Tyre with asymmetric conductive paths

Abstract

The invention discloses a tire with an asymmetric conductive path. In one aspect, the invention relates to a tire in which a first sidewall and a first chafer adjacent the first sidewall have a volume resistivity of less than 108 ohm * cm. Further, at least one of the second sidewall and a second chafer adjacent to the second sidewall has a volume resistivity higher than 109 ohm * cm. In another aspect, each of the first sidewall and the first chafer comprises at least 39 phr of carbon black, and each of the second sidewall and the second chafer comprises at most 35 phr of carbon black. In yet another aspect, the tire has first and second tread base layers arranged axially alongside one another, where the first tread base layer has a volume resistivity below 108 ohm * cm and the second tread base layer has a volume resistivity above 109 ohm * cm.

Description

Technical Field

[0001] The present invention relates to a tire having tire components having different volume resistivities, in particular on different lateral sides of the tire. Furthermore, the present invention relates to a method for manufacturing such a tire. Background Art

[0002] Tires require a certain electrical conductivity to allow static charge to be conducted from the vehicle to the environment. In particular, this helps prevent static shock (e.g., when contacting a car). This conductivity is usually achieved by a sufficient amount of carbon black in the rubber composition in multiple tire components to provide a conductive path between the rim and the road surface. However, in many cases, the presence of carbon black is detrimental to reducing rolling resistance. It is desirable to provide a tire with reduced rolling resistance while ensuring that the tire has enough conductivity.

[0003] U.S. Patent Application Publication 2005 / 0103412A1 discloses a tire having a rubber sidewall covered with an internal conductive rubber strip. The strip extends from the conductive tread base layer of the tire into the bead area of ​​the tire. While this design can provide an electrical path for some tire types, it is not suitable for other tire types and requires a special construction process. In addition, it is desirable to provide a further improved conductive path through the tire. Summary of the invention

[0004] In a first aspect of the invention, the invention relates to a tire comprising a tread, a pair of bead portions, a pair of sidewalls, wherein each sidewall extends from the tread to a corresponding bead portion, a pair of chafers, at least one carcass ply, and one or more belt layers radially arranged between the tread and the at least one carcass ply in a crown region of the tire. A first sidewall of the pair of sidewalls has a radial relationship of less than 10° with a first chafer of the pair of chafers adjacent to the first sidewall. 8 ohm·cm. In addition, at least one of i) the second sidewall of the pair of sidewalls and ii) the second chafer of the pair of chafers adjacent to the second sidewall has a volume resistivity higher than 10 9 Volume resistivity of ohm·cm.

[0005] In a second aspect, the invention relates to a tire comprising a tread, a pair of bead portions, a pair of sidewalls, wherein each sidewall extends from the tread to a respective bead portion, an optional pair of chafers, at least one carcass ply, and one or more belt layers radially arranged between the tread and the at least one carcass ply in a crown region of the tire. The tread comprises a first tread base layer and a second tread base layer, wherein the first tread base layer has a thickness of less than 10 mm. 8 ohm·cm, and wherein the second tread base layer has a volume resistivity greater than 10 9In addition, the first tread base layer is axially arranged next to the second tread base layer.

[0006] In a third aspect, the present invention is directed to a tire comprising a tread, a pair of bead portions, a pair of sidewalls, wherein each sidewall extends from the tread to a respective bead portion, a pair of chafers, at least one carcass ply, and one or more belt layers radially disposed between the tread and the at least one carcass ply in a crown region of the tire. In addition, each of a first sidewall of the pair of sidewalls and a first chafer of the pair of chafers adjacent to the first sidewall comprises one or more rubber compositions comprising at least 39 phr of carbon black. Still in accordance with the third aspect, at least one of i) a second sidewall of the pair of sidewalls and ii) a second chafer of the pair of chafers adjacent to the second sidewall comprises one or more other rubber compositions comprising at most 35 phr of carbon black.

[0007] The present invention discloses the following embodiments:

[0008] 1. A tire comprising a tread, a pair of bead portions, a pair of sidewalls, wherein each sidewall extends from the tread to a respective bead portion, a pair of chafers, at least one carcass ply, and one or more belt layers radially arranged between the tread and the at least one carcass ply in a crown region of the tire,

[0009] wherein a first sidewall of the pair of sidewalls and a first chafer of the pair of chafers adjacent to the first sidewall have a thickness less than 10 8 ohm·cm volume resistivity. And

[0010] wherein at least one of i) a second sidewall of the pair of sidewalls and ii) a second chafer of the pair of chafers adjacent to the second sidewall has a thickness greater than 10 9 Volume resistivity of ohm·cm.

[0011] 2. The tire according to embodiment 1, wherein the second sidewall has a thickness higher than 10 9 Volume resistivity of ohm·cm.

[0012] 3. The tire according to embodiment 1, wherein the second bead filler has a thickness greater than 10 mm with respect to the second sidewall. 9 Volume resistivity of ohm·cm.

[0013] 4. The tire according to embodiment 1, wherein the tread comprises a 8 The tread base has a volume resistivity of 0.1 ohm·cm and is in contact with the first sidewall.

[0014] 5. The tire according to embodiment 4, wherein the tread base further comprises a skirt portion at an axially outer side thereof, which is closest to the first sidewall, wherein the skirt portion has a thickness of less than 10 8 Volume resistivity of ohm·cm.

[0015] 6. The tire according to embodiment 1, wherein the tread further comprises a tread strip having a thickness of less than 10 8 The volume resistivity is ohm·cm and extends laterally through the tread from a radially outer surface of the tread to a radially inner position of the tread.

[0016] 7. The tire of embodiment 6, wherein the tread further comprises at least one tread cap layer and one or more tread base layers, wherein the tread strip extends through at least one tread cap layer to contact at least one of the tread base layers.

[0017] 8. The tire of embodiment 7, wherein the tire has a first tread base layer and a second tread base layer,

[0018] The first tread base layer has a thickness less than 10 8 Volume resistivity in ohm cm,

[0019] The second tread base layer has a thickness greater than 10 9 Volume resistivity of ohm cm; and

[0020] Wherein the tread strip contacts at least a first tread base layer.

[0021] 9. The tire of embodiment 8, wherein the first tread base layer extends over at most 40% of the total axial width of the tread, and wherein the second tread base layer extends over at least 60% of the total axial width of the tread.

[0022] 10. The tire of embodiment 8, wherein the first tread base layer and the second tread base layer are arranged axially alongside each other, and wherein the first tread base layer is disposed axially closer to the first sidewall than the second tread base layer.

[0023] 11. Tire according to embodiment 6, wherein said tread strip has a maximum width, measured in the axial direction of the tire, comprised between 0.2 mm and 9 mm.

[0024] 12. The tire according to embodiment 7, wherein, in addition to the tread strip, at least one tread cap layer has a thickness greater than 10 9 Volume resistivity of ohm·cm.

[0025] 13. The tire of embodiment 7, wherein the tread comprises:

[0026] The first tread cap layer intended to contact the road;

[0027] a second tread cap layer disposed radially below the first tread cap layer;

[0028] a first tread base layer disposed radially below the second tread cap layer;

[0029] A second tread base layer is disposed radially below the second tread cap layer and axially beside the first tread base layer.

[0030] 14. The tire of embodiment 13, wherein the first tread base layer extends over less than 30% of the total axial width of the first tread cap layer and contacts the tread strip at its radially inner end, and wherein the first tread base layer is disposed on the same lateral side of the tire as the first sidewall.

