DE102022209495A1 - Method for incorporating electronic components into a rubber product - Google Patents

Abstract

The invention relates to a method for introducing electronic components (10) into a rubber product (12), comprising the method steps: a) producing or providing an electronic component (10), b) producing or providing a first rubber component (14) of the rubber product ( 12), as well as one of the method steps: c1) placing the electronic component (10) on the first rubber component (14) and covering the placed electronic component (10) with a vulcanizable rubber mixture (16), or c2) encasing the electronic component (10 ) with a vulcanizable rubber mixture (16) and placing the encased electronic component (10) on the first rubber component (14), to obtain a component arrangement (18) in which the electronic component (10) is separated from the first rubber component (14) and from the vulcanizable rubber mixture (16) is essentially completely surrounded by the mold, the vulcanizable rubber mixture (16) having a Mooney viscosity ML (1 + 3 / 100 ° C) according to DIN 53523-2-1991 of 50 MU or less.

Description

The invention relates to a method for introducing electronic components into a rubber product and a method based thereon for producing a vulcanized rubber product with an electronic component. Also disclosed is a vulcanized rubber product that can be produced using the corresponding process, in particular a vehicle tire.

As technological developments have progressed, vehicle tires have also developed from relatively simple rubber products to high-tech products. An important part of this progress is the development of providing vehicle tires with additional electronic components in order to facilitate or enable the handling and, in particular, the monitoring of the vehicle tires. In addition to tire-integrated sensor units, electronic identification units, such as RFID chips, which are also referred to as RFID tags and which can be inserted into vehicle tires, play an important role, as is the case, for example EP 3620312 A1 or the DE 102018220562 A1 is revealed.

For many electronic components that are already used in vehicle tires today, especially for electronic identification units such as RFID chips, it is important in many cases for error-free functionality that they are attached to the correct position in the vehicle tire. For many sensor-based electronic components, such as acceleration sensors, precise positioning is important to obtain accurate and comparable sensor data. Even more important is accurate positioning in the vehicle tire for electronic components that are intended to be read later from outside the tire, as is the case with RFID tags, for example, so that they can be read reliably using short-range communication methods, for example handheld readers.

Despite the advantages and expanded possibilities that the use of electronic components in vehicle tires enables, the electronic components introduced also represent potential weak points in the tire composite produced. In accordance with expert understanding, the aim is often to have the vehicle tire largely rotationally symmetrical over the entire circumference to be formed as evenly as possible. An electronic component acting as a foreign body between the other tire parts can have a locally detrimental effect on the tire properties or durability. This applies in particular if the electronic component, due to its non-negligible volume and a three-dimensional structure, results in cavities and air pockets remaining around the component, which can adversely affect the local bond strength and the mechanical properties in the area of the electronic component.

The need described above for precise positioning of electronic components in a vehicle tire as well as the problems that can arise from the introduction of electronic components are particularly evident in vehicle tires. However, the expert in the field of rubber processing understands that the underlying problem also applies in a corresponding way to all other rubber products that are to be provided with electronic sensors, especially if they are also exposed to strong mechanical loads during later use.

In order to address the problem described above, in many cases electronic components in the prior art are not introduced into the blank of a rubber product in isolation, but are previously arranged between two layer-shaped rubber components according to the so-called “sandwich” principle and laminated between them. In many cases, the rubber intermediate products obtained can be placed more reliably in the rubber product. In addition, from a manufacturing perspective, these rubber intermediate products in many cases allow at least a reduction in the cavities formed around the electronic component, since the relatively small rubber layers can be more easily adapted to the shape of the electronic component, so that compared to embodiments in which the electronic component is directly, for example between two layer-shaped materials of a vehicle tire, for example between the carcass and the sidewall, result in advantages in terms of mold enclosure.

Even if the solution of rubber intermediate products with a “sandwich” structure used in the prior art enables an improvement in many cases, the amount of work associated with the positive surrounding of the electronic component as well as the maximum achievable positive fit is perceived as inadequate in many cases. In addition, with this solution it must be ensured that the resulting “sandwich” structure is correctly laminated and the composite created in this way cannot cause any further weakening in the later rubber product.

A middle ground between the production of a rubber intermediate product and the direct introduction of the electronic component into a rubber product is a procedure in which the electronic component is not first laminated between two rubber layers, but is attached between the rubber product and only one rubber layer, as is shown, for example, in the US 2006/164250 A1 is revealed. However, according to the inventors' assessment, this is particularly suitable for the external attachment of electronic components, for example to the inner layer of a tire, and is less preferred in view of the achievable positive fit around the electronic component and with regard to the avoidance of air pockets.

In addition to the established solutions described above, there are also other solution concepts for the introduction of electronic components into rubber products in the prior art, which, according to the inventors' assessment, are aimed more at other aspects. For example, the reveals US 9,884,462 B2 an apparatus for tires in which an electronic component is arranged between two specifically shaped cover layers, the cover layers forming a recess in which the electronic component is surrounded by a middle layer which serves the purpose of electrically isolating the electronic component from the surrounding rubber serves. In this respect, an improved function is expected due to the electrical insulation of the electronic component. According to the inventors, however, this solution is less preferred in terms of the achievable homogeneity of the rubber product and in terms of avoiding defects in the composite of the rubber product, since the middle layer is not made of rubber and is therefore together with the electronic component, even if it should enclose it well , creates a localized area with physical-chemical and mechanical properties that can differ significantly from those of the surrounding rubber product and, for example, can worsen the bond strength under mechanical stress due to different stiffnesses. In addition, according to the inventors, this solution for introducing electronic components is also disadvantageous from a manufacturing perspective, since other components such as epoxies, silicones and urethanes, which are used in the rubber processing industry, especially in the area of tire production, should be used for the electrically insulating middle layer. are not used regularly and therefore place increased demands on the storage and processing infrastructure.

