Tire with sealant and tire puncture sensor system

Abstract

In one aspect, the invention relates to a tire comprising a circumferential tread portion and an inner surface partially surrounding a tire cavity, and a circumferential sealant layer disposed at least partially on the inner surface radially below the tread portion. Further, the tire includes a first conductive layer at least partially covering a surface of the sealant layer, and a second conductive layer non-conductively separated from the first conductive layer. A sensor system of the tire is in electrical contact with the first and second electrically conductive layers, respectively, wherein the sensor system is further configured to detect an increase in conductivity or a short circuit between the first and second electrically conductive layers.

Description

Technical Field

[0001] The invention relates to a tire, in particular a pneumatic tire, comprising a sealant layer and a sensor system, in particular for detecting punctures of the tire and / or the sealant layer. Background Art

[0002] Tire robustness has improved significantly over the past several decades. Providing a sealant layer, among other methods, helps maintain tire inflation pressure even in the event of a tire puncture (usually caused by a nail or screw). However, at least in some cases, a driver of a vehicle with a sealant-equipped tire that has been punctured may not notice the puncture and may continue to drive with the tire punctured for a relatively long time. It may be desirable to notify the driver and / or vehicle owner of the tire puncture. Thus, while progress has been made in the development of puncture-resistant tires, there is still room for improvement. Summary of the invention

[0003] In a first aspect of the invention, the invention relates to a tire comprising a circumferential tread portion and an inner surface partially surrounding a tire cavity. In addition, the tire comprises a circumferential sealant layer, which is at least partially arranged on the inner surface radially below the tread portion. The sealant layer has a radial inner side and a radial outer side. In addition, the tire comprises a first conductive layer, which at least partially covers one side of the sealant layer. In addition, the tire has a second conductive layer, which is substantially arranged parallel to the first conductive layer and is non-conductively separated from the first conductive layer. Still according to the first aspect, the tire comprises a sensor system that is electrically in contact with the first conductive layer and the second conductive layer, respectively, and the sensor system is suitable for detecting an increase in conductivity between the first conductive layer and the second conductive layer.

[0004] In a second aspect of the invention, the invention relates to a tire comprising a circumferential tread portion and an inner surface partially surrounding a tire cavity. In addition, the tire comprises a circumferential sealant layer, which is at least partially arranged on the inner surface radially below the tread portion, and a first conductive layer, which at least partially covers the radial inner surface of the sealant layer. In particular, the volume resistivity of the sealant layer is at least 100 times the volume resistivity of the first conductive layer. In addition, the tire comprises a second conductive layer arranged radially above the sealant layer, and a sensor system electrically contacting the first conductive layer and the second conductive layer, respectively. The sensor system is suitable for detecting a short circuit between the first conductive layer and the second conductive layer. Still according to the second aspect, the sensor system comprises a transmitter, which is suitable for wirelessly transmitting a signal informing of a detected short circuit.

[0005] The present invention provides the following technical solutions:

[0006] 1. A tire, comprising:

[0007] Circumferential tread portion;

[0008] Partially surrounding the inner surface of the tire cavity;

[0009] a circumferential sealant layer disposed at least partially on the inner surface radially below the tread portion, wherein the sealant layer has a radially inner side and a radially outer side;

[0010] a first conductive layer at least partially covering one side of the sealant layer;

[0011] a second conductive layer, the second conductive layer being arranged substantially parallel to the first conductive layer and being non-conductively separated from the first conductive layer; and

[0012] A sensor system is in electrical contact with the first and second conductive layers, respectively, and is adapted to detect an increase in conductivity between the first and second conductive layers.

[0013] 2. The tire according to claim 1, wherein the first conductive layer comprises one or more of a conductive coating, a conductive foil, a conductive mesh, a conductive fabric, a plurality of conductive wires, and a conductive elastomer composition.

[0014] 3. The tire according to claim 1, wherein at least one of the first conductive layer and the second conductive layer comprises one or more of a metal coating, a metal foil, a metal mesh, a plurality of conductive metal wires, and a conductive rubber composition.

[0015] 4. The tire according to claim 1, wherein the first conductive layer has a thickness in the range of 0.1 mm to 1 mm.

[0016] 5. The tire according to claim 1, wherein the sealant layer has a thickness in the range of 1 mm to 8 mm.

[0017] 6. The tire according to claim 1, wherein the sealant layer comprises an elastomeric composition comprising:

[0018] From 80 to 100 phr of rubber, which is selected from one or more of butyl rubber, halogenated butyl rubber, EPDM rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylonitrile-butadiene-styrene rubber, polybutadiene rubber, natural rubber, and synthetic polyisoprene;

[0019] From 20 phr to 100 phr of filler; and

[0020] From 150 to 600 phr of a liquid plasticizer selected from one or more of oils, liquid polymers and polyisobutylene.

[0021] 7. The tire according to claim 1, wherein the sealant layer comprises an elastomeric composition comprising:

[0022] From 80 to 100 phr of a rubber selected from butyl rubber and halogenated butyl rubber;

[0023] From 20 phr to 90 phr of filler, including one or more of carbon black and silica; and

[0024] From 300 to 600 phr of a liquid plasticizer selected from one or more of oils, liquid polymers and polyisobutylene.

[0025] 8. The tire according to claim 1, wherein each conductive layer extends over at least 70% of the area of ​​the adjacent surface of the sealant layer.

[0026] 9. The tire according to claim 1, wherein the tire comprises one or more of the following:

[0027] i) an inner liner forming at least part of the inner surface of the tire, comprising an electrically conductive rubber composition,

[0028] ii) a belt layer arranged radially between the sealant layer and the tread portion and comprising a conductive rubber composition,

[0029] iii) a covering layer comprising a conductive rubber composition,

[0030] iv) a tread base layer comprising a conductive rubber composition, and

[0031] v) a tread portion comprising a layer of electrically conductive rubber composition extending axially over at least 90% of the axial width of the tire's footprint; and

[0032] At least one of the conductive rubber compositions forms a second conductive layer.

[0033] 10. The tire according to claim 1, wherein one or more of the first conductive layer and the second conductive layer are electrically insulating.

[0034] 11. The tire according to claim 1, wherein the first conductive layer is arranged radially inward of the sealant layer, and wherein the sealant layer comprises an elastomeric composition having a volume resistivity at least 100 times that of the first conductive layer.

