Self-sealing tire sealant, process for producing same, pneumatic vehicle tire containing said tire sealant, and use of a dispersion of a crosslinker in a plasticizer in producing a tire sealant

Abstract

The present invention relates to a self-sealing tire sealant, a method for its preparation, and a vehicle pneumatic tire comprising the tire sealant. The present invention further relates to the use of a dispersion of a crosslinking agent in a plasticizer in the preparation of a tire sealant. The crosslinking agent is added to the tire sealant during its preparation as a dispersion of at least one plasticizer and at least one crosslinking agent.

Description

[Technical Field]

[0001] The present invention relates to a self-sealing tire sealant, a process for making the same, and a pneumatic vehicle tire containing the tire sealant.

[0002] The present invention further relates to the use of a dispersion of a crosslinker in a plasticizer in the manufacture of a tire sealant. [Background technology]

[0003] A self-sealing pneumatic tire for a vehicle is known, for example, from the applicant's published patent application DE 102006059286 A1. There, a standard tire structure is subsequently provided with a sealant layer. The self-sealing sealant is a self-adhesive, viscous sealing compound that is applied in layers from the radially inner side in the protruding belt package area to the radially innermost tire layer, the generally airtight inner layer. The sealant layer can automatically seal punctures up to 5 millimeters in diameter. In the event of a puncture that penetrates the tread and penetrates the inner layer, the sealant completely surrounds the penetrating foreign object, sealing the inside from the environment and thus preventing compressed air from being lost from the tire. The vehicle driver does not need to immediately replace the defective tire with an equivalent replacement or emergency wheel.

[0004] The sealant is characterized by high airtightness, high adhesion and balanced flow properties.

[0005] Other self-sealing tire sealants are disclosed, for example, in WO 2020 / 169234 A1 and EP 3546202 B1. According to these documents, the sealant may contain cross-linking chemicals, such as cross-linking agents and cross-linking initiators. For such fine chemicals, the challenge is to achieve the best possible distribution thereof among the other components of the tire sealant.

[0006] For this purpose, EP 3546202 B1 discloses the addition of peroxides as crosslinking initiators to a mixture of organic solvents during the production of the sealant.

[0007] However, organic solvents have the disadvantage that they are volatile and have adverse health effects, particularly respiratory tract irritation.

[0008] Crosslinking agents, particularly quinonedioxime compounds such as p-benzoquinonedioxime, are typically added as powders in the production of prior art sealants, as disclosed, for example, in EP 3009260 A1. However, such powdered materials are explosive, making the handling and, therefore, the production of the sealant, much more difficult.

[0009] Powdered crosslinking agents such as p-benzoquinone dioxime also present significant challenges in dispersing them homogeneously, especially since they are typically present in small amounts relative to the total mass of the sealant.

[0010] Inhomogeneous distribution of the crosslinker in the sealant leads to inhomogeneous crosslinking and thus to undesirable properties, such as particularly poor creep behavior and low elasticity, which therefore have a negative impact on processability and sealing effectiveness. In the worst case, this may even result in the sealant leaking out of the tire. Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, the object of the present invention is to provide a self-sealing tire sealant containing at least one crosslinking agent, which exhibits improved creep behavior and higher elasticity. The tire sealant therefore exhibits better processability during manufacture and application in pneumatic vehicle tires, and achieves improved sealing effect therein. Undesirable leakage of the tire sealant from the tire is also avoided.

[0012] The tire sealant shall be produced in the most environmentally friendly and health-friendly manner possible, and shall be easier to manufacture.

[0013] It is a further related object of the present invention to provide a pneumatic vehicle tire including a tire sealant that overcomes the aforementioned problems of manufacturing and sealing effectiveness. [Means for solving the problem]

[0014] The object is achieved by an inventive tire sealant according to claim 1, by a process according to the invention for producing a tire sealant comprising at least one crosslinking agent, and by the use according to the invention of a dispersion of a crosslinking agent in a plasticizer in the production of a tire sealant comprising at least one crosslinking agent. The object is further achieved by a pneumatic vehicle tire according to the invention, which comprises a tire sealant according to the invention.

[0015] Surprisingly, it has been found that adding at least one crosslinking agent as a dispersion of at least one plasticizer and the at least one crosslinking agent during the production of a tire sealant significantly improves the distribution and homogeneity of the crosslinking agent in the tire sealant.The tire sealant according to the present invention exhibits higher elasticity and better creep behavior.The tire sealant also exhibits an improved sealing effect, which in particular prevents the sealant from leaking out of the tire.

[0016] The tire sealant according to the invention is characterized by increased durability, especially after a puncture has occurred.

[0017] The sealant according to the invention and the tire according to the invention are produced in a manner that is as environmentally friendly and health-friendly as possible.

[0018] For the sake of brevity, the terms "self-sealing tire sealant" and "sealant" are used synonymously unless specifically stated otherwise in the context of the present invention.

[0019] Furthermore, for the sake of brevity, the terms "pneumatic vehicle tire" and "tire" are used synonymously unless otherwise stated in the context of this invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The components of the sealant according to the present invention will now be described in more detail. Any indication including any preference level and embodiment feature of the sealant also applies to the process according to the present invention for producing the sealant and to the pneumatic vehicle tire according to the present invention, unless expressly stated otherwise, including in terms of the combination of any preference level and embodiment feature of the sealant with any preference level and embodiment feature of the process and tire. Furthermore, any indication including any preference level and embodiment feature also applies to the use according to the present invention.

[0021] All resulting combinations of features are encompassed by the present invention.

[0022] The present invention further includes all combinations of the various features of the sealant with the same or different levels of desirability.

[0023] The amounts given in % by weight of the components of the sealant are in each case based on the total amount of the sealant, unless expressly stated otherwise.

[0024] The amounts given in weight percent of the components of the dispersion, particularly for crosslinkers and plasticizers, are based on the total amount of the dispersion.

