Method for manufacturing vehicle pneumatic tires

Abstract

The invention relates to a method for manufacturing a vehicle pneumatic tire, comprising the process steps of: a) manufacturing or providing a vehicle pneumatic tire blank, comprising: i) a carcass blank comprising a plurality of reinforcing elements embedded in a first vulcanizable rubber compound, ii) a tread blank arranged radially above the carcass blank, and iii) an inner layer blank arranged radially below the carcass blank, comprising a second vulcanizable rubber compound comprising at least one butyl rubber and / or halobutyl rubber, b) applying a release agent to the surface of the inner layer blank in an application area to obtain a prepared vehicle pneumatic tire blank, c) vulcanizing the prepared vehicle pneumatic tire blank in a vulcanization mold to obtain a vehicle pneumatic tire with an inner tire layer.and d) materially bonded application of a functional layer to the inner tire layer, wherein the application takes place at least partially in the application area, wherein the combined mass fraction of polysiloxanes in the separation composition is 1% or less, based on the mass of the separation composition.

Description

[0001] The invention relates to a method for manufacturing a vehicle pneumatic tire. A vehicle pneumatic tire manufactured using the corresponding method is also disclosed, as is the use of a release agent to improve the removability of the vulcanized vehicle pneumatic tire from the vulcanization mold and to improve the bondability of a functional layer to the vulcanized vehicle pneumatic tire.

[0002] The tires of a vehicle have a significant influence on the driving safety-relevant properties of a vehicle, but also on its other rolling characteristics, for example with regard to noise development.

[0003] The occurrence of tire defects while driving has always been a major safety risk on the road. A complete puncture of a conventional pneumatic tire can lead to an unwanted loss of pressure, forcing the driver to change the tire, which in many cases must be done in the dangerous environment of the immediate vicinity of the road. To circumvent this problem, so-called self-sealing pneumatic tires were developed, which are now commercially available from various manufacturers.In these self-sealing pneumatic tires, an additional sealing layer, sometimes referred to as a "sealant," located inside the tire beneath the tread, ensures that any puncture in the tread area seals the resulting opening, preventing air from escaping and at least slowing down the associated pressure loss. General information on the technological background is disclosed, for example, in US 4287928 A, EP 3175975 B1, EP 3085523 B1, WO 2022237250 A1, and US 4263075 A.

[0004] Another class of functional layers that can be applied to the inside of the tire are noise-dampening layers, which help to dampen the noise generated during operation and thus reduce the environmental impact of emissions.

[0005] Corresponding functional layers, such as sealant layers or noise-dampening layers, are generally familiar to the expert from the state of the art.

[0006] In the current state of the art, the functional layers are regularly applied to the already vulcanized pneumatic tire. This application typically relies on a material-bonded connection. This can be achieved, for example, directly by applying the sealant layer and / or by using an adhesive.

[0007] For the expert, it is important that sufficient adhesion exists between the sealant composition and the interior of the vehicle tire, i.e., in particular the inner tire layer. To this end, prior art methods usually involve a separate pre-cleaning of the inner tire layer before the functional layer is applied, in order to maximize the adhesion of the resulting bond and to prevent, for example, contaminants from locally reducing the bond strength.

[0008] Pre-cleaning the inner tire liner requires additional work steps and places additional demands on the equipment used in the manufacturing process, as well as on the training of the workforce, especially when cleaning—as is often the case—is carried out using material-removing methods. Therefore, pre-cleaning the inner tire liner has a detrimental impact on the time and cost efficiency of manufacturing vehicle tires equipped with functional layers.

[0009] The primary objective of the present invention was to eliminate or at least reduce the disadvantages of the prior art.

[0010] In particular, the object of the present invention was to provide a method for manufacturing a vehicle pneumatic tire, with which vehicle pneumatic tires equipped with functional layers can be manufactured in a time- and cost-efficient manner.

[0011] The object of the present invention was to ensure that the vehicle pneumatic tires that could be produced using the specified method would exhibit excellent bond strength to the functional layers used.

[0012] A further objective of the present invention was to ensure that good adhesion could be achieved, in particular without pre-cleaning or at least with a reduced degree of pre-cleaning of the inner tire layer, and that the dependence on material-removing cleaning processes should be reduced.

[0013] It was a desirable requirement of the present invention that the solution to be specified should ideally manage as largely as possible without the use of potentially harmful substances that are harmful to health and / or the environment.

