthalate, and 1,4-butanediol. The aromatic polyesters include, for example, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyetanedicarboxylic acid, 5 -Dicarboxylic acid components such as sulfoisophthalic acid or ester-forming derivatives thereof and diols having a molecular weight of 300 or less (for example, ethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, decamethylene glycol, etc.) Aromatic diols; 1,4-cyclohexanedimethanol, alicyclic diols such as tricyclodecanedimethylol; xylylene glycol, bis (p-hydroxy) diphenyl, bis (p-hydroxyphenyl) propane, 2,2- Bis [4- (2-hydroxyethoxy) phenyl] propane, bis [4- (2-hydroxy) phenyl] sulfone, 1,1-bis [4- (2-hydroxyethoxy) phenyl] cyclohexane, 4,4'- Aromatic diols such as dihydroxy-p-terphenyl and 4,4'-dihydroxy-p-quarterphenyl; etc.) and polyesters derived from them, or a combination of two or more of these dicarboxylic acid components and diol components. It may be a polymerized polyester. It is also possible to copolymerize a trifunctional or higher functional polyfunctional carboxylic acid component, a polyfunctional oxyic acid component, a polyfunctional hydroxy component and the like in a range of 5 mol% or less.
Examples of the polyester forming the hard segment include polyethylene terephthalate, polybutylene terephthalate, polymethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate and the like, and polybutylene terephthalate is preferable.

Examples of the polymer forming the soft segment include aliphatic polyesters and aliphatic polyethers.
Examples of the aliphatic polyether include poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, a copolymer of ethylene oxide and propylene oxide, and poly (propylene oxide). ) Glycol ethylene oxide addition polymer, copolymer of ethylene oxide and tetrahydrofuran, etc. can be mentioned.
Examples of the aliphatic polyester include poly (ε-caprolactone), polyenant lactone, polycaprilolactone, polybutylene adipate, polyethylene adipate and the like.
Among these aliphatic polyethers and aliphatic polyesters, poly (tetramethylene oxide) glycol and poly (propylene oxide) glycol are examples of polymers that form soft segments from the viewpoint of the elastic properties of the obtained polyester block copolymer. Ethylene oxide adduct, poly (ε-caprolactone), polybutylene adipate, polyethylene adipate and the like are preferable.

The number average molecular weight of the polymer forming the soft segment is preferably 300 to 6000 from the viewpoint of toughness and low temperature flexibility. Further, the mass ratio (x: y) of the hard segment (x) and the soft segment (y) is preferably 99: 1 to 20:80, more preferably 98: 2 to 30:70 from the viewpoint of moldability. ..

Examples of the combination of the above-mentioned hard segment and the soft segment include the respective combinations of the above-mentioned hard segment and the soft segment. Among these, as the combination of the above-mentioned hard segment and soft segment, a combination in which the hard segment is polybutylene terephthalate and the soft segment is an aliphatic polyether is preferable, and the hard segment is polybutylene terephthalate and the soft segment. More preferably, the combination is poly (ethylene oxide) glycol.

Commercially available polyester-based thermoplastic elastomers include, for example, the "Hytrel" series manufactured by Toray DuPont Co., Ltd. (for example, 3046, 5557, 6347, 4047N, 4767N, etc.) and the "Perprene" series manufactured by Toyobo Co., Ltd. (For example, P30B, P40B, P40H, P55B, P70B, P150B, P280B, E450B, P150M, S1001, S2001, S5001, S6001, S9001, etc.) and the like can be used.

The polyester-based thermoplastic elastomer can be synthesized by copolymerizing a polymer forming a hard segment and a polymer forming a soft segment by a known method.

(Polyamide-based thermoplastic elastomer)
A polyamide-based thermoplastic elastomer is a thermoplastic resin material composed of a copolymer having a polymer that forms a hard segment that is crystalline and has a high melting point and a polymer that forms a soft segment that is amorphous and has a low glass transition temperature. It means a polymer having an amide bond (-CONH-) in the main chain of the polymer forming the hard segment.
As the polyamide-based thermoplastic elastomer, for example, at least polyamide forms a hard segment having a high crystallinity and a high melting point, and other polymers (for example, polyester, polyether, etc.) are amorphous and have a low glass transition temperature. Examples include the forming material. Further, the polyamide-based thermoplastic elastomer may be formed by using a chain length extender such as a dicarboxylic acid in addition to the hard segment and the soft segment.
Specific examples of the polyamide-based thermoplastic elastomer include the amide-based thermoplastic elastomer (TPA) defined in JIS K6418: 2007, and the polyamide-based elastomer described in JP-A-2004-346273. can.

In the polyamide-based thermoplastic elastomer, examples of the polyamide forming the hard segment include a polyamide produced by a monomer represented by the following general formula (1) or general formula (2).

In the general formula (1), R ¹ represents a molecular chain of a hydrocarbon having 2 to 20 carbon atoms (for example, an alkylene group having 2 to 20 carbon atoms).

In the general formula (2), R ² represents a molecular chain of a hydrocarbon having 3 to 20 carbon atoms (for example, an alkylene group having 3 to 20 carbon atoms).

