Method for producing a low-noise pneumatic vehicle tyre, and low-noise pneumatic vehicle tyre

Abstract

The invention relates to a method for producing a pneumatic vehicle tyre (10), comprising: i) a tread (12) lying on the outside in the radial direction, ii) a tyre inner layer (14) lying further on the inside in the radial direction relative to the tread (12), and iii) a porous noise-damping layer (16) lying further on the inside in the radial direction relative to the tyre inner layer (14), comprising the step of: a) producing the porous noise-damping layer (16) by integrally bonding a plurality of rubber particles (18) by means of an adhesive, wherein the rubber particles (18) consist at least partially of a rubber material.

Description

[0001] 202401054

[0002] 1

[0003] Method for manufacturing a low-noise vehicle pneumatic tire and low-noise vehicle pneumatic tires

[0004] Description

[0005] The invention relates to a method for manufacturing a vehicle pneumatic tire and a vehicle pneumatic tire manufactured therein. A porous noise-dampening layer and the use of such a porous noise-dampening layer in the manufacture of low-noise vehicle pneumatic tires are also disclosed.

[0006] Modern pneumatic tires are high-performance products whose numerous properties are tailored to specific application requirements. They are subject to strict regulatory requirements and high customer expectations in many respects. In addition to rolling characteristics and durability, these expectations also include noise levels when driving with these tires, as tires make a significant contribution to a vehicle's overall noise.

[0007] To optimize noise characteristics, i.e., to achieve low-noise vehicle tires, prior art solutions have been developed that rely on the use of so-called noise-dampening layers. These noise-dampening layers are additional layers, which can be used, for example, in the form of foams or rubber layers, and which are usually placed radially beneath the tread on the inner layer of pneumatic tires. The use of these additional layers can advantageously reduce noise generation. Despite the advantageous effects 202401054

[0008] 2. Regarding noise characteristics, the use of corresponding noise-reducing layers in practice is also associated with numerous challenges. For example, the additional layers usually increase the weight of the vehicle tires, which can negatively affect fuel consumption, so a good compromise between the tire's properties must regularly be found.

[0009] A disadvantage of using noise-reducing layers becomes particularly apparent in the manufacturing processes for corresponding low-noise pneumatic tires. Applying these layers requires additional work steps, especially for cleaning the areas intended for application and the use of additional materials, such as adhesives. This negatively impacts the time and cost efficiency of the manufacturing process and, in particular, increases the equipment required for producing such pneumatic tires.

[0010] In current technology, noise-reducing layers are typically attached to the inner ply of the already vulcanized tire as continuous layers of material, for example, foam layers, using a suitable adhesive, such as a rubber-based adhesive. To prevent the noise-reducing layer from detaching unintentionally, it is essential to achieve sufficient adhesion between the noise-reducing layer and the tire's inner ply, ensuring a secure fit of the noise-reducing layer within the tire, especially at high speeds.

[0011] Against the backdrop of an increasing awareness of the need for more sustainable economic practices and a more careful use of fossil resources, setting a maximum adhesion between the noise reduction layer and the 202401054

[0012] 3

[0013] However, vehicle tires also have disadvantages in some respects. While the strong adhesion and the resulting bond strength are desirable in the use of vehicle tires, they hinder time- and cost-efficient recycling of the tires at the end of their lifespan. Recycling such used tires regularly reveals that the reliable removal of the noise-dampening layer, which often cannot be recycled together with the rest of the tire due to material incompatibilities, is very difficult and regularly requires a significant investment of time and labor.

[0014] The primary objective of the present invention was to eliminate or at least reduce the disadvantages of the prior art.

[0015] In particular, the object of the present invention was to provide a method for manufacturing a vehicle pneumatic tire which enables the production of low-noise vehicle pneumatic tires and can be carried out in a particularly time- and cost-efficient manner.

[0016] Therefore, an object of the present invention was that the specified method should minimize the processing effort required for applying noise-absorbing layers, and should ideally provide a method that is simple in terms of equipment and can be easily automated. It was also desirable that the specified method should reduce the need for materials required for applying the noise-absorbing layer, with a particular aim of reducing the need for fossil raw materials.

