Tires with improved rubber compounds

Abstract

According to an aspect of the present invention, a vehicle tire having a tread is provided. The tread comprises a set of continuous blocks arranged along the outer circumference of the tire; a plurality of first grooves arranged across the outer circumference of the tire, each of which is positioned between two blocks of the set of continuous blocks; and a plurality of sipes, each defining an edge component El corresponding to the ratio of the sum of the axial projection lengths SAP of the plurality of sipes to the outer circumference C of the tread. El is at least 2 and at most 20. The tread is made from a rubber composition having an E' of at least 20 MPa and at most 80 MPa at -20°C when measured according to ISO 4664.

Description

[Technical Field]

[0001] This invention relates to vehicle tires. One possible application of the disclosed tire relates to an all-season tire intended for use on passenger cars or commercial vans. This disclosure can also be applied to other tires, such as winter tires, summer tires, or tires for off-road use. [Background technology]

[0002] All-season tires (used here as a typical example for readability) are known for providing good grip on snow-covered roads while also offering good performance on dry and wet roads. Such tires are intended for year-round use and do not require switching between summer and winter tires.

[0003] For example, all-season tires are known to have grooves that extend from the center of the tire tread, i.e., from the tire's equatorial plane, toward the tire's shoulders. These grooves typically extend substantially axially and are configured to deliver water outward from the tire's contact patch with the road surface in order to provide contact between the tire blocks and the road surface. Contact between the blocks and the road is necessary to provide lateral road holding and, furthermore, to provide friction that allows the driver to control the vehicle's movement through acceleration, braking, and / or steering.

[0004] Furthermore, all-season tires are generally known to feature sipes, which are cutouts smaller than grooves. Such sipes are typically intended to trap snow within them and provide an additional edge to the tread profile, thus improving snow performance.

[0005] However, while sipes improve snow performance, they reduce the rigidity of the tread pattern, impairing braking performance, especially on dry surfaces. Therefore, the object of the present invention is to provide a tire having a tread with improved traction characteristics on snow-covered ground while avoiding the loss of braking performance on dry and wet ground due to the loss of block rigidity. [Overview of the Initiative]

[0006] This objective is achieved by providing an improved vehicle tire as described in the independent claim. Further embodiments are described in the dependent claims.

[0007] According to an aspect of the present invention, a vehicle tire having a tread is provided. The tread comprises a set of continuous blocks arranged along the outer circumference of the tire, a plurality of first grooves arranged across the outer circumference of the tire, each of which is positioned between two blocks of the set of continuous blocks, and a plurality of sipes that define an edge component EI corresponding to the ratio of the sum of the axial protrusions SAP of the plurality of sipes to the outer circumference C of the tread.

[0008]

number

[0009] Such tires offer superior traction on snow-covered ground, primarily due to having an EI (Engineering Index) within a specified range. Generally, a higher edge component results in better performance on snow-covered ground. This is because a higher edge component means more sipes that can trap snow and provide additional edge support, increasing the tire's traction on snow. If the EI is too high, i.e., selected to exceed the specified range, the block stiffness is excessively reduced to provide acceptable braking performance on dry ground. If the EI is too low, i.e., selected below the specified range, there are not enough sipes to achieve acceptable snow performance.

[0010] However, even if the EI is within the specified range, the stiffness of the blocks decreases, and the dry braking performance deteriorates. The inventors have found that by manufacturing a tire using the rubber composition defined in the present invention, it is possible to balance the stiffness lost by providing sipes at a specified EI. Therefore, in the tire of this disclosure, the material stiffness, i.e., the stiffness provided by the rubber composition, works synergistically with the structural stiffness, i.e., the stiffness provided by the pattern. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of a vehicle tire according to this disclosure. [Figure 2] The half-tread profile of the tire as disclosed herein is shown. [Figure 3] This disclosure illustrates exemplary embodiments of the V-shaped directional tread pattern. [Figure 4] This disclosure illustrates exemplary embodiments of the S-shaped tread pattern. [Modes for carrying out the invention]

[0012] In order to overcome the drawbacks of the prior art as described above, the present invention aims to provide sipes in the tread of a tire, which are intended to capture snow therein and provide additional edges to improve traction on snow. However, by providing sipes, the structural rigidity of the tread profile is reduced, thereby impairing the dry braking performance of the tire. Therefore, the reduction in structural rigidity is balanced by an increase in material rigidity.

