Polyisobutene derivatives as an additive in rubbers

Abstract

The present invention relates to the use of sulfurous polyisobutene derivatives as additives in rubbers, in particular for the dispersion and compatibilization of additives in rubbers for vehicle tires, as vulcanization accelerators and for improving the properties of tires.

Description

231396 1 Polyisobutene derivatives as additives in rubbers Description The present invention relates to the use of sulfur-containing polyisobutene derivatives as additives in rubbers, particularly for dispersing and compatibilizing additives in rubbers for vehicle tires, as vulcanization accelerators, and for improving tire properties. Modern vehicle tires are subject to increased demands on their properties, not least from a sustainability perspective, particularly with regard to low rolling resistance to reduce fuel consumption and associated emissions, and high abrasion resistance to reduce the emission of tire debris, for example in the form of microplastics, into the environment and to increase tire service life without simultaneously impairing tire adhesion to the surface under various conditions (e.g., temperature, weather conditions, road conditions).To improve these properties, vehicle tires can contain various filler materials and vulcanization accelerators in the rubber compounds. These filler materials are often inorganic materials such as carbon black, silicates, or zinc oxide, while the rubbers themselves are non-polar polymers. Therefore, the miscibility and compatibility of these components is often poor due to their different polarities. Other additives, such as vulcanization accelerators and activators, antioxidants, and plasticizers, require uniform distribution within the rubber to ensure their effect is evenly distributed. Therefore, there is a need for additives that allow filler materials such as carbon black, silicates, or zinc oxide, as well as the other additives mentioned, to be better incorporated into rubber and to perform their functions in the rubber or rubber mixture.during their production, for example as an antioxidant, activator or plasticizer. WO 2022 / 223345 A1 describes the use of polyisobutene derivatives containing at least one sulfide or mercapto group for compatibilization and / or as a dispersant for sulfur in rubbers and as a vulcanizing agent. The dispersion of additives other than sulfur is not disclosed. Furthermore, the influence on the properties of the finished tire is not recognized. The object was achieved by the use of reaction products of polyisobutene with a molecular weight Mn of 104 to 100,000 g / mol, preferably from 104 to 10,000 g / mol, particularly preferably from 156 to 5,000 g / mol and very particularly preferably from 500 to 2,500 g / mol, preferably highly reactive polyisobutene. 231396 2 elemental sulfur and their hydrolysis products to improve at least one of the following properties: dispersion coefficient, particle size, wet grip, abrasion resistance, rolling resistance of rubber-containing tires or to accelerate vulcanization in rubber compounds, or to capture alcohols released during tire production. Due to its production, the polyisobutene used is a mixture of double bond isomers, which determine the properties and especially the chemical reactivity of the polyisobutene. The most important are Isomers with alpha double bonds, as well as Isomers with beta-double bonds, in which the residue R 1represents the remainder of the polyisobutene without the substructure shown, i.e., the polyisobutene shortened by one isobutene unit with a molecular weight Mn of 104 to 100,000 g / mol, preferably of 104 to 10,000 g / mol, particularly preferably of 156 to 5,000 g / mol, and very particularly preferably of 500 to 2,500 g / mol, which was used as the starting material. Furthermore, further isomers are conceivable, as shown, for example, in WO 2023 / 152258, which, however, play only a minor role according to the invention. 231396 3According to the invention, the polyisobutene has a number-average molecular weight Mn of 104 to 100,000 g / mol, preferably from 104 to 10,000 g / mol, particularly preferably from 156 to 5,000 g / mol, and very particularly preferably from 500 to 2,500 g / mol. The molecular weight is determined by gel permeation chromatography using polystyrene as standard. In a preferred embodiment of the invention, the polyisobutene has a number-average molecular weight Mn of 300 to 10,000 g / mol, preferably from 500 to 5,000, particularly preferably from 700 to 2,500, and an alpha-double bond content of at least 70%, preferably at least 75%, particularly preferably at least 80%, very particularly preferably at least 85%, and in particular at least 90%. Such polyisobutene is also referred to as low molecular weight and highly reactive polyisobutene.The content of beta-double bonds can be up to 25%, preferably up to 20, particularly preferably up to 15, most particularly preferably up to 10 and in particular up to 5%.The content of isomers other than those with alpha or beta double bonds is usually not more than 5%.The content of isomers is determined using the. 1 H-NMR spectroscopy, with the sensitivity being determined by the frequency of the measuring device. 1H-NMR spectroscopy is carried out at 700 MHz at 25 °C. The isomers are particularly preferably identified by the method as described in Guo et al., Journal of Polymer Science, Part A: Polymer Chemistry, 2013, 51, 4200-4212. In a further preferred embodiment, the polyisobutene used has a number-average molecular weight Mn of more than 10,000 up to 100,000 g / mol, preferably from 11,000 to 90,000, particularly preferably from 12,000 to 80,000, very particularly preferably from 13,000 to 75,000 and in particular from 14,000 to 70,000 and an alpha double bond content of at least 20 to 60%, preferably at least 25 to 45%, particularly preferably at least 30 to 40%. Such a polyisobutene is also called medium molecular weight polyisobutene.Conceivable, although less preferred, is the use of high-molecular-weight polyisobutene with a number-average molecular weight of more than 100,000 up to 5,000,000 g / mol, which generally has an alpha-double bond content of no more than 50%, preferably no more than 40%, and particularly preferably no more than 30%. In a further embodiment, the polymer used, instead of polyisobutene, is a product from the polymerization of 1- and / or 2-butene, particularly 1-butene or a butene-containing polymer. 231396 4 Monomer mixture. In this case, the compounds are not polyisobutene derivatives, but polybutene derivatives. In a further embodiment, the remaining polymer used, instead of polyisobutene, is a product from the polymerization of propene or a propene-containing monomer mixture. In this case, the compounds are not polyisobutene derivatives, but polypropene derivatives. The highly reactive polyisobutene is reacted with elemental sulfur under reaction conditions such that the reactive double bond of the polyisobutene reacts with the sulfur. Exemplary reaction conditions are described in WO 2009 / 010441 A2, see Preparation Example (B3) therein.Polyisobutene is preferably reacted with 3 to 10 equivalents of elemental sulfur, preferably predominantly in the form of S8 molecules, per alpha double bond in the polyisobutene for 0.5 to 5 hours at 150 to 260, preferably 170 to 250 °C, preferably under inert gas at normal or optionally superatmospheric pressure. According to WO 2009 / 010441 A2, the two heterocycles are formed as the main components in the reaction mixture. In a preferred embodiment, the reaction products usable according to the invention contain at least one of these two heterocyclic products, particularly preferably a mixture of these two heterocyclic products. Thiol-bearing polyisobutene derivatives can be obtained from the reaction products by hydrolysis, which can also be used for the inventive application. 231396 5 These reaction products can be, for example, compounds of the following formulae: 1 R 1 R S 231396 6 S 1 R 1 R The invention is explained in more detail below: Rubber. In vehicle tire compounds, especially for the treads, mixtures of butyl rubber with diene elastomers and other components are used, for example. Such mixtures are described, for example, in WO2019 / 199839 A1, paragraph