[0017] An important objective of the present invention was to enable the production of low-noise pneumatic vehicle tires using the specified method, which would later prove to be durable and resistant to wear in use. 202401054

[0018] 4

[0019] The process must provide a connection between the vehicle tire and the noise-dampening layer that ensures a reliable fit of the noise-dampening layer, especially at high speeds, while simultaneously allowing for simple and efficient recycling of the vehicle tires at the end of their service life. Therefore, one objective of the described process was to ensure that the resulting vehicle tires could resolve the conflicting objectives between high durability of the noise-dampening layer's attachment and effective noise reduction on the one hand, and advantageous recyclability on the other.

[0020] Furthermore, it was an object of the present invention to provide a corresponding low-noise vehicle pneumatic tire with excellent recyclability, which can be obtained using the specified method.

[0021] The inventors of the present invention have now found that the problems described above can be solved if, instead of classic noise-dampening layers known from the prior art, a noise-dampening layer is used which is made from a plurality of rubber particles which are bonded together by means of an adhesive, as defined in the claims, wherein, in particular, rubber particles obtained from recycled tires can also be used for the rubber particles.

[0022] Surprisingly, this method allows for the relatively simple production of advantageous pneumatic tires that possess excellent noise-dampening properties and are simultaneously highly recyclable, as high material compatibility with the other components of the recycled tires is ensured, as shown in 202401054.

[0023] 5. It is possible in an advantageous way to reduce the need for fossil raw materials by using rubber particles obtained from old tires.

[0024] 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.

[0025] 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 referred to as preferred to any degree. Features of preferred vehicle pneumatic tires, porous noise-dampening layers, and uses result from the features of preferred methods.

[0026] Particularly preferred embodiments of the invention are disclosed in the exemplary embodiments. Particularly preferred embodiments of the invention have two or more, preferably three or more, and most preferably four or more, of the preferred features of the invention disclosed below, which are also implemented in the exemplary embodiments.

[0027] The invention relates in particular to a method for manufacturing a vehicle pneumatic tire, comprising: i) a radially outer tread, 202401054

[0028] 6 ii) a tire inner layer located further inwards in the radial direction relative to the tread, and iii) a porous noise-dampening layer located further inwards in the radial direction relative to the tire inner layer, comprising the step of: a) producing the porous noise-dampening layer by bonding a plurality of rubber particles by means of an adhesive, wherein the rubber particles consist at least partially of a rubber material.

[0029] The method according to the invention serves to manufacture a vehicle pneumatic tire which can be operated as quietly as possible in subsequent use. Thus, it is a method according to the invention, wherein the vehicle pneumatic tire is a noise-dampened vehicle pneumatic tire.

[0030] An advantage of the method according to the invention is that it can, in principle, be applied to all types of vehicle tires. An example of the method according to the invention is a motorcycle tire, a passenger car tire, or a truck tire, preferably a passenger car tire.

[0031] The process generally involves the use of vehicle pneumatic tires, for example by manufacturing or providing suitable vehicle pneumatic tires, which are to be provided with a noise-dampening layer in the inventive method.

[0032] Vehicle pneumatic tires are generally well known to those skilled in the art and are commercially available from numerous different manufacturers. The method according to the invention can, in principle, be applied to all types of vehicle pneumatic tires. For the purposes of the present invention, it is advantageous to focus only on the parts of 202401054

[0033] 7

[0034] Reference is made to vehicle pneumatic tires, which are helpful for understanding and defining the present invention. Accordingly, it is defined above that the vehicle pneumatic tire comprises a radially outer tread and a radially inner tire layer, which, in the inventors' opinion, should be the case for essentially all vehicle pneumatic tires. For most cases, a method according to the invention is therefore relevant, wherein the tread has a profile on the radially outer surface. A method according to the invention is preferred for most cases, wherein the tire layer substantially completely covers the radially inner surface of the vehicle pneumatic tire.

[0035] Between the tread and the inner tire layer, the various other components of typical pneumatic tires can be present in the usual way, for example, the tire carcass or reinforcing layers, such as belt plies. For most cases, a method according to the invention is therefore particularly relevant, wherein the pneumatic tire additionally comprises one or more, preferably two or more, and especially preferably three or more, further components arranged at least partially between the tread and the inner tire layer. An exemplary method according to the invention is one in which the pneumatic tire additionally comprises: iv) a tire carcass arranged radially outwards to the inner tire layer.