[0035] 12. The tire according to claim 11, wherein the second conductive layer is arranged radially outside the sealant layer.

[0036] 13. The tire according to claim 1, wherein the sensor system comprises a measurement circuit suitable for detecting a short circuit between the first conductive layer and the second conductive layer.

[0037] 14. The tire of claim 13, wherein the sensor system further comprises a transmitter, and wherein the sensor system is configured to wirelessly transmit information about the short circuit detected by the measurement circuit via the transmitter.

[0038] 15. The tire of claim 14, wherein the measurement circuit comprises a sensor arranged and configured to determine a current between the first conductive layer and the second conductive layer.

[0039] 16. The tire according to claim 13, wherein the measurement circuit includes a first insulated wire and a second insulated wire, and wherein the measurement system is electrically connected to the first conductive layer via the first wire and is electrically connected to the second conductive layer via the second wire.

[0040] 17. A tire according to claim 15, wherein the sensor system includes a sensor transmitter unit carrying the sensor and the transmitter, and wherein the sensor transmitter unit is attached at one or more of i) an inner surface in the sidewall area of ​​the tire and ii) a position radially below the sealant layer.

[0041] 18. The tire according to claim 17, wherein the tire further comprises an elastomeric composition-based container carrying the sensor transmitter unit, and wherein the container is attached to the inner surface in the sidewall region of the tire.

[0042] 19. The tire of claim 15, wherein the sensor system comprises an RFID tag comprising a sensor and a transmitter.

[0043] 20. A tire comprising:

[0044] Circumferential tread portion;

[0045] partially surrounding an inner surface of a tire cavity;

[0046] a circumferential sealant layer disposed at least partially on the inner surface radially below the tread portion;

[0047] a first conductive layer at least partially covering a radially inner surface of the sealant layer, wherein the sealant layer has a volume resistivity at least 100 times greater than a volume resistivity of the first conductive layer;

[0048] a second conductive layer disposed radially above the sealant layer; and

[0049] A sensor system is in electrical contact with the first conductive layer and the second conductive layer, respectively, and is adapted to detect a short circuit between the first conductive layer and the second conductive layer, and further comprises a transmitter configured to wirelessly transmit a signal informing of the detected short circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0051] Figure 1 is a schematic cross-sectional view of a tire according to one embodiment of the present invention;

[0052] Figure 2 is based on Figure 1 A schematic cross section of a tire of the type shown in FIG. 1 , wherein the tire is punctured by a screw and a signal regarding the detected tire puncture is transmitted;

[0053] Figure 3 is a schematic cross-sectional view of a tire according to another embodiment of the present invention;

[0054] Figure 4 is based on Figure 3 a schematic cross section of a tire of , wherein the respective tire is punctured by a nail and a signal regarding the detected tire puncture is transmitted;

[0055] Figure 5 is a schematic cross-section of a tire according to another embodiment of the present invention, wherein the tire includes an RFID tag attached to its sidewall and notifying of tire punctures;

[0056] Figure 6 It is used for detection Figure 1 and Figure 2 A schematic circuit diagram of a measurement circuit for a short circuit between a first conductive layer and a second conductive layer of the illustrated embodiment;

[0057] Figure 7 yes Figure 6 Another schematic circuit diagram of the measuring circuit already shown in , wherein the measuring circuit is closed by a metal screw connecting two conductive layers;

[0058] Figure 8 is yet another schematic cross-section of a tire according to another embodiment of the present invention, wherein two conductive layers are arranged radially one on top of the other radially inside the sealant layer; and

[0059] Fig. 9 is Figure 8 A schematic plan view in the radial direction of the two layers already shown. DETAILED DESCRIPTION

[0060] According to a first aspect, the present invention relates to a tire (preferably a pneumatic tire) comprising a circumferential tread portion and an inner surface partially surrounding a tire cavity. In addition, the tire comprises a circumferential sealant layer, which is at least partially arranged on the inner surface radially below (or inside) the tread portion. The sealant layer has a radially inner side or surface and a radially outer side or surface. The tire also includes a first conductive layer, which at least partially covers one side or surface of the sealant layer. In addition, the tire has a second conductive layer, which is substantially arranged or arranged parallel to the first layer and is non-conductively separated from the first conductive layer. Still according to the first aspect, the tire comprises a sensor system, which is in electrical contact with the first conductive layer and in separate electrical contact with the second conductive layer, and the sensor system is suitable or configured to detect an increase in conductivity between the first conductive layer and the second conductive layer (in particular, suitable for detecting an electric current or an electrical short circuit).

[0061] In particular, the present invention allows for the detection of and provision of information regarding a tire puncture. For example, typically, a metal nail or screw may penetrate a tire tread portion and a sealant layer. Such a conductive metal nail or screw electrically connects a first conductive layer to a second conductive layer, which is detected by a sensor system. While a sealant such as this may seal the tire to prevent loss of air pressure, the driver and / or vehicle may also be informed that the tire appears to have a puncture and may need to be modified, repaired, and replaced, for one or more.

[0062] In one embodiment, the first conductive layer comprises one or more of a conductive coating, a conductive foil, a conductive mesh, a conductive fabric, a plurality of conductive wires (e.g., substantially parallel wires) and a conductive elastomer composition layer. It is possible that the first layer is disposed on the radially inner side or surface of the sealant layer, or disposed on the radially outer side or surface of the sealant layer. The conductive coating may include or consist of a metal and may be applied by methods known in the art, such as plasma coating. Coating with a metal powder is also an option. The conductive foil is, for example, a metal foil, which may optionally adhere to the sealant layer without the need for additional adhesive, for example due to the typical viscosity of the sealant composition. The conductive mesh may be a metal mesh or a grid. It is also possible that the mesh comprises wires and / or fibers of a textile material comprising a conductive metal or polymer (e.g., rubber) composition coating. Such a mesh may again be carried by the sealant layer without the need for additional adhesive. The mesh opening preferably has a maximum diameter of 1 mm. The adjacent wires of a plurality of adjacent wires (e.g., a plurality of substantially parallel wires) preferably have a distance of up to 1 mm, which is measured perpendicular to the parallel extension of the wires. The conductive fabric may include metal wires and / or fibers, or may be a woven fabric coated with metal and / or a conductive elastomer composition (e.g., a rubber composition). The conductive elastomer composition layer (preferably a rubber composition layer) may include one or more elastomers or rubbers, such as natural rubber, synthetic polyisoprene, polybutadiene rubber, and styrene-butadiene rubber. In addition, such a composition may include at least 35 phr of carbon black, preferably at least 38 phr, more preferably at least 40 phr, or at least 45 phr of carbon black.