In the general formula (1), as R ¹ , a molecular chain of a hydrocarbon having 3 to 18 carbon atoms, for example, an alkylene group having 3 to 18 carbon atoms is preferable, and a molecular chain of a hydrocarbon having 4 to 15 carbon atoms, for example, carbon. An alkylene group having a number of 4 to 15 is more preferable, and a molecular chain of a hydrocarbon having 10 to 15 carbon atoms, for example, an alkylene group having 10 to 15 carbon atoms is particularly preferable.
Further, in the general formula (2), the ^{R 2,} the molecular chains of hydrocarbon having 3 to 18 carbon atoms, for example, preferably an alkylene group having 3 to 18 carbon atoms, the molecular chain of a hydrocarbon of 4 to 15 carbon atoms, For example, an alkylene group having 4 to 15 carbon atoms is more preferable, and a molecular chain of a hydrocarbon having 10 to 15 carbon atoms, for example, an alkylene group having 10 to 15 carbon atoms is particularly preferable.
Examples of the monomer represented by the general formula (1) or the general formula (2) include ω-aminocarboxylic acid and lactam. Examples of the polyamide forming the hard segment include a polycondensate of these ω-aminocarboxylic acids or lactams, a co-condensation polymer of a diamine and a dicarboxylic acid, and the like.

Examples of the ω-aminocarboxylic acid include 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 10-aminocapric acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and the like having 5 to 20 carbon atoms. An aliphatic ω-aminocarboxylic acid and the like can be mentioned. Examples of the lactam include aliphatic lactams having 5 to 20 carbon atoms such as lauryl lactam, ε-caprolactam, udecan lactam, ω-enantractum, and 2-pyrrolidone.
Examples of the diamine include an aliphatic diamine having 2 to 20 carbon atoms and an aromatic diamine having 6 to 20 carbon atoms. Examples of the aliphatic diamine having 2 to 20 carbons and the aromatic diamine having 6 to 20 carbons include ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, and nonamethylenediamine. Decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 3-methylpentamethylenediamine, metaxamethylenediamine and the like can be mentioned. can.
Further, the dicarboxylic acid can be represented by HOOC- (R ³ ) _m- COOH (R ³ : molecular chain of hydrocarbon having 3 to 20 carbon atoms, m: 0 or 1), for example, oxalic acid, succinic acid. , Glutaric acid, adipic acid, pimelli acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid and other aliphatic dicarboxylic acids having 2 to 20 carbon atoms can be mentioned.
As the polyamide forming the hard segment, a polyamide obtained by ring-opening polycondensation of lauryl lactam, ε-caprolactam, or udecan lactam can be preferably used.

Examples of the polymer forming the soft segment include polyester and polyether, and specific examples thereof include polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, and ABA-type triblock polyether. These can be used alone or in combination of two or more. Further, a polyether diamine or the like obtained by reacting the terminal of the polyether with ammonia or the like can also be used.
Here, the "ABA-type triblock polyether" means a polyether represented by the following general formula (3).

In the general formula (3), x and z represent integers of 1 to 20. y represents an integer from 4 to 50.

In the general formula (3), x and z are preferably integers of 1 to 18, more preferably integers of 1 to 16, even more preferably integers of 1 to 14, and particularly preferably integers of 1 to 12. Further, in the general formula (3), y is preferably an integer of 5 to 45, more preferably an integer of 6 to 40, further preferably an integer of 7 to 35, and particularly preferably an integer of 8 to 30.

Examples of the combination of the hard segment and the soft segment include the respective combinations of the hard segment and the soft segment mentioned above. Among these, the combination of the hard segment and the soft segment includes a combination of lauryl lactam open ring polycondensate / polyethylene glycol, a combination of lauryl lactam open ring polycondensate / polypropylene glycol, and a combination of lauryl lactam open ring polycondensate. A combination of body / polytetramethylene ether glycol or a ring-opened polycondensate of lauryl lactam / ABA-type triblock polyether is preferable, and a combination of lauryl lactam ring-opened polycondensate / ABA-type triblock polyether is more preferable. preferable.

The number average molecular weight of the polymer (polyamide) forming the hard segment is preferably 300 to 15,000 from the viewpoint of melt moldability. The number average molecular weight of the polymer forming the soft segment is preferably 200 to 6000 from the viewpoint of toughness and low temperature flexibility. Further, the mass ratio (x: y) of the hard segment (x) and the soft segment (y) is preferably 50:50 to 90:10, more preferably 50:50 to 80:20 from the viewpoint of moldability. ..

The polyamide-based thermoplastic elastomer can be synthesized by copolymerizing a polymer forming a hard segment and a polymer forming a soft segment by a known method.

Examples of commercially available polyamide-based thermoplastic elastomers include Ube Industries, Ltd.'s "UBESTA XPA" series (for example, XPA9068X1, XPA9063X1, XPA9055X1, XPA9048X2, XPA9048X1, XPA9040X1, XPA9040X2XPA9044, etc.), Daicel Eponic. The "bestamide" series (for example, E40-S3, E47-S1, E47-S3, E55-S1, E55-S3, EX9200, E50-R2, etc.) can be used.