[0036] An exemplary additional or alternative method according to the invention is also a method wherein the vehicle pneumatic tire further comprises: v) one or more, preferably two or more, reinforcement layers arranged at least partially between the tread and the inner tire layer, wherein the reinforcement layers are preferably selected from the group consisting of belt layers and coil bandages, 202401054

[0037] 8 wherein the reinforcement layers preferably comprise one or more rubberized reinforcing elements.

[0038] The pneumatic tire produced according to the invention comprises, as an essential component, a noise-dampening layer which is located further inward in the radial direction relative to the inner tire layer. This noise-dampening layer is preferably arranged below the tread in the radial direction, since this positioning results in particularly advantageous noise-dampening properties. A preferred method according to the invention is one in which the porous noise-dampening layer and the tread are arranged in the radial direction at least partially, preferably predominantly, and most preferably substantially completely, aligned.

[0039] A key aspect of the present invention is that the porous noise-dampening layer is not formed by a conventional foam, for example a polyurethane foam, as is frequently used in the prior art, but that the porous noise-dampening layer is produced by the material-bonded connection of a plurality of rubber particles by means of an adhesive, wherein the rubber particles consist as far as possible of a rubber material.

[0040] The inventors have recognized that the production of the corresponding porous noise-dampening layer according to the invention can advantageously be carried out either separately from the vehicle tire in a preliminary step or directly by creating the porous noise-dampening layer inside the vehicle tire, thereby advantageously adapting the inventive method to different conditions of various manufacturing processes. In this respect, however, the inventors consider it particularly preferred to produce the porous noise-dampening layer in the inventive method 202401054

[0041] 9. to be produced directly inside the vehicle tire. A preferred method according to the invention is therefore, wherein the production of the porous noise-dampening layer by material-bonding the plurality of rubber particles takes place at least partially before the porous noise-dampening layer is applied to the vehicle tire, and / or wherein the porous noise-dampening layer is produced as a web-shaped or ring-shaped layer material before the porous noise-dampening layer is applied to the vehicle tire. A particularly preferred method according to the invention is additionally or alternatively one which further comprises the following step: b) Applying the produced porous noise-dampening layer to the vehicle tire.

[0042] However, a method according to the invention is preferred in which the production of the porous noise-dampening layer takes place on the inside of the vehicle tire, preferably directly on the inner tire layer.

[0043] According to the invention, the porous noise-dampening layer is produced by the metallurgical bonding of rubber particles. In accordance with the skilled person's understanding, these rubber particles each comprise a rubber material, which corresponds to the material from which vehicle tires are largely made. This results in advantageous recyclability of the vehicle tires produced in this way, since separation of the noise-dampening layer prior to recycling can be largely dispensed with. The fact that the rubber particles consist at least partially of a rubber material thus significantly improves the recyclability of the corresponding vehicle tires.

[0044] The inventors suggest that the advantages are more pronounced the more the rubber particles are formed from the rubber material, with particularly advantageous recyclability being especially evident in 202401054

[0045] 10 then results when the rubber particles consist essentially entirely of the rubber material. A preferred method according to the invention is one in which the rubber particles consist of a mass fraction of 70% or more, preferably 90% or more, particularly preferably 99% or more, and most preferably essentially 100%, of the rubber material.

[0046] The inventors have succeeded in identifying particularly preferred embodiments for the formation of the rubber particles. During the development of the present invention, it has become apparent that it is advantageous to use rubber particles obtained from the recycling of old rubber products, especially used tires. The quality of such recycled rubber particles is advantageously perfectly adequate for the intended purpose of noise damping.

[0047] Particularly when recycling used tires, a synergistic advantage arises from the fact that the noise-dampening layer consists of a tire-specific rubber material, which further simplifies the recycling of the corresponding vehicle tire. As a further synergistic effect, the inventive method for manufacturing new, noise-dampened vehicle tires uses precisely those materials whose use in turn reduces the need for fossil raw materials, thus achieving a particularly advantageous process from an ecological perspective.A preferred method according to the invention is therefore one in which the rubber particles consist at least partially, preferably to a mass fraction of 50% or more, particularly preferably of 70% or more, very preferably of 90% or more, particularly preferably of substantially 100%, of a recycled rubber material, preferably a recycled rubber material from the recycling of used tires, and / or 202401054.