[0025] In accordance with the present invention, at least one crosslinking agent is added to the tire sealant during its manufacture as a dispersion of at least one plasticizer and the at least one crosslinking agent.

[0026] The tire sealant, crosslinker and plasticizer may in principle be of any type suitable for pneumatic vehicle tires and known to those skilled in the art.

[0027] The plasticizer may be any plasticizer known to those skilled in the art, in particular oils, such as vegetable oils, especially rapeseed oil, aromatic, naphthenic, or paraffinic mineral oil plasticizers, such as MES (light extractive solvates) or paraffin oil (white mineral oil), preferably having a polycyclic aromatics content of less than 3% by weight according to the IP 346 method, or RAE (residual aromatic extract), or TDAE (treated distillate aromatic extract), or rubber-to-liquid oil (RTL) or biomass-to-liquid oil (BTL). Mineral oil is particularly preferred as the plasticizer.

[0028] The plasticizer of the dispersion is preferably an oil, which is preferably selected from the group consisting of paraffin oil, MES (mild emulsion solvate) (paraffinic MES is particularly preferred), and vegetable oil (rapeseed oil is particularly preferred).

[0029] The oil as a plasticizer realizes a particularly good distribution of the crosslinking agent in the plasticizer, and therefore the dispersion in the tire sealant.At the same time, oils, especially those selected from the group consisting of paraffin oil, MES (mild solvate) (particularly preferred is paraffinic MES) and vegetable oil (particularly preferred is rapeseed oil), are particularly suitable for such tire sealants, and are characterized by excellent properties in terms of sealing effect, flow behavior and adhesion.

[0030] Oils, especially those selected from the group consisting of paraffin oil, MES (mild solvents) (paraffinic MES is especially preferred), and vegetable oils (rapeseed oil is especially preferred), are also relatively environmentally friendly, do not pose adverse health effects, and do not tend to evaporate quickly like organic solvents.

[0031] In a particularly advantageous embodiment, the oil is a paraffinic mineral oil, in particular paraffin oil.

[0032] The crosslinking agent is preferably selected from the group consisting of quinonedioxime compounds, quinone, divinylbenzene, and 1,4-dinitrosobenzene, with quinonedioxime compounds, especially p-benzoquinonedioxime (QDO), being particularly preferred.

[0033] This makes it possible to achieve particularly good cross-linking of the sealant and therefore excellent properties in terms of sealing effect and flow behavior.

[0034] The dispersion is 50% to 80% by weight of a crosslinker; 20% to 50% by weight of plasticizer It is preferable that the formula includes:

[0035] The dispersion may optionally contain other ingredients, such as chalk. The dispersion preferably contains up to 5% by weight of other ingredients.

[0036] In an advantageous embodiment, the dispersion is free of other components, ie contains 0% by weight of other components.

[0037] The amounts listed in weight percent are based on the total weight of the dispersion.

[0038] The dispersion is 60% to 70% by weight, for example 65% by weight, of a crosslinker; 30% to 40% by weight, e.g., 35% by weight, of a plasticizer, and optionally up to 5% by weight of other ingredients, e.g., chalk. It is particularly preferred that the composition contains:

[0039] In an advantageous embodiment, the dispersion is free of other components, ie contains 0% by weight of other components.

[0040] The amounts listed in weight percent are based on the total weight of the dispersion.

[0041] In a preferred embodiment, the dispersion comprises 60% to 70% by weight, for example 65% by weight, of p-benzoquinone dioxime (QDO); 30% to 40% by weight, for example 35% by weight, of an oil, preferably a paraffinic mineral oil, in particular paraffin oil Includes:

[0042] In an advantageous embodiment, the dispersion is free of other components, ie contains 0% by weight of other components.

[0043] The amounts listed in weight percent are based on the total weight of the dispersion.

[0044] The component amounts of the dispersions described are understood to equal 100% by weight and are selected as such.

[0045] The object underlying the present invention is particularly easily achieved by the preferred and especially preferred amounts of crosslinker and plasticizer.

[0046] In particular, there is a homogeneous distribution of the crosslinking agent in the sealant, which is characterized by a high elasticity as a result of the improved degree and homogeneity of crosslinking.

[0047] The self-sealing tire sealant preferably has d) 0.5% to 7% by weight, particularly preferably 1.5% to 5% by weight, of a dispersion of at least one plasticizer and at least one crosslinker, the amounts in % by weight being based here on the total amount of the tire sealant.

[0048] It is preferred if the self-sealing tire sealant is based on the crosslinking of at least one polyolefin and / or rubber with at least one crosslinking agent.

[0049] This ensures a particularly high compatibility of the sealant with pneumatic vehicle tires, in particular with their inner layers, and at the same time, such sealants can be particularly easily adapted to the different requirements of different types of tires, thereby providing in each case unique characteristics in terms of sealing effect, flow behavior and adhesion.

[0050] In an advantageous embodiment, the sealant comprises at least one rubber.

[0051] The rubber may be selected from any type of rubber known to those skilled in the art. Mixtures of different rubbers are also contemplated.

[0052] In 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 black butyl rubber (CIIR) and / or silicone rubber.

[0053] These types of rubbers are particularly well suited to the processing temperatures during the manufacture of the sealant and subsequent use, particularly in pneumatic vehicle tires.

[0054] It is particularly preferred if the self-sealing tire sealant comprises at least one butyl rubber (IIR). As known to those skilled in the art, butyl rubber is a copolymer of isobutene and isoprene.

[0055] The butyl rubber present in the sealant preferably has an isoprene content of 0.5 to 5 mol %. Those skilled in the art will recognize that the isoprene content also represents the proportion of unsaturated carbon-carbon bonds in the polymer chains of the butyl rubber. The higher the isoprene content, the greater the crosslinking capacity of the rubber in the sealant, and thus of the polymer matrix, due to the increased proportion of unsaturated bonds.

