CROSS-LINKABLE RUBBER COMPOUND AND PNEUMATIC VEHICLE TIRES

Description

[0001] The invention relates to a crosslinkable rubber mixture and a pneumatic vehicle tire with at least one tire component made of rubber and at least partially made of this rubber mixture.

[0002] In order to optimize the physical properties of vulcanizates made from rubber compounds, which, for example, are used in components of pneumatic vehicle tires or technical rubber articles such as belts, straps, and hoses, it is known to vary the compound components of the rubber compounds. Often, varying one compound component can improve one vulcanizate property while simultaneously deteriorating another, resulting in a trade-off between these vulcanizate properties. In the case of treads of pneumatic vehicle tires, such a trade-off exists between rolling resistance, wet grip properties, and abrasion resistance.

[0003] To influence the rolling resistance, wet grip properties, and abrasion resistance of treads, it is known, for example, to use styrene-butadiene rubbers with different microstructures or modified styrene-butadiene rubbers in the underlying rubber compound(s). In particular, the styrene and vinyl content of styrene-butadiene rubbers can be varied, the end groups modified, or coupling or hydrogenation can be performed.

[0004] EP 2 060 604 B1, for example, discloses a rubber mixture intended particularly for a tread of a pneumatic vehicle tire. This rubber mixture contains a filler and a low-molecular-weight diene rubber with an average molar mass (MW) of 2,000 g / mol to 150,000 g / mol and an aromatic vinyl compound content of less than 5%. A tread made from such a rubber mixture is said to have low rolling resistance.

[0005] WO 2018 / 191187 A1 also discloses a rubber mixture containing a functionalized resin with a polar linker. The rubber mixture is used, for example, in the production of a hose, a seal, a belt, a shoe sole, or a tire component, in particular a tread or a sidewall.

[0006] EP 1529806 A1 discloses a rubber compound for tire treads containing a liquid polymer with a glass transition temperature T g of less than -15 °C. The rubber compounds known to date have not yet succeeded in satisfactorily resolving the conflicting objectives of low rolling resistance, good wet grip properties, and high abrasion resistance that arise in the treads of pneumatic vehicle tires.

[0007] The invention is therefore based on the object of providing a rubber mixture for a tread of a pneumatic vehicle tire by means of which the conflict of objectives between rolling resistance, wet grip properties and abrasion resistance is resolved in a better way than before.

[0008] According to the invention, this is achieved by a crosslinkable rubber mixture containing: a) a diene rubber with an average molar mass of more than 150,000 g / mol, b) a filler, c) a poly- or oligomer with an average molar mass Mn of less than 150,000 g / mol, which has a filler-interacting functional group and a glass transition temperature Tg < -15°C, d) a poly- or oligomer with an average molar mass Mn of less than 150,000 g / mol, which has a filler-interacting functional group and a glass transition temperature Tg > -15°C, wherein the temperature difference ΔT g determined between the glass transition temperature T g of the poly- or oligomer according to feature c) and the glass transition temperature T g of the poly- or oligomer according to feature d) is at least 5°C, wherein the filler-interacting functional groups cause the poly- or oligomer to interact with the filler surface via van der Waals, dipole-dipole or electrostatic interactions or via covalent or non-covalent bonds, such as hydrogen bonds.

[0009] In such a rubber mixture, the mixture components containing a filler-interacting functional group, namely components c) and d), interact more intensively with the filler and create an interface between the polymer or oligomer and the filler. By combining filler-interacting polymers and / or oligomers with different glass transition temperatures, the properties of this interface are optimized, particularly in a way that is tailored to the specific application of the rubber mixture. In a series of tests conducted by us (see below), it has surprisingly been found that treads or treads made from such rubber mixtures.Tread parts are expected to have advantageous wet grip properties (loss factor tan d at 0°C as a wet grip indicator) and low rolling resistance (loss factor tan d at 70°C as a rolling resistance indicator), while continuing to have good abrasion resistance.

[0010] According to a preferred embodiment, the rubber mixture contains silica and / or carbon black as filler.

[0011] According to a further preferred embodiment, the poly- or oligomer according to feature c) is a diene-based poly- or oligomer.

[0012] According to a further preferred embodiment, the poly- or oligomer according to feature c) has a glass transition temperature T g of < -20°C, in particular of < -30°C.

[0013] According to a further preferred embodiment, the polymer or oligomer according to feature c) has an average molar mass Mn (number average molar mass according to

[0014] Gel permeation chromatography) of 500 g / mol to 50,000 g / mol, in particular of 1,000 g / mol to 20,000 g / mol, particularly preferably of 3,000 g / mol to 15,000 g / mol.

[0015] A further preferred embodiment is characterized in that the poly- or oligomer according to feature c) is functionalized with a silyl protecting group.

[0016] Furthermore, it is preferred if the poly- or oligomer according to feature c) is a polybutadiene functionalized with a filler-interacting functional group.

[0017] Furthermore, it is preferred if the poly- or oligomer according to feature c) and / or the poly- or oligomer according to feature d) is functionalized with a silyl protecting group of the formula IV: (R 1< R 2< R 3< )Si- Formula IV where R 1< , R 2< , R 3< are independently selected from the group of linear or branched alkoxy, cycloalkoxy, alkyl, cycloalkyl, aryl or hydroxy groups, each having 1 to 20 carbon atoms, or hydrogen and wherein the silyl protective group according to formula IV is attached directly or via a bridge to the polymer chain of the poly- or oligomer and wherein the bridge is formed from a saturated or unsaturated hydrocarbon radical which may contain heteroatoms, in particular sulfur and / or nitrogen.

[0018] Furthermore, it is preferred if the poly- or oligomer according to feature d) is functionalized with a silyl protecting group of the formula V: -[Z k -X n -R 4< -(CH 2 ) m -Si(R 5< ) p ] q Formula V where Z represents an aromatic or aliphatic group optionally with one or more heteroatom(s), X represents a linker containing sulfur and / or oxygen and / or nitrogen and / or a carbonyl group, R 4< represents one or more aliphatic groups having 1 to 18 carbon atoms and / or a linking group having at least one heteroatom, in particular with oxygen, nitrogen or sulfur, R 5< represents a branched or unbranched alkoxy, aryloxy, alkyl or aryl group having 1 to 18 carbon atoms, hydrogen or a hydroxy group, where at least one R 5< is an alkoxy or aryloxy group having 1 to 18 carbon atoms, a hydrogen atom or a hydroxy group, where R 5< is the same or different within the molecule, q represents an integer ≥ 1, k represents 0 or 1, n represents an integer between 1 and 10, m represents an integer between 0 and 10 and p represents 1, 2 or 3 stands.

[0019] Furthermore, it is preferred if the poly- or oligomer according to feature d) is a resin based on unsaturated aliphatic monomers, unsaturated aromatic monomers, terpenes, rosin, unsaturated cycloaromatic monomers, unsaturated cycloaliphatic monomers, unsaturated fatty acids, methacrylates and / or vinylaromatic monomers.

[0020] Furthermore, it is preferred if the poly- or oligomer according to feature d) has a molar mass (Mn) of 200 g / mol to 150,000 g / mol, preferably of 200 g / mol to 50,000 g / mol, particularly preferably of 200 g / mol to 30,000 g / mol.

[0021] Furthermore, it is preferred if the polymer or oligomer according to feature c) and the polymer or oligomer according to feature d) are present in a ratio of 1:50 to 50:1, in particular of 1:10 to 10:1, preferably of 1:5 to 5:1, and particularly preferably of 1:3 to 3:1.

[0022] Furthermore, it is preferred if the temperature difference between the glass transition temperature T g of the poly- or oligomer according to feature c) and the glass transition temperature T g of the poly- or

[0023] Oligomer according to feature d) is at least 10°C.

[0024] Furthermore, it is preferred if the rubber mixture contains at least one silane coupling agent. The silane coupling agent allows the filler to interact more effectively with the polymers or oligomers.