[0048] 11 wherein the rubber particles are produced or producible at least partially, preferably to a mass fraction of 50% or more, particularly preferably to a mass fraction of 70% or more, very preferably to a mass fraction of 90% or more, particularly preferably to a mass fraction of substantially 100%, by comminution of a recycled rubber product, preferably a used tire, and / or wherein the rubber particles are obtained at least partially, preferably to a mass fraction of 50% or more, particularly preferably to a mass fraction of 70% or more, very preferably to a mass fraction of 90% or more, particularly preferably to a mass fraction of substantially 100%, in the course of a retreading process of used tires.

[0049] The inventors propose that, in a preferred embodiment, the production of the required rubber particles can be directly integrated into the inventive method. A preferred inventive method therefore comprises the following additional step: a) Producing a plurality of rubber particles by shredding a recycled rubber product, preferably a used tire, and particularly preferably the tread of a used tire, wherein the production preferably takes place during the removal of the tread of a used tire as part of a retreading process.

[0050] In order to form a porous noise-dampening layer from the multitude of rubber particles, it is necessary to connect the rubber particles together, which in the inventive method is achieved by means of a material-bonded connection created by an adhesive.

[0051] It can be seen as an advantage of the method according to the invention that, in principle, adhesives used in the prior art for fixing tire components to vehicle tires can be used to bond the rubber particles to the noise-dampening layer. In this respect, 202401054

[0052] 12. The person skilled in the art, for example, can use the adhesive material with which they would have fixed the conventional noise-dampening layers to the vehicle tire in conventional methods. Advantageously, this makes it possible that the material logistics of the materials required for production do not need to be adapted to the method according to the invention, or only to a minor extent.

[0053] From a manufacturing perspective, the inventors propose that reactive adhesives, in particular, can be used, the curing of which can be induced, for example, by radiation curing, moisture curing, or thermal curing. The corresponding design particularly favors a layer-based structure of the noise-dampening layer, as further disclosed below, since the noise-dampening layer can be efficiently built up layer by layer. A preferred method according to the invention is thus one in which the adhesive is a reactive adhesive, and the adhesive is particularly preferably selected from the group consisting of radiation-curing adhesives, moisture-curing adhesives, and thermally curing adhesives.

[0054] In developing the invention, the inventors identified various ways to produce the porous noise-dampening layers used according to the invention in a time- and cost-efficient manner. The inventors consider the layered construction of the noise-dampening layer to be particularly preferred, in which a layer of rubber particles is applied to an underlying layer of rubber particles. To create the material-bonded connection, it is generally conceivable to pre-coat the rubber particles with the adhesive and / or to apply a layer of adhesive after each layer of rubber particles, onto which the next layer of rubber particles can be applied. This 202401054

[0055] 13

[0056] According to the inventors, both methods prove to be advantageous, with the choice depending on which embodiment the person skilled in the art can better implement using the available equipment. A method according to the invention is generally preferred, wherein the production of the porous noise-dampening layer comprises the layer-by-layer application of layers to rubber particles until the desired final thickness of the porous noise-dampening layer is reached. A method according to the invention is particularly preferred, wherein the production of the porous noise-dampening layer comprises coating the rubber particles with the adhesive before the porous noise-dampening layer is formed. A method according to the invention is particularly preferred, either additionally or alternatively, wherein the production of the porous noise-dampening layer comprises the layer-by-layer application of layers to rubber particles pre-coated with adhesive.A preferred method according to the invention is additionally or alternatively a method wherein the production of the porous noise-dampening layer comprises the layer-by-layer application of layers of rubber particles, wherein the adhesive is applied to the applied layers after each application.