[0013] The inventors have found that by manufacturing a tire from a rubber composition having a specific E', it is possible to balance the rigidity lost by providing sipes at a specified EI. The parameter E' correlates with rigidity. The rubber composition having the E' specified in the present disclosure can be manufactured by using a resin component including a blend of hydrocarbon resins containing a specific ratio of rosin resin and terpene resin.

[0014] An increase in material rigidity can be achieved by manufacturing a tire from the rubber composition as specified.

[0015] FIG. 1 is a schematic view of a vehicle tire according to the present disclosure.

[0016] According to FIG. 1, the tire 100 includes a tread 110. The tread has a set of continuous blocks 10 and grooves 12 disposed between two of the blocks 10 of the set of continuous blocks. Further, sipes 14 may be disposed within each of the set of continuous blocks 1 of the set of continuous blocks 10.

[0017] The blocks may be disposed continuously in the circumferential direction 120 of the tire.

[0018] A "groove" represents an indentation in the tread pattern. The width of the grooves may vary; for example, a first groove may be wider than a second groove, or they may be the same width or even narrower. For example, the width of a groove may be at least 2 mm. The width of a single groove does not necessarily have to be constant. For example, a groove may have a wider width towards the opening of the tread pattern and a narrower width radially inward. The depth of the grooves may also vary; in some cases, the grooves may extend to the total depth of the tread (the total depth of the tread is the maximum radially measured distance between the outermost radial portion of the tire and the bottom of the deepest groove), but this is not necessarily required. For example, a depth of at least 1 mm, preferably at least 3 mm, is conceivable.

[0019] "Sipes" also refer to cuts in the tread pattern. In this specification, "sipes" refer to cuts within a block, rather than "grooves" separating the blocks. For example, the width of a sipe may be smaller than the width of a groove, for example, less than 2 mm. As with grooves, the width of a sipe does not need to be constant; means can be applied to allow it to widen towards the opening of the tread pattern and narrow radially inward. The depth of a sipe may also vary, and in some cases, a sipe may extend to the full depth of the tread block, but this is not necessarily required. For example, a depth of at least 1 mm, preferably at least 20% of the depth of the first groove, is conceivable.

[0020] In the context of this disclosure, “circumferential direction” 120 means a direction parallel to the direction in which the tire normally rolls, i.e., a direction perpendicular to the axial direction 130 which is parallel to the tangential direction to the outer circumference of the tire. With respect to Figure 1, the circumferential direction 120 is therefore a direction that lies in a plane parallel to the yz plane.

[0021] In the context of this disclosure, “axial direction” 130 means the direction parallel to the axis of the vehicle to which the tire is normally mounted. Thus, according to Figure 1, the axial direction 130 is parallel to the x-axis and therefore perpendicular to the yz-plane.

[0022] In the context of this disclosure, “radial direction” 140 means the direction perpendicular to the axial direction. The radial direction is parallel to the connection between the center 150 of the tire and the tread surface. Thus, the radial direction lies in a plane parallel to the yz plane and substantially perpendicular to the axial direction 130 and the circumferential direction 120.

[0023] In the context of this disclosure, “equator plane” refers to a plane perpendicular to the axial direction 130 and cutting the cross-sectional width of the tire into two equal halves. Thus, the equatorial plane is parallel to the yz plane and corresponds to the widthwise centerline of the tread.

[0024] Figure 2 shows the half-tread profile of the tire according to this disclosure.

[0025] As shown in Figure 2, the tread comprises a set of continuous blocks 10 arranged along the outer circumference of the tire. In the context of this disclosure, “continuous blocks” means that the tread comprises a plurality of blocks that are continuous with one another across the outer circumference of the tire. While the present invention is preferably provided for all blocks of the tire, some blocks that may be located between the individual blocks 10 of a set of continuous blocks may not satisfy all claimed requirements.

[0026] In some embodiments described in more detail elsewhere in this specification, the tread comprises additional blocks on the other side of the tire's equatorial plane 16. In some embodiments described elsewhere in this specification, these additional blocks may have an axisymmetric configuration with respect to the block 10 shown in Figure 2, thereby the overall pattern being V-shaped. In other embodiments described elsewhere in this specification, the additional blocks may be point-symmetric, and the overall pattern may be S-shaped. In any case, this disclosure is not intended for any particular orientation of the blocks and can be applied to blocks of various shapes and orientations.

[0027] Furthermore, although this disclosure describes a tread pattern that is substantially symmetrical, i.e., having the same or similar tread configuration on both sides of the equatorial plane, it will be understood that the concepts described herein can also be applied to asymmetrical tread patterns, i.e., patterns having substantially different tread configurations on both sides of the equatorial plane 16 of the tire.