The primary object of the present invention was to eliminate or at least reduce the disadvantages of the prior art described above.

In particular, it was the object of the present invention to provide a method for introducing electronic components into a rubber product, with which the electronic components in the rubber product can be positioned reliably and precisely.

In addition, it was an object of the present invention that the method to be specified should enable the introduction of electronic components into a rubber product with the lowest possible level of air inclusions and structural defects.

Against this background, it was an object of the present invention to be able to produce rubber products with the method to be specified which, despite an internal electronic component, have excellent bond strength, especially under strong mechanical stress, and the most homogeneous property profile of the physico-chemical and show mechanical properties.

It was a further object of the present invention that the method to be specified should be able to be carried out in a more time- and cost-efficient manner than the methods known from the prior art, in particular the time required to avoid defects in the rubber product induced by the electronic component , should be minimized.

It was a desirable requirement that the process to be specified should be able to be produced using materials and manufacturing techniques that are already regularly used in the rubber processing industry, and it was particularly desirable that no additional storage and processing infrastructure was required for the handling of Components that are rather unusual in the rubber industry are required.

The inventors of the present invention have now recognized that the tasks described above can surprisingly be achieved if, when introducing electronic components into a rubber product, a vulcanizable rubber mixture with low viscosity is used in order to contain the electronic components to surround the cal component with an optimal positive fit, as defined in the claims. In this way, air pockets around the electronic component can be reliably prevented and an optimal positive fit can be achieved with little production effort. At the same time, the rubber material that can be produced from this vulcanizable rubber mixture by vulcanization does not differ or does not differ significantly from the surrounding components of the rubber product in terms of physical-chemical and mechanical properties, so that no unwanted weak point is created in the composite of the rubber product even under strong mechanical loads.

In this way it can be ensured that the electronic component is safely, completely and precisely enclosed with the rubber mass of the later rubber product and that no possible air inclusions occur, with this corresponding method being advantageously applicable to all types of rubber products, even if, in the opinion of the inventors The greatest application potential arises in the area of vehicle tires. In this respect, the inventors have succeeded in identifying such embodiments of the use of low-viscosity vulcanizable rubber mixtures that are particularly practical and advantageous from an application technology perspective.

Further state of the art is, for example, in US 6613609 B1 , the EP 1 855 897 B1 as well as the EP 3 632 666 B1 disclosed.

The above-mentioned objects are thus achieved by the subject matter of the invention, as defined in the claims. Preferred embodiments according to the invention result from the subclaims and the following statements.

Such embodiments, which are referred to below as preferred, are combined in particularly preferred embodiments with features of other embodiments designated as preferred. Combinations of two or more of the embodiments described below as particularly preferred are therefore very particularly preferred. Also preferred are embodiments in which a feature of one embodiment that is designated as preferred to some extent is combined with one or more further features of other embodiments that are designated as preferred to some extent. Features of preferred rubber products result from the features of preferred processes.

Insofar as mass proportions are specified below, these are each specified in the industry-standard manner as combined mass proportions of one or more components, which expresses that the mass proportion of the correspondingly designed components taken together meets the corresponding criteria. The specification used here is phr (parts per hundred parts of rubber by weight) which is the usual quantity specification for mixture recipes in the rubber industry, which determines the mass proportions of the components in the rubber mixture based on the mass of the high molecular weight (weight average molecular weight distribution Mw) present in the rubber mixture GPC greater than 60,000 g/mol) rubbers are specified, with the combined mass fraction of the high molecular weight rubbers in the rubber mixture corresponding to 100 phr. The weight-average molecular weight Mw and is determined using gel permeation chromatography in accordance with DIN 55672-1:2016-03 (GPC with tetrahydofuran as eluent, polystyrene standard; size exclusion chromatography).

• a) Herstellen oder Bereitstellen einer elektronischen Komponente,
• b) Herstellen oder Bereitstellen eines ersten Kautschukbauteils des Kautschukproduktes, sowie einen der Verfahrensschritte:
• c1) Auflegen der elektronischen Komponente auf das erste Kautschukbauteil und Bedecken der aufgelegten elektronischen Komponente mit einer vulkanisierbaren Kautschukmischung, oder
• c2) Einhüllen der elektronischen Komponente mit einer vulkanisierbaren Kautschukmischung und Auflegen der eingehüllten elektronischen Komponente auf das erste Kautschukbauteil,

zum Erhalt einer Komponentenanordnung, in der die elektronische Komponente vom erste Kautschukbauteil und von der vulkanisierbaren Kautschukmischung im Wesentlichen vollständig formumschließend umgeben ist,
wobei die vulkanisierbare Kautschukmischung eine Mooney-Viskosität ML (1+3 / 100 °C) gemäß DIN 53523-2-1991 von 50 MU oder weniger aufweist.The invention relates in particular to a method for introducing electronic components into a rubber product, comprising the method steps:

• a) producing or providing an electronic component,
• b) producing or providing a first rubber component of the rubber product, as well as one of the process steps:
• c1) placing the electronic component on the first rubber component and covering the placed electronic component with a vulcanizable rubber mixture, or
• c2) encasing the electronic component with a vulcanizable rubber mixture and placing the encased electronic component on the first rubber component,

to obtain a component arrangement in which the electronic component is essentially completely surrounded by the first rubber component and by the vulcanizable rubber mixture in a form-enclosing manner,
where the vulcanizable rubber mixture has a Mooney viscosity ML (1+3 / 100 ° C). DIN 53523-2-1991 of 50 MU or less.