[0057] In principle, the rubber particles can be applied using a variety of devices, particularly in layers. The methods used can range from very simple, manual methods in which the rubber particles are sprinkled onto the underlying layers. However, the inventors believe that spraying devices are particularly suitable for the large-scale industrial production of such vehicle tires. These devices allow the rubber particles, which may be pre-coated with adhesive, to be applied very easily and very uniformly. Such spraying devices are especially well-suited for forming the porous noise-dampening layer directly within the vehicle tire. 202401054

[0058] 14

[0059] A preferred method according to the invention is one in which the production of the porous noise-dampening layer comprises spraying the rubber particles with a spraying device, wherein the spraying device is preferably moved relative to the porous noise-dampening layer to be produced during production, particularly preferably by moving the spraying device and / or rotating the vehicle tire.

[0060] In addition to preferred variants for the manufacture of the porous noise-dampening layer to be applied according to the invention, the inventors have also succeeded in identifying preferred designs for its dimensioning.

[0061] Firstly, in accordance with the procedure known from the prior art, it is preferred, particularly with regard to the noise reduction effect to be achieved, but also with regard to uniform rolling behavior, to extend the noise reduction layer as far as possible over the entire circumference of the vehicle tire. A preferred method according to the invention is therefore one in which the porous noise reduction layer extends over at least 90% of the circumference, preferably over at least 95% of the circumference, and most preferably substantially over the entire circumference, of the vehicle tire.

[0062] Based on this, the inventors recognized that, from a manufacturing perspective, the inventive method makes it particularly advantageous to produce segmented noise-damping layers, since this can be controlled directly in the vehicle tire, for example, simply by controlling a spray nozzle. In addition to the somewhat less preferred circumferential segmentations, this makes it particularly possible to produce two or more noise-damping partial layers spaced apart along the axial direction, which advantageously allows the application characteristics of the vehicle tire to be further improved.

[0063] 15. To be adapted more specifically to the respective application. Preferably, or alternatively, a method according to the invention is used, wherein the porous noise-damping layer is designed as a multi-part noise-damping layer, comprising two or more, preferably three or more, particularly preferably four or more, noise-damping partial layers distributed over the circumference and / or the axial direction.

[0064] Regarding the dimensions of the noise-dampening layer, the inventors propose that, to resolve the existing conflicts of objectives between material requirements, overall weight, and achievable noise reduction, it should be neither too thin nor too thick. The inventors consider it advantageous to align the width of the noise-dampening layer, possibly in combination with several noise-dampening sub-layers, as closely as possible with the width of the tire contact patch. A preferred method according to the invention involves the porous

[0065] The noise-dampening layer has a thickness in the radial direction of 5 to 75 mm, preferably in the range of 10 to 60 mm, and particularly preferably in the range of 15 to 45 mm. A preferred or alternative method according to the invention is further preferred, wherein the quotient formed by the width of the tire contact patch divided by the width of the porous noise-dampening layer, in each case transverse to the circumferential direction of the vehicle tire, is in the range of 0.5 to 1.6, preferably in the range of 0.7 to 1.4, particularly preferably in the range of 0.9 to 1.2, and most preferably in the range of 0.95 to 1.05.

[0066] A method according to the invention is generally preferred, wherein the porous noise-damping layer has an average density in the range of 0.3 to 0.9 g / cm³. 3 , preferably in the range of 0.4 to 0.8 g / cm³ 3 , particularly preferably in the range of 0.5 to 0.7 g / cm³ 3, exhibits, and / or wherein the porous noise-damping layer has an average basis weight in the range of 0.1 to 7.0 g / cm² 2 , preferably in the range of 0.5 to 5.0 g / cm³ 2 , particularly preferably in the range of 1.0 to 3.0 g / cm³ 2 , exhibits. 202401054

[0067] 16

[0068] The advantageous flexibility of the method according to the invention allows the porous noise-dampening layer to be produced on virtually any substrate. However, for the vast majority of cases, the inventors consider a configuration in which the noise-dampening layer is arranged on the inner tire liner to be preferable. Therefore, a method according to the invention is preferred in which the porous noise-dampening layer is connected to the inner tire liner at least partially, preferably predominantly, and particularly preferably essentially over the entire surface, preferably by a material bond.

