Tire with storage body

Abstract

To provide a tire which includes a storage body that can store a functional component having a sensor function for detecting tire information and is excellent in durability, on a tire inner surface of a tread part.SOLUTION: A tire with a storage body includes a storage body capable of storing a functional component having a sensor function for detecting tire information so as to have a contact surface contacting a tire inner surface of a tread part, on the tire inner surface, wherein the storage body is composed of a rubber component containing 35 mass% or more of natural rubber (NR), and contains 10 to 85 pts.mass of carbon black with respect to 100 pts.mass of the rubber component, and has elongation at break (EB) at 20°C of the storage body of 150% or more and tensile stress (M100) at elongation of 100% at 100°C of 5.0 MPa or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a tire having a housing on the inner surface of the tire that can accommodate a functional component having a sensor function for detecting tire information.

Background Art

[0002] In order to detect tire information, functional components having a sensor function (such as electronic components such as sensor units) are disposed in tires. In particular, due to ease of detecting air pressure and wear, such functional components are disposed on the inner surface of the tread portion of the tire (for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, the housing for accommodating the functional component disposed on the inner surface of the tread portion of the tire is likely to be subjected to forces due to the rotation of the tire during running and impacts from the road surface, etc., and thus there are problems in terms of durability. And, Patent Documents 1 and 2 disclose tires in which peeling from the tire surface of an electronic component mounting member (housing), etc. hardly occurs even when a large impact is applied during high-speed running or during high-speed running in a low-temperature environment, but these have room for improvement due to limitations on the rubber physical properties of the members constituting the tire and the mounting position of the electronic component mounting member (housing).

[0005] Therefore, an object of the present invention is to provide a tire having a container on the inner surface of the tread portion of the tire that can accommodate a functional component having a sensor function for detecting tire information and has excellent durability. **Means for Solving the Problems**

[0006] In order to solve the above problems, the present inventor has intensively studied and provided a container on the inner surface of the tread portion of the tire that can accommodate a functional component having a sensor function for detecting tire information so as to have a contact surface that contacts the inner surface of the tire. This container is composed of a rubber component containing 35% by mass or more of natural rubber (NR), and further contains 10 to 85 parts by mass of carbon black with respect to 100 parts by mass of this rubber component. The tire in which the elongation at break (EB) at 20°C of this container is 150% or more and the tensile stress at 100% elongation (M100) at 100°C is 5.0 MPa or less has excellent durability of the container provided on the inner surface of the tread portion of the tire. Based on this finding, the present invention has been completed.

[0007] That is, the present invention is as follows <1> to <8>. <1> A tire provided with a container on the inner surface of the tread portion of the tire that can accommodate a functional component having a sensor function for detecting tire information so as to have a contact surface that contacts the inner surface of the tire, wherein the container is composed of a rubber component containing 35% by mass or more of natural rubber (NR), and further contains 10 to 85 parts by mass of carbon black with respect to 100 parts by mass of the rubber component, and the elongation at break (EB) at 20°C of the container is 150% or more and the tensile stress at 100% elongation (M100) at 100°C is 5.0 MPa or less. <2> The tire according to <1>, wherein the EB and the M100 of the container satisfy the relationship of the following formula (1). (1) 1000 ≧ 275 × M100 - EB <3> The tire according to <1> or <2>, wherein the average value of the nitrogen adsorption specific surface area (N 2 SA) of the carbon black is 60 m 2 / g or less. <4>The tire according to any one of <1> to <3>, wherein the content of the vulcanizing agent with respect to 100 parts by mass of the rubber component is 3.5 parts by mass or less. <5>The tire according to any one of <1> to <4>, wherein M100 is 1.3 MPa or more. <6>The tire according to any one of <1> to <5>, wherein the container is fixed to the inner surface of the tire, and the functional component is housed in the container so as to have a contact surface that contacts the inner surface of the tire. <7>The tire according to <6>, wherein the container is fixed to the inner surface of the tire by an adhesive. <8>The tire according to any one of <1> to <7>, wherein the sensor function of the functional component is a sensor function using a piezoelectric element as a sensor element.