[0031] 15. The tire of embodiment 8, wherein one or more of the tread strip, the first sidewall, the first chafer, and the first tread base layer comprises one or more of the following: a) having a thickness of less than 10 7 ohm·cm; b) a rubber composition comprising more than 50 phr of carbon black; and c) a rubber composition comprising carbon black having an iodine absorption of at least 100 g / kg.

[0032] 16. The tire of embodiment 8, wherein one or more of i) the at least one tread cap layer, ii) the second tread base layer, iii) the second sidewall, iv) the second chafer, v) the one or more belt layers, vi) the at least one carcass ply, and vii) the covering layers of the tire comprises one or more of the following: a) having a thickness greater than 10 9 ohm·cm; b) a rubber composition comprising less than 45 phr of carbon black; and c) a rubber composition comprising carbon black having an iodine absorption of less than 90 g / kg.

[0033] 17. The tire of embodiment 1, wherein each chafer contacts the radially inner end of the corresponding sidewall and extends to a portion of the corresponding bead portion radially below the bead.

[0034] 18. The tire according to embodiment 1, wherein the first sidewall comprises a rubber composition having a tan δ value higher than 0.1 and the second sidewall comprises a rubber composition having a tan δ value lower than 0.09.

[0035] 19. A tire comprising a tread, a pair of bead portions, a pair of sidewalls, wherein each sidewall extends from the tread to a respective bead portion, at least one carcass ply, and one or more belt layers radially disposed between the tread and the at least one carcass ply in a crown region of the tire,

[0036] The tread comprises a first tread base layer and a second tread base layer,

[0037] The first tread base layer has a thickness less than 10 8 ohm·cm volume resistivity and wherein the second tread base layer has a volume resistivity higher than 10 9 ohm cm volume resistivity; and

[0038] The first tread base layer is axially arranged beside the second tread base layer.

[0039] 20. A tire comprising a tread, a pair of bead portions, a pair of sidewalls, wherein each sidewall extends from the tread to a respective bead portion, a pair of chafers, at least one carcass ply, and one or more belt layers radially disposed between the tread and the at least one carcass ply in a crown region of the tire,

[0040] wherein each of a first sidewall of the pair of sidewalls and a first chafer of the pair of chafers adjacent to the first sidewall comprises one or more rubber compositions comprising at least 39 phr of carbon black, and

[0041] wherein at least one of i) a second sidewall of the pair of sidewalls and ii) a second chafer of the pair of chafers adjacent to the second sidewall comprises one or more rubber compositions comprising up to 35 phr of carbon black. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention will be described by way of example and with reference to the accompanying drawings, in which:

[0043] Figure 1 is a cross-sectional view of a tire according to an embodiment of the present invention;

[0044] Figure 2 yes Figure 1 an enlarged cross-sectional view of a first lateral side of the tire shown in FIG. 1 ; and

[0045] Figure 3 yes Figure 1 An enlarged cross-sectional view of a second lateral side of the tire is shown in FIG. DETAILED DESCRIPTION

[0046] According to a first aspect of the invention, a tire comprises a tread, a pair of bead portions, a pair of sidewalls, wherein each sidewall extends from the tread to a respective bead portion, a pair of chafers, at least one carcass ply, and one or more belt layers radially arranged between the tread and the at least one carcass ply in a crown region of the tire. A first sidewall (or in other words a sidewall assembly) of the pair of sidewalls (or in other words a plurality of sidewall assemblies) and a first chafer of the pair of chafers adjacent to the first sidewall have a radial distance of less than 10 mm. 8 ohm·cm, and at least one of i) a second sidewall (or sidewall component) of the pair of sidewalls and ii) a second chafer of the pair of chafers adjacent to the second sidewall has a volume resistivity greater than 10 9 In other words, each of the first sidewall and the first chafer has a volume resistivity of less than 10 8 ohm·cm, and at least one of the second sidewall and the second chafer (preferably both) has a volume resistivity higher than 10 9 Volume resistivity of ohm·cm.

[0047] Thus, the two sides of the tire (transversely opposite) have different electrical conductivities. For example, a sidewall having a lower rolling resistance than the first sidewall can be used as the second sidewall, in particular in cases where it is sufficient for the tire to have one conductive side. In other words, the rubber composition of the first sidewall (or sidewall assembly) and the chafer has a lower volume resistivity than the different rubber composition of the second sidewall (or sidewall assembly) and / or the second chafer.

[0048] Volume resistivity is measured herein according to ASTM D257-98 or an equivalent method.

[0049] In one embodiment, the second sidewall has a thickness greater than 10 9 Volume resistivity of ohm·cm.

[0050] In another embodiment, each of the second chafer and the second sidewall has a thickness greater than 10 9 Volume resistivity in ohm·cm. A chafer may be further described as a portion of a tire that at least partially surrounds a corresponding bead.

[0051] In another embodiment, the tread comprises a 8 ohm·cm, and which is preferably in contact with said first sidewall, optionally via a skirt portion. Optionally, such a tread base or tread base is the only tread base or tread base of the tire or tread. Optionally, it extends at least over the maximum axial width of the axially widest belt ply of the tire.

[0052] In yet another embodiment, the tread base or tread sublayer further comprises a skirt portion at an axially outer side thereof, which is closest to the first sidewall and which has a thickness of less than 10 8 ohm·cm volume resistivity. Optionally, the skirt portion is formed integrally with the rubber composition of the tread base or tread base layer. The skirt portion may also be referred to as a wing portion. The skirt or wing portion preferably has an axial width that tapers in a radially outward and / or axially inward direction. In addition or alternatively, it is at least partially arranged between the (adjacent and / or first) sidewall and the axially outer end portion of one or more tread layers (in particular the tread cap layer). In particular, the skirt portion may be considered herein as part of the tread base or tread base layer.

[0053] In another embodiment, the tread further comprises a 8 A tread strip having a volume resistivity of 100 ohm·cm, extending from a radially outer surface (preferably transversely) of the tread to a radially inner position of the tread. In particular, such a strip can provide electrical conduction through the non-conductive tread, in particular through the non-conductive tread cap layer.

[0054] In another embodiment, the tread further comprises at least one tread cap layer and one or more tread base layers, wherein the tread strip extends through at least one tread cap layer to contact at least one of the tread base layers. In particular, it is possible that the tread base layer contacted by the tread strip is electrically conductive and / or has a conductivity of less than 10 8 Preferably, the tread base layer is in conductive contact with the first sidewall, such as direct contact or via contact through the conductive skirt portion.

[0055] In another embodiment, the tire has a first tread base layer and a second tread base layer, wherein the first tread base layer has less than 10 8 ohm·cm, and / or wherein the second tread base layer has a volume resistivity higher than 10 9 In particular, the tread strip preferably (physically) contacts at least the first tread base layer. Preferably, the first tread base layer is in conductive contact with the first sidewall, such as directly or via a conductive skirt portion.

[0056] In yet another embodiment, the first tread base layer extends over at most 40% (preferably at most 30%, or more preferably at most 20%) of the (maximum) total axial width of the tread / radially outermost tread crown layer, and wherein the second tread base layer extends over at least 60% (preferably at least 70%, or more preferably at least 80%) of the (maximum) total axial width of the tread / radially outermost tread crown layer.

[0057] In yet another embodiment, the first tread base layer extends over at least 10% of the (maximum) total axial width of the tread / radially outermost tread crown layer, and / or the second tread base layer extends over at most 90% of the (maximum) total axial width of the tread / radially outermost tread crown layer.

