Vehicle tyre comprising a tread, and tread composition

Abstract

The invention relates to a vehicle tyre which contains, at least in one tread (1), a vulcanisate which is obtained by sulphur vulcanisation of a rubber mixture which contains at least the following constituents: a) 5 to 100 phr of at least one butadiene rubber, the butadiene rubber being functionalised for coupling to carbon black as a filler; b) 5 to 95 phr of carbon black as a filler, preferably industrial-grade carbon black, wherein a void volume of the tread is between 0% and 20%, preferably at least 2% to at most 15%.

Description

[0001] 202402829

[0002] - 1 -

[0003] Description

[0004] Vehicle tires with tread and tread composition

[0005] The invention relates to a vehicle tire, in particular a commercial vehicle tire. Furthermore, the invention relates to the tread of a vehicle tire and a sulfur-curable rubber compound for the tread.

[0006] The rubber composition of the tread largely determines the properties of a vehicle tire. Therefore, these rubber compounds for the tread are subject to high demands, particularly regarding abrasion resistance / mileage, wet braking performance, and tire rolling resistance.

[0007] The terms "tread strip" and "tread surface" are to be considered synonymous in relation to the present text.

[0008] Wear and mileage are indicators of the same tire characteristic. High wear means low tire mileage, and vice versa. Mileage can generally be increased by a low void volume in the tread pattern.

[0009] In the case of a low void volume in the tread pattern, the contact area between the tire and the road surface is comparatively large. The friction between the tire and the road surface is then lower compared to tires with a higher void volume, so wear and rolling resistance are generally reduced. This increases mileage.

[0010] The rolling resistance (RR) of tires is measured by drum tests. Rolling resistance drum test measurements are the basis for legal rolling resistance certifications, the awarding of rolling resistance labels, and the verification of rolling resistance limit requirements. These rolling resistance drum test measurements are based on 202402829

[0011] - 2 - on tests according to ISO 28580. Low rolling resistance is preferred to minimize friction losses and energy consumption.

[0012] On the other hand, a lower void volume in the tread usually reduces wet braking performance.

[0013] Mileage and tire rolling resistance on the one hand, and wet braking performance on the other, are therefore properties that are typically in conflict with each other.

[0014] The present invention was based on the objective of providing a rubber compound for treads and a corresponding tread or tire with treads which, compared to the prior art, exhibits an improvement in the property profile, in particular with regard to the conflict of objectives between mileage, rolling resistance behavior and wet braking behavior.

[0015] Surprisingly, the rubber compound, vulcanizate, tread, and vehicle tire according to the invention improve the tire's performance profile, particularly with regard to the described conflict of objectives.

[0016] The invention encompasses all advantageous embodiments, which are reflected, inter alia, in the claims. In particular, the invention also encompasses embodiments resulting from the combination of different features, for example, components of the rubber compound or elements of the tire, with varying degrees of preference given to these features, such that a combination of a first feature designated as "preferred" or described within the framework of an advantageous embodiment with a further feature designated, for example, as "particularly preferred," is also encompassed by the invention.

[0017] The following section describes in more detail the components of the rubber compound according to the invention and the properties of the tread produced therefrom. 202402829

[0018] - 3 -

[0019] All information relating to the components of the rubber compound according to the invention, regardless of the degree of preference given to these features, also applies accordingly to the vulcanizate according to the invention, the tread according to the invention, the (commercial) vehicle tire according to the invention, and uses according to the invention.

[0020] The unit phr (parts per hundred parts of rubber by weight) used in this document is the standard unit of measurement for compound formulations in the rubber industry. The dosage of the parts by weight of the individual substances is based on 100 parts by weight of the total mass of all rubbers present in the mixture with a molecular weight Mw according to GPC greater than 20,000 g / mol. The specified value ranges always include the limit values.

[0021] According to the invention, the rubber mixture contains at least one diene rubber, which is a butadiene rubber (synonyms: BR, BR rubber, polybutadiene).