[0025] The invention further relates to a pneumatic vehicle tire comprising at least one rubber tire component, in particular a tread, which is manufactured at least partially from a rubber mixture according to one of claims 1 to 13. Such a tread exhibits good wet grip properties, low rolling resistance, and high abrasion resistance. In particular, the conflict of objectives that otherwise exists between these properties is resolved particularly favorably.

[0026] Further features, advantages and details of the invention will now be explained in more detail with reference to test series which include embodiments of the invention and are summarized in tables.

[0027] The invention relates to a rubber mixture that is particularly well suited for the production of a tire component or a component of a tire component, in particular a tread or a tread layer. Within the scope of the test series, rubber mixtures were produced and examined with regard to certain vulcanizate properties. Rubber mixtures prepared according to the invention were compared with comparative rubber mixtures (reference rubber mixtures). Production of rubber compounds:

[0028] The rubber compounds were produced under standard conditions in several stages in a laboratory mixer (300 mL, Brabender Mixer, CW Brabender GmbH & Co., South Hackensack, NJ, US). In the first mixing stage (basic mixing stage), all components of the respective rubber compound were mixed, with the exception of at least some components of the crosslinking system, in particular with the exception of sulfur and accelerator. By mixing in the crosslinking system or any remaining components of the crosslinking system, the finished rubber compound (finished mix) was obtained in a further mixing stage (final mix stage). Table 1 lists the mixing parameters, i.e., the conditions under which the rubber compounds were produced. The usual tolerance ranges of + / - 3°C apply to the temperatures. Table 1: Mixing parameters First mixing stage Rotor speed [revolutions / minute] 70 Starting temperature [°C] 130 Final temperature [°C] 149 Second mixing stage Rotor speed [revolutions / minute] 55 Temperature [°C] 80 Vulcanizate tests:

[0029] Standardized, vulcanized test specimens (vulcanization conditions: time = 20 min, temperature = 160°C) were prepared from all rubber compounds, with which some typical vulcanizate properties were determined. The following vulcanizate tests were conducted: Shore A hardness at room temperature (25°C) using a durometer according to DIN ISO 7619-1, loss factor tan d (tan δ) at 0°C and at 70°C from temperature-dependent dynamic-mechanical measurement using an Eplexor according to DIN 53 513 (constant force, 10% compression, ±0.2% strain amplitude, frequency 10 Hz), abrasion test at room temperature (25°C) according to DIN ISO 4649

[0030] These vulcanizate properties allow conclusions to be drawn about the expected properties of a tread made from such a rubber compound or a radially outermost tread layer made from such a rubber compound, which comes into contact with the ground during driving.

[0031] The Shore A hardness is in particular a measure of the stiffness of the vulcanizates.

[0032] The loss factor tan d at 0°C serves as an indicator of a tire's wet grip. The higher the loss factor tan d at 0°C, the better the wet grip properties.

[0033] The loss factor tan d at 70°C serves as an indicator of the rolling resistance of a tire, whereby a smaller loss factor tan d at 70°C means a lower rolling resistance.

[0034] In the abrasion test, a standardized test specimen is rubbed, and the abrasion (amount of abraded material) is determined in mm3. The smaller the abrasion value, the higher (better) the abrasion resistance. Test series carried out:

[0035] Several test series were conducted to investigate the effects of specific blend components on the aforementioned vulcanizate properties. These specific blend components include resins functionalized with a silyl protecting group ((R 1< R 2< R 3< )Si-) on a side group or terminally, as well as polybutadienes functionalized with a silyl protecting group at the terminal. In the following, explicit reference to the silyl protecting group will no longer be made in connection with the test series. Therefore, a "side-group functionalized resin" refers to a resin functionalized with a silyl protecting group at a side group, a "terminally functionalized resin" refers to a resin functionalized with a silyl protecting group at the terminal, and "terminally functionalized liquid polybutadiene" refers to liquid polybutadiene functionalized with a silyl protecting group at the terminal.

[0036] To quantify the functionalization, the mole fraction functionalized with silyl protecting groups is partially given below. The mole fraction refers to the constitutional repeating unit, which is known to be the smallest repeating unit within a polymer.

[0037] In the following description and in the tables, the quantities of the components of the rubber compounds are given in the unit phr (parts per hundred parts of rubber by weight), which is common in rubber technology. The quantities refer to the mass parts of the base polymer or, in the case of polymer blends, to those of the base polymers.

[0038] In the test series tables, which indicate the compositions of the rubber compounds, the corresponding current trade names (as of October 2019) for some compound components are given in parentheses. The test series include examples of inventive rubber compounds E1 to E19 as well as reference rubber compounds R1 to R10. 1. Test series - Variation of the resin quantity

[0039] Table 2.1 shows the compositions of the rubber compounds of the first test series. In the first test series, the basic effects of terminally functionalized liquid polybutadiene (BR) in combination with a terminally functionalized resin were investigated (corresponding quantities in Table 2.1 are highlighted in grey).

[0040] All rubber compounds of the first test series contain an SBR rubber as the base polymer and a silica as the filler.

[0041] The terminally functionalized, liquid polybutadiene is not counted among the base polymers; it is included in addition to the base polymer (SBR rubber) ("on top").

[0042] The terminally functionalized resin a is an α-methylstyrene-based resin in which a molar fraction of 10% is functionalized with silyl protecting groups. Resin a was synthesized according to Example 1.2 of WO 2018 / 191187 A1 (paragraphs

[0229] to

[0231] ) and has an average molar mass Mn (number average molar mass according to gel permeation chromatography) of 699 g / mol. Resin a was present in rubber mixtures E1 to E4 in amounts of 10 phr, 15 phr, 20 phr, and 30 phr, respectively.

[0043] Formula I shows the structural formula of resin a.

[0044] It also contains a silane (bis(3-triethoxysilylpropyl) disulfide), a silane coupling agent, and a sulfur or sulfur donor suitable for sulfur crosslinking. Other mixture components include two accelerators (N-cyclohexyl-2-benzothiazole sulfenamide and 1,3-diphenylguanidine), two activators (stearic acid, zinc oxide), a processing aid, and an anti-aging agent (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine).

[0045] Table 2.2 shows the results of the vulcanizate tests carried out for the rubber compounds from Table 2.1. Table 2.2: 1st test series - vulcanizate tests Vulcanizate properties R1 R2 R3 R4 E1 E2 E3 E4 Shore A hardness (T= 25°C) 70,1 66,2 65,4 66,9 67,6 67,4 68,2 66,7 tan d (0°C) 0,203 0,144 0,298 0,347 0,210 0,233 0,265 0,331 tan d (70°C) 0,112 0,078 0,122 0,161 0,087 0,082 0,088 0,091 Abrasion [mm 3< ] 100 98 126 142 104 109 111 126

[0046] As a comparison of the vulcanizates from R1 and R2 shows, the sole use of terminally functionalized liquid polybutadiene (R2) leads to a lower loss factor tan d (0°C) (wet grip indicator) and a lower loss factor tan d (70°C) (rolling resistance indicator). Consequently, a tread made from the reference rubber compound R2 exhibits poorer wet grip properties and lower (improved) rolling resistance compared to a tread made from the reference rubber compound R1. The abrasion resistance of the vulcanizates from R1 and R2, and thus also of the corresponding treads, is similar (100 vs. 98).

[0047] A comparison of the vulcanizates from R1 and R3 shows that the sole use of terminally functionalized resin (R3) leads to a higher loss factor tan d (0°C) (wet grip indicator) and a higher loss factor tan d (70°C) (rolling resistance indicator). A tread made from the reference rubber compound R3 therefore exhibits better wet grip properties and a higher (worsened) rolling resistance compared to a tread made from the reference rubber compound R1. The abrasion resistance of the vulcanizate from R3 is significantly worse than that of the vulcanizate from R1 (126 vs. 100).

[0048] As the vulcanizate from R4 demonstrates in comparison to the vulcanizates from R3 and R1, the use of larger amounts of terminally functionalized resin (R4) further increases the loss factor tan d (0°C) (wet grip indicator), but the loss factor tan d (70°C) (rolling resistance indicator) is also significantly increased. A tread made from the reference rubber compound R4 therefore exhibits very good wet grip properties, but a very high (significantly reduced) rolling resistance. Furthermore, the vulcanizate from R4 exhibits a very high and therefore poor abrasion value (142 vs. 126 and 100, respectively).