[0063] In another embodiment, at least one of the first conductive layer and the second conductive layer includes one or more of a metal coating, a metal foil, a metal mesh, a metal-coated textile mesh, a metal-coated fabric, a plurality of conductive metal wires (e.g., substantially parallel wires), and a conductive rubber composition.

[0064] In another embodiment, the second conductive layer is disposed radially above or outside the first conductive layer.

[0065] In yet another embodiment, the second conductive layer is one or more of: i) electrically separated, ii) non-conductively separated, and iii) spatially separated from the first conductive layer, and / or vice versa. Optionally, the second conductive layer is electrically insulated from the first conductive layer, and / or vice versa.

[0066] In yet another embodiment, the first conductive layer and the second conductive layer are spatially separated from each other.

[0067] In yet another embodiment, the first conductive layer and the second conductive layer are non-conductive and spatially separated from each other. In particular, they may be separated by a non-conductive material, such as one or more of a non-conductive polymer composition, a non-conductive layer, and a non-conductive rubber composition layer.

[0068] In another embodiment, the (maximum) axial width of at least one conductive layer (preferably the radially inner conductive layer) is at least 1% smaller than the (maximum) axial width of the sealant layer, for example, axially smaller than the (maximum) axial width of the sealant layer by 1% to 10%, preferably from 1% to 5%. Preferably, this applies to the case of a non-conductive sealant layer.

[0069] In another embodiment, each axially outer edge of the one or more conductive layers is located at an axial distance from an adjacent axially outer edge of the sealant layer in a range of 0.5% to 5% of the maximum axial width of the sealant layer.

[0070] In yet another embodiment, the thickness of the first conductive layer is in the range of 0.1 mm to 2 mm, preferably 0.1 mm to 1.5 mm. If it is a metal foil or coating, the thickness is preferably in the range of 0.1 mm to 0.9 mm. Unless otherwise specified herein, the layer thickness is measured in the radial direction.

[0071] In yet another embodiment, the thickness of the sealant layer is in the range of 1 mm to 8 mm, preferably in the range of 2.5 mm to 5.5 mm.

[0072] In yet another embodiment, the sealant layer comprises an elastomeric composition, preferably a rubber composition, comprising one or more of the following:

[0073] From 60 phr, preferably from 80 phr to 100 phr of rubber, the rubber is selected from one or more of butyl rubber, halogenated butyl rubber, EPDM rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylonitrile-butadiene-styrene rubber, polybutadiene rubber, natural rubber, and synthetic polyisoprene;

[0074] From 20phr to 100phr of filler;

[0075] From 150 phr to 600 phr of a liquid plasticizer selected from one or more of oils, liquid polymers and polyisobutylene.

[0076] The term "liquid" herein means that the material is in a liquid state at a temperature of 23°C.

[0077] In yet another embodiment, the sealant layer comprises a rubber composition comprising one or more of the following:

[0078] From 80 to 100 phr of a rubber selected from butyl rubber and halogenated butyl rubber;

[0079] From 20 phr to 90 phr of filler, including one or more of carbon black and silica; and

[0080] From 300 to 600 phr of a liquid plasticizer selected from one or more of oils, liquid polymers (preferably liquid diene-based polymers) and polyisobutylene.

[0081] Preferably, the rubber composition of the sealant layer comprises from 300 to 600 phr of polyisobutene (also known as polyisobutylene). Preferably, the sealant layer is a peroxide cured sealant layer.

[0082] In yet another embodiment, the sealant layer includes a rubber composition and / or features as disclosed in US Patent Application Publication No. US2016 / 0068031A1 and / or US Pat. No. US10,870,319B2, which are incorporated herein by reference.

[0083] In yet another embodiment, at least one conductive layer (preferably each conductive layer) extends over at least 70% of the area of ​​the adjacent surface of the sealant layer, preferably continuously extending over at least 70%, preferably at least 80% or at least 90% of the maximum axial width of the radially inner surface of the sealant layer. In addition, or alternatively, one or both conductive layers extend substantially parallel to the sealant layer.

[0084] In yet another embodiment, the second conductive layer comprises one or more of i) a metal coating, ii) a metal foil, and iii) a metal mesh, with a thickness in the range of 0.1 mm to 1 mm. Additionally, or alternatively, one option is that the second conductive layer has the same features as described above with respect to the first conductive layer.

[0085] In yet another embodiment, the tire comprises one or more of the following:

[0086] i) an inner liner forming (at least a portion of) the inner surface of the tire, comprising an electrically conductive rubber composition,

[0087] ii) a belt layer arranged radially between the sealant layer and the tread portion and comprising an electrically conductive rubber composition and optionally metal wires coated with the electrically conductive rubber composition,

[0088] iii) a covering layer comprising a conductive rubber composition, preferably a textile thread and / or one or more textile fabrics coated with a conductive rubber composition,

[0089] iv) a tread base layer comprising or consisting of an electrically conductive rubber composition (wherein, optionally, the tread base layer is disposed radially below a crown layer of the tread portion, and wherein the crown layer contacts the road during running), and

[0090] v) A tread portion comprising an electrically conductive rubber layer extending axially over at least 90% of the axial footprint width of the tire. In this context, this footprint width is measured at maximum tire load (as shown on the tire sidewall), 2.5 bar pressure and 23°C.

[0091] Optionally, at least one of the conductive rubber compositions forms a second conductive layer. In other words, at least one of the above listed components i), ii), iii), iv) and v) may form a second conductive layer.

[0092] In another embodiment, the first conductive layer is disposed on one of the radially inner side (or surface) and the radially outer side (or surface) of the sealant layer.

[0093] In yet another embodiment, the first conductive layer and the second conductive layer are arranged on the same side or surface of the sealant layer. Optionally, the first layer and the second layer are adjacent. In this case, at least one of these layers is preferably electrically insulating.

[0094] In yet another embodiment, one or more of the first and second conductive layers are electrically insulating.Preferably, one or more of the first and second conductive layers comprises electrical insulation, or in other words comprises one or more of an electrically insulating coating and an electrically insulating shell.

[0095] In yet another embodiment, one or more of the first conductive layer and the second conductive layer extend circumferentially in the tire.