[0022] Diene rubbers are rubbers that are formed by polymerization or copolymerization of dienes and / or cycloalkenes and thus have C=C double bonds either in the main chain or in the side groups.

[0023] According to the invention, the proportion of BR in the rubber mixture is at least 5 phr and at most 100 phr. In the latter case, the rubber component of the rubber mixture consists of BR.

[0024] Preferably, the proportion of BR in the rubber mixture is at least 10 phr, more preferably at least 15 phr, more preferably at least 20 phr, more preferably at least 25 phr, more preferably at least 30 phr, more preferably at least 40 phr, and even more preferably at least 50 phr.

[0025] Preferably, the proportion of BR in the rubber compound is a maximum of 90 phr, more preferably a maximum of 80 phr, and even more preferably a maximum of 70 phr. The butadiene- 202402829

[0026] - 4 -

[0027] Rubber is not one of the other possible diene rubbers listed below.

[0028] According to the invention, the BR used is functionalized for the binding of soot as a filler, as explained in detail below.

[0029] According to the invention, the rubber mixture can further contain at least one diene rubber from the group consisting of natural polyisoprene (NR) and synthetic polyisoprene (IR) with a proportion of at most 95 phr.

[0030] Preferably, the rubber mixture consists of BR and NR. That is, the proportions of BR and NR in phr preferably add up to 100 phr.

[0031] According to the invention, the rubber mixture can alternatively or additionally contain the diene rubber styrene-butadiene rubber (SBR), in particular solution-polymerized styrene-butadiene rubber (SSBR) or emulsion-polymerized styrene-butadiene rubber (ESBR), preferably SSBR. According to the invention, the proportion of SBR in the rubber mixture is at most as high as the proportion of BR.

[0032] Other possible diene rubbers that may be present in smaller quantities in the mixture according to the invention are butadiene-isoprene rubber, styrene-isoprene rubber, halobutyl rubber, polynorbornene, isoprene-isobutylene copolymer, ethylene-propylene diene rubber, nitrile rubber, chloroprene rubber, acrylate rubber, fluorocarbon rubber, silicone rubber, polysulfide rubber, epichlorohydrin rubber, styrene-isoprene-butadiene terpolymer, hydrogenated acrylonitrile butadiene rubber and hydrogenated styrene-butadiene rubber.

[0033] In this process, plasticizers, vulcanization systems and additives known to experts for these rubbers are used preferentially.

[0034] The inventive use of butadiene rubber (BR) and NR or IR and / or SSBR particularly effectively solves the problem underlying the invention. 202402829

[0035] - 5 -

[0036] The sum of the contained rubbers, by definition, equals 100 phr.

[0037] The BR rubber used in the present rubber compound can be polymerized using organometallic catalysts, e.g. with neodymium, cobalt, titanium, nickel, lithium, sodium or other catalysts or Ziegler-Natta catalysts.

[0038] It can be BR rubber with a high cis content (high-cis) or low cis content (low-cis) or with a high or low trans content (high-trans, low-trans).

[0039] The glass transition temperature (Tg) of the BR is preferably below - 75 °C, more preferably below - 85 °C, more preferably below - 95 °C.

[0040] The BR rubber used in the present rubber compound preferably has a molar mass between 300,000 and 600,000 g / mol.

[0041] It is also possible to mix several of the aforementioned BR rubbers.

[0042] The BR rubber used is end-group modified and / or functionalized along the polymer chains according to the fillers used. The BR rubber can be modified simply or with any number of modifications. These modifications can include hydroxy groups, ethoxy groups, epoxy groups, siloxane groups, amino groups, aminosiloxane groups, carboxy groups, phthalocyanine groups, and / or silane sulfide groups.

[0043] However, other modifications, also known as functionalizations and known to experts, are also possible. Metal atoms can be part of such functionalizations.