(Polystyrene-based thermoplastic elastomer)
As polystyrene-based thermoplastic elastomers, for example, at least polystyrene forms a hard segment, and other polymers (for example, polybutadiene, polyisoprene, polyethylene, hydrogenated polybutadiene, hydrogenated polyisoprene, etc.) are amorphous and have a glass transition temperature. Examples include materials forming low soft segments. As the polystyrene forming the hard segment, for example, polystyrene obtained by a known radical polymerization method, ionic polymerization method or the like is preferably used, and specific examples thereof include polystyrene having anionic living polymerization. Examples of the polymer forming the soft segment include polybutadiene, polyisoprene, and poly (2,3-dimethyl-butadiene).

Examples of the combination of the hard segment and the soft segment include the respective combinations of the hard segment and the soft segment mentioned above. Among these, as the combination of the hard segment and the soft segment, a polystyrene / polybutadiene combination or a polystyrene / polyisoprene combination is preferable. In addition, the soft segment is preferably hydrogenated in order to suppress an unintended cross-linking reaction of the thermoplastic elastomer.

The number average molecular weight of the polymer (polystyrene) forming the hard segment is preferably 5000 to 500000, more preferably 1000 to 20000.
The number average molecular weight of the polymer forming the soft segment is preferably 5000 to 1,000,000, more preferably 1000 to 8,000,000, and even more preferably 30,000 to 500000. Further, the volume ratio (x: y) of the hard segment (x) and the soft segment (y) is preferably 5:95 to 80:20, more preferably 10:90 to 70:30, from the viewpoint of moldability. ..

Polystyrene-based thermoplastic elastomers can be synthesized by copolymerizing a polymer forming a hard segment and a polymer forming a soft segment by a known method.
Examples of polystyrene-based thermoplastic elastomers include styrene-butadiene-based copolymers [SBS (polystyrene-poly (butylene) block-polystyrene), SEBS (polystyrene-poly (ethylene / butylene) block-polystyrene)], and styrene-isoprene. Copolymers (polystyrene-polyisoprene block-polystyrene), styrene-propylene-based copolymers [SEP (polystyrene- (ethylene / propylene) block), SEPS (polystyrene-poly (ethylene / propylene) block-polystyrene), SEEPS ( Polystyrene-poly (polystyrene-ethylene / propylene) block-polystyrene), SEB (polystyrene (ethylene / butylene) block)] and the like can be mentioned.

Commercially available polystyrene-based thermoplastic elastomers include, for example, the "Tough Tech" series manufactured by Asahi Kasei Corporation (for example, H1031, H1041, H1043, H1051, H1052, H1053, H1062, H1082, H1141, H1221, H1272, etc.). The "SEBS" series (8007, 8076, etc.) and "SEPS" series (2002, 2063, etc.) manufactured by Kuraray Co., Ltd. can be used.

(Polyurethane thermoplastic elastomer)
As the polyurethane-based thermoplastic elastomer, for example, at least polyurethane forms a hard segment in which pseudo-crosslinks are formed by physical aggregation, and other polymers form a soft segment which is amorphous and has a low glass transition temperature. Examples of materials are available.
Specific examples of the polyurethane-based thermoplastic elastomer include the polyurethane-based thermoplastic elastomer (TPU) specified in JIS K6418: 2007. The polyurethane-based thermoplastic elastomer can be represented as a copolymer containing a soft segment containing a unit structure represented by the following formula A and a hard segment containing a unit structure represented by the following formula B.

In the formula, P represents a long-chain aliphatic polyether or a long-chain aliphatic polyester. R represents an aliphatic hydrocarbon, an alicyclic hydrocarbon, or an aromatic hydrocarbon. P'represents a short chain aliphatic hydrocarbon, an alicyclic hydrocarbon, or an aromatic hydrocarbon.

As the long-chain aliphatic polyether or the long-chain aliphatic polyester represented by P in the formula A, for example, those having a molecular weight of 500 to 5000 can be used. P is derived from a diol compound containing a long-chain aliphatic polyether represented by P and a long-chain aliphatic polyester. Examples of such diol compounds include polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, poly (butylene adipate) diol, poly-ε-caprolactone diol, and poly (hexamethylene carbonate) having a molecular weight within the above range. Examples thereof include diols and ABA-type triblock polyethers.
These can be used alone or in combination of two or more.

In formulas A and B, R is a partial structure introduced using a diisocyanate compound containing an aliphatic hydrocarbon represented by R, an alicyclic hydrocarbon, or an aromatic hydrocarbon. Examples of the aliphatic diisocyanate compound containing an aliphatic hydrocarbon represented by R include 1,2-ethylene diisocyanate, 1,3-propylene diisocyanate, 1,4-butane diisocyanate, and 1,6-hexamethylene diisocyanate. Can be mentioned.
Examples of the diisocyanate compound containing an alicyclic hydrocarbon represented by R include 1,4-cyclohexanediisocyanate and 4,4-cyclohexanediisocyanate. Further, examples of the aromatic diisocyanate compound containing an aromatic hydrocarbon represented by R include 4,4'-diphenylmethane diisocyanate and tolylene diisocyanate.
These can be used alone or in combination of two or more.