[0008] until

[0070] , which is incorporated by reference into the present disclosure. In the context of this document, rubbers are understood to mean diene elastomers, i.e. homo- and copolymers of diene monomers, preferably natural rubber, polybutadienes, styrene-butadiene copolymers and polyisoprene, and mixtures thereof, for example mixtures of natural rubber and styrene-butadiene copolymers, of natural rubber and polybutadienes, or natural rubber and polyisoprenes. The diene elastomers generally have a glass transition temperature Tg of -75 to 0 °C. Polybutadienes are polymers of 1,3-dienes, preferably buta-1,3-diene, with a cis-1,4-linkage of at least 90%, preferably at least 95%. Other comonomers can be polymerized in small amounts. 231396 7 The elastomer used is preferably polybutadiene with more than 90% cis-1,4-linkages, which is obtained by known catalytic processes with transition metal compounds, as described, for example, in French patent application FR-A-1436607. Examples of suitable conjugated dienes are, in particular, 1,3-butadiene, isoprene, and 2,3-dimethyl-1,3-butadiene. Aromatic vinyl compounds can also be copolymerized; suitable aromatic vinyl compounds are, in particular, styrene, o-, m-, and p-methylstyrene, or the commercially available "vinyltoluene" mixture. Styrene-butadiene copolymers Typical styrene-butadiene copolymers have a styrene content of 5 to 60, preferably 20 to 50 wt.%, with the remaining comonomers being predominantly 1,3-butadiene. The content of 1,2-units is typically 4 to 80 mol%, and that of cis-1,4-units is more than 80 mol%. Styrene-butadiene-isoprene terpolymers are also conceivable.Polyisoprene refers to homo- and copolymers of isoprene, which can be of natural or, preferably, synthetic origin. In these, the proportion of cis-1,4-units is at least 90 mol%, preferably at least 98 mol%. Butyl rubber refers to copolymers of 85 to 99.5 mol%, preferably 90 to 99.5, particularly preferably 95 to 99.5 mol%, of C4-C7 isoolefins with 0.5 to 15 mol%, preferably 0.5 to 10, particularly preferably 0.5 to 5 mol%, of C4-C14 conjugated dienes. The preferred isoolefin is isobutene; preferred conjugated dienes are 1,3-butadiene and isoprene, particularly preferably isoprene. The butyl rubber has a viscosity-average molecular weight of 100,000 to 1,500,000, preferably 250,000 to 800,000. The starting materials for the synthetic rubbers, preferably 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, styrene and / or isobutene, particularly preferably 1,3-butadiene, isoprene and / or isobutene, can be at least partially,. 231396 8 preferably originate entirely from renewable sources. Their proportion of the total monomers used, measured according to ASTM D 6866 (see below), is advantageously at least 1% by weight, preferably at least 2% by weight, more preferably at least 10% by weight, most preferably at least 25% by weight, and in particular at least 50% by weight. The proportion of monomers from renewable sources can be up to 100% by weight, preferably up to 95% by weight, more preferably up to 90% by weight, most preferably up to 85% by weight, and in particular up to 80% by weight. Plasticizers Plasticizers (process oils) improve the processability of the composition; these are usually esters of aliphatic acids, for example fatty acid esters and fatty acid glycerides, preferably naturally occurring oils such as sunflower oil or rapeseed oil, or hydrocarbons such as paraffinic oils, aromatic oils, naphthenic petroleum oils, and polybutene oils.Also suitable as plasticizers are resins known as tackifiers for adhesives and paints. These are preferably copolymers of C5 fractions of naphtha or steam cracker discharges with vinyl aromatics, particularly copolymers of 1,3-butadiene, 1-butene, 2-butenes, 1,2-butadiene, 3-methyl-1-butene, 1,4-pentadiene, 1-pentene, 2-methyl-1-butene, 2-pentenes, isoprene, cyclopentadiene (which can also be present as a dicyclopentadiene dimer), piperylene, cyclopentene, 1-methylcyclopentene, 1-hexene, methylcyclopentadienes, or cyclohexene. In particular, these are copolymers of cyclopentadiene and / or dicyclopentadiene with vinyl aromatics, especially styrene, α-methylstyrene, o-, m- or p-methylstyrene or divinylstyrene. These vinyl aromatics are components of the C9 fractions of naphtha or steam cracker discharges.Preferred resins as plasticizers are cyclopentadiene and / or dicyclopentadiene copolymers, cyclopentadiene and / or dicyclopentadiene-styrene copolymers, polylimonene, limonene-styrene copolymers, limonene-cyclopentadiene and / or dicyclopentadiene copolymers, C5 fraction-styrene copolymers, and C5 fraction-C9 fraction copolymers. Fillers: Examples of fillers are calcium carbonate, clays, mica, silica, silicates, talc, bentonite, titanium dioxide, aluminum oxide, zinc oxide, and carbon black, preferably zinc oxide, silicates, and carbon black. Typical particle sizes are in the range of 0.0001 to 100 µm. 231396 9Silicates are understood here to be derivatives of silicic acid, including in the form of their calcium or aluminum compounds. The silicates can be obtained from solution or pyrogenically and can be colloidal or precipitated. Highly dispersible silicates are preferred. The BET surface area is usually less than 450 m 2 / g, preferably 30 to 400, particularly preferably from 100 to 250 m 2 / g and preferably from 130 to 220 m 2 / g, a CTAB surface of 100 to 250 m 2 / g and preferably from 150 to 200 m 2 / g, an oil uptake of DBP of 150 to 250 ml / 100 g and an average projection area of ​​the aggregates of more than 8500 nm 2 and preferably 9000 to 11000 nm 2 before use and from 7000 to 8400 nm 2after thermomechanical mixing with an elastomer. The specific silica selected can be used alone or in the presence of other fillers, such as carbon