[0044] These functionalizations or modifications are specifically selected for the filler used, in particular according to the invention specifically for carbon black fillers or e.g. 202402829

[0045] - 6 - also silica fillers. The terms "silica", "silica" and "silicon dioxide" are used synonymously within the scope of the present invention.

[0046] The BR rubber used in the present rubber compound is always functionalized, at least specifically, for the binding of carbon black.

[0047] The functionalized BR rubber can have several functionalizations and, for example, can also be additionally functionalized for interaction with silica.

[0048] The combination results in an unexpectedly significant performance advantage for the rubber compound. A marked improvement in wet braking performance is unexpectedly observed, even with low cavity volumes.

[0049] The BR rubber used is preferably functionalized for bonding Carbon Black.

[0050] A preferred vinyl content of the BR rubber used is between 10% and 30%, more preferably between 15% and 25%. Unless otherwise stated, the percentages given in this text are by weight.

[0051] The BR used can be crude oil-based. Preferably, the BR used can also be partially or fully based on recycled, renewable, and / or bio-based raw materials. This BR from renewable raw materials can be obtained, for example, from wood, beets, potatoes (peels), fruits (skin), or byproducts of biodiesel production, such as glycerin.

[0052] All rubber materials used can be based on recycled, renewable and / or bio-based raw materials or on recycled material, e.g. recycled rubber, in particular recycled natural rubber or IR / BR / SSBR recycled rubber.

[0053] According to the invention, the rubber mixture contains as a further component 5 to 95 phr carbon blacks, preferably selected from industrial carbon blacks (English "Carbon Black") and 202402829

[0054] - 7 -

[0055] Pyrolysis soots, with industrial soots or carbon black being further preferred. The amount of soot is preferably at least 10 phr, more preferably at least 20 phr, more preferably at least 30 phr, more preferably at least 40 phr, more preferably at least 50 phr. The amount of soot is preferably at most 90 phr, more preferably at most 80 phr, more preferably at most 70 phr, more preferably at most 60 phr.

[0056] The carbon blacks known to experts for rubber mixtures can be used for this purpose.

[0057] The carbon blacks used also include so-called "recovered" carbon blacks, meaning carbon blacks that have been reclaimed or recycled. The carbon blacks used may also be oxidized.

[0058] The high carbon black content in the rubber compound surprisingly results in advantageous wet braking properties when the rubber compound is used in a tire tread profile, especially in combination with a low void volume of the tread profile.

[0059] The rubber compound according to the invention can also contain at least one further filler. For example, the rubber compound contains as a further component at least one silica, preferably up to 50 phr silica, preferably at least 5 phr silica.

[0060] The filler used (e.g., carbon black or silica or other fillers) may consist partially or entirely of recycled, renewable and / or bio-based material, e.g., recovered or recycled filler or filler based on sustainable or renewable raw materials, e.g., silica based on rice husks or carbon black based on vegetable oil, such as palm oil, rapeseed oil, etc.

[0061] Other optional non-reinforcing fillers within the scope of the present invention include, for example, aluminosilicates, kaolin, chalk, starch, magnesium oxide, 202402829

[0062] - 8 -

[0063] Titanium dioxide or rubber gels as well as fibers (such as aramid fibers, glass fibers, carbon fibers, cellulose fibers).

[0064] Other potentially reinforcing fillers include, for example, carbon nanotubes (CNTs) including discrete CNTs, so-called hollow carbon fibers (HCF) and modified CNTs containing one or more functional groups, such as hydroxy, carboxy and carbonyl groups), graphite and graphene and so-called "carbon-silica dual-phase filier".

