Tire and manufacturing method of the same

Abstract

To provide a tire which enables improvement of durability of a conductive member when the conductive member used for signal communication and power supply of an electronic device is installed on an inner surface rubber layer, and to provide a manufacturing method of the tire.SOLUTION: A tire includes: an inner surface rubber layer 10 forming a tire inner surface; and a conductive member 20 disposed on the inner surface rubber layer 10. The conductive member 20 is formed of a knitted fabric at least partially formed of a conductive yarn 23 and having elasticity. At least a part of a conductive part 21 formed of the conductive yarn 23 is filled with an elastomer 25 for filling spaces in the knitted fabric.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a tire having an inner surface rubber layer provided with a conductive member used for signal communication and power supply of electronic devices, and a manufacturing method thereof, and more particularly to a tire that makes it possible to improve the durability of the conductive member, and a manufacturing method thereof. [Background technology]

[0002] Conventionally, in a pneumatic tire, an electronic device is installed on the inner surface of the tire, and a conductive member is electrically connected to the electronic device, and communication and power supply are performed via the conductive member. As such a conductive member, a conductive wiring such as a metal wire is provided on the inner surface of the tire (for example, see Patent Documents 1 to 5).

[0003] However, tires deform during operation, and if excessive tension is applied to the wiring due to tire deformation, the wiring may break. Such a breakage can impair the functionality of the electronic device. Furthermore, repairing the wiring installed on the inner surface of the tire requires removing the tire from the rim. Therefore, the wiring of electronic devices must be highly durable.

[0004] In view of this situation, it has been proposed to reduce the tension applied to the conductive yarn by forming a conductive member from a knitted fabric containing conductive yarn and imparting stretchability to the conductive member (see, for example, Patent Document 6). However, even with this structure, the conductive yarn may break, and further improvement is required. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2007-537090 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-203829 [Patent Document 3] Japanese Patent Application Laid-Open No. 2017-217953 [Patent Document 4] Japanese Patent Application Laid-Open No. 2015-205528 [Patent Document 5] Japanese Patent Application Publication No. 2019-77296 [Patent Document 6] Patent No. 7173141 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a tire and a manufacturing method thereof that make it possible to improve the durability of a conductive member used in signal communication and power supply of electronic devices when the conductive member is installed on the inner surface rubber layer. [Means for solving the problem]

[0007] In order to achieve the above object, the tire of the present invention includes an inner surface rubber layer that forms an inner surface of the tire, and a conductive member disposed on the inner surface rubber layer, The conductive member is made of an elastic knitted fabric, at least a portion of which is made of conductive yarn, and at least a portion of the conductive portion made of the conductive yarn is filled with an elastomer that fills the spaces in the knitted fabric.

[0008] Further, a tire manufacturing method of the present invention is a method for manufacturing the above-mentioned tire, a step of molding an unvulcanized tire having the inner surface rubber layer; impregnating the conductive member with an elastomer and drying the elastomer; attaching the conductive member to the inner surface rubber layer; and vulcanizing the unvulcanized tire together with the conductive member. [Effects of the Invention]

[0009] In the present invention, the conductive member is a stretchable knitted fabric at least partially composed of conductive yarns. Therefore, even if the conductive member stretches with tire deformation, the tension applied to the conductive yarns constituting the knitted fabric is reduced, thereby preventing breakage of the conductive yarns. Furthermore, at least a portion of the conductive portion made of conductive yarns is filled with an elastomer that fills the spaces in the knitted fabric. This prevents direct contact between the conductive yarns when the knitted fabric stretches and contracts, thereby preventing fatigue breakage due to repeated contact and separation between the conductive yarns. This improves the durability of the conductive member.

[0010] In the present invention, the conductive thread is preferably a metal wire with an insulating coating. The insulating coating can prevent unintended short circuits in the electrical wiring formed by the conductive member. Furthermore, if the insulating coating melts when heat is applied, the conductive member can be electrically connected to an electronic device or the like by soldering.

[0011] In the present invention, it is preferable that the elastomer is exposed on at least one surface of the knitted fabric, and the conductive member is fixed to the inner surface rubber layer via the elastomer. By fixing the conductive member to the inner surface rubber layer via the elastomer, the conductive member can smoothly follow the movement of the inner surface rubber layer and transmit power while maintaining durability. Moreover, compared to when the knitted fabric is directly fixed to the inner surface rubber layer, stress applied to the knitted fabric can be alleviated, thereby improving the durability of the conductive member.