Advantages of the Invention

[0008] According to the present invention, it is possible to obtain a tire provided with a container on the inner surface of the tread portion of the tire, which can accommodate a functional component having a sensor function for detecting tire information and has excellent durability.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0010] The present invention will be described. The present invention provides a tire having a container capable of accommodating a functional component having a sensor function for detecting tire information on the inner surface of the tread portion in contact with the inner surface of the tire. The container is made of a rubber component containing 35% by mass or more of natural rubber (NR), and further contains 10 to 85 parts by mass of carbon black with respect to 100 parts by mass of the rubber component. The tire has an elongation at break (EB) of 150% or more at 20°C and a tensile stress at 100% elongation (M100) of 5.0 MPa or less at 100°C. Hereinafter, this will also be referred to as "the tire of the present invention".

[0011] In the present invention, the numerical range represented by "~" means a numerical range in which the numerical value described before "~" is the lower limit value and the numerical value described after "~" is the upper limit value, unless otherwise specified.

[0012] Hereinafter, the configuration of the container provided in the tire of the present invention, the constituent components and their contents, and the configuration of the tire of the present invention (as a whole) will be described in detail with reference to the drawings. Note that the dimensional ratios (length, thickness, etc.) and orientations of each member shown in the drawings may be different from the actual dimensional ratios and orientations in order to facilitate understanding of the invention. In some cases, some reference signs may be omitted.

[0013] [Container] The container provided in the tire of the present invention is made of a predetermined rubber component. The container is provided on the inner surface of the tread portion of the tire and can accommodate a functional component having a sensor function for detecting tire information so as to have a contact surface that contacts the inner surface of the tire. For example, as shown in FIGS. 1 to 3, the base portion 31 of the container 30 is joined and fixed to the inner surface 12 of the tread portion 1 of the tire (the inner surface 12 joined to the base portion 31 is omitted in FIGS. 2 and 3). The accommodating portion 33 can accommodate the functional component 20 so as to be surrounded by the side wall 32. Further, an embodiment is shown in which the functional component 20 accommodated here can have a contact surface 21 that contacts the inner surface 12 of the tread portion 1 via the base portion 31.

[0014] Here, when the housing is "provided on the inner surface of the tire tread portion", it means that the housing is connected and arranged on the inner surface of the tire tread portion (the inner circumferential surface of the tire at a position facing the tread surface of the tread portion). Further, when the functional component has a contact surface "contacting the inner surface of the tire (of the tread portion)", it includes not only the embodiment in which the functional component has a contact surface directly contacting the inner surface of the tire tread portion, but also the embodiment in which the functional component contacts through a member (base portion 31 in the embodiment of FIG. 1) that is in surface contact with the inner surface of the tire tread portion in the housing. That is, the embodiment in which the functional component is in direct surface contact with the inner surface of the tire tread portion, and the embodiment in which the functional component is in surface contact through a member that is in surface contact with the inner surface of the tire tread portion in the housing are included.

[0015] And it is more preferable that this housing is fixed to the inner surface of the tire tread portion (in a state where the position of the housing does not substantially change), and it is suitable that the functional component is accommodated in this fixed housing so as to have a contact surface contacting the inner surface of the tire tread portion. Further, it is more preferable that this is an embodiment in which the housing is fixed to the inner surface of the tire tread portion by an adhesive. As this adhesive, an epoxy-based adhesive, an acrylic-based adhesive, etc. can be used. Also, a double-sided tape or the like may be used as the adhesive.

[0016] Hereinafter, details of each component included in this housing, physical properties of this housing, etc. will be described.

[0017] <Rubber component> The container provided in the tire of the present invention is composed of a rubber component containing 35% by mass or more of natural rubber (NR). That is, this container is composed of a rubber component, and this rubber component contains 35% by mass or more of natural rubber (NR). As long as this rubber component contains natural rubber (NR) at a content ratio of 35% by mass or more, there are no particular restrictions otherwise, and any known rubber component used (used in combination) for applications constituting rubber products such as diene rubbers can be used. As diene rubbers, in addition to the above-mentioned natural rubber (NR), for example, butadiene rubber (BR), styrene-butadiene copolymer rubber (styrene butadiene rubber, SBR), acrylonitrile-butadiene copolymer rubber (nitrile rubber, NBR), chloroprene rubber (CR), synthetic isoprene rubber (IR), styrene-isoprene copolymer rubber, isoprene-butadiene copolymer rubber, styrene-butadiene-vinylpyridine terpolymer (VP), etc. can be mentioned. In particular, when the rubber component constituting this container contains 35% by mass or more of natural rubber (NR) and contains butadiene rubber (BR), the effects of the present invention are easily exerted, so it is preferable. However, it is also possible to use a rubber component other than diene rubbers such as olefin rubbers (ethylene propylene rubber, acrylic rubber, etc.), fluororubbers, silicone rubbers, and butyl rubber (IIR) in combination.

