SELF-SEALING TIRE SEALANT AND PNEUMATIC VEHICLE TIRE CONTAINING THE TIRE SEALANT

Description

[0001] The invention relates to a self-sealing tire sealant and a pneumatic vehicle tire containing the tire sealant.

[0002] Self-sealing pneumatic vehicle tires are known, for example, from DE 10 2006 059 286 A1 by the applicant. Here, standard tire designs are subsequently provided with a layer of sealant. The self-sealing sealant is a self-adhesive, viscous sealing compound that is applied as a layer from the radially innermost tire layer, in the projection area of ​​the belt package, to the radially innermost tire layer, the largely airtight inner layer. The sealant layer is capable of independently sealing punctures up to five millimeters in diameter. After a puncture has penetrated the tread and through the inner layer, the sealant completely encloses the penetrated foreign body, sealing the interior from the environment and thus preventing a loss of air pressure in the tire. The driver of the vehicle is not forced to immediately replace the defective tire with a full-size spare tire or a temporary spare tire.

[0003] The sealant is characterized by airtightness, strong adhesiveness and balanced flow behavior.

[0004] Document US 5 856 376 A discloses a self-sealing tire sealant according to the preamble of claim 1.

[0005] The object of the present invention is to provide, based on the prior art, a self-sealing tire sealant which is more environmentally friendly and at the same time has the same or even improved sealing effect.

[0006] This object is achieved by the self-sealing tire sealant according to claim 1.

[0007] The use of recycled material makes the sealant more environmentally friendly. At the same time, it continues to exhibit good flowability, good tackiness, and good local stability. The sealing effect of the sealant according to the invention is thus at least at a comparable level, particularly even after the (accidental) removal of the puncture object. It is particularly advantageous if the recycled material is contained in the form of particles, particularly as an inactive or essentially inactive filler. This increases the volume of the sealant and generates increased pressure locally at and in the puncture site, sealing the puncture site better, particularly even after the (accidental) removal of the puncture object. Thus, in this embodiment, the sealant according to the invention even exhibits an improved sealing effect.

[0008] According to advantageous embodiments, the sealant contains 0.2 to 25 wt.% of at least one recycled material. A mixture of various recycled materials is also conceivable, with the total amount preferably being 0.2 to 25 wt.%. This achieves an optimal balance of flow behavior, tackiness, stability, and environmental friendliness of the sealant.

[0009] The data in wt.% refers to the entire sealant including all components, unless otherwise stated.

[0010] According to the invention, the recycled material comprises at least one pyrolysis soot.

[0011] According to advantageous embodiments of the invention, the recycled material comprises at least one regenerated rubber and / or recycled residues of noise absorbers.

[0012] These materials are particularly well-suited because their source materials are used in vehicle tires and are therefore compatible with them. At the same time, they offer economic advantages.

[0013] The materials mentioned can also be used in mixtures.

[0014] Pyrolysis soot is known to those skilled in the art. It is obtained, as described, for example, in "Rubber Chemistry and Technology," Vol. 85, No. 3, pages 408 to 449 (2012), particularly on pages 438, 440, and 442, by thermal decomposition of organic materials at 550 to 800 °C in the absence of oxygen, or by vacuum pyrolysis at comparatively low temperatures in the range of 500 °C.

[0015] In the context of the present invention, the organic materials are preferably used tires and / or vulcanized production waste from tire manufacturing and / or vulcanized tubes, i.e., waste products that must be disposed of. The pyrolysis and recovery of pyrolysis soot therefrom, which is added back to tire compounds according to the invention, thus represents a recycling process.

[0016] The pyrolysis soot is therefore preferably produced by pyrolysis from used tires and / or vulcanized production waste from tire production and / or vulcanized tubes.

[0017] The pyrolysis soot was particularly preferably produced from old tires and / or hoses, most preferably from old tires.

[0018] Vulcanized production waste from tire manufacturing can include all conceivable vulcanized rubber compounds for vehicle tires, including rubber compounds combined with reinforcements.