[0065] Furthermore, the rubber compound may contain common additives in usual proportions by weight, which are preferably added during its manufacture in at least one basic mixing stage. These additives include:

[0066] 1) Anti-aging agents and ozone-protecting waxes such as diamines, like N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-ditolyl-p-phenylenediamine (DTPD), N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine (7PPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), and / or dihydroquinolines, like 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), and / or substituted bisphenols, like 2,2'-methylenebis(4-methyl-6-tert-butylphenol) (BPH), and / or substituted phenols, like butylhydroxytoluene (BHT),

[0067] 2) Activators, such as zinc oxide and fatty acids (e.g., stearic acid) and / or other activators, such as zinc complexes like zinc ethylhexanoate,

[0068] 3) Further activators and / or agents for binding fillers, in particular carbon black, such as S-(3-aminopropyl)-thiosulfuric acid and / or its metal salts. 202402829

[0069] - 9 -

[0070] 4) Hydrocarbon resins, in particular phenolic resins, especially as adhesive resins,

[0071] 5) Mastication aids, such as 2,2'-dibenzamidodiphenyldisulfide (DBD) and

[0072] 6) Process aids, in particular fatty acid esters and metal soaps, such as e.g.

[0073] Zinc soaps and / or calcium soaps I) Plasticizers, such as in particular aromatic, naphthenic or paraffinic mineral oil plasticizers, such as MES (Mild Extraction Solvate) or RAE (Residual Aromatic Extract) or TDAE (Treated Distillate Aromatic Extract), or Rubber-to-Liquid (RTL) oils or Biomass-to-Liquid (BTL) oils, preferably with a polycyclic aromatic content of less than 3 wt% according to method IP 346, or triglycerides, such as rapeseed oil, or Faktisse, or hydrocarbon resins or liquid polymers, whose mean molecular weight (determined by GPC = gel permeation chromatography, in accordance with BS ISO 11344:2004) is between 500 and 20000 g / mol.

[0074] When using mineral oil, it is preferably selected from the group consisting of DAE (Destilled Aromatic Extracts), RAE (Residual Aromatic Extract), TDAE (Treated Destillated Aromatic Extracts), MES (Mild Extracted Solvents) and naphthenic oils.

[0075] The quantity of other additives in the total quantity is preferably 3 to 100 phr, particularly preferably 3 to 50 phr, and most preferably 5 to 30 phr. Preferably, the rubber mixture contains no other components.

[0076] The rubber compound according to the invention is preferably used in vulcanized form, particularly in the treads of vehicle tires.

[0077] The terms "vulcanized" and "crosslinked" are used synonymously within the scope of the present invention. 202402829

[0078] - 10 -

[0079] The vulcanization of the rubber compound according to the invention is preferably carried out in the presence of sulfur and / or sulfur donors using vulcanization accelerators, wherein some vulcanization accelerators can also act as sulfur donors. The accelerator is selected from the group consisting of thiazole accelerators, mercapto accelerators, sulfenamide accelerators, thiocarbamate accelerators, thiuram accelerators, thiophosphate accelerators, thiourea accelerators, xanthate accelerators, and guanidine accelerators. Preferably, at least one sulfenamide accelerator is selected from the group consisting of N-cyclohexyl-2-benzothiazole sulfenamide (CBS), N,N-dicyclohexylbenzothiazole-2-sulfenamide (DCBS), benzothiazole-2-sulfene morpholide (MBS), N-tert-butyl-2-benzothiazole sulfenamide (TBBS), N-tert-butyl-2-benzothiazole sulfenimide (TBSI), and / or at least one guanidine accelerator, such as diphenylguanidine (DPG).

[0080] In particular, two or more accelerators can also be used.

[0081] Any sulfur-donating substance known to experts can be used as the sulfur-donating substance.

[0082] Furthermore, one or more reversion protectants, such as 1,6-bis(N,N-dibenzylthiocarbamoyldithio)hexane, hexamethylene-1,6-bis(thiosulfate) disodium salt dihydrate, and / or tetrabenzylthiuram disulfide (TBzTD), may be used in the rubber compound.

[0083] Furthermore, vulcanization retarders may be present in the rubber compound.

[0084] The production of the rubber compound otherwise follows the usual procedure in the rubber industry, in which a base mixture with all components except the vulcanization system (e.g. sulfur and vulcanization-influencing substances) is first prepared in one or more mixing stages.