[0049] The vulcanizates made from the rubber mixtures E1 to E4 according to the invention exhibit a higher loss factor tan d (0°C) (wet grip indicator) than the vulcanizates made from the reference rubber mixtures R1 and R2, and a lower loss factor tan d (70°C) (rolling resistance indicator) than the vulcanizates made from the reference rubber mixtures R1, R3, and R4. A tread made from the rubber mixtures E1 to E4 according to the invention therefore exhibits better wet grip properties than a tread made from the reference rubber mixture R1, R2, and significantly lower (improved) rolling resistance than a tread made from the reference rubber mixture R1, R3, and R4. The abrasion resistance of the vulcanizates from E1 to E4 is, in some cases, significantly improved compared to the abrasion resistance of the vulcanizates from R3 and R4.

[0050] The first series of tests shows that the vulcanizates made from the rubber mixtures E1 to E4 according to the invention (containing terminally functionalized liquid polybutadiene in combination with a terminally functionalized resin) provide improved wet grip properties and an improved rolling resistance value without compromising their abrasion resistance. 2nd series of experiments - linker of the resin

[0051] In a second series of experiments, the effects of another terminally functionalized resin (resin b), which differs from the terminally functionalized resin a used in the first series of experiments by the linker, were investigated.

[0052] The terminally functionalized resin b is an α-methylstyrene-based resin in which a molar fraction of 10% is functionalized with silyl protecting groups. Resin b was synthesized according to Example 1.9 of WO 2018 / 191187 A1 (paragraphs

[0248] to

[0249] ) and has an average molar mass Mn of 775 g / mol.

[0053] Formula II shows the structural formula of resin b. Table 3.2: 2nd test series - vulcanizate tests Vulcanizate properties R1 R5 E5 Shore A hardness (T= 25°C) 70,1 62,9 66,7 tan d (0°C) 0,203 0,330 0,346 tan d (70 °C) 0,112 0,117 0,098 Abrasion [mm 3< ] 100 148 117

[0054] Compared to the vulcanizate from R1 or R5, the E5 vulcanizate exhibits a higher loss factor tan d (0°C) (wet grip indicator) and a lower loss factor tan d (70°C) (rolling resistance indicator). A tread made from the inventive rubber compound E5 therefore exhibits better wet grip properties and lower (improved) rolling resistance compared to a tread made from the reference rubber compound R1 or R5. Abrasion resistance is significantly improved compared to the R5 vulcanizate.

[0055] The second series of experiments shows that the advantageous vulcanizate properties can be achieved regardless of the structure of the resin linker. 3. Test series - Base of the resin and position of the functionalization of the resin

[0056] A third series of experiments demonstrated that the beneficial effects can also be achieved with resins functionalized at a side group, as well as with resins with a different base than the resins in the first and second series of experiments (α-methylstyrene base in the first and second series of experiments). Table 4.1 contains the corresponding compositions of the rubber compounds.

[0057] Resin d, functionalized at a side group, is an α-methylstyrene-based resin in which a molar fraction of 10% is functionalized with silyl protecting groups. Resin d was synthesized according to Example 1.4 of WO 2018 / 191187 A1 (paragraphs

[0235] to

[0237] ) and has an average molar mass Mn of 534 g / mol.

[0058] Resin e, functionalized at a side group, is a methacrylate-based resin in which a molar fraction of 10% is functionalized with silyl protecting groups. Resin e was synthesized according to Example 1.8 of WO 2018 / 191187 A1 (paragraphs

[0246] and

[0247] ) and has an average molar mass Mn of 876 g / mol. Table 5.2: 3rd test series - vulcanizate tests Vulcanizate properties R7 R8 E12 E13 E14 E15 E16 E17 Shore A hardness (T= 25°C) 70,9 70 70,2 70,2 70,8 69 67,6 67,2 tan d (0°C) 0,233 0,249 0,247 0,228 0,231 0,244 0,248 0,276 tan d (70 °C) 0,093 0,116 0,097 0,088 0,088 0,104 0,098 0,112 Abrasion [mm 3< ] 108 114 89 98 96 88 84 83

[0059] The vulcanizates from E12 to E14 (corresponding rubber compounds contain terminally functionalized liquid polybutadiene and methacrylate-based resin functionalized on side groups) show a significant improvement in abrasion (89 or 98 or 96 vs. 108) compared to the vulcanizate from R7 (corresponding rubber compound contains "only" methacrylate-based resin functionalized on side groups), whereby the loss factor tan d (0°C) (wet grip indicator) and the loss factor tan d (70°C) (rolling resistance indicator) are retained.

[0060] The vulcanizates from E15 to E17 (corresponding rubber compounds contain terminally functionalized liquid polybutadiene and side-group functionalized α-methylstyrene-based resin) show a smaller tan d (70°) (i.e. reduced rolling resistance for treads) and a significantly improved abrasion (88 or 84 or 83 vs 114) compared to the vulcanizate from R8 (corresponding rubber compound contains "only" side-group functionalized α-methylstyrene-based resin).

[0061] The third series of tests shows that the advantageous vulcanizate properties, in particular the abrasion resistance, can be achieved regardless of the position (side group, end group) of the functionalization of the resin and regardless of the base of the resin. 4. Test series - amount of polybutadiene, type of polybutadiene, resins with different molar mass and different functionalization positions

[0062] In a fourth series of experiments, the effects of varying amounts of terminally functionalized, liquid polybutadiene were investigated, using both the aforementioned POLYVEST EP ST-E 60 and Ricon 603. Ricon 603 differs from POLYVEST EP ST-E 60 in its glass transition temperature T g , its vinyl content, and the ratio of cis to trans isomers (cis / trans ratio). The aforementioned terminally functionalized resin b (Mn of 775 g / mol) and a side-functionalized resin c were used.

[0063] The resin c functionalized at a side group was synthesized by radical copolymerization according to Example 1.5 of WO 2018 / 191187 A1 (paragraphs

[0238] to [0241) and has an average molar mass Mn of 5320 g / mol.

[0064] Formula III shows the structural formula of resin c. Table 4.2: 4th test series - vulcanizate tests Vulcanizate properties R5 R6 E6 E7 E8 E9 E10 E11 Shore A hardness (T= 25°C) 62,9 66,2 67,6 67,4 68,2 63,9 65 66,1 tan d (0°C) 0,330 0,252 0,234 0,217 0,203 0,340 0,343 0,378 tan d (70°C) 0,117 0,119 0,099 0,094 0,085 0,084 0,075 0,070 Abrasion [mm 3< ] 148 123 112 108 103 107 109 135

[0065] As a comparison of the vulcanizates made from rubber compounds R5, E9, E10, and E11 containing resin b shows, the described advantageous effects can also be achieved with Ricon 603. Thus, the vulcanizates made from rubber compounds E9, E10, and E11 - each compared to the vulcanizate made from the reference rubber compound R5 - exhibit a higher loss factor tan d (0°C) (wet grip indicator) and a lower loss factor tan d (70°C) (rolling resistance indicator); they therefore provide treads with better wet grip and rolling resistance properties. In particular, the vulcanizates from the rubber compounds E9, E10, E11 - compared to the vulcanizate from the reference rubber compound R5 - each show a significantly larger difference between their value for tan d (0°C) and their value for tan d (70°C), which suggests a particularly favorable solution to the conflict of objectives between wet grip properties and rolling resistance.Surprisingly, the vulcanizates from rubber compounds E9, E10, and E11 also exhibited better abrasion resistance than the vulcanizate from the reference rubber compound R5 (107, 109, 135 vs. 148). Small amounts of Ricon 603 (E9, E10) were very beneficial for abrasion resistance.

[0066] A comparison of the vulcanizates made from rubber compounds R6, E6, E7, and E8 containing resin c demonstrates the influence of POLYVEST EP ST-E 60. Compared to the vulcanizate made from rubber compound R6, the vulcanizates made from rubber compounds E6, E7, and E8 exhibit lower values ​​for the loss factor tan d (0°C) (wet grip indicator), lower values ​​for the loss factor tan d (70°C) (rolling resistance indicator), and lower values ​​for abrasion. The rubber compounds E6, E7, and E8 therefore produce treads that are more abrasion-resistant and have improved rolling resistance.

