Tire with functional component

Abstract

[Problem] To provide a tire that has, on a tire-inner-surface of a tread section, a storage body storing a functional component, and that affords excellent sensing strength of a sensor function of the functional component and superior durability of the storage body. [Solution] The present invention solves the above problem by providing, on a tire-inner-surface of a tread section, a storage body storing a functional component. The functional component has at least a contact surface that contacts the tire-inner-surface and a sensor function for detecting tire information. The storage body comprises a rubber component, the rubber component containing 60 mass percent or more of butyl rubber (IIR) and a natural rubber (NR) content ratio of 40 mass percent or less, and further containing 40 to 82 parts by mass of carbon black with respect to 100 parts by mass of the rubber component.

Description

Tires with functional parts

[0001] The present invention relates to a tire having, on its inner surface, a functional component having a sensor function for detecting tire information.

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

[0003] International Publication No. WO 2022 / 123854 International Publication No. WO 2022 / 181267

[0004] Here, the housing that houses the functional components arranged on the inner surface of the tire tread portion is susceptible to forces due to tire rotation and impacts from the road surface during driving, posing a durability issue. Patent Documents 1 and 2 disclose tires that are less likely to peel off electronic component mounting members (housings) from the tire surface even when subjected to large impacts during high-speed driving or high-speed driving in low-temperature environments. However, these tires have room for improvement due to limitations on the rubber properties of the components that make up the tire and the mounting position of the electronic component mounting members (housings). Furthermore, the sensing strength of the sensor function of these functional components is difficult to increase due to the influence of tire rotation and other factors during driving, and this also leaves room for further improvement.

[0005] Therefore, an object of the present invention is to provide a tire that has a container containing functional parts on the inner surface of the tire in the tread portion, and that has excellent sensing strength of the sensor function of the functional parts and durability of the container.

[0006] In order to solve the above problems, the present inventors conducted extensive research and found that a tire comprising a housing containing a functional component on the inner surface of the tire tread portion, the functional component having at least a contact surface that comes into contact with the inner surface of the tire and a sensor function that detects tire information, the housing being made of a rubber component that contains 60% by mass or more of butyl rubber (IIR) and 40% by mass or less of natural rubber (NR), and further containing 40 to 82 parts by mass of carbon black per 100 parts by mass of the rubber component, has excellent sensing strength of the sensor function of the functional component and excellent durability of the housing, and completed the present invention.

[0007] That is, the present invention includes the following embodiments <1> to <11>. <1> A tire including a housing that houses a functional component on the tire inner surface of a tread portion, the functional component having at least a sensor function for detecting a contact surface that contacts the tire inner surface and tire information, the housing being made of a rubber component, the rubber component containing 60% by mass or more, more preferably more than 60% by mass, even more preferably 65% ​​by mass or more, and still more preferably 70% by mass or more of butyl rubber (IIR), and a natural rubber (NR) content of 40% by mass or less, more preferably less than 40% by mass, even more preferably 35% by mass or less, and still more preferably 30% by mass or less, and further containing 40 to 82 parts by mass, more preferably 45 to 80 parts by mass of carbon black per 100 parts by mass of the rubber component. <2> The tire according to <1>, wherein the housing contains 40 to 85 parts by mass, more preferably 45 to 80 parts by mass, of the carbon black and the white filler in total per 100 parts by mass of the rubber component. <3> The tire according to <2>, wherein the white filler is one or more (at least one) selected from the group consisting of silica, talc, mica, clay, and calcium carbonate. <4> The tire according to <2> or <3>, wherein the white filler is contained in an amount of 3 to 40 parts by mass, more preferably 10 to 30 parts by mass, per 100 parts by mass of the rubber component. <5> The tire according to any one of <1> to <4>, wherein the rubber component contains both butyl rubber and natural rubber, and the ratio of the butyl rubber to the natural rubber in the rubber component is 1.5 times or more (IIR / NR is 1.5 or more), more preferably 2 times or more. <6> The carbon black has an average nitrogen adsorption specific surface area (N2SA) of 50 m 2 / g or less, more preferably 10m 2 / g or more 45m 2 / g or less. <7> The tire according to any one of <1> to <6>, wherein the tensile stress at 100% elongation (M100) of the accommodating body at 100°C is 5.0 MPa or less, more preferably 1.0 MPa or more and 4.5 MPa or less, even more preferably 1.0 MPa or more and 4.0 MPa or less, even more preferably 1.0 MPa or more and 3.5 MPa or less, and even more preferably 1.0 MPa or more and 3.0 MPa or less. <8> The tire according to any one of <1> to <7>, wherein the accommodating body is fixed to the tire inner surface. <9> The tire according to <8>, wherein the accommodating body is fixed to the tire inner surface with an adhesive. <10> The tire according to any one of <1> to <9>, wherein the sensor function of the functional part is a sensor function using a piezoelectric element as a sensor element. <11> The tire according to <10>, wherein the piezoelectric element is arranged on the contact surface of the functional part that contacts the tire inner surface.