black or another conventional silica. A particularly suitable silica is, for example, the silica obtained by the process described in European patent application EP-A-157703. The BET surface area, the CTAB surface area, and the oil absorption are measured according to the methods described in European patent application EP-A-157703. The mean projected area of ​​the silica is determined according to the method described in DE 69206445 T2, page 8, last paragraph to page 9, first paragraph.Antioxidants: Antioxidants act against oxidative degradation; in particular, p-phenylenediamines are worth mentioning, for example N,N'-alkyl- or aryl-disubstituted p-phenylenediamines; N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine is particularly preferred. Hardeners, crosslinkers, activators: The rubber compositions are reacted with at least one hardener and at least one crosslinker, which are known to those skilled in the art. Examples include organic peroxides and polyamines. In particular, sulfur is used as a vulcanizing agent. 231396 10 Amines, diamines, guanidines, thioureas, thiatols, thiram, sulfenamides, sulfenimides, thiocarbamates and xanthates are used as activators for the vulcanization process. N-cyclohexylbenzothiazole-2-sulfenamide (CBS) is particularly suitable. Sulfur, metal oxides, fatty acids, especially stearic acid, and especially organosilane crosslinkers (see below under silane coupling agents) can be used as crosslinkers, for example vinyltriethoxysilane, vinyltris(beta-methoxyethoxy)silane, methacryloylpropyltrimethoxysilane, gamma-aminopropyltriethoxysilane, gamma-mercaptopropyltrimethoxysilane, and the like. In a particular embodiment, bis(3-triethoxysilylpropyl)tetrasulfide is used. Metal oxides that can be used include ZnO, CaO, MgO, Al2O3, CrO3, TiO2, FeO, Fe2O3, and NiO. These can be used as oxides or as the corresponding fatty acid compound, preferably as a stearate. Among these, zinc oxide is preferred.Silane coupling agents Typical coupling agents ensure a stable chemical and / or physical interaction between the individual components, for example fillers and rubbers. These are typically sulfur-containing compounds, organosilanes, or polysiloxanes. Coupling agents that carry a polysulfide group and an alkoxysilyl group are preferred; silane polysulfides are particularly preferred, for example bis((C1-C4)alkoxy(C1-C4)alkylsilyl(C1-C4)alkyl)polysulfides (particularly disulfides, trisulfides, or tetrasulfides), such as bis(3-trimethoxysilylpropyl)polysulfide or bis(3-triethoxysilylpropyl)polysulfide. Further examples are bis(3-triethoxysilylpropyl)tetrasulfide (TESPT) of the formula [(C2H5O)3Si(CH2)3S2]2, or bis(triethoxysilylpropyl)disulfide (TESPD) of the formula [(C2H5O)3Si(CH2)3S]2.Other examples are bis(mono(C1-C4)alkoxydi(C1-C4)alkylsilylpropyl)polysulfide, especially disulfides, trisulfides, or tetrasulfides), especially bis(monoethoxydimethylsilylpropyl)tetrasulfide. Composition: For example, in the tread compound of a vehicle tire, the butyl rubber makes up 5 to 40, preferably 5 to 25, phr. "Phr" (parts per hundred rubber) indicates the composition based on 100 parts by mass of the polymer blend. 231396 11 Polybutadienes can make up 30 to 50 phr, styrene-butadiene copolymers 40 to 70 phr, and polyisoprenes 0 to 20 phr, with the proviso that the sum of these polymers is 100 phr. All non-rubber constituents are based on the sum of these polymers. The proportion of fillers, particularly carbon black and silicates, is generally 20 to 200 phr, preferably 30 to 150 phr. The proportion of plasticizers is generally 10 to 30 phr. According to the invention, the reaction products of polyisobutene with elemental sulfur and, optionally, their hydrolysis products are added to these rubbers.Polyisobutene and polyisobutene derivatives are described in more detail below. Suitable isobutene sources for the production of such homopolymers or copolymers containing isobutene in polymerized form include both pure isobutene and isobutene-containing C4 hydrocarbon streams, for example, C4 raffinates, in particular "raffinate 1," C4 cuts from isobutane dehydrogenation, C4 cuts from steam crackers, and from FCC crackers (fluid-catalyzed cracking), provided they are largely freed of the 1,3-butadiene they contain. A C4 hydrocarbon stream from an FCC refinery unit is also known as a "b / b" stream. Other suitable isobutene-containing C4 hydrocarbon streams include, for example, the product stream from a propylene-isobutane co-oxidation or the product stream from a metathesis unit, which are generally used after conventional purification and / or concentration.Suitable C4 hydrocarbon streams generally contain less than 500 ppm, preferably less than 200 ppm, of butadiene. The presence of 1-butene and cis- and trans-2-butene is largely uncritical. Typically, the isobutene concentration in the aforementioned C4 hydrocarbon streams is in the range of 40 to 60 wt. %. Thus, raffinate 1 generally consists essentially of 30 to 50 wt. % isobutene, 10 to 50 wt. % 1-butene, 10 to 40 wt. % cis- and trans-2-butene, and 2 to 35 wt. % butanes; In the polymerization process according to the invention, the unbranched butenes in the raffinate 1 generally behave virtually inertly and only the isobutene is polymerized. In a preferred embodiment, the monomer source used for the polymerization is a technical C4 hydrocarbon stream having an isobutene content of 1 to 100% by weight, in particular 1 to 99% by weight, especially 1 to 90% by weight, particularly preferably 30 to 60% by weight.