[0019] This type of pyrolysis carbon black differs from conventional carbon blacks, such as industrial carbon blacks, especially ASTM carbon blacks such as N660, in that it has a higher ash content and a lower polycyclic aromatic hydrocarbon (PAH) content, as can be seen, for example, on the website of BlackBear Carbon BV, http: / / www.blackbearcarbon.com / rfp-international / . Industrial carbon blacks have a high proportion of polycyclic aromatic hydrocarbons (PAH). Industrial carbon blacks have a PAH content of greater than 200 mg / kg.

[0020] Polycyclic aromatic hydrocarbons are harmful to health. The GS specification – a specification pursuant to Section 21, Paragraph 1, No. 3 of the German Product Safety Act (ProdSG) – categorizes, for example, the maximum PAH levels to be observed for materials used in relevant contact / grip and actuation surfaces.

[0021] The PAH content of the pyrolysis carbon black used is less than 50 ppm (mg / kg), particularly preferably less than 40 ppm, most preferably less than 30 ppm, and again preferably less than 10 ppm. The lower limit is in the range of 0.1 mg / kg, which represents the detection limit for PAHs. In principle, the PAH content should be as low as possible.

[0022] The PAH content is determined according to ASTM D-5186.

[0023] In the context of the present invention, the term "pyrolysis carbon black produced by pyrolysis from old tires and / or vulcanized production waste from tire manufacture and / or vulcanized hoses" is understood to mean all pyrolysis carbon blacks from old tires and / or vulcanized production waste from tire manufacture and / or vulcanized hoses known to the person skilled in the art, the listed embodiments being preferred.

[0024] In the context of the present invention, the term "industrial carbon black" refers to the carbon blacks known for tire compounds which are not pyrolysis carbon blacks and which, according to Römpp-Online-Lexikon ©< 2016 Georg Thieme Verlag KG (as of January 8, 2016), usually have an ash content of less than 1 wt.% and are in particular so-called furnace blacks, gas blacks or flame blacks.

[0025] A suitable pyrolysis soot can be obtained, for example, from BBC under the trade name BBC500 or from Pyrolyx AG under the trade name CB e 603.

[0026] The pyrolysis soot preferably has an ash content of 5 to 30 wt.%, particularly preferably 10 to 30 wt.%, and most preferably 10 to 20 wt.%. According to a preferred embodiment of the invention, the ash content is 15 to 20 wt.%.

[0027] The ash content refers only to the pyrolysis soot and is determined by thermogravimetric analysis (TGA) of the pyrolysis soot according to ASTM D1506.

[0028] With such an ash content, particularly good physical properties and also particularly good airtightness of the sealant are achieved.

[0029] The pyrolysis soot further preferably has a sulfur content of greater than 1 wt.%, particularly preferably greater than 2 wt.%, very particularly preferably 2 to 6 wt.%, again very particularly preferably 2 to 4 wt.%, and again very particularly preferably 2.2 to 4 wt.%.

[0030] With such a sulfur content, particularly good physical properties of the sealant are achieved.

[0031] The sulfur content refers only to the pyrolysis soot and is determined using ASTM D4239 of the pyrolysis soot.

[0032] The pyrolysis soot further preferably has a carbon content of 64 to 87 wt.%, particularly preferably 74 to 87 wt.%, most preferably 78 to 87 wt.%.

[0033] It is known to the person skilled in the art that the weight fractions of pyrolysis soot consist of ash, sulfur and predominantly (> 50 wt%) carbon.

[0034] According to advantageous embodiments, the pyrolysis soot has a nitrogen surface area (BET surface area, iodine adsorption number according to ASTM D 1510) of 5 to 100 g / kg and a DBP number according to ASTM D 2414 of 30 to 130 ml / 100g.

[0035] According to the invention, the amount of pyrolysis soot contained is 2 to 10 wt.%, although a mixture of different pyrolysis soots is also conceivable, the stated amount then representing the total amount of pyrolysis soot.

[0036] According to an advantageous embodiment of the invention, the recycled material is at least one regenerated rubber.