[0028] Generally, the block 10 is intended to provide contact with the ground when the tire is rolling. The edges and surface of the block are configured to provide frictional force between the tire and the ground for grip, enabling general road holding, as well as the driver's control of the vehicle's movement through acceleration, braking, or steering.

[0029] As shown in Figure 2, the tread further comprises a plurality of first grooves 18 arranged around the outer circumference of the tire, each of which is positioned between two blocks 10 of a set of continuous blocks. Preferably, the grooves 18 begin near the equatorial plane 16 of the tire, extend toward the shoulder end of the tread, and open at the outer edge of the tire. The grooves 10 are generally defined by adjacent blocks 10.

[0030] The primary purpose of the grooves 18 is to guide water along the grooves 10 toward the tire's shoulder as the tire rolls on the ground, thereby draining water from the contact patch. Thus, the grooves 18 improve tire performance, especially in wet road conditions. Furthermore, since the grooves define continuous blocks, they also provide edges for the blocks to improve snow performance. In addition, the grooves allow for greater flexibility of the tread elements, thus improving wear performance, resulting in reduced slippage of the blocks on the ground and a decrease in wear-inducing effects.

[0031] As shown in Figure 2, the tread may further comprise a plurality of second grooves 20 that extend substantially circumferentially through each of the set of blocks 10. In some embodiments, the second grooves 20 may penetrate the entire block 10. In other embodiments, the second grooves 20 may be located only in a portion of the circumferential extension of the block 10. Thus, the second grooves 20 may be located in the circumferential central portion of the block 10, or they may be located to simply interrupt one or more edges of the block 10. In some embodiments, each second groove 20 may be located, for example, as a substantially straight line slightly inclined with respect to the circumferential direction, and in other embodiments, for example, as shown in Figure 2, each second groove 20 may be located in a zigzag shape including, for example, three different inclined portions. Such a zigzag configuration of the second grooves 20 allows for partial interruption of the tire's deformation and sliding behavior, and thus improves the distribution of wear energy across the entire axial extension of the block 10.

[0032] The second groove generally serves to separate the portion of block 10 near the tire's shoulder (sometimes referred to as the "shoulder portion") from the portion of the block positioned more inward when viewed axially. For example, during acceleration or braking, the shoulder portion of block 10 is particularly susceptible to deformation because it is positioned substantially perpendicular to the circumferential direction of the tire. This can lead to deformation of block 10 in the shoulder portion. Therefore, it is desirable to mechanically separate the shoulder portion from the rest of block 10 in order to ensure good steering performance and lateral road holding during braking and acceleration. This separation is preferably achieved by providing a second groove 20 between them. In this way, the second portion 14 still provides lateral road holding and steering performance despite the deformation of the shoulder portion. A wider second groove improves the separation effect compared to a narrower second groove.

[0033] As shown in Figure 2, the tread may further comprise a plurality of sipes 14. In the illustrated tread pattern, each of the plurality of sipes 14 may extend substantially along the shape of each of the set of continuous blocks 10. However, other arrangements and shapes of sipes on the outer tread surface are also possible, such as corrugated or zigzag shapes. Sipes do not necessarily have to follow the shape of the blocks. For example, sipes may be included only along a portion of the shape of the block, or they may have a different angle of inclination with respect to the circumferential direction than the underlying block or portion of the block. Also, some sipes may have walls that extend radially toward the center of the tire, while some sipes may have corrugated, zigzag shapes, etc., in the radial direction. Furthermore, such sipes may be inclined with respect to the radial direction. Some sipes may have projections near the bottom of the sipe.

[0034] The 14 sipes can trap snow within them, providing an additional edge to the tread. This improves traction on snow-covered ground.

[0035] In some embodiments, the multiple sipes 14 may define an edge component (EI) corresponding to the ratio of the sum of the axial protrusion lengths (SAP) of the multiple sipes to the outer circumference (C) of the tread, thereby,

[0036]

number

[0037] The tire circumference C is measured at the outermost radial ring of the inflated tire. The same specifications as those described below for tire footprint measurement apply to the inflation pressure and ambient temperature.

[0038] A high edge component provides better ability to capture snow, thereby improving the tire's traction on snow-covered ground. However, a high edge component also results in low block rigidity, which generally deteriorates braking / acceleration performance on dry ground. When the edge component is within any of the above ranges, the balance between traction on snow-covered ground and braking / acceleration performance on dry ground is particularly good.