[0008] According to the present invention, a tire can be obtained that has a container containing functional parts on the inner surface of the tire in the tread portion, and that has excellent sensing strength of the sensor function of the functional parts and durability of the container.

[0009] The present invention relates to a tire and a tire tread portion, and ...

[0010] The present invention will be described. The present invention relates to a tire comprising a housing containing a functional component on the inner surface of the tire tread portion, the functional component having at least a contact surface that contacts the inner surface of the tire and a sensor function for detecting tire information, the housing being made of a rubber component, the rubber component containing 60% by mass or more of butyl rubber (IIR) and 40% by mass or less of natural rubber (NR), and further containing 40 to 82 parts by mass of carbon black per 100 parts by mass of the rubber component. Hereinafter, this will also be referred to as the "tire of the present invention."

[0011] In the present invention, unless otherwise specified, a numerical range expressed using "to" means a numerical range in which the numerical value written before "to" is the lower limit and the numerical value written after "to" is the upper limit.

[0012] The following describes in detail the configuration of the tire containing body, the components and their contents, and the overall configuration of the tire of the present invention, with reference to the drawings. Note that the dimensional ratios (length, thickness, etc.) and orientations of the components shown in the drawings may differ from the actual dimensional ratios and orientations in order to facilitate understanding of the invention. Also, some reference numerals may be omitted.

[0013] [Receptacle] The receptacle provided in the tire of the present invention is made of a predetermined rubber component. The receptacle is provided on the inner surface of the tire tread and contains a functional component having a sensor function for detecting tire information, with a contact surface that contacts the inner surface of the tire. For example, as shown in Figures 1 to 3, a base 31 of a receptacle 30 is joined and fixed to the inner surface 12 of the tire tread 1 (the tire inner surface 12 joined to the base 31 is omitted in Figures 2 and 3), and the receptacle 33 contains the functional component 20 surrounded by a sidewall 32, and the housed functional component 20 has a contact surface 21 that contacts the inner surface 12 of the tire tread 1 via the base 31.

[0014] Here, the phrase "provided on the tire inner surface of the tread" means that the container is connected to and disposed on the tire inner surface of the tread (the surface on the inner circumferential side of the tire that faces the tread surface of the tread). Furthermore, the phrase "having a contact surface that contacts the tire inner surface (of the tread)" includes not only embodiments in which the functional component has a contact surface that is in direct contact with the tire inner surface of the tread, but also embodiments in which the functional component has a contact surface that is in contact with the tire inner surface of the tread via a member of the container that is in surface contact with the tire inner surface of the tread (base 31 in the embodiment of FIG. 1). In other words, it includes embodiments in which the functional component is in direct surface contact with the tire inner surface of the tread, as well as embodiments in which the functional component is in surface contact with the tire inner surface of the tread via a member of the container that is in surface contact with the tire inner surface of the tread.

[0015] It is more preferable that the housing containing this functional component is fixed to the tire inner surface of the tread portion (so that the position of the housing does not change substantially), and more preferable that the housing is fixed to the tire inner surface of the tread portion with an adhesive. Epoxy adhesives, acrylic adhesives, etc. may be used as this adhesive. Double-sided tape, etc. may also be used as the adhesive.

[0016] The details of each component contained in this container and the physical properties of this container will be described below.