[0014] Furthermore, a secondary object of the present invention was to provide an advantageous vehicle tire equipped with a functional layer, which can be obtained using the described method. In addition, a secondary object of the present invention was to describe an advantageous use of a separating composition.

[0015] The inventors of the present invention have now discovered that a significant contribution to the adhesion, which is often perceived as insufficient without elaborate cleaning, during the application of functional layers results from the use of release agents. In the prior art, these release agents are used in almost all cases before the vulcanization of vehicle tires, particularly to achieve a lubricating effect and so-called "air-bleeding" at the interface between the inner tire layer and the vulcanizing bellows, or, after vulcanization, to enable damage-free removal from the vulcanizing mold, whereby silicone-containing release agents are used in the prior art.Based on this, the inventors of the present invention have found that the problems described above can be solved by using a release agent composition with a low polysiloxane content before vulcanizing vehicle tire blanks, as defined in the claims. In doing so, the inventors have succeeded in identifying a particularly advantageous alternative to polysiloxane-based release agent compositions, with which good adhesion can be achieved even without complex cleaning processes, while simultaneously achieving a release agent effect that is on par with that of polysiloxane-based release agent compositions.

[0016] The aforementioned problems are thus solved by the subject matter of the invention as defined in the claims. Preferred embodiments of the invention are described in the dependent claims and the following descriptions.

[0017] Such embodiments, which are hereinafter referred to as preferred, are combined in particularly preferred embodiments with features of other embodiments referred to as preferred. Combinations of two or more of the embodiments referred to below as particularly preferred are therefore especially preferred. Also preferred are embodiments in which a feature of one embodiment, referred to as preferred to any degree, is combined with one or more further features of other embodiments, which are referred to as preferred to any degree. Features of preferred vehicle pneumatic tires and uses result from the features of preferred methods.

[0018] Particularly preferred embodiments of the invention are disclosed in the exemplary embodiments. Particularly preferred embodiments of the invention have two or more, preferably four or more, of the preferred features of the invention disclosed below, which are also implemented in the exemplary embodiments.

[0019] Insofar as mass fractions are specified below, they are generally expressed in the industry as combined mass fractions of one or more components, thus indicating that the combined mass fraction of the respective components meets the relevant criteria. The unit phr (parts per hundred parts of rubber by weight) used here is the standard unit of measurement in the rubber industry for compound formulations. It specifies the mass fractions of the components in the rubber compound relative to the mass of the high-molecular-weight rubbers present in the compound (weight-average molar mass Mw according to GPC greater than 60,000 g / mol), where the combined mass fraction of the high-molecular-weight rubbers corresponds to 100 phr.

[0020] The invention relates to a method for manufacturing a vehicle pneumatic tire, comprising the following process steps: a) Manufacture or supply of a vehicle pneumatic tire blank, comprising: i) a carcass blank comprising a multitude of reinforcing elements embedded in a first vulcanizable rubber compound, ii) a tread blank arranged radially above the carcass blank, and iii) an inner layer blank arranged radially below the carcass blank, comprising a second vulcanizable rubber compound comprising at least a butyl rubber and / or halobutyl rubber, b) Applying a release agent to the surface of the inner layer blank in an application area to obtain a prepared vehicle pneumatic tire blank, c) Vulcanizing the prepared vehicle pneumatic tire blank in a vulcanization mold to obtain a vehicle pneumatic tire with an inner tire liner, and d) material-bonded application of a functional layer to the inner tire layer, wherein the application takes place at least partially in the application area, wherein the combined mass fraction of polysiloxanes in the separation composition is 1% or less, based on the mass of the separation composition.

[0021] The method according to the invention serves to manufacture a vehicle pneumatic tire, in particular a self-sealing and / or noise-dampening vehicle pneumatic tire.

[0022] The manufactured pneumatic vehicle tires can, in principle, be for a wide range of applications, including motorcycles.

[0023] However, the inventive method is particularly relevant for the production of pneumatic tires for cars or trucks. A preferred method is therefore one in which the pneumatic tire is a car or truck tire, preferably a car tire.

[0024] In the inventive method, a vehicle tire blank is first produced using a typical process. For this, a person skilled in the art can refer to methods known from the prior art. With regard to its structure, the vehicle tire blank to be produced initially corresponds to a typical vehicle tire blank. This means, in particular, that the unvulcanized vehicle tire blank comprises a carcass blank with reinforcing elements embedded in a vulcanizable rubber compound, above which the unvulcanized tread blank is arranged, while the inside of the vehicle tire blank is covered by the inner layer blank, from which the inner tire layer is to be obtained after vulcanization, which is primarily responsible for the airtightness of the manufactured vehicle tire.