In the formula B, as the short-chain aliphatic hydrocarbon represented by P', the alicyclic hydrocarbon, or the aromatic hydrocarbon, for example, those having a molecular weight of less than 500 can be used. Further, P'is derived from a diol compound containing a short-chain aliphatic hydrocarbon represented by P', an alicyclic hydrocarbon, or an aromatic hydrocarbon. Examples of the aliphatic diol compound containing a short-chain aliphatic hydrocarbon represented by P'include glycols and polyalkylene glycols, and specifically, ethylene glycol, propylene glycol, trimethylene glycol, 1,4. -Butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10- Examples thereof include decanediol.
Examples of the alicyclic diol compound containing an alicyclic hydrocarbon represented by P'include cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,3-diol, and the like. Cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol and the like can be mentioned.
Further, examples of the aromatic diol compound containing an aromatic hydrocarbon represented by P'include hydroquinone, resorcin, chlorohydroquinone, bromohydroquinone, methylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4,4'-. Dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenylsulfide, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxydiphenylmethane, bisphenol A, 1, Examples thereof include 1-di (4-hydroxyphenyl) cyclohexane, 1,2-bis (4-hydroxyphenoxy) ethane, 1,4-dihydroxynaphthalin, and 2,6-dihydroxynaphthalin.
These can be used alone or in combination of two or more.

The number average molecular weight of the polymer (polyurethane) forming the hard segment is preferably 300 to 1500 from the viewpoint of melt moldability. The number average molecular weight of the polymer forming the soft segment is preferably 500 to 20000, more preferably 500 to 5000, and particularly preferably 500 to 3000, from the viewpoint of flexibility and thermal stability of the polyurethane-based thermoplastic elastomer. .. The mass ratio (x: y) of the hard segment (x) and the soft segment (y) is preferably 15:85 to 90:10, more preferably 30:70 to 90:10, from the viewpoint of moldability. ..

The polyurethane-based thermoplastic elastomer can be synthesized by copolymerizing a polymer forming a hard segment and a polymer forming a soft segment by a known method. As the polyurethane-based thermoplastic elastomer, for example, the thermoplastic polyurethane described in JP-A-5-331256 can be used.

As the polyurethane-based thermoplastic elastomer, specifically, a combination of a hard segment composed of an aromatic diol and an aromatic diisocyanate and a soft segment composed of a polycarbonate ester is preferable, and more specifically, tolylene diisocyanate (more specifically, tolylene diisocyanate ( TDI) / polyester-based polyol copolymer, TDI / polyether-based polyol copolymer, TDI / caprolactone-based polyol copolymer, TDI / polycarbonate-based polyol copolymer, 4,4'-diphenylmethane diisocyanate (MDI) / polyester Selected from the group consisting of based polyol copolymers, MDI / polyether polyol copolymers, MDI / caprolactone-based polyol copolymers, MDI / polycarbonate-based polyol copolymers, and MDI + hydroquinone / polyhexamethylene carbonate copolymers. At least one of them is preferable, TDI / polyester-based polyol copolymer, TDI / polyether-based polyol copolymer, MDI / polyester polyol copolymer, MDI / polyether-based polyol copolymer, and MDI + hydroquinone / polyhexa. At least one selected from the group consisting of methylene carbonate copolymers is more preferable.

Examples of commercially available polyurethane-based thermoplastic elastomers include BASF's "Elastran" series (for example, ET680, ET880, ET690, ET890, etc.) and Kuraray Co., Ltd.'s "Chramiron U" series (for example). , 2000 series, 3000 series, 8000 series, 9000 series, etc.), "Milactran" series manufactured by Nippon Miractran Co., Ltd. (for example, XN-2001, XN-2004, P390RSUP, P480RSUI, P26MRNAT, E490, E590, P890, etc.) Etc. can be used.

(Polyolefin-based thermoplastic elastomer)
As the polyolefin-based thermoplastic elastomer, for example, at least polyolefin forms a crystalline hard segment having a high melting point, and other polymers (for example, polyolefin, other polyolefin, polyvinyl compound, etc.) are amorphous and have a glass transition temperature. Examples include materials forming low soft segments. Examples of the polyolefin forming the hard segment include polyethylene, polypropylene, isotactic polypropylene, polybutene and the like.

Examples of the polyolefin-based thermoplastic elastomer include an olefin-α-olefin random copolymer, an olefin block copolymer, and the like, and specific examples thereof include a propylene block copolymer, an ethylene-propylene copolymer, and a propylene-. 1-hexene copolymer, propylene-4-methyl-1pentene copolymer, propylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-pentene copolymer, ethylene- 1-butene copolymer, 1-butene-1-hexene copolymer, 1-butene-4-methyl-pentene, ethylene-methacrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate Copolymer, ethylene-butyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, propylene-methacrylate copolymer, propylene-methyl methacrylate copolymer Copolymer, propylene-ethyl methacrylate copolymer, propylene-butyl methacrylate copolymer, propylene-methyl acrylate copolymer, propylene-ethyl acrylate copolymer, propylene-butyl acrylate copolymer, ethylene-vinyl acetate Examples thereof include a copolymer and a propylene-vinyl acetate copolymer.