[0096] In yet another embodiment, the first conductive layer is arranged radially inwardly (or on the surface) of the sealant layer, and / or the sealant layer comprises an elastomeric composition (preferably a rubber composition) having a volume resistivity at least 100 times that of the first conductive layer, and optionally 100 times that of the second conductive layer. Optionally, the sealant layer and / or its elastomer, particularly the rubber composition, may be described as non-conductive.

[0097] If the material or composition has less than 10 8 ohm·cm, optionally less than 10 7 ohm·cm, then the material or composition is considered to be conductive herein. For example, metals have much lower volume resistivities, optionally below 10 - 6 ohm·cm to 10 -3ohm·cm range and is conductive. Volume resistivity is determined herein in accordance with ASTM D257-98 or an equivalent standard. Alternatively, if a material or composition has a volume resistivity greater than 10 9 ohm·cm, preferably higher than 10 10 ohm·cm, then the material or composition is considered non-conductive herein.

[0098] In yet another embodiment, the second conductive layer is disposed radially outside (or on the surface) of the sealant layer.

[0099] In yet another embodiment, the two conductive layers are electrically separated from each other (or in other words, non-conductively separated), for example, by at least one non-conductive layer. For example, such a layer can be one or more of a sealant layer, an inner liner, a belt layer, a cover layer, and a tread base layer. However, it can also be any other type of non-conductive polymer composition layer. In one embodiment, the non-conductive layer includes a non-conductive rubber composition as described above. One method known to those skilled in the art to make a rubber composition conductive or non-conductive is to adjust the carbon black content of the rubber composition, wherein a higher carbon black content can increase the conductivity, while a lower carbon black content can reduce the conductivity of the rubber composition. Conductive and non-conductive rubber compositions such as these suitable for use in the above-mentioned layers are known in the art.

[0100] In yet another embodiment, the sensor system is adapted to and / or comprises a measuring circuit adapted to detect one or more of a current, an increase in current and a short circuit between the first conductive layer and the second conductive layer. In particular, a short circuit between these layers may be detected. The terms "adapted to" and "configured to" are used interchangeably herein.

[0101] In yet another embodiment, the sensor system and / or the measuring circuit is adapted to detect a short circuit between the first conductive layer and the second conductive layer. Additionally or alternatively, the measuring circuit may also be referred to herein as a sensor circuit, for example for detecting a short circuit between the first conductive layer and the second conductive layer.

[0102] In yet another embodiment, the sensor system comprises a power supply (preferably a DC power supply, or, alternatively, an AC power supply). Optionally, a first pole of the power supply is electrically connected to the first conductive layer, and a second pole of the power supply is electrically connected to the second conductive layer. In particular, a short circuit between the first conductive layer and the second conductive layer (e.g., a short circuit caused by a metal object electrically piercing and / or connecting the first conductive layer and the second conductive layer) results in a current or an increased current (e.g., a short circuit) between the first conductive layer and the second conductive layer. In other words, such a metal object penetrating or piercing the two conductive layers can also be regarded as an electrical switch, closing the circuit between the first conductive layer and the second conductive layer. Optionally, one or more resistors can be arranged in the electrical path between the first pole and one or more of the first conductive layer and / or the second pole and the second conductive layer.

[0103] In yet another embodiment, the sensor system further comprises a transmitter, wherein the sensor system is configured to wirelessly transmit information about or indicating the detected short circuit via the transmitter. For example, the transmitter is adapted to transmit the information about or indicating the detected short circuit via Bluetooth. TM , wireless networks, radio waves or other wireless transmission technologies. Similarly, the receivers mentioned herein may be adapted to transmit signals wirelessly via Bluetooth. TM , wireless networks, radio waves, or other wireless transmission technologies.

[0104] In another embodiment, the measuring circuit comprises a sensor, which is arranged and adapted to determine the current between the first conductive layer and the second conductive layer. This does not mean that the sensor is physically located between the two conductive layers. Instead, the sensor is, for example, arranged in the measuring circuit to (electrically) connect the first conductive layer and the second conductive layer.

[0105] In yet another embodiment, the sensor system (particularly the measuring circuit) comprises a first insulated wire and a second insulated wire, wherein the sensor system (particularly the measuring circuit) is electrically connected or communicates with the first conductive layer via the first wire and is electrically connected or communicates with the second conductive layer via the second wire. For example, such wires may be insulated wires. They may be at least partially attached to the inner surface of the tire, for example to the inner liner. However, this feature is not mandatory.

[0106] In yet another embodiment, the sensor system comprises a sensor transmitter unit carrying the sensor and the transmitter, for example in a common housing of the sensor transmitter unit. Preferably, the sensor transmitter unit is attached to the inner surface in the sidewall region of the tire. The sensor transmitter unit may also be a tag, for example an RFID tag discussed further below.

[0107] In yet another embodiment, the tire and / or the sensor system further comprises a container (e.g. a polymer composition based container, e.g. an elastomeric composition based container, preferably a rubber composition based container) which carries and / or partially surrounds the sensor transmitter unit. In particular, the container may at least partially surround the housing of the sensor transmitter unit.

[0108] In another embodiment, the sensor system and / or the sensor transmitter unit further comprises one or more of a power supply, a processing unit, a receiver and a memory. In particular, it may comprise one or more of a plurality of power supplies (e.g., one power supply for the measuring circuit and a separate power supply for the transmitter), a processing unit, a receiver and a memory (e.g., a rewritable memory and a non-rewritable memory for recording information received by the sensor, which may, for example, include information about the sensor system).

[0109] In yet another embodiment, the container is attached to the inner surface by an adhesive and / or is co-cured with the inner surface.Alternatively, the sensor transmitter unit is adhered directly to the inner surface of the tire, for example by an adhesive.

[0110] In yet another embodiment, a tire comprises a sensor transmitter unit comprising a sensor, a transmitter, and optionally a power source, wherein the sensor transmitter unit is carried by a container attached to an inner surface of the tire.

[0111] In yet another embodiment, the sensor system (optionally, the sensor transmitter unit) further comprises a tire pressure sensor. Optionally, the tire pressure sensor is also part of the sensor transmitter unit. As a further option, it can also be carried by the container. The sensor system can also be adapted to wirelessly transmit information detected by the tire pressure sensor via a transmitter (e.g., a transmitter of the sensor transmitter unit).

