Punch for closing holes, especially in sheet metal or plastic parts

Abstract

A die-cut part (10) for closing holes (100), particularly in sheet metal or plastic parts (101), wherein the die-cut part (10) consists of at least one carrier layer (102) with a top (103) and a bottom (104) and at least one adhesive layer (105) applied to the bottom (104) of the carrier layer (102) and is designed such that it has a projection (107) formed as an edge section (106) to the hole (100) to be closed, as well as a central section (108) with a geometry corresponding to the hole (100) to be closed, wherein the central section (108) of the die-cut part (10) has a weakening (109), makes it possible to forego a complex unmasking of the masking areas covered with such a die-cut part.

Description

[0001] The present invention relates to a stamped part for closing holes, particularly in sheet metal or plastic parts, wherein the stamped part consists of at least one carrier layer with a top and a bottom and at least one adhesive layer applied to the bottom of the carrier layer and is designed such that it has a projection designed as an edge section towards the hole to be closed and a central section with a geometry corresponding to the hole to be closed.

[0002] Furthermore, the invention relates to the use of such a stamped part for closing a hole in a sheet metal or plastic part, particularly in the automotive industry.

[0003] When manufacturing more complex structures from metal sheets and / or plastics, it is structurally unavoidable that holes must be cut into the sheets or plastics to access cavities behind them, whether for painting or welding.

[0004] These holes are usually no longer needed after the desired process is complete, and are often even a nuisance because air, humidity, or water can penetrate the structure through them, potentially leading to oxidation (rust), for example. A simple solution to avoid these problems is to seal the holes after use.

[0005] Especially in the production of modern vehicles such as watercraft, land vehicles (trucks, automobiles, etc.), aircraft, spacecraft, and combinations thereof, for example, amphibious vehicles, it is unavoidable that holes of varying sizes are required in many individual parts made of sheet metal or plastics during assembly. The diameters of these holes typically range from 5 to 50 mm. Many of these holes must later be sealed airtight and, in particular, watertight to prevent corrosion.

[0006] Furthermore, the holes need to be sealed to improve the sound insulation of the passenger interior.

[0007] The problems underlying the invention and their solution are described below using the example of an automobile body. This does not expressly limit the invention to this application. This application is part of the technical field in which the invention is particularly advantageous. From this point forward, whenever the use in a car body is mentioned, those skilled in the art will understand that all other possible applications outside of a car body are also included.

[0008] In automotive manufacturing, holes must be drilled or punched at various locations in the body. This typically occurs during the stamping and forming process of the individual sheet metal or aluminum parts. Holes can also be drilled into plastic components. Subsequently, the individual metal parts are joined together using various joining processes, resulting in the body shell. The holes, openings, or penetrations within this shell serve various purposes, including paint drain holes (for example, for cathodic dip coating), wax injection holes, wax drainage holes, holes for later screw connections during assembly, or for cable routing. Many of these holes must be sealed after the cathodic dip coating has dried or after the final clear coat application. In the latter case, the sealing takes place during the assembly process.

[0009] A hole closure may be necessary and / or desirable for various reasons, for example: - Protection from moisture - Avoidance of acoustic problems - Corrosion protection

[0010] Furthermore, after painting, a foam-like structural component is routinely injected into the body cavities of a car, contributing to an improvement in the vehicle's NVH (Noise, Vibration, Harshness) characteristics. It has long been known that acoustic foams are introduced into the body shell of vehicles to improve the NVH properties and reduce unwanted noise. To prevent the foam-like structural component from escaping during the injection process, a sufficiently robust plug that can withstand the injected foam is required.

[0011] German patent DE 102017217083 A1 discloses a sound-absorbing component for installation in a motor vehicle, a method for manufacturing a soundproofed body, and a motor vehicle, in particular a passenger car. The patent provides a sound-absorbing component for installation in a motor vehicle. This component comprises a sound-absorbing element, in particular a foam element, for essentially planar contact with at least one area of ​​a motor vehicle body, in particular a bulkhead, for the purpose of reducing sound transmission in a passenger compartment. Furthermore, the sound-absorbing component has at least one plug connected to the sound-absorbing element, with a plug for insertion into an opening of a body component or body component assembly. This serves to create a force-fit and / or form-fit connection between the sound-absorbing component and a material of the body component or body component assembly that forms the opening.