Among these, as the polyolefin-based thermoplastic elastomer, a propylene block copolymer, an ethylene-propylene copolymer, a propylene-1-hexene copolymer, a propylene-4-methyl-1pentene copolymer, and a propylene-1- Butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-pentene copolymer, ethylene-1-butene copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer , Ethylene-ethyl methacrylate copolymer, ethylene-butyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, propylene-methacrylate copolymer , Propropylene-methyl methacrylate copolymer, propylene-ethyl methacrylate copolymer, propylene-butyl methacrylate copolymer, propylene-methyl acrylate copolymer, propylene-ethyl acrylate copolymer, propylene-butyl acrylate copolymer At least one selected from the group consisting of coalescing, ethylene-vinyl acetate copolymer, and propylene-vinyl acetate copolymer is preferable, and ethylene-propylene copolymer, propylene-1-butene copolymer, and ethylene-1- At least one selected from the group consisting of a butene copolymer, an ethylene-methyl methacrylate copolymer, an ethylene-methyl acrylate copolymer, an ethylene-ethyl acrylate copolymer, and an ethylene-butyl acrylate copolymer is more preferable. ..
Further, two or more kinds of olefin resins such as ethylene and propylene may be used in combination. The content of the olefin resin in the polyolefin-based thermoplastic elastomer is preferably 50% by mass or more and 100% by mass or less.

The number average molecular weight of the polyolefin-based thermoplastic elastomer is preferably 5000 to 10000000. When the number average molecular weight of the polyolefin-based thermoplastic elastomer is 5000 to 1000000, the mechanical properties of the thermoplastic resin material are sufficient, and the processability is also excellent. From the same viewpoint, the number average molecular weight of the polyolefin-based thermoplastic elastomer is more preferably 7,000 to 1,000,000, and particularly preferably 1,000 to 1,000,000. Thereby, the mechanical physical characteristics and workability of the thermoplastic resin material can be further improved. The number average molecular weight of the polymer forming the soft segment is preferably 200 to 6000 from the viewpoint of toughness and low temperature flexibility. Further, the mass ratio (x: y) of the hard segment (x) and the soft segment (y) is preferably 50:50 to 95:15, more preferably 50:50 to 90:10, from the viewpoint of moldability. ..
The polyolefin-based thermoplastic elastomer can be synthesized by copolymerizing by a known method.

Further, as the polyolefin-based thermoplastic elastomer, one obtained by acid-modifying the polyolefin-based thermoplastic elastomer may be used.
"A product obtained by acid-modifying a polyolefin-based thermoplastic elastomer" means a polyolefin-based thermoplastic elastomer in which an unsaturated compound having an acidic group such as a carboxylic acid group, a sulfate group, or a phosphoric acid group is bonded.
To bond an unsaturated compound having an acidic group such as a carboxylic acid group, a sulfuric acid group, or a phosphoric acid group to a polyolefin-based thermoplastic elastomer, for example, as an unsaturated compound having an acidic group to a polyolefin-based thermoplastic elastomer. It is possible to bond (for example, graft polymerization) an unsaturated bond site of an unsaturated carboxylic acid (generally maleic anhydride).
As the unsaturated compound having an acidic group, an unsaturated compound having a carboxylic acid group, which is a weak acid group, is preferable from the viewpoint of suppressing deterioration of the polyolefin-based thermoplastic elastomer. Examples of unsaturated compounds having a carboxylic acid group include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid and the like.

Commercially available products of polyolefin-based thermoplastic elastomers include, for example, the "Toughmer" series manufactured by Mitsui Chemicals, Inc. (for example, A0550S, A1050S, A4050S, A1070S, A4070S, A35070S, A1085S, A4085S, A7090, A70090, MH7007, MH7010. , XM-7070, XM-7080, BL4000, BL2481, BL3110, BL3450, P-0275, P-0375, P-0775, P-0180, P-0280, P-0480, P-0680, etc.), Mitsui Dupont "Nucrel" series manufactured by Polychemical Co., Ltd. (for example, AN4214C, AN4225C, AN42115C, N0903HC, N0908C, AN42012C, N410, N1050H, N1108C, N1110H, N1207C, N1214, AN4221C, N1525, N1560, N0200H, AN42 N035C), etc., "Elvalois AC" series (for example, 1125AC, 1209AC, 1218AC, 1609AC, 1820AC, 1913AC, 2112AC, 2116AC, 2615AC, 2715AC, 3117AC, 3427AC, 3717AC, etc.), Sumitomo Chemical Co., Ltd. "Aklift" series , "Evertate" series, etc., "Ultrasen" series manufactured by Toso Co., Ltd., "Prime TPO" series made of prime polymer (for example, E-2900H, F-3900H, E-2900, F-3900, J- 5900, E-2910, F-3910, J-5910, E-2710, F-3710, J-5910, E-2740, F-3740, R110MP, R110E, T310E, M142E, etc.) can also be used.

-Thermoplastic resin-
(Polyester-based thermoplastic resin)
Examples of the polyester-based thermoplastic resin include polyesters that form the hard segments of the polyester-based thermoplastic elastomer described above.
Specific examples of the polyester-based thermoplastic resin include polylactic acid, polyhydroxy-3-butylbutyric acid, polyhydroxy-3-hexylbutyric acid, poly (ε-caprolactone), polyenant lactone, polycapryrolactone, and polybutylene. Examples thereof include aliphatic polyesters such as adipate and polyethylene adipate, aromatic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and polybutylene naphthalate. Among these, polybutylene terephthalate is preferable as the polyester-based thermoplastic resin from the viewpoint of heat resistance and processability.

Commercially available polyester-based thermoplastic resins include, for example, the "Juranex" series manufactured by Polyplastics Co., Ltd. (for example, 2000, 2002, etc.) and the "Novaduran" series manufactured by Mitsubishi Engineering Plastics Co., Ltd. (for example, 5010R5). , 5010R3-2, etc.), "Trecon" series manufactured by Toray Industries, Inc. (for example, 1401X06, 1401X31, etc.) and the like can be used.