[0037] "Reclaimed rubber" (regenerated or engl. Reclaim) is obtained from sulfur-crosslinked rubber vulcanizates by splitting the sulfur bridges, whereby the rubber compounds are converted from the elastic to the plastic state by the devulcanization process (devulcanized rubber compounds).

[0038] Processes for the regeneration of sulfur-cured rubber vulcanizates using various substances and in different apparatuses are known in the art, including steam regeneration, mechanical regeneration, thermal regeneration, regeneration by sound waves, regeneration by radiation and chemical regeneration.

[0039] The term "regenerated rubber" in principle also includes the use of various regenerated rubbers, unless otherwise stated or otherwise evident.

[0040] The starting materials for reclaimed rubber include all vulcanized rubber articles, such as, for example and preferably, sulfur-cured rubber vulcanizates derived from scrap tires or conveyor belts, or from vulcanized waste generated during the production of technical rubber articles or pneumatic vehicle tires. In this case, one or more comminution steps often take place before the actual reclaiming process, resulting in vulcanized rubber granules or vulcanized rubber powder or flour.

[0041] Rubbers that are not yet vulcanized are also referred to as raw rubbers in the context of the present invention. This includes all forms of raw rubber known to those skilled in the art, such as, in particular, raw rubber bales or sheets.

[0042] The rubber underlying the regenerated rubber is preferably selected from the group consisting of natural rubber (NR), synthetic polyisoprene (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), butyl rubber (IIR), and halobutyl rubber. Such rubbers are used particularly in vehicle tires and are compatible with the components of the pneumatic vehicle tire as well as the other components preferably contained in the sealant. Thus, old tires, in particular, can be reused according to the invention through a recycling process.

[0043] According to a particularly advantageous embodiment of the invention, the regenerated rubber comprises regenerated butyl rubber (IIR), although other regenerated rubbers may also be included.

[0044] According to a particularly advantageous embodiment of the invention, the regenerated rubber is regenerated butyl rubber (IIR).

[0045] According to an advantageous embodiment of the invention, the amount of regenerated rubber contained is 10 to 25 wt.%.

[0046] This ensures that the puncture site is closed particularly effectively, especially after the (accidental) removal of the puncture object.

[0047] According to advantageous embodiments, the regenerated rubber has a Mooney viscosity - according to ASTM D1646 - ML 1+4 at 100 °C of 30 to 60 Mooney units, particularly preferably 35 to 55, most preferably 35 to 45 Mooney units.

[0048] With such a viscosity, particularly good miscibility and processability is achieved.

[0049] According to an advantageous embodiment of the invention, the recycled material is reprocessed residues of noise absorbers.

[0050] "Recycled residues" are understood to mean, in particular, those residues of noise absorbers that arise during the production of articles containing one or more noise absorbers (such as noise-optimized vehicle tires), particularly as waste that cannot be used for the respective article. Reprocessing can include shredding, cleaning, and drying steps.

[0051] In principle, the noise absorber can be any material that is specifically used as a noise absorber or is suitable for this purpose. In particular, this applies to noise absorbers such as those used in noise-optimized vehicle tires.

[0052] Preferably, this is at least one porous material. Porous materials have the particular advantage that, in addition to absorbing noise, they also contribute a moderate weight, so that, for example, the rolling resistance properties of a tire are not unnecessarily impaired by the sealant.

[0053] The porous material from which the noise absorber is formed is, for example, selected from the group containing polyurethane, in particular polyurethane foams on a polyether basis and / or polyurethane foams on a polyester basis with a density of 18 to 300 kg / m 3< , preferably 30 to 35 kg / m 3< , and a hardness of 6.5 kilo-pascals, polyester with a density of 18 to 300 kg / m 3< preferably 30 to 35 kg / m 3< , and a hardness of 6.5 kilo-pascals, polyether, as well as any porous, sound-absorbing material mixtures, such as glass or rock wool, textile looped fabric, textile deep-pile fabric, textile fabric, nonwoven materials or cork

[0054] According to preferred embodiments of the invention, the noise absorber comprises at least one material selected from the group consisting of polyurethane foams, glass wool, rock wool, textile looped fabrics, textile deep pile fabrics, textile fabrics, nonwoven materials and cork.