-%, in particular a raffinate 1 stream, a b / b stream from an FCC refinery unit, a product stream from a propylene-isobutane co-oxidation or a product stream from a metathesis unit. Particularly when using a raffinate 1 stream as the isobutene source, the use of water as the sole or as a further initiator has proven advantageous, especially when polymerizing at temperatures from -20°C to +30°C, in particular from 0°C to +20°C. At temperatures from -20°C to +30°C, in particular from 0°C to 231396 12 +20°C, however, the use of an initiator can also be dispensed with when using a raffinate 1 stream as the isobutene source. The isobutene or the isobutene-containing C4 hydrocarbon stream can originate at least partially, preferably completely, from renewable sources, as described, for example, in WO 2012 / 40859 A1, particularly from page 5, line 9 to page 6, line 24. The proportion of isobutene from renewable sources in the total isobutene used, measured according to ASTM D 6866, as described in WO 2012 / 40859 A1, is advantageously at least 1% by weight, preferably at least 2% by weight, more preferably at least 10% by weight, most preferably at least 25% by weight, and in particular at least 50% by weight. The proportion of isobutene from renewable sources can be up to 100% by weight, preferably up to 95% by weight, particularly preferably up to 90% by weight, very particularly preferably up to 85% by weight and in particular up to 80% by weight.Isobutene obtained from renewable raw materials can be characterized by the fact that. 14 C / 12 C isotope ratio is determined, preferably according to ASTM D 6866 ("Determining the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis"). According to this test method, the 14 C / 12 C isotope ratio of a sample was measured and compared with the 14 C / 12 C isotope ratio in a standardized 100% biobased material. The result is the biobased content in the sample. The application of ASTM-D6866 to derive the "biobased content" is based on the same concepts as radiocarbon dating, but without the use of age equations. The analysis is performed by determining a ratio of the amount of radiocarbon ( 14C) is determined in an unknown sample compared to that of a modern reference standard. This figure is expressed as a percentage with the unit "pMC" (percent modern carbon). If the material being analyzed is a mixture of present-day radiocarbon and fossil carbon (with very low radiocarbon content), the resulting pMC value correlates directly with the amount of biomass material present in the sample. "Bio-based materials" are organic materials made from carbon derived from CO2 recently (on a human timescale) fixed from the atmosphere by solar energy (photosynthesis). On land, this CO2 is absorbed or fixed by plants (e.g., agricultural crops or forest plantations). In the oceans, CO2 is captured or fixed by photosynthesis by and in bacteria or phytoplankton.Thus, a bio-based material has an isotope ratio of. 14 C / 12 C greater than 0. In contrast, a fossil material has a 14 C / 12 C isotope ratio of about 0. A small part of the carbon atoms of carbon dioxide in the atmosphere is the radioactive isotope 14 C, which is formed when atmospheric nitrogen is hit by a neutron produced by cosmic radiation, causing the nitrogen to lose a proton and form carbon of atomic mass 14 ( 14 C), which is then immediately oxidized to carbon dioxide. A small but measurable portion of atmospheric carbon is in the form of 14 CO2. Atmospheric carbon dioxide is assimilated by green plants to produce carbon dioxide during the process known as photosynthesis. known process to produce organic molecules. Virtually all life forms on Earth depend on the production of organic molecules by green plants to generate the chemical energy that enables growth and reproduction. Therefore, the 14 C, which forms in the atmosphere, ultimately part of all life forms and their biological products, which accumulate biomass and organisms that feed on biomass with 14 C. In contrast, carbon from fossil sources, especially oil or coal, does not have the characteristic 14 C: 12 C ratio of renewable organic molecules derived from atmospheric carbon dioxide. In a preferred embodiment of the present invention, the isobutene used in the polyisobutene has a bio-based content, measured as 14 C: 12C ratio ASTM-D6866 of more than 0%, preferably at least 1%, more preferably at least 5%, most preferably at least 10%, in particular at least 20% and especially at least 25%. This bio-based proportion can advantageously be at least 30%, preferably at least 40, more preferably at least 50, most preferably at least 66, in particular at least 75 and especially at least 85%. With a proportion of at least 90%, preferably at least 95%, more preferably at least 98% and even 100%, this can be referred to as predominantly or entirely bio-based isobutene. According to this embodiment, resources are conserved and the product is at least partially produced using renewable raw materials.In another embodiment of the present invention, the isobutene used in the polymerization can be obtained entirely from renewable raw materials or consist of mixtures of isobutene from renewable and fossil sources. This embodiment is particularly preferred where and as long as isobutene from renewable sources is not available in industrially sufficient quantities and economically. The isobutene-containing monomer mixture mentioned may contain small amounts of contaminants such as water, carboxylic acids, or mineral acids without critical losses in yield or selectivity. It is expedient to avoid an accumulation of these contaminants by removing such pollutants from the isobutene-containing monomer mixture, for example by adsorption onto solid adsorbents such as activated carbon, molecular sieves, or ion exchangers. 14 Although less preferred, monomer mixtures of isobutene or of the isobutene-containing hydrocarbon mixture can also be reacted with olefinically unsaturated monomers which are copolymerizable with isobutene. If monomer mixtures of isobutene are to be copolymerized with suitable comonomers, the monomer mixture preferably contains at least 5% by weight, more preferably at least 10% by weight and in particular at least 20% by weight of isobutene, and preferably at most 95% by weight, more preferably at most 90% by weight and in particular at most 80% by weight of comonomers. According to the invention, the reaction products of polyisobutene with elemental sulfur are generally added to the rubber mixture in amounts of 2 to 20, preferably 4 to 14, more preferably 5 to 10 phr.Typically, the reaction products of polyisobutene with elemental sulfur are added to the rubber compound along with the other components and heated in a kneader or extruder to initiate vulcanization. It may also be advantageous to first thoroughly mix the rubber compound and the filler materials with the reaction products of polyisobutene with elemental sulfur and then later add the other components, particularly antioxidants, activators, and / or plasticizers. The processes for vulcanizing and producing rubber compounds are known per se and can be applied to the use of the reaction products of polyisobutene with elemental sulfur.An advantage of the reaction products of polyisobutene with elemental sulfur is that they have a beneficial effect on improving at least one of the following properties: dispersion coefficient, particle size, wet grip, abrasion resistance, and rolling resistance of rubber-containing tires. The reaction products of polyisobutene with elemental sulfur are particularly suitable for improving the dispersion of fillers, especially silica, in rubber compositions. They also exhibit a particular advantage in reducing rolling resistance. Furthermore, the reaction products of polyisobutene with elemental sulfur exhibit an advantage with regard to wet grip at low temperatures (-10°C) and / or rolling resistance and / or abrasion resistance of the tires containing them. The compounds of the invention preferably improve at least two of these three. 231396 15 properties. A particular advantage is that the reaction products of polyisobutene with elemental sulfur simultaneously exhibit advantages in wet grip at low temperatures (-10 °C) and in rolling resistance and abrasion resistance of the tires. By increasing the abrasion resistance of the tires, the release of microplastics from tire wear during motor vehicle operation is reduced. An advantage of the reaction products of polyisobutene with elemental sulfur is that they enhance the effect of vulcanizing agents in rubber compounds and accelerate vulcanization. This was not recognized in WO 2022 / 223345.where these compounds were described as vulcanizing agents. Thus, the use of the reaction products of polyisobutene with elemental sulfur in rubber compositions to shorten the vulcanization time represents a further embodiment of the invention. Accordingly, the present invention further provides a process for accelerating vulcanization in the production of rubber-containing tires, in which - at least one rubber is mixed with - carbon black and / or silicates and - at least one processing aid and / or additive for improving at least one performance property of the tire in a kneader and / or extruder, characterized in that at least one reaction product of polyisobutene with elemental sulfur is added to the rubber composition before and / or during processing. A further subject matter are rubber compositions containing - at least one rubber,selected from the group consisting of isobutene-isoprene rubber, styrene-butadiene rubber and natural rubber, - at least one filler selected from the group consisting of calcium carbonate, clays, mica, silica, silicates, talc, bentonite, titanium dioxide, aluminum oxide, zinc oxide and carbon black, - at least one antioxidant, preferably a p-phenylenediamine, - at least one peroxide and / or polyamine as a hardener and / or crosslinker, - at least one activator for the vulcanization process selected from the group consisting of amines, diamines, guanidines, thioureas, thiatols, thiramen, sulfenamides, sulfenimides, thiocarbamates and xanthates, - at least one silane crosslinker selected from the group consisting of bis((C1-C4)alkoxy(C1-C4)alkylsilyl(C1-C4)alkyl)polysulfides, (especially disulfides, trisulfides or tetrasulfides), bis(3-trimethoxysilylpropyl), bis(3-triethoxysilylpropyl)polysulfide,Bis(3-triethoxysilylpropyl)tetrasulfide (TESPT) of the formula [(C2H5O)3Si(CH2)3S2]2, and, 231396 16Bis(triethoxysilylpropyl) disulfide (TESPD) of the formula [(C2H5O)3Si(CH2)3S]2, and at least one reaction product of polyisobutene with elemental sulfur. Furthermore, the reaction products of polyisobutene with sulfur are suitable for alcohols R released during the production of rubber compounds for tires. 6 OH, especially ethanol, so that lower emissions are released during production. The following products are likely to be formed: R S 231396 17 OR , where R 6 the rest of the released alcohol R 6OH is preferably ethyl. These compounds, in turn, exhibit the same effects as the compounds according to the invention, namely improving the dispersion of fillers, particularly silica, in rubber compositions, reducing rolling resistance, providing an advantage with regard to wet grip at low temperatures (-10 °C), and / or rolling resistance and / or abrasion resistance of the tires containing them. The compounds preferably improve at least two of these three properties. A particular advantage of these compounds is that they simultaneously exhibit an advantage with regard to wet grip at low temperatures (-10 °C), rolling resistance, and abrasion resistance of the tires. Furthermore, by increasing the abrasion resistance of the tires, the release of microplastics from tire wear during motor vehicle operation is reduced, and the effect of vulcanizing agents in rubber compositions is enhanced and vulcanization is accelerated.A further advantage of the present invention is that the reaction products of polyisobutene, preferably highly reactive polyisobutene, with elemental sulfur are capable of reacting with other components of the rubber compositions, for example, with the silane coupling agent. This increases the compatibility of the individual components of the rubber compositions with each other. The following idealized structures are formed: 231396 18 SX where R 1 as defined above, X for –(S)x–R 25 –Si(OR 26 )3, x for 1, 2, 3 or 4 R 25an alkylene radical having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, particularly preferably 2 or 3 carbon atoms and very particularly preferably selected from the group consisting of methylene, 1,2-ethylene, 1,2-propylene, 1,3-propylene, 1,4-butylene, 5-oxa-1,5-pentylene and 1,6-hexylene, in particular 1,3-propylene, and R26 represents C1- to C6-alkyl, preferably C1- to C4-alkyl, particularly preferably methyl, ethyl, n-propyl, isopropyl, n-butyl or tert-butyl, very particularly preferably methyl, ethyl or n-butyl, in particular methyl or ethyl and especially methyl. These compounds also show the same effects as the compounds according to the invention, namely to improve the dispersion of the fillers, especially silica in the Rubber compounds to reduce rolling resistance, advantage in terms of wet grip at low temperatures (-10 °C) and / or 231396 19 rolling resistance and / or abrasion resistance of the tires containing them. The compounds preferably improve at least two of these three properties. A particular advantage of these compounds is that they simultaneously exhibit an advantage with regard to wet grip at low temperatures (-10 °C) and rolling resistance and abrasion resistance of the tires. Furthermore, by increasing the abrasion resistance of the tires, the release of microplastics from tire wear during motor vehicle operation is reduced, and the effect of vulcanizing agents in rubber compositions is enhanced and vulcanization is accelerated. In particular, they improve compatibility with the silicates in the rubber compositions. The present invention is illustrated by the following examples, without being limited thereto.Examples Preparation examples Compound 1 100.00 g polyisobutene (Glissopal® 1000 from BASF SE, Ludwigshafen, number average molecular weight Mn (determined by GPC) approx. 1000 g / mol, polydispersity approx. 1.6, content of alpha double bonds (determined by. 13CNMR) approx. 88%, beta-double bonds 6%, were mixed with 17.10 g (0.53 mol) of sulfur and stirred for one hour at 220 °C. The reaction mixture was then stirred for a further hour at 240 °C. The reaction mixture was cooled to room temperature, mixed with 150 ml of heptane, and filtered. The solvent in the filtrate was removed under vacuum (yield = 101.90 g). Method Description Improvement of the Dispersion Coefficient The macrodispersion (Dispersion Index Analysis System, DIAS) of the undistributed filler agglomerates (particles) is determined by comparing the reflectance of the particle surfaces with the total observation area using a light microscope at 125x magnification of at least 10 images. This results in the degree of dispersion (given in percent), whereby the filler volume content and the empty volume of the fillers are taken into account using correction factors. The aim is to achieve a high dispersion coefficient.Determination of particle size. 231396 20 The mean particle diameter was determined optically along with the dispersion coefficient calculation. A small particle size is advantageous. Wet grip at low temperatures (-10 °C) and rolling resistance. A strip test specimen (40 × 10 × 2 mm) of the produced rubber compound was tested in an ARES test device from Rheometric Scientific. TM subjected to a dynamic mechanical analysis (DMA). Measurement parameters: Temperature range: -60 to 80 °C Frequency: 1 Hz Amplitude: 0.5% The tan(δ) value at -10 °C is considered a measure of traction on wet roads at low temperatures, while the tan(δ) value at +60 °C is considered a measure of rolling resistance. High values ​​for tan(δ) -10°C mean a high wet grip and are advantageous, low values ​​for tan(δ) 60°Cmean low rolling resistance and are desirable. Abrasion resistance The abrasion was measured according to DIN ISO 4649 in a Frank abrasion apparatus at a load of 10 N over a sliding length of 40 m and a rotation of 40 m. -1 determined. The abrasion index is given in percent [%]; higher values ​​are positive. Vulcanization acceleration A silica-containing rubber compound as described below was treated at 160 °C at an amplitude of 0.5% and a frequency of 1.67 Hz in a Monsanto Rheometer MDR 2000E, with the torque being monitored over time. The increase in torque describes the progress of vulcanization. Furthermore, the rubber compound was vulcanized at 160 °C at a load of 280 bar in a Rucks Maschinenbau KV 207.00 apparatus to determine the t90 value. A reduction in the t 90 -Time is advantageous. 231396 21 Application Examples Silica-containing ("reference") rubber compositions were produced as a comparison or with the additives according to the invention with the following composition: Quantity [phr] Function Designation Reference Rubber SBR (high-Tg) NS6161) 100Silica U7000 GR 2) 80Silane Si 693) 8Plasticizer Vivatec 500 37.5Activator ZnO 2.5Activator Stearic Acid 1Antioxidant IPPD 4) 2Accelerator DPG 5) 2Accelerator CBS 6) 1.7Crosslinker Sulfur 1.41) Rubber Nipol NS616 (modified S-SBR, styrene content: 20 wt%, vinyl group content: 67 mol%, SP value: 17.25 (J / cm 3 ) 1 / 2 , Tg: -25°C, Mw: 510,000, non-oil-extended) manufactured by ZEON CORPORATION (SBR1 in EP 3263360 A1, paragraph

[0054] ) 2) Amorphous SiO2, Ultrasil 7000 GR from Evonik 3) Bis(triethoxysilylpropyl)tetrasulfide 4) IPPD: N-isopropyl-N'-phenyl-1,4-phenylenediamine 5) DPG: N,N'-diphenylguanidine 6) CBS: N-cyclohexylbenzothiazole-2-sulfenamide Rubber compositions according to the invention: Silica-containing rubber composition K1 was prepared analogously to the silica-containing reference rubber composition reference by adding the stated amount of the compounds according to the invention. To compensate, the proportion of plasticizer was reduced accordingly. 231396 22 Quantity [phr]Function Designation K1Rubber SBR (high-Tg)100 NS616Silica U7000 GR 80Silane Si 69 8Compound 1 5Plasticizer Vivatec 500 32.5Activator ZnO 2.5Activator stearic acid 1Antioxidant IPPD 2Accelerator DPG 2Accelerator CBS 1.7Crosslinker sulfur 1.4These rubber compositions according to the invention were compared with the silica-containing reference rubber composition in the application examples given.Example 1 (Improvement of the dispersion coefficient) Dispersion coefficient [%] R eferenz 61 K1 71 Example 2 (Reduction of particle size) Particle size R eferenz 180 K1 140 Example 3 (Wet grip at low temperatures (-10 °C))Wet grip (tan(δ)-10°C) R eferenz 0,83 K1 1,00 Example 4 (Rolling resistance) Rolling resistance R eferenz 0,14 K1 0,041 Example 5 (Abrasion resistance) Abrasion resistance R eferenz 129 K1 139 Example 6 (Acceleration of vulcanization) t90 [min] R eferenz 18,60 K3 16,82