The method according to the invention serves to introduce electronic components into a rubber product. The expert understands that the rubber product is in principle can be any type of rubber product. In particular, however, two different embodiments are included.

The rubber product into which the electronic component is introduced can initially be a rubber product that is intended for the corresponding end use, for example a belt or a vehicle tire. In this case, the method according to the invention is used to arrange the electronic component reliably and precisely between the components of this rubber product through the advantageous use of a vulcanizable rubber mixture with a low viscosity.

The second particularly relevant embodiment is that the rubber product is an intermediate rubber product, which can then be introduced as a kind of semi-finished product in the production of another rubber product. In particular, the rubber product can be a layer composite with a “sandwich” structure in which the electronic component is fixed, and which is similar in basic principle to the rubber intermediate product described above, but obtained with significantly less manufacturing effort and an improved positive fit and improved bond strength can be. The person skilled in the art understands that these two configurations are also preferred in their own right.

The method according to the invention is defined above in relation to the introduction of only one electronic component. However, the person skilled in the art understands that when producing rubber products, the method according to the invention can also be used several times, for example to introduce two or more, preferably three or more, electronic components into the rubber product.

In process step a), the electronic component to be introduced is first manufactured or provided, with provision by purchasing the electronic component from a specialized provider likely to be the more practical option for most rubber processing companies.

It can be seen as an advantage of the method according to the invention that, as a result of its operating principle, it is very flexible with regard to the technical nature of the electronic component, with electronic sensor units and electronic identification units in particular benefiting from the precise positioning and good positive locking that can be achieved in the method according to the invention , particularly benefit. Since these corresponding electronic components also have the highest practical relevance, particularly for use in vehicle tire production, a method according to the invention is preferred, wherein the electronic component is a sensor unit or an electronic identification unit, preferably an electronic identification unit. A method according to the invention is preferred, wherein the electronic identification unit comprises an electronic transmitting and receiving device, the electronic transmitting and receiving device preferably communicating by means of electromagnetic radiation, the electronic identification unit particularly preferably being an RFID chip, particularly preferably with a dipole antenna .

In method step b), a first rubber component of the rubber product is produced or provided. The person skilled in the art understands that a corresponding first rubber component will comprise a rubber-containing mixture, which in the context of the present invention is referred to as a vulcanizable component rubber mixture to distinguish the vulcanizable rubber mixture. In other words, it is a method according to the invention, wherein the first rubber component or the second rubber component disclosed below comprise a vulcanizable component rubber mixture.

In contrast to the electronic components, in practice the first rubber component will usually be produced by a rubber processing company itself, for example by surrounding reinforcements with the vulcanizable component rubber mixture as a rubber coating in suitable manufacturing plants, whereby the presence of reinforcements in the first rubber component is not necessary and in particular in the production described above of a rubber intermediate product that can be used as a semi-finished product with an electronic component laminated between two rubber layers is unlikely to be used in practice. Accordingly, a method according to the invention is preferred, especially for direct introduction into vehicle tires, wherein the first rubber component and/or the second rubber component, preferably both rubber components, comprise a plurality of reinforcements embedded in the component rubber mixture.

While in the prior art, for example in the US 2006/164250 A1 , in many cases it is taught to arrange the electronic component between vulcanizable component rubber mixtures that are as similar as possible, the inventors have recognized that the advantages of the invention The process results precisely from the use of a vulcanizable rubber mixture, which differs significantly in terms of its viscosity from the typical vulcanizable component rubber mixtures that are usually used in the production of rubber products. The person skilled in the art understands that the method according to the invention makes use of the fact that a low-viscosity vulcanizable rubber mixture can surround an electronic component particularly easily and particularly reliably in a substantially form-fitting manner even if this electronic component has a complex three-dimensional structure, for example as a result of specifically structured antennas. In this respect, the inventors suggest that it is also particularly advantageous from an application perspective to design the vulcanizable rubber mixture with a particularly low viscosity so that the positive fit around the electronic component is possible particularly efficiently, with the functional lower limit of the viscosity automatically resulting from the requirement, that the vulcanizable rubber mixture must essentially completely surround the electronic component in the component arrangement obtained. In this respect, the functional lower limit of viscosity depends heavily on the design of the rubber components. Since the Mooney viscosity that is common in the rubber industry would not be optimally suitable for characterizing very low viscosities, it is appropriate not to define any artificial lower limits. A method according to the invention is preferred, wherein the vulcanizable rubber mixture has a Mooney viscosity ML (1+3/100 ° C) according to DIN 53523-2-1991 of 45 MU or less, preferably 40 MU or less, particularly preferably 35 MU or less, having.