[0055] According to preferred embodiments of the invention, the noise absorber comprises a porous foam that is solid at room temperature.

[0056] The recycled residues therefore represent, for example, shredded and possibly cleaned residues of foam waste.

[0057] According to an advantageous embodiment of the invention, the material of the noise absorber is at least one polyurethane, preferably in the form of a porous foam. Polyurethane is particularly suitable due to its specific density and other material properties, as well as its availability.

[0058] According to an advantageous embodiment of the invention, the amount of recycled residues of noise absorbers is 0.2 to 10 wt.%.

[0059] As described above, the recycled residues of noise absorbers can be contained in the sealant, for example and preferably in the form of particles obtained by comminution.

[0060] According to preferred embodiments of the invention, the particle size is 0.1 to 10 mm, particularly preferably 0.1 to 5 mm, most preferably, for example, 0.1 to 3 mm.

[0061] This achieves an optimal balance between flow behavior and sealing effect in the puncture site, especially after the (accidental) removal of the puncture object.

[0062] The particle size is determined using SEM ("scanning electron microscopy").

[0063] Particle size refers to the largest possible distance in the two-dimensional projection of a particle. For spherically shaped particles, this corresponds to the diameter.

[0064] According to the invention, the sealant is based on the crosslinking of a rubber and polyolefin. According to an advantageous and exemplary embodiment, the sealant is based on the crosslinking of a rubber and / or polyolefin.

[0065] The rubber used here is raw rubber, so the uncured sealant can contain both devulcanized rubber (see above) and unvulcanized rubber.

[0066] It is clear to the person skilled in the art that all of the above-mentioned components in the cross-linked sealant are present at least partially in chemically modified form, in particular as derivatives.

[0067] The (raw) rubber can be any type of rubber known to the person skilled in the art. A mixture of different rubbers is also conceivable.

[0068] According to a preferred embodiment of the invention, the rubber is natural rubber (NR) and / or butadiene rubber (BR) and / or isoprene rubber (IR) and / or styrene-butadiene rubber (SBR) and / or polychloroprene (CR) and / or butyl rubber (IIR) and / or bromobutyl rubber (BIIR) and / or chlorobutyl rubber (CIIR).

[0069] These rubber types are particularly well suited to the processing temperatures during the production of the sealant and later during application, especially in pneumatic vehicle tires.

[0070] Particularly preferred is at least butyl rubber (IIR). Butyl rubber is particularly suitable because it has a comparatively high level of airtightness.

[0071] According to the invention, the self-sealing tire sealant contains 40 to 80 wt.%, particularly preferably 50 to 75 wt.%, of at least one polyolefin. This achieves optimal flow behavior while simultaneously ensuring good manufacturability (processability) of the sealant.

[0072] The at least one polyolefin preferably has a number average molecular weight distribution Mn according to GPC of 400 to 2500 g / mol, particularly preferably 800 to 2500 g / mol, very particularly preferably 800 to 1600 g / mol, again preferably 1200 to 1600 g / mol, again particularly preferably 1200 to 1400 g / mol, for example 1300 g / mol.

[0073] A polyolefin with the mentioned ranges for the Mn is particularly suitable to create the desired flowability while simultaneously providing a sealing effect of the sealant in the event of a breakdown.

[0074] It is particularly preferred that the at least one polyolefin is at least one polybutene.

[0075] This adjusts the stickiness of the finished sealant and determines the flowability in the production process as well as the local strength of the finished sealant.

[0076] It can also be a mixture of two or more polybutenes, each with a Mn of 400 to 2500 g / mol, whereby the polybutenes can differ in Mn.

[0077] Suitable polybutenes, also called polyisobutenes, are available, for example, under the trade name Indopol ®< Polybutene from INEOS Capital Limited.

[0078] A mixture of at least one polybutene with at least one other polyolefin is also conceivable.