[0085] - 11 - is produced. The finished mixture is produced by adding the vulcanization system in the mixing stages, preferably in the last mixing stage.

[0086] The finished compound is further processed, for example by extrusion or calendering, and formed into the appropriate shape. The rubber compound according to the invention is particularly suitable for use as a tread in vehicle tires, especially pneumatic tires. Such a tread can be composed of several layers. In the case that the tread is composed of several layers, this invention relates to the radially outer region of the tread.

[0087] For use as tread in vehicle tires, the mixture is prepared as a ready-made mixture and shaped accordingly before vulcanization, and then applied and vulcanized as usual during the production of the vehicle tire blank.

[0088] As already explained at the outset, the subject matter of the present invention is in particular a vehicle tire and a tread in the vehicle tire, which comprises at least one vulcanizate made from the vulcanized rubber compound according to the invention.

[0089] Furthermore, the present invention also includes tread compounds for hot retreaded tires and for cold retreaded tires, in which PCTs (Pre-Cured-Treads, pre-vulcanized treads for cold retreading of tires) are used, comprising rubber compounds of the described formulation.

[0090] Within the scope of the present invention, vehicle tires are understood to include pneumatic and solid rubber tires as well as non-pneumatic tires such as spoked tires, including tires for industrial and construction vehicles, truck, car and two-wheeler tires.

[0091] In particular, the present invention relates to commercial vehicle tires, which are designed, for example, for trucks and other commercial vehicles. 202402829

[0092] - 12 -

[0093] The tread is preferably constructed in two layers in the radial direction and consists of a tread cap containing the profiling (also referred to as the tread profile in this text) and a radial rubber plate extending within the tread cap, the tread base. The tread base extends axially across the width of the tread cap, but can also be wider or narrower than the tread cap in the axial direction.

[0094] Alternatively, the tread can also be constructed in three or four layers in the radial direction.

[0095] At least the tread cap then comprises the vulcanizate according to the invention with the composition according to the invention or consists of it.

[0096] Further, partly optional, features are also described below in relation to the figure.

[0097] Optionally, the vehicle tires according to the present invention can have two to six belt plies, with angles for individual belt plies from 0° to 90°, including parallel (0°) and intersecting (90°) belt plies. The belt plies can, for example, have steel cord reinforcements or other non-steel cord reinforcements, such as aramid, glass fiber, carbon fiber, synthetic fibers, or cord.

[0098] Preferably, the vehicle tires have a tread profile with a low void volume between 0% and 20%, preferably a minimum of 2% to a maximum of 15%, more preferably a maximum of 12%, and particularly preferably a maximum of 10% (see also the definition of void volume according to EP 2 292 448 B1 below).

[0099] Possible tread profiles include, for example, ribbed profiles, grooved profiles, slatted profiles, or block profiles. Groove or slatted geometries can be oriented laterally (90°) or circumferentially (0°), or with a constant or alternating direction between 0° and 90° relative to the circumferential direction. The directions, geometries, or widths of the slats can change along the tread. Profiles 202402829

[0100] - 13 - can, for example, have 1 to 10 circumferential grooves across the entire width of the tread. The profiles can, for example, have 30 to 600 transverse grooves or lamellae per circumferential rib.

[0101] Possible configurations include lateral or circumferential grooves or lamellae with rectangular grooves or grooves with a radially increasing or decreasing width. Other possibilities include constant groove widths from the groove base to the running surface or varying groove widths from bottom to top.

[0102] The invention comprises tires with different base geometries and base thicknesses or base volumes.

[0103] A commercial vehicle tire and its configurations are known, for example, from EP 3 611 036 B1.

[0104] The invention will now be explained in more detail using comparative and exemplary embodiments.

[0105] The examples according to the invention are marked with E1 and E2 or E3, the comparative examples with V1 and V2.