[0056] In a preferred embodiment, the sealant comprises a butyl rubber whose isoprene content is 2.3 to 5.0 mol %.

[0057] This relatively high isoprene percentage allows for a higher level of cross-linking and improved gas tightness.

[0058] At the same time, this may require increased amounts of crosslinking agent and optionally crosslinking initiator, especially if the distribution of the crosslinking chemicals is inhomogeneous, and / or the increased isoprene content of butyl rubber may result in a more inhomogeneous distribution of the crosslinking agent.

[0059] Due to the dispersion of crosslinker and plasticizer and the resulting more homogeneous distribution of crosslinker in the sealant, the present invention also makes it possible to utilize butyl rubber with an isoprene content of 2.3 to 5.0 mol % and its associated benefits.

[0060] The present invention therefore makes it possible to exploit the full crosslinking ability realized by the presence of butyl rubber having an isoprene content of 2.3 to 5.0 mol %.

[0061] A more homogeneous distribution in the dispersion means that it may not be necessary to use larger amounts of cross-linker, or the amount of cross-linker can be matched exactly to the isoprene content, so that neither cross-linker nor unsaturated bonding sites on the polymer chains are wasted.

[0062] The self-sealing tire sealant preferably comprises: a) It contains 9% by weight to 50% by weight, particularly preferably 12% by weight to 50% by weight, of at least one rubber, the rubber being preferably butyl rubber (IIR).

[0063] In a particularly preferred embodiment, the sealant a) comprises 20.5% to 40% by weight, particularly preferably 20.5% to 29.5% by weight, of at least one butyl rubber.

[0064] The sealant therefore has a particularly good property profile, including sealing effect, flow behavior, and adhesion, and in particular very good airtightness. The relatively large amount of butyl rubber in the sealant simultaneously has the advantage that accelerated crosslinking and improved airtightness are achieved when using butyl rubber with an isoprene content of 2.3 to 5.0 mol %.

[0065] In an advantageous embodiment, the sealant comprises at least one polyolefin.

[0066] This allows for optimum flow behavior and the associated high manufacturing efficiency (processability) of the sealant.

[0067] 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, also preferably 1200 to 1600 g / mol, also particularly preferably 1200 to 1400 g / mol, for example 1300 g / mol.

[0068] Polyolefins having Mn in the above range are particularly suitable for achieving the desired flowability and sealing effect of the sealant when a puncture occurs.

[0069] The term "polyolefins" is understood to mean in particular polyalkenes obtained in particular by polymerization of unbranched alkenes, such as polyethylene, polypropylene, polybutene, and polyisobutene.

[0070] The at least one polyolefin is particularly preferably at least one polybutene.

[0071] This establishes the tack of the finished sealant and determines the local consistency of the finished sealant as well as its flowability during the manufacturing process.

[0072] The at least one polyolefin may also be a mixture of two or more polybutenes, each having a Mn of 400 to 2500 g / mol, and these polybutenes may differ in their Mn.

[0073] Suitable polybutenes, also known as polybutylenes, are available, for example, from INEOS Capital Limited under the trade name Indopol® polybutene.

[0074] Mixtures of at least one polybutene with at least one other polyolefin are also contemplated.

[0075] The self-sealing tire sealant preferably comprises: b) Contains 11% to 80% by weight of at least one polyolefin, the polyolefin being preferably polybutene.

[0076] In a particularly advantageous embodiment, the sealant comprises b) 14.5% to 65% by weight of at least one polyolefin.

[0077] The sealant may further comprise components such as crosslinking initiators, fillers, tackifiers, additional plasticizers, such as oils, and optionally other additives, such as color pigments and / or zinc oxide and / or sulfur, among others.

[0078] In a preferred embodiment of the invention, the sealant comprises at least one filler, in particular at least one active filler.

[0079] The filler is preferably selected from carbon black and silicon dioxide.

[0080] The silicon dioxide is preferably amorphous silicon dioxide, such as precipitated silica, also known as precipitated silicon dioxide. However, it is also possible to use, for example, finely divided silicon dioxide instead.

[0081] The filler is particularly preferably carbon black.

[0082] Suitable carbon blacks include all types of carbon black known to those skilled in the art. It is preferred if the carbon black is selected from technical carbon black and pyrolytic carbon black, with technical carbon black being more preferred.

[0083] This has the advantage of improving the cohesion of the sealant and reducing its stickiness during the manufacturing process, while also improving the sealant's stability and tear properties.

[0084] In an advantageous embodiment of the present invention, carbon black is used which has an iodine adsorption number according to ASTM D1510 of 20 to 180 g / kg, particularly preferably 30 to 140 g / kg, and a DBP number according to ASTM D2414 of 30 to 200 mL / 100 g, preferably 90 to 180 mL / 100 g, particularly preferably 110 to 180 mL / 100 g.

[0085] In another preferred embodiment of the present invention, N326 type carbon black is used.

[0086] Mixtures of two or more carbon blacks are also contemplated.

[0087] The self-sealing tire sealant preferably comprises: c) 2% to 15% by weight of at least one filler, the filler being preferably selected from carbon black and silicon dioxide, with carbon black being particularly preferred.

[0088] With the above amounts, the sealant exhibits very good constancy due to optimized creep behavior, very good sealing effect and very good tear properties.

[0089] In a preferred embodiment of the present invention, the sealant comprises at least one crosslinking initiator.

[0090] A crosslinking initiator is a chemical that initiates the crosslinking of the sealant.

[0091] The at least one crosslinking initiator is preferably selected from the group consisting of lead oxides, other metal oxides, and peroxides, with peroxides being particularly preferred.

[0092] The peroxide is preferably selected from the group consisting of diaroyl peroxides, diacyl peroxides, and peroxyesters.

[0093] The crosslinking initiator may be added either as a pure substance or in admixture with a stabilizer such as dibutyl maleate.