[0039] The tire according to FIG. 2 further has a void volume which is the volume of all the grooves, sipes, and recesses provided in the tread, and a volume of rubber provided in the tread, and these may together occupy the total volume of the tread. That is, if the total volume of the tire is V T and the void volume is V V and the rubber volume is V R then the total volume V T is V T =V V +V R In a preferred embodiment, the ratio V V of the void volume V R to the rubber volume V V / V R may be at least 0.20 and at most 0.40. Preferably, the ratio V V / V R may be at least 0.24 and at most 0.37, more preferably at least 0.28 and at most 0.35. The ratio V V / VR is directly related to the rigidity of the tread profile. The higher the ratio V V / V R , the greater the amount of voids in the tread, which indicates that by reducing the rigidity of the tread, the braking performance is improved. The lower the ratio V V / V R , the greater the amount of rubber in the tread, which indicates that by increasing the rigidity, the braking performance is improved. A specific range of void-to-rubber ratio provides an optimal trade-off between snow performance and dry performance, and provides a tire that exhibits good braking performance on dry ground and good traction on snow-covered ground.

[0040] As shown in Figure 2, each of the continuous blocks 10 in the set may have a leading edge and a trailing edge.

[0041] In the context of this disclosure, “leading edge” may also be referred to as “traction edge,” and refers to the edge of a block that primarily responds to longitudinal traction forces applied to the tire. Typically, the “leading edge” is longer than the side edge of the block and is the edge of the block that first encounters the ground when the tire block, rolling in the preferred rolling direction, enters the tire-to-ground contact patch.

[0042] The "trailing edge," sometimes called the "braking edge," refers to the edge of the tire block that primarily responds to longitudinal braking forces applied to the tire. Typically, the "trailing edge" is the edge of the block that is longer than the side edge and is the last edge that loses contact with the ground when the tire block, rolling in the preferred direction of rolling, leaves the tire's contact patch with the ground.

[0043] As shown in Figure 2, each block of the set of continuous blocks may further include a chamfered portion located on at least one of its leading edge and trailing edge.

[0044] In the context of this disclosure, “chamfer” means the inclined side wall of a block extending radially inward from the outer block surface. The wall is inclined such that the width of the block, measured circumferentially, increases toward the bottom of the groove. Each chamfer is defined by its height and width. The chamfer height may correspond to the distance, measured radially, between the outer block surface and the radially innermost edge of the inclined wall. The chamfer height (= distance between the outer block surface and the radially innermost edge of the inclined wall) is typically lower than the total height of the block, for example, up to 50% or less of the total height of the block. The chamfer width may be measured perpendicular to the block and corresponds to the width of the inclined chamfer wall when it protrudes above the outer tread surface.

[0045] The chamfered edge of the trailing edge contributes to dry braking performance. When a vehicle brakes, the inertia of the vehicle's mass causes the tread blocks to deform and bend. In this way, some of the rubber surface located near the leading edge of the block loses contact with the road surface, thus reducing the contact area of ​​each block. A reduced contact area reduces friction, and therefore impairs the braking performance of the tire.

[0046] By providing a chamfered edge, the inclined surface of the chamfered portion is pushed towards the ground during braking when the block bends, thus increasing the rubber surface area. In this way, surface loss at the leading edge of the block can be compensated for, increasing the contact surface and resulting in improved braking performance due to increased friction. Therefore, the chamfered portion of the trailing edge of the block contributes to both dry and wet braking performance.

[0047] The chamfered edge of the leading edge has been proven to function efficiently to contribute to traction, especially on snow-covered ground. In general, to increase traction on snow-covered ground, it is necessary to reduce the surface area of ​​the block and increase the contact pressure between the block surface and the ground. Placing the chamfered edge on the leading edge has been shown to be a good location for reducing the surface area of ​​the block. The increased contact pressure provided by the chamfered edge, which results in a peak in contact pressure, particularly at the leading edge of the block, allows the block, and especially its leading edge, to bite into the snow more efficiently, and thus increases the traction of the tire on snow-covered ground.

[0048] Figure 3 shows an exemplary embodiment of the V-shaped directional tread pattern according to this disclosure.

[0049] As shown in Figure 3, some embodiments of the tread may include a second set of continuous blocks 50 that are positioned opposite the equatorial plane 16 of the tire and generally correspond to a first set of continuous blocks 10. In some embodiments, as shown in Figure 3, the second set of continuous blocks 50 can be axially symmetric with respect to the first set of blocks 10, resulting in a V-shaped tread pattern with a preferred rolling direction. The V-shape offers the advantage of improved drainage characteristics, as water can be drained from the contact patch by two opposing first grooves located in the axial directions of the tread on opposite sides when the tire rolls in the preferred rolling direction. This can improve traction on wet surfaces. While directional patterns with a preferred rolling direction are advantageous on wet surfaces, other embodiments are also possible.