[0017] <Rubber Component> The container provided in the tire of the present invention is composed of a rubber component containing 60% by mass or more of butyl rubber (IIR) and 40% by mass or less of natural rubber (NR). In other words, this container is composed of a rubber component, and this rubber component contains 60% by mass or more of butyl rubber (IIR) and 40% by mass or less of natural rubber (NR). This rubber component is not particularly limited as long as it contains 60% by mass or more of butyl rubber (IIR) and 40% by mass or less of natural rubber (NR), and any known rubber component used in applications such as constructing rubber products, such as diene rubber or so-called non-diene rubber, can be used (in combination). Examples of diene rubbers include, in addition to the natural rubber (NR) described above, 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, and styrene-butadiene-vinylpyridine terpolymer (VP). Furthermore, in addition to the butyl rubber (IIR) described above, it is also possible to use rubber components other than diene rubbers, such as olefin rubber (ethylene propylene rubber, acrylic rubber, etc.), fluororubber, and silicone rubber. Furthermore, reclaimed butyl rubber obtained by recycling used rubber products and the like can also be used as the butyl rubber (IIR).

[0018] The content of butyl rubber (IIR) in the rubber component constituting the housing of the tire of the present invention is preferably more than 60% by mass, more preferably 65% ​​by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more. The upper limit may be 100% by mass, but is more preferably 95% by mass or less. The content of butyl rubber (IIR) in the present invention refers to the content of the entire butyl rubber, including recycled butyl rubber if it is included (the same applies hereinafter). The content of natural rubber (NR) in the rubber component constituting the housing of the tire of the present invention is more preferably less than 40% by mass, more preferably 35% by mass or less, even more preferably 30% by mass or less, and may be 20% by mass or less, or may be 10% by mass or less, since this makes it easier to achieve the effects of the present invention. The lower limit may be 0% by mass (an embodiment in which the content is substantially zero), but is more preferably 1% by mass or more, and even more preferably 5% by mass or more.

[0019] Furthermore, when the rubber component constituting the container contains both natural rubber (NR) and butyl rubber (IIR), the effects of the present invention are more easily achieved, and therefore the ratio of butyl rubber (IIR) to natural rubber (NR) in the rubber component is more preferably 1.5 times or more (IIR / NR is 1.5 or more), more preferably 2 times or more (IIR / NR is 2.0 or more), even more preferably 2.5 times or more (IIR / NR is 2.5 or more), even more preferably 3 times or more (IIR / NR is 3.0 or more), and even more preferably 5 times or more (IIR / NR is 5.0 or more). The upper limit is not particularly limited, but may be, for example, 50 times or less (IIR / NR is 50 or less).

[0020] <Carbon Black> The container provided in the tire of the present invention contains carbon black in addition to the above-mentioned predetermined rubber component, which is 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 that can be used include various grades such as SAF-HS, SAF, ISAF-HS, ISAF, ISAF-LS, IISAF-HS, HAF-HS, HAF, HAF-LS, FEF, GPF, SRF, FT, and MT. Recycled carbon black obtained by recycling used rubber products can also be used. This carbon black can be used alone or in combination of two or more types. It is to be noted that the average nitrogen adsorption specific surface area (N2SA) of this carbon black is preferably 50 m2 or more, since this facilitates further improving the durability of the container. 2 / g or less, and more preferably 45m 2 / g or less is more preferable, and 40m 2 / g or less is more preferable. In other words, the larger the particle size of the carbon black, the more preferable. The lower limit is 10 m 2 / g or more is more preferable, and 15m 2 / g or more, and more preferably 23m 2 It is more preferable that the SiO2 content is 1 / g or more.

[0021] Here, "carbon black" refers to fine carbon particles consisting of primary particles with a diameter of approximately 3 to 500 nm, which are manufactured under industrial quality control. The nitrogen adsorption specific surface area (N2SA) of carbon black is a value measured in accordance with JIS K6217-2:2017. Furthermore, the "average nitrogen adsorption specific surface area (N2SA) of carbon black" refers to the value of the nitrogen adsorption specific surface area (N2SA) of the carbon black when one type is used alone, and when two or more types are used in combination, refers to the value obtained by multiplying the nitrogen adsorption specific surface area (N2SA) of each carbon black used in combination by its respective usage ratio and adding the results together. In this calculation, the sum of the usage ratios of each carbon black is set to 1.0.