The person skilled in the art understands that the advantages of the method according to the invention are particularly pronounced when the rubber components between which the electronic component is to be arranged themselves comprise a high-viscosity vulcanizable rubber mixture, since in this case regularly without the use of the low-viscosity vulcanizable rubber mixture particularly poor positive locking would be possible and the absolute improvement that results from the procedure according to the invention would be particularly pronounced. A method according to the invention is therefore preferred, wherein the vulcanizable component rubber mixture has a Mooney viscosity M L (1 +3 / 100 ° C) according to DIN 53523-2-1991 of 55 MU or more, preferably 60 MU or more, particularly preferably 65 MU or more , having.

In more general terms, a method according to the invention is preferred, wherein the vulcanizable rubber mixture and the vulcanizable component rubber mixture of the first rubber component are different, in particular with regard to viscosity.

The method according to the invention uses the vulcanizable rubber mixture with the low viscosity in one of two variants, although it is in principle conceivable to combine these variants with one another in whole or in part.

In method step c1), the electronic component to be introduced is first placed on the first rubber component and consequently has a certain contact surface with the first rubber component. Subsequently, the electronic component placed in this way and thus ultimately also a part of the underlying surface of the first rubber component is covered with the low-viscosity vulcanizable rubber mixture, whereby due to the low viscosity of the vulcanizable rubber mixture, the electronic component can be efficiently surrounded in a form-fitting manner, so that it is partially covered by the surface of the first rubber component and beyond that is surrounded by the vulcanizable rubber mixture, so that together a form-fitting enclosure is obtained. This means, at least in the absence of a second rubber component, the use of which is disclosed below, in other words, that it is a method according to the invention, the covering of the applied electronic component with the vulcanizable rubber mixture in process step c1) taking place in such a way that the electronic Component, apart from the contact surface on the first rubber component, is essentially completely positively surrounded by the vulcanizable rubber mixture.

According to the inventors' assessment, the process is carried out according to process step c1), i.e. H. The downstream covering of an electronic component, which is placed on top of it, can in many cases be carried out particularly easily and in a timely and cost-efficient manner from a manufacturing point of view. In addition, the position and orientation of the electronic component in the rubber product to be produced can be adjusted particularly precisely. Accordingly, a method according to the invention is preferred for many applications, the method comprising method step c1).

As an alternative method, the inventors suggest that the electronic component can be coated with the vulcanizable rubber mixture before it is applied to the surface of the first rubber component in order to protect it jointly create a network created in this way. Depending on the viscosity of the vulcanizable rubber mixture, it is possible to create an at least roughly dimensionally stable composite that does not completely flow, at least for the duration of the application process, or alternatively to disperse the electronic component in a largely liquid vulcanizable rubber mixture and apply this dispersion together. A corresponding composite can be made, for example, by introducing the electronic component and the vulcanizable rubber mixture into a separate mold, with a prefabricated, encased electronic component being obtained as an intermediate product in a process not dissimilar to chocolate production, which is suitable for use in the process according to the invention with the process control is suitable according to process step c2).

In contrast to the process management with process step c1), the process control according to process step c2) is, in the opinion of the inventors, particularly suitable for those components that have a very complex three-dimensional structure and which would be feared if they were previously placed on the top of the first rubber component that, as a result of the structure of the electronic component, cavities arise between the surface of the first rubber component and the electronic component, which would not or would not be completely accessible from the outside for the subsequently applied vulcanizable rubber mixture. Because of the introduction of the electronic component into the vulcanizable rubber mixture before application, the process procedure with process step c2) is, in the opinion of the inventors, more suitable for components that are less demanding in terms of the precision of the arrangement and alignment, since these are due to the previous introduction in the vulcanizable rubber mixture can be made more difficult under certain circumstances. A method according to the invention is therefore preferred for certain applications, the method comprising method step c2).

Preference is given to a method according to the invention, wherein the electronic component is enveloped with the vulcanizable rubber mixture in method step c2) in such a way that the electronic component is essentially completely surrounded by the vulcanizable rubber mixture in a form-fitting manner. Additionally or alternatively, a method according to the invention is preferred, wherein the encasing of the electronic component with the vulcanizable rubber mixture in process step c2) takes place in a separate form, a prefabricated encased electronic component with predetermined dimensions being obtained as an intermediate product.

The person skilled in the art understands that, for a sensible implementation of the method according to the invention, it is expedient to place the electronic component sufficiently centrally on the first rubber component so that it does not protrude beyond the first rubber component at any point, in which cases covering with the vulcanizable rubber mixture, particularly when using particularly low-viscosity vulcanizable rubber mixtures, could be made more difficult and could possibly require the use of further manufacturing steps. Accordingly, a method according to the invention is particularly effective, with the placement in method step c1) or c2) being carried out in such a way that the first rubber component protrudes beyond the electronic component on all sides in the plan view.

The inventors suggest that the vulcanizable rubber mixture should be used with a sufficiently large volume to ensure reliable coverage and positive enclosure of the electronic component. Despite the high compatibility of the vulcanizable rubber mixture used with the other components of the rubber product, which also use vulcanizable rubber mixtures, the inventors suggest that, on the other hand, with a view to the properties being as homogeneous as possible in the later rubber product, it is advisable not to use too much use a low-viscosity vulcanizable rubber mixture. In summary, preference is given to a method according to the invention, wherein the vulcanizable rubber mixture in process step c1) or c2) is used to cover or encase the electronic component in a volume in the range from 1.0*V _EK to 15.0*V _EK , preferably in Range from 1.5*V _EK to 10.0*V _EK , particularly preferably in the range from 2.0*V _EK to 5.0*V _EK , is used, where V _EK is the volume of the electronic component.