[0067] The fourth series of experiments shows that the advantageous vulcanizate properties can be achieved independently of the glass transition temperature (T g ), the vinyl content, and the ratio of cis to trans isomers (cis / trans ratio) of the polybutadienes. Furthermore, it was shown that the position (end group or side group) of the resin functionalization and its molar mass have no or only a negligible influence. 5. Test series - Diene rubbers and filler quantity

[0068] In this series of tests, rubber compounds containing both SBR rubber and natural rubber (SBR / NR blends) as well as higher filler quantities than the previous rubber compounds were tested.

[0069] The SBR rubber used in the fifth series of experiments is HPR 840, a functionalized styrene-butadiene copolymer whose preparation is described, for example, in EP 2 703 416 A1. HPR 840 is functionalized at one chain end with an amino group- and / or with an ammonium group-containing silyl protecting group. Such functionalizations can be obtained by reacting an SBR rubber with an amino group-containing alkoxysilyl compound that has protective groups on the amino group. For example, N,N-bis(trimethylsily)aminopropylmethyldiethoxysilane can be used. Other possible substances for such functionalization are described in EP 2 703 416 A1. After deprotection (removal of the protecting group), HPR 840 is obtained.

[0070] HPR 840 is functionalized with an amino group at the other chain end. These can be primary, secondary, or tertiary amino groups, which can also be present in a ring-shaped form. Functionalization can be achieved by adding lithium amides during polymerization, as described in EP 2 703 416 A1, or by generating the amides in situ by adding n-butyllithium and amines, e.g., ring-shaped amines such as piperidine or piperazine, during polymerization.

[0071] The amino group at the other end of the chain is preferably a cyclic amino group. For this purpose, piperidine, for example, can be added in combination with n-butyllithium during polymerization. Table 5.2: 5th test series - vulcanizate tests Vulcanizate properties R9 R10 E18 E19 Shore A hardness (T= 25°C) 70,8 60,8 60,5 59,2 tan d (0°C) 0,508 0,603 0,66 0,567 tan d (70°C) 0,145 0,159 0,128 0,099 Abrasion [mm 3< ] 106 127 100 111

[0072] Compared to the vulcanizates made from R9 and R10, the E18 and E19 vulcanizates tend to have a higher loss factor tan d (0°C) (wet grip indicator) and a significantly lower loss factor tan d (70°C) (rolling resistance indicator). The rolling resistance of a tread made from E18 or E19 is therefore significantly lower than that of a tread made from R9 or R10. Furthermore, the wet grip of a tread made from E18 or E19 tends to be improved compared to that of a tread made from R9 or R10. Abrasion resistance tends to be improved.

[0073] In the 5th series of tests, it was shown that the effects are not limited to rubber compounds containing only SBR rubber and can also be achieved with higher filler quantities. conclusion

[0074] Table 6 shows a summary of the test series 1 to 5. Table 6: Summary of the test series VR1 VR2 VR3 VR3 VR4 VR4 VR5 Diene rubber SBR SBR SBR SBR SBR SBR SBR / NR resin a b d e b c b Functionalization End End Page Page End Page End Resin base α-Methylstyrene α-Methylstyrene α-Methylstyrene Methacrylate α-Methylstyrene α-Methylstyrene α-Methylstyrene average molar mass Mn [g / mol] 699 775 534 876 775 5320 775 formula Formula 1 Formula II * * Formula II Formula III Formula II Polybutadiene, terminally functionalized POLYV. EP ST-E 60 POLYV. EP ST-E 60 POLYV. EP ST-E 60 POLYV. EP ST-E 60 Ricon 603 POLYV. EP ST-E 60 POLYV. EP ST-E 60 * see WO 2018 / 191187 A1

[0075] In particular, it follows from the series of tests carried out that rubber mixtures with diene rubbers, which contain a resin functionalised on a side group or a resin functionalised at the end with a silyl protecting group in combination with a liquid polybutadiene functionalised at the end with a silyl protecting group, provide vulcanizates which have advantageous wet grip properties, low rolling resistance and at least essentially unchanged good abrasion resistance.

[0076] The invention is not limited to the specific embodiments described.

[0077] In the following, a large number of alternative mixture components are listed for the rubber mixtures E1 to E19 presented in the test series, i.e. for the exemplary embodiments of the invention, and the mixture components are explained accordingly. Diene rubber with an average molar mass Mn of more than 150,000 g / moles:

[0078] The rubber mixture according to the invention is sulfur-crosslinkable and contains at least one diene rubber.

[0079] Diene rubber refers to rubbers that are produced 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.

[0080] The diene rubber(s) is / are preferably selected from the group consisting of natural polyisoprene, synthetic polyisoprene, epoxidized polyisoprene, butadiene rubber, butadiene-isoprene rubber, solution-polymerized styrene-butadiene rubber, emulsion-polymerized styrene-butadiene rubber, styrene-isoprene rubber, liquid rubber with a molar mass Mw of greater than 20,000 g / mol, halobutyl rubber, polynorbornene, isoprene-isobutylene copolymer, ethylene-propylene-diene rubber, nitrile rubber, chloroprene rubber, acrylate rubber, fluororubber, silicone rubber, polysulfide rubber, Epichlorohydrin rubber, styrene-isoprene-butadiene terpolymer, hydrogenated acrylonitrile-butadiene rubber, hydrogenated styrene-butadiene rubber, butyl rubber (IIR) and halobutyl rubber.

[0081] If the rubber mixture is intended for a tread of a vehicle tire, the diene rubber(s) is / are preferably selected from the group consisting of natural polyisoprene (NR), synthetic polyisoprene (IR), butadiene rubber (BR), solution-polymerized styrene-butadiene rubber (SSBR) and emulsion-polymerized styrene-butadiene rubber (ESBR).

[0082] According to a preferred embodiment, the rubber mixture contains at least one natural polyisoprene in an amount of 2 phr to 100 phr, in particular 5 phr to 30 phr, particularly preferably 5 phr to 20 phr. This achieves particularly good processability of the rubber mixture. Natural polyisoprene is understood to be rubber obtained by harvesting sources such as rubber trees (Hevea brasiliensis) or non-rubber tree sources (such as guayule or dandelion (e.g. Taraxacum koksaghyz)). Natural polyisoprene (NR) is understood to mean non-synthetic polyisoprene.

[0083] According to a further advantageous embodiment, the rubber mixture contains at least one polybutadiene (butadiene rubber), preferably in an amount of 2 phr to 100 phr, in particular 5 phr to 50 phr, particularly preferably 10 phr to 25 phr. This achieves particularly good abrasion and tear properties as well as good processability with low hysteresis loss of the rubber mixture.

[0084] According to another particularly advantageous embodiment, the rubber mixture contains at least one styrene-butadiene rubber (SBR) in an amount of 2 phr to 100 phr, in particular 25 phr to 80 phr, preferably 65 phr to 85 phr. This also results in good processability with low hysteresis loss, as well as good abrasion and tear properties of the rubber mixture. The SBR is preferably an SSBR, which results in optimized properties.

[0085] According to a further particularly advantageous embodiment, the rubber mixture contains a polymer blend of the rubbers NR, BR and SBR, preferably SSBR, preferably in the amounts mentioned in each case in all possible combinations.

[0086] According to a further particularly advantageous embodiment, the rubber mixture contains at least one natural and / or synthetic polyisoprene in an amount of 5 phr to 30 phr, at least one styrene-butadiene rubber in an amount of 25 phr to 80 phr, and at least one butadiene rubber in an amount of 5 phr to 50 phr.

[0087] The natural and / or synthetic polyisoprene can be either cis-1,4-polyisoprene or 3,4-polyisoprene. The use of cis-1,4-polyisoprene with a cis-1,4 content of > 90 wt.% is preferred. The polyisoprene can be obtained by stereospecific polymerization in solution with Ziegler-Natta catalysts or using finely divided lithium alkyls. Natural rubber (NR) is cis-1,4-polyisoprene, with the cis-1,4 content being greater than 99 wt.%.