[0012] In the present invention, the elastomer preferably contains a diene rubber. Diene rubber has sufficient elongation, and therefore can effectively improve the durability of the conductive member. Furthermore, when the inner surface rubber layer of the tire contains butyl rubber, the use of a diene rubber as the elastomer that fills the spaces in the knitted fabric can improve the adhesion between the conductive member and the inner surface rubber layer.

[0013] In the present invention, it is preferable that at least a part of the conductive member is arranged in a flex zone defined between a perpendicular line extending from an end of a belt layer embedded in the tread portion to the tire inner surface and a perpendicular line extending from an outer diameter side end of a bead core embedded in the bead portion to the tire inner surface. In the present invention, the tension applied to the conductive yarn due to tire deformation can be alleviated, and therefore a significant effect can be exhibited when at least a part of the conductive member is arranged in a flex zone where deformation of the tire inner surface is relatively large.

[0014] When the conductive member is arranged across the flex zone, it is preferable that the conductive member have a terminal electrically connected to the conductive yarn outside the flex zone. Since the terminal electrically connected to the conductive yarn is more susceptible to breakage due to tire deformation than other parts, arranging the terminal outside the flex zone can increase the durability of the conductive member.

[0015] In the present invention, when the conductive member has a terminal electrically connected to the conductive thread, it is preferable that the region including the terminal is not filled with elastomer. If the region including the terminal is also filled with elastomer and the terminal is consequently covered with elastomer, it becomes difficult to solder a wiring member to the terminal, so it is preferable that the region including the terminal is not filled with elastomer.

[0016] In the present invention, when the conductive member has a terminal electrically connected to the conductive thread and a wiring member connected to the terminal, it is preferable that the region including the terminal is also filled with elastomer. When the conductive member has a terminal and a wiring member already connected to the terminal, even if the region including the terminal is filled with elastomer, there is no need to worry about poor soldering between the terminal and the wiring member.

[0017] Furthermore, according to the tire manufacturing method of the present invention, the tire can be manufactured efficiently and the durability of the conductive member can be improved by including the steps of: molding an unvulcanized tire having the inner surface rubber layer; impregnating the conductive member with an elastomer and drying the elastomer; attaching the conductive member to the inner surface rubber layer; and vulcanizing the unvulcanized tire together with the conductive member. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a meridian half cross-sectional view showing a pneumatic tire according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing an example of a conductive member used in the present invention. [Figure 3] 1 is a plan view showing a knitted fabric of a conductive member used in the present invention. FIG. [Figure 4] 1(a) and 1(b) are cross-sectional views showing modified examples of the conductive member used in the present invention. [Figure 5] FIG. 10 is a perspective view showing a modified example of the conductive member used in the present invention. [Figure 6] FIG. 10 is a perspective view showing a modified example of the conductive member used in the present invention. [Figure 7] 3A to 3C are explanatory views showing a manufacturing process of the conductive member used in the present invention. [Figure 8] 10A to 10C are explanatory views showing a modified example of the manufacturing process of the conductive member used in the present invention. [Figure 9] 10A to 10C are explanatory views showing a modified example of the manufacturing process of the conductive member used in the present invention. [Figure 10] 1 is a meridian half cross-sectional view showing an example of the arrangement of electronic devices in a pneumatic tire. [Figure 11] FIG. 1 is a perspective view showing a connection structure between an electronic device and a conductive member. [Figure 12] FIG. 10 is a perspective cross-sectional view showing another example of the arrangement of electronic devices in a pneumatic tire. [Figure 13] FIG. 10 is a perspective cross-sectional view showing another example of the arrangement of electronic devices in a pneumatic tire. [Figure 14] FIG. 10 is a perspective cross-sectional view showing another example of the arrangement of electronic devices in a pneumatic tire. DETAILED DESCRIPTION OF THE INVENTION

[0019] The configuration of the present invention will be described in detail below with reference to the accompanying drawings. Fig. 1 shows a pneumatic tire according to an embodiment of the present invention, and Figs. 2 and 3 show conductive members used in the present invention. In Fig. 1, CL is the tire center line.