• d1) Ausformen der vulkanisierbaren Kautschukmischung in der Komponentenanordnung, wobei das Ausformen bevorzugt das Glätten und/oder Ausstreichen umfasst.

The person skilled in the art understands that the component arrangement obtained in the method according to the invention can, at least in principle, be vulcanized together with any other components of the rubber product present in order to obtain a vulcanized rubber product in which the electronic component is surrounded by a rubber material in a particularly form-fitting manner. However, the person skilled in the art understands that such a product obtained by vulcanization runs at least the risk of having an uneven surface which may be caused by the vulcanized rubber mixture. For many this is rubber product is not only less preferred for aesthetic reasons, but can also have a negative impact on other parameters such as cleanability or flow resistance. Accordingly, the inventors suggest that the vulcanizable rubber mixture in the component arrangement should at least be shaped in a targeted manner, with smoothing in particular being particularly advantageous in order to avoid the problems described above. Accordingly, preference is given to a method according to the invention, additionally comprising the method step:

• d1) molding the vulcanizable rubber mixture in the component arrangement, the molding preferably comprising smoothing and/or spreading.

• d2) Abdecken der Komponentenanordnung mit einem zweiten Kautschukbauteil, wobei das Abdecken so erfolgt, dass die elektronische Komponente zwischen dem ersten Kautschukbauteil und dem zweiten Kautschukbauteil angeordnet ist.

Even if the above-described molding of the vulcanizable rubber mixture is already associated with advantages, the result after vulcanization is still a rubber product whose surface is formed in sections by the vulcanized vulcanizable rubber mixture. However, since the vulcanizable rubber mixture will in most cases be optimized for optimal positive fit with the electronic component rather than for optimal durability, the inventors believe that it is important with regard to the durability of the resulting rubber product, especially with regard to resistance to environmental influences and mechanical stresses in the area of the electronic component are advantageous if they are also covered with another rubber component before vulcanization. In this respect, the person skilled in the art understands that covering the component arrangement with a second rubber component as a result of pressure application will usually also indirectly include the molding of the vulcanizable rubber mixture between the first and the second rubber component. This advantageously results in an electronic component which is enclosed between the first and the second rubber component and is reliably surrounded in a form-fitting manner by the vulcanizable rubber mixture arranged therebetween. A process according to the invention is particularly preferred, additionally comprising the process step:

• d2) Covering the component arrangement with a second rubber component, the covering being carried out in such a way that the electronic component is arranged between the first rubber component and the second rubber component.

• d1) Ausformen der vulkanisierbaren Kautschukmischung in der Komponentenanordnung, wobei das Ausformen bevorzugt das Glätten und/oder Ausstreichen umfasst, und/oder
• d2) Abdecken der Komponentenanordnung mit einem zweiten Kautschukbauteil, wobei das Abdecken so erfolgt, dass die elektronische Komponente zwischen dem ersten Kautschukbauteil und dem zweiten Kautschukbauteil angeordnet ist.

Overall, a method according to the invention is preferred, additionally comprising one or both of the method steps:

• d1) molding the vulcanizable rubber mixture in the component arrangement, the molding preferably comprising smoothing and/or spreading, and/or
• d2) Covering the component arrangement with a second rubber component, the covering being carried out in such a way that the electronic component is arranged between the first rubber component and the second rubber component.

The person skilled in the art understands that in the embodiment described above using a second rubber component, the pressing of the second rubber component can be so pronounced that the vulcanizable rubber mixture is displaced in places and direct contact occurs between the electronic component and the second rubber component. As a result, when using method step d2), either the component arrangement described above, in which the electronic component is surrounded by the first rubber component and the vulcanizable rubber mixture in a substantially completely mold-enclosing manner, is obtained, or alternatively a component arrangement in which the electronic component is surrounded by the first rubber component, is essentially completely surrounded by the second rubber component and by the vulcanizable rubber mixture.

In particular, using the process procedure with process step d2), rubber intermediate products can be obtained as described above for use in other rubber products, such as rubber laminates with electronic components arranged in between. However, since the advantageous use of a low-viscosity vulcanizable rubber mixture advantageously enables a good positive fit even without the prior production of such a laminate, it is preferred for many applications if the process procedure with process step d2) is used to insert the electronic component directly into a to introduce the final rubber product. Because of the particular suitability of the method according to the invention for introducing electronic components into vehicle tires, it is particularly preferred that the rubber product into which the electronic component is directly introduced is a vehicle tire blank, which is later transferred into a vehicle tire by means of vulcanization can. Accordingly, a method according to the invention is preferred, wherein the first rubber component is a vehicle tire component, preferably a carcass ply or a reinforcement layer, wherein the first rubber component is preferably a component of a vehicle tire blank, wherein the first rubber component is preferably produced or provided on a tire building drum. Particularly preferred is a method according to the invention, wherein the placement in method step c1) or c2) is carried out in such a way that the electronic component is arranged in the side wall area of a vehicle tire blank.