[0106] The mass fractions in phr are given in Table 1.

[0107] Table 1:

[0108] 202402829

[0109] - 14 -

[0110] In the examples according to the invention, a BR functionalized for bonding carbon black was used. An exemplary BR rubber usable for the present invention has, for example, a glass transition temperature Tg = -88 °C. The molar mass is between 300,000 and 600,000 g / mol. A potentially suitable BR rubber would be BR 500 from ENEOS Materials Corporation.

[0111] The mixture was produced according to the procedure commonly used in the rubber industry.

[0112] Test specimens were produced from the mixtures V1 and E1 by vulcanization to t95 to t100 (measured on the Moving Die Rheometer according to ASTM D 5289-12 / ISO 6502) under pressure at 140 °C and stirred for 30 minutes, and material properties typical for the rubber industry were determined with these test specimens using the test procedures specified below.

[0113] • Shore A hardness at room temperature (RT) according to ISO 868,

[0114] Rebound elasticity at room temperature (RT) according to ISO 4662, 202402829

[0115] - 15 -

[0116] • Stress value at 300% elongation (M 300) at RT, tensile strength and elongation at break at room temperature (RT), according to DIN 53 504.

[0117] Table 2:

[0118] As can be seen in Table 2, the vulcanizate according to the invention exhibits a similar behavior to the comparison vulcanizate, particularly at room temperature.

[0119] Tire tests were also carried out.

[0120] The tires have a small cavity volume (determination of cavity volume according to EP 2 292 448), which was varied between 10% and 15% for the present tests.

[0121] The tread depth is 15 mm.

[0122] The tire treads comprise vulcanized rubber compounds according to V1 or EI.

[0123] As described in EP 2 292 448 B1, the treads of pneumatic tires for commercial vehicles have circumferential grooves which divide the tread into circumferential ribs, wherein an envelope running parallel to the tread periphery in the tread, which touches the deepest circumferential groove from the radial inside, together with the tread periphery and shoulder-side flank sections defines a tread gross volume and all grooves in the tread define the cavity volume.

[0124] The tire rolling resistance was measured in the drum test according to ISO 28580. 202402829

[0125] - 16 -

[0126] Furthermore, the wet braking performance was measured. For this purpose, the SAW braking performance, i.e., the braking performance using ABS (an anti-lock braking system) on wet asphalt, was measured according to UNECE Regulation 117. The braking ability (here synonymous with braking performance) of the reference tires with rubber compounds V1 or V2 on the treads was evaluated in Tables 3A and 3B, each as a reference with a braking ability of 100%.

[0127] Table 3A compares the wet braking performance of tires with dimensions 315 / 70 R 22.5" with a tread rubber composition V1 or a tread rubber composition V1 according to the invention, each with a void volume of 15%. The wet braking performance is considered on both asphalt (rough surface) and concrete (smooth surface).

[0128] Table 3A:

[0129] As can be seen in Table 3A, the braking performance (always wet braking) is surprisingly higher with a void volume of 15% when the composition E1 according to the invention is used in the vulcanizate for the tread. This applies to both asphalt and concrete.

[0130] Furthermore, Table 3B compares the wet braking properties of tires with a rubber composition V2 for the tread or with the inventive rubber compositions E2 or E3 for the tread in the presence of an undesirably high void volume of over 15%. The wet braking properties are considered on asphalt (rough surface).

[0131] Furthermore, the wet braking properties of the tires with a rubber composition V2 of the tread or the rubber compositions E2 or E3 of the tread according to the invention are improved when a low void volume according to the invention is significantly below 15%, namely at 202402829

[0132] - 17 -

[0133] 11.5% compared. Wet braking performance is considered on asphalt (rough surface).

[0134] Table 3B:

[0135] The use of the composition according to the invention in the vulcanizate for the tread, in combination with low void volumes of 15% or less, leads to a surprising improvement in braking performance. Particularly at low void volumes of a maximum of 12%, the inventive effect of increased braking performance is surprisingly pronounced.