[0012] DE 102017201790 A1 discloses a sealing arrangement for foaming a body part of a motor vehicle having at least one cavity and openings with elastic plugs, wherein the elastic plugs correlate with the openings of the body part and are connected to each other by means of a connecting element.

[0013] Document DE 102019133868 B3 describes a filling plug for introducing foam into a cavity, particularly in a vehicle body, by means of an injection nozzle which has an injection opening, and comprises a plug body which has an inlet opening for inserting the injection nozzle into the filling plug, and a cover which has outlet openings for introducing foam into the cavity by means of the injection nozzle and is designed to cover the injection opening during the introduction of the foam.

[0014] Mounting openings are sealed against foam leakage with masking tape in a process-reliable manner; however, as a disadvantage, individual mounting materials, such as Christmas tree clips, screws or clips, can then be difficult to push through the masking tape during subsequent assembly.

[0015] The object of the present invention is therefore to provide a die-cut blank that securely and reliably seals body cavities, thus ensuring that, on the one hand, the mounting openings are protected against foam leakage and, on the other hand, allowing individual mounting materials to be easily inserted into the body cavities during subsequent assembly. It is also an object of the invention to provide a die-cut blank that can remain permanently on the hole to be sealed, thus eliminating the need for unmasking.

[0016] This problem is solved by a stamped part as described in the main claim. The dependent claims relate to advantageous further developments of the invention.

[0017] The invention then relates to a stamped part of the type mentioned at the outset, the central section of which has a weakening.

[0018] With such a die-cut plug, a hole can be precisely sealed, thus preventing foam from leaking out. Because the central section has a weakened area, mounting materials can still be inserted into these body cavities at any time without having to remove the die-cut plug. This weakening ensures that mounting materials, such as tree clips, screws, or clips, can be easily pushed through the die-cut plug. The previously necessary, time-consuming removal of masking tape is no longer required. The die-cut plugs can remain in place over the hole.

[0019] It is possible that the entire die-cut part has a weakening. However, it is particularly advantageous if the edge area of ​​the die-cut part has no weakening, so that it adheres to the substrate securely and without damage when pierced.

[0020] Preferably, the weakening is designed as an indentation pattern. More preferably, the indentation pattern is symmetrical and / or consists of triangles or quadrilaterals, in particular rhombuses or squares. In a preferred embodiment, the indentation pattern is formed at least substantially at an angle to the insertion of the mounting material. Thus, for a straight mounting material, the indentation pattern originates at least substantially at a 90° angle from the surface of the die-cut part, and for a conical mounting material, the angle is less than 90°. This ensures that the weakening tears in a controlled manner, the hole remains substantially sealed, and the edge section remains undamaged.

[0021] Such a die-cut piece is easy to apply. By adapting the central section to the hole geometry, especially the size and shape of the hole, the hole is closed precisely.

[0022] Preferably, the central section is arranged concentrically on the die-cutting piece. This ensures that a uniform overhang of the die-cutting piece, forming an edge section, is present at all areas of the hole contour.

[0023] The contour of the hole must be taken into account. Often this is a circle. In such cases, the central section is also a circle, and it is easy to provide the overhang, which forms the edge section, with the same geometry and to arrange the central and edge sections concentrically. But a concentric arrangement is also possible with other geometries such as ellipses, ovals, squares, rectangles, or triangles.

[0024] The projection from the outer contour of the edge section to the outer contour of the central section, and thus of the hole, is preferably between 1 and 20 mm, particularly preferably between 4.5 and 10 mm. With such dimensions, a secure closure of the hole is possible.

[0025] A particularly preferred embodiment is characterized in that the weakening extends only over a part of the height of the stamped part, starting from the top of the carrier layer.

[0026] By extending the weakening only over a portion of the die-cut's height, a smooth, unweakened underside is ensured. This offers the advantage of preventing foams or other materials from leaking out or penetrating the die-cut, thus maintaining its stability. Because the weakening originates from the top, mounting materials can still be easily pushed through the die-cut. Preferably, the weakening extends over 10 to 90%, and more preferably over 40 to 60%, of the die-cut's height.

[0027] A particularly advantageous embodiment of the invention is characterized in that the weakening is formed as a structure burned in by means of a laser.