[0094] For example, a mixture of 50% by weight dibenzoyl peroxide and 50% by weight dibutyl maleate is contemplated.

[0095] It is further conceivable to add a crosslinking initiator to the liquid in a weight fraction of 35% to 40% by weight, as described in EP 3546202B.

[0096] In all mixtures, only the amount of peroxide present is included in the stated amount of crosslinking initiator in the sealant, i.e., the stated amount of at least one crosslinking initiator does not include any accompanying materials such as dibutyl maleate or liquids.

[0097] The self-sealing tire sealant preferably comprises: e) 0.5% to 8% by weight, preferably 0.5 to 6% by weight, of at least one crosslinking initiator Includes.

[0098] The combination of the crosslinker and crosslink initiator in the amounts described above provides a particularly effective tire sealant that seals quickly in the event of a puncture and can be further optimized for tires having different internal pressures.

[0099] In an advantageous embodiment, the sealant comprises at least one adhesive, especially if the sealant does not already have sufficient adhesion due to the components present, in particular the polymers. The term "adhesive" is understood to mean in principle any substance that increases the adhesion of the sealant.

[0100] In an advantageous embodiment of the invention, the tackifier is at least one hydrocarbon resin.

[0101] As will be appreciated by those skilled in the art, hydrocarbon resins are polymers made up of monomers, where the hydrocarbon resins are formally made up of derivatives of the monomers by linking them together.

[0102] The term "hydrocarbon resin" in the context of this application includes resins containing carbon and hydrogen atoms, and optionally heteroatoms, such as oxygen atoms in particular.

[0103] The hydrocarbon resin is preferably selected from the group consisting of phenolic resins, further aromatic resins, preferably alpha-methylstyrene-styrene resins and / or chroman-indene resins, aliphatic resins, preferably C5 resins, and rubber resins, in particular rosin and / or balsam resins. The adhesive is particularly preferably a fatty acid C5 resin.

[0104] The self-sealing tire sealant preferably comprises: f) 1.5% to 10% by weight of at least one adhesive Includes.

[0105] Such an amount optimizes the adhesion and viscosity of the sealant.

[0106] Self-sealing tire sealant g) It is preferred if it also contains up to 1.1% by weight, particularly 0.1 to 1.1% by weight, of zinc oxide.

[0107] Zinc oxide improves the stability of the crosslinking sites in terms of lifetime and with respect to heat.

[0108] In an advantageous embodiment, the self-sealing tire sealant also comprises at least one additional plasticizer, depending on the composition of its other components, in order to further optimize the sealant, especially with regard to its processability.

[0109] The additional plasticizer may be any plasticizer known to those skilled in the art, and is preferably an oil, in particular an aromatic, naphthenic, or paraffinic mineral oil plasticizer, such as MES (Mild Extraction Solvates) or RAE (Residual Aromatic Extract) or TDAE (Distillate Aromatic Extract) or rubber-to-liquid oil (RTL) or biomass-to-liquid oil (BTL) having a polycyclic aromatic content of less than 3% by weight according to the IP 346 method. Mineral oil is particularly preferred as the plasticizer.

[0110] If a mineral oil is used, it is preferably selected from the group consisting of DAE (Distillate Aromatic Extract), RAE (Residual Aromatic Extract), TDAE (Treated Distillate Aromatic Extract), MES (Mild Extraction Solvate), and naphthenic oil.

[0111] It is particularly preferred to use MES (mild extractive solvates) as additional plasticizer, with paraffinic MES (mild extractive solvates) also being particularly preferred here.

[0112] In a preferred embodiment, the self-sealing tire sealant comprises: h) 0.5% to 8% by weight of oil as an additional plasticizer Includes.

[0113] In a further preferred embodiment, the self-sealing tire sealant does not contain any additional plasticizers other than those already present in the dispersion, i.e., 0 wt. % additional plasticizers.

[0114] In an advantageous embodiment, the addition of a dispersion of crosslinker in a plasticizer according to the invention therefore makes it possible at the same time to avoid the addition of additional plasticizer.

[0115] This eliminates the need to measure and add additional ingredients.

[0116] The self-sealing tire sealant also contains up to 1% by weight of sulfur, especially 0.1% to 1.0% by weight.

[0117] This improves the high temperature stability of the environmental site.

[0118] In a preferred embodiment, the sealant therefore comprises the following components: butyl rubber, polyolefin, filler, a dispersion of crosslinker and plasticizer, a crosslinking initiator, a tackifier, a filler, and optionally further plasticizers, zinc oxide, and sulfur. Includes:

[0119] All indications and preferred characteristics for any preference level apply to ingredient types and amounts.

[0120] In particularly preferred embodiments, the sealant comprises components according to the specified characteristics a) to i) in combination with one another. All indications and preferred characteristics at all preference levels apply to types and amounts of components.

[0121] In a particularly advantageous embodiment of the present invention, the self-sealing tire sealant comprises at least the following components: a1) 12% to 22% by weight of at least one rubber, preferably a butyl rubber, the isoprene content of the butyl rubber preferably being 0.5 to 2.3 mol %; b1) 58% to 78% by weight of at least one polyolefin; c1) 4% to 8% by weight of at least one filler; d1) a dispersion of 0.5% to 2.5% by weight of at least one plasticizer and at least one crosslinker, the dispersion comprising 50% to 80% by weight of crosslinker and 20% to 50% by weight of plasticizer; e1) 1.5% to 3.5% by weight of at least one crosslinking initiator; f1) 1.5 wt% to 4.5 wt% of at least one adhesive; Includes:

[0122] The sealant also: g1) 0.3 wt% to 1.1 wt% zinc oxide, h1) 0.5% by weight to 2.5% by weight of oil; Optionally, i1) up to 0.6% by weight of sulfur, in particular 0.1% to 0.6% by weight of sulfur; Includes.