[0079] The sealant is preferably based on crosslinking by at least one crosslinker selected from the group consisting of, particularly preferably, polymethylol resin, divinylbenzene, and quinones. The quinone is preferably a quinone dioxime, for example, dibenzoylquinone dioxime or para-benzoquinone dioxime. Para-benzoquinone dioxime is particularly preferred.

[0080] The sealant is preferably based on crosslinking by at least one crosslinker in combination with a crosslinking initiator, wherein the crosslinking initiator is preferably selected from the group consisting of lead oxide and other metal oxides and peroxide compounds. The crosslinking initiator is a chemical compound that initiates the crosslinking of the sealant.

[0081] A peroxide compound is a chemical compound that contains at least one peroxide unit, i.e., -OO- (where O = oxygen). Multiple peroxides can also be used. The peroxide(s) are preferably selected from the group consisting of diaroyl peroxides, diacyl peroxides, and peroxy esters.

[0082] The crosslinking initiator can be added as a pure substance or in a mixture. In the case of a mixture, for example, 50 wt.% dibenzoyl peroxide in dibutyl maleate, only the amount of peroxide contained is included in the amount of crosslinking initiator, so accompanying substances such as dibutyl maleate are not included in the stated amounts of at least one crosslinking initiator.

[0083] The sealant may also contain other components, such as, in particular, further filler(s), tackifier(s), plasticizer(s), such as oil(s), and optionally further additives, such as, for example, color pigments and / or zinc oxide and / or sulfur.

[0084] According to a preferred embodiment of the invention, the sealant also contains at least one further filler, in particular at least one active filler.

[0085] The further filler can be any filler known to the person skilled in the art, such as, in particular, reinforcing fillers such as carbon black and / or silica, with particular reference to and preference being given to precipitated silicas which are known as fillers for tyre rubber mixtures.

[0086] Furthermore, other reinforcing and non-reinforcing fillers, in particular silicon oxide-based fillers such as silicates or sand, are conceivable, as well as possibly reinforcing fillers such as graphite and graphene and so-called "carbonsilica dual-phase fillers".

[0087] According to a preferred embodiment of the invention, the additional filler comprises at least one carbon black. This has the advantage of increasing the cohesion of the sealant and reducing its stickiness during the manufacturing process. At the same time, the sealant's stability and tear resistance are improved.

[0088] In principle, all types of carbon black known to the person skilled in the art can be considered as carbon blacks within the scope of the present invention.

[0089] According to an advantageous embodiment of the invention, a carbon black is used which has an iodine adsorption number according to ASTM D 1510 of 20 to 180 g / kg, particularly preferably 30 to 140 g / kg, and a DBP number according to ASTM D 2414 of 30 to 200 ml / 100 g, preferably 90 to 180 ml / 100 g, particularly preferably 110 to 180 ml / 100 g.

[0090] According to a further preferred embodiment of the invention, a carbon black of type N326 is used.

[0091] A mixture of two or more carbon blacks is also conceivable.

[0092] According to a further preferred embodiment of the invention, the further filler comprises at least one silica.

[0093] This achieves optimal reinforcement of the sealant and enables good viscosity control and adjustment. Furthermore, the use of at least one silica increases the sealant's cohesion and reduces its tackiness during the manufacturing process. At the same time, the sealant's in-place strength and tear properties are improved.

[0094] A mixture of two or more silicas is also conceivable.

[0095] The silicas can be those known to those skilled in the art and suitable as fillers for tire rubber compounds. Thus, for example, silicas of the type Ultrasil®< VN3 (trade name) from Evonik, as well as silicas with a comparatively low BET surface area (such as Zeosil®< 1115 or Zeosil®< 1085 from Solvay), as well as highly dispersible silicas, so-called HD silicas (e.g., Zeosil®< 1165 MP from Solvay) can be used.

[0096] Furthermore, a mixture of the further fillers mentioned is conceivable and preferred, such as in particular at least one industrial carbon black in combination with at least one silica, which also results in the advantages mentioned.