[0020] 1, the pneumatic tire of this embodiment includes 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, and a pair of bead portions 3, 3 arranged radially inward of the sidewall portions 2. This pneumatic tire has a substantially symmetrical structure on both sides of the tire center line CL, but may also have an asymmetrical structure.

[0021] A carcass layer 4 is mounted between a pair of bead portions 3, 3. This carcass layer 4 includes a plurality of carcass 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. Organic fiber cords such as polyester fiber cords are preferably used as the carcass cords of the carcass layer 4. 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.

[0022] Meanwhile, multiple belt layers 7 are embedded on the outer peripheral side of the carcass layer 4 in the tread portion 1. These belt layers 7 include multiple belt cords that are inclined with respect to the tire circumferential direction, and are arranged so that the belt cords cross each other between the layers. In the belt layers 7, the inclination angle of the belt cords with respect to the tire circumferential direction is set to a range of 10° to 40°, for example. Steel cords are preferably used as the belt cords 7 of the belt layers 7. In the tread portion 1, multiple main grooves 11 extending in the tire circumferential direction and multiple lug grooves 12 extending in the tire width direction are formed. In the tread portion 1, grooves and sipes other than the main grooves 11 and lug grooves 12 can be provided as needed.

[0023] A belt cover layer 8 is arranged on the outer circumferential side of the belt layer 7, with the aim of improving high-speed durability, and is made up of reinforcing cords arranged at an angle of, for example, 5° or less with respect to the tire circumferential direction. The belt cover layer 8 may be a full cover layer that covers the entire width of the belt layer 7, or a pair of edge cover layers that locally cover both ends of the belt layer 7 in the tire width direction, either alone or in combination. The belt cover layer 8 may be formed, for example, by spirally winding a strip material in the tire circumferential direction, in which at least one reinforcing cord is aligned and covered with coating rubber.

[0024] The tire internal structure described above shows a typical example of a pneumatic tire, but is not limited to this. An inner surface rubber layer (inner liner layer) 10 that constitutes the tire inner surface S is disposed inside the carcass layer 4. The inner surface rubber layer 10 is an air permeation prevention layer and is made of a rubber composition mainly containing butyl rubber.

[0025] In the above-described pneumatic tire, as shown in FIG. 1, a strip-shaped conductive member 20 is disposed on the inner surface rubber layer 10 so as to extend in the tire radial direction. The conductive member 20 is electrically connected to an electronic device (not shown) and is used for signal communication and power supply for the electronic device. The electronic device is a device that operates using electrical energy, and may be composed of, for example, a power generation element, sensors that measure physical quantities such as pressure, temperature, acceleration, electric field, magnetic field, potential, electric resistance, and gas concentration, actuators such as motors and pumps, communication modules, wireless tags, receiving or transmitting antennas, secondary batteries, coils for contactless power supply, electronic circuit boards, etc.

[0026] As shown in FIGS. 2 and 3 , the conductive member 20 is made of a stretchable knitted fabric, at least a portion of which is made of conductive yarns 23. More specifically, the conductive member 20 is a knitted fabric formed by knitting conductive yarns 23 and non-conductive yarns 24. Conductive portions 21 made of the conductive yarns 23 and non-conductive portions 22 made of the non-conductive yarns 24 extend along the longitudinal direction of the conductive member 20, and these conductive portions 21 and non-conductive portions 22 are alternately arranged in the width direction of the conductive member 20. Since each conductive portion 23 includes conductive yarns 23 that are continuous along the longitudinal direction of the conductive member 20, each conductive portion 21 functions as a conductive path in the longitudinal direction of the conductive member 20. Furthermore, to ensure insulation between adjacent conductive portions 21, 21, it is preferable that the width of the non-conductive portions 22 located between adjacent conductive portions 21, 21 be 0.5 mm or more. The knitting method of the knitted fabric of the conductive member 20 is not particularly limited, as long as the conductive yarns 23 are continuous and the knitted fabric is stretchable. A knitted fabric is stretchable when its breaking elongation from a non-stretched state is 50% or more. The breaking elongation of the knitted fabric is preferably 100% or more. Furthermore, the conductive member 20 preferably has conductive yarns 23 exposed on both sides of the knitted fabric and has a uniform structure in the thickness direction.