[0123] Such sealants having compositions a1) to i1) are particularly suitable for passenger car tires.

[0124] One embodiment of the present invention is a passenger tire comprising a sealant having compositions a1) to i1) on at least the inner surface opposite the threads.

[0125] The above characteristics regarding type and, optionally, amount, including all embodiments and preference levels, also apply to components a1) to i1).

[0126] For example, among the component "b1) 58% to 78% by weight of at least one polyolefin," the polyolefin is preferably polybutene.

[0127] In another particularly advantageous embodiment of the present invention, the self-sealing tire sealant comprises the following components: a2) 13.5% to 29.5% by weight, preferably 20.5% to 29.5% by weight, of at least one rubber, preferably a butyl rubber, the butyl rubber having an isoprene content preferably of 0.5 to 2.3 mol%, b2) 47% to 77% by weight of at least one polyolefin; c2) 2.5 wt.% to 7.5 wt.% of at least one filler; d2) 1% to 4% by weight of a dispersion of at least one plasticizer and at least one crosslinker, the dispersion comprising 50% to 80% by weight of crosslinker and 20% to 50% by weight of plasticizer; e2) 2% to 4% by weight of at least one crosslinking initiator; f2) 1.5 wt% to 4.5 wt% of at least one adhesive; Includes.

[0128] This sealant further: Optionally, g2) up to 1.0 wt. % zinc oxide, in particular 0.1 wt. % to 1.0 wt. % zinc oxide; Optionally, h2) up to 4 wt. % of oil, in particular 0.5 wt. % to 4 wt. % of oil; Optionally, i2) up to 1.0 wt. % sulfur, in particular 0.1 wt. % to 1.0 wt. % sulfur; and It is preferable that the formula includes:

[0129] Such sealants with compositions a2) to i2) are particularly suitable for van tyres.

[0130] One embodiment of the present invention is a van tire comprising a sealant having compositions a2) to i2) at least on the inner surface opposite the threads.

[0131] The above characteristics regarding type and, optionally, amount, including all embodiments and levels of preference, also apply to components a2) to i2).

[0132] In another particularly advantageous embodiment of the present invention, the self-sealing tire sealant comprises at least the following components: a3) 15.5% to 35.5% by weight of at least one rubber, preferably a butyl rubber, the butyl rubber preferably having an isoprene content of 0.5 to 5 mol %; b3) 40% to 70% by weight of at least one polyolefin; c3) 2.5 wt.% to 7.5 wt.% of at least one filler; d3) a 2% to 5% by weight dispersion of at least one plasticizer and at least one crosslinker, the dispersion comprising 50% to 80% by weight crosslinker and 20% to 50% by weight plasticizer; e3) 2.5% to 5.5% by weight of at least one crosslinking initiator; f3) 1.5 wt% to 5.5 wt% of at least one adhesive; Includes.

[0133] This sealant further: Optionally, g3) up to 1.0 wt. % zinc oxide, in particular 0.1 wt. % to 1.0 wt. % zinc oxide; Optionally, h3) up to 5 wt. %, in particular 0.5 wt. % to 5 wt. % of oil; and Optionally, i3) up to 1.0 wt. % sulfur, in particular 0.1 wt. % to 1.0 wt. % sulfur; and It is preferable that the formula includes:

[0134] Such sealants having compositions a3) to i3) are particularly suitable for truck tires.

[0135] One embodiment of the present invention is a truck tire comprising a sealant having compositions a3) to i3) at least on the inner surface opposite the threads.

[0136] The above characteristics regarding type and, optionally, amount, including all embodiments and preference levels, also apply to components a3) to i3).

[0137] In another particularly advantageous embodiment of the present invention, the self-sealing tire sealant comprises at least the following components: a4) 26% to 50% by weight of at least one rubber, preferably a butyl rubber, the butyl rubber preferably having an isoprene content of 0.5 to 5 mol%, b4) 14.5% to 54.5% by weight of at least one polyolefin; c4) 3 wt.% to 9 wt.% of at least one filler; d4) 3% to 7% by weight of a dispersion of at least one plasticizer and at least one crosslinker, the dispersion comprising 50% to 80% by weight of crosslinker and 20% to 50% by weight of plasticizer; e4) 4% to 8% by weight of at least one crosslinking initiator; f4) 2 wt% to 7 wt% of at least one adhesive; Includes.

[0138] This sealant further: Optionally, g4) up to 1.0 wt. % zinc oxide, in particular 0.1 wt. % to 1.0 wt. % zinc oxide; h4) 2% to 8% by weight of oil; Optionally, i4) up to 1.0 wt. % sulfur, in particular 0.1 wt. % to 1.0 wt. % sulfur; and It is preferable that the formula includes:

[0139] Such sealants with compositions a4) to i4) are particularly suitable for agricultural or construction site tyres, such as agricultural tractors, self-propelled harvesters, trailers, wheel loaders or excavators.

[0140] One embodiment of the present invention is an agricultural or construction tire comprising a sealant having compositions a4) to i4) at least on the inner surface opposite the threads.

[0141] The above characteristics regarding type and, optionally, also amount, including all embodiments and preference levels, also apply to components a4) to i4).

[0142] In addition, as repeatedly stated above, all other indications regarding these characteristics also apply to compositions a1)-i1), a2)-i2), a3)-i3), and a4)-i4).

[0143] This therefore applies in particular to all of the above-mentioned embodiments in which the polyolefin is polybutene, the filler is carbon black, the tackifier is a hydrocarbon resin, the crosslinking initiator is a peroxide, etc.

[0144] This is especially true for all of the above embodiments in which the plasticizer is preferably an oil, and particularly preferably selected from the group consisting of paraffin oil, MES (mild extractive solvates), with paraffinic MES being particularly preferred, and vegetable oil, with rapeseed oil being particularly preferred.

[0145] In a particularly advantageous embodiment, the oil is a paraffinic mineral oil, in particular paraffin oil.