[0018] In addition, the content ratio of natural rubber (NR) in the rubber component constituting the container provided in the tire of the present invention is more preferably more than 35% by mass, further preferably 40% by mass or more, further preferably 45% by mass or more, further preferably 50% by mass or more, further preferably 55% by mass or more, further preferably 60% by mass or more, further preferably 65% by mass or more, further preferably 70% by mass or more, further preferably 75% by mass or more, since the effects of the present invention are more easily exerted. The upper limit may be 100% by mass, but more preferably 95% by mass or less, further preferably 90% by mass or less, and further preferably 85% by mass or less.

[0019] Furthermore, when the rubber component constituting this container contains butadiene rubber (BR) in addition to natural rubber (NR), the effects of the present invention are more likely to be exhibited. Therefore, in this rubber component, it is more preferable that the content ratio of natural rubber (NR) is higher than the content ratio of butadiene rubber (BR) (NR / BR is more than 1.0). It is even more preferable that the ratio of natural rubber (NR) to butadiene rubber (BR) in this rubber component is 1.5 times or more (NR / BR is 1.5 or more), even more preferably 2 times or more (NR / BR is 2.0 or more), even more preferably 2.5 times or more (NR / BR is 2.5 or more), and even more preferably 3 times or more (NR / BR is 3.0 or more). The upper limit is not particularly limited, and it may be, for example, 20 times or less (NR / BR is 20 or less).

[0020] <Carbon black> The container provided in the tire of the present invention contains carbon black in addition to the above-described predetermined rubber component as a constituent component. This carbon black is not particularly limited, and any known carbon black used in applications such as rubber products can be used. Specific examples of carbon black include those of various grades such as SAF-HS, SAF, ISAF-HS, ISAF, ISAF-LS, IISAF-HS, HAF-HS, HAF, HAF-LS, FEF, GPF, SRF, FT, MT, etc. Recycled carbon black obtained by recycling from used rubber products, etc. can also be used. And this carbon black may be used alone or in combination of two or more. In addition, since it becomes easier to further improve the durability of the container, the average value of the nitrogen adsorption specific surface area (N 2 SA) is more preferably 60 m 2 / g or less, even more preferably 50 m 2 / g or less, and even more preferably 40 m 2 / g or less. That is, it is more suitable that the particle size of the carbon black is larger. The lower limit is more preferably 15 m 2 / g or more, for example, to easily suppress the dropping of the housed functional parts, and 23 m2 It is more preferably / g or more.

[0021] Here, this "carbon black" means carbon fine particles composed of primary particles with a diameter of about 3 to 500 nm industrially manufactured with quality control. Also, the nitrogen adsorption specific surface area (N 2 SA) of the carbon black is a value measured in accordance with JIS K6217-2:2017. Furthermore, the "average value of the nitrogen adsorption specific surface area (N 2 SA) of the carbon black" means the value of the nitrogen adsorption specific surface area (N 2 SA) of the carbon black when using one type alone, and when using two or more types in combination, it is the value obtained by multiplying the value of the nitrogen adsorption specific surface area (N 2 SA) of each carbon black used in combination by its usage ratio and then adding them together. In this calculation, the total of the usage ratios of each carbon black is set to 1.0.