[0088] Furthermore, a mixture of one or more natural polyisoprenes with one or more synthetic polyisoprene(s) is also conceivable.

[0089] If the rubber mixture contains butadiene rubber (= BR, polybutadiene), it can be of the types known to those skilled in the art. These include, among others, the so-called high-cis and low-cis types, with polybutadiene with a cis content of greater than or equal to 90 wt.% being referred to as the high-cis type and polybutadiene with a cis content of less than 90 wt.% being referred to as the low-cis type. An example of a low-cis polybutadiene is Li-BR (lithium-catalyzed butadiene rubber) with a cis content of 20 wt.% to 50 wt. With a high-cis BR, particularly good abrasion properties and low hysteresis of the rubber mixture are achieved.

[0090] The polybutadiene(s) used can be end-group modified and / or functionalized along the polymer chains. The modifications can include hydroxyl groups, ethoxy groups, epoxy groups, siloxane groups, amino groups, aminosiloxane, carboxyl groups, phthalocyanine groups, and / or silane sulfide groups. However, other modifications known to the skilled person, also referred to as functionalizations, are also possible. Metal atoms can be a component of such functionalizations.

[0091] If at least one styrene-butadiene rubber is present in the rubber mixture, it can be either solution-polymerized styrene-butadiene rubber (SSBR) or emulsion-polymerized styrene-butadiene rubber (ESBR), although a mixture of at least one SSBR and at least one ESBR can also be used. The terms "styrene-butadiene rubber" and "styrene-butadiene copolymer" are used synonymously in the context of the present invention.

[0092] The styrene-butadiene copolymer used can be end-group modified with the modifications and functionalizations mentioned above for polybutadiene and / or functionalized along the polymer chains.

[0093] The rubbers can be used as pure rubbers or in oil-extended form. Filler:

[0094] At least one filler of any kind is included. In particular, carbon black, silica, aluminosilicates, kaolin, chalk, starch, magnesium oxide, titanium dioxide, or rubber gels, as well as fibers (such as aramid fibers, glass fibers, carbon fibers, cellulose fibers) are included in the rubber mixture, whereby the fillers can be used in combination. Furthermore, carbon nanotubes (CNTs) including discrete CNTs, so-called hollow carbon fibers (HCFs), and modified CNTs containing one or more functional groups, such as hydroxyl, carboxyl, and carbonyl groups, graphite, graphene, and carbon-silica dual-phase fillers can be provided as fillers.

[0095] Accordingly, several silicas may be present in the mixture. These silicas may be those known to those skilled in the art that are suitable as fillers for tire rubber compounds. However, it is particularly preferred if a finely divided, precipitated silica is used which has a nitrogen surface area (BET surface area) (according to DIN ISO 9277 and DIN 66132) of 35 m 2 / g to 400 m 2 / g, preferably of 35 m 2 / g to 350 m 2 / g, particularly preferably of 85 m 2 / g to 320 m 2 / g and very particularly preferably of 120 m 2 / g to 235 m 2 / g, and a CTAB surface area (according to ASTM D 3765) of 30 m 2 / g to 400 m 2 / g, preferably of 30 m 2 / g to 330 m 2 / g, particularly preferably of 80 m 2 / g to 300 m 2 / g and very particularly preferably of 115 m 2< / g to 200 m 2< / g.

[0096] Thus, silicas such as Ultrasil®< VN3 (trade name) from Evonik, silicas with a comparatively low BET surface area (such as Zeosil®< 1115 or Zeosil®< 1085 from Solvay), and highly dispersible silicas, so-called HD silicas (such as Zeosil®< 1165 MP from Solvay), can be used. Preferably, the silica has a CTAB number of more than 130 m 2 < / g.

[0097] The amount of at least one silica is in particular 5 phr to 300 phr, preferably 10 phr to 200 phr, particularly preferably 20 phr to 180 phr. In the case of different silicas, the stated amounts mean the total amount of silicas contained.

[0098] In one embodiment, the carbon black(s) has(have) an iodine number according to ASTM D 1510 (iodine adsorption number) of 30 g / kg to 250 g / kg, in particular from 30 g / kg to 180 g / kg, preferably from 40 g / kg to 180 g / kg, particularly preferably from 40 kg / g to 130 kg / g, and a DBP number according to ASTM D 2414 of 80 ml / 100 g to 200 ml / 100 g, in particular from 100 ml / 100 g to 200 ml / 100 g, preferably from 115 ml / 100 g to 200 ml / 100 g. The DBP number according to ASTM D 2414 determines the specific absorption volume of a carbon black or a light-colored filler using dibutyl phthalate.

[0099] The use of this type of carbon black in the rubber compound, especially for vehicle tires, ensures the best possible compromise between abrasion resistance and heat buildup, which in turn influences the ecologically relevant rolling resistance. It is preferred to use a single type of carbon black, but different types of carbon black can also be used in combination. Carbon black(s) are present in a total amount of up to 250 phr. Poly- or oligomer with an average molar mass Mn of less than 150,000 g / mol, which is functionalized with a filler-interacting functional group and has a glass transition temperature T g < -15°C:

[0100] Instead of the polybutadiene (BR) used in the embodiments, which is terminally functionalized with a silyl protective group, at least any desired poly- or oligomer with an average molar mass Mn (number average molar mass according to gel permeation chromatography) of less than 150,000 g / mol, which is functionalized at any point with a filler-interacting functional group and has a glass transition temperature T g < -15°C, can be used.

[0101] Filler interaction means that the poly- or oligomer interacts with the filler surface via van der Waals, dipole-dipole or electrostatic interactions or via covalent or non-covalent bonds, such as hydrogen bonds.

[0102] Preferably, the glass transition temperature T g is < -20°C, particularly preferably < -30°C. Furthermore, it is preferred if the average molar mass Mn is from 500 g / mol to 50,000 g / mol, in particular from 1,000 g / mol to 20,000 g / mol, particularly preferably from 3,000 g / mol to 15,000 g / mol.

[0103] The functionalization may involve hydroxyl groups, ethoxy groups, epoxy groups, siloxane groups, amino groups, aminosiloxane, carboxyl groups, acid anhydrides, phthalocyanine groups, and / or silane sulfide groups. However, other modifications (functionalizations) known to the expert are also possible. Metal atoms may be a component of such functionalizations.

[0104] Furthermore, it is advantageous if the poly- or oligomer mentioned contains one or more silicon atoms. It is preferably functionalized with a silyl protecting group of the formula IV: (R 1< R 2< R 3< )Si- Formula IV R 1< , R 2< , R 3< : The radicals R 1< , R 2< , R 3< are independently selected from the group consisting of linear or branched alkoxy, cycloalkoxy, alkyl, cycloalkyl, aryl, or hydroxy groups, each having 1 to 20 carbon atoms, or hydrogen.

[0105] The silyl protecting group according to formula IV can be attached to the polymer chain of the poly- or oligomer directly or via a bridge. The bridge can be formed from a saturated or unsaturated hydrocarbon radical, which may contain heteroatoms, particularly sulfur and / or nitrogen.

[0106] The functionalization may be one of those described above and have a degree of functionalization of, for example, 0.0006 mol% to 100 mol% of the monomers, in particular 0.05 mol% to 70 mol% of the monomers, preferably 0.1 mol% to 50 mol% of the monomers, wherein the functionalization may be carried out at the end or within the chain.

[0107] The polymer or oligomer functionalized with a filler-interacting group can be present in particular in amounts of 5 phr to 200 phr, preferably 10 phr to 150 phr, particularly preferably 10 phr to 100 phr.

[0108] Furthermore, unfunctionalized polymers or oligomers or a combination of functionalized and unfunctionalized polymers or oligomers can be mixed into the mixture. The total amount of polymers or oligomers mixed in is from 2 phr to 200 phr, in particular from 5 phr to 150 phr, preferably from 10 phr to 100 phr. Furthermore, combinations of functionalized polymers or oligomers can be used. In particular, combinations of end-group and side-group functionalized oligomers or polymers can be used.