[0146] This is particularly true for all of the foregoing embodiments in which the cross-linking agent is selected from the group consisting of quinonedioxime compounds, quinone, divinylbenzene, and 1,4-dinitrosobenzene, with quinonedioxime compounds, and in particular, p-benzoquinonedioxime (QDO), being particularly preferred.

[0147] The process according to the invention for producing a self-sealing tire sealant comprising at least one crosslinking agent comprises at least the following process steps: X1) producing or providing a dispersion of at least one crosslinker in at least one plasticizer; X2) providing further components, such as preferably at least one polyolefin and / or at least one rubber, in one or more process steps; X3) adding the dispersion from step X1) to the ingredients of step X2); Includes:

[0148] The dispersion of step X1) is commercially available, for example a dispersion of 60% to 65% by weight of p-benzoquinonedioxime and 35% to 40% by weight of oil, optionally containing up to 5% by weight of chalk, available from LORD Germany Feinchemie GmbH under the trade name QDO 65MK.

[0149] If the dispersion of step X1) is not commercially available, it can be prepared as follows. X01) providing at least one crosslinker, the crosslinker being selected from the group consisting of quinonedioxime compounds, quinone, divinylbenzene, and 1,4-dinitrosobenzene, with quinonedioxime compounds and, in particular, p-benzoquinonedioxime (QDO) being particularly preferred; X02) providing at least one plasticizer, preferably selected from the group consisting of paraffin oil, MES (mild extract solvates), with paraffinic MES being particularly preferred, and vegetable oil, with rapeseed oil being particularly preferred; X03) The crosslinker from step X01) is dispersed intensively with the plasticizer from step X02) to obtain a dispersion of at least one crosslinker in at least one plasticizer.

[0150] In an exemplary and advantageous embodiment of the invention, process step X2) comprises at least the following process steps: X2-1) mixing at least one rubber with at least one filler to form a masterbatch; X2-2) mixing the masterbatch with at least one polyolefin to produce component A; X2-3) mixing at least one crosslinking initiator with at least one polyolefin to form component B; X2-4) mixing component A and component B to form a tire sealant; Includes.

[0151] The addition of the dispersion according to step X3) is preferably carried out during step X2-1).

[0152] The mixing of ingredients in all of the steps is carried out in equipment known to those skilled in the art.

[0153] The mixing of step X2-2) is preferably carried out in an extruder, preferably a twin-screw extruder.

[0154] The mixing in step X2-3) is preferably carried out in a mixing tank.

[0155] The mixing in step X2-4) is preferably carried out in a static mixer.

[0156] As previously mentioned, the present invention further provides a pneumatic vehicle tire comprising a tire sealant according to the present invention, the tire sealant including all of the above indicia on at least the inner surface opposite the treads.

[0157] As mentioned above, the present invention further provides the use of a dispersion of at least one crosslinker, preferably p-benzoquinone dioxime, in at least one plasticizer, preferably selected from the group consisting of paraffin oil, MES (mild extractive solvate), with paraffinic MES being particularly preferred, and vegetable oil, with rapeseed oil being particularly preferred, in the manufacture of a self-sealing tire sealant.

[0158] The present invention will now be more particularly described with reference to exemplary embodiments.

[0159] Table 1 shows the hysteresis and creep behavior of the inventive sealant E1 and the comparative sealant V1 using average loss tangent values ​​at 100°C.

[0160] The amounts of the components shown are specified in weight percent. E1 was prepared using the process according to steps X1) to X3) described above, including X2-1) to X2-4), with the dispersion added in step X2-1). V1 was prepared according to steps X2-1) to X-2-4), with the crosslinker added in step X2-1).

[0161] The following methods were used to characterize the properties: Average loss tangent by frequency transmission at 100℃ Vertical creep: Measured creep length: Length in millimeters (mm) of creep-inducing sample after vertical creep at 125°C

[0162] The loss tangent and creep length values ​​were determined by averaging two samples each.

[0163] [Table 1]

[0164] As is evident from Table 1, the sealant of the present invention results in a lower loss tangent at 100°C.

[0165] E1 also exhibits improved, i.e., reduced, creep behavior.