It can be seen as an advantage of the method according to the invention that it is very flexible with regard to the rubbers used in the vulcanizable rubber mixture or also in the vulcanizable component rubber mixture. A method according to the invention is relevant for essentially all purposes, wherein the vulcanizable rubber mixture and/or the vulcanizable component rubber mixture, preferably the vulcanizable rubber mixture and the vulcanizable component rubber mixture, comprise at least one diene rubber. An example in this respect is a method according to the invention, where the diene rubber is selected from the group consisting of natural polyisoprene (NR), synthetic polyisoprene (IR), butadiene rubber (BR), solution-polymerized styrene-butadiene rubber (SSBR) and emulsion-polymerized styrene-butadiene -Rubber (ESBR).

The inventors have recognized that the desired low viscosities of the vulcanizable rubber mixture can be achieved in an advantageous manner, particularly if the vulcanizable rubber mixture includes polymers with lower molecular weights in addition to high molecular weight rubbers, with mass fractions of up to 50 phr being seen as advantageous. Against this background, preference is given to a method according to the invention, wherein the vulcanizable rubber mixture comprises one or more polymers, the polymer being selected from the group consisting of polymers with a weight-average molecular weight Mw, measured by GPC, of 50,000 g/mol or less, preferably of 40,000 g/mol or less, particularly preferably 30,000 g/mol or less, the combined mass fraction of the polymers in the vulcanizable rubber mixture preferably in the range from 1 to 50 phr, particularly preferably in the range from 5 to 45 phr, very particularly preferably in Range from 10 to 40 phr, based on the mass of the vulcanizable rubber mixture.

Both the vulcanizable rubber mixture and the vulcanizable component rubber mixtures can contain usual fillers in the usual amounts, in addition to soot also amorphous silicon dioxide, in particular in the form of pyrogenic amorphous silicon dioxide or precipitated amorphous silicon dioxide, so-called pyrogenic silica or precipitated silica (after the English Expression also referred to as “silica”) comes into question. Preference is given to a method according to the invention, wherein the vulcanizable rubber mixture and/or the vulcanizable component rubber mixture, preferably the vulcanizable rubber mixture and the vulcanizable component rubber mixture, contain one or more fillers in a combined mass fraction in the range from 40 to 180 phr, preferably in the range from 50 to 150 phr, particularly preferably in the range from 60 to 120 phr.

While the prior art according to the US 9884462 B2 suggests deliberately incorporating electronic components into electronically insulating middle layers, the inventors of the present invention have found that this is not necessary for most electronic components. Rather, even when using more conductive vulcanizable rubber mixtures, ie vulcanizable rubber mixtures with a higher carbon black content, the inventors were unable to determine any significant restriction in the function of the electronic components. Rather, the use of carbon black makes it possible to specifically optimize the physical-chemical and mechanical properties of the vulcanizable rubber mixture and the rubber materials obtained from it by means of vulcanization, whereby in particular advantageous compatibility with the vulcanizable component rubber mixtures can be achieved. Preference is given to a method according to the invention, wherein the vulcanizable rubber mixture comprises one or more carbon blacks in a combined mass fraction in the range of 5 phr or more, preferably 10 phr or more, particularly preferably 15 phr or more.

• e) Vulkanisieren der Komponentenanordnung zum Erhalt einer vulkanisierten Komponentenanordnung, wobei das Vulkanisieren so erfolgt, dass die vulkanisierte Kautschukmischung in der vulkanisierten Komponentenanordnung stoffschlüssig mit dem vulkanisierten ersten Kautschukbauteil verbunden ist.

The person skilled in the art understands that in the method according to the invention, an electronic component is introduced into a rubber product, which is still a blank which has not yet been converted into a vulcanized rubber product by means of vulcanization, using the previously existing vulcanizable rubber mixtures and vulcanizable component rubber mixtures were converted into vulcanized rubber mixtures or vulcanized component rubber mixtures, ie into rubber materials. The invention therefore also relates to a method for producing a vulcanized rubber product with an electronic component, comprising the method steps of the method according to the invention for introducing electronic components into a rubber product, as well as the method step:

• e) vulcanizing the component arrangement to obtain a vulcanized component arrangement, the vulcanization being carried out in such a way that the vulcanized rubber mixture is in the vulcanized component arrangement is cohesively connected to the vulcanized first rubber component.

Vulcanization is a work step that is well known to those skilled in the field of rubber processing. For this purpose, standard vulcanization conditions can be used within the scope of the method according to the invention, which the person skilled in the art can easily adapt to the vulcanizable rubber mixtures or vulcanizable component rubber mixtures that he uses. What is relevant for most cases is a method according to the invention, wherein the vulcanization takes place in a vulcanization mold, preferably using a vulcanization bellows. A method according to the invention for producing a rubber product is preferred, with the vulcanization taking place at a temperature in the range from 130 to 200 ° C, preferably in the range from 150 to 180 ° C.

Vulcanization produces a vulcanized rubber product, i.e. H. a rubber product, in the interior of which an electronic component is arranged, which, however, is surrounded by rubber materials in a particularly positive manner as a result of the method according to the invention, so that the corresponding vulcanized rubber product has an advantageous bond strength and a low level of air inclusions.

Accordingly, a vulcanized rubber product is also disclosed, preferably produced or producible using the method according to the invention for producing a rubber product with an electronic component, comprising at least one electronic component inside, the electronic component being essentially completely surrounded by a vulcanized rubber mixture. A corresponding rubber product is preferred, the rubber product being a vehicle tire, preferably a pneumatic vehicle tire.