(Polyamide-based thermoplastic resin)
Examples of the polyamide-based thermoplastic resin include polyamides that form hard segments of the above-mentioned polyamide-based thermoplastic elastomers.
Specific examples of the polyamide-based thermoplastic resin include a polyamide obtained by ring-opening polycondensation of ε-caprolactam (amide 6), a polyamide obtained by ring-opening polycondensation of undecanlactam (amide 11), and a ring-opening polycondensation of lauryl lactam. Examples thereof include polyamide (amide 12), polyamide (amide 66) obtained by polycondensing diamine and dibasic acid, and polyamide (amide MX) having metaxylene diamine as a constituent unit.

The amide 6 can be represented by, for example, {CO- (CH ₂ ) _5- NH} _n. The amide 11 can be represented by, for example, {CO- (CH ₂ ) _10- NH} _n. The amide 12 can be represented by, for example, {CO- (CH ₂ ) _11- NH} _n. The amide 66 can be represented by, for example, {CO (CH ₂ ) ₄ CONH (CH ₂ ) ₆ NH} _n . The amide MX can be represented by, for example, the following structural formula (A-1). Here, n represents the number of repeating units.

As a commercially available product of amide 6, for example, the "UBE nylon" series (for example, 1022B, 1011FB, etc.) manufactured by Ube Industries, Ltd. can be used. As a commercially available product of amide 11, for example, the "Rilsan B" series manufactured by Arkema Co., Ltd. can be used. As a commercially available product of amide 12, for example, the "UBE nylon" series manufactured by Ube Industries, Ltd. (for example, 3024U, 3020U, 3014U, etc.) can be used. As a commercially available product of amide 66, for example, the "Leona" series manufactured by Asahi Kasei Corporation (for example, 1300S, 1700S, etc.) can be used. As a commercially available product of amide MX, for example, "MX nylon" series manufactured by Mitsubishi Gas Chemical Company, Inc. (for example, S6001, S6021, S6011, etc.) can be used.

The polyamide-based thermoplastic resin may be a homopolymer formed only by the above-mentioned structural units, or may be a copolymer of the above-mentioned structural units and other monomers. In the case of a copolymer, the content of the structural unit in each polyamide-based thermoplastic resin is preferably 40% by mass or more.

(Polyolefin-based thermoplastic resin)
Examples of the polyolefin-based thermoplastic resin include polyolefins that form hard segments of the above-mentioned polyolefin-based thermoplastic elastomer.
Specific examples of the polyolefin-based thermoplastic resin include polyethylene-based thermoplastic resins, polypropylene-based thermoplastic resins, and polybutadiene-based thermoplastic resins. Among these, polypropylene-based thermoplastic resin is preferable as the polyolefin-based thermoplastic resin from the viewpoint of heat resistance and processability.
Specific examples of the polypropylene-based thermoplastic resin include propylene homopolymers, propylene-α-olefin random copolymers, propylene-α-olefin block copolymers, and the like. Examples of the α-olefin include propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, and the like. Examples thereof include α-olefins having about 3 to 20 carbon atoms such as 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene.

-Other ingredients-
In addition to the resin, the resin material may contain other components such as additives as long as the effect is not impaired. Examples of other components include rubber, various fillers (for example, silica, calcium carbonate, clay, etc.), anti-aging agents, oils, plasticizers, color formers, weather resistant agents, and the like.

<Making tires>
Next, an example of a method for manufacturing the tire 10 will be described.
First, an unvulcanized inner liner 16, an unvulcanized side reinforcing rubber 24, a carcass 14 containing an unvulcanized rubber material, a bead core 26, and a bead filler 28 are placed on the outer periphery of a known tire forming drum (not shown). Form an unvulcanized tire case with.

On the other hand, the belt layer 40 is formed as follows.
Specifically, the resin coating cord 42 is sent out toward the outer peripheral surface of the belt forming drum (not shown). The resin coating cord 42 is heated by hot air and pressed against the outer peripheral surface of the belt forming drum in a state where the coating resin 42S is melted, and then cooled. In this way, the resin coating cord 42 is spirally wound around the outer peripheral surface of the belt forming drum and pressed against the outer peripheral surface to form a layer of the resin coating cord 42 on the outer peripheral surface of the belt forming drum.

Next, the belt layer 40 in which the resin coating cord 42 is cooled and the coating resin 42S is solidified is removed from the belt forming drum. Then, after applying an adhesive to the inner peripheral surface of the removed belt layer 40 as needed, the belt layer 40 is arranged on the radial outer side of the unvulcanized tire case in the tire forming drum. After that, the unvulcanized tire case is expanded, and the outer peripheral surface of the tire case, that is, the outer peripheral surface of the carcass 14, is crimped to the inner peripheral surface of the belt layer 40.
Finally, an adhesive is applied to the outer peripheral surface of the belt layer 40, if necessary, and then the unvulcanized tread 20 is attached to complete the raw tire.
The raw tire produced in this manner is vulcanized and molded by a vulcanization molding mold to complete the tire 10.