[0136] Table 4 compares the wet braking properties of standard tires 1 and 2 on asphalt with variations in the tread profile and thus the cavity volume.

[0137] The tread pattern features grooves running along the circumference of the tire and ribs arranged between them (intermediate ribs), as well as shoulder ribs that limit the grooves to the outside (in the axial direction).

[0138] Table 4:

[0139] As shown in Table 4, braking performance (always wet braking) is generally higher when the cavity volume is larger. Empirically, a correlation of 1.5%, or more generally 1 to 2% improvement in braking performance per 1% increase in cavity volume can be observed.

[0140] - 18 -

[0141] The cavity volume can be determined. Such a decrease in braking performance with a decrease in cavity volume can be avoided or mitigated by using the rubber compositions according to the invention as described above.

[0142] Table 5 compares the rolling resistance according to ISO 28580 for standard tires of size 385 / 65 R22.5" when varying the cavity volume with the same tread profile.

[0143] It is empirically demonstrated that a lower cavity volume leads to an improvement in rolling resistance behavior, meaning that the rolling resistance and thus the friction losses of the tire decrease with decreasing cavity volume and increase with higher cavity volume.

[0144] Rolling resistance is given in Table 5 as a relative value based on 100% rolling resistance at 0% void volume. A higher percentage corresponds to a (undesirable) higher rolling resistance. A higher void volume results in a higher rolling resistance force or lower rolling resistance performance.

[0145] Table 5:

[0146] Furthermore, empirical observations and the state of the art document CN 102001264 A also show that a decrease in cavity volume of 1% leads to an increase in mileage or a decrease in abrasion of approximately 2 to 3%.

[0147] As can be seen from Tables 4 and 5 and the empirical observations described above, tires with a low void volume, preferably below 15%, advantageously exhibit high mileage or low wear and good rolling resistance performance, i.e., low rolling resistance. 202402829

[0148] - 19 -

[0149] Furthermore, tires with a low void volume exhibit lower wet braking performance than tires with a higher void volume. Surprisingly, the effect of the reduced braking performance at low void volumes in the relevant area can be advantageously reduced or (over-)compensated by using the rubber compound according to the invention in the tread.

[0150] In this way, the described conflict of objectives can be resolved, and tires with low void volume, which have high mileage or low abrasion and good rolling resistance performance, i.e., low rolling resistance, can be provided, which, through the use of the rubber compound according to the invention in the tread, also have good braking properties, i.e., high braking performance.

[0151] At low void volumes in the tread profile, the rubber compound according to the invention, with a high proportion of (carbon black) soot as a filler and with BR modified for the bonding of soot as a polymer, results in a surprisingly advantageous increase in wet braking performance, even when the proportion of other fillers such as silica is reduced.

[0152] Figure 1 further shows an exemplary embodiment of the tread strip 1 comprising a vulcanizate of the rubber compound according to the invention.

[0153] Fig. 1 shows, in particular, the usual components of a commercial vehicle tire in radial construction, a tread 1, radially within the tread 1 a belt reinforcement 2, a radial carcass 3 reinforced with reinforcing material and an airtight inner layer 4.

[0154] The tread 1 has a two-layer structure in the radial direction and consists of a tread cap 5 containing the profiling and the vulcanizate according to the invention, and a tread base 6 extending radially within the tread cap 5. In this figure, the tread base 6 extends axially across the width of the tread cap 5. 202402829

[0155] - 20 -

[0156] In the illustrated embodiment, the tread 1 has within the

[0157] The tread 5 features circumferential grooves 7, which have the tread depth typical for commercial vehicle tires. These circumferential grooves 7 divide the tread 1 into continuous profile ribs 8, which can be block-shaped or consist of profile blocks.

[0158] The tread cap 5 is manufactured from the rubber compound according to the invention. The base 6 can be made from the same or another suitable rubber compound.