[0058] In yet another embodiment, the first tread base layer and the second tread base layer are arranged axially or transversely side by side with each other, wherein the first tread base layer is arranged axially closer to the first sidewall than the second tread base layer. In other words, the first tread base layer is arranged only on one axial or transverse side (or in other words half) of the tire, while the second tread base layer preferably extends on both sides (or both halves) of the tire.

[0059] In yet another embodiment, the tire further comprises a tire having less than 10 8 A rubber strip having a volume resistivity of 100 ohm·cm is provided, the rubber strip extending from the radially inner side of the tread to the radially outer side of the first sidewall so as to electrically contact the radially inner side of the tread with a radially outer position of the first sidewall. Such a rubber strip can, for example, electrically connect a tread having one or more non-conductive tread caps and / or base layers with the sidewall. Preferably, it contacts the tread strip as described in various embodiments herein.

[0060] In yet another embodiment, the rubber strip extends perpendicularly or substantially perpendicularly to the circumferential direction of the tire. In other words, preferably, the length of the strip does not extend in the circumferential direction of the tire.

[0061] In yet another embodiment, the rubber strip has one or more of the following:

[0062] a width measured perpendicular to its length in the range of 5 mm to 100 mm, preferably 10 mm to 80 mm, or more preferably 15 mm to 70 mm;

[0063] a thickness measured perpendicular to its length in the range of 0.2 mm to 3 mm, preferably 0.2 mm to 2 mm, or to only 1 mm;

[0064] A substantially flat and / or rectangular cross-section perpendicular to its length; and

[0065] A rectangular cross-section perpendicular to its length having an aspect ratio of thickness to width in the range of 1:5 to 1:100, or preferably 1:10 to 1:80.

[0066] In yet another embodiment, the rubber strip is disposed within the tire. Thus, the strip is not visible on the outside of the tire and / or is protected by the sidewall of the tire from damage and weather conditions such as UV light.

[0067] In another embodiment, the tread band extends transversely to the axial direction, for example substantially in the radial direction or through the tread in the radial direction. Optionally, the tread band also extends circumferentially through the tread, for example over the entire circumference of the tread. Optionally, the tread band electrically connects the radially outer surface of the tread (intended to contact the road) with the radially inner surface or bottom of the tread and / or with the tread base layer. In other words, it provides an electrically conductive path from the outer surface of the tread to the radially inner bottom (surface) of the tread. Preferably, transverse to the axial direction in this document means extending in a direction perpendicular to the axial direction, i.e. in the radial direction and / or extending in a direction at an angle to the radial direction, such as less than 20°, preferably less than 10°, less than 5°, or even less than 2°.

[0068] In another embodiment, the tread strip extends straight or substantially straight across the tread.

[0069] In yet another embodiment, the tread strip has a maximum width measured in the axial direction of the tire ranging from 0.2 mm to 9 mm.

[0070] In yet another embodiment, at least one tread cap layer, in addition to the tread strip, has a thickness greater than 10 9 Volume resistivity of ohm·cm.

[0071] In yet another embodiment, the tread (optionally each of its tread layers) has, in addition to the tread strip, a thickness greater than 10 9 ohm·cm, or higher than 10 10 ohm·cm, preferably higher than 10 11 ohm·cm, or higher than 10 12 ohm·cm. Optionally, the volume resistivity is at most 10 14 If the tread comprises a plurality of tread rubber compositions, it is preferred that each of these tread rubber compositions has a volume resistivity within one of the above ranges.

[0072] In yet another embodiment, the tread, or alternatively the tread cap and / or the tread base, has a thickness of less than 10 8 Volume resistivity of ohm·cm.

[0073] In yet another embodiment, the tread includes a vertically split tread cap having at least one tread cap shoulder portion, wherein the tread cap shoulder portion (and / or the rubber composition of the tread cap shoulder portion) has a relative humidity of less than 10%. 8 Volume resistivity of ohm·cm.

[0074] In yet another embodiment, the tread comprises a first tread cap layer (intended to contact the road); a second tread cap layer, which is radially disposed below the first tread cap layer; a first tread base layer, which is radially disposed below the second tread cap layer; and a second tread base layer, which is radially disposed below the second tread cap layer and axially disposed beside the first tread base layer. Preferably, one or more of the layers extend primarily in the axial direction (and / or circumferentially around the tire).

[0075] In yet another embodiment, the first tread base layer extends over less than 30% (and preferably more than 5%) of the total axial width of the first tread cap layer and is in (physical) contact with the tread strip at its radially inner end. Preferably, the first tread base layer is provided on the same lateral side or half of the tire as the first sidewall.

[0076] In yet another embodiment, one or more of the tread, tread layer, sidewall, chafer, skirt, tread strip, bead, apex, bead portion, belt layer and carcass ply may be considered to extend circumferentially through and / or around (the entire) tire.

[0077] In yet another embodiment, one or more of the tread strip, the first sidewall, the first chafer, and the first tread base layer comprises one or more of the following: a) having a thickness of less than 10 7 ohm·cm, preferably less than 0.5×10 7 ohm·cm; b) a rubber composition comprising at least or more than 39 phr of carbon black, preferably more than 40 phr of carbon black, or more than 50 phr of carbon black; and c) a rubber composition comprising carbon black having an iodine absorption of at least 100 g / kg, preferably 100 g / kg to 300 g / kg, even more preferably 100 g / kg to 250 g / kg, or 110 g / kg to 200 g / kg. In other words, one or more of the components each comprise or consist of a rubber composition having the volume resistivity. The tread strip may comprise or consist of a tread strip rubber composition; the first sidewall may comprise or consist of a first sidewall rubber composition; the first bead cover may comprise or consist of a first bead cover rubber composition, and the first tread base layer may comprise or consist of a first tread base layer rubber composition. It is noted that rubber compositions having the desired volume resistivity are known to those skilled in the art. Similarly, the rubber compositions for the second sidewall, second chafer, tread cap layer, tread base layer are also known to those skilled in the art, while the combination and / or arrangement of those are not known.

[0078] Iodine absorption or iodine absorption value (sometimes also referred to as iodine value or iodine absorption value) is measured herein according to ASTM D1510 or an equivalent method.

[0079] In yet another embodiment, one or more of i) at least one tread cap layer, ii) a second tread base layer, iii) a second sidewall, iv) a second chafer, v) one or more belt layers, vi) at least one carcass ply, and vii) the covering layers of the tire comprises one or more of the following: a) having a thickness greater than 10 9 ohm·cm, preferably higher than 10 10 ohm·cm or even higher than 10 12 ohm·cm; b) a rubber composition comprising less than 45 phr of carbon black, preferably less than 40 phr of carbon black, more preferably less than 35 phr of carbon black, or less than 20 phr of carbon black, or even less than 10 phr of carbon black; and c) a rubber composition comprising carbon black having an iodine absorption of less than 90 g / kg, preferably less than 80 g / kg, or less than 50 g / kg.

[0080] In other words, each of these components may contain or consist of a rubber composition having such a volume resistivity and / or carbon black content. In particular, the tread cap layer may contain or consist of a tread cap layer rubber composition, the second tread base layer may contain or consist of a second tread base layer rubber composition, the second sidewall may contain or consist of a second sidewall rubber composition, the second bead cover may contain or consist of a second bead cover rubber composition, at least one carcass ply may contain a carcass ply (coating) rubber composition, and one or more belt layers may contain a belt ply (coating) rubber composition. Each of these rubber compositions is preferably within the required resistivity range and / or has the mentioned amount of carbon black. In one or more of the above compositions, the minimum amount of carbon black is preferably 0.1 phr. However, it can also be zero, especially in components that are not visible on the tire surface.