[0022] The container contains 40 to 82 parts by mass of the carbon black per 100 parts by mass of the rubber component constituting the container. The carbon black content is preferably 42 parts by mass or more, and more preferably 45 parts by mass or more, per 100 parts by mass of the rubber component. The upper limit is preferably 80 parts by mass or less, more preferably 75 parts by mass or less, even more preferably 70 parts by mass or less, even more preferably 65 parts by mass or less, even more preferably 60 parts by mass or less, and even more preferably 55 parts by mass or less, per 100 parts by mass of the rubber component. If the amount of carbon black is less than 40 parts by mass or more than 82 parts by mass per 100 parts by mass of the rubber component, the effects of the present invention may not be achieved. If the amount of carbon black is more than 82 parts by mass per 100 parts by mass of the rubber component, the insertability of the functional component into the container may be reduced. Here, the carbon black content in the present invention means the total content of all carbon blacks, including recycled carbon black, when multiple carbon blacks are included. The same applies hereinafter.

[0023] <White Filler> The housing provided in the tire of the present invention preferably further contains a white filler. The white filler is also not particularly limited, and any known white filler used in applications such as rubber products can be used. Specific examples of white fillers include silica, talc, mica, clay, and calcium carbonate. Examples of silica that can be used include wet silica, dry silica, fumed silica, and diatomaceous earth. Silica produced using biomass materials such as rice husks as raw materials may also be used. Heavy calcium carbonate is more preferable as calcium carbonate. One type of white filler may be used alone, or two or more types may be used in combination. Here, "silica" refers to a particulate material made of silicon dioxide (SiO2) or containing silicon dioxide as the main component (e.g., containing 80% by mass or more, or even 90% by mass or more).

[0024] When the container contains a white filler, the total content of the carbon black and the white filler is preferably 40 to 85 parts by mass per 100 parts by mass of the rubber component constituting the container. Furthermore, the total amount of the carbon black and the white filler is more preferably more than 40 parts by mass, even more preferably 45 parts by mass or more, and even more preferably 55 parts by mass or more per 100 parts by mass of the rubber component. The upper limit is more preferably 80 parts by mass or less, even more preferably 75 parts by mass or less, and even more preferably 70 parts by mass or less per 100 parts by mass of the rubber component. If the total amount of the carbon black and the white filler is less than 40 parts by mass or more than 85 parts by mass per 100 parts by mass of the rubber component, the effects of the present invention may not be achieved. Furthermore, if the total amount of the carbon black and the white filler is more than 85 parts by mass per 100 parts by mass of the rubber component, the insertability of the functional component into the container may be reduced. The content of the white filler (content of the white filler itself) is not limited, but is preferably 3 to 40 parts by mass per 100 parts by mass of the rubber component constituting the housing. The lower limit is more preferably 10 parts by mass or more per 100 parts by mass of the rubber component, and the upper limit is more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less per 100 parts by mass of the rubber component. However, the housing provided in the tire of the present invention may be configured to be substantially free of white filler.

[0025] <Other Components> The tire of the present invention may further contain optional components other than the rubber component, carbon black, and white filler described above, as long as the components do not significantly affect the effects of the present invention. For example, various additives commonly used in rubber products, such as resin components (terpene resin, coumarone resin, indene resin, rosin resin, etc.), zinc oxide (zinc white), oil (aromatic oil, etc.), stearic acid, wax, lecithin, antioxidants, plasticizers, vulcanizing agents, vulcanization accelerators, and vulcanization accelerator aids, may be contained in appropriate amounts. Sulfur is a typical example of a vulcanizing agent, but components other than sulfur may also include compounds such as peroxides that have a crosslinking function between polymers. These may also be used in combination.

[0026] For example, the contents of the oil, stearic acid, zinc oxide, and resin component in the container are each preferably 0.5 to 10 parts by mass, and more preferably 1.0 to 8.0 parts by mass, per 100 parts by mass of the rubber component constituting the container. The content of sulfur in the container is preferably 0.5 to 5.0 parts by mass, per 100 parts by mass of the rubber component constituting the container. Furthermore, the content of the vulcanization accelerator in the container, either as a primary accelerator alone or as a blend with a secondary accelerator, is preferably 0.3 to 3.0 parts by mass, and more preferably 0.5 to 2.0 parts by mass, per 100 parts by mass of the rubber component constituting the container.