Although an example of the embodiment in the present disclosure has been described above, the present disclosure is not limited to these embodiments, and various other embodiments are possible.

In addition, one embodiment of the present disclosure includes the following aspects.
<1> A pair of bead cores and
A carcass straddling the pair of bead cores and having an end locked to the bead core,
An inner liner provided on the inner surface side of the tire of the carcass, wherein the content of diene rubber is 20% by mass or more with respect to the total amount of rubber contained in the inner liner.
A side reinforcing rubber layer provided in direct contact with the inner liner between the carcass and the inner liner of the tire side portion and extending in the tire radial direction along the inner surface of the carcass.
A belt layer provided on the outer side of the carcass in the tire radial direction and having a cord and a cord coating layer covering the cord and containing a resin.
A tread provided on the outer side of the belt layer in the tire radial direction and
Run-flat tires equipped with.
<2> The run-flat tire according to <1>, wherein the diene rubber contained in the inner liner contains natural rubber.
<3> The run-flat tire according to <1> or <2>, wherein the inner liner further contains a butyl rubber.
<4> The run-flat tire according to any one of <1> to <3>, wherein the side reinforcing rubber layer contains a diene rubber.
<5> The run-flat according to any one of <1> to <4>, which is arranged so as to extend from the bead core to the outside in the tire radial direction along the outer surface of the carcass and further includes a bead filler containing a resin. tire.
<6> The run-flat tire according to any one of <1> to <5>, wherein the bead core has a bead wire and a bead coating layer that covers the bead wire and contains a resin.

Hereinafter, the present disclosure will be specifically described with reference to Examples, but the present disclosure is not limited to these descriptions. Unless otherwise specified, "part" represents a mass standard.

[Example 1]
<Manufacturing of coated resin cord>
An adhesive (manufactured by Mitsubishi Chemical Co., Ltd.) that is heat-melted on a multifilament with an average diameter of φ1.15 mm (a monofilament with an average diameter of φ0.35 mm (steel, strong: 280N, elongation: 3%), twisted with 7 strands). , Maleic anhydride-modified polyester-based thermoplastic elastomer, product name: Primaloy-AP GQ730) is attached. Next, a coating resin (manufactured by Toray DuPont, polyester-based thermoplastic elastomer, product name: Hytrel 5557) extruded by an extruder is adhered to the outer periphery thereof, coated, and cooled. The extrusion conditions are such that the temperature of the metal member is 200 ° C., the temperature of the coating resin is 240 ° C., and the extrusion speed is 30 m / min. As described above, the coated resin cord is produced.

<Preparation of unvulcanized inner liner>
The following components are kneaded with a Bambari mixer (Mixtron BB MIXER, manufactured by Kobe Steel, Ltd.) and molded into a sheet shape to prepare an unvulcanized inner liner.
-Natural rubber ("NR (PHR)" in Table 1): RSS # 3 ... 20 parts by mass-Bromobutyl rubber ("Br-IIR (PHR)" in Table 1, Bromobutyl 2225 trademark: manufactured by Exxon)・ ・ ・ 80 parts by mass ・ Carbon black N660 (trademark: manufactured by Degissa) ・ ・ ・ 45 parts by mass ・ Flat clay (POLYFIL DL trademark: manufactured by JH Huber) ・ ・ ・ 30 parts by mass ・ Process oil (aroma oil AROMAX) # 1 Trademark: Made by Fujikosan Co., Ltd.) ・ ・ ・ 2 parts by mass

<Making unvulcanized side reinforcing rubber>
The following components are kneaded and molded with a Bambari mixer (Mixtron BB MIXER, manufactured by Kobe Steel, Ltd.) to prepare unvulcanized side reinforcing rubber.
・ Natural rubber: RSS # 3 ・ ・ ・ 25 parts by mass ・ butadiene rubber (BR): BR502, manufactured by JSR ・ ・ ・ 75 parts by mass ・ Carbon black: FEF, manufactured by Asahi Carbon Co. ・ ・ ・ 60 parts by mass ・ Anti-aging Agent: Antigen 6C, manufactured by Sumitomo Chemical Co., Ltd .: 2 parts by mass, vulcanization accelerator: Noxeller NS-P, manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd .... 3 parts by mass, vulcanization accelerator: Noxeller TOT-N, Made by Ouchi Shinko Kagaku Kogyo Co., Ltd .: 2 parts by mass, sulfur: 5 parts by mass

<Preparation of unvulcanized tread>
The following components are kneaded with a Bambari mixer (Mixtron BB MIXER, manufactured by Kobe Steel, Ltd.) and molded into a sheet shape to prepare an unvulcanized tread.
-Natural rubber: RSS # 3 ... 50 parts by mass-Styrene-butadiene copolymer rubber (SBR): # 1500 (vulcanized polymer SBR), manufactured by JSR ... 50 parts by mass-Carbon black: ISAF, Asahi carbon Made by 50 parts by mass, anti-aging agent: Antigen 6C, manufactured by Sumitomo Chemical Co., Ltd .... 1 part by mass, vulcanization accelerator: Noxeller CZ, manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd .... -Vulcanization accelerator: Noxeller DM, manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd .... 1 part by mass-Vulcanization accelerator: Noxeller D, manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd .... 0.5 parts by mass-Sulcanization ...・ 1.5 parts by mass