[0081] In yet another embodiment, each chafer contacts the radially inner end of the respective sidewall and extends to a portion radially below the bead of the respective bead portion.

[0082] In yet another embodiment, the first sidewall and / or the first chafer comprises a rubber composition having a tan delta value higher than 0.09, preferably higher than 0.1. Alternatively or in addition, the second sidewall and / or the second chafer comprises a rubber composition having a tan delta value lower than 0.09, preferably lower than 0.08.

[0083] According to a second aspect, a tire comprises a tread, a pair of bead portions, a pair of sidewalls, wherein each sidewall extends from the tread to a respective bead portion, an optional pair of chafers, at least one carcass ply, and one or more belt layers radially arranged between the tread and the at least one carcass ply in a crown region of the tire. The tread comprises a first tread base layer and a second tread base layer, wherein the first tread base layer has a thickness of less than 10 mm. 8 ohm·cm, and wherein the second tread base layer has a volume resistivity greater than 10 9 The first tread base layer is axially arranged next to the second tread base layer.

[0084] Thus, while the first tread base layer (axially adjacent to the second tread base layer) can be considered to be conductive, the second tread base layer is not conductive. By providing a conductive first tread base layer, an electrical path can be provided on at least one lateral / axial side of the tire. In particular, a second tread base layer can be provided that has lower hysteresis and / or rolling resistance than the first tread base layer.

[0085] In one embodiment, the first tread base layer extends over at most 40% of the total axial width of the tread, and / or the second tread base layer extends over at least 60% of the total axial width of the tread. Thus, the first tread base layer has a relatively small extension and / or amount of rubber composition compared to the second tread base layer.

[0086] In another embodiment, the first sidewall of the pair of sidewalls and preferably the first chafer of the pair of chafers adjacent to the first sidewall (each) have a thickness of less than 10 8 ohm·cm volume resistivity. Preferably, the first sidewall contacts the first tread base layer. Optionally, the second sidewall of the pair of sidewalls and at least one of the second chafers of the pair of chafers adjacent to the second sidewall have a resistivity higher than 10 9 Alternatively, at least one of the second sidewall of the pair of sidewalls and the second chafer adjacent to the second sidewall of the pair of chafers has a volume resistivity of less than 10 8 Volume resistivity of ohm·cm.

[0087] In another embodiment, the first sidewall and the second sidewall comprise or consist of the same rubber composition; and / or the first chafer and the second chafer comprise or consist of the same rubber composition.

[0088] Preferably, the chafer herein contacts and is adjacent to the sidewall.

[0089] In yet another embodiment, the first tread base comprises a rubber composition having a tan delta value higher than 0.09, preferably higher than 0.1. Alternatively or in addition, the second tread base comprises a rubber composition having a tan delta value lower than 0.09, preferably lower than 0.08.

[0090] According to a third aspect, a tire comprises a tread, a pair of bead portions, a pair of sidewalls, wherein each sidewall extends from the tread to a respective bead portion, a pair of chafers, at least one carcass ply, and one or more belt layers radially arranged between the tread and the at least one carcass ply in a crown region of the tire. In addition, each of a first sidewall of the pair of sidewalls and a first chafer of the pair of chafers adjacent to the first sidewall comprises (or consists of) one or more rubber compositions containing at least 39 phr of carbon black (or more than 40 phr or 50 phr of carbon black). Still according to the third aspect, at least one (preferably at least two) of i) a second sidewall of the pair of sidewalls and ii) a second chafer of the pair of chafers adjacent to the second sidewall comprises (or consists of) one or more other rubber compositions containing at most 35 phr of carbon black (preferably at most 20 phr, at most 10 phr, or at most 5 phr of carbon black).

[0091] It is emphasized that each aspect of the present invention can be combined with one or more embodiments or features mentioned in relation to another aspect of the present invention. Only for the sake of brevity, these are not literally repeated here.

[0092] In a preferred embodiment, the tire according to one aspect is selected from one or more of a radial tire, a pneumatic tire, and a passenger car tire.

[0093] In another embodiment, the rubber composition may include at least one or more and / or one or more additional diene-based rubbers, such as one or more of styrene butadiene rubber (SBR, e.g., S-SBR or E-SBR), natural rubber (NR), synthetic polyisoprene (PI), and polybutadiene rubber (BR).

[0094] In one embodiment, synthetic or natural polyisoprene rubber may be used. Synthetic cis-1,4-polyisoprene and natural rubber are known per se to those skilled in the rubber art. In particular, the cis-1,4-microstructure content may be at least 90%, and typically at least 95% or even higher.

[0095] In one embodiment, cis-1,4-polybutadiene rubber (BR) is used. Suitable polybutadiene rubbers can be prepared, for example, by organic solution polymerization of 1,3-butadiene. BR can be conveniently characterized, for example, by having a cis-1,4-microstructure content of at least 90% ("high cis" content) and a glass transition temperature (Tg) of -95°C to -110°C. Suitable polybutadiene rubbers are commercially available, such as from The Goodyear Tire & Rubber Company. 1207, 1208, 1223 or 1280. These high cis-1,4-polybutadiene rubbers can be synthesized, for example, using a nickel catalyst system comprising a mixture of (1) an organonickel compound, (2) an organoaluminum compound, and (3) a fluorine-containing compound, as described in U.S. Pat. No. 5,698,643 and U.S. Pat. No. 5,451,646, which are incorporated herein by reference.

[0096] The glass transition temperature or Tg of an elastomer refers to the glass transition temperature of the corresponding elastomer in its uncured state. The glass transition temperature of an elastomeric composition refers to the glass transition temperature of the elastomeric composition in its cured state. Tg is determined as the peak midpoint by differential scanning calorimetry (DSC) according to ASTM D3418 or an equivalent method at a heating rate of 20°C per minute.

[0097] As used herein and in accordance with conventional practice, the term "phr" means "parts by weight of the respective material per 100 parts by weight of rubber or elastomer". Typically, using this convention, a rubber composition contains 100 parts by weight of rubber / elastomer. The claimed composition may contain other rubbers / elastomers in addition to those explicitly mentioned in the claims, provided that the phr value of the claimed rubber / elastomer conforms to the claimed phr range and the amount of all rubbers / elastomers in the composition yields a total of 100 parts of rubber. Unless otherwise stated, the terms "rubber" and "composition" and "formulation" are used interchangeably herein. The terms "rubber" and "elastomer" are also used interchangeably herein.

[0098] In another embodiment, the rubber composition comprises 1 to 80 phr, or 5 to 80 phr of a resin, preferably having a glass transition temperature Tg greater than 20°C. The Tg of the resin is determined as the peak midpoint by differential scanning calorimetry (DSC) at a heating rate of 10°C / minute according to ASTM D6604 or an equivalent method. Preferably, the resin has a softening point measured by ASTM E28 above 70°C, which may sometimes be referred to as the ring and ball softening point. In one embodiment, the rubber composition comprises 10 to 60 phr, or 20 to 60 phr, or 30 to 60 phr of a resin, particularly if the rubber composition is a tread cap rubber composition.

[0099] In another embodiment, the resin is selected from coumarone-indene resins, petroleum hydrocarbon resins, terpene polymers / resins, styrene / alpha methyl styrene resins, terpene phenol resins, rosin derived resins, and copolymers and / or mixtures thereof.