[0069] At least theoretically, it would be conceivable to combine the rubber particles bonded together by the adhesive in the noise-dampening layer with other materials. This could be particularly advantageous for high-performance applications that require specific adaptation of the noise-dampening layer's properties. However, those skilled in the art understand that the use of additional materials in the porous noise-dampening layer inherently carries the risk of impairing the advantageous recyclability of the resulting pneumatic tires. Accordingly, for essentially all embodiments, it is preferable for the porous noise-dampening layer to be formed as largely as possible from the rubber particles and the adhesive.A preferred method according to the invention is therefore one in which the porous noise-dampening layer consists of the rubber particles and the adhesive to a mass fraction of 80% or more, preferably 90% or more, particularly preferably 95% or more, most preferably 99% or more, and particularly preferably substantially 100%, based on the mass of the porous noise-dampening layer. A preferred method according to the invention is additionally or alternatively one in which the combined mass fraction of the rubber particles in the porous noise-dampening layer is 50% or more, preferably 60% or more, and particularly preferably 70% or more.

[0070] 17 particularly preferably 80% or more, particularly preferably 90% or more.

[0071] The noise-dampening layer to be used according to the invention is porous, as defined above, meaning that it has cavities in its interior. Advantageously, its manufacture from individual rubber particles allows those skilled in the art to easily create the required porosity, since the corresponding gaps arise automatically because the particles do not fit together perfectly. The inventors of the present invention have thus succeeded in identifying particularly suitable degrees of porosity with which especially good noise-dampening properties can be achieved, with open-pore porosity being considered particularly advantageous for the noise-dampening effect.A preferred method according to the invention is one in which the porous noise-dampening layer has an average porosity of 30% or more, preferably 35% or more, and particularly preferably 40% or more, and / or in which the porous noise-dampening layer has an average porosity in the range of 10 to 60%, preferably in the range of 15 to 50%, and particularly preferably in the range of 20 to 40%. The corresponding porosity, i.e., the ratio of void volume to total volume, can be determined in the usual manner in a cross-section through the porous noise-dampening layer as the part not covered by material, for example, using image analysis software.

[0072] A method according to the invention is generally preferred, wherein the porous noise damping layer is an open-pored noise damping layer.

[0073] The invention also relates to a vehicle pneumatic tire, preferably manufactured or manufacturable using the inventive method, comprising: i) a radially outward-facing tread strip, 202401054

[0074] 18 ii) a tire inner layer located further inwards in the radial direction relative to the tread, and iii) a porous noise-dampening layer located further inwards in the radial direction relative to the tire inner layer, wherein the porous noise-dampening layer comprises a plurality of rubber particles which are joined together by a material bond using an adhesive, wherein the rubber particles consist at least partially of a rubber material.

[0075] Also disclosed is a porous noise-dampening layer, in particular for use in a method according to the invention, wherein the porous noise-dampening layer comprises a plurality of rubber particles which are connected to each other by a material-bonded connection using an adhesive, wherein the rubber particles consist at least partially of a rubber material.

[0076] Also disclosed is the use of a porous noise-damping layer as disclosed above in the manufacture of low-noise pneumatic vehicle tires with a noise-damping layer located radially inside the inner layer of the tire to improve the recyclability of the low-noise pneumatic vehicle tires.

[0077] The invention and preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying figures. These figures show:

[0078] Fig. 1 shows a schematic cross-sectional view through a vehicle pneumatic tire according to the invention in a preferred embodiment; and

[0079] Fig. 2 is a schematic visualization of process step a) of the method according to the invention in a preferred embodiment. 202401054

[0080] 19

[0081] Fig. 1 shows a highly simplified, schematic cross-sectional view through a vehicle pneumatic tire 10 according to the invention in a preferred embodiment, as it can be manufactured in the method according to the invention.

[0082] The vehicle pneumatic tire 10 comprises a radially outer profiled tread 12 and a radially inner tire layer 14 located further inward relative to the tread 12. The vehicle pneumatic tire 10 also includes a tire carcass and belt plies, which are not shown in Fig. 1 for clarity. A porous noise-dampening layer 16 is arranged centrally beneath the tread 12. This layer consists essentially entirely of a plurality of rubber particles 18 bonded together by means of a reactive adhesive to create the porous noise-dampening layer 16.