[0109] Als Poly- oder Oligomer kommen hier alle Polymere mit Tg <-15°C infrage, somit auch Polyolefine wie Poly(vinylidene chloride), Polyethylen, Poly(vinylidene fluoride), , Polyacrylate, Poly(decyl methacrylate), Poly(dodecyl methacrylate), Poly(isodecyl methacrylate), Poly(octyl methacrylate) Polypropylen, , Poly(1-butene), Poly(1-octene), Poly(1-pentene),, Poly(isobutene), Poly(1-methyl-1-butenylene), Poly(caprolactone), Poly(1,4-butane sebacate), Poly(ethylene adipate), Poly(3-hexoxypropylene oxide), Poly(dipropyl fumarate), Poly(ethylene glycol), Poly(propylene glycol), Poly(trimethylene glycol), Polyacetal, Poly(vinyl ether), Poly(vinyl ethyl ketone), Poly(butyl vinyl thioether), sowie die o.g.Rubbers consisting of polyisoprene, epoxidized polyisoprene, butadiene rubber, butadiene-isoprene rubber, styrene-butadiene rubber, styrene-isoprene rubber, halobutyl rubber, polynorbornene, isoprene-isobutylene copolymer, ethylene-propylene-diene rubber, nitrile rubber, chloroprene rubber, acrylate rubber, polycyclopentene rubber, fluororubber, silicone rubber, polysulfide rubber, epichlorohydrin rubber, styrene-isoprene-butadiene terpolymer, hydrogenated acrylonitrile-butadiene rubber, hydrogenated styrene-butadiene rubber, farnesene and liquid rubbers with a molar mass Mw of greater than 20000 g / mol.

[0110] Preferably, the poly- or oligomer(s) is / are selected from the group polyethylene, polypropylene, natural polyisoprene, synthetic polyisoprene, epoxidized polyisoprene, butadiene rubber, butadiene-isoprene rubber, solution-polymerized styrene-butadiene rubber, emulsion-polymerized styrene-butadiene rubber, styrene-isoprene rubber, liquid rubbers with a molar mass Mw of greater than 20,000 g / mol, halobutyl rubber, polynorbornene, isoprene-isobutylene copolymer, ethylene-propylene-diene rubber, nitrile rubber, chloroprene rubber, acrylate rubber, fluororubber, silicone rubber, polysulfide rubber, Epichlorohydrin rubber, styrene-isoprene-butadiene terpolymer, hydrogenated acrylonitrile-butadiene rubber, hydrogenated styrene-butadiene rubber and farnesene.

[0111] Furthermore, combinations of the aforementioned oligo- or polymers can be used. Poly- or oligomer with an average molar mass Mn of less than 150,000 g / mol, which is functionalized with a filler-interacting functional group and has a glass transition temperature T g > -15°C:

[0112] The resin used in the embodiments, which is terminally functionalized with a silyl protective group, is any desired poly- or oligomer with a glass transition temperature T g > -15°C, in particular > -10°C, which is functionalized at any desired position with a filler-interacting functional group.

[0113] The molar mass (Mn) is in particular 200 g / mol to 150,000 g / mol, preferably 200 g / mol to 50,000 g / mol, particularly preferably 200 g / mol to 30,000 g / mol. The glass transition temperature (Tg) is in particular below 200°C, preferably below 180°C, and particularly preferably below 160°C.

[0114] Furthermore, combinations of oligo- or polymers with different molar masses can be used.

[0115] The functionalization may involve hydroxyl groups, ethoxy groups, epoxy groups, siloxane groups, amino groups, aminosiloxane, carboxyl groups, acid anhydrides, phthalocyanine groups, and / or silane sulfide groups. However, other modifications (functionalizations) known to the expert are also possible. Metal atoms may be a component of such functionalizations.

[0116] Preferably, this poly- or oligomer is also functionalized with the silyl protecting group of the aforementioned formula IV, as described in WO 2015 / 153055 for dicyclopentadienes (DCPD). Alternatively, it is preferred if it is functionalized with a silyl protecting group according to formula V. - [Z k -X n -R 4< -(CH 2 ) m -Si(R 5< ) p ] q Formula V

[0117] In Formula V Z represents an aromatic or aliphatic group, optionally with one or more heteroatom(s), X represents a linker containing sulfur and / or oxygen and / or nitrogen and / or a carbonyl group, R 4 represents one or more aliphatic group(s) having 1 to 18 carbon atoms and / or a linking group having at least one heteroatom, in particular with oxygen, nitrogen or sulfur, R 5 represents a branched or unbranched alkoxy, aryloxy, alkyl or aryl group having 1 to 18 carbon atoms, hydrogen or a hydroxy group, where at least one R 5 represents an alkoxy or aryloxy group having 1 to 18 carbon atoms, a hydrogen atom or a hydroxy group, where R 5 can be the same or different within the molecule, q represents an integer ≥ 1, k represents 0 or 1, n represents an integer between 1 and 10, m represents an integer between 0 and 10 and p for 1, 2 or 3.

[0118] The functionalization can be one of those described above and have a degree of functionalization of, for example, 0.0006 mol% to 100 mol% of the monomers, 0.05 mol% to 70 mol% of the monomers, preferably 0.1 mol% to 50 mol% of the monomers, wherein the functionalization can occur at the end or within the chain. The polymer or oligomer functionalized with a filler-interacting group can be used in amounts of 5 phr to 200 phr, in particular from 10 phr to 150 phr, particularly preferably from 10 phr to 100 phr.

[0119] Furthermore, unfunctionalized polymers or oligomers can be mixed into the mixture, or a combination of functionalized and unfunctionalized polymers or oligomers can be mixed into the mixture. The total amount of polymers or oligomers mixed in is 2 phr to 200 phr, 5 to 150 phr, or 10 to 100 phr.

[0120] The preferably used oligomer or polymer is based in particular on the polymerization or copolymerization of two or more unsaturated aliphatic monomers, unsaturated aromatic monomers, terpenes, terpene phenols, rosin acids, rosin, unsaturated cycloaromatic monomers, unsaturated cycloaliphatic monomers, unsaturated fatty acids, methacrylates, and / or vinylaromatic monomers, or a mixture of aliphatic and aromatic monomers. The aliphatic monomer can be selected from C 5 1,3-pentadiene, benzofuran (coumarone), indene, indane, as described in WO2018118855A1, and dicyclopentadiene. The aromatic monomers and / or vinylaromatic monomers can be selected, for example, from styrene, vinyltoluene, alpha-methylstyrene, and diisopropylbenzene.

[0121] The monomers of terpenes can be mono- and / or bicyclic terpenes.

[0122] The oligo- or polymer can further be selected from the group polyolefins, polyesters, polyethers, polythioethers, polyketones, polyphthalates, polyterephthalates, polyacrylamides, polylactates, polycarvonates, polyacetates, polyketones, polymethacrylates, polyacrylates, polymethacrylonitriles and polyacrylonitriles, polyamides as oligo- or polymers.

[0123] In particular, these include alpha-methylstyrene, styrene, vinyltoluene, diisopropylbenzene, 1,3-pentadiene, benzofuran (coumarone), indene, indane, dicyclopentadiene, terpenes, ethyl vinyl acetate, ethyl butyl acetate and styrene block copolymers.

[0124] Furthermore, combinations of functionalized polymers or oligomers can be used. In particular, combinations of end-group and side-group functionalized oligomers or polymers can be used. Silane:

[0125] Silanes are optionally used in the mixture according to the invention, in particular when the selection of the said poly- or oligomers with Tg <-15°C or Tg >-15°C does not yet allow optimal crosslinking to the diene rubber and thus optimal bonding of the diene rubber to the filler.

[0126] A coupling agent in the form of a silane or an organosilicon compound is preferably present in the rubber mixture. A single silane or various silanes can be used in combination. Suitable silanes are listed, for example, in WO 2018 / 191187 A1, paragraph

[0094] .