[0100] The coumarone-indene resin preferably contains coumarone and indene as monomer components constituting the resin skeleton (main chain). Examples of monomer components other than coumarone and indene that may be introduced into the skeleton are methylcoumarone, styrene, α-methylstyrene, methylindene, vinyltoluene, dicyclopentadiene, cyclopentadiene, and dienes such as isoprene and piperlyene. The coumarone-indene resin preferably has a softening point (measured by the ring and ball method) of 10° C. to 160° C. Even more preferably, the softening point is 30° C. to 100° C.

[0101] Suitable petroleum resins include both aromatic and non-aromatic types. Several types of petroleum resins are available. Some resins have low unsaturation and high aromatic content, while some are highly unsaturated, and others do not contain aromatic structures at all. The difference in resins is mainly due to the olefins in the raw materials from which the resins are derived. Conventional derivatives in such resins include any C5 species (olefins and dienes containing an average of five carbon atoms) such as cyclopentadiene, dicyclopentadiene, dienes such as isoprene and piperylene, and any C9 species (olefins and dienes containing an average of 9 carbon atoms) such as vinyl toluene, α-methyl styrene and indene. Such resins are made from any mixture of the above-mentioned C5 and C9 species and are referred to as C5 / C9 copolymer resins. Petroleum resins with a softening point of 10°C to 120°C are generally available. Preferably, the softening point is 30 to 100°C.

[0102] In one embodiment, the C5 resin is an aliphatic resin made from one or more of the following monomers: 1,3-pentadiene (eg, cis or trans), 2-methyl-2-butene, cyclopentene, cyclopentadiene, and dicyclopentadiene.

[0103] In another embodiment, the C9 resin is a resin made from one or more aromatic monomers, preferably selected from indene, methylindene, vinyltoluene, styrene and methylstyrene (eg, alpha-methylstyrene).

[0104] In yet another embodiment, the C9 modified resin is a resin (such as a C5 resin) that has been modified or functionalized with one or more aromatic monomers, preferably selected from indene, methylindene, vinyltoluene, styrene and methylstyrene (such as α-methylstyrene).

[0105] The terpene resin preferably comprises a polymer of at least one of limonene, α-pinene, β-pinene and δ-3-carene. Such resins are available with a softening point of 10°C to 135°C.

[0106] Terpene-phenol resins can be obtained by copolymerization of phenol monomers with terpenes such as limonene, pinene and delta-3-carene.

[0107] Representative of resins derived from rosin and its derivatives are, for example, gum rosin, wood rosin and tall oil rosin. Gum rosin, wood rosin and tall oil rosin have similar compositions, although the amounts of the components of the rosin may differ. Such resins may be dimerized, polymerized or disproportionated. Such resins may be in the form of esters of rosin acid and polyols such as pentaerythritol or diols.

[0108] Styrene / alpha methylstyrene resins are considered herein to be (preferably relatively short chain) copolymers of styrene and alpha methylstyrene having a styrene / alpha methylstyrene molar ratio in the range of about 0.05 to about 1.50. In one aspect, such resins can be suitably prepared, for example, by cationic copolymerization of styrene and alpha methylstyrene in a hydrocarbon solvent. Thus, the contemplated styrene / alpha methylstyrene resins can be characterized, for example, by their chemical structure, i.e., their styrene and alpha methylstyrene content, and by their glass transition temperature, molecular weight, and molecular weight distribution.

[0109] In one embodiment, the resin is partially or fully hydrogenated.

[0110] In one embodiment, the rubber composition includes oil, such as processing oil. Oil can be included in the rubber composition as a filler oil commonly used to fill elastomers. Oil can also be included in the rubber composition by directly adding the oil during the rubber compounding process. The oil used can include both the filler oil present in the elastomer and the process oil (process oil) added during the compounding process. Suitable oil can include various oils known in the art, including aromatic oils, paraffinic oils, naphthenic oils, vegetable oils and low PCA oils, such as MES, TDAE, SRAE and heavy naphthenic oils. Suitable low PCA oils can include those with a polycyclic aromatic hydrocarbon content of less than 3 weight % as measured by the IP346 method. The procedure of the IP346 method can be found in Standard Methods for Analysis & Testing of Petroleum and Related Products and British Standard 2000 Parts, 2003, the 62nd edition, the Institute of Petroleum, United Kingdom publishes. Some representative examples of usable vegetable oils include soybean oil, sunflower oil, canola oil (rapeseed oil), corn oil, coconut oil, cottonseed oil, olive oil, palm oil, peanut oil and safflower oil. Soybean oil and corn oil are generally preferred vegetable oils. If used, the rubber composition may also include up to 40phr of processing oil, preferably between 1phr and 25phr. Alternatively, less than 10phr of oil, preferably less than 5phr. The glass transition temperature Tg of the oil is measured in the form of a peak midpoint at a heating rate of 10°C / minute by a differential scanning calorimeter (DSC) according to ASTM E1356 or an equivalent method.

[0111] In one embodiment, the rubber composition comprises silica, particularly if it is a tread rubber composition. The silica may be, for example, pyrolytic / fumed silica or precipitated silica. In a preferred embodiment, precipitated silica is used. The silica may be characterized, for example, by having a BET surface area measured using nitrogen. In one embodiment, the BET surface area may be 40 to 600 square meters per gram. In another embodiment, the BET surface area may be 50 to 300 square meters per gram. The BET surface area is determined according to ASTM D6556 or an equivalent method and is described in Journal of the American Chemical Society, Vol. 60, p. 304 (1930). The silica may also be characterized by having a 100 cm 3 / 100g to 400cm 3 / 100g, or 150cm 3 / 100g to 300cm3 The silica can be characterized by the dibutyl phthalate (DBP) absorption value of 1 / 100 g, which is determined according to ASTM D 2414 or an equivalent method. The silica can have an average final particle size of 0.01 to 0.05 microns, for example, as determined by electron microscopy, although the size of the silica particles may be even smaller or may be larger. The range of use of silica in this article can be, for example, 1 to 120 phr, preferably 10 phr to 70 phr. Various commercially available silicas can be used, for example, by way of example only and not limitation, silicas commercially available from PPG Industries under the Hi-Sil trademark with reference numbers 210, 315G, EZ160G, etc.; silicas available from Solvay, with reference numbers Z1165MP and Premium 200MP, etc.; and silicas available from Evonik AG with reference numbers VN2 and Ultrasil 6000GR, 9100GR, etc.

[0112] Some non-limiting examples of pre-treated silicas (i.e., silicas that have been pre-surface treated with silanes) that may be used in the practice of the present invention include, but are not limited to, silicas that have been pre-treated with mercaptosilanes. 255LD and LP (PPG Industries) silica, and as an organosilane bis (triethoxysilylpropyl) polysulfide (Si69) with The product of the reaction between VN3 and silica 8113 (Degussa), and 6508, from PPG Industries 400 Silica, from PPG Industries 454 Silica and from PPG Industries 458Silicon dioxide.

[0113] In one embodiment, the rubber composition may include carbon black. Representative examples of such carbon black include, for example, N110, N121, N134, N220, N231, N234, N242, N293, N299, N315, N326, N330, N332, N339, N343, N347, N351, N358, N375, N539, N550, N582, N630, N642, N650, N683, N754, N762, N765, N774, N787, N907, N908, N990, and N991 grades.