[0022] And in this container, the carbon black is contained in an amount of 10 to 85 parts by mass with respect to 100 parts by mass of the rubber component constituting the container. Furthermore, the content of this carbon black is more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, even more preferably 40 parts by mass or more, and even more preferably 50 parts by mass or more with respect to 100 parts by mass of the rubber component described above. The upper limit is more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less. Note that if the amount of this carbon black is less than 10 parts by mass or more than 85 parts by mass with respect to 100 parts by mass of the rubber component described above, the effects of the present invention may not be obtained. Here, the content of the carbon black in the present invention means the total content of the entire carbon black including recycled carbon black when a plurality of carbon blacks are included.

[0023] <Vulcanizing agent> The container provided in the tire of the present invention preferably contains a vulcanizing agent. Sulfur is typically exemplified as the vulcanizing agent, but as a component other than sulfur, a compound having a crosslinking function between polymers such as a peroxide may also be used. Further, these may be used in combination. Furthermore, together with this vulcanizing agent, a vulcanization accelerator or a vulcanization acceleration aid may be included.

[0024] And, the content of the vulcanizing agent in this container (the total content when two or more are used in combination) is preferably 3.5 parts by mass or less, more preferably 3.0 parts by mass or less, and even more preferably 2.5 parts by mass or less with respect to 100 parts by mass of the rubber component constituting the container, since the effects of the present invention are more likely to be exhibited. The lower limit may be 0.1 part by mass or more, may be 0.5 part by mass or more, may be 1.0 part by mass or more, or may be 1.5 part by mass or more. Furthermore, the content of the vulcanization accelerator in this container is preferably 0.1 to 2.0 parts by mass, more preferably 0.5 to 1.5 parts by mass with respect to 100 parts by mass of the rubber component constituting the container, either as a primary accelerator alone or in a blend with a secondary accelerator.

[0025] <Other components> The container provided in the tire of the present invention may further contain, as optional components, components other than the above-described rubber component, carbon black, vulcanizing agent, vulcanization accelerator, and vulcanization acceleration aid, as long as it does not significantly affect the effects of the present invention. For example, appropriate amounts of various additives generally used in rubber products such as white fillers (such as silica, talc, mica, clay, calcium carbonate, etc.), resin components (such as terpene resin, coumarone resin, indene resin, rosin resin, etc.), zinc oxide (zinc white), oil (such as aroma oil), stearic acid, wax, lecithin, anti-aging agent, and plasticizer can be contained.

[0026] For example, the contents of oil, stearic acid, zinc oxide, and antioxidant in this container are each preferably 0.5 to 10 parts by mass, more preferably 1.0 to 8.0 parts by mass, and even more preferably 1.0 to 5.0 parts by mass with respect to 100 parts by mass of the rubber component constituting the container. In particular, when this container has a configuration in which it contains a relatively large amount of antioxidant (for example, a configuration in which it contains 2 parts by mass or more, and further 2.5 parts by mass or more of antioxidant with respect to 100 parts by mass of the rubber component constituting the container), it is suitable because the durability is more likely to be improved due to the synergistic effect with other configurations.

[0027] <Elongation at break (EB) at 20°C and tensile stress at 100% elongation (M100) at 100°C> The container provided in the tire of the present invention has the configuration as described above. Further, the elongation at break (EB) of this container at 20°C is 150% or more and the tensile stress at 100% elongation (M100) at 100°C is 5.0 MPa or less. With such a configuration, it has durability that can withstand forces, impacts, etc. caused by rotation during tire running. This EB is more preferably 160% or more, even more preferably 180% or more, even more preferably 200% or more, even more preferably 230% or more, even more preferably 250% or more, even more preferably 280% or more, and even more preferably 300% or more. Also, this M100 is more preferably 4.9 MPa or less, even more preferably 4.7 MPa or less, even more preferably 4.5 MPa or less, even more preferably 4.2 MPa or less, even more preferably 4.0 MPa or less, and even more preferably 3.7 MPa or less. The lower limit of this M100 is more preferably 1.0 MPa or more, even more preferably 1.3 MPa or more, and even more preferably 1.5 MPa or more because it is easier to suppress the dropout of the housed functional parts.