[0127] Silane coupling reagents can be used as adhesion promoters for inorganic materials, for example glass beads, glass fragments, glass surfaces, glass fibers, for oxidic fillers, preferably silicas, and for organic polymers, for example thermosets, thermoplastics or elastomers, or as crosslinking agents and surface modifiers for oxidic surfaces.

[0128] The silane coupling agents react with the surface silanol groups of the silica or other polar groups during the mixing of the rubber or rubber compound (in situ) or even before the addition of the filler to the rubber in the sense of a pretreatment (premodification).

[0129] All silane coupling agents known to the skilled person for use in rubber mixtures can be used as silane coupling agents. Such coupling agents known from the prior art are bifunctional organosilanes that possess at least one alkoxy, cycloalkoxy, or phenoxy group as a leaving group on the silicon atom and that have, as another functionality, a group that, optionally after cleavage, can enter into a chemical reaction with the double bonds of the polymer. The latter group can be, for example, one of the following chemical groups: -SCN, -SH, -NH 2 , or -Sx- (where x = 2 to 8).

[0130] For example, 3-mercaptopropyltriethoxysilane, 3-thiocyanatopropyltrimethoxysilane, or 3,3'-bis(triethoxysilylpropyl) polysulfides with 2 to 8 sulfur atoms, such as 3,3'-bis(triethoxysilylpropyl)tetrasulfide (TESPT), the corresponding disulfide (TESPD), or mixtures of sulfides with 1 to 8 sulfur atoms with varying contents of the various sulfides, can be used as silane coupling agents. TESPT can also be added, for example, as a mixture with carbon black (trade name X50S ®< from Evonik). Preferably, a silane mixture is used which contains 40 wt.% to 100 wt.% disulfides, particularly preferably 55 wt.% to 85 wt.% disulfides and very particularly preferably 60 wt.% to 80 wt.% disulfides.

[0131] Blocked mercaptosilanes, such as those known from WO 99 / 09036, can also be used as silane coupling agents. Silanes such as those described in WO 2008 / 083241 A1, WO 2008 / 083242 A1, WO 2008 / 083243 A1, and WO 2008 / 083244 A1 can also be used. Examples of suitable silanes include those sold under the name NXT in various versions by Momentive, USA, or those sold under the name VP Si 363 ® by Evonik Industries. The amount of silane coupling agent is preferably 0.1 to 20 phf, particularly preferably 1 to 15 phf.

[0132] Description of the hydrolyzable groups of a silane: (R1)oSi-R2 where o is 1, 2 or 3.

[0133] The radicals R1 are identical or different and are selected from the group consisting of alkoxy groups having 1 to 10 carbon atoms, cycloalkoxy groups having 4 to 10 carbon atoms, phenoxy groups, aryl groups having 6 to 20 carbon atoms, alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, aralkyl groups having 7 to 20 carbon atoms, alkyl polyether group -O-(R3-O)r-R5 (wherein R3 are identical or different and are branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic / aromatic divalent C1-C30 hydrocarbon group, preferably -CH2-CH2-, and where r is an integer from 1 to 30, preferably 3 to 10, and R5 is unsubstituted or substituted, branched or unbranched, monovalent alkyl, alkenyl, aryl or aralkyl groups, preferably -C 13 H 27 alkyl group or halides).

[0134] Two R1 can form a cyclic dialkoxy group with 2 to 10 carbon atoms, or two R1 from each other molecule can represent a bridging oxygen atom, with one R1 per molecule being an alkoxy or halide group.

[0135] The radical R2 stands for linear or branched alkyl groups with 1 to 20 carbon atoms, cycloalkyl groups with 4 to 12 carbon atoms, aryl groups with 6 to 20 carbon atoms, aralkyl groups with 7 to 20 carbon atoms, alkenyl groups with 2 to 20 carbon atoms or alkynyl groups with 2 to 20 carbon atoms.

[0136] The silane can be applied to a carrier, for example, wax, polymer, or carbon black, and added to the rubber mixture in this form. The silane according to the invention can be applied to a silica, whereby the bonding can be physical or chemical. plasticizers / Process aids:

[0137] Processing aids are oils and other viscosity-reducing substances. These processing aids can be, for example, plasticizer oils or plasticizer resins.

[0138] Examples of plasticizers include 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 oils (RTL), or biomass-to-liquid oils (BTL), or factice, or plasticizer resins, or liquid polymers (such as liquid BR) whose average molar mass (determined by GPC = gel permeation chromatography, based on BS ISO 11344:2004) is between 500 g / mol and 20,000 g / mol. If liquid polymers are used as plasticizers in the rubber mixture according to the invention, they are not included as rubber in the calculation of the composition of the polymer matrix.When using mineral oil, it is preferably selected from the group consisting of DAE (Distilled Aromatic Extracts) and / or RAE (Residual Aromatic Extract) and / or TDAE (Treated Distilled Aromatic Extracts) and / or MES (Mild Extracted Solvents) and / or naphthenic oils.

[0139] It is clear to those skilled in the art that hydrocarbon resins are polymers composed of monomers, whereby the hydrocarbon resin is formally composed of derivatives of the monomers due to the linkage of the monomers to one another. However, these hydrocarbon resins are not considered rubbers within the scope of the present invention. The term "hydrocarbon resins" within the scope of the present application encompasses resins that contain carbon atoms and hydrogen atoms and may optionally contain heteroatoms, such as, in particular, oxygen atoms. The hydrocarbon resin can be a homopolymer or a copolymer. In the present application, a homopolymer is understood to mean a polymer that, according to Römpp Online Version 3.28, "is formed from monomers of only one type."

[0140] The monomers may be any monomers of hydrocarbon resins known to the person skilled in the art, such as aliphatic C5 monomers, other unsaturated compounds which can be cationically polymerized, containing aromatics and / or terpenes, terpenephenols and / or alkenes and / or cycloalkenes.

[0141] In a preferred embodiment of the invention, the hydrocarbon resin is selected from the group consisting of aliphatic C5 resins and hydrocarbon resins of alpha-methylstyrene and styrene.

[0142] Preferably, the hydrocarbon resin has a softening point according to ASTM E 28 (ring and ball) of 10°C to 180°C, in particular of 60°C to 150°C, particularly preferably of 80°C to 99°C.

[0143] Furthermore, the hydrocarbon resin preferably has a molar mass Mw of 500 g / mol to 4000 g / mol, preferably of 1300 g / mol to 2500 g / mol. Crosslinking agent (vulcanizing agent):

[0144] As crosslinking agent, preferably at least one sulfur or at least one sulfur donor and peroxidic crosslinkers, for example organic peroxides such as dicumyl peroxide, di-(2,4-dichlorobenzoyl) peroxide, tert-butyl peroxybenzoate, 1,1-di-(tert-butylperoxy)-3,3,5-trimethylcyclohexane, butyl 4,4-di-(tert-butylperoxy)valerate, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, di-(2-tert-butylperoxyisopropyl)benzene or tert-butylcumyl peroxide or a combination thereof are used. As further alternatives, the crosslinking agents mentioned in WO 2018 / 191187 A1, paragraph

[0094] , can be used. Accelerators and activators:

[0145] The accelerators and activators are optional mixture components; they are particularly components of a sulfur-accelerator crosslinking system and are therefore preferably used in combination with sulfur or a sulfur donor. Possible accelerators can be found, for example, in WO 2018 / 191187 A1, paragraph

[0094] .

[0146] Sulfur or sulfur donors as well as one or more accelerators are added to the rubber mixture in the specified quantities in the final mixing step.

[0147] The accelerator is preferably selected from the group consisting of thiazole accelerators and / or mercapto accelerators and / or sulfenamide accelerators and / or thiocarbamate accelerators and / or thiuram accelerators and / or thiophosphate accelerators and / or thiourea accelerators and / or xanthate accelerators and / or guanidine accelerators.