• 1 eine schematische Visualisierung der Herstellung eines Halbzeuges durch Laminierung einer elektronischen Komponente zwischen zwei Kautschukschichten mit einem nicht erfindungsgemäßen Verfahren;
• 2 eine schematische Visualisierung des Verfahrensschrittes c1) des erfindungsgemäßen Verfahrens in einer bevorzugten Ausführungsform;
• 3 eine schematische Visualisierung des Verfahrensschrittes c2) des erfindungsgemäßen Verfahrens in einer bevorzugten Ausführungsform;
• 4 eine schematische Visualisierung des Verfahrensschrittes d1) eines bevorzugten erfindungsgemäßen Verfahrens;
• 5 eine schematische Visualisierung des Verfahrensschrittes d2) des bevorzugten erfindungsgemäßen Verfahrens; und
• 6 eine schematische Darstellung eines mit dem erfindungsgemäßen Verfahren zu erhaltenen Kautschukproduktes.

The invention and preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying figures. Show:

• 1 a schematic visualization of the production of a semi-finished product by lamination of an electronic component between two rubber layers using a method not according to the invention;
• 2 a schematic visualization of method step c1) of the method according to the invention in a preferred embodiment;
• 3 a schematic visualization of method step c2) of the method according to the invention in a preferred embodiment;
• 4 a schematic visualization of method step d1) of a preferred method according to the invention;
• 5 a schematic visualization of method step d2) of the preferred method according to the invention; and
• 6 a schematic representation of a rubber product to be obtained using the process according to the invention.

1 For subsequent comparison with the method according to the invention, first shows a schematic representation of the method known from the prior art for producing a rubber intermediate product for further processing in a rubber product 12, in which an electronic component 10 is initially placed on a first without the use of a vulcanizable rubber mixture 16 Rubber component 14 is placed and then covered with a second rubber component 20. The structure obtained can be laminated, for example, by applying force, whereby, according to the prior art, an attempt must be made not only to create sufficient bond strength, but also to largely surround the electronic component 10 in such a way that there are as few air pockets as possible.

2 In contrast, shows a schematic representation of process step c1) of the process according to the invention in a preferred embodiment. Here, the electronic component 10 is first also placed on the surface of a first rubber component 14, which is based on the example not according to the invention 1 can be a rubber layer which comprises a vulcanizable component rubber mixture, but is free of any reinforcements.

In 2 is shown how, starting from this basic arrangement, the electronic component 10 and the underlying surface of the first rubber component 14 are covered with the vulcanizable rubber mixture 16, so that the electronic component 10 in the resulting component arrangement 18 at all points where it is not covered by the first rubber component 14 is contacted, is essentially completely surrounded by the vulcanizable rubber mixture.

3 shows a schematic representation of the alternative process step c2), which is in Ultimately in one with the out 2 obtained component arrangement 18 results in a comparable final state. In contrast to that in 2 In the visualized procedure, however, the electronic component 10 is first covered with the vulcanizable rubber mixture 16, so that it is essentially completely surrounded by the vulcanizable rubber mixture 16 before it is placed on the surface of the first rubber component 14, which can be done, for example, in a separate form to obtain a pre-assembled encased electronic component 10 with predetermined dimensions. By applying this prefabricated encased electronic component 10 to the surface of the first rubber component 14, a component arrangement 18 is in turn obtained, in which the electronic component 10 is essentially completely surrounded by the first rubber component 14 and the vulcanizable rubber mixture 16 in a form-enclosing manner.

The 4 now shows how starting from the according 2 or 3 to obtain component arrangement 18 using a method step d1), a component arrangement 18 can be obtained in which the vulcanizable rubber mixture 16 was formed in order to obtain a flatter layer with a surface that is as smooth as possible without destroying the advantageous cover of the electronic component 10 .

5 then visualizes how starting from the in 4 manufactured component arrangement 18 with the molded vulcanizable rubber mixture 16, a preferred component arrangement 18 is obtained, in which it is also covered with a second rubber component 20, the second rubber component 20 being identical to the first rubber component 14 in the example shown. The resulting component arrangement 18 is similar to that in 1 shown structure according to the prior art, but has considerable advantages due to the vulcanizable rubber mixture 16 which is arranged between the first rubber component 14 and the second rubber component 20 and which advantageously surrounds the electronic component 10 in a form-fitting manner. In addition, the corresponding preferred component arrangement can be produced with reduced effort without air inclusions, since additional work steps to avoid air inclusions can be omitted and, moreover, an advantageous and thorough lamination, ie a favorable bond strength between the first rubber component 14 and the second rubber component 20, can be obtained more easily.

Those skilled in the art will understand that in order to obtain a corresponding preferred component arrangement 18 as shown in 5 is obtained, it is not necessarily necessary that the layer of the vulcanizable rubber mixture 16 is formed in the meantime in a separate step. At least if the second rubber component 20 has sufficient rigidity, it is also possible to place the second rubber component 20 directly onto a component arrangement 18, as shown, for example, in 2 or 3 is obtained, and the vulcanizable rubber mixture is indirectly formed by gently pressing the two rubber components together.