<Making tires>
An unvulcanized tire case and belt layer are made according to the above-described embodiment.
As the bead core, as shown in FIG. 2, one steel wire (φ2.1 mm) coated with a coating resin (polyester-based thermoplastic elastomer, manufactured by Toray DuPont, product name: Hytrel 5557) is wound. Use the one that has been used. Further, as the bead filler, a bead filler made of a polyester-based thermoplastic elastomer (manufactured by Toray DuPont, product name: Hytrel 5557) is used. As the carcass, an organic fiber cord coated with diene rubber (natural rubber) is used.
The belt layer is installed on the outer peripheral surface of the unvulcanized tire case, and the unvulcanized tread is wrapped around the outer periphery of the belt layer to obtain a raw tire. Then, the obtained raw tire is vulcanized by heating at 160 ° C. for 20 minutes to obtain a tire.

<Evaluation>
(Run flat running performance (durability) evaluation)
In the indoor drum test based on the ISO standard, run flat running is performed at an internal pressure of 0 kPa and a speed of 80 km / h. The mileage until the vehicle becomes impossible to travel due to a tire failure or a support failure is measured, and an index is obtained when the mileage in Comparative Example 1 is 100. The results are shown in Table 1. The larger the index, the better the run-flat running performance (that is, durability).

(Evaluation of internal pressure retention)
The tire obtained by assembling the molded tire with a rim and filling the tire with air so that the internal pressure becomes 0.3 MPa is left in a constant temperature and humidity chamber for 3 months while being held in an environment of 40 ° C./50% RH. do. The internal pressure retention rate is obtained from the ratio of the internal pressure after standing to the internal pressure before standing, and the index when the internal pressure holding rate in Comparative Example 1 is 100 is obtained. The results are shown in Table 1. The larger the index, the better the internal pressure retention.

[Example 2]
In the production of the unvulcanized inner liner, the tire is produced and evaluated in the same manner as in Example 1 except that the amount of natural rubber added is 50 parts by mass and the amount of bromobutyl rubber added is 50 parts by mass.

[Example 3]
In the production of the unvulcanized inner liner, the tire is produced and evaluated in the same manner as in Example 1 except that the amount of natural rubber added is 80 parts by mass and the amount of bromobutyl rubber added is 20 parts by mass.

[Comparative Example 1]
In the production of the coated resin cord, coated rubber (natural rubber) is used instead of the coated resin, and in the production of the unvulcanized inner liner, the amount of natural rubber added is 0 parts by mass and the amount of bromobutyl rubber added is 100 parts by mass. Then, the tire is manufactured and evaluated in the same manner as in Example 1 except that a coated rubber (natural rubber) is used instead of the coating resin in the bead core and a bead filler made of rubber (natural rubber) is used as the bead filler.

[Comparative Example 2]
In the production of the coated resin cord, the tire is used in the same manner as in Example 1 except that the coated rubber is used instead of the coated resin, the coated rubber is used instead of the coated resin in the bead core, and the bead filler made of rubber is used as the bead filler. Is produced and evaluated.

[Comparative Example 3]
In the production of the coated resin cord, the tire is used in the same manner as in Example 2 except that the coated rubber is used instead of the coated resin, the coated rubber is used instead of the coated resin in the bead core, and the bead filler made of rubber is used as the bead filler. Is produced and evaluated.

The numerical values of the durability evaluation and the internal pressure retention evaluation shown in Table 1 above are both predicted data by simulation.

The disclosure of Japanese Patent Application No. 2018-210297 filed on November 8, 2018 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards described herein are to the same extent as if the individual documents, patent applications, and technical standards were specifically and individually stated to be incorporated by reference. Incorporated herein.

The description of the code is as follows.
10 ... tires (run-flat tires), 12 ... bead part, 14 ... carcass, 16 ... inner liner, 18 ... tread part, 20 ... tread, 22 ... tire side part, 24 ... side reinforcing rubber, 26 ... bead core, 28 ... Bead filler, 30 ... rim, 40 ... belt layer, 42 ... resin coated cord

Claims (6)

With a pair of bead cores
A carcass straddling the pair of bead cores and having an end locked to the bead core,
An inner liner provided on the inner surface side of the tire of the carcass, wherein the content of diene rubber is 20% by mass or more with respect to the total amount of rubber contained in the inner liner.
A side reinforcing rubber layer provided in direct contact with the inner liner between the carcass and the inner liner of the tire side portion and extending in the tire radial direction along the inner surface of the carcass.
A belt layer provided on the outer side of the carcass in the tire radial direction and having a cord and a cord coating layer covering the cord and containing a resin.
A tread provided on the outer side of the belt layer in the tire radial direction and
Run-flat tires equipped with. The run-flat tire according to claim 1, wherein the diene rubber contained in the inner liner contains natural rubber. The run-flat tire according to claim 1 or 2, wherein the inner liner further includes a butyl rubber. The run-flat tire according to any one of claims 1 to 3, wherein the side reinforcing rubber layer includes a diene rubber. The run-flat tire according to any one of claims 1 to 4, which is arranged so as to extend from the bead core outward in the radial direction of the tire along the outer surface of the carcass and further includes a bead filler containing a resin. The run-flat tire according to any one of claims 1 to 5, wherein the bead core has a bead wire and a bead coating layer that covers the bead wire and contains a resin.

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