[0028] Here, this EB is a value confirmed by a method of collecting a predetermined rubber test piece (such as a dumbbell-shaped No. 7 shape, etc.) from the container, performing a tensile test on this rubber test piece at a tensile speed of 500 mm / min in accordance with JIS K6251:2017, and measuring the elongation at break (elongation rate at break (%): EB) at 20°C. Also, this M100 is a value confirmed by a method of collecting a predetermined rubber test piece (such as a dumbbell-shaped No. 7 shape, etc.) from the container, performing a tensile test on this rubber test piece at a tensile speed of 500 mm / min in accordance with JIS K6251:2017, and measuring the tensile stress at 100% elongation (MPa: M100) at 100°C. And within the range of the above-described configuration, by adjusting the ratio of each component, etc., this EB and M100 can be made within the above-described range.

[0029] Furthermore, since the durability of the container provided in the tire of the present invention is more likely to be improved, it is more preferable that this EB and M100 satisfy the relationship of the following formula (1). In order to easily satisfy this relationship, within the range of the above-described configuration, for example, increasing the content ratio of natural rubber (NR) contained in the rubber component constituting the container, further reducing the carbon black content of the container, further reducing the average value of the nitrogen adsorption specific surface area (N 2 SA) of the carbon black contained in the container, etc. are preferably performed. (1) 1000 ≧ 275 × M100 - EB

[0030] And since the durability of the container provided in the tire of the present invention is more likely to be further improved, the value of 275 × M100 - EB is more preferably 950 or less, further preferably 800 or less, and further preferably 700 or less. The lower limit may be 100 or more, may be 200 or more, or may be 250 or more.

[0031] [Functional parts] As functional components to be accommodated in the container provided in the tire of the present invention, there are no limitations as long as they have a sensor function for detecting tire information and have a contact surface that comes into contact with the inner surface of the tread portion of the tire when accommodated in the container. For example, electronic components including various sensors, transmitters, receivers, control circuits, batteries, etc. are exemplified. Examples of tire information detected and acquired by the sensor function include the internal temperature and internal pressure (air pressure) of a pneumatic tire, the wear amount of the tread portion, etc. A temperature sensor or a pressure sensor can be used for measuring the internal temperature and internal pressure. For detecting the wear amount of the tread portion, a sensor element using a piezoelectric element is disposed on the contact surface, and a functional component that detects the output voltage corresponding to the tire deformation during running by the sensor element and detects the wear amount of the tread portion based on the output voltage is exemplified as a preferable one. That is, when the sensor function of this functional component is a sensor function using a piezoelectric element as a sensor element, it is more preferable from the viewpoint of detecting the wear amount of the tread portion. In addition, it is also possible to use an acceleration sensor or a magnetic sensor.

[0032] [Tire] The tire of the present invention has, for example, a tread portion 1 that extends in the tire circumferential direction and forms an annular shape, as shown in FIG. 1, and a pair of sidewall portions 2, 2 disposed on both sides (both ends in the tire width direction) of the tread portion 1, and a pair of bead portions 3, 3 disposed on the inner side in the tire radial direction of the pair of sidewall portions 2. An embodiment is shown.

[0033] And in this embodiment, at least one carcass layer 4 is mounted between the pair of bead portions 3, 3. This carcass layer 4 includes a plurality of reinforcing cords extending in the tire radial direction, and is folded back from the inner side to the outer side of the tire around the bead core 5 disposed in each bead portion 3. A bead filler 6 made of a rubber composition having a triangular cross section is disposed on the outer circumference of the bead core 5.

[0034] On one side, one or more (preferably multiple) belt layers 7 are arranged on the outer peripheral side of the carcass layer 4 in the tread portion 1. These belt layers 7 include a plurality of reinforcing cords inclined in substantially the same direction with respect to the tire circumferential direction (the reinforcing cords are embedded), and when including a plurality (for example, two layers) of belt layers 7, the reinforcing cords are arranged so as to cross each other between these layers. In the belt layer 7, the inclination angle of the reinforcing cord with respect to the tire circumferential direction is set, for example, in the range of 10° to 60° at the smaller angle. As the reinforcing cord of the belt layer 7, a steel cord is preferably used. On the outer peripheral side of the belt layer 7, for the purpose of improving high-speed durability, at least one belt cover layer 8 formed by arranging reinforcing cords at an angle of, for example, 5° or less with respect to the tire circumferential direction may be arranged. As the reinforcing cord of the belt cover layer 8, organic fiber cords such as nylon and aramid are preferably used.