[0028] The laser-etched structure results in a microstructuring of the stamped part's surface. This microstructuring is performed with very high precision. Advantageously, a laser beam creates a very fine structure on the stamped part's surface, roughening and / or weakening it. Both micrometer-precise application of individual structures and full-surface structuring are possible. The laser beam removes material from a predefined area, thus altering the surface's functionality. The material largely vaporizes directly, preventing melting.

[0029] In a further advantageous embodiment, the weakening is achieved through embossing. The embossing reshapes the surface of the stamped part. This is accomplished using pressure, temperature, and time. The embossing is negative, creating a depression. The depression can be partial or full-surface and results in the desired weakening. Preferably, the embossing is a flat embossing, a relief embossing, a textured embossing, or a micro-embossing.

[0030] It is also possible to combine weakening by using a laser with simultaneous embossing.

[0031] Another advantageous embodiment of the invention is characterized in that the weakening is formed as at least one indentation, in particular a slit-shaped indentation.

[0032] The indentation is preferably a depression extending from the surface towards the underside of the die-cut part. Preferably, the weakening is formed as an indentation pattern. More preferably, the indentation pattern is symmetrical and / or consists of triangles or quadrilaterals, in particular rhombuses or squares. In a preferred embodiment, the indentation pattern is formed at least substantially at an angle to the insertion of the mounting material. Thus, for a straight mounting material, the indentation pattern originates at least substantially at a 90° angle from the surface of the die-cut part, and for a conical mounting material, the angle is less than 90°. This ensures that the weakening tears in a controlled manner, the hole remains substantially closed, and the edge section remains undamaged.

[0033] The support layer can consist of any polymer, either alone or in mixture. Suitable polymers are olefinic polymers such as homo- or copolymers of olefins like ethylene, propylene, or butylene (the term copolymer here is to be understood as including terpolymers), polypropylene homopolymers, or polypropylene copolymers, including block (impact) and random polymers.

[0034] Other polymers can be selected from the group of polyesters, such as polyethylene terephthalate (PET), polyamides, polyurethanes, polyoxymethylene, polyvinyl chloride (PVC), polyethylene naphthalate (PEN), ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polycarbonate (PC), polyamide (PA), polyethersulfone (PES), polyimide (PI), polyarylene sulfides and / or polyarylene oxides.

[0035] The carrier layer can preferably consist of polyester, polyurethane or PVC, with polyester, in particular polyethylene terephthalate (PET), being especially preferred.

[0036] According to a preferred embodiment, the thickness of the carrier layer, particularly when it is formed from a single film layer, is between 25 and 3,500 µm, preferably between 25 and 200 µm.

[0037] Furthermore, preferably the carrier layer, especially if it is formed from a single film layer, has a basis weight between 10 and 200 g / m². 2 , preferably between 15 and 100 g / m² 2 For example, a basis weight of 70 g / m² 2 (for a 50 µm PET film layer) or 16 g / m² 2 (for a 25 µm PET film layer).

[0038] The carrier layer can consist of a single layer or comprise one or more additional layers. These can be, for example, a foil layer, a metallic layer, a layer made of glass fabric or woven glass, a layer made of flame-retardant foam, or a functional layer. The order of the layers is arbitrary. The adhesive layer, which serves to attach the die-cut part to the sheet metal or plastic component, is applied to the underside of the bottommost layer.

[0039] The carrier layer can optionally have a basis weight of at least 1.0 kg / m². 2 It exhibits these properties and is then referred to as heavy foil. According to a preferred embodiment, this heavy foil has a basis weight between 1.0 and 6 kg / m². 2 , preferably between 1.5 and 3.9 kg / m² 2 between 1.5 and 2.5 kg / m² 2 on.

[0040] The heavy film can consist of any polymer, either alone or in mixtures. Suitable polymers include olefinic polymers such as homopolymers or copolymers of olefins like ethylene, propylene, or butylene (the term copolymer here is to be understood as including terpolymers), polypropylene homopolymers, or polypropylene copolymers, including block (impact) and random polymers. Other polymers can be selected from the polyester group, such as, in particular, polyethylene terephthalate (PET), polyamides, polyurethanes, polyoxymethylene, polyvinyl chloride (PVC), polyethylene naphthalate (PEN), ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polycarbonate (PC), polyamide (PA), polyethersulfone (PES), polyimide (PI), polyarylene sulfides, and / or polyarylene oxides. These polymers, alone or in mixtures, are suitable for forming the heavy film.