[0148] Examples are N-cyclohexyl-2-benzothiazolesufenamide (CBS), N,N-dicyclohexylbenzothiazole-2-sulfenamide (DCBS), benzothiazyl-2-sulfenmorpholide (MBS), N-tert-butyl-2-benzothiazylsulfenamide (TBBS), diphenylguanidine (DPG)

[0149] Other network-forming systems, such as those available under the trade names Vulkuren ®<, Duralink ®< or Perkalink ®<, or network-forming systems as described in WO 2010 / 049261 A2, can also be used in the rubber mixture. Other optional components:

[0150] a) Anti-aging agents: e.g., N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-ditolyl-p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ). b) Activators: e.g., fatty acids (e.g., stearic acid) and / or zinc oxide (ZnO granules or powder). Conventionally used zinc oxide generally has a BET surface area of ​​less than 10 m² / g. However, so-called nanozinc oxide with a BET surface area of ​​10 m² / g to 60 m² / g can also be used. c) Waxes d) Resins, in particular tackifier resins e) Mastication aids, such as 2,2'-dibenzamidodiphenyl disulfide (DBD) and f) Processing aids, such as fatty acid salts (e.g. zinc soaps), fatty acid esters and their derivatives as well as lipids and phospholipids, in particular lecithins, such as soy lecithin. g) Reinforcing resins, such asLignin, phenol-formaldehyde resins with hardeners, and polymer resins h) Cobalt salts and others. To improve rubber-to-metal adhesion, it has long been known to use cobalt salts and / or a resorcinol-formaldehyde-silica system or a resorcinol-formaldehyde system as additives for rubberizing compounds. Precondensates of resorcinol resins can also be used. Rubberizing compounds with cobalt salts and a resorcinol-formaldehyde-silica system are known, for example, from KGK Kautschuk Gummi Kunststoffe No. 5 / 99, pp. 322-328, from GAK 8 / 1995, p. 536, and from EP-A-1 260 384. i) Reinforcing resins The reinforcing resins can be based, for example, on a methylene donor, e.g. hexamethoxymethylmelamine (HMMM) or hexamethylenetetramine (HMT), and a methylene acceptor, e.g. resorcinol, phenol or a resorcinol, phenol or acetone derivative.For example, methylene acceptors based on a resorcinol-formaldehyde novolac resin, a resorcinol-formaldehyde-styrene novolac resin, a phenol-formaldehyde novolac resin, for example Alnovol®< types, a phenol-formaldehyde-styrene novolac resin, a phenol-formaldehyde-urethane novolac resin or an acetone novolac resin can be used. The reinforcing resins preferably contain an unbound resorcinol content of less than 0.1% and an unbound phenol content of less than 1%. The reinforcing resins can also be based exclusively on a methylene donor, e.g. hexamethoxymethylmelamine (HMMM) or hexamethylenetetramine (HMT). j) Cobalt is preferably present as part of a steel cord adhesive system based on organic cobalt salts and reinforcing resins and more than 2.5 phr of sulfur. The organic cobalt salts are usually used in amounts of 0.2 to 2 phr. Examples of cobalt salts include:Cobalt stearate, borate, borate alkanoate, naphthenate, rhodium, octoate, adipate, etc. can be used.

Claims

1. Crosslinkable rubber mixture comprising: a) a diene rubber having an average molar mass Mn of more than 150 000 g / mol, b) a filler, c) a polymer or oligomer having an average molar mass Mn of less than 150 000 g / mol, which has a filler-interactive functional group and a glass transition temperature Tg < -15°C, d) a polymer or oligomer having an average molar mass Mn of less than 150 000 g / mol, which has a filler-interactive functional group and a glass transition temperature Tg > -15°C, wherein the temperature differential ΔTg ascertained between the glass transition temperature Tg of the polymer or oligomer of feature c) and the glass transition temperature Tg of the polymer or oligomer of feature d) is at least 5°C, wherein the filler-interactive functional groups bring about an interaction of the polymer or oligomer with the filler surface via van der Waals, dipole-dipole or electrostatic interactions or via covalent or non-covalent bonds, for example hydrogen bonds.

2. Rubber mixture according to Claim 1, characterized in that it contains silica and / or carbon black as filler.

3. Rubber mixture according to Claim 1 or 2, characterized in that the polymer or oligomer of feature c) is a diene-based polymer or oligomer.

4. Rubber mixture according to any of Claims 1 to 3, characterized in that the polymer or oligomer of feature c) has a glass transition temperature Tg of < -20°C, especially of < -30°C.

5. Rubber mixture according to any of Claims 1 to 4, characterized in that the polymer or oligomer of feature c) is an average molar mass Mn (number-average molar mass by gel permeation chromatography) of 500 g / mol to 50 000 g / mol, especially of 1000 g / mol to 20 000 g / mol, more preferably of 3000 g / mol to 15 000 g / mol.

6. Rubber mixture according to any of Claims 1 to 5, characterized in that the polymer or oligomer of feature c) has been functionalized with a silyl protecting group.

7. Rubber mixture according to Claims 1 to 6, characterized in that the polymer or oligomer of feature c) is a polybutadiene functionalized with a filler-interactive functional group.

8. Rubber mixture according to any of Claims 1 to 7, characterized in that the polymer or oligomer of feature c) and / or the polymer or oligomer of feature d) has been functionalized with a silyl protecting group of the formula IV:         (R1R2R3)Si-     Formula IV where R1, R2, R3 are independently selected from the group of linear or branched alkoxy, cycloalkoxy, alkyl, cycloalkyl, aryl or hydroxyl groups, in each case having 1 to 20 carbon atoms, or hydrogen and where the silyl protecting group of formula IV is attached directly or via a bridge to the polymer chain of the polymer or oligomer and where the bridge is formed from a saturated or unsaturated hydrocarbyl radical that may contain heteroatoms, especially sulfur and / or nitrogen.

9. Rubber mixture according to any of Claims 1 to 8, characterized in that the polymer or oligomer of feature d) has been functionalized with a silyl protecting group of the formula V:         -[Zk-Xn-R4-(CH2)m-Si(R5)p]q     Formula V where - Z is an aromatic or aliphatic group, optionally having one or more heteroatom(s), - X is a linker containing sulfur and / or oxygen and / or nitrogen and / or a carbonyl group, - R4 is one or more aliphatic groups having 1 to 18 carbon atoms and / or a connecting group to at least one heteroatom, especially to oxygen, nitrogen or sulfur, - R5 is a branched or branched alkoxy, aryloxy, alkyl or aryl group having 1 to 18 carbon atoms, hydrogen or a hydroxyl group, where at least one R5 is an alkoxy or aryloxy group having 1 to 18 carbon atoms, a hydrogen atom or a hydroxyl group, where R5 is the same or different within the molecule, - q is an integer ≥ 1, - k is 0 or 1, - n is an integer from 1 to 10, - m is an integer from 0 to 10 and - p is 1, 2 or 3.

10. Rubber mixture according to any of Claims 1 to 9, characterized in that the polymer or oligomer of feature d) is a resin based on unsaturated aliphatic monomers, unsaturated aromatic monomers, terpenes, rosin, unsaturated cycloaromatic monomers, unsaturated cycloaliphatic monomers, unsaturated fatty acids, methacrylates and / or vinylaromatic monomers.

11. Rubber mixture according to any of Claims 1 to 10, characterized in that the polymer or oligomer of feature d) has a molar mass (Mn) of 200 g / mol to 150 000 g / mol, preferably of 200 g / mol to 50 000 g / mol, more preferably of 200 g / mol to 30 000 g / mol.

12. Rubber mixture according to any of Claims 1 to 11, characterized in that the polymer or oligomer of feature c) and the polymer or oligomer of feature d) are present in a ratio of 1:50 to 50:1, especially of 1:10 to 10:1, preferably of 1:5 to 5:1, and more preferably of 1:3 to 3:1.

13. Rubber mixture according to any of Claims 1 to 12, characterized in that the temperature differential ΔTg ascertained between the glass transition temperature Tg of the polymer or oligomer of feature c) and the glass transition temperature Tg of the polymer or oligomer of feature d) is at least 10°C.

14. Rubber mixture according to any of Claims 1 to 13, characterized in that it contains at least one silane coupling agent.

15. Pneumatic vehicle tyre including at least one tyre component consisting of rubber, especially a tread, that has been manufactured at least partly from a rubber mixture according to any of Claims 1 to 13.