[0035] Furthermore, a tread rubber layer 15 is arranged in the tread portion 1. The tread rubber layer 15 includes at least a cap tread rubber layer 15A. In this embodiment, it is composed of two layers, namely, the cap tread rubber layer 15A forming the tread surface of the tread portion 1 and the under tread rubber layer 15B located inside the cap tread rubber layer 15A in the tire radial direction. Note that the tread rubber layer 15 may include an earth tread made of conductive rubber exposed on the tire contact surface and wing tips respectively arranged at both ends in the tire width direction of the cap tread rubber layer 15A.

[0036] The constituent components of the tire of the present invention (components constituting each member such as the tread portion and each layer such as the belt layer) are not particularly limited, and known components for constituting a tire such as rubber components can be arbitrarily used. Also, the tire size and the use of the tire are not particularly limited, and it is possible to use various tires such as passenger car tires, truck bus tires, and off-road tires.

[0037] The tire of the present invention is provided with a container having the above-described configuration on the inner surface of the tire tread portion of the tire in such an embodiment. The arrangement position of this container is not particularly limited as long as it is the inner surface of the tire tread portion, and it may be a position that does not pass through the center point in the tire width direction on the inner surface of the tire tread portion.

[0038] In addition, the tire of the present invention is preferably a pneumatic tire. As the gas filled in this pneumatic tire, for example, air, nitrogen, argon, an inert gas such as helium, and other gases can be used.

[0039] The tire of the present invention (tire with a container) having the above-described configuration has excellent durability of the container that can accommodate functional components having a sensor function for detecting tire information provided on the inner surface of the tire tread portion. That is, even if repeated deformation or the like occurs in this container due to rotation, deformation of the tread portion, impact, etc. during tire running, breakage (such as cracking or separation of members) of this container is less likely to occur.

[0040] Hereinafter, examples of the present invention will be described. However, the present invention is not limited to the following examples, and various modifications are possible within the technical idea of the present invention.

Example

[0041] (Production and evaluation of tires with containers) Containers having the compositions shown in Table 1 or Table 2 below and the shapes shown in FIGS. 2 to 3 were produced, and these containers were bonded and fixed to the inner surface of the tire tread portion of a tire of tire size 225 / 50R16 92V with an adhesive as shown in FIG. 1 to produce various tires with containers.

[0042] Then, for the tires with containers of Reference Examples 1 to 2, Examples 1 to 6, and Comparative Examples 1 to 2 obtained, the tensile stress at 100% elongation (M100) at 100 ° C. and the elongation at break (EB) at 20 ° C. of the container were measured as follows, and an indoor durability test was also conducted.

[0043] <Tensile stress at 100% elongation at 100 °C (M100)> A dumbbell-shaped No. 7 rubber test piece (thickness 1.0 ± 0.1 mm) was taken from the accommodating portion in the accommodating body of each tire with an accommodating body obtained, and for this rubber test piece, a tensile test was carried out at a tensile speed of 500 mm / min in accordance with JIS K6251:2017, and the tensile stress at 100% elongation (MPa: M100) was measured at 100 °C. This result was shown in the middle rows of Table 1 and Table 2 below.

[0044] <Elongation at break at 20 °C (EB)> A dumbbell-shaped No. 7 rubber test piece (thickness 1.0 ± 0.1 mm) was taken from the accommodating portion in the accommodating body of each tire with an accommodating body obtained, and for this rubber test piece, a tensile test was carried out at a tensile speed of 500 mm / min in accordance with JIS K6251:2017, and the elongation at break (elongation rate at the time of cutting (%): EB) was measured at 20 °C. This result was shown in the middle rows of Table 1 and Table 2 below.

[0045] <Indoor durability test> For each tire equipped with a functional component using a piezoelectric element as a sensor element and mounted on the accommodating body such that the piezoelectric element was arranged on the contact surface contacting the inner surface of the tire, as a pretreatment, oxygen was enclosed at 350 kPa and stored at 80 °C for 5 days, assembled on a wheel, and an indoor running test was carried out using a drum tester under the running condition of increasing by 10 km / h every 2 hours from 81 km / h. Then, the speed at which the accommodating body was destroyed was taken as the test result. In addition, the destruction of this accommodating body was defined as a state in which the sensor function of the functional component could not be exerted due to cracks or detachment of the accommodating portion of the accommodating body. This result was shown in the lower rows of Table 1 and Table 2 below. The results were also expressed as an index with the value of Reference Example 1 as 100 for Examples 1 to 3 and Comparative Examples 1 to 2 (Table 1), and as an index with the value of Reference Example 2 as 100 for Examples 4 to 6 (Table 2).