[0112] In yet another embodiment, the sensor system comprises a radio frequency identification (RFID) tag. Optionally, the RFID tag comprises one or more of a sensor, a transmitter, a receiver, a memory, a processing unit and a power supply.

[0113] In yet another embodiment, the power source comprises or consists of a battery.

[0114] In yet another embodiment, the power source is supplied by another external power source, such as an external RFID reader.

[0115] In another embodiment, the RFID tag is configured to detect, by its sensor (preferably when triggered by an RFID reader device), whether there is an increase in conductivity, in particular a short circuit between the first conductive layer and the second conductive layer. If such an increase in conductivity or a short circuit is detected, the RFID tag is adapted and / or configured to send a signal indicating the increase in conductivity or the short circuit to the RFID reader by its transmitter and / or to store information indicating the increase in conductivity or the short circuit in its memory (if any). For example, the RFID reader may be part of the vehicle, or may be a separate external reader, such as a handheld reader.

[0116] In yet another embodiment, the RFID tag is co-cured with the tire, for example with the inner liner and / or the inner surface.Preferably, the RFID tag is disposed on the sidewall of the tire.

[0117] In yet another embodiment, the RFID tag is attached to the inner surface (e.g., inner liner) of the tire at the sidewall portion of the tire. Additionally, or alternatively, the RFID tag is co-cured to the inner surface or attached to the inner surface with an adhesive. Attaching RFID tags to the inner surface of a tire like this is known in the art, for example from EP4019241 A2, which is incorporated herein by reference.

[0118] In yet another embodiment, the RFID tag is embedded and / or attached to the sealant layer. In such an embodiment, the RFID tag can be attached / adhered to the sealant layer after the tire is cured, for example.

[0119] In yet another embodiment, the RFID tag is attached to a conductive layer disposed on the radial inner side of the sealant layer. For example, adhesion may be performed using an adhesive. Alternatively, it is also possible that the conductive layer has a hole at the location of the RFID tag so that the RFID tag is directly adhered to and / or embedded in the sealant layer on the radial inner side of the sealant layer.

[0120] In yet another embodiment, the first conductive layer is a conductive foam layer. Optionally, the sensor transmitter unit and / or RFID tag is attached to the foam layer, for example by an adhesive, optionally embedded in the foam layer. The conductive foam layer may include one or more of a conductive polymer foam, a polymer foam coated with a conductive material (e.g., a metal), and a metal foam material. The metal coating may be applied as known in the art.

[0121] In yet another embodiment, the first conductive layer includes a first plurality of substantially parallel conductive lines, and the second conductive layer includes a second plurality of substantially parallel conductive lines arranged transversely to the first plurality of substantially parallel conductive lines.

[0122] In yet another embodiment, one or more of the first plurality of substantially parallel conducting wires and the second plurality of substantially parallel conducting wires are electrically insulated. In other words, preferably, each conducting wire of the respective plurality of conducting wires is insulated and / or surrounded by an electrical insulator.

[0123] In yet another embodiment, the first plurality of conductive wires and the second plurality of conductive wires are together arranged in a mesh and / or together form a mesh (or in other words, a web).

[0124] In yet another embodiment, the wires of the first plurality of substantially parallel wires and the wires of the second plurality of substantially parallel wires are at least partially interwoven with each other, optionally such that both layers form a mesh of interwoven wires or a mesh of braided wires.

[0125] In yet another embodiment, the wires of the first plurality of wires and the second plurality of wires extend transversely to each other in the web.

[0126] In yet another embodiment, the conductors of the first plurality of conductors and the second plurality of conductors extend substantially in parallel and / or alternate with respect to each other.

[0127] If a conductive nail or screw pierces the mesh, adjacent conductors of the first and second pluralities of conductors may become electrically connected, or electrically shorted, such as when the piercing nail or screw damages the insulation of the adjacent conductors.

[0128] According to a second aspect, the present invention relates to a tire, in particular a pneumatic tire, comprising a circumferential tread portion, an inner surface partially surrounding a tire cavity, and a circumferential sealant layer, which is at least partially arranged on the inner surface radially below the tread portion. Still according to the second aspect, the first conductive layer at least partially covers the radial inner surface of the sealant layer, and the second conductive layer is arranged radially above the sealant layer. In addition, the volume resistivity of the sealant layer is at least 100 times the volume resistivity of the first conductive layer and the optional second conductive layer. In addition, the tire includes a sensor system, which is in electrical contact with the first conductive layer and in separate electrical contact with the second conductive layer, and is suitable for detecting a short circuit between the first conductive layer and the second conductive layer, in particular when the first conductive layer and the second conductive layer are electrically short-circuited. In addition, the sensor system includes a transmitter, which is suitable for wirelessly transmitting a signal informing of a detected short circuit.

[0129] Such tires again offer the possibility of being informed of a tire puncture so that the tire can be checked and, if appropriate, repaired.

[0130] In another aspect, the present invention relates to a method of detecting and / or signaling a tire puncture using a tire according to the first or second aspect or one or more embodiments disclosed herein.

[0131] In yet another aspect, the present invention relates to a method for detecting and / or signaling a puncture in a tire, preferably in a tire according to one or more aspects or one or more embodiments mentioned herein.

[0132] In one embodiment, the method comprises the steps of monitoring the presence of one or more of an increase in conductivity and an electric current between a first conductive layer and a second conductive layer (preferably arranged substantially parallel to the first conductive layer), wherein the second conductive layer is non-conductively separated from the first conductive layer.

[0133] In another embodiment, the method comprises the steps of detecting a tire puncture by detecting one or more of an increase in electrical conductivity, an increase in current and a short circuit between a first conductive layer and a second conductive layer of the tire (preferably arranged substantially parallel to the first conductive layer), for example when the first conductive layer is electrically connected to the second conductive layer (e.g., due to a metal element penetrating and / or electrically connecting the two layers).

[0134] In another embodiment, the method further comprises the step of storing information about the detected tire puncture.

[0135] In yet another embodiment, the method further comprises the step of wirelessly transmitting information about the detected tire puncture, for example, upon an external wireless request (eg, received by a wireless reader).

[0136] It should be emphasized that all aspects, embodiments and features disclosed herein can be combined with each other.

[0137] Figure 1 A cross section of a tire 1 according to a preferred embodiment of the invention is shown. The tire 1 comprises a tread portion 10, two sidewalls 50 and two bead portions 40, each of which comprises a bead 41, an apex 43 and a chafer 42. In addition, the tire 1 comprises an inner liner 61, which forms an inner surface 60 of the tire 1 and partially surrounds the tire cavity. The tire 1 also comprises two carcass plies 62, 63 folded around each bead 41, as well as two belt layers 64, 65 and a cover layer 66 covering the belt layers 64, 65.