[0166] This improves the processability of the sealant during its manufacture and application in pneumatic vehicle tires, while also preventing, or at least significantly reducing, the risk of unwanted bleeding of the sealant from the tire. While this application is directed to the invention set forth in the claims, the disclosure of this application also includes: 1. A self-sealing tire sealant comprising at least one crosslinking agent, wherein said at least one crosslinking agent is added to said tire sealant during its manufacture as a dispersion of at least one plasticizer and said at least one crosslinking agent. 2. The self-sealing tire sealant according to claim 1, wherein the plasticizer is preferably an oil selected from the group consisting of paraffin oil, MES (mild extract solvate) (paraffinic MES is particularly preferred), and vegetable oil (rapeseed oil is particularly preferred). 3. The crosslinking agent is selected from the group consisting of quinonedioxime compounds, quinone, divinylbenzene, and 1,4-dinitrosobenzene, and is particularly The self-sealing tire sealant according to 1 or 2 above, wherein p-benzoquinone dioxime is particularly preferred. 4. The self-sealing tire sealant described in any one of items 1 to 3, wherein the dispersion contains 50% to 80% by weight, preferably 60% to 70% by weight, of a crosslinker and 20% to 50% by weight, preferably 30% to 40% by weight, of a plasticizer, the amounts shown in % by weight being based on the total amount of the dispersion. 5. The self-sealing tire sealant according to any one of items 1 to 4, characterized by being based on crosslinking between at least one polyolefin and / or rubber and the at least one crosslinking agent. 6. a) 9% by weight to 50% by weight, preferably 12% by weight to 50% by weight, particularly preferably 20.5% by weight to 40% by weight of at least one rubber, preferably butyl rubber (IIR), the butyl rubber preferably having an isoprene content of 0.5 to 5 mol%. 6. The self-sealing tire sealant according to any one of the above items 1 to 5, comprising: 7. b) 11% to 80% by weight, preferably 14.5% to 65% by weight, of at least one polyolefin, preferably polybutene 7. The self-sealing tire sealant according to any one of the above items 1 to 6, comprising: 8. c) 2% to 15% by weight of at least one filler, preferably selected from carbon black and silicon dioxide, with carbon black being a particularly preferred filler. 8. The self-sealing tire sealant according to any one of the above items 1 to 7, comprising: 9. d) 0.5% to 7% by weight, preferably 1.5% to 5% by weight, of said dispersion of at least one plasticizer and said at least one crosslinking agent. 9. The self-sealing tire sealant according to any one of the above items 1 to 8, comprising: 10. e) 0.5% to 8% by weight, preferably 0.5% to 6% by weight, of at least one crosslinking initiator, preferably selected from the group consisting of lead oxide, other metal oxides, and peroxides, with peroxides being particularly preferred. The self-sealing tire sealant according to any one of the above items 1 to 9, characterized by comprising: 11. f) 1.5% to 10% by weight of at least one adhesive, preferably a phenolic resin, a further fragrance resin, preferably an alpha-methylstyrene resin, and / or a chroman-indene resin, a fatty acid resin, preferably C 5 Adhesives which are hydrocarbon resins selected from the group consisting of resins and rubber resins, in particular rosin and / or balsam resins The self-sealing tire sealant according to any one of the above items 1 to 10, characterized by comprising: 12. Contains at least the following ingredients: a1) 12% to 22% by weight of at least one rubber, preferably a butyl rubber, the butyl rubber preferably having an isoprene content of 0.5 to 2.5 mol %; b1) 58% to 78% by weight of at least one polyolefin; c1) 4% to 8% by weight of at least one filler; d1) 0.5% to 2.5% by weight of the dispersion of at least one plasticizer and the at least one crosslinker, wherein the dispersion is 50% to 80% by weight of the crosslinker and 20% to 50% by weight of the plasticizer; e1) 1.5% to 3.5% by weight of at least one crosslinking initiator; f1) 1.5 wt% to 4.5 wt% of at least one adhesive; 12. The self-sealing tire sealant according to any one of the above items 1. to 11., comprising: 13. Contains at least the following ingredients: a2) 13.5% to 29.5% by weight, preferably 20.5% to 29.5% by weight, of at least one rubber, preferably a butyl rubber, the butyl rubber preferably having an isoprene content of 0.5 to 2.5 mol%, b2) 47% to 77% by weight of at least one polyolefin; c2) 2.5 wt.% to 7.5 wt.% of at least one filler; d2) a dispersion of 1% to 4% by weight of at least one plasticizer and the at least one crosslinker, the dispersion comprising 50% to 80% by weight of crosslinker and 20% to 50% by weight of plasticizer; e2) 2% to 4% by weight of at least one crosslinking initiator; f2) 1.5 wt% to 4.5 wt% of at least one adhesive; 12. The self-sealing tire sealant according to any one of the above items 1. to 11., comprising: 14. Contains at least the following ingredients: a3) 15.5% by weight to 35.5% by weight of at least one rubber, preferably a butyl rubber, the butyl rubber preferably having an isoprene content of 0.5 to 5 mol %; b3) 40% to 70% by weight of at least one polyolefin; c3) 2.5 wt.% to 7.5 wt.% of at least one filler; d3) a dispersion of 2% to 5% by weight of at least one plasticizer and the at least one crosslinker, the dispersion comprising 50% to 80% by weight of crosslinker and 20% to 50% by weight of plasticizer; e3) 2.5% to 5.5% by weight of at least one crosslinking initiator; f3) 1.5 wt% to 5.5 wt% of at least one adhesive; 12. The self-sealing tire sealant according to any one of the above items 1. to 11., comprising: 15. Contains at least the following ingredients: a4) 26% to 50% by weight of at least one rubber, preferably a butyl rubber, the butyl rubber preferably having an isoprene content of 0.5 to less than 5 mol%, b4) 14.5% to 54.5% by weight of at least one polyolefin; c4) 3 wt.% to 9 wt.% of at least one filler; d4) 3% to 7% by weight of said dispersion of at least one plasticizer and said at least one crosslinker, said dispersion comprising 50% to 80% by weight of crosslinker and 20% to 50% by weight of plasticizer; e4) 4% to 8% by weight of at least one crosslinking initiator; f4) 2 wt% to 7 wt% of at least one adhesive; 12. The self-sealing tire sealant according to any one of the above items 1. to 11., comprising: 16. A process for producing a self-sealing tire sealant containing at least one crosslinking agent, particularly a self-sealing tire sealant containing the tire sealant described in any one of the above items 1 to 15, comprising at least the following process steps: X1) producing or providing a dispersion of at least one crosslinker in at least one plasticizer; X2) providing additional components, such as preferably at least one polyolefin and / or at least one rubber, in one or more process steps; X3) adding the dispersion from step X1) to the ingredients of step X2); A process involving: 17. A pneumatic vehicle tire comprising the tire sealant according to any one of items 1 to 15 above or the tire sealant produced by the process according to item 16 above, at least on the inner surface opposite the threads. 18. Use of a dispersion of at least one crosslinking agent, preferably p-benzoquinone dioxime, in at least one plasticizer, preferably selected from the group consisting of paraffin oil, MES (mild extractive solvate), with paraffinic MES being particularly preferred, and vegetable oil, with rapeseed oil being particularly preferred, in the manufacture of a self-sealing tire sealant.

Claims

1. 1. A self-sealing tire sealant comprising at least one crosslinking agent, wherein the at least one crosslinking agent is added to the tire sealant during its preparation as a dispersion of at least one plasticizer and the at least one crosslinking agent; The dispersion comprises 50% to 80% by weight of a crosslinker and 20% to 50% by weight of a plasticizer, the amounts in weight percent given being based on the total amount of the dispersion. Self-sealing tire sealant.