[0025] For the first vulcanizable rubber compound, i.e., the vulcanizable rubber compound used for rubberizing the reinforcing elements, the person skilled in the art can, as well as for the vulcanizable rubber compound used in the tread blank, refer to all vulcanizable rubber compounds known from the prior art.

[0026] A preferred method with regard to the design of the carcass blank is one according to the invention, wherein the reinforcing elements are textile reinforcing elements or metallic reinforcing elements, preferably textile reinforcing elements.

[0027] To improve stability and load-bearing capacity, reinforcing layers, such as belt layers or coil bandages, can also be provided in the vehicle pneumatic tire in the usual manner. A method according to the invention is preferred in this case, wherein the vehicle pneumatic tire blank additionally comprises: iv) one or more reinforcement layer blanks arranged between the carcass blank and the tread blank.

[0028] The nature of the inner tire layer is important for the invention, which, according to the inventors, must comprise at least butyl rubber and / or halobutyl rubber, both of which are well known to those skilled in the art in tire manufacturing and are commercially available from various manufacturers.

[0029] In practice, the inner layer blank in the vehicle tire blank regularly lines the entire inward-facing surface to achieve the most complete sealing effect possible in the later vehicle tire. A preferred method according to the invention is therefore one in which the radially inner surface of the vehicle tire blank is substantially completely covered by the inner layer blank.

[0030] The inventors have succeeded in identifying particularly suitable materials for the composition of the second vulcanizable rubber compound used in the inner layer blank. These materials, in combination with the low-polysiloxane release agent compositions, achieve a good balance between the achievable adhesion of the functional layers and the ease of removal from the vulcanization mold. A preferred method according to the invention is one in which the second vulcanizable rubber compound comprises butyl rubber and / or halobutyl rubber in a combined mass fraction in the range of 70 to 100 phr, preferably in the range of 80 to 100 phr, and particularly preferably in the range of 90 to 100 phr. An additionally or alternatively preferred method according to the invention is one in which the second vulcanizable rubber compound comprises halobutyl rubber, preferably chlorobutyl rubber or bromobutyl rubber.A preferred method according to the invention is additionally or alternatively a method wherein the second vulcanizable rubber mixture comprises one or more fillers, preferably in a combined mass fraction of 30 phr or more, more preferably of 40 phr or more, particularly preferably of 60 phr or more, wherein the filler is preferably selected from the group consisting of carbon black and amorphous silicon dioxide, for example precipitated amorphous silicon dioxide, preferably carbon black.

[0031] According to the invention, a specific separating composition is applied to the vehicle pneumatic tire blank, more precisely to its inner tire layer, before vulcanization. This composition has a low content of polysiloxanes, in particular organopolysiloxanes, or preferably is even completely free of polysiloxanes.

[0032] According to the invention, this release agent is applied in a so-called application area. An exemplary method according to the invention is one in which the release agent is applied in a coating process, preferably by means of spray coating, which offers significant advantages, especially compared to manual application methods.

[0033] According to the invention, the release agent is applied to the surface of the inner layer blank in an application area. The application area thus defines the region in which the specific release agent composition has been applied. In the subsequent step, the functional layer is applied to the inner tire layer, partially within this application area. Those skilled in the art understand that it would theoretically be conceivable to prepare parts of the inner layer blank outside the application area without or with a different release agent composition. However, for essentially all embodiments, a method according to the invention is preferred in which the application area comprises 80% or more, preferably 90% or more, particularly preferably 95% or more, and most preferably essentially 100% of the surface of the inner layer blank.

[0034] The inventors have found that excellent results regarding the subsequent adhesion of the functional layers to be applied and the reduction of cleaning effort can be achieved if the polysiloxane content is reduced as much as possible. A preferred method according to the invention is one in which the combined mass fraction of polysiloxanes in the separation composition is 0.5% or less, preferably 0.2% or less, particularly preferably 0.1% or less, and most preferably 0.05% or less, based on the mass of the separation composition, wherein the separation composition is particularly preferably essentially free of polysiloxanes. The aforementioned limits are also particularly preferably achieved with regard to the solids content of the separation composition.