[0041] Preferably, the heavy foil is filled with mineral fillers, in particular limestone flour or calcite (CaCO3) and barite (BaSO4). Talc, slate flour, graphite, mica, or asbestos (the latter less commonly used today) can also be used as fillers.

[0042] The proportion of fillers is particularly 30 to 90 wt.%, preferably 40 to 70 wt.%, based on the total weight of the film. Expressed as a volume percent, the proportion is preferably 30 to 60 vol.%, more preferably 45 to 55 vol.% based on the total volume of the film.

[0043] The heavy foil may additionally contain oil for swelling and improved absorption of the fillers. The oil content can range from 8 wt.% to 30 wt.%, preferably 10 wt.% to 25 wt.%, based on the total weight of the foil.

[0044] The heavy film is preferably a polyolefin film, especially one filled with minerals, a polyethylene and EVA film, especially one filled with minerals, or an elastomer-modified bitumen film. The heavy film more preferably contains oil.

[0045] Another layer can be a film layer. According to a preferred embodiment, the film layer consists of polyolefins, which include polyethylene, polypropylene, and polyethylene and polypropylene homo- and copolymers. The copolymers can be statistically distributed or block copolymers with comonomers such as ethylene or propylene, or other α-olefins. This film can also be a blend with other polyolefins, in particular polyethylene or ethylene copolymers with comonomers such as 1-butene, 1-hexene, 1-octene (depending on the proportion and manufacturing process, then called LLDPE, VLDPE, ULDPE, or metallocene-PE), but also ethylene-styrene copolymers, ethylene with polar comonomers such as acrylic acid, alkyl acrylates, methalkyl acrylates, or vinyl acetate, or grafted copolymers, for example, with maleic anhydride.

[0046] The thickness of this foil layer is preferably between 25 and 200 µm, particularly preferably between 40 and 140 µm, and most preferably between 50 and 90 µm.

[0047] A metallic layer preferably has a thickness of 10 to 40 µm, in particular 12 to 20 µm, and more preferably 18 µm. Optionally, this layer may also have an embossed pattern.

[0048] Suitable metals include silver, copper, gold, platinum, aluminum and aluminum compounds, tin, nichrome, stainless steel, titanium, and metal oxides such as cadmium oxides, tin oxides, zinc oxides, and magnesium oxides. Aluminum is particularly preferred. This list is not exhaustive; a person skilled in the art may choose other metal layers not explicitly mentioned here without departing from the inventive concept. Preferably, the metal is a rolled foil, especially aluminum foil.

[0049] In a further advantageous embodiment according to the invention, layers of metal oxide (MeOx layers) can be used as the metallic layer. Advantageous metal oxide layers consist, for example, of silicon dioxide (SiO2), titanium dioxide (TiO2), or zinc-tin oxide (ZnSnO), or they comprise one or more of these metal oxides.

[0050] A layer of glass fabric or woven material advantageously has the following properties: The basis weight is between 30 and 200 g / m². 2 , especially between 0 and 120 g / m² 2 , preferably between 70 and 100 g / m² 2 , and furthermore, in particular between 80 and 90 g / m² 2 The number of threads in the warp and / or the number of threads in the weft is 3 to 50 threads / cm. According to a further advantageous embodiment of the invention, the number of threads in the warp is 5 to 10 / cm, preferably 7 / cm, and / or the number of threads in the weft is 4 to 10 / cm, preferably 5 / cm.

[0051] The yarn weight of the longitudinal and transverse yarns is preferably between 500 and 1000 dtex, more preferably between 600 and 800 dtex, and particularly preferably 680 dtex.

[0052] The weft density is defined as the number of weft threads per centimeter multiplied by the thread weight of the weft threads in dtex. The unit is dtex / cm. The warp density is defined as the number of warp threads per centimeter multiplied by the thread weight of the warp threads in dtex. The unit is also dtex / cm. According to a further advantageous embodiment of the invention, the warp density and / or the weft density is greater than 2000 dtex / cm. Preferably, the warp density is between 4000 and 5000 dtex / cm and / or the weft density is between 3000 and 4000 dtex / cm.

[0053] In glass fabric, the threads are woven in a plain weave. Other weave types include satin weave (also known as sateen, which comes in regular and irregular forms) and twill weave. Fabrics in twill weave (for example, a "2 over 1 twill") create a so-called twill rib, which runs diagonally to the machine direction.