[0027] As shown in Figure 3, at least a portion of the conductive portion 21 made of conductive yarn 23 is filled with elastomer 25 that fills the spaces in the knitted fabric. In Figure 3, the entire knitted fabric that constitutes the conductive member 20 is filled with elastomer 25. It is preferable that the breaking elongation of the elastomer 25 is greater than the breaking elongation of the knitted fabric that constitutes the conductive member 20. The breaking elongation of the elastomer 25 is preferably 400% or more. Preferred examples of the elastomer 25 include natural rubber, silicone rubber, and urethane elastomer. It is preferable that the volume ratio of the elastomer 25 to the entire volume of the conductive member 20 filled with elastomer 25 is 60% or more.

[0028] The conductive thread 23 is preferably a metal wire with an insulating coating, particularly a copper wire with an insulating coating. The insulating coating can prevent unintended short circuits in the electrical wiring formed by the conductive member 20. Furthermore, if the insulating coating melts when heat is applied, the conductive member 20 can be electrically connected to an electronic device by soldering. Resin materials such as polyurethane, polyester, polyvinyl formal, polyethylene, polyvinyl chloride, polyamide, polyamideimide, polyesterimide, and polyimide are preferred as insulating coatings.

[0029] The conductive yarn 23 may be formed from a single metal wire (monofilament), but is preferably formed from a bundle of multiple metal wires (multifilament). The diameter of the metal wire, including the insulating coating, is preferably in the range of 10 μm to 100 μm, more preferably 20 μm to 80 μm. A single conductive yarn 23 may be formed from a bundle of 3 to 12 metal wires. For example, a conductive yarn 23 formed from a bundle of seven metal wires with a diameter of 30 μm is exemplified. The non-conductive yarn 24 may be formed from a yarn made from synthetic fibers such as polyester fiber or aramid fiber. The non-conductive yarn 24 may be formed from a bundle of multiple fibers. In this case, it is preferable to use a yarn formed from a bundle of a larger number of fibers that are thinner than the metal wires of the conductive yarn 23. This ensures the flexibility of the knitted fabric even when the conductive yarn 23 is knitted.

[0030] In the tire described above, the conductive member 20 is a stretchable knitted fabric at least a portion of which is made of conductive yarns 23. This reduces the tension on the conductive yarns 23 that make up the knitted fabric even when the conductive member 23 stretches as the tire deforms, thereby preventing breakage of the conductive yarns 23. Furthermore, at least a portion of the conductive portion 21 made of the conductive yarns 23 is filled with an elastomer 25 that fills the spaces in the knitted fabric, preventing the conductive yarns 23 from coming into direct contact with each other when the knitted fabric stretches and contracts, thereby preventing fatigue breakage caused by repeated contact and separation between the conductive yarns 23. This improves the durability of the conductive member 20.

[0031] 4(a) and 4(b) show modified examples of the conductive member used in the present invention. In FIGS. 4(a) and 4(b), the elastomer 25 is exposed on at least one surface of the knitted fabric of the conductive member 20, and the conductive member 20 is fixed to the inner surface rubber layer 10 via the elastomer 25. The elastomer 25 may be exposed on both surfaces of the knitted fabric of the conductive member 20 as shown in FIG. 4(a), or may be exposed on only one surface of the knitted fabric of the conductive member 20 as shown in FIG. 4(b). Fixing the conductive member 20 to the inner surface rubber layer 10 via the elastomer 25 allows the conductive member 20 to smoothly follow the movement of the inner surface rubber layer 10, enabling power transmission while maintaining durability. Furthermore, compared to when the knitted fabric is directly fixed to the inner surface rubber layer 10, stress on the knitted fabric can be alleviated, improving the durability of the conductive member 20. For example, when an adhesive is used to bond the knitted fabric to the inner surface rubber layer 10, the adhesive may impregnate the knitted fabric and harden, thereby inhibiting the stretchability of the knitted fabric or interfering with the movement of the knitted fabric and making the conductive yarns 23 more susceptible to breakage, but as described above, the elastomer 25 is exposed on at least one surface of the knitted fabric of the conductive member 20, and the conductive member 20 is bonded to the inner surface rubber layer 10 via the elastomer 25, thereby protecting the knitted fabric structure. Note that modes for fixing the conductive member 20 to the inner surface rubber layer 10 via the elastomer 25 include mechanical fixing, fixing with an adhesive, fixing with a pressure-sensitive adhesive, fixing by vulcanization adhesion, etc.