[0050] For example, Figure 4 shows an exemplary embodiment of an S-shaped tread pattern according to the present disclosure. In some embodiments, according to Figure 4, the tread may comprise a second set of continuous blocks 50 in addition to a first set of continuous blocks 10. The second set of continuous blocks 50 may be positioned on the opposite side of the tire's equatorial plane 16. In contrast to the embodiments described above, which include a V-shaped tread pattern, the second set of continuous blocks 50 may be provided point-symmetrically with respect to the first set of blocks 10, resulting in an S-shaped tread pattern that does not have a preferred rolling direction.

[0051] Tire footprint measurement In the context of this disclosure, “tire footprint” means all parts of the tire that are in contact with the ground when the tire is rolling. The tire footprint provides information about the behavior of the tread profile in rolling conditions; that is, from the tire footprint, it is possible to know which parts of the blocks are in contact with the ground under static load conditions.

[0052] When analyzing tire footprints, each tire is generally inflated to a pressure appropriate to its type. For standard passenger car radial tires with a nominal section width of 195 mm or less, a tire pressure of 1.9 bar is used. For standard passenger car radial tires with a nominal section width of 205 mm or more, a tire pressure of 2.0 bar is used. For reinforced passenger car radial tires of any size, a pressure of 2.3 bar is used. For tires used in commercial vans and trucks, the standardized inflation pressure set by the European Tire and Rim Technology Association (ETRTO) is used. All measurements are taken at room temperature.

[0053] Next, loads are applied to the tire under the following conditions: For passenger car radial tires, the tire is loaded with a weight equivalent to 88% of the tire load index according to the ETRTO chart. Tires for commercial vans and trucks are loaded with a weight corresponding to the ETRTO single load rating standard. To perform the measurements, ink may be applied to the tread profile, and then the tire may be pressed onto a card according to the above specifications, leaving an ink footprint that can then be analyzed. The footprint is evaluated for three tire sections placed at equal intervals of 120 degrees around the circumference of the tire. The metrics analyzed within the footprint are then averaged across the three measured sections.

[0054] Measurement of tire void volume and rubber volume In the context of this application, the tire void volume is also measured under footprint conditions. That is, the tire is inflated in the same manner as described above for tire footprint measurement. The void volume is measured for each pixel by a laser measurement system capable of detecting the depth of the void relative to the tread surface. Thus, the total void volume within the contact patch can be calculated by integrating over all measured pixels. The total tread volume can be calculated as the product of the tire's footprint width (FW) and circumference (C) divided by the weighted average depth of the first groove. In this case, the total volume of rubber is the difference between the total tread volume and the total void volume.

[0055] The measurements given in this disclosure refer to measurements taken under footprint conditions on new tires that have not been exposed to wear prior to the measurement.

[0056] rubber composition The tire tread of the present disclosure comprises a rubber composition having a specific E'. According to the present disclosure, the rubber composition has an E' of at least 20 MPa and a maximum of 80 MPa at -20°C. In a preferred embodiment, the rubber composition has an E' of at least 20 MPa and a maximum of 60 MPa at -20°C. In another preferred embodiment, the rubber composition has an E' of at least 25 MPa and a maximum of 65 MPa at -20°C. Preferably, the rubber composition has an E' of at least 25 MPa and a maximum of 45 MPa at -20°C. In a further preferred embodiment, the rubber composition has an E' of at least 7.0 MPa and a maximum of 25 MPa at 30°C, and preferably an E' of at least 10.0 MPa and a maximum of 18 MPa at 30°C. The parameter E' refers to the modulus of elasticity at the indicated temperature, i.e., -20°C or 30°C. E' is measured according to ISO 4664.

[0057] In preferred embodiments, the rubber composition comprises at least a rubber component, a resin component, and a filler component. According to this disclosure, the resin component is a blend of at least two hydrocarbon resins A and B. Hydrocarbon resin A is different from hydrocarbon resin B.