[0114] In one embodiment, the rubber composition may contain a sulfur-containing organosilicon compound or silane. Examples of suitable sulfur-containing organosilicon compounds have the following formula:

[0115] Z-Alk-S n -Alk-Z I

[0116] Where Z is selected from:

[0117]

[0118] Where R 1 is an alkyl group of 1 to 4 carbon atoms, a cyclohexyl group or a phenyl group; R 2 is an alkoxy group of 1 to 8 carbon atoms or a cycloalkoxy group of 5 to 8 carbon atoms; Alk is a divalent hydrocarbon of 1 to 18 carbon atoms, and n is an integer of 2 to 8. In one embodiment, the sulfur-containing organosilicon compound is 3,3'-bis(trimethoxy or triethoxysilylpropyl)polysulfide. In one embodiment, the sulfur-containing organosilicon compound is 3,3'-bis(triethoxysilylpropyl)disulfide and / or 3,3'-bis(triethoxysilylpropyl)tetrasulfide. Therefore, for Formula I, Z can be

[0119]

[0120] Where R 2 is an alkoxy group of 2 to 4 carbon atoms, or 2 carbon atoms; Alk is a divalent hydrocarbon of 2 to 4 carbon atoms, or 3 carbon atoms; and n is an integer of 2 to 5, or 2 or 4. In another embodiment, suitable sulfur-containing organosilicon compounds include compounds disclosed in U.S. Pat. No. 6,608,125. In one embodiment, the sulfur-containing organosilicon compound includes 3-(octanoylthio)-1-propyltriethoxysilane CH 3 (CH 2 ) 6 C(=O)-S-CH 2 CH 2 CH 2 Si(OCH 2 CH 3 ) 3 , which can be used as NXT TMAvailable from Momentive Performance Materials. In another embodiment, suitable sulfur-containing organosilicon compounds include those disclosed in U.S. Patent Application Publication No. 2003 / 0130535. In one embodiment, the sulfur-containing organosilicon compound is Si-363 from Degussa. The amount of the sulfur-containing organosilicon compound in the rubber composition may vary depending on the level of other additives used. The amount of the compound may be from 0.5phr to 20phr, particularly in the case of tread rubber compositions. In one embodiment, the amount will be from 1phr to 10phr.

[0121] In another embodiment, the rubber composition comprises 0.1 to 5 phr of a cobalt salt, and more preferably 0.2 to 2 phr of a cobalt salt. This content may be of particular interest if used for a ply coating compound, since it may improve the adhesion of the rubber coating to the ply or belt material, especially if such material is a metal, preferably a brass coated metal such as steel. However, in another embodiment, the rubber composition may be substantially free of cobalt, for example comprising less than 0.1 phr of a cobalt salt or 0 phr of a cobalt salt. The cobalt compound will typically be a cobalt salt of a fatty acid or a cobalt salt of an aliphatic or alicyclic carboxylic acid containing 6 to 30 carbon atoms. Some representative examples of cobalt compounds that can be used include cobalt salts, cobalt naphthanate, cobalt linoleate, cobalt stearate, cobalt oleate, cobalt acetate, cobalt neodecanoate, cobalt tallate, cobalt tresinate, cobalt pyruvate, or in situ salts prepared from cobalt hydroxide and organic acids such as naphthenic acid, stearic acid, oleic acid, acetic acid, linoleic acid, etc. Additional cobalt compounds that can be used are available under the trade name Manobond TM C. Known. Manobond TM C is a cobalt complex containing a boron organic acid manufactured by Manchem Company. TM C is described in British Patent No. 972,804, which is incorporated herein by reference in its entirety.

[0122] It is readily understood by those skilled in the art that rubber compositions can be compounded by methods commonly known in the rubber compounding field, such as mixing various sulfur-vulcanizable component rubbers with various commonly used additive materials, such as sulfur donors, curing aids such as activators and retarders, and processing additives such as oils, resins including tackifying resins and plasticizers, fillers, pigments, fatty acids, zinc oxide, waxes, antioxidants and antiozonants and peptizers. As known to those skilled in the art, according to the intended use of sulfur-vulcanizable and sulfur-vulcanized materials (rubbers), the above-mentioned additives are selected and usually used in conventional amounts. Some representative examples of sulfur donors include elemental sulfur (free sulfur), disulfide amines, polymerized polysulfides and sulfur olefin adducts. In one embodiment, sulfur-vulcanizing agents are elemental sulfur. Sulfur-vulcanizing agents can be used, for example, in an amount of 0.5phr to 8phr or 1.5phr to 6phr. If used, the typical amount of tackifying resins includes, for example, 0.5phr to 10phr, typically 1phr to 5phr. If used, a typical amount of a processing aid comprises, for example, 1 phr to 50 phr (this may particularly include oils). If used, a typical amount of an antioxidant may, for example, comprise 1 phr to 5 phr. Representative antioxidants may be, for example, diphenyl-p-phenylenediamine, etc., such as those disclosed in The Vanderbilt Rubber Handbook (1978), pages 344 to 346. If used, a typical amount of an antiozonant may, for example, comprise 1 phr to 5 phr. If used, a typical amount of a fatty acid (which may include stearic acid) may, for example, comprise 0.5 phr to 3 phr. If used, a typical amount of a wax may, for example, comprise 1 phr to 5 phr. Microcrystalline wax is generally used. If used, a typical amount of a peptizing agent may, for example, comprise 0.1 phr to 1 phr. Typical peptizing agents may, for example, comprise pentachlorothiophenol and dibenzamidodiphenyl disulfide.

[0123] Accelerators can be preferably but not necessarily used to control the time and / or temperature required for vulcanization, and to improve the properties of vulcanized rubber. In one embodiment, a single accelerator system, i.e., a primary accelerator, can be used. One or more primary accelerators can be used in a total amount of 0.5phr to 4phr or 0.8phr to 1.5phr. In another embodiment, a combination of a primary accelerator and an auxiliary accelerator can be used, and the auxiliary accelerator is used in a smaller amount, such as 0.05phr to 3phr, to activate and improve the properties of the vulcanized rubber. The combination of these accelerators can be expected to produce a synergistic effect on the final properties, and is better to a certain extent than the effect produced by using any accelerator alone. In addition, delayed action accelerators can be used, which are not affected by normal processing temperatures, but produce satisfactory solidification at ordinary vulcanization temperatures. Vulcanization retarders can also be used. Accelerators of suitable types that can be used for the present invention are, for example, amines, disulfides, guanidines, thioureas, thiazoles, thiurams, sulfenamides, dithiocarbamates / salts and xanthates / salts. In one embodiment, the primary accelerator is a sulfenamide. If a secondary accelerator is used, the secondary accelerator may be, for example, a guanidine, dithiocarbamate or thiuram compound. Suitable guanidines include diphenylguanidine and the like. Suitable thiurams include tetramethylthiuram disulfide, tetraethylthiuram disulfide and tetrabenzylthiuram disulfide.

[0124] The mixing of the rubber composition can be achieved by methods known to those skilled in the art of rubber mixing. For example, the ingredients can be mixed in at least two stages, i.e., at least one non-productive stage, followed by a productive mixing stage. The final curing agent comprising a sulfur-vulcanizing agent can be mixed in the final stage, which is generally referred to as a "productive" mixing stage, wherein the mixing is generally carried out at a temperature or final temperature lower than one or more mixing temperatures of the previous one or more non-productive mixing stages. The terms "non-productive" and "productive" mixing stages are well known to those skilled in the art of rubber mixing. In one embodiment, the rubber composition can be subjected to a thermomechanical mixing step. The thermomechanical mixing step generally includes mechanical processing in a mixer or extruder for a period of time, such as being suitable for producing a rubber temperature of 140° C. to 190° C. The appropriate duration of the thermomechanical processing varies with the operating conditions and the volume and properties of the components. For example, the thermomechanical processing can be 1 to 20 minutes.