[0032] In the above tire, the elastomer 25 preferably contains a diene rubber. The diene rubber preferably has a glass transition temperature Tg in the range of -80°C to 0°C. The diene rubber has sufficient elongation, and therefore can effectively improve the durability of the conductive member 20. Furthermore, when the inner surface rubber layer 10 of the tire contains butyl rubber, the use of a diene rubber for the elastomer 25 that fills the spaces in the knitted fabric can improve the adhesion between the conductive member 20 and the inner surface rubber layer 10. When the elastomer 25 contains a diene rubber, it is preferable that it does not contain a carbon reinforcing material, that its elastic modulus is lower than that of the inner surface rubber layer 10, and that its breaking elongation is in the range of 500% to 900%.

[0033] In the above tire, as shown in Fig. 1, it is preferable that at least a part of the conductive member 20 is disposed in a flex zone Fx defined between a perpendicular line extending from an end of the belt layer 7 embedded in the tread portion 1 to the tire inner surface S and a perpendicular line extending from an outer diameter side end of the bead core 5 embedded in the bead portion 3 to the tire inner surface S. In the present invention, the tension applied to the conductive thread 23 due to tire deformation can be alleviated, and therefore a significant effect can be achieved when at least a part of the conductive member 20 is disposed in the flex zone Fx where deformation of the tire inner surface S is relatively large.

[0034] When the conductive member 20 is arranged so as to cross the flex zone FX, it is preferable that the conductive member 20 has a terminal 30 outside the flex zone Fx that is electrically connected to the conductive thread 23. In Fig. 1, the terminals 30 are provided at a portion of the conductive member 20 that is outer than the flex zone FX in the tire radial direction and at a portion of the conductive member 20 that is inner than the flex zone FX in the tire radial direction. Because the terminal 30 that is electrically connected to the conductive thread 23 is a portion that is prone to breakage due to tire deformation, arranging the terminal 30 outside the flex zone Fx can increase the durability of the conductive member 20.

[0035] In the tire described above, when the conductive member 20 has a terminal 30 electrically connected to the conductive thread 23 as shown in Fig. 5, it is preferable that the region including the terminal 30 is not filled with the elastomer 25. In other words, it is preferable that the region X1 of the conductive member 20 that is separated from the terminal 30 is filled with the elastomer 25. If the region including the terminal 30 is also filled with the elastomer 25 and, as a result, the terminal 30 is covered with the elastomer 25, it becomes difficult to solder a wiring member to the terminal 30.

[0036] In the above tire, as shown in Fig. 6 , when the conductive member 20 has a terminal 30 electrically connected to the conductive thread 23 and a wiring member 31 pre-connected to the terminal 30, it is preferable that the region including the terminal 30 is also filled with elastomer 25. In other words, it is preferable that the entire region X2 including the terminal 30 of the conductive member 20 is filled with elastomer 25. When the conductive member 20 has the terminal 30 and the wiring member 31 already connected to the terminal 30, even if the region including the terminal 30 is filled with elastomer 25, there is no need to worry about poor soldering between the terminal 30 and the wiring member 31.

[0037] Next, a method for manufacturing the above-mentioned pneumatic tire will be described. First, an unvulcanized tire is molded, which includes the carcass layer 4, bead cores 5, bead fillers 6, belt layers 7, belt cover layers 8, and an inner surface rubber layer 10. Meanwhile, the conductive member 20 is impregnated with an elastomer 25, and the elastomer 25 is dried. Then, in the unvulcanized tire, the conductive member 20 filled with the elastomer 25 is attached to the inner surface rubber layer 10. Next, the unvulcanized tire is vulcanized together with the conductive member 20. This allows for efficient manufacturing of a tire including the conductive member 20, and also increases the durability of the conductive member 20.

[0038] The tire manufacturing method described above is a preferred method, but is not limited to this. For example, it is also possible to attach the conductive member 20 to the inner surface rubber layer 10 after vulcanizing the tire by a conventional method.