[0138] According to the present embodiment, the inner surface 60 of the tire 1 or the inner surface 60 of the inner liner 61 carries a sealant layer 20 radially below the tread portion 10 and / or the belt layers 64, 65, respectively. In the present case, the sealant layer 20 is attached to the inner liner 61 by a metal foil 22, which is attached to the inner liner 61 by an adhesive, preferably after the tire 1 is cured. Therefore, preferably, the sealant layer 20 is also applied after the tire is cured, or in other words, post-cured. The adhesive used to bond the metal foil 22 to the inner liner can, for example, include one or more of cyanoacrylate adhesives, epoxy adhesives, silicone adhesives, and other adhesives known in the art for connecting rubber to metal. In an alternative embodiment, the layer between the sealant and the inner liner includes a metal mesh, which can be at least partially adhered to the inner liner by the adhesiveness of the sealant layer. In yet another embodiment, the layer between the sealant layer and the inner liner can be a conductive rubber layer disposed on the surface of the inner liner. For example, such a layer can be cured together with the tire. In yet another embodiment, the conductive layer arranged between the liner and the sealant layer may be a fabric coated with a metal at least on the radially inner side and co-cured with the liner, for example using a coating such as resorcinol formaldehyde latex (RFL) to improve the adhesion of the fabric to the liner. In another option, two conductive layers of insulated parallel wires may be provided between the liner and the radially outer side of the sealant layer, for example Figure 8 and 9 The conductive layer is shown radially inward of the sealant layer.

[0139] because Figure 1 The sealant layer 20 of the embodiment of the present invention generally comprises a viscous elastomeric compound, so that generally no additional adhesive is required to keep the sealant on the metal foil 22. Still according to the present embodiment, another metal foil 21 is attached to the sealant layer 20 radially inside the sealant layer 20. The two foils 21 and 22 are separated from each other spatially and electrically and / or non-conductively. In order to reduce the possibility of the two foils 21, 22 directly contacting each other, an axial width (not shown in the present embodiment) that is smaller than the axial width of the sealant layer 21, for example at least 1% smaller, can be provided for one or both foils 21, 22 (not shown in the present embodiment). In the present embodiment, the sealant layer 20 is non-conductive.

[0140] Furthermore, the present non-limiting embodiment has a sensor system 30 comprising a sensor transmitter unit 33 and electrically insulating wires 31, 32, which are respectively (electrically and / or conductively) connected to each of the foils 21, 22 and are part of a measuring circuit of the sensor system 30, which is suitable for detecting an increase in the electrical conductivity between the metal foils 21, 22, for example caused by a metal object piercing the tire 1, thereby electrically connecting the two foils 21, 22. Various methods are known in the art for detecting such an increase in electrical conductivity, for example by detecting an increase in the current and / or the current by a current sensor, also as Figure 6 The detected increase in electrical conductivity between the metal foils 21, 22 may then be reported by the transmitter 34 of the sensor transmitter unit 33 to signal a detected tire puncture.

[0141] like Figure 6 As further shown, the first conductive layer, e.g. metal foil 21, is electrically connected to a first pole of a power supply 331 of a sensor transmitter unit 33 via a wire 31. The second conductive layer, e.g. metal foil 22, is electrically connected to a second pole of the power supply 331 of the sensor transmitter unit 33 via a wire 32. Furthermore, the exemplary measurement circuit comprises a current sensor 332 of the sensor transmitter unit 33, which is arranged and adapted to measure (or in other words determine) a current in case of electrical connection between the foils 21 and 22. It should be emphasized that according to Figure 6 The example measurement circuit of constitutes a suitable but non-limiting example of such a circuit. The sensor transmitter unit 33 may have additional components mentioned herein which are not described in detail. Figure 6 is clearly depicted in the figure.

[0142] Thus, if a conductive object, such as a metal object, such as a nail or a screw, punctures the tire 1, the sensor 332 of the measuring circuit detects a short circuit. The sensor system 30 detects the short circuit by means of the transmitter 34 (eg, comprising an antenna) of the sensor-transmitter unit 33. Figure 6 Preferably, the transmitter 34 is integrated in the sensor transmitter unit 33 in a common housing with the sensor 332 and the power supply 331. Figure 1 As shown, the sensor transmitter unit 33 may be attached to the inner surface 60 of the tire 1 at the tire sidewall 50. Also as shown, the sensor transmitter unit 33 may be held by a container 36 that is bonded and / or cured to the inner surface 60 of the tire 1, in particular to the inner liner 61. Such a container 36 may consist of or include a rubber composition, preferably a sulfur-cured rubber composition.

[0143] The rubber composition mentioned herein may include one or more rubbers selected from natural rubber, synthetic polyisoprene, polybutadiene rubber and styrene butadiene rubber. Such rubbers may be functionalized or non-functionalized, for example, for coupling with silica and / or carbon black filler. The rubber composition may also include one or more fillers, such as silica and / or carbon black. They may also include one or more of sulfur curing accelerators, processing aids, oils, resins, zinc oxide, filler coupling agents and sulfur.

[0144] In order to facilitate a better understanding, this paper Figure 1 The radial direction r, the circumferential direction c and the axial direction a are indicated in the tire and other drawings. The axial direction is parallel to the axis of rotation of the tire. The circumferential direction c is parallel to the circumference of the tire and is perpendicular to the axial direction a. The radial direction r is also perpendicular to the axial direction and the circumferential direction c. It should be emphasized that, unless otherwise specified herein, a reference to one of these directions does not necessarily limit it to a certain orientation.