[0054] A lay-up is a sheet-like structure consisting of one or more layers of parallel, elongated threads. The threads are typically fixed at their intersections. This fixing is achieved either through fabric interlocking or mechanically through friction and / or interlocking. The following types of lay-ups exist: • monoaxial or unidirectional, which are created by fixing a set of parallel threads • biaxial, in which two sets of parallel threads are fixed in the direction of two axes • Multiaxial: several sets of parallel threads are fixed in the direction of different axes.

[0055] The yarn layers in multi-layered fabrics can all have different orientations and can also consist of different yarn densities and yarn finenesses. Single-layer fabrics are preferred according to the invention.

[0056] Functional layers, which can be arranged between the other layers, include, for example, adhesion promoters to improve bond strength. Preferably, a further adhesive layer in the form of a laminating adhesive is used, with a surface application weight of 5 to 50 g / m². 2 , especially from 7 to 20 g / m² 2 . Pressure-sensitive adhesives are particularly suitable as laminating adhesives.

[0057] However, it is also possible to join the layers together under pressure through lamination.

[0058] A functional layer can have a barrier effect against migratory substances such as plasticizers, especially oils, which could diffuse from other layers into the adhesive layer. Preferably, the functional layer also has a barrier effect against migratory substances such as adhesive resins, which conversely could diffuse from the adhesive into the substrate layers. Preferably, the barrier effect of the functional layer is realized on both sides. Furthermore, such a layer can also have adhesion-promoting properties.

[0059] The polymers of the functional layer can be selected from the group of polyesters, such as polyethylene terephthalate (PET), polyamides, polyurethanes, polyoxymethylene, polyvinyl chloride (PVC), polyethylene naphthalate (PEN), ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polycarbonate (PC), polyamide (PA), polyethersulfone (PES), polyimide (PI), polyarylene sulfides, and / or polyarylene oxides, either alone or in mixtures. More preferably, the functional layer consists of one of the aforementioned polymers. Particularly preferably, the functional layer consists of polyamide. The advantage of polyamide is that a polyamide film exhibits good barrier properties against oil.

[0060] The thickness of the functional layer is preferably chosen to be as small as possible, since the corresponding functional polymers are usually more expensive. Relative to the total thickness of the substrate layer, the functional layer preferably has a thickness of 5 to 80%, and more preferably 10 to 50%. The thickness of the functional layer is chosen so that it does not become zero within the technically induced thickness variation. Therefore, it is never completely absent in any area.

[0061] The adhesive layer is preferably a layer consisting of an adhesive compound, preferably with a basis weight of 10 to 2,000 g / m². 2 , preferably 25 to 500 g / m² 2 and / or a thickness of 10 to 2,000 µm, preferably 25 to 500 µm.

[0062] In a preferred embodiment, the adhesive layer applied to the substrate is a pressure-sensitive adhesive, meaning it forms a permanent bond with almost all substrates even under relatively light pressure and can be removed from the substrate essentially without leaving any residue after use. A pressure-sensitive adhesive remains permanently tacky at room temperature, exhibiting a sufficiently low viscosity and high initial tack to wet the surface of the substrate even with minimal pressure. The adhesive's bonding ability is based on its adhesive properties, while its removability is due to its cohesive properties.

[0063] All known adhesive systems can be used. In addition to natural or synthetic rubber-based adhesives, silicone adhesives and polyacrylate adhesives, preferably a low-molecular-weight acrylate hot melt adhesive, are particularly suitable.

[0064] The adhesive is preferably a non-thermoplastic elastomer-based adhesive, the elastomer of which consists of at least 40 wt.%, preferably at least 50 wt.%, of non-thermoplastic elastomer. In a preferred embodiment, the elastomer contained in the adhesive consists of at least 90 wt.%, and particularly 100 wt.%, i.e., exclusively, of non-thermoplastic elastomer. To improve processability, thermoplastic elastomers can thus be added to the non-thermoplastic elastomers in a weight fraction of typically 10 to 50 wt.%, based on the total elastomer content of the adhesive. By way of example, the particularly compatible styrene-isoprene-styrene (SIS) and styrene-butadiene-styrene (SBS) types should be mentioned here.Advantageously, the non-thermoplastic elastomer is selected from the group of natural rubbers or synthetic rubbers, or it consists of any blend of natural rubbers and / or synthetic rubbers.