[0027] Furthermore, when silica is used as a white filler, the tire housing of the present invention may further contain a silane coupling agent to further enhance the dispersibility of the silica. The silane coupling agent is not particularly limited as long as it is a silane compound having a hydrolyzable group and an organic functional group. The hydrolyzable group is also not limited, but examples include an alkoxy group, a phenoxy group, a carboxy group, and an alkenyloxy group. An alkoxysilyl group in which the alkoxy group is bonded to a silicon atom is preferred. When the hydrolyzable group is an alkoxysilyl group, the alkoxy group preferably has 1 to 16 carbon atoms, and more preferably has 1 to 4 carbon atoms. Examples of alkoxy groups having 1 to 4 carbon atoms include a methoxy group, an ethoxy group, and a propoxy group.

[0028] The organic functional group is not limited, but may be any group capable of forming a chemical bond with an organic compound, such as an epoxy group, a vinyl group, an acryloyl group, a methacryl group, an amino group, a sulfide group (particularly, a polysulfide group (-S n Examples of the silane coupling agent include a sulfide group (particularly a disulfide group or a tetrasulfide group), a mercapto group, and a blocked mercapto group (protected mercapto group) (e.g., an octanoylthio group), and among these, a sulfide group (particularly a disulfide group or a tetrasulfide group), a mercapto group, and a blocked mercapto group are preferred. One of these silane coupling agents may be used alone, or two or more may be used in combination. The silane coupling agent is preferably a sulfur-containing silane coupling agent.

[0029] When silica is used as the white filler, the silane coupling agent is preferably contained in an amount of 1 to 20 parts by mass, more preferably 2 to 10 parts by mass, per 100 parts by mass of the silica.

[0030] <Tensile Stress at 100% Elongation at 100°C (M100)> The container provided in the tire of the present invention has the configuration described above, and more preferably, the tensile stress at 100% elongation at 100°C (M100) of this container is 5.0 MPa or less. This is because the container and the like are likely to have sufficient durability to withstand forces and impacts caused by rotation while the tire is running. This M100 is more preferably 4.5 MPa or less, even more preferably 4.0 MPa or less, even more preferably 3.5 MPa or less, and even more preferably 3.0 MPa or less. The lower limit is more preferably 0.8 MPa or more, even more preferably 1.0 MPa or more, and even more preferably 1.3 MPa or more, because this makes it easier to prevent functional components from falling off.

[0031] Here, this M100 is a value confirmed by a method in which a predetermined rubber test piece (for example, a dumbbell-shaped No. 7) is taken from the container, a tensile test is performed on this rubber test piece at a tensile speed of 500 mm / min in accordance with JIS K6251:2017, and the tensile stress at 100% elongation (MPa: M100) is measured at 100° C. Then, by adjusting the ratio of each component in the above-mentioned configuration, this M100 can be set within the above-mentioned range.

[0032] [Functional Components] The functional components housed in the tire housing of the present invention are not limited as long as they have a sensor function for detecting tire information and a shape that allows them to have a contact surface that contacts the tire inner surface of the tread. Examples include electronic components including various sensors, transmitters, receivers, control circuits, batteries, etc. Tire information detected and acquired by the sensor function includes the internal temperature and internal pressure (air pressure) of the pneumatic tire, and the amount of wear in the tread. Temperature sensors and pressure sensors can be used to measure the internal temperature and internal pressure. A preferred example of a functional component for detecting the amount of wear in the tread is one in which a sensor element using a piezoelectric element is disposed on the contact surface, and the sensor element detects an output voltage corresponding to tire deformation during driving, and the amount of wear in the tread is detected based on the output voltage. In other words, a sensor function using a piezoelectric element as the sensor element is more preferable from the perspective of detecting the amount of wear in the tread. Alternatively, an acceleration sensor or a magnetic sensor can also be used.

[0033] [Tire] As shown in FIG. 1 , the tire of the present invention has an embodiment including a tread portion 1 extending in the tire circumferential direction to form an annular shape, a pair of sidewall portions 2, 2 arranged on both sides of the tread portion 1 (both ends in the tire width direction), and a pair of bead portions 3, 3 arranged radially inward of the pair of sidewall portions 2.