[0097] According to one embodiment, the amount of the at least one further filler is 0.1 to 15 wt.%, for example 5 to 10 wt.%, based on the total amount of sealant.

[0098] According to a further embodiment of the invention, no further filler is contained, ie 0 wt.% further filler.

[0099] According to advantageous embodiments, the sealant contains at least one tackifier, particularly in the case where the sealant does not already exhibit sufficient tackiness due to the components it contains, in particular the polymers. "Tackifier" is understood to mean, in principle, any substance that increases the tackiness of the sealant.

[0100] According to advantageous embodiments of the invention, the tackifier is at least one hydrocarbon resin.

[0101] It is clear to the person skilled in the art that hydrocarbon resins are polymers composed of monomers, whereby the hydrocarbon resin is formally composed of derivatives of the monomers by linking the monomers to one another.

[0102] In the context of the present application, the term "hydrocarbon resins" encompasses resins which contain carbon atoms and hydrogen atoms and may optionally contain heteroatoms, such as, in particular, oxygen atoms.

[0103] The hydrocarbon resin can be a homopolymer or a copolymer. In the present application, a homopolymer is defined as a polymer that, according to Römpp Online (excerpt from January 2, 2017, article last updated in August 2008), "is formed from monomers of only one type."

[0104] For the purposes of the present invention, a copolymer is understood to mean a polymer composed of several, i.e., two or more, different monomers. Therefore, for the purposes of the present invention, the hydrocarbon resin can also be, for example, a copolymer of three different monomers.

[0105] The monomers may be any monomers of hydrocarbon resins known to the person skilled in the art, such as aliphatic monomers, in particular aliphatic C 5 monomers, other unsaturated compounds which can be cationically polymerized, containing aromatics and / or terpenes and / or alkenes and / or cycloalkenes.

[0106] Preferred monomers are in particular C 5 and C 9 monomers.

[0107] The aromatics (aromatic monomers) can be, for example, alpha-methylstyrene and / or styrene and / or vinyltoluene and / or indene and / or coumarone and / or methylindene and / or methylcoumarone and / or phenol.

[0108] The aromatic monomers are preferably alpha-methylstyrene and / or styrene and / or vinyltoluene and / or indene and / or coumarone and / or methylindene and / or methylcoumarone.

[0109] According to Römpp Online, the term "olefins" is the "group name for acyclic and cyclic aliphatic hydrocarbons with one or more reactive C=C double bonds in the molecule, which are now better referred to as alkenes or cycloalkenes, and in a broader sense also as a name for their substituted derivatives..." For the purposes of the present invention, unsaturated terpenes, alkenes, and cycloalkenes are therefore summarized under the generic term "olefins."

[0110] The alkenes can be, for example, 1-butene and / or 2-butene and / or butadiene.

[0111] According to a preferred embodiment of the invention, the hydrocarbon resin is at least one aliphatic resin, i.e., a resin that does not contain any aromatic ring systems. Such a resin consists of 100 wt. % aliphatic monomers or their derivatives.

[0112] According to a further embodiment of the invention, the resin consists of 10 to 99 wt.%, preferably 50 to 99 wt.%, particularly preferably 70 to 99 wt.%, of aliphatic monomers and 1 to 90 wt.%, preferably 1 to 50 wt.%, particularly preferably 1 to 30 wt.% of aromatic monomers.

[0113] According to a preferred embodiment of the invention, the hydrocarbon resin is at least one resin composed of at least C5 monomers, known to those skilled in the art as a so-called C5 resin. This achieves particularly good sealant properties, in particular optimized flow behavior combined with good tackiness.

[0114] The aliphatic C5 monomers can be monomers of the C5 petroleum fraction, e.g., isoprene, and / or monomers of terpenes and / or cycloolefins and / or olefins, such as pentene. C5 means that these monomers are composed of five carbon atoms.

[0115] Furthermore, it is known to the person skilled in the art that the C 5 petroleum fraction may contain, in addition to aliphatic monomers having five carbon atoms, other aliphatic monomers (building blocks) with, for example, four, i.e. C 4 monomers, or six carbon atoms, C 6 monomers.