In the examples shown the 2 to 5 The vulcanizable rubber mixture each has a Mooney viscosity ML (1 + 3 / 100 ° C) according to DIN53523-2-1991 of less than 40 MU, whereas in the first rubber component 14 and in the second rubber component 20 each has a component rubber mixture with a Mooney viscosity of more than 65 MU is used. In the examples of 2 to 5 the volume of the vulcanizable rubber mixture 16 corresponds to approximately four times the volume of the electronic component 10. The vulcanizable rubber mixture 16 can, for example, comprise solution-polymerized styrene-butadiene rubber and preferably also contains 30 phr of a liquid polybutadiene polymer whose weight-average molecular weight Mw is less than 30,000 g /mol is. In addition, the vulcanizable rubber mixture can preferably contain, for example, 80 phr of fillers, with the examples shown each containing more than 15 phr of a carbon black.

6 shows a not yet vulcanized rubber product 12, into which the electronic component 10 was introduced using a method according to the invention. The rubber product is a pneumatic vehicle tire blank, which can be converted into a pneumatic vehicle tire by means of vulcanization. For reasons of clarity, the side wall element is hidden here. The electronic component 10 is arranged in the area of the tire sidewall on the tire carcass, which comprises a large number of rubberized reinforcements and functions as the first rubber component 14 in the example shown. In the example shown, a circumferential reinforcing strip acts as the second rubber component 20, which is arranged slightly further out in the radial direction than the inner tire bead and covers the electronic component 10. The dashed area indicates that the electronic component 10 is positively surrounded by a vulcanizable rubber mixture 16 as a result of the method according to the invention.

Reference symbol list

10

Electronic component

12

Rubber product

14

First rubber component

16

Vulcanizable rubber compound

18

Component arrangement

20

Second rubber component

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 3620312 A1 [0002]
• DE 102018220562 A1 [0002]
• US 2006164250 A1 [0008, 0031]
• US 9884462 B2 [0009, 0050]
• US 6613609 B1 [0018]
• EP 1855897 B1 [0018]
• EP 3632666 B1 [0018]

Non-patent literature cited

• DIN 53523-2-1991 [0022]

Claims (10)

Method for introducing electronic components (10) into a rubber product (12), comprising the method steps: a) producing or providing an electronic component (10), b) producing or providing a first rubber component (14) of the rubber product (12), as well as one of the process steps: c1) placing the electronic component (10) on the first rubber component (14) and covering the placed electronic component (10) with a vulcanizable rubber mixture (16), or c2) encasing the electronic component (10) with a vulcanizable rubber mixture (16) and placing the encased electronic component (10) on the first rubber component (14), to obtain a component arrangement (18) in which the electronic component (10) is essentially completely surrounded by the first rubber component (14) and by the vulcanizable rubber mixture (16), wherein the vulcanizable rubber mixture (16) has a Mooney viscosity ML (1+3 / 100 ° C) according to DIN 53523-2-1991 of 50 MU or less. Procedure according to Claim 1 , wherein the covering of the applied electronic component (10) with the vulcanizable rubber mixture (16) in method step c1) is carried out in such a way that, apart from the contact surface on the first rubber component (14), the electronic component (10) is essentially completely form-fitting from the vulcanizable Rubber mixture 616) is surrounded. Procedure according to one of the Claims 1 or 2 , wherein the encasing of the electronic component (10) with the vulcanizable rubber mixture (16) in method step c2) takes place in such a way that the electronic component (10) is essentially completely positively surrounded by the vulcanizable rubber mixture (16). Procedure according to one of the Claims 1 until 3 , wherein the encasing of the electronic component (10) with the vulcanizable rubber mixture (16) in process step c2) takes place in a separate form, with a prefabricated encased electronic component (10) with predetermined dimensions being obtained as an intermediate product. Procedure according to one of the Claims 1 until 4 , additionally comprising one or both of the method steps: d1) molding the vulcanizable rubber mixture (16) in the component arrangement (18), and / or d2) covering the component arrangement (18) with a second rubber component (20), the covering being carried out in this way, that the electronic component is arranged between the first rubber component (14) and the second rubber component (20). Procedure according to one of the Claims 1 until 5 , wherein the vulcanizable rubber mixture (16) is used in process step c1) or c2) to cover or encase the electronic component (10) in a volume in the range from 1.0*V _EK to 15.0*V _EK , where V _EK is the volume of the electronic component (10). Procedure according to one of the Claims 1 until 6 , wherein the vulcanizable rubber mixture (16) has a Mooney viscosity ML (1+3 / 100 ° C) according to DIN 53523-2-1991 of 45 MU or less. Procedure according to one of the Claims 1 until 7 , wherein the vulcanizable rubber mixture (16) comprises one or more polymers, the polymer being selected from the group consisting of polymers with a weight-average molecular weight Mw, measured by GPC, of 50,000 g/mol or less, the combined mass fraction of the polymers being of the vulcanizable rubber mixture is preferably in the range from 1 to 50 phr, based on the mass of the vulcanizable rubber mixture (16). Procedure according to one of the Claims 1 until 8th , wherein the vulcanizable rubber mixture (16) comprises one or more carbon blacks in a combined mass fraction in the range of 5 phr. Method for producing a vulcanized rubber product (12) with an electronic component (10), comprising the method steps of the method for introducing electronic components (10) into a rubber product (12) according to one of Claims 1 until 9 , as well as the method step: e) vulcanizing the component arrangement (18) to obtain a vulcanized component arrangement, the vulcanization being carried out in such a way that the vulcanized rubber mixture in the vulcanized component arrangement is cohesively connected to the vulcanized first rubber component (14).

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