[0039] 7 to 9 each show a manufacturing process for a conductive member used in the present invention. In FIGS. 7 to 9, a liquid elastomer 35, typically natural rubber latex, is stored in a bath 36. In FIG. 7, a long conductive member 20 is continuously immersed in the liquid elastomer 35 to fill the conductive member 20 with the elastomer 25, and then the conductive member 20 is cut to a predetermined length. In FIG. 8, when the conductive member 20 cut to a predetermined length has a terminal 30 electrically connected to the conductive thread 23, only a region X1 of the conductive member 20 outside the terminal 30 is immersed in the liquid elastomer 35 to fill the conductive member 20 with the elastomer 25. In Figure 9, when a conductive member 20 cut to a predetermined length has a terminal 30 electrically connected to a conductive thread 23 and a wiring member 31 pre-connected to the terminal 30, the entire area X2 of the conductive member 20 including the terminal 30 is immersed in liquid elastomer 35, thereby filling the conductive member 20 with elastomer 25.

[0040] FIG. 10 shows an example of the arrangement of electronic devices in a pneumatic tire, and FIG. 11 shows a connection structure between the electronic device and a conductive member. In FIG. 10, an electronic device 40 is installed on the tire inner surface S, and the electronic device 40 is located at a position on the tire center line CL. One end of a conductive member 20 arranged on the inner surface rubber layer 10 is electrically connected to the electronic device 40, and the other end extends toward the bead portion 3. As shown in FIG. 11, the electronic device 40 includes a substrate 41, a pair of terminals 42 mounted on the substrate 41, various electronic components 43 mounted on the substrate 41, and wiring 44 connecting the terminals 42 and the electronic components 43 to each other. The electronic device 40 is electrically connected to a pair of conductive portions 21 of the conductive member 20 via the pair of terminals 42. The distance between the pair of terminals 42 in the electronic device 40 is preferably equal to the distance between the pair of conductive portions 21 in the conductive member 20. In this case, the terminals 42 of the electronic device 40 and the conductive portions 21 of the conductive member 20 can be directly connected by soldering or the like without using any other electric wires.

[0041] 12 to 14 each show an example of the arrangement of an electronic device in a pneumatic tire. As shown in FIGS. 12 to 14, an electronic device 40 is installed on the tire inner surface S, and a conductive member 20 is arranged to extend from the electronic device 40 along the tire inner surface S. In FIG. 12, wide conductive members 20 are connected to both sides in the tire width direction of a large electronic device 40 that requires relatively large amounts of power, and each conductive member 20 is used as positive or negative wiring. In FIGS. 13 and 14, a conductive member 20 is connected to one side in the tire width direction of a small electronic device 40 that operates with relatively small amounts of power, and each conductive portion 21 of the conductive member 20 is used as positive or negative wiring. In FIG. 13, the conductive member 20 extends in the tire width direction, whereas in FIG. 14, the conductive member 20 extends in a direction oblique to the tire width direction. [Example]

[0042] Tires of Examples 1 to 5 were manufactured with a tire size of 245 / 40R19 and equipped with an inner surface rubber layer that forms the inner surface of the tire and a conductive member disposed on the inner surface rubber layer, using a conductive member made of a stretchable knitted fabric including a conductive portion made of conductive yarn and a non-conductive portion made of non-conductive yarn, and filling at least a portion of the conductive portion made of conductive yarn with an elastomer that fills the space in the knitted fabric, with the type of elastomer and the volume fraction of the elastomer in the total volume of the conductive member filled with the elastomer set as shown in Table 1. Also prepared was a tire of Comparative Example 1 in which the conductive member was not filled with elastomer.

[0043] In Examples 1 to 5, natural rubber (A), silicone rubber (B) or urethane elastomer (C) was used as the elastomer.

[0044] The durability of the conductive members of these test tires was evaluated by the following evaluation method, and the results are shown in Table 1.

[0045] Conductive material durability: Each test tire was mounted on a wheel with a rim size of 19x8J, the air pressure was set to 150 kPa, and the tire was mounted on a drum testing machine with a smooth steel drum surface and a diameter of 1707 mm. A 3000 km running test was conducted under conditions of a speed of 120 km / h and a load of 100% of the JATMA maximum load, while the ambient temperature was controlled at 38±3°C. After the running test, the electrical resistance of the entire conductive member (the resistance value measured between both ends of the conductive member with the ends of all conductive parts shorted together) was measured. The evaluation results were expressed as an index using the reciprocal of the measured value, with Comparative Example 1 being set at 100. A higher index value indicates better durability of the conductive member.

[0046] [Table 1]

[0047] As can be seen from Table 1, in comparison with Comparative Example 1, the durability of the conductive members of the tires of Examples 1 to 5 was improved.