[0035] The inventors have succeeded in identifying advantageous alternatives for use as separation compositions. Advantageous low-polysiloxane and, in particular, polysiloxane-free separation compositions can be obtained based on polymeric polyol compounds, especially polyethylene glycol and polypropylene glycol. A preferred method according to the invention is one in which the separation composition comprises one or more polymeric polyol compounds, preferably in a combined mass fraction of 2% or more, particularly preferably 5% or more, and most preferably 10% or more, based on the mass of the separation composition. A particularly preferred method according to the invention is one in which the one or more polymeric polyol compounds are selected from the group consisting of polyglycols, preferably polyethylene glycol and polypropylene glycol.Particularly preferred, or alternatively, is a method according to the invention wherein one or more polymeric polyol compounds are selected from the group consisting of polymeric polyol compounds with a weight-average molar mass Mw (measured by GPC) of 1500 g / mol or more, preferably 3000 g / mol or more, and particularly preferably 4500 g / mol or more. The determination of the weight-average molar mass is carried out by gel permeation chromatography according to DIN 55672-1: 2016-03 (GPC with tetrahydrofuran as eluent, polystyrene standard; size exclusion chromatography; SEC).

[0036] Based on the inventors' experiments, it has been shown that excellent results can be achieved when fillers and / or surfactants are used in the separation composition, with silicates in particular achieving good results as separation agents.

[0037] In this context, a preferred method according to the invention is one in which the separation composition comprises one or more inorganic fillers, preferably in a combined mass fraction in the range of 2 to 45%, more preferably in the range of 5 to 40%, and particularly preferably in the range of 10 to 30%, based on the mass of the separation composition. A preferred method according to the invention is one in which the one or more inorganic fillers are selected from the group consisting of silicon-containing inorganic fillers, preferably silicates.

[0038] A preferred method according to the invention is additionally or alternatively a method wherein the separation composition comprises one or more surfactant compounds, preferably in a combined mass fraction in the range of 0.05% to 2%, more preferably in the range of 0.1% to 1.5%, and particularly preferably in the range of 0.2% to 1.0%, based on the mass of the separation composition.

[0039] In particularly preferred embodiments, the separation composition combines polymeric polyol compounds with fillers and / or surfactant compounds, preferably with fillers and surfactant compounds, preferably in the respective specified mass ranges. The combination of polyglycols with silicates and surfactant compounds is particularly preferred.

[0040] According to the inventors, a process in which the separation composition is used as a dispersion, particularly an aqueous dispersion, is preferred in the vast majority of cases, and the inventors have succeeded in identifying suitable solids contents for aqueous dispersion. Therefore, a process according to the invention is initially preferred, wherein the separation composition is a dispersion, preferably an aqueous dispersion.

[0041] According to the inventors, it is advantageous for the aqueous dispersion to consist as largely as possible of water with respect to its liquid phase. A preferred method according to the invention is therefore one in which the liquid phase of the aqueous dispersion consists of 70% or more, preferably 80% or more, particularly preferably 90% or more, and most preferably 95% or more, of water, based on the mass of the liquid phase.

[0042] Furthermore, the inventors have also identified suitable ranges for the solids content of the dispersion. A preferred method, either additionally or alternatively, is one in which the dispersion has a solids content in the range of 30 to 60%, preferably in the range of 40 to 50%.

[0043] A preferred method according to the invention is wherein the separation composition has an basis weight in the range of 2 to 30 g / m². 2 , preferably in the range of 5 to 25 g / m³ 2 , particularly preferably in the range of 10 to 20 g / m³ 2 , is applied. These values ​​are related to the order and therefore, in the case of dispersions, also include, for example, the solvent medium ("wet weight").

[0044] The appropriately prepared vehicle tire blank is vulcanized in process step c), whereby the inner layer of the tire is formed from the inner layer blank. This inner layer is at least partially covered with the release agent composition or a separating layer formed therefrom during vulcanization, as a result of the preceding coating with the release agent composition. In their own experiments, the inventors have identified suitable vulcanization temperatures with which excellent results could be achieved in the process according to the invention, particularly with regard to the surface quality of the inner tire layer. A preferred method according to the invention involves vulcanization at a temperature in the range of 130 to 200 °C, preferably in the range of 150 to 180 °C.