[0034] 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 inside to the outside of the tire around a bead core 5 disposed in each bead portion 3. A bead filler 6 made of a rubber composition and having a triangular cross section is disposed on the outer periphery of the bead core 5.

[0035] Meanwhile, one or more belt layers 7 (preferably multiple layers) are disposed on the outer peripheral side of the carcass layer 4 in the tread portion 1. These belt layers 7 include multiple reinforcing cords inclined in approximately the same direction with respect to the tire circumferential direction (the reinforcing cords are embedded), and when multiple belt layers 7 (e.g., two layers) are included, the reinforcing cords are disposed so as to cross each other between these layers. In the belt layers 7, the inclination angle of the reinforcing cords with respect to the tire circumferential direction is set, for example, in the range of 10° to 60° as the smaller angle. Steel cords are preferably used as the reinforcing cords of the belt layers 7. At least one belt cover layer 8 may be disposed on the outer peripheral side of the belt layers 7, with the reinforcing cords arranged at an angle of, for example, 5° or less with respect to the tire circumferential direction, for the purpose of improving high-speed durability. Organic fiber cords such as nylon and aramid cords are preferably used as the reinforcing cords of the belt cover layer 8.

[0036] Furthermore, a tread rubber layer 15 is disposed in the tread portion 1. The tread rubber layer 15 includes at least a cap tread rubber layer 15A. In this embodiment, the tread rubber layer 15 is configured of two layers: the cap tread rubber layer 15A that forms the tread surface of the tread portion 1, and an under tread rubber layer 15B that is positioned radially inward of the cap tread rubber layer 15A. The tread rubber layer 15 may also include an earth tread made of conductive rubber that is exposed on the tire contact surface, and wing tips that are disposed on both ends of the cap tread rubber layer 15A in the tire width direction.

[0037] The components constituting 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 any known components for constituting tires, such as rubber components, can be used. In addition, the tire size and the tire application are not particularly limited, and various types of tires, such as passenger car tires, truck and bus tires, and off-road tires, can be used.

[0038] The tire of the present invention is provided with a container having the above-described configuration on the inner surface of the tread portion of the tire according to this embodiment. The location of this container is not particularly limited as long as it is on the inner surface of the tread portion, and it may be a location that does not pass through the center point of the inner surface of the tread portion in the tire width direction.

[0039] The tire of the present invention is preferably a pneumatic tire. The gas to be filled into the pneumatic tire may be, for example, air, an inert gas such as nitrogen, argon, or helium, or other gases.

[0040] The tire (tire with functional components) of the present invention configured as described above has excellent sensing strength of the sensor function of the functional components provided on the inner surface of the tire tread, and further has excellent durability of the housing that houses the functional components. In other words, even if the housing is repeatedly deformed due to rotation of the tire while it is running, deformation of the tread, impact, etc., the housing is less likely to be damaged (cracked, components separated, etc.).

[0041] Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples, and various modifications are possible within the technical concept of the present invention.

[0042] (Preparation and Evaluation of Tires with Functional Parts) Each of the containers was prepared having the composition shown in Table 1 below and having the shapes shown in Figures 2 and 3. Each of these containers was bonded and fixed to the inner surface of the tire tread portion of a tire having a tire size of 235 / 55R17 96V with an adhesive as shown in Figure 1. Furthermore, a functional part using a piezoelectric element as a sensor element was attached to the container so that the piezoelectric element was positioned on the contact surface that would come into contact with the inner surface of the tire, thereby preparing tires with various functional parts.

[0043] Then, for the tires with functional parts obtained in Reference Example 1, Comparative Examples 1 to 6, and Examples 1 to 5, the rubber hardness (HS) of the housing body and the tensile stress at 100% elongation (M100) were measured, and the sensing strength, detachability (difficulty in detaching), insertability, and durability of the housing body were evaluated as follows.

[0044] <Rubber Hardness (HS)> A dumbbell-shaped No. 7 rubber test piece (thickness 1.0±0.1 mm) was collected from the housing portion of the housing body of each of the obtained tires with functional components, and the rubber hardness (HS) of this rubber test piece was measured at a temperature of 20° C. using a durometer Type A (manufactured by Toyo Seiki Seisaku-Sho, Ltd.) in accordance with JIS K6253-3:2012. The results are shown in the middle section of Table 1 below.