[0065] Natural rubber(s) can generally be selected from all available grades, such as crepe, RSS, ADS, TSR, or CV types, depending on the required purity and viscosity level. Synthetic rubber(s) can be selected, in particular, from the group of statistically copolymerized styrene-butadiene rubbers (SBR), butadiene rubbers (BR), acrylonitrile butadiene rubbers (NBR), synthetic polyisoprenes (IR), butyl rubbers (IIR), halogenated butyl rubbers (XIIR), acrylate rubbers (ACM), ethylene-vinyl acetate copolymers (EVA), and polyurethanes and / or their blends.

[0066] In the production of adhesives, tackifier resin is frequently used, particularly to achieve suitable adhesion, for example, in self-adhesive compounds based on natural rubber. The term "tackifier resin" refers to a resin-based substance that increases stickiness. The typical amount of tackifier resin used depends primarily on the type of elastomer employed. With certain types of elastomers, such as acrylate rubbers (ACM), tackifier resin is often omitted due to their inherent stickiness. Generally, however, a total of 30 to 160 phr of tackifier resin is used in the production of a self-adhesive compound according to the invention, preferably 50 to 130 phr, and more preferably 80 to 120 phr. Within these ranges, particularly good adhesion and cohesion values ​​can often be achieved simultaneously.The information given in the present application in phr (English, “parts per hundred rubber”) means parts by weight of the component in question in relation to the total proportion of elastomer contained in the self-adhesive compound.

[0067] All known adhesive resins described in the literature can be used. These include, in particular, rosin resins, their disproportionate, hydrogenated, polymerized, and esterified derivatives and salts, as well as aliphatic and aromatic hydrocarbon resins, polyterpene resins, and terpene phenolic resins. Any combination of these and other resins can be used to tailor the properties of the resulting adhesive to the desired characteristics. Reference is expressly made to the presentation of the current state of knowledge in the "Handbook of Pressure Sensitive Adhesive Technology" by Donatas Satas (van Nostrand, 1989).

[0068] Suitable adhesive resins include, in particular, hydrogenated and non-hydrogenated hydrocarbon resins and polyterpene resins. Hydrogenated polymers of dicyclopentadiene (e.g., Escorez 5300 series; Exxon Chemicals) and hydrogenated polymers of preferably Cs and Cg aromatics (e.g., Regalite and Regalrez series; Eastman Inc. or Arkon P series; Arakawa) are especially suitable. These can be produced by hydrogenation of polymers from pure aromatic streams or by hydrogenation of polymers based on mixtures of different aromatics. Partially hydrogenated polymers of Cs and Cg aromatics (e.g., Regalite and Regalrez series; Eastman Inc.) are also suitable.or Arkon M; Arakawa), hydrogenated polyterpene resins (for example, Clearon M; Yasuhara), hydrogenated Cs / Cg polymers (for example, ECR-373; Exxon Chemicals), and aromatic-modified selectively hydrogenated dicyclopentadiene derivatives (for example, Escorez 5600 series; Exxon Chemicals). The aforementioned adhesive resins can be used alone or in mixtures.

[0069] Hydrogenated hydrocarbon resins are particularly suitable as a blending component for crosslinkable styrene block copolymers, as described for example in EP 0 447 855 A1, US 4,133,731 A and US 4,820,746 A, because the absence of double bonds prevents crosslinking from being disrupted.

[0070] Furthermore, non-hydrogenated resins can also be used if crosslinking promoters such as multifunctional acrylates are employed. Polyterpene resins based on α-pinene (Piccolyte A-series from Hercules, Dercolyte A-series from DRT) are particularly preferred under these conditions, as they ensure not only high cohesion but also very high adhesion, even at high temperatures. However, other non-hydrogenated hydrocarbon resins, non-hydrogenated analogs of the hydrogenated resins described above, can also be used. The preferred use of crosslinking promoters also allows the use of rosin-based resins. Due to their low adhesion at elevated temperatures, these are mainly used as blending components.

[0071] To stabilize the adhesive mass, primary antioxidants (antioxidants) such as sterically hindered phenols, secondary antioxidants such as phosphites or thioethers and / or C radical scavengers are usually added.

[0072] All plasticizing substances known from adhesive tape technology can be used as plasticizers. These include, among others, paraffinic and naphthenic oils, (functionalized) oligomers such as oligobutadienes and -isoprenes, liquid nitrile rubbers, liquid terpene resins, vegetable and animal oils and fats, phