Polyisobutene derivatives as an additive in rubbers

Abstract

The present invention relates to the use of various polyisobutene derivatives as additives in rubbers, in particular for the dispersion and compatibilization of additives in rubbers for vehicle tires.

Description

Polyisobutene derivatives as additives in rubbers Description The present invention relates to the use of various polyisobutene derivatives as additives in rubbers, particularly for dispersing and compatibilizing additives in rubbers for vehicle tires. Modern vehicle tires are subject to increased demands on their properties, not least from a sustainability perspective, in particular low rolling resistance in order to reduce fuel consumption and associated emissions, and high abrasion resistance in order to reduce the emission of tire wear particles, for example in the form of microplastics, into the environment and to increase the service life of the tires without simultaneously impairing the grip of the tires on the surface under various conditions (e.g. temperature, weather conditions, road conditions). To improve these properties, vehicle tires can contain various fillers and vulcanization accelerators in their rubber compounds. These fillers 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 effectiveness. There is therefore a need for additives that can be used to better incorporate filler materials such as carbon black, silicates or zinc oxide, as well as the other additives mentioned, into rubbers and to fulfil the functions in the rubbers or during their production, for example as antioxidants, activators or plasticizers. Furthermore, silanes are often used as processing aids in the production of rubber compounds for tires to improve the blending of carbon black or silica. These release alcohols, particularly ethanol, during the process. This represents an emission that must be avoided or reduced for occupational health and safety and environmental reasons. WO 2007 / 70063 discloses the incorporation of polyisobutene succinic anhydride (PIBSA) as a processing aid into brominated butyl rubbers, which improves viscosity and curing time, facilitating processing. The molecular weight of PIBSA is specified to be between 400 and 5000, with an anhydride functionality of 0.5 to 2.0 mol%, and the number-average molecular weight can reach up to 10,000, although no commercially available products are specified. Effects other than as a processing aid are not stated for the polyisobutene succinic anhydride and cannot be derived from the examples. In DE 19941166 A1, derivatives of polyisobutene succinic anhydride are produced which improve the grip and abrasion resistance in a rubber composition. Polyisobutene succinic anhydride serves exclusively as a starting material for the production of the derivatives, but is not itself added to a rubber composition. US 2007 / 0129477 A1 and US 2018 / 0057674 A1 disclose the use of polyisobutene succinic anhydride to improve dispersion. According to US 2007 / 0129477 A1, clay is dispersed in elastomers, including butyl rubber. US 2021 / 0054116 A1 and EP 3971223 A1 describe the use of reaction products of polyisobutene, unsaturated dicarboxylic anhydride, e.g., maleic anhydride, and a silane component in rubber compounds. However, the production of this component is complex and involves several steps, so there is a need for an additive that is easier to obtain. WO 2009 / 158604 describes the use of metal salts of polyisobutenesuccinic acids with a number-average molecular weight of 250 to 100,000 in rubber compounds to improve the properties of the rubber compounds. EP 3943317 A1 describes polybutene derivatives for rubber preparations containing polyisobutene derivatives, unsaturated dicarboxylic anhydride and at least one alkanolamine, amine-based compounds or polyhydric alcohols. The polybutene derivatives are classified according to paragraph

[0010] referred to as "mixtures", however, the synthesis examples show that they are actually reaction products of polyisobutenylsuccinic anhydride with alkanolamines, amine-based compounds or polyhydric alcohols. Polyisobutenylsuccinic anhydride is used as a comparison in Comparative Example 3 and results in poorer values ​​for wet grip and rolling resistance than the polybutene derivatives tested according to EP 3943317 A1. EP 3943317 A1 contains no disclosure regarding polyisobutenylsuccinic acid. The problem was solved by using polyisobutene derivatives selected from the group consisting of polyisobutenyl-substituted succinic anhydrides (A) of the formula and polyisobutene derivatives (B) of formula (B1) containing at least two carboxylic acid groups and / or carboxylic acid ester groups or (B2) wherein R 1 a straight-chain or branched alkenyl radical having 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, R2 and R 3 independently of one another are hydrogen or a straight-chain or branched alkyl or alkenyl radical, preferably alkyl radical having 1 to 10 carbon atoms, for improving at least one of the following properties - Dispersion coefficient - particle size - Wet grip - Abrasion resistance - rolling resistance of rubber-containing tires or to capture alcohols released during tire production. For the remainder R 1 it is a straight-chain or branched, preferably branched alkenyl radical 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. In a preferred embodiment, the radical R 1a residue from the polymerization of isobutene or an isobutene-containing monomer mixture as described below. In a further embodiment, the residue R 1 a residue from the polymerization of 1- and / or 2-butene, especially 1-butene or a butene-containing monomer mixture. In this case, compounds (A) and (B) are not polyisobutene derivatives, but polybutene derivatives. In a further embodiment, the residue R 1 a residue from the polymerization of propene or a propene-containing monomer mixture. In this case, compounds (A) and (B) are not polyisobutene derivatives, but polypropene derivatives. In contrast to EP 3943317 A1, the compounds of the present invention are not reaction products with alkanolamines, amine-based compounds or polyhydric alcohols. The invention is explained in more detail below: rubber In vehicle tire compounds, especially for the treads, blends of butyl rubber with diene elastomers and other components are used. Such mixtures are described, for example, in WO2019 / 199839 A1, paragraph

[0008] until

[0070] , which is incorporated into the present disclosure by reference. 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 usually have a glass transition temperature Tg of -75 to 0 °C Polybutadienes These 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. The elastomer used is preferably polybutadiene with more than 90% cis-1,4 linkages, 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 include, in particular, 1,3-butadiene, isoprene, and 2,3-dimethyl-1,3-butadiene. Aromatic vinyl compounds can also be polymerized; suitable aromatic vinyl compounds include, 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 predominantly being 1,3-butadiene. The content of 1,2-units is generally 4 to 80 mol.%, and that of cis-1,4-units is more than 80 mol.%. Styrene-butadiene-isoprene terpolymers are also conceivable. Polyisoprene These include 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 These are copolymers of 85 to 99.5 mol%, preferably 90 to 99.5, particularly preferably 95 to 99.5 mol% of C4-C14 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 originate at least partially, preferably 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, particularly preferably at least 10% by weight, very particularly 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, particularly preferably up to 90% by weight, very particularly preferably up to 85% by weight, and in particular up to 80% by weight. Plasticizer 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 Cs fractions of naphtha or steamer field 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, methylcyclopentadiene, or cyclohexene. In particular, these are copolymers of cyclopentadiene and / or dicyclopentadiene with vinylaromatics, especially styrene, α-methylstyrene, o-, m-, or p-methylstyrene, or divinylstyrene. These vinylaromatics are components of the Cg fractions of naphtha or steamer field discharges. Preferred resins as plasticizers are cyclopentadiene and / or dicyclopentadiene copolymers, cyclopentadiene and / or dicyclopentadiene-styrene copolymers, polylimonenes, limonene-styrene copolymers, limonene-cyclopentadiene and / or dicyclopentadiene copolymers, Cs fraction-styrene copolymers and Cs fraction-Cg 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 pim. Silicates are understood here as derivatives of silicic acid, including its 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 m2 / 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 2 after thermomechanical mixing with an elastomer. The selected specific silica can be used alone or in the presence of other fillers, such as carbon black or another conventional silica. A particularly suitable silicon dioxide is, for example, the silicon dioxide 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. antioxidant Antioxidants act against oxidative degradation, in particular p-phenylenediamines are to be mentioned, for example N,N'-alkyl- or aryldisubstituted p-phenylenediamines, particularly preferred is N-(1,3-dimethylbutyl)-N'-phenyl I-1,4-phenylenediamine. Hardeners, crosslinkers, activators The rubber compositions are reacted with the aid of at least one curing agent and at least one crosslinking agent, which are known to the person skilled in the art. Examples include organic peroxides and polyamines. In particular, sulfur is used as a vulcanizing agent. 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. Sulphur, metal oxides, fatty acids, especially stearic acid, and in particular organosilane crosslinkers (see below under silane coupling agents) can be used as crosslinkers, for example vinyl triethoxysilane, vinyl tris (beta-methoxyethoxy) silane, methacryloylpropyl trimethoxysilane, gamma-aminopropyl triethoxysilane, gamma-mercaptopropyl trimethoxysilane and the like. In a particular embodiment, bis-(3-triethoxysilylpropyl)tetrasulfide is used. ZnO, CaO, MgO, Al2O3, CrOa, TiO2, FeO, FeOa, and NiO can be used as oxides or as the corresponding fatty acid compound, preferably as stearate. Among these, zinc oxide is preferred. Silane coupling agent Typical coupling agents ensure a stable chemical and / or physical interaction between the individual components, for example fillers and rubbers. Typically these are sulfur-containing compounds, organosilanes or polysiloxanes. Preferred coupling agents are those which carry a polysulfide group and an alkoxysilyl group; particularly preferred are silane polysulfides, for example bis((Ci-C4)alkoxy(Ci-C4)alkylsilyl(Ci-C4)alkyl)polysulfides (especially disulfides, trisulfides, or tetrasulfides), such as, for example, bis(3-trimethoxysilylpropyl)polysulfide or bis(3-triethoxysilylpropyl)polysulfide. Further examples are bis(3-triethoxysilylpropyl)tetrasulfide (TESPT) of the formula [(C2H5O)3Si(OH2)3S2]2, or bis(triethoxysilylpropyl)disulfide (TESPD) of the formula [(C2H5O)3Si(OH2)3S]2. Other examples are bis(mono(Ci-C4)alkoxy di(Ci-C4)alkylsilylpropyl)polysulfide, especially disulfides, trisulfides or tetrasulfides), especially bis(monoethoxydimethylsilylpropyl)tetrasulfide. composition For example, butyl rubber makes up 5 to 40, preferably 5 to 25, phr in the tread compound of a vehicle tire. "Phr" (parts per hundred rubber) indicates the composition based on 100 parts by mass of the polymer blend. Polybutadienes can make up 30 to 50 phr, styrene-butadiene copolymers 40 to 70 phr, and polyisoprenes 0 to 20 phr, provided that the total of these polymers equals 100 phr. All non-rubber components are based on the total of these polymers. The proportion of fillers, especially carbon black and silicates, is usually 20 to 200 phr, preferably 30 to 150 phr. The proportion of plasticizers is usually 10 to 30 phr. According to the invention, polyisobutenylsuccinic anhydride (A) or its acid or ester derivatives (B) are added to these rubbers. The starting material for this polyisobutenylsuccinic anhydride and its derivatives is polyisobutene. Polyisobutene and polyisobutene derivatives are described in more detail below: The polyisobutene underlying the chain is homo- and copolymers containing isobutene in polymerized form and having a number-average molecular weight Mn of 500 to 50,000, preferably 550 to 40,000, particularly preferably 650 to 30,000, very particularly preferably 750 to 20,000 and in particular 900 to 15,000. In a preferred embodiment, the polyisobutene is one with a Mn of 950 to 1050. Among these polyisobutenes, those with a high content of terminally arranged ethylenic double bonds (o-double bonds) are preferred, particularly those with an o-double bond content of at least 50 mol%, preferably at least 60 mol%, more preferably at least 70 mol%, and most preferably at least 80 mol%. These are referred to as highly reactive polyisobutenes. In a further preferred embodiment, the polyisobutene is one having a Mn of 2300 to 10000. For the production of such homo- or copolymers containing isobutene in polymerized form, both pure isobutene and isobutene-containing C4 hydrocarbon streams are suitable as isobutene sources, for example C4 raffinates, in particular "raffinate 1", C4 cuts from isobutane dehydrogenation, C4 cuts from Steamer fields and 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. The isobutene concentration in the aforementioned C4 hydrocarbon streams is typically 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 are generally virtually inert and only the isobutene is polymerized. In a preferred embodiment, the monomer source used for the polymerization is an industrial C4 hydrocarbon stream having an isobutene content of 1 to 100 wt.%, in particular 1 to 99 wt.%, especially 1 to 90 wt.%, particularly preferably 30 to 60 wt.%, 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. The use of water as the sole or additional initiator has proven particularly effective when using a raffinate 1 stream as the isobutene source, especially when polymerizing at temperatures from -20°C to +30°C, especially from 0°C to +20°C. However, at temperatures from -20°C to +30°C, especially from 0°C to +20°C, the use of an initiator can be omitted 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, more preferably up to 90% by weight, most 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 the 14 C / 12C 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 measured and compared with the 14 C / 12 C isotope ratio in a standardized 100% bio-based material. The result is the bio-based 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 parameter is expressed as a percentage using 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 through solar energy (photosynthesis). On land, this CO2 is absorbed or fixed by plants (e.g., agricultural crops or forest plantations). In the oceans, the CO2 is captured or fixed through 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 14C, 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 organic molecules during the process known as photosynthesis. 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 14C. 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: 12 C 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%. Advantageously, this bio-based proportion can be at least 30%, preferably at least 40%, particularly preferably at least 50%, most particularly 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%, particularly preferably at least 98% and even 100%, this can be described as predominantly or completely bio-based isobutene. According to this embodiment, resources are conserved and the product is manufactured at least partially with 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 can 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 above may contain small amounts of contaminants such as water, carboxylic acids, or mineral acids without causing critical yield or selectivity losses. It is advisable to avoid the accumulation of these contaminants by removing such contaminants from the isobutene-containing monomer mixture, for example, by adsorption on solid adsorbents such as activated carbon, molecular sieves, or ion exchange resins. Although less preferred, monomer mixtures of isobutene or the isobutene-containing hydrocarbon mixture can also be reacted with olefinically unsaturated monomers 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 especially at least 20% by weight of isobutene, and preferably at most 95% by weight, more preferably at most 90% by weight, and especially at most 80% by weight of comonomers. Due to its production process, polyisobutene is a mixture of double bond isomers, which determine the properties and especially the chemical reactivity of polyisobutene. The most important are Isomers with alpha double bonds, as well as Isomers with beta-double bonds where the residue PIB stands for the residue of polyisobutene without the substructure shown. Ideally, these implementation products include - monomaleinated (see below) polyisobutene succinic anhydride selected from the following compounds - bismaleinated (see below) polyisobutene succinic anhydride selected from the following compounds and wherein PI B has the meaning given above and the interconnected broken bond systems each represent a double bond at one of the bonds. Furthermore, further isomers are conceivable, as shown, for example, in WO 2023 / 152258, which, however, only play a minor role in the invention. In a preferred embodiment of the invention, the polyisobutene used for the preparation of the polyisobutenyl succinic anhydride (A) or its acid or ester (B) 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 a 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 usually does not exceed 5%. The content of isomers is determined using the1 H-NMR spectroscopy, with the sensitivity being determined by the frequency of the measuring device. 1 H-NMR spectroscopy was performed at 700 MHz at 25 °C. Isomers were particularly preferably identified using the method 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 preferably 13,000 to 75,000, and especially 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 referred to as medium molecular weight polyisobutene. It is conceivable, although less preferred, to use 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 a content of alpha double bonds of not more than 50%, preferably not more than 40% and particularly preferably not more than 30%. The molecular weight is determined by gel permeation chromatography with polystyrene as standard. The polyisobutene derivatives usable according to the invention are or are based on polyisobutenyl-substituted succinic anhydrides (PIBSA), which are obtainable by ene reaction of highly reactive polyisobutenes with maleic anhydride and serve as starting compounds for the acids or esters. Preferred polyisobutene derivatives are the above-mentioned polyisobutenyl-substituted succinic anhydrides (PIBSA). In a preferred embodiment, highly reactive low molecular weight polyisobutene as defined above is used for these polyisobutenyl-substituted succinic anhydrides. In a further preferred embodiment, a medium molecular weight polyisobutene having a number average molecular weight M n from 10,000 to 100,000 can be used to prepare the polyisobutenyl-substituted succinic anhydrides as described in WO 2017 / 216022. In a preferred embodiment, the polyisobutenyl-substituted succinic anhydrides (PIBSA) to be used also have more than singly substituted products. The ratio of the higher to the monomaleated components can be expressed as the "bismaleation degree" (BMG). The BMG is known per se (see also US 5,883,196) and can be determined using the following formula: BMG = 100% x [(wt-%(BM PIBSA) / (wt-%(BM PIBSA)+wt-%(PIBSA))] where wt-%(X) stands for the respective weight fraction of component X (X = PIBSA (mono-maleated polyisobutene) or BM PIBSA (more than mono-maleated polyisobutene)) in the reaction product of polyisobutene with maleic anhydride. The degree of bismaleation is preferably calculated from the saponification number of the sample according to DIN 53401: 1988-06. If necessary, the sample must be solubilized with a suitable solvent, preferably a 2:1 mixture of toluene and ethanol. It should be noted that only the ratio of the more highly maleated components to the singly maleated components is taken into account, whereas unreacted polyisobutene present in the reaction mixture, for example, that which contains no reactive double bonds, is not included in the determination of the degree of bismaleation. Therefore, the reaction mixture may also still contain unreacted polyisobutene, which usually corresponds to the proportion of the polyisobutene used that contains no reactive double bonds, whereas the proportion of the polyisobutene containing reactive double bonds preferentially reacts completely or almost completely. In a preferred embodiment, the PIBSA have a degree of bismaleation of at least 5%, preferably at least 8%, particularly preferably at least 10%. With further advantage, such reaction products of polyisobutene with a degree of bismaleation of at least 12%, preferably at least 15%, particularly preferably at least 20% can be used. The degree of bismaleation can be up to 60%, preferably up to 55%, particularly preferably up to 50%, especially up to 45%, and especially up to 40%. By choosing suitable reaction conditions, especially a high excess of maleic anhydride, the degree of bismaleation can be increased to up to 80% and even up to 100%. The best results are achieved with a degree of bismaleation of 10 to 50%, preferably 12 to 45% and particularly preferably 15 to 40%. From these polyisobutenyl-substituted succinic anhydrides (PIBSA), the free acids of formula (B1) can be obtained by hydrolysis of the anhydride groups. be manufactured. For hydrolysis, the amount of water corresponding to the desired degree of hydrolysis, based on the anhydride functionalities present, is added, and the PIBSA is heated in the presence of the added water. A temperature of preferably 20 to 150°C is generally sufficient, more preferably 60 to 100°C. If necessary, the reaction can be carried out under pressure to prevent the escape of water. Under these reaction conditions, the anhydride functionalities in the reaction product are generally selectively converted, whereas any carboxylic acid ester functionalities present in the reaction product do not react or at least react only to a minor extent. In the same way, the polyisobutenyl-substituted succinic anhydrides can be reacted with at least one alcohol R 2 OH or R 3 OH in an amount corresponding to the desired degree of conversion, so that mono- or diesters of the formula (B2) arise. The reaction conditions are generally similar to those for hydrolysis. Under mild reaction conditions, only one of the two carboxyl groups of the anhydride structure reacts with the alcohol, forming monoesters. Higher temperatures or longer reaction times are usually required to form diesters. In the alcohol R 2 OH or R 3 OH are R 2 and R 3 independently of one another hydrogen or a straight-chain or branched alkyl or alkenyl radical having 1 to 10 carbon atoms, particularly preferably 1 to 4 carbon atoms, preferably alkyl radical having 1 to 10 carbon atoms, particularly preferably 1 to 4 carbon atoms. Examples of preferred saturated alcohols are methanol, ethanol, iso-propanol, n-propanol, n-butanol, iso-butanol, se-butanol, tert-butanol, n-hexanol, n-heptanol, n-octanol, 2-ethylhexanol, iso-nonanol, n-decanol or 2-propylheptanol. Examples of unsaturated alcohols are allyl alcohol, methallyl alcohol, but-2-en-1-ol, but-3-en-1-ol, 3-methylbut-2-en-1-ol, 3-methylbut-3-en-1-ol, geraniol, farnesol and linalool. Saturated alcohols are preferred over unsaturated ones. For the alcohols R 2 OH and R 3 OH are monoalkyl groups that do not contain any other functionalities, in particular no hydroxy or amino groups. The fact that the residues R 2 and R 3 The advantage of using hydrophobic alkyl or alkenyl residues is that these hydrophobic residues exhibit greater compatibility with the rubber matrix than more hydrophilic residues. This improves the miscibility of the compounds (B2) with the rubber. As a rule, one of the residues R 2 and R 3 hydrogen and the other is a straight-chain or branched alkyl or alkenyl radical having 1 to 10 carbon atoms In a preferred embodiment, the compounds which can be used according to the invention are polyisobutenyl-substituted succinic anhydrides (A), particularly preferably those which have a degree of bismaleation of at least 10% up to 50%, very particularly preferably 12 to 45% and in particular 15 to 40%. In a further preferred embodiment, the compounds which can be used according to the invention are polyisobutene derivatives (B) containing at least one carboxylic acid group, selected from the group consisting of polyisobutenyl-substituted succinic acids (B1) or polyisobutenyl-substituted succinic acid esters (B2), particularly preferably those which have a degree of bismaleation of at least 10% up to 50%, very particularly preferably 12 to 45% and in particular 15 to 40%. These acid group-containing polyisobutene derivatives (B) carry at least two carboxy groups in the form of carboxyl, carboxylate or carboxylic acid ester groups, for example 2 to 4 carboxy groups. The polyisobutenylsuccinic anhydrides (A) or acid group-containing polyisobutene derivatives (B) according to the invention are generally added to the rubber mixture in amounts of 2 to 20, preferably 4 to 14, particularly preferably 5 to 10 phr. Typically, compounds (A) and (B) are added to the rubber compound along with the other ingredients and heated in a kneader or extruder to initiate vulcanization. It may also be advantageous to first thoroughly mix the rubber compound and the fillers together with compounds (A) and (B) and then later add the other ingredients, especially antioxidants, activators, and / or plasticizers. Accordingly, a further embodiment of the present invention is a process for reducing the viscosity of rubber compositions in the manufacture of rubber-containing tires, in which - at least one rubber with - soot 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, wherein at least one polyisobutenylsuccinic anhydride (A) and / or acid group-containing polyisobutene derivative (B) as described above is added to the rubber masses before and / or during processing. The processes for vulcanization and production of rubber compositions are known per se and can be transferred to the use of compounds (A) and (B). It is an advantage of compounds (A) and (B) that they have a beneficial effect on improving at least one of the following properties - Dispersion coefficient - particle size - Wet grip - Abrasion resistance - rolling resistance of rubber-containing tires. The compounds (A) and (B) are particularly suitable for improving the dispersion of fillers, especially silica, in rubber compositions. Furthermore, they show a particular advantage in reducing rolling resistance. During the production of the rubber masses, compounds (A) and (B) further exhibit the advantage of significantly reducing the viscosity of the masses during processing. Furthermore, compounds (A) and (B) exhibit an advantage with respect to wet grip at low temperatures (-10 °C) and / or rolling resistance and / or abrasion resistance of the tires containing them. Compounds (A) and (B) preferably improve at least two of these three properties. It is a particular advantage that compounds (A) and (B) simultaneously exhibit an advantage with respect to wet grip at low temperatures (-10 °C) and rolling resistance and abrasion resistance of the tires. By increasing the abrasion resistance of tires, the release of microplastics from tire wear during motor vehicle operation is reduced. Furthermore, the compounds (A) are suitable for converting alcohols R released during the production of rubber compounds for tires 6OH, especially ethanol, so that fewer emissions are released during production. The mono- or doubly esterified products can be formed from compounds (B1) by esterification, and from compounds (B2) by transesterification. The products formed correspond to the above-mentioned compounds of formula (B2), in which at least one of the radicals R 2 and R 3 a remainder R 6 , preferably ethyl. Conceivably, both radicals R 2 and R 3 a remainder R 6 , preferably ethyl. Analogous products are formed from bismaleic polyisobutene succinic anhydride. Another subject matter is rubber compositions containing - at least one rubber selected from the group consisting of isobutene-isoprene rubber, 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 of natural rubber and polyisoprenes, - 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 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((Ci-C4)alkoxy(Ci-C4)alkylsilyl(Ci-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 bis(triethoxysilylpropyl)disulfide (TESPD) of the formula [(C2H5O)3Si(CH2)3S]2, and at least one compound selected from the group consisting of polyisobutenyl-substituted succinic anhydrides (A) of the formula and polyisobutene derivatives (B) of formula (B1) containing at least one carboxylic acid group or (B2) wherein R 1 a straight-chain or branched alkenyl radical with 9 to 200 carbon atoms R 2 and R 3independently of one another hydrogen or a straight-chain or branched alkyl or alkenyl radical, preferably alkyl radical having 1 to 10 carbon atoms. The compounds (B) are preferred over the compounds (A). A further advantage of the present invention is that compounds (A) and (B) are capable of reacting with other components of the rubber compositions, for example, with the silane coupling agent or silicates. This increases the compatibility of the individual components of the rubber compositions with each other. The reaction product of mono- or bismaleinated compounds with the silane coupling agent is particularly advantageous. The following idealized structures are formed from the monomaleinated polyisobutene succinic anhydride (A): where the residue PI B represents the residue of the polyisobutene without the substructure shown, X for -(S)xR 25 -Si(OR 26)3, x for 1 , 2, 3 or 4 R 25 an 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 R 26 represent Ci- to Ce-alkyl, preferably Ci- to C-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. The analogous structures are formed from the polyisobutenesuccinic acid (B1) and the polyisobutenesuccinic acid ester (B2). These compounds, as well as rubber compositions containing at least one of these compounds, their use in rubber-containing tires, particularly for improving the compatibility of silicates or as coupling agents in rubber-containing tires and their use for improving at least one of the following properties - Dispersion coefficient - particle size - Wet grip - Abrasion resistance - Rolling resistance -Vulcanization speed of rubber-containing tires are also the subject of the present invention. From the reaction with free hydroxy groups of the silicates, polyisobutenyl-substituted succinic anhydrides can be bound to their surface and thus contribute to the compatibilization of the silicates. The reaction products can, for example, have the following structure: as well as the regioisomer in which the bonding to the silicates occurs via the other carboxyl group, whereby the silicon centers shown are exemplary for the silicate, especially for the silicate surface. These compounds, as well as rubber compositions containing at least one of these compounds, their use in rubber-containing tires, particularly for improving the compatibility of silicates, are also the subject of the present invention. The present invention is illustrated by the following examples, but is not limited thereto. Examples Manufacturing examples Connection 1 97.76 g polyisobutene (number average molecular weight Mn (determined by GPC) approx. 550 g / mol, content of alpha double bonds (determined by 13C NMR) approx. 89.0%, beta-double bonds 9.8%) was heated with 19.25 g (1.1 eq.) of maleic anhydride in an autoclave at 215 °C and stirred for 5 h. The reaction mixture was then cooled to 80 °C and treated with 150 ml of heptane. The solution was stirred at 100 °C for 1 h and then filtered. The solvent was removed under vacuum. (Saponification number SV: 138 mg KOH / g) Connection 2 Commercially available, polyisobutenyl-substituted succinic anhydride based on a highly reactive polyisobutene with a number-average molecular weight of approximately 1000 g / mol, available as Glissopal® SA F from BASF SE, Ludwigshafen, saponification number 87 mg KOH / g. Connection 3 104.4 g polyisobutene (number average molecular weight Mn (determined by GPC) approx. 2300 g / mol, content of alpha double bonds (determined by 13C NMR) approx. 84.6%, beta-double bonds 13.6%) was heated with 5.78 g (1.3 eq.) of maleic anhydride in an autoclave at 225 °C and stirred for 5 h. The reaction mixture was then cooled to 80 °C and treated with 150 ml of heptane. The solution was stirred at 100 °C for 1 h and then filtered. The solvent was removed under vacuum. (Saponification number SV: 46 mg KOH / g) Connection 4 150.20 g 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 13C NMR) approx. 88%, beta-double bonds 6%, were heated with 29.4 g (0.30 mol, 2 eq.) of maleic anhydride in an autoclave at 225 °C and stirred for 7 h. The reaction mixture was then cooled to 80 °C and treated with 150 ml of heptane. The solution was stirred at 100 °C for 1 h and then filtered. The solvent, along with unreacted maleic anhydride, was removed in vacuo (yield = 164.00 g). (Saponification number SV: 175 mg KOH / g). A polyisobutenylsuccinic anhydride (PIBSA) with a bismaleation degree of approximately 100% was obtained. Connection 5 122.48 g of a polyisobutenylsuccinic anhydride obtained analogously to compound 2 with a SV of 138 mg KOH / g was dissolved in 100.00 g of toluene. 14.24 g (0.16 mol) of isoprenol was added to the reaction mixture and stirred for 2 h at 120 °C. The reaction mixture was then cooled to room temperature, and the solvent was removed under vacuum (yield = 132.00 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 yields the degree of dispersion (expressed as a percentage), taking correction factors to account for the filler volume content and the void volume of the fillers. The aim is to achieve a high dispersion coefficient. Determination of particle size The mean particle diameter was determined optically together with the calculation of the dispersion coefficient. A small particle size is advantageous. Wet grip at low temperatures (-10 °C) and rolling resistance A strip test specimen (40 x 10 x 2 mm) of the produced rubber compound is subjected to dynamic mechanical analysis (DMA) in an ARES test device from Rheometric Scientific™. Measurement parameters: Temperature range -60 to 80 °C Frequency 1 Hz Amplitude 0.5% The tan(ö) value at -10 °C is considered a measure of traction on wet roads at low temperatures, the tan(ö) value at +60 °C as a measure of rolling resistance. High values ​​for tan(ö).io»c mean high wet grip and are advantageous, low values ​​for tan(ö)eo°c mean low rolling resistance and are desirable. Abrasion resistance The abrasion was measured according to DIN ISO 4649 in an abrasion apparatus from Frank at a load of 10 N over a sliding length of 40 m and a rotation of 40 rrn 1 certainly. The abrasion index is given in percent [%], higher values ​​are positive. Reduction of viscosity during processing The components of the rubber masses were mixed together in the specified proportions and the Mooney viscosity of the mass was determined at a temperature of 100 °C at 2 revolutions / min in a Mooney meter Alpha Technologies MV 2000 E (Mooney ML (1+4) 100 °C). Viscosity is measured in Mooney units (MU). Capture of ethanol released during processing The samples to be analyzed were sealed in a 2 g headspace bottle with a septum. The mixtures were heated to 140 °C for 30 minutes, and the gas phase was analyzed by gas chromatography (Agilent 6890N): Injector temperature: 140 °C, column: 60 m capillary column VF-5 ms, column temperature: 40 °C 4 min isothermal, then with a heating rate of 10 °C / min up to 280 °C isothermal, detector: Agilent mass selective detector 5975C, carrier gas: helium. For occupational health and safety reasons, low values ​​are advantageous. Application examples Silica-containing ("reference") rubber masses were used as a comparison or with the additives according to the invention in an internal mixer Rheomix 3000E (initial temperature 70 °C, speed first stage 60 min 1 , second stage 40 mim 1 ) manufactured with the following composition: 1) 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 By adding the specified amount of the compounds according to the invention, silica-containing Rubber compounds K1 to K5 were manufactured analogously to the silica-containing reference rubber compound "Reference." To compensate, the plasticizer content was partially reduced accordingly. These rubber compositions according to the invention were compared with the silica-containing reference rubber composition "Reference" in the application examples given. Example 1 (Improvement of the Dispersion Coefficient) Example 2 (reduction of particle size) Example 3 (wet grip at low temperatures (-10 °C)) Example 4 (rolling resistance) As a further comparative example, a mixture analogous to rubber compound K2 was presented, in which compound 2 was substituted by the same mass of the simple reaction product of polyisobutene succinic anhydride (based on a polyisobutene with a Mn of approximately 1000 g / mol) with 3-aminopropyl triethoxy silane according to DE 19941166 A1. It can be seen that the compounds 2 and 4, which have the same molecular weight, result in comparable, and somewhat better, rolling resistances in the rubber compounds 2 and 4. Example 5 (Abrasion resistance) Furthermore, the abrasion was determined for a series of rubber compounds which were mixed on a different mixer (Werner & Pfleiderer GK 1.5 E, initial temperature 80°C, speed 60 min 1 , after 6 min 50 - 55 mim 1 , expectoration after 12 - 13 min) were produced: Comparative example as described in Example 4. It can be seen that compounds 2 and 3 in rubber compounds 2 and 3 provide significantly better abrasion resistance than the reaction product according to DE 19941166 A1. Example 6 (Reduction in viscosity during processing) Example 7 (Capturing alcohol released during processing) The components according to the following table were mixed together and heated at 160 °C for 1.5 hours. The gas phase was then analyzed for its ethanol concentration by headspace GC. It can be seen that simply mixing silica with the silane agent SI69 (bis(triethoxysilylpropyl)tetrasulfide) leads to the release of ethanol. This can be drastically reduced by the presence of compound 2 according to the invention.

Claims

Patent claims 1 . Use of polyisobutene derivatives selected from the group consisting of polyisobutene I-substituted succinic anhydrides (A) of the formula and at least two carboxylic acid groups and / or carboxylic acid ester groups containing Polyisobutene derivatives (B) of formula (B1) or (B2) wherein R 1 a straight-chain or branched alkenyl radical having 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, R 2 and R 3 independently of one another are hydrogen or a straight-chain or branched alkyl or alkenyl radical, preferably alkyl radical having 1 to 10 carbon atoms, for improving at least one of the following properties - Dispersion coefficient - particle size - Wet grip - Abrasion resistance - Rolling resistance of rubber-containing tires or to capture alcohols released during tire production.

2. Use according to one of the preceding claims, characterized in that the The rubber is an isobutene-isoprene rubber.

3. Use according to one of the preceding claims, characterized in that the Rubber is a styrene-butadiene rubber.

4. Use according to one of the preceding claims, characterized in that the proportion of Monomers from renewable sources in the starting materials for the synthetic rubbers, measured according to ASTM D 6866, is advantageously 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.

5. Use according to one of the preceding claims for simultaneously improving at least two, preferably all three of the following properties - Wet grip - Abrasion resistance - Rolling resistance of rubber-containing tires.

6. Use according to any one of claims 1 to 5 for reducing microplastics from tire abrasion.

7. Use according to any one of claims 1 to 5 for reducing fuel consumption and associated emissions by reducing the rolling resistance of rubber-containing tires.

8. A process for reducing the viscosity of rubber masses in the manufacture of rubber-containing tires, in which - at least one rubber with - soot 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 the rubber mass is added before and / or during processing adding at least one polyisobutene derivative (A) and / or (B) as described in claim 1.

9. Use of polyisobutene derivatives (A) and / or (B) as described in claim 1 for lowering the Viscosity of rubber compounds in the production of rubber-containing tires.

10. Use and method according to one of the preceding claims, characterized in that the Rest R 1is obtainable by polymerization of isobutene or an isobutene-containing monomer mixture. 11 . Use and method according to one of claims 1 to 10, characterized in that the Polyisobutene derivatives (A) and / or (B) have a degree of bismaleation of at least 5% up to 100%, preferably 10 to 50%.

12. Use and process according to one of claims 1 to 10, characterized in that the polyisobutene derivatives are compounds (B1) and / or (B2), preferably compounds (B2).

13. Rubber composition containing - at least one rubber selected from the group consisting of isobutene-isoprene rubber, 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 of natural rubber and polyisoprenes, - 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 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((Ci-C4)alkoxy(Ci-C4)alkylsilyl(Ci-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 bis(triethoxysilylpropyl)disulfide (TESPD) of the formula [(C2H5O)3Si(CH2)3S]2, and at least one polyisobutene derivative selected from the group consisting of polyisobutene derivatives (B) of the formula (B1) containing at least two carboxylic acid groups and / or carboxylic acid ester groups or (B2) wherein R 1 a straight-chain or branched AI keny Irest with 9 to 200 carbon atoms, R 2 and R 3 are independently hydrogen or a straight-chain or branched alkyl or alkenyl radical, preferably an alkyl radical having 1 to 10 carbon atoms.

Images