[0125] The vulcanization of the pneumatic tire of the present invention can be carried out, for example, at conventional temperatures of 100° C. to 200° C. In one embodiment, the vulcanization is carried out at a temperature of 110° C. to 180° C. Any conventional vulcanization method can be used, such as heating in a press or mold, heating with superheated steam or hot air. Such tires can be built, shaped, molded and cured by various methods that are known and will be apparent to those skilled in the art.

[0126] In a fourth aspect of the invention, the invention relates to a method of building a tyre according to the first and / or second aspect of the invention and / or one or more of the embodiments thereof.

[0127] In one embodiment, the method includes the step of extruding a tread having both a tread cap (optionally including a first tread cap layer and a second tread cap layer), a first tread base layer, and a second tread base layer.

[0128] In another embodiment, the tread is extruded using one of a three-layer, four-layer, and five-layer extruder.

[0129] In yet another embodiment, the tread is extruded with one of the above extruders, optionally with an additional screw for extruding the tread strip according to one of the above embodiments.

[0130] In one embodiment, the tread is extruded using a three-layer extruder, preferably with only one tread cap layer / single cap.

[0131] In one embodiment, the tread is extruded using a four-layer extruder, preferably where the tread cap includes a first tread cap layer and a second tread cap layer.

[0132] In another embodiment, the first tread cap layer, the second tread cap layer, the first tread base layer, and the second tread base layer each comprise or consist of a different rubber composition.

[0133] In yet another embodiment, one or both of the tread base layers include a (integrally formed) skirt portion.

[0134] In yet another embodiment, the tread includes a tread band extending from a radially outer surface of the tread to a radially inner position of the tread and optionally formed integrally with the first tread base layer.

[0135] The above-mentioned aspects, embodiments and features mentioned therein can be combined with one another.

[0136] Figure 1 A tire 1 according to a preferred embodiment of the present invention is shown. The tire 1 has a tread 10, sidewalls 2, 2', a first carcass ply 3, a second carcass ply 4, a first belt layer 5, a second belt layer 6, bead portions 7, 7', beads 8, bead chafers 9, 9', a tread strip 11, a tread base layer 12, 12', a tread cap layer 13, a skirt portion 14, 14', an overlay 15, a (bead) apex 16 and an inner liner 17.

[0137] According to this non-limiting embodiment of the invention, the tread 10 has a single cap construction, or in other words, has a single tread cap layer 13 supported by two axially adjacent tread base layers 12, 12'. In other embodiments (not explicitly shown herein), the tread cap includes multiple tread cap layers, preferably supported by one or more tread base layers. In addition, the tread 10 includes a conductive tread (rubber) strip 11 (sometimes also called a conductive chimney) extending laterally through the tread 10, in particular through the tread cap layer 13. The tread base includes a first tread base layer 12 comprising a first rubber composition and a second tread base layer 12' comprising a different second rubber composition. In this embodiment, the tread strip 11 and the tread base layer 12 are shown as separate components, but they can also be integrally formed as a single component from the same rubber composition. In other words, the tread base layer 12 can have an extension extending laterally from the bottom of the tread toward the radially outer surface of the tread. In addition, the tire 1 of the present embodiment has a wing-shaped or skirt portion 14 arranged between the sidewall 2 and the tread cap layer 13. Although the skirt portion 14 is shown herein as a separate component, the skirt 14 can also be formed integrally with the tread base layer 12 and optionally composed of the same (first) tread base rubber composition. Alternatively, the tire can also not have such a skirt portion at all. For example, in such an embodiment (not shown), the sidewall 2 can directly contact the tread 10.

[0138] For easier orientation, Figure 1-3 , an axial direction a, a circumferential direction c, and a radial direction r are shown. The axial direction a is parallel to the axis of rotation of the tire. The circumferential direction c is parallel to the circumference of the tire, for example, to the equatorial plane of the tire. Furthermore, the radial direction r is perpendicular to the axial direction a and / or the circumferential direction c. When referring to one or more of these directions, such reference is not limited to a specific orientation of these directions unless otherwise specified herein.

[0139] like Figure 1 and 2 As shown, using the same reference numerals where applicable, in order to allow electrical conduction of electrical charge through the tread 10, the tread 10 has an electrically conductive tread strip 11 (comprising or consisting of an electrically conductive tread strip rubber composition). Preferably, the rubber composition or compositions of the tread cap layer 13 and the tread base layer 12' are non-conductive, while the tread strip 11 and the tread base layer 12 (the rubber compositions) are electrically conductive. The skirt portion 14, the sidewall 2 and the chafer 9 are also electrically conductive to provide an electrical path from the bead portion 7 that contacts the rim when mounted on the rim to the radially outer surface of the tread 10. For better understanding, and to illustrate the electrical pathway through the tire 1, the following description is provided. Figure 1 and 21 , the tread strip 11, the tread base 12, the skirt portion 14, the sidewall 2 and the chafer 9 are shown with the same shading. However, it is obvious that these components do not necessarily have the same rubber composition.

[0140] Conductive is understood herein as having a conductivity below 10 8 ohm·cm. Not conductive, or non-conductive / insulating, is understood herein as having a volume resistivity higher than 10 9 Volume resistivity in ohm·cm unless otherwise stated herein.

[0141] In a preferred embodiment, the rubber compositions of the tread strip 11, the tread base 12, the skirt portion 14, the sidewall 2 and the chafer 9 each have more than 50 phr of carbon black.

[0142] As a non-limiting example, the conductive sidewall 2 and / or chafer 9 rubber composition may include 25 phr natural rubber, 75 phr polybutadiene, 70 phr carbon black, 14 phr oil, 2 phr stearic acid, 7 phr antidegradant, 2.5 phr zinc oxide, 2 phr sulfur, and 1.7 phr accelerator. The volume resistivity of the rubber composition has been determined to be less than 1×10 5 ohm·cm. In addition, an indicator of the hysteresis of the rubber compound, tan δ at 10% strain, was determined to be approximately 0.19. G' and tan δ were measured in this paper using an RPA 2000 from Alpha Technologies. TM Rubber Process Analyzer is based on ASTM D5289 or equivalent method.

[0143] Other non-limiting embodiments of such rubber compositions for sidewalls 2 or chafers 9 may include 20 to 50 phr of natural rubber or synthetic polyisoprene, 50 to 80 phr of polybutadiene rubber, 50 to 90 phr (preferably 60 phr or 65 to 85 phr or 80 phr) of carbon black. Optionally, such compositions further include one or more of the following: 1 to 25 phr of oil, 3 to 15 phr of antidegradants (preferably 6 to 10 phr of antidegradants), 0.5 to 5 phr of one or more tackifiers (such as phenolic resins), 0.5 to 5 phr of stearic acid, 0.5 to 5 phr of zinc oxide, 0.5 to 5 phr of sulfur, 0.5 to 4 phr of one or more vulcanization accelerators.

[0144] In one non-limiting example, one or more of the rubber compositions of the tread base 12, skirt 14 and / or tread strip 11 comprises 30 phr of polybutadiene rubber, 40 phr of polyisoprene, 30 phr of styrene butadiene rubber, 70 phr of carbon black, 31 phr of oil, 5 phr of phenolic resin, 3.8 phr of wax, 6.7 phr of antidegradants (here including phenylenediamine type), 1 phr of stearic acid, 0.9 phr of accelerator, 2 phr of zinc oxide and 2.5 phr of sulfur.

[0145] Although some preferred rubber compositions have been provided above, other compositions are possible. In particular, other amounts of natural rubber, polyisoprene, polybutadiene rubber and / or styrene butadiene rubber may be used.