[0145] refer to Figure 2 and 7 The function of the sensor system 30 is further described in Figure 1 and 6 In particular, Figure 2 Shows that already Figure 1 1 , which has been punctured by a screw 70. The screw 70 extends transversely through the tread portion 10, the cover layer 66, the two belt layers 64, 65, the carcass plies 62, 63, the inner liner 61, and through the metal foils 21, 22, as well as through the sealant layer 20. Although the material of the sealant layer 20 seals the puncture to prevent air pressure loss and usually also flows partially along the elongated screw 70, the puncture is detected by the sensor system 30. In particular, the screw 70 is in most cases a metal screw 70, and in this context also a metal screw 70, which connects the metal foil 21 electrically and / or conductively with the metal foil 22. As already mentioned above, each metal foil 21, 22 is connected at a respective axially outer portion with a wire 31, 32 of the sensor system 30. The sensor transmitter unit 33 detects by its sensor the increased current between the foils 21, 22, in this case a short circuit, due to the metal screw 70. Based on this detected short circuit, the sensor system 30 issues an alert to the driver and / or the vehicle about the detected short circuit and thus a possible tire puncture by means of a wireless signal sent by the transmitter 34. Alternatively, it is possible that the sensor system comprises a receiver allowing reception of an external status request, such as a tire puncture status request, which triggers the sending of a wireless signal by the transmitter 34 indicating a detected short circuit and / or an apparent tire puncture. Such a request may be sent by the vehicle or another external device.

[0146] Figure 7Shown with Figure 6 The same measuring circuit, but additionally schematically showing a metal screw 70, which electrically connects the conductive layers or foils 21 and 22. In other words, Figure 7 In the embodiment, the measuring circuit is electrically closed by a metal screw electrically connecting foil 21 to foil 22 (while Figure 6 21 and 22 are disconnected) so that the current sensor 332 detects the current and / or short circuit between the metal foils 21 and 22. Optionally, one or more resistors (not shown here) can be arranged in the circuit to reduce the current between the poles of the power supply 331 when the layers or foils 21, 22 are electrically connected by the screws 70. For example, one or more resistors can be arranged in the wires between the foil 22 and the corresponding poles of the power supply 331. Other suitable resistor arrangements are also possible. However, such additional resistors are not mandatory.

[0147] Figure 3 Another embodiment of the invention is shown, wherein the tire 1' comprises a sensor system 30', which is arranged and / or configured for detecting tire punctures. Figure 1 and 2 The structure of the tire 1 shown in FIG. 1 is similar. Therefore, the tire 1' also includes a tread portion 10', two sidewalls 50' and two bead portions 40', each bead portion including a bead 41', an apex 43' and a bead chafer 42'. In addition, the tire 1' includes an inner liner 61', which forms the inner surface 60' of the tire 1' and partially surrounds the tire cavity. The tire 1' also includes two carcass plies 62', 63' folded around each bead 41', as well as two belt layers 64', 65', and a covering layer 66' covering the belt layers 64', 65'.

[0148] The tire 1' also includes a sealant layer 20', which is directly attached to the inner surface 60' of the inner liner 61' (without adhesive). Preferably, the sealant layer 20' is applied after the tire is cured, in other words, post-cured. In this embodiment, the sealant layer 20' is covered by a metal foil 21', which is connected to the sensor transmitter unit 33' via a wire 31'. In addition, the sensor transmitter unit 33' is connected to the tire inner liner 61' via a second wire 32', which is a conductive inner liner 61' in this case, or in other words consists of or includes a conductive rubber composition. The sensor transmitter unit 33' is attached to the inner liner 61' via a container 36' based on a rubber composition and includes a current sensor and a transmitter 34'. Preferably, it also includes one or more of a power supply, a memory and a receiver (not shown herein). The transmitter 34' and the sensor transmitter unit 33' are configured to wirelessly transmit signals, which can be received by the respective vehicles, such as vehicle computers (not shown), for example.

[0149] exist Figure 4 middle, Figure 3 The tyre 1' has been shown to be punctured by a nail 70', in particular a metal nail 70'. The nail 70' extends through the radially outer surface of the tread portion 10' beyond the radially inner surface of the metal foil 21'. Thereby, the nail 70' electrically connects the conductive inner lining 61' with the metal foil 21'. Each of the inner lining 61' and the foil 21' is electrically connected to a sensor of the sensor transmitter unit 33', so that the sensor transmitter unit 33' detects an increase in the electrical conductivity between the inner lining 61' and the metal foil 21' and generates an alarm signal which is wirelessly transmitted by the transmitter 34'. Thereby, a tyre puncture is reported and the tyre 1' can be checked.

[0150] Figure 5 Another preferred embodiment according to the present invention is shown. Figure 5 The tire 1″ likewise comprises a tread portion 10″, two sidewalls 50″ and two bead portions 40″, each bead portion comprising a bead 41″, a bead apex 43″ and a bead filler 42″. Furthermore, the tire 1″ comprises an inner liner 61″, which forms an inner surface 60″ of the tire 1″ and partially surrounds the tire cavity. The tire 1″ further comprises two carcass plies 62″, 63′ folded around each bead 41″, as well as two belt layers 64″, 65″ and a cover layer 66″ covering the belt layers 64″, 65″. Furthermore, the tire 1″ comprises a conductive rubber composition layer 22″ and a metal foil 21″, which are arranged parallel to the sealant layer 20″. The conductive rubber composition layer may, for example, be a conductive second sealant layer, or a cured rubber composition layer (e.g., which has been cured together with the tire). Alternatively, the conductive rubber composition layer 22″ may be co-cured with the already cured inner liner layer. In another alternative, the metal foil 21 ″ may be replaced by one or more of metal powder coating, metal plasma coating, metal mesh, and a plurality of metal wires.

[0151] Figure 5 The sensor system 30" comprises an RFID tag 33", which can also be regarded as constituting a sensor transmitter unit. The RFID tag 33" comprises a preferably integrated receiver (e.g., a radio frequency receiver), a preferably integrated transmitter (e.g., a radio frequency transmitter), and a preferably integrated sensor (e.g., a current sensor). The RFID tag 33" is electrically connected to the conductive rubber layer 22" and the metal foil 21" separately via wires 32" and 31", respectively. The corresponding measurement circuit can correspond to Figure 6 and Figure 7 The measurement circuit has been shown in Figure 5In the case shown, a conductive metal screw has punctured the tire 1' and electrically connected the conductive rubber layer 22' to the metal foil 21', wherein the inner liner 61' and the sealant layer 20' are non-conductive in this embodiment. When the tire is punctured, the RFID tag 33' sends a signal via its integrated transmitter indicating a short circuit between the conductive rubber layer 22' and the metal foil 21'. The signal can be sent to an (external) RFID receiver (not shown) present in the vehicle on which the tire 1' is mounted. In another option, the vehicle and / or the (external) RFID receiver are configured to send a request to the RFID tag 33', for example, requesting whether a short circuit between the conductive layer 22' and the metal foil 21' is detected. When such a request is received by a receiver (e.g. a radio frequency receiver) of the RFID tag 33' from the vehicle and / or the RFID receiver, the RFID tag 33' replies to the RFID reader via its transmitter.