Claims

24 patent claims 1. Verwendung von Umsetzungsprodukten von Polyisobuten, bevorzugt hochreaktivem Polyisobuten, mit elemental sulfur and their hydrolysis products to improve at least one of the following properties - Dispersionskoeffizient - Teilchengröße - Nasshaftung - Abriebsfestigkeit - Rollwiderstand of rubber-containing tires or to accelerate vulcanization in rubber compounds.

2. Verwendung gemäß einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß es sich bei dem Kautschuk um einen Isobuten-Isopren-Kautschuk handelt.

3. Verwendung gemäß einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß es sich bei dem Kautschuk um einen Styrol-Butadien-Kautschuk handelt.

4. Verwendung gemäß einem der vorstehenden Ansprüche zur Verbesserung gleichzeitig mindestens zweier, bevorzugt aller drei der folgenden Eigenschaften - Nasshaftung - Abreibsfestigkeit - Rollwiderstand of rubber-containing tires.

5. Verwendung gemäß einem der Ansprüche 1 bis 4 zur Verringerung von Mikroplastik aus Abrieb von Reifen.

6. Verwendung gemäß einem der Ansprüche 1 bis 4 zur Verringerung des Kraftstoffverbrauchs und damit associated emissions by reducing the rolling resistance of rubber-containing tires.

7. Verfahren zur Beschleunigung der Vulkanisierung in der Herstellung von Kautschuke-enthaltenden Reifen, in which one - mindestens einen Kautschuk mit - Ruß und / oder Silikaten und - mindestens einem Prozesshilfsmittel und / oder Additiv zur Verbesserung mindestens einer 231396 25 Performance characteristic of the tire mixed in a kneader and / or extruder, d adurch gekennzeichnet, dass man der Kautschukmasse vor und / oder während der Verarbeitung adding at least one reaction product of polyisobutene with elemental sulfur as described in claim 1.

8. Verwendung und Verfahren gemäß einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß das Reaction product of at least one of the two heterocyclic products and mfasst, worin der Rest R1 das um eine Isobuteneinheit verkürzte Polyisobuten bedeutet, das alsstarting material was used.

9. Verwendung und Verfahren gemäß einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß das Reaction product additionally at least one compound of the following formulas 231396 26 RRRR S, wherein the residue R 1 which means polyisobutene shortened by one isobutene unit, which was used as starting material. 231396 27 10. Verwendung gemäß einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß der Anteil an Monomers from renewable sources in the starting materials for the polyisobutene used, measured according to ASTM D 6866, is at least 1 wt.%, preferably at least 2, particularly preferably at least 10, very particularly preferably at least 25 and in particular at least 50 wt.% and up to 100 wt.%.

11. Kautschukmasse, enthaltend - mindestens einen Kautschuk, ausgewählt aus der Gruppe bestehend aus Isobuten-Isopren-Kautschuk, Styrene-butadiene rubber and natural rubber, - mindestens einen Füllstoff, ausgewählt aus der Gruppe bestehend aus Kalziumcarbonat, Tone, Glimmer, Silica, silicates, talc, bentonite, titanium dioxide, aluminum oxide, zinc oxide and carbon black, - mindestens einem Antioxidans, bevorzugt einem p-Phenylendiamin, - mindestens einem Peroxid und / oder Polyamin als Härter und / oder Vernetzer, - mindestens einem Aktivatoren für den Vulkanisierungsprozeß ausgewählt aus der Gruppe bestehendfrom amines, diamines, guanidines, thioureas, thiatols, thiramen, sulfenamides, sulfenimides, thiocarbamates and xanthates, - mindestens einem Silanvernetzer ausgewählt aus der Gruppe bestehend aus Bis((C1-C4)alkoxy(C1- C 4 )alkylsilyl(C 1 -C 4 )alkyl)polysulfides, (especially disulfides, trisulfides or tetrasulfides), bis(3-trimethoxysilylpropyl), bis(3-triethoxysilylpropyl)polysulfide, bis(3-triethoxysilylpropyl)tetrasulfide (TESPT) of the formula [(C 2 H 5 O) 3 Itself 2 ) 3 S 2 ] 2 , and bis(triethoxysilylpropyl)disulfide (TESPD) of the formula [(C 2 H 5 O) 3 Itself 2 ) 3 S] 2 , and at least one reaction product of polyisobutene, preferably highly reactive polyisobutene, with elemental sulfur.

12. Kautschukmasse gemäß Anspruch 11, dadurch gekennzeichnet, daß der Anteil an Monomeren ausrenewable sources of the starting materials for the synthetic rubbers, measured according to ASTM D 6866, is at least 1% by weight, preferably at least 2% by weight, particularly preferably at least 10% by weight, very particularly preferably at least 25% by weight and in particular at least 50% by weight and up to 100% by weight.

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