[0045] <Tensile stress at 100% elongation (M100)> A dumbbell-shaped No. 7 rubber test piece (thickness 1.0±0.1 mm) was collected from the housing portion of the housing body of each of the obtained tires with functional components, and a tensile test was performed on this rubber test piece at a pulling rate of 500 mm / min in accordance with JIS K6251:2017 to measure the tensile stress at 100% elongation (MPa: M100) at 20° C. and 100° C. These results are shown in the middle section of Table 1 below.

[0046] <Sensing strength> Each tire with functional parts obtained was mounted on a wheel, air-pressurized to 230 kPa, and run on a drum test machine at a speed of 30 km / h. The peak height of the waveform detected by the sensor element of the functional part was measured. The results are shown in the lower part of Table 1 below. The results are expressed as an index, with the value of Reference Example 1 set to 100.

[0047] <Functional Component Detachability> Each tire with functional components obtained was mounted on a wheel, inflated to an air pressure of 360 kPa, and run on a drum tester. The tire was accelerated to a speed of 260 km / h over the first 10 minutes, and then accelerated by 10 km / h every 10 minutes. The speed at which the functional component fell off the housing was recorded as the test result. The results are shown in the lower part of Table 1 below. The results are expressed as an index, with the value of Reference Example 1 set to 100.

[0048] <Insertion Efficiency> Whether or not the same functional part could be inserted in one go into each housing joined and fixed to the inner surface of the tire was evaluated with a circle or an X. The results are shown in the lower part of Table 1 below.

[0049] <Durability of the Housing> Each tire with functional parts obtained was pretreated by sealing it in oxygen at 350 kPa and storing it at 80°C for 5 days. It was then mounted on a wheel and subjected to an indoor running test using a drum tester, in which the running conditions were increased by 10 km / h every 2 hours from 81 km / h to 150 km / h. A rating of × was given to cases in which the housing was broken, and a rating of ◯ was given to cases in which no damage was caused. The housing was broken when the sensor function of the functional part could no longer be performed due to cracking or detachment of the housing portion of the housing. The results are shown in the lower part of Table 1 below.

[0050]

[0051] The details of each component in Table 1 are as follows: NR: Natural rubber (SIR20, manufactured by PT. PANTJA SURYA) IIR: Butyl rubber (EXXON Bromobutyl 2255, manufactured by ExxonMobil Chemical Company) CB1: Carbon black (GPF, nitrogen adsorption specific surface area (NSA): 35 m 2 / g, Nitelon #GN: manufactured by Shin-Nichika Carbon Co., Ltd.) CB2: carbon black (HAF, nitrogen adsorption specific surface area (NSA): 93 m 2 / g, Seest KH: manufactured by Tokai Carbon Co., Ltd.) Zinc oxide: Ginrei R (manufactured by Toho Zinc Co., Ltd.) Stearic acid: Beads Stearic Acid Kiri (manufactured by Chiba Fatty Acid Co., Ltd.) Resin (resin component): C5 resin (Homogenizing Agent H40MSF, manufactured by SHANDONG YANGGU HUATAI CHEMICAL CO., LTD.) Aroma oil: Aroma oil (Diana Process NH-70S, manufactured by Idemitsu Kosan Co., Ltd.) Sulfur: Sulfax 5 (manufactured by Tsurumi Chemical Industry Co., Ltd.) Vulcanization accelerator: Noccela DM-PO (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Silica 1: Silica (ULTRASIL VN3GR, CTAB specific surface area 170 m 2 / g: manufactured by Evonik)

[0052] These results indicate that by incorporating a predetermined amount of carbon black into a housing made of a rubber component containing 65% or more IIR by mass and 35% or less NR by mass, the sensing strength, shedding resistance, and insertability of the functional part are improved, as well as the durability of the housing (Examples 1 to 5). On the other hand, when the proportion of butyl rubber or the content of carbon black in the rubber component was low, the sensing strength and shedding resistance of the functional part were reduced (Comparative Examples 1, 2, and 4), and when the content of carbon black was high, the insertability of the functional part and the durability of the housing were reduced (Comparative Examples 3 and 6). Furthermore, when silica was used as a substitute for carbon black, the insertability of the functional part was reduced (Comparative Example 5).