[0152] Although the sensor transmitter units have been shown herein as being attached to the sidewall portion of the tire, they may also be attached radially inside the sealant layer or to an additional layer radially inside the sealant layer.

[0153] As described above, the sensor system and / or sensor transmitter unit provided herein may include a power source, such as a battery. Alternatively, power may be provided remotely, such as via electromagnetic waves. In this case, receiving such electromagnetic waves by a power receiving device (e.g., an (electric) coil) is also considered a power source.

[0154] Figure 8 Another embodiment of a tire according to the present invention is shown. In this embodiment, the tire 1'" comprises a sealant layer 20'" which is arranged on the inner liner 61'" radially opposite the tread portion 10'"'. In addition, the tire 1'" comprises two conductive layers 21'"' and 22'"', which are connected to a sensor transmitter unit 33'"' of a sensor system 30'"' via electrical wires 31'"' and 32'"', respectively. A sensor system 30'"' like this can operate in the same or similar manner as already disclosed in other embodiments herein. In the present embodiment, both conductive layers 21'", 22'" are attached to the radially inner side or surface of the sealant layer 20'". This may be particularly advantageous from an attachment point of view. Optionally, the two conductive layers 21'", 22'" are connected to each other by an adhesive. In the present embodiment, at least one, preferably each conductive layer 21'", 22'" also includes electrical insulation. In other words, although each layer 21'", 22'" is conductive, it is insulated from another adjacent conductive layer 22'", 21'" by external electrical insulation. More details about the layers 21'", 22'" as viewed from the radial direction r are given in Fig. 9 is shown in a schematic plan view.

[0155] like Fig. 9 As can be seen in the figure, each of the conductive layers 21'', 22'' comprises a plurality of parallel conductors which are electrically connected to the respective electrical wires 31'', 32''. In the present example, each conductor is electrically conductive (as a metal conductor) but comprises an (external) insulating coating (e.g. an insulating varnish, or e.g. a polymer insulating sheath). In the present example, both conductive layers 21'', 22'' can be held in place by the bonding of the sealant layer 20'' ( Fig. 9 not shown).

[0156] In an alternative embodiment, it is possible that the two conductive layers remain parallel to each other but are interwoven, for example, so that the wires of one conductive layer constitute the warp of the woven mesh and the wires of the other conductive layer constitute the weft of the woven mesh. In another option, it is possible that the wires of the first conductive layer and the wires of the second conductive layer are arranged alternately parallel to each other. A piercing object such as a metal nail or screw may damage the insulating coating of adjacent wires, resulting in a short circuit or increased conductivity between the two conductive layers.

[0157] In yet another embodiment, it is possible that two conductive layers are arranged on top of each other but separated by an insulating layer (eg an insulating polymer layer or an insulating coating) provided on the side of one of the conductive layers facing the other adjacent conductive layer.

[0158] In summary, the present invention and its embodiments provide an advanced tire having tire puncture sealing properties and, in particular, further allowing detection of such punctures despite maintenance of tire pressure by the sealing material.

[0159] According to the description provided herein, the present invention can be changed. Although certain representative embodiments and details have been shown to illustrate the present invention, it should be understood by those skilled in the art that various changes and modifications can be made thereto without departing from the scope of the present invention. Therefore, it should be understood that the specific embodiments described can be changed, and these changes will fall within the full expected scope of the present invention defined by the appended claims.

Claims

1. A tire, comprising: Circumferential tread portion; partially surrounding an inner surface of a tire cavity; a circumferential sealant layer disposed at least partially on the inner surface radially below the tread portion, wherein the sealant layer has a radially inner side and a radially outer side; a first conductive layer at least partially covering one side of the sealant layer; a second conductive layer, the second conductive layer being arranged substantially parallel to the first conductive layer and being non-conductively separated from the first conductive layer; and A sensor system is in electrical contact with the first and second conductive layers, respectively, and is adapted to detect an increase in conductivity between the first and second conductive layers.

2. The tire of claim 1, wherein the first conductive layer comprises one or more of a conductive coating, a conductive foil, a conductive mesh, a conductive fabric, a plurality of conductive threads, and a conductive elastomeric composition.

3. The tire of claim 1, wherein at least one of the first conductive layer and the second conductive layer comprises one or more of a metal coating, a metal foil, a metal mesh, a plurality of conductive metal wires, and a conductive rubber composition. The tire according to claim 1 , wherein the first conductive layer has a thickness in the range of 0.1 mm to 1 mm. The tire of claim 1 , wherein the sealant layer has a thickness in the range of 1 mm to 8 mm.

6. The tire of claim 1, wherein the sealant layer comprises an elastomeric composition comprising: From 80 to 100 phr of rubber, which is selected from one or more of butyl rubber, halogenated butyl rubber, EPDM rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylonitrile-butadiene-styrene rubber, polybutadiene rubber, natural rubber, and synthetic polyisoprene; From 20phr to 100phr of filler; and From 150 to 600 phr of a liquid plasticizer selected from one or more of oils, liquid polymers and polyisobutylene.

7. The tire of claim 1, wherein the sealant layer comprises an elastomeric composition comprising: From 80 to 100 phr of a rubber selected from butyl rubber and halogenated butyl rubber; From 20 phr to 90 phr of filler, including one or more of carbon black and silica; and From 300 to 600 phr of a liquid plasticizer selected from one or more of oils, liquid polymers and polyisobutylene.

8. The tire of claim 1, wherein each conductive layer extends over at least 70% of the area of ​​the adjacent surface of the sealant layer.

9. The tire of claim 1, wherein the tire comprises one or more of the following: i) an inner liner forming at least part of the inner surface of the tire, comprising an electrically conductive rubber composition, ii) a belt layer arranged radially between the sealant layer and the tread portion and comprising a conductive rubber composition, iii) a covering layer comprising a conductive rubber composition, iv) a tread base layer comprising a conductive rubber composition, and v) a tread portion comprising a layer of electrically conductive rubber composition extending axially over at least 90% of the axial width of the tire's footprint; and At least one of the conductive rubber compositions forms a second conductive layer.

10. The tire of claim 1, wherein one or more of the first conductive layer and the second conductive layer are electrically insulating.

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