[0046]

Table 1

[0047]

Table 2

[0048] The detailed contents of each component and the like in the above Tables 1 to 2 are as follows. · NR: Natural rubber (STR20, manufactured by Bonbndit Co., Ltd.) · BR: Butadiene rubber (Nipol BR1220, manufactured by Zeon Corporation, Japan) · CB1: Carbon black (Show black N330, nitrogen adsorption specific surface area (N 2 SA): 71 m 2 / g, manufactured by Cabot Japan Ltd.) · CB2: Carbon black (Show black N660, nitrogen adsorption specific surface area (N 2 SA): 34 m 2 / g, manufactured by Cabot Japan Ltd.) · Oil: Aroma oil (Diana Process NH-70S, manufactured by Idemitsu Kosan Co., Ltd.) · Zinc oxide: Zinc oxide (Silver Ridge R, manufactured by Toho Zinc Co., Ltd.) · Stearic acid: Bead stearic acid tung (manufactured by Chiba Fatty Acids Co., Ltd.) · Antioxidant: 6PPD (manufactured by Flexsys Co., Ltd.) · Sulfur: Sulfax 5 (manufactured by Tsurumi Chemical Industry Co., Ltd.) · Vulcanization accelerator: Nocceler DM-PO (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)

[0049] From these results, in Examples 1 to 6 where the container was composed of a rubber component containing 40% by mass or more of NR, and further contained 50 to 80 parts by mass of carbon black with respect to 100 parts by mass of this rubber component, and the EB at 20°C of the container was 160% or more and the M100 at 100°C was 4.9 MPa or less, the durability of the container was excellent. On the other hand, in Comparative Example 1 where the carbon black content of the container was high, and in Comparative Example 2 where the proportion of NR in the rubber component was low, the durability of the container was not improved in either case.

Explanation of symbols

[0050] 100 tires 1 tread portion 2 sidewall portions 3 bead portions 4 carcass layer 5 bead core 6 bead filler 7 belt layer 8 belt cover layer 11 tire circumferential grooves 12 inner surface of the tread portion of the tire 20 functional components 21 contact surface (piezoelectric element) 30 container 31 base 32 sidewall 33 accommodating portion

Claims

1. A tire is provided with a container capable of accommodating a functional component having a sensor function for detecting tire information on the inner surface of the tread portion so as to have a contact surface that contacts the inner surface of the tire. The container is made of a rubber component containing 35% by mass or more of natural rubber (NR), and further contains 10 to 85 parts by mass of carbon black with respect to 100 parts by mass of the rubber component. The tire has an elongation at break (EB) at 20°C of the container of 150% or more and a tensile stress at 100% elongation (M100) at 100°C of 5.0 MPa or less.

2. The tire according to claim 1, wherein the EB and the M100 of the container satisfy the relationship of the following formula (1). (1) 1000 ≧ 275 × M100 - EB

3. The average value of the nitrogen adsorption specific surface area (N 2 SA) of the carbon black is 60 m 2 / g or less. The tire according to claim 1 or 2.

4. The tire according to claim 1 or 2, wherein the content of the vulcanizing agent with respect to 100 parts by mass of the rubber component of the container is 3.5 parts by mass or less.

5. The tire according to claim 1 or 2, wherein the M100 is 1.3 MPa or more.

6. The tire according to claim 1 or 2, wherein the container is fixed to the inner surface of the tire, and the functional component is accommodated in the container so as to have a contact surface that contacts the inner surface of the tire.

7. The tire according to claim 6, wherein the container is fixed to the inner surface of the tire by an adhesive.

8. The tire according to claim 1 or 2, wherein the sensor function of the functional component is a sensor function using a piezoelectric element as a sensor element.

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