[0083] In the example of Fig. 1, the rubber particles consist essentially entirely of a rubber material which was produced from the tread 12 in the course of a retreading process of a vehicle pneumatic tire 10 of the same type.

[0084] The noise-dampening layer 16 shown in Fig. 1 has an average thickness of about 40 mm and a density of about 0.6 g / cm³. 3 and extends over the entire circumference of the vehicle pneumatic tire 10, wherein the noise damping layer 16 is arranged directly on the inner tire layer 14 with the same adhesive which also bonds the rubber particles 18 together.

[0085] Fig. 2 shows a schematic visualization of the inventive method by which the vehicle pneumatic tire 10 of Fig. 1 can be manufactured. Fig. 2 shows a spray device 20 which applies the rubber particles 18, which have been previously coated with the adhesive, in layers to the inside of the vehicle pneumatic tire 10, relative to the vehicle pneumatic tire 202401054.

[0086] 20

[0087] 10 is moved to shape the noise damping layer 16 with the desired thickness.

[0088] 202401054

[0089] 21

[0090] Reference symbol list

[0091] 10 vehicle pneumatic tires

[0092] 12 treads

[0093] 14 Tire inner layer 16 Noise damping layer

[0094] 18 rubber particles

[0095] 20 spray device

Claims

202401054 22 Claims 1. Method for manufacturing a vehicle pneumatic tire (10), comprising: i) a radially outer tread (12), ii) an inner tire layer (14) located radially further inward relative to the tread (12), and iii) a porous noise-dampening layer (16) located radially further inward relative to the inner tire layer (14), comprising the step: a) manufacturing the porous noise-dampening layer (16) by metallurgically bonding a plurality of rubber particles (18) by means of an adhesive, wherein the rubber particles (18) consist at least partially of a rubber material.

2. Method according to claim 1, wherein the production of the porous noise-damping layer (16) by material-bonding connection of the plurality of rubber particles (18) takes place at least partially before the application of the porous noise-damping layer (16) in the vehicle pneumatic tire (10).

3. Method according to one of claims 1 or 2, wherein the production of the porous noise-dampening layer (16) takes place on the inside of the vehicle pneumatic tire (10).

4. Method according to any one of claims 1 to 3, wherein the rubber particles (18) consist of a mass fraction of 70% or more of the rubber material. 202401054 23 5. Method according to any one of claims 1 to 4, wherein the rubber particles (18) consist at least partially of a recycled rubber material.

6. Method according to any one of claims 1 to 5, wherein the adhesive is a reactive adhesive.

7. Method according to any one of claims 1 to 6, wherein the production of the porous noise-dampening layer (16) comprises the layer-by-layer application of layers of rubber particles (18) until the desired final thickness of the porous noise-dampening layer (16) is reached.

8. Method according to any one of claims 1 to 7, wherein the production of the porous noise-dampening layer (16) comprises the layer-by-layer application of layers to rubber particles (18) pre-coated with adhesive, and / or wherein the production of the porous noise-dampening layer (16) comprises the layer-by-layer application of layers to rubber particles (18), wherein the adhesive is applied to the applied layers after each application.

9. Method according to any one of claims 1 to 8, wherein producing the porous noise-dampening layer (16) comprises spraying the rubber particles (18) with a spraying device (20). 202401054 24 10. Method according to any one of claims 1 to 9, wherein the porous noise-dampening layer (16) consists of the rubber particles (18) and the adhesive to a mass fraction of 80% or more, based on the mass of the porous noise-dampening layer (16).

11. Method according to any one of claims 1 to 10, wherein the porous noise-dampening layer (16) has a mean porosity in the range of 30 to 90%.

12. Method according to any one of claims 1 to 11, wherein the porous noise-dampening layer (16) is an open-pore noise-dampening layer (16).

13. Vehicle pneumatic tire (10), comprising: i) a radially outer tread (12), ii) an inner tire layer (14) located radially further inward relative to the tread (12), and iii) a porous noise-dampening layer (16) located radially further inward relative to the inner tire layer (14), wherein the porous noise-dampening layer (16) comprises a plurality of rubber particles (18) which are connected to each other by a material bond using an adhesive, wherein the rubber particles (18) consist at least partially of a rubber material.

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