[0058] In a more preferred embodiment, hydrocarbon resin A is a rosin resin, and hydrocarbon resin B is selected from the group of hydrocarbon resins including terpene resins. In a preferred embodiment, hydrocarbon resin B contains 30 to 100% by weight of terpene resin, preferably 80 to 100% by weight of terpene resin. In an exemplary embodiment, hydrocarbon resin A is a rosin resin, and hydrocarbon resin B is a terpene resin. In a further preferred embodiment, the resin component comprises rosin resin (hydrocarbon resin A) and hydrocarbon resin B in a ratio of at least 1.2, preferably at least 1.2 and up to 4.0. In an exemplary embodiment, the ratio of hydrocarbon resin A to hydrocarbon resin B is at least 1.5 and up to 3.5, at least 1.7 and up to 3.3, or at least 2.0 and up to 3.0. In an exemplary embodiment, the resin component is present in the rubber composition in an amount of at least 25 phr, preferably at least 30 phr and up to 80 phr, and more preferably at least 35 phr and up to 70 phr.

[0059] The rosin resin is preferably selected from rosin-based resins having a glass transition temperature of at least 20°C, more preferably at least 40°C. The rosin resin or rosin-based resin is a solid resin obtained from pine and other plants, such as conifers. It contains functional groups that may be aromatic carboxylic acid functional groups. In this disclosure, hydrocarbon resin B is selected from a general class of hydrocarbon resins. These hydrocarbon resins are typically selected from the group consisting of cyclopentadiene homopolymer or copolymer resins (abbreviated as CPD), dicyclopentadiene homopolymer or copolymer resins (abbreviated as DCPD), terpene homopolymer or copolymer resins, C5 homopolymer or copolymer resins which may be partially or completely hydrogenated, C9 homopolymer or copolymer resins which may be partially or completely hydrogenated, α-methylstyrene homopolymer or copolymer resins, and combinations thereof. In this disclosure, hydrocarbon resin B includes terpene resins. The terpene resin is preferably selected from terpene-based resins. Terpene resins or terpene-based resins are natural resins derived from plants, such as conifers, and are derived from isoprene, with the formula (C5H8).n It contains an unsaturated hydrocarbon compound having (wherein n>1) in the formula. Suitable hydrocarbon resins and terpene resins as hydrocarbon resin B have a glass transition temperature of at least 55°C, preferably at least 65°C. In preferred embodiments, hydrocarbon resins A and B have specific aromaticity, which is determined by NMR. Preferably, hydrocarbon resin A (rosin resin) has an aromaticity of at least 4.0, preferably at least 5.0, and hydrocarbon resin B and / or terpene resin has an aromaticity of up to 3.0, preferably up to 2.0.

[0060] The following table shows resins particularly suitable for hydrocarbon resin A and hydrocarbon resin B, respectively.

[0061] [Table 1] * The softening point of a material is the temperature at which the material softens beyond a certain degree of softness, and is measured using a ring-ball apparatus according to ISO 4625. In this specification, Tg (glass transition temperature) refers to a measurement obtained by DSC (differential scanning calorimetry) in accordance with the ASTM D3418 (1999) standard.

[0062] In a preferred embodiment, the rubber component of the rubber composition comprises at least one rubber selected from the group consisting of styrene-butadiene rubber (SBR), butadiene rubber (BR), natural rubber (NR), and isoprene rubber (IR). Preferably, the rubber component comprises at least styrene-butadiene rubber. In another preferred embodiment, the rubber composition comprises styrene-butadiene rubber and another rubber selected from the group consisting of butadiene rubber (BR), natural rubber (NR), and isoprene rubber (IR). A suitable rubber composition contains styrene-butadiene rubber in an amount of 40 to 80 phr and at least one further rubber in an amount of 60 to 20 phr. In a preferred embodiment, the rubber component has a glass transition temperature (Tg) of at least -100°C, preferably at least -100°C to a maximum of 110°C. In another preferred embodiment, the glass transition temperature (Tg) of the rubber component is at least -90°C to a maximum of 50°C. In a further preferred embodiment, the rubber component has a glass transition temperature (Tg) of at least -20°C, preferably at least -20°C to a maximum of 110°C.

[0063] In a preferred embodiment, the filler component of the rubber composition includes at least an inorganic filler. In an exemplary embodiment, the filler component further includes carbon black. In a preferred embodiment, the total amount of inorganic filler in the rubber composition is at least 70 phr to a maximum of 200 phr, more preferably at least 80 phr to a maximum of 180 phr, and even more preferably at least 90 phr to a maximum of 160 phr. In an exemplary embodiment, the inorganic filler is selected from silica, mineral fillers, calcium carbonate, clay, alumina, aluminosilicates, and combinations thereof. The mineral fillers may be of natural or synthetic origin and may include alumina, aluminum hydroxide (oxide), and / or magnesium oxide.