[0053] Furthermore, in the same manner as above, various containers having the compositions shown in Table 2 below and having shapes as shown in Figures 2 and 3 were prepared, and these containers were bonded and fixed to the inner surface of the tire tread portion of a tire having a tire size of 235 / 55R17 96V as shown in Figure 1, and the same functional part using a piezoelectric element as a sensor element was attached to the container to prepare tires with various functional parts.

[0054] The resulting tires with functional parts of Reference Example 2, Comparative Example 7, and Examples 9 to 18 were subjected to measurement of the tensile stress at 100% elongation (M100) of the housing body at 100°C and evaluation of the sensing strength of the functional parts using the same method as described above. Furthermore, the durability of the housing body was evaluated using the same indoor running test as described above, with the running conditions increasing by 10 km / h every two hours from 81 km / h, and the speed at which the housing body broke was recorded as the test result. The results are shown in the middle and bottom rows of Table 2 below. The results of the sensing strength of the functional part and the durability of the housing body are all expressed as an index, with the value of Reference Example 2 being 100.

[0055]

[0056] Regarding the details of each component in Table 2, components that overlap with those in Table 1 are the same as those in Table 1, and components not listed in Table 1 are as follows: CB3: Carbon black (FEF, nitrogen adsorption specific surface area (NSA): 42 m 2 / g, SEAT SO: manufactured by Tokai Carbon Co., Ltd.) Silica 2: silica (ULTRASIL 115GR, CTAB specific surface area 114 m 2 / g: manufactured by Evonik) Clay: T Clay (manufactured by Saitama Mineral Co., Ltd.) Calcium carbonate: heavy calcium carbonate (manufactured by Maruo Calcium Co., Ltd.) Talc: MH (manufactured by Nippon Talc Co., Ltd.) Silane coupling agent: Si69 (manufactured by Evonik Co., Ltd.)

[0057] These results indicate that similar effects can be achieved when a container made of a rubber component containing 70% or more IIR by mass and 30% or less NR is used with a predetermined amount of silica, clay, calcium carbonate, or talc as a white filler together with carbon black (Examples 9 to 18).On the other hand, when the carbon black content and the total amount of carbon black and silica were low, the sensing strength of the functional part decreased (Comparative Example 7).

[0058] This application claims priority based on Japanese Patent Application No. 2023-196858, filed November 20, 2023, the disclosure of which is incorporated herein in its entirety by reference.

[0059] REFERENCE SIGNS LIST 100 Tire 1 Tread portion 2 Sidewall portion 3 Bead portion 4 Carcass layer 5 Bead core 6 Bead filler 7 Belt layer 8 Belt cover layer 11 Tire circumferential groove 12 Tire inner surface of tread portion 20 Functional part 21 Contact surface (piezoelectric element) 30 Housing 31 Base portion 32 Sidewall 33 Housing portion

Claims

1. A tire comprising a housing in which a functional part is housed on the inner surface of the tire tread portion, said functional part having at least a contact surface that comes into contact with said inner surface of the tire and a sensor function for detecting tire information, said housing being made of a rubber component, said rubber component containing 60 mass% or more of butyl rubber (IIR) and 40 mass% or less of natural rubber (NR), and further containing 40 to 82 mass parts of carbon black per 100 mass parts of said rubber component.

2. The tire according to claim 1, wherein the container contains 40 to 85 parts by mass of the carbon black and the white filler in total per 100 parts by mass of the rubber component.

3. The tire according to claim 2, wherein the white filler is at least one selected from the group consisting of silica, talc, mica, clay, and calcium carbonate.

4. The average nitrogen adsorption specific surface area (N2SA) of the carbon black is 50 m 2 The tire according to any one of claims 1 to 3, wherein the linear modulus is 1 / g or less.

5. The tire according to any one of claims 1 to 3, wherein the tensile stress at 100% elongation (M100) of the container at 100°C is 5.0 MPa or less.

6. The tire according to any one of claims 1 to 3, wherein the container is fixed to the inner surface of the tire.

7. The tire of claim 6, wherein said containment body is secured to said inner tire surface by an adhesive.

8. The tire according to any one of claims 1 to 3, wherein the sensor function of the functional part is a sensor function using a piezoelectric element as a sensor element.

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