[0116] According to advantageous embodiments of the invention, the sealant contains 2 to 20 wt.% of at least one hydrocarbon resin as a tackifier. The amount of the at least one hydrocarbon resin is preferably 2 to 10 wt.%, particularly preferably 5 to 8 wt.%.

[0117] With such preferred and particularly preferred amounts, the tackiness and viscosity of the sealant are further optimized.

[0118] According to advantageous and exemplary embodiments of the invention, the sealant contains the following components in the following amounts: 0.2 to 25 wt.% of at least one recycled material 50 to 75 wt.% of at least one polyolefin, preferably at least one polybutene, and 2.0 to 20 wt.% of at least one tackifier and 9.0 to 15 wt.% of at least one rubber and 5.0 to 9 wt.% of at least one further filler and 0.4 to 0.8 wt.% of at least one crosslinker and 0.5 to 1.2 wt.% of at least one crosslinking initiator.

[0119] The information in wt.% refers to the total amount of sealant.

[0120] The tire sealant according to the invention can be produced by methods known in the prior art, wherein the at least one recycled material is mixed, for example, like other materials, in particular like fillers, in a possible precursor of the sealant.

[0121] A further subject of the present invention is a pneumatic vehicle tire which has the tire sealant according to the invention, including all the aforementioned embodiments, at least on the inner surface opposite the tread.

Claims

1. Self-sealing tyre sealant containing at least one recycled material, characterized in that the sealant is based on the crosslinking of a rubber and polyolefin, wherein the recycled material comprises at least one pyrolysis carbon black, wherein the pyrolysis carbon black has a content of polycyclic aromatic hydrocarbons (PAH) according to ASTM D-5186 of less than 50 ppm (mg / kg), particularly preferably less than 40 ppm, very particularly preferably less than 30 ppm, in turn preferably less than 10 ppm, wherein the amount of pyrolysis carbon black present is 2% to 10% by weight and wherein the tyre sealant contains 40% to 80% by weight of at least one polyolefin.

2. Tyre sealant according to Claim 1, characterized in that the recycled material is present in the form of particles, especially as inactive filler.

3. Tyre sealant according to either of the preceding claims, characterized in that the rubber is natural rubber (NR) and / or butadiene rubber (BR) and / or isoprene rubber (IR) and / or styrene-butadiene rubber (SBR) and / or polychloroprene (CR) and / or butyl rubber (IIR) and / or bromobutyl rubber (BIIR) and / or chlorobutyl rubber (CIIR).

4. Tyre sealant according to any of the preceding claims, characterized in that the polyolefin is at least one polybutene, wherein the polybutene has a number-average molecular weight distribution Mn according to GPC of 400 to 2500 g / mol.

5. Tyre sealant according to any of the preceding claims, characterized in that the recycled material comprises at least one regenerated rubber and / or reprocessed residues of sound deadenings, wherein the sound deadening comprises at least one material selected from the group consisting of polyurethane foams, glass wool, rock wool, textile loop pile products, textile deep pile products, textile fabric, nonwoven materials and cork.

6. Tyre sealant according to Claim 5, characterized in that the regenerated rubber is derived from end-of-life tyres and / or conveyor belts and / or from vulcanized scrap generated during production of technical rubber articles and / or pneumatic vehicle tyres.

7. Tyre sealant according to Claim 5 or 6, characterized in that the amount of regenerated rubber present is 10% to 25% by weight.

8. Tyre sealant according to Claim 5 or 6 or 7, characterized in that the regenerated rubber has a Mooney viscosity ML 1+4 at 100°C according to ASTM D1646 of 30 to 60 Mooney units.

9. Tyre sealant according to Claim 5, characterized in that the amount of reprocessed residues of sound deadenings is 0.2% to 10% by weight.

10. Pneumatic vehicle tyre which comprises the tyre sealant according to any of Claims 1 to 9 at least on the interior surface opposite the tread.