[0064] In exemplary embodiments, the rubber composition includes a silane that functions to bond the silica filler to the polymer backbone by covalent bonds. Any silane that satisfies this function can be used. Suitable silane coupling agents include bis(3-triethoxysilylpropyl)tetrasulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(3-triethoxysilylpropyl)disulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide It may be one or more selected from the group consisting of rubamoyl tetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis(3-diethoxymethylsilylpropyl)tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, and dimethoxymethylsilylpropylbenzothiazolyl tetrasulfide. A commercially available silane is Si69 of bis(triethoxysilylpropyl)tetrasulfide. The silane can be present in an amount of 5 to 13 phr.

[0065] Suitable curing or vulcanization systems for the rubber compositions of this disclosure are not limited and are known in the art. Exemplary systems include sulfur, TbZTd (tetrabenzyl thiuram disulfide), DPG (diphenylguanidine), MBTS (mercaptobenzothiazole salt), DCBS (N'-dicyclohexyl-2-benzothiazole sulfenamide), CBS (N-cyclohexyl-2-benzothiazole sulfenamide), and / or TBBS (N-tert-butyl-2-benzothiadyl sulfenamide).

[0066] In exemplary embodiments, the rubber composition further comprises a liquid plasticizer which may be selected from naphthenic, paraffinic, MES (weakly extracted solvate), TDAE (treated distillate aromatic extract) oil, RAE (residual aromatic extract), mineral oil, or vegetable oil. The rubber composition may also contain further additives, such as degradation inhibitors (e.g., antioxidants or ozone degradation inhibitors), waxes, and processing agents.

[0067] Preferred rubber compositions of this disclosure are shown in the table below. Unless otherwise specified, this table shows the preferred amount (phr) of each component.

[0068] [Table 2] * The term "curing package" refers to curing or vulcanizing components.

[0069] The components of the rubber composition are mixed in a manner known to those skilled in the art and are not limited thereto.

[0070] The present invention also provides a cured rubber composition obtained after curing of the rubber composition of the present disclosure.

[0071] The following examples illustrate the present invention without limiting the scope of protection. [Examples]

[0072] In the following examples, rubber compositions were prepared and tested for E'.

[0073] The following resins were used.

[0074] [Table 3]

[0075] A rubber composition was prepared by blending each component according to the following formulation.

[0076] [Table 4] * The silane used was Si69. ** N'-(1,3-dimethylbutyl)-N'-phenyl-1,4-benzenediamine

[0077] Furthermore, a rubber composition was prepared according to the above formulation, and instead of 35 phr of rosin resin and 15 phr of terpene resin, 50 phr of rosin resin or 50 phr of terpene resin was used.

[0078] The cured rubber compositions were tested for E' at -20°C and E' at +30°C, with measurements performed according to ISO 4664. Furthermore, the rubber compositions were evaluated for their wet and snow performance. E' at -20°C is a predictor of snow performance; a higher value indicates worse snow performance. The parameter E' at 30°C affects both wet and dry performance. A higher E' at 30°C indicates better wet performance. Wet performance was evaluated on an external demonstration surface using a wet braking track. Wet braking performance was evaluated as a function of the braking distance traveled from an initial speed (80 km / h) to a final speed (20 km / h) on a wet surface. Snow performance was evaluated on an external demonstration surface using a snow track. Snow performance was evaluated by the average of two metrics: snow braking performance, which is measured by the braking distance from initial speed (40 km / h) to final speed (5 km / h) on a snow surface, and snow traction performance, which is measured by the acceleration time (seconds) from initial speed (5 km / h) to final speed (35 km / h) on a snow surface.

[0079] The following results were obtained.

[0080] [Table 5]

[0081] As shown, the blend provides the best balance between performance characteristics.

[0082] As the results show, the use of a blend of hydrocarbon resins, including rosin and terpene resins, increases the material stiffness of the rubber composition, allowing it to compensate for the reduction in stiffness caused by sipes.