2. 2. The self-sealing tire sealant of claim 1, wherein the plasticizer is an oil.

3. A self-sealing tire sealant as described in claim 1, characterized in that the plasticizer is an oil selected from the group consisting of paraffin oil, MES and vegetable oil.

4. 3. The self-sealing tire sealant according to claim 1, wherein the cross-linking agent is selected from the group consisting of quinone dioxime compounds, quinone, divinylbenzene, and 1,4-dinitrosobenzene.

5. 3. A self-sealing tire sealant according to claim 1 or 2, characterized in that the dispersion comprises 60% to 70% by weight of crosslinker and 30% to 40% by weight of plasticizer, the amounts indicated in % by weight being based on the total amount of the dispersion.

6. 3. Self-sealing tire sealant according to claim 1 or 2, characterized in that it is based on crosslinking of at least one polyolefin and / or rubber with said at least one crosslinking agent.

7. 3. Self-sealing tire sealant according to claim 1 or 2, characterized in that it comprises a) from 9% to 50% by weight of at least one rubber.

8. A self-sealing tire sealant as described in claim 1 or 2, characterized in that it contains a) 9% to 50% by weight of at least one butyl rubber (IIR).

9. A self-sealing tire sealant as described in claim 1 or 2, characterized in that it contains a) 9% to 50% by weight of at least one butyl rubber (IIR), the butyl rubber having an isoprene content of 0.5 to 5 mol%.

10. The self-sealing tire sealant of claim 9, wherein the butyl rubber has an isoprene content of 2.3 to 5 mol%.

11. 3. Self-sealing tire sealant according to claim 1 or 2, characterized in that it comprises b) 11% to 80% by weight of at least one polyolefin.

12. 3. A self-sealing tire sealant according to claim 1 or 2, characterized in that it comprises c) 2 to 15% by weight of at least one filler.

13. d) 0.5% to 7% by weight of said dispersion of at least one plasticizer and said at least one crosslinking agent.

3. The self-sealing tire sealant according to claim 1 or 2, comprising:

14. 3. Self-sealing tire sealant according to claim 1 or 2, characterized in that it comprises e) 0.5% to 8% by weight of at least one crosslinking initiator.

15. 3. The self-sealing tire sealant according to claim 1 or 2, characterized in that it comprises f) 1.5% to 10% by weight of at least one adhesive.

16. At least the following components: a1) 12% to 22% by weight of at least one rubber; b1) 58% to 78% by weight of at least one polyolefin; c1) 4% to 8% by weight of at least one filler; d1) 0.5% to 2.5% by weight of said dispersion of at least one plasticizer and said at least one crosslinker, wherein said dispersion is 50% to 80% by weight of crosslinker and 20% to 50% by weight of plasticizer; e1) 1.5% to 3.5% by weight of at least one crosslinking initiator; f1) 1.5 wt.% to 4.5 wt.% of at least one adhesive; 3. The self-sealing tire sealant according to claim 1 or 2, comprising:

17. At least the following components: a2) 13.5% to 29.5% by weight of at least one rubber; b2) 47% to 77% by weight of at least one polyolefin; c2) 2.5% to 7.5% by weight of at least one filler; d2) 1% to 4% by weight of said dispersion of at least one plasticizer and said at least one crosslinker, said dispersion comprising 50% to 80% by weight of crosslinker and 20% to 50% by weight of plasticizer; e2) 2% to 4% by weight of at least one crosslinking initiator; f2) 1.5 wt.% to 4.5 wt.% of at least one adhesive; 3. The self-sealing tire sealant according to claim 1 or 2, comprising:

18. At least the following components: a3) 15.5% to 35.5% by weight of at least one rubber; b3) 40% to 70% by weight of at least one polyolefin; c3) 2.5% to 7.5% by weight of at least one filler; d3) 2% to 5% by weight of said dispersion of at least one plasticizer and said at least one crosslinker, said dispersion comprising 50% to 80% by weight of crosslinker and 20% to 50% by weight of plasticizer; e3) 2.5% to 5.5% by weight of at least one crosslinking initiator; f3) 1.5 wt.% to 5.5 wt.% of at least one adhesive; 3. The self-sealing tire sealant according to claim 1 or 2, comprising:

19. At least the following components: a4) 26% to 50% by weight of at least one rubber; b4) 14.5% to 54.5% by weight of at least one polyolefin; c4) 3% to 9% by weight of at least one filler; d4) 3% to 7% by weight of said dispersion of at least one plasticizer and said at least one crosslinker, said dispersion comprising 50% to 80% by weight of crosslinker and 20% to 50% by weight of plasticizer; e4) 4% to 8% by weight of at least one crosslinking initiator; f4) 2 wt.% to 7 wt.% of at least one adhesive; 3. The self-sealing tire sealant according to claim 1 or 2, comprising:

20. A process for producing a self-sealing tire sealant according to claim 1, comprising at least the following process steps: X1) producing or providing a dispersion of at least one crosslinker in at least one plasticizer; X2) providing additional ingredients in one or more process steps; X3) adding the dispersion from step X1) to the ingredients of step X2); A process involving:

21. A pneumatic vehicle tire comprising the tire sealant of claim 1 or 2 on at least the inner surface opposite the threads.

22. The use of a dispersion of 50% to 80% by weight of at least one crosslinking agent in 20% to 50% by weight of at least one plasticizer in the manufacture of a self-sealing tire sealant, wherein the amounts indicated in % by weight are based on the total amount of the dispersion.

23. The use of claim 22, wherein the self-sealing tire sealant comprises 9% to 50% by weight of at least one butyl rubber (IIR), the butyl rubber having an isoprene content of 0.5 to 5 mol%.

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