[0159] 202402829

[0160] - 21 -

[0161] Reference symbol list

[0162] 1 tread

[0163] 2 belts 3 radial carcass

[0164] 4 inner layer

[0165] 5 tread strip cap

[0166] 6 tread base

[0167] 7 Circumferential groove 8 Profile rib

Claims

202402829 - 22 - Patent claims 1. A vehicle tire comprising at least in one tread (1) a vulcanizate obtained by sulfur vulcanization of a rubber compound containing at least the following components: a) 5 to 100 phr of at least one butadiene rubber, wherein the butadiene rubber is functionalized for the binding of carbon black as a filler, preferably at least 10 phr, more preferably at least 20 phr, more preferably at least 25 phr, more preferably at least 30 phr, more preferably at least 40 phr, more preferably at least 50 phr of the butadiene rubber, further preferably at most 90 phr, more preferably at most 80 phr, more preferably at most 70 phr of the butadiene rubber; b) 5 to 95 phr of carbon black as a filler, preferably industrial carbon black, more preferably at least 10 phr, more preferably at least 20 phr, more preferably at least 30 phr, more preferably at least 40 phr phr, even more preferably a minimum of 50 phr of soot, further preferably a maximum of 90 phr, more preferred a maximum of 80 phr, more preferred a maximum of 70 phr,even more preferably a maximum of 60 phr of carbon black, wherein a void volume of the tread is between 0% and 20%, preferably a minimum of 2% to a maximum of 15%, more preferably a maximum of 12%, even more preferably a maximum of 10%.

2. Vehicle tire according to claim 1 comprising the following further component in the rubber compound: c) a maximum of 95 phr polyisoprene, wherein the proportion of polyisoprene and the proportion of butadiene rubber in the rubber compound preferably add up to 100 phr.

3. Vehicle tires according to claim 1 or 2 comprising the following further component in the rubber compound: e) a styrene-butadiene rubber, preferably a solution-polymerized styrene-butadiene rubber.

4. Vehicle tires according to one of claims 1 to 3, wherein the rubber compound does not contain any further rubber components. 202402829 - 23 - 5. Vehicle tire according to any one of claims 1 to 4, wherein the rubber compound further comprises silica, preferably a maximum of 50 phr silica, more preferably a minimum of 5 phr silica.

6. Vehicle tires according to any one of claims 1 to 4, wherein the rubber compound comprises 3 to 100 phr, preferably 3 to 50 phr and particularly preferably 5 to 30 phr of additives in addition to the aforementioned components and preferably no further components.

7. Vehicle tires according to any one of claims 1 to 6, wherein the raw materials used in the rubber compound are partially or completely based on recycled, renewable and / or bio-based raw materials, wherein preferably all rubber materials used in the rubber compound are based on recycled, renewable and / or bio-based raw materials, in particular on recycled natural rubber and / or on IR recycled rubber and / or on BR recycled rubber and / or on SSBR recycled rubber.

8. Vehicle tires according to any one of claims 1 to 7, wherein the butadiene rubber used in the rubber compound is partially or completely based on recycled, renewable and / or bio-based raw materials, preferably based on one or more of wood, beets, potatoes, fruits or by-products of biodiesel production such as glycerin.

9. Vehicle tires according to any one of claims 1 to 8, wherein the filler(s) used in the rubber compound consists partly or entirely of recycled, renewable and / or bio-based material, with carbon black based on vegetable oil being preferred as the filler.

10. Vehicle tire according to any one of claims 1 to 9, wherein the tire is a new tire, a hot retreaded tire or a cold retreaded tire, and is a pneumatic tire, a solid rubber tire or a non-pneumatic tire with spoke construction. 202402829 - 24 - 11. Vehicle tire according to one of claims 1 to 10, wherein the tire is a commercial vehicle tire.

12. Pre-vulcanized tread for the cold retreading of vehicle tires, comprising at least one rubber compound according to any one of claims 1 to 9.

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