[0045] After vulcanization, the functional layer is applied, whereby this application is carried out at least partially, preferably predominantly, and particularly preferably substantially completely, by means of a material bond, for example, using an adhesive or by utilizing the inherent tackiness of a sealant composition. According to the invention, the application takes place at least partially in the application area, so that the functional layer is applied at least partially where the release agent composition identified as advantageous was actually used. Those skilled in the art understand that, to maximize the advantages of the method according to the invention, it is expedient to apply the functional layer as extensively as possible in the area that was prepared with the specific release agent composition.In this context, a method according to the invention is preferred, wherein the application takes place to 50% or more, preferably 70% or more, particularly preferably 90% or more, and most preferably essentially 100% in the application area, with reference to the contact area between the functional layer and the vehicle tire.

[0046] A major advantage of the present invention is that cleaning the vulcanized inner tire layer can potentially be dispensed with, while still achieving excellent bond strength in the connection of the functional layer. This significantly improves the time and cost efficiency of tire manufacturing. Furthermore, the use of complex cleaning devices, such as lasers, can be avoided. At the same time, those skilled in the art understand that, despite these advantages, it is still possible to clean the surface of the inner tire layer. In this case, the invention offers the advantage of reducing the required cleaning effort and its extent. For example, instead of material removal, such as with brushes or lasers, a simple wipe is sufficient to remove surface dust.However, it is particularly preferred if no cleaning step is required at all.

[0047] A method according to the invention is therefore conceivable, wherein the method before process step d) additionally comprises the following process step: e) Cleaning the inner tire layer in the area intended for the application of the functional layer.

[0048] However, a method according to the invention is preferred in which the application of a functional layer takes place directly on the inner tire layer obtained after vulcanization.

[0049] A method according to the invention is also preferred, or alternatively, wherein the inner tire layer in the area provided for the application of the functional layer is not cleaned with a material-removing cleaning method.

[0050] The method according to the invention is suitable in principle for all applications in which a component is to be bonded to the inner layer of a vehicle tire. This could include, for example, layers of a sealant composition (for so-called "self-sealing tires"; SST), noise-reducing layers (for so-called "noise-canceling tires"; NCT), or additional reinforcing layers.

[0051] To represent this wide range of possibilities, the corresponding components are referred to as functional layers within the scope of the present invention. A preferred method according to the invention is one in which the functional layer is selected from the group consisting of sealing layer layers and noise-dampening layer layers.

[0052] In the case of SST, a method according to the invention is preferred, wherein the sealant layers are produced by applying a sealant composition to the inner tire layer. Suitable sealant compositions are known to those skilled in the art from the prior art.

[0053] A preferred method for the NCT is one in which the noise-dampening layer is attached to the inner tire liner using an adhesive. Suitable noise-dampening layers, which may, for example, take the form of rubber layers or foams, are known to those skilled in the art.

[0054] In connection with the invention, a vehicle pneumatic tire, manufactured or manufacturable using the method according to the invention, is also disclosed.

[0055] Furthermore, the use of a separating composition as disclosed above as a separating agent in the vulcanization of a vehicle pneumatic tire in a vulcanization mold is disclosed to improve the removability of the vulcanized vehicle pneumatic tire from the vulcanization mold and to improve the bondability of a functional layer to the vulcanized vehicle pneumatic tire, wherein the combined mass fraction of polysiloxanes in the separating composition is 1% or less, based on the mass of the separating composition.

[0056] The invention and preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying figure. The figure shows: Fig. 1 A schematic representation of the method according to the invention in a preferred embodiment.

[0057] Fig. Figure 1 shows a schematic representation of the process steps of the method according to the invention in a flowchart. In a first step a), which is marked with 100, a vehicle pneumatic tire blank is first produced, which, in addition to the carcass blank, the inner layer blank arranged on the inside thereof and the tread blank arranged above it, may also include other components, for example blanks for sidewall components or belt layers.

[0058] In the example shown, a release agent is applied to the inner layer blank in step b) marked 102 in a mass application of approximately 15 g / m² before vulcanization. 2 applied (“wet weight”). The separation composition in the discussed example is the Fig. 1. An aqueous dispersion with a solids content of approximately 50%, comprising a polymeric glycol, e.g., polyethylene glycol or polypropylene glycol, silicates as fillers, and surfactant compounds. The separation composition is essentially free of polysiloxanes.

[0059] After this preparation, the vehicle pneumatic tire blank is processed in step c) marked 104. Fig. 1. The inner layer is vulcanized in a vulcanization mold and given a tread pattern there. During this process, a separating layer forms on the previously prepared surface of the inner layer blank, which is transformed into a tire inner layer through vulcanization, as a reaction product of the separating compound, whereby in particular the water at least partially evaporates.

[0060] After the vulcanized vehicle tire is removed from the vulcanization mold, a sealant composition is applied as a functional layer to the surface of the inner tire layer below the tread in the step marked 106 by applying a formless mass, without any cleaning of the corresponding surface having taken place in the meantime, in particular no material-removing cleaning.

[0061] This results in a time- and cost-efficient way to obtain a pneumatic tire which, in use, exhibits excellent bond strength between the sealant composition and the inner tire layer.

[0062] By using polymeric glycols, especially in combination with silicate-based fillers and surfactant compounds, an advantageous release agent composition is obtained in this example, which is easy to apply as an aqueous dispersion and with which not only good adhesion can be achieved without elaborate cleaning, but also a release agent effect is achieved that is on the same level as that of polysiloxane-based release agent compositions known from the prior art. Reference symbol list 100 Procedure step a) 102 Procedure step b) 104 Procedure step c) 106 Procedure step d) QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 4287928 A

[0003] EP 3175975 B1

[0003] EP 3085523 B1

[0003] WO 2022237250 A1

[0003] US 4263075 A

[0003]

Claims

A method for manufacturing a vehicle pneumatic tire, comprising the process steps of: a) manufacturing or providing a vehicle pneumatic tire blank, comprising: i) a carcass blank comprising a plurality of reinforcing elements embedded in a first vulcanizable rubber compound, ii) a tread blank arranged radially above the carcass blank, and iii) an inner liner blank arranged radially below the carcass blank, comprising a second vulcanizable rubber compound comprising at least a butyl rubber and / or halobutyl rubber, b) applying a release agent to the surface of the inner liner blank in an application area to obtain a prepared vehicle pneumatic tire blank, c) vulcanizing the prepared vehicle pneumatic tire blank in a vulcanization mold to obtain a vehicle pneumatic tire with an inner liner.andd) materially bonded attachment of a functional layer to the inner tire layer, wherein the attachment takes place at least partially in the application area, wherein the combined mass fraction of polysiloxanes in the separating composition is 1% or less, based on the mass of the separating composition. The method according to claim 1, wherein the combined mass fraction of polysiloxanes in the separation composition is 0.5% or less, preferably 0.2% or less, particularly preferably 0.1% or less, most preferably 0.05% or less, based on the mass of the separation composition, wherein the separation composition is particularly preferably substantially free of polysiloxanes. Method according to one of claims 1 or 2, wherein the separation composition comprises one or more polymeric polyol compounds, preferably in a combined mass fraction of 2% or more, particularly preferably of 5% or more, most preferably of 10% or more, based on the mass of the separation composition. Method according to claim 3, wherein one or more polymeric polyol compounds are selected from the group consisting of polyglycols, preferably polyethylene glycol and polypropylene glycol. A method according to any one of claims 1 to 4, wherein the separation composition comprises one or more inorganic fillers, preferably in a combined mass fraction in the range of 2 to 45%, more preferably in the range of 5 to 40%, more preferably in the range of 10 to 30%, based on the mass of the separation composition, and / or wherein the separation composition comprises one or more surfactant compounds, preferably in a combined mass fraction in the range of 0.05% to 2%, more preferably in the range of 0.1 to 1.5%, more preferably in the range of 0.2 to 1.0%, based on the mass of the separation composition. Method according to claim 5, wherein one or more inorganic fillers are selected from the group consisting of silicon-containing inorganic fillers, preferably silicates. Method according to any one of claims 1 to 6, wherein the separation composition is a dispersion, preferably an aqueous dispersion, wherein the dispersion preferably has a solids content in the range of 30 to 60%, particularly preferably in the range of 40 to 50%. Method according to any one of claims 1 to 7, wherein the separation composition is applied with an areal weight in the range of 2 to 30 g / m2, preferably in the range of 5 to 25 g / m2, particularly preferably in the range of 10 to 20 g / m2. Method according to any one of claims 1 to 8, wherein the application of a functional layer takes place directly on the inner tire layer obtained after vulcanization, and / or wherein the inner tire layer in the area provided for the application of the functional layer is not cleaned by a material-removing cleaning process. Method according to any one of claims 1 to 9, wherein the functional layer is selected from the group consisting of sealing layer layers and noise-dampening layer layers.

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