[0048] The present disclosure includes the following inventions [1] to [9]. Invention [1] is a tire having an inner surface rubber layer that constitutes the inner surface of the tire, and a conductive member disposed on the inner surface rubber layer, The tire is characterized in that the conductive member is made of a stretchable knitted fabric, at least a portion of which is made of conductive yarn, and at least a portion of the conductive portion made of the conductive yarn is filled with an elastomer that fills the spaces in the knitted fabric. Invention [2] is the tire according to invention [1], characterized in that the conductive yarn is a metal wire with an insulating coating. Invention [3] is a tire according to invention [1] or [2], characterized in that the elastomer is exposed on at least one surface of the knitted fabric, and the conductive member is fixed to the inner surface rubber layer via the elastomer. Invention [4] is the tire according to invention [3], characterized in that the elastomer contains a diene rubber. Invention [5] is a tire according to any one of inventions [1] to [4], characterized in that at least a part of the conductive member is arranged in a flex zone defined between a perpendicular line extending from an end of a belt layer embedded in a tread portion to the tire inner surface and a perpendicular line extending from an outer diameter side end of a bead core embedded in a bead portion to the tire inner surface. Invention [6] is a tire according to invention [5], characterized in that the conductive member is arranged across the flex zone and has a terminal outside the flex zone that is electrically connected to the conductive yarn. Invention [7] is a tire according to any one of inventions [1] to [6], characterized in that the conductive member has a terminal electrically connected to the conductive thread, and the elastomer is not filled in the area including the terminal. Invention [8] is a tire according to any one of inventions [1] to [6], characterized in that the conductive member has a terminal electrically connected to the conductive thread and a wiring member connected to the terminal, and the elastomer is also filled in the area including the terminal. Invention [9] is a method for producing a tire according to any one of Inventions [1] to [8], a step of molding an unvulcanized tire having the inner surface rubber layer; impregnating the conductive member with an elastomer and drying the elastomer; attaching the conductive member to the inner surface rubber layer; and vulcanizing the unvulcanized tire together with the conductive member. [Explanation of symbols]

[0049] 1 Tread section 2 Sidewall 3 Bead section 4 carcass layers 5 bead core 6 Bead filler 7 Belt Layer 8 Belt cover layer 10 Inner surface rubber layer 20 Conductive material 21 Conductive part 22 Non-conductive parts 23 Conductive thread 24 Non-conductive thread 25 Elastomer 30 terminals 31 Wiring materials 40 Electronic Devices

Claims

1. A tire comprising an inner surface rubber layer that forms an inner surface of the tire, and a conductive member disposed on the inner surface rubber layer, The tire is characterized in that the conductive member is made of a stretchable knitted fabric, at least a portion of which is made of conductive yarn, and at least a portion of the conductive portion made of the conductive yarn is filled with an elastomer that fills spaces in the knitted fabric.

2. 2. The tire according to claim 1, wherein the conductive thread is a metal wire with an insulating coating.

3. 2. The tire according to claim 1, wherein the elastomer is exposed on at least one surface of the knitted fabric, and the conductive member is fixed to the inner surface rubber layer via the elastomer.

4. 4. The tire of claim 3, wherein the elastomer comprises a diene-based rubber.

5. 2. The tire according to claim 1, wherein at least a portion of the conductive member is disposed in a flex zone defined between a perpendicular line extending from an end of a belt layer embedded in a tread portion to the tire inner surface and a perpendicular line extending from an outer diameter side end of a bead core embedded in a bead portion to the tire inner surface.

6. 6. The tire according to claim 5, wherein the conductive member is disposed across the flex zone and has a terminal electrically connected to the conductive yarn outside the flex zone.

7. The tire according to claim 1, wherein the conductive member has a terminal electrically connected to the conductive thread, and the elastomer is not filled in an area including the terminal.

8. The tire according to claim 1, characterized in that the conductive member has a terminal electrically connected to the conductive thread and a wiring member connected to the terminal, and the elastomer is also filled in an area including the terminal.

9. A method for manufacturing a tire according to any one of claims 1 to 8, a step of molding an unvulcanized tire having the inner surface rubber layer; impregnating the conductive member with an elastomer and drying the elastomer; attaching the conductive member to the inner surface rubber layer; A tire manufacturing method comprising: vulcanizing the unvulcanized tire together with the conductive member.

Images