[0146] Considering that Figure 1 The low resistivity of the left-hand (lateral / axial) side of the tire 1 shown can be Figure 1 The right hand side of the tire shown uses non-conductive components. Figure 3 It also describes Figure 1 The right-hand side of the tire 1 shown is used with Figure 1 . In particular, a tread base layer 12' may be used having a second rubber composition which is non-conductive but which has, for example, a lower rolling resistance than the first tread base rubber composition of the tread base layer 12. In addition or alternatively, the skirt portion 14' on the right-hand side of the tire 1 may also be non-conductive. The same applies to the sidewall 2' and the chafer 9' in the bead portion 7'. Although the tread base is shown here with two tread base layers 12, 12', one of which is conductive and the other is not, it is also possible to have only a single tread base or tread base layer comprising only one conductive rubber composition. In particular, this may reduce the construction complexity. In such an embodiment, the sidewall 2' and the chafer 9' will preferably be non-conductive, in other words, contain a limited amount of carbon black which contributes to reducing the overall rolling resistance of the tire. Similar to Figure 1 and 2 The left hand side of the tire 1 is shown in Figure 3 The skirt portion 14' shown in FIG. 1 may be integrally formed with the tread base layer 12', or omitted entirely.

[0147] In one embodiment, the sidewall 2' and / or the chafer 9' has a rubber composition comprising 40 phr natural rubber, 60 phr polybutadiene, 40 phr carbon black, 4 phr oil, 1 phr stearic acid, 3 phr tackifier (e.g. phenolic resin), 8 phr antidegradant, 2 phr zinc oxide, 3.5 phr sulfur, 1 phr accelerator. The volume resistivity of the rubber composition has been determined to be approximately 1.2 x 10 12 The hysteresis indicator tan δ at 10% strain was determined to be 0.07, which is significantly lower than the hysteresis of the rubber compound of the sidewall 2 and / or the chafer 9. In the present embodiment, the same rubber composition has been used for the chafer 9'.

[0148] In an alternative embodiment, the (non-conductive) sidewall 2' and / or chafer 9' rubber composition may comprise 20 to 50 phr of natural rubber or synthetic polyisoprene, 50 to 80 phr of polybutadiene rubber, 0.1 to 45 phr (preferably 0.1 to 40 phr or to 35 phr) of carbon black. Optionally, such a composition further comprises one or more of the following: 1 to 10 phr of oil, 3 to 15 phr of antidegradants (preferably 6 to 10 phr of antidegradants), 0.5 to 5 phr of one or more tackifiers (such as phenolic resins), 0.5 to 5 phr of stearic acid, 0.5 to 5 phr of zinc oxide, 0.5 to 5 phr of sulfur, 0.5 to 4 phr of one or more vulcanization accelerators.

[0149] In one non-limiting example, one or more of the tread base 12' and / or skirt 14' rubber compositions include 30 phr of polybutadiene rubber, 40 phr of polyisoprene, 30 phr of styrene butadiene rubber, 70 phr of silica, 6 phr of silane, 31 phr of oil, 5 phr of phenolic resin, 3.8 phr of wax, 6.7 phr of antidegradants (including phenylenediamines), 1 phr of stearic acid, 0.9 phr of accelerators, 2 phr of zinc oxide, and 2.5 phr of sulfur. In other words, this is an example of a non-conductive tread base and / or skirt rubber composition.

[0150] Although the above rubber compositions are non-limiting preferred examples, other compositions are possible. In particular, other amounts of natural rubber, polyisoprene, polybutadiene rubber and / or styrene butadiene rubber may be used.

[0151] The rubber composition of the apex 16 and the structure of the bead 8 are preferably the same or similar on both lateral sides of the tire to reduce the number of different components used to build the tire 1 .

[0152] In summary, the present invention provides an advanced electrical path between the rim or bead portion of a tire and the road or tire tread. Such a path can be provided at a limited cost and / or with a limited amount of material or a limited number of components. Such tires can also be manufactured efficiently. In addition, a tire with reduced rolling resistance can be provided.

[0153] According to the description provided herein, the present invention can be changed. Although certain representative embodiments and details have been shown for the purpose of illustrating the present invention, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the present invention. Therefore, it should be understood that changes can be made in the specific embodiments described, and these changes will be within the full expected scope of the present invention defined by the appended claims.

Claims

1. A tire comprising a tread, a pair of bead portions, a pair of sidewalls, wherein each sidewall extends from the tread to a respective bead portion, a pair of chafers, at least one carcass ply, and one or more belt layers radially arranged between the tread and the at least one carcass ply in a crown region of the tire, wherein a first sidewall of the pair of sidewalls and a first chafer of the pair of chafers adjacent to the first sidewall have a thickness less than 10 8 ohm·cm volume resistivity. And wherein at least one of i) a second sidewall of the pair of sidewalls and ii) a second chafer of the pair of chafers adjacent to the second sidewall has a thickness greater than 10 9 Volume resistivity of ohm·cm.

2. The tire according to claim 1, wherein the second sidewall has a thickness higher than 10 9 Volume resistivity of ohm·cm.

3. The tire according to claim 1, wherein the second bead filler has a thickness greater than 10 mm with respect to the second sidewall. 9 Volume resistivity of ohm·cm.

4. The tire according to claim 1, wherein the tread comprises a 8 The tread base has a volume resistivity of 0.1 ohm·cm and is in contact with the first sidewall.

5. The tire of claim 4, wherein the tread base further comprises a skirt portion at an axially outer side thereof, which is closest to the first sidewall, wherein the skirt portion has a thickness of less than 10 8 Volume resistivity of ohm·cm.

6. The tire of claim 1, wherein the tread further comprises a tread strip having a thickness of less than 10 8 The volume resistivity is ohm·cm and extends laterally through the tread from a radially outer surface of the tread to a radially inner position of the tread.

7. The tire of claim 6, wherein the tread further comprises at least one tread cap layer and one or more tread base layers, wherein the tread strip extends through at least one tread cap layer to contact at least one of the tread base layers.

8. The tire of claim 7, wherein the tire has a first tread base layer and a second tread base layer, The first tread base layer has a thickness less than 10 8 Volume resistivity in ohm cm, The second tread base layer has a thickness greater than 10 9 Volume resistivity of ohm cm; and Wherein the tread strip contacts at least a first tread base layer.

9. A tire comprising a tread, a pair of bead portions, a pair of sidewalls, wherein each sidewall extends from the tread to a respective bead portion, at least one carcass ply, and one or more belt layers radially disposed between the tread and the at least one carcass ply in a crown region of the tire, The tread comprises a first tread base layer and a second tread base layer, The first tread base layer has a thickness less than 10 8 ohm·cm volume resistivity and wherein the second tread base layer has a volume resistivity higher than 10 9 ohm cm volume resistivity; and The first tread base layer is axially arranged beside the second tread base layer.

10. A tire comprising a tread, a pair of bead portions, a pair of sidewalls, wherein each sidewall extends from the tread to a respective bead portion, a pair of chafers, at least one carcass ply, and one or more belt layers radially disposed between the tread and the at least one carcass ply in a crown region of the tire, wherein each of a first sidewall of the pair of sidewalls and a first chafer of the pair of chafers adjacent to the first sidewall comprises one or more rubber compositions comprising at least 39 phr of carbon black, and wherein at least one of i) a second sidewall of the pair of sidewalls and ii) a second chafer of the pair of chafers adjacent to the second sidewall comprises one or more rubber compositions comprising up to 35 phr of carbon black.

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