[0083] Further preferred embodiments of the present invention are described below. 1. A vehicle tire having a tread, wherein the tread is A set of continuous blocks arranged along the outer circumference of the tire, A plurality of first grooves arranged around the outer circumference of the tire, each of the plurality of first grooves being positioned between two blocks of a set of consecutive blocks, A plurality of sipes, wherein the sipes define an edge component EI corresponding to the ratio of the sum of the protruding lengths SAP of the plurality of axial sipes to the outer circumference C of the tread,

[0084]

number

[0085] 10, 50 blocks 12 The first groove 14 sipes 16 Equatorial plane 20 The second groove 100 tires 110 tread 120 circumferential direction 130 Axis 140 Radial 150 center

Claims

1. A vehicle tire having a tread, wherein the tread is A set of continuous blocks arranged along the outer circumference of the aforementioned tire, A plurality of first grooves arranged over the outer circumference of the tire, each of the plurality of first grooves comprising a plurality of first grooves arranged between two blocks of the set of continuous blocks, A plurality of sipes, wherein the sipes determine an edge component EI corresponding to the ratio of the sum of the axial protrusion lengths of the plurality of sipes SAP to the outer circumference C of the tread, [Math 1] The aforementioned EI is at least 2 and at most 20, A vehicle tire in which the tread is made from a rubber composition having an E' of at least 20 MPa and a maximum of 80 MPa at -20°C, as measured according to ISO 4664.

2. The tire according to claim 1, wherein the tread has a ratio of void volume to rubber volume of at least 0.20 and at most 0.

40.

3. Each of the consecutive blocks in the aforementioned set is The leading edge and, The trailing edge and, The tire according to claim 1 or 2, comprising a chamfered portion disposed on at least one of the front edge and the rear edge.

4. A plurality of second grooves, each of which is located in one of the continuous blocks of the set, further comprising a plurality of second grooves, The tire according to any one of claims 1 to 3, wherein the plurality of second grooves are substantially arranged in the circumferential direction.

5. The tire according to any one of claims 1 to 4, wherein the tire has a preferred rolling direction.

6. The tire according to any one of claims 1 to 5, wherein the rubber composition comprises at least a rubber component, a resin component, and a filler component, and the resin component is a blend of at least two hydrocarbon resins A and B.

7. The tire according to claim 6, wherein the hydrocarbon resin A is a rosin resin, and the hydrocarbon resin B is selected from the general group of hydrocarbon resins including terpene resins.

8. The tire according to claim 7, wherein the hydrocarbon resin B comprises 30 to 100% by weight of a terpene resin.

9. The tire according to claim 7 or 8, wherein the resin component comprises the rosin resin and the hydrocarbon resin B in a ratio of at least 1.2, preferably at least 1.2 and up to 4.

0.

10. The tire according to any one of claims 6 to 9, wherein the amount of the resin component in the rubber composition is at least 25 phr.

11. The tire according to any one of claims 7 to 10, wherein the rosin resin is selected from rosin resins having a glass transition temperature of at least 20°C.

12. The tire according to any one of claims 7 to 11, wherein the hydrocarbon resin B is selected from hydrocarbon resins having a glass transition temperature of at least 55°C.

13. The tire according to any one of claims 7 to 12, wherein the rosin resin has an aromaticity of at least 4.0, and the hydrocarbon resin B and / or the terpene resin has an aromaticity of up to 3.

0.

14. The tire according to any one of claims 6 to 13, wherein the rubber composition comprises a rubber component comprising at least one rubber selected from the group consisting of styrene-butadiene rubber (SBR), butadiene rubber (BR), natural rubber (NR), and isoprene rubber (IR), and preferably the rubber component comprises at least styrene-butadiene rubber.

15. The tire according to claim 14, wherein the rubber composition comprises 40 to 80 phr of styrene-butadiene rubber and 60 to 20 phr of at least one further rubber.

16. The tire according to any one of claims 6 to 15, wherein the rubber component of the rubber composition has a glass transition temperature (Tg) of at least -100°C to a maximum of 110°C, preferably at least -90°C to a maximum of 50°C.

17. The tire according to any one of claims 6 to 16, wherein the filler component comprises at least an inorganic filler.

18. The tire according to claim 17, wherein the total amount of the inorganic filler in the rubber composition is at least 70 phr and at most 200 phr, and preferably the inorganic filler is selected from silica, mineral fillers, calcium carbonate, clay, alumina, aluminosilicate, and combinations thereof.

19. The tire according to any one of claims 1 to 18, wherein the rubber composition has an E' of at least 25 MPa and a maximum of 65 MPa at -20°C when measured according to ISO 4664.

20. The tire according to any one of claims 1 to 19, wherein the rubber composition has an E' of at least 7.0 MPa and a maximum of 25 MPa, preferably at least 10.0 MPa and a maximum of 18 MPa at 30°C, as measured according to ISO 4664.

21. Use of the tire described in any one of claims 1 to 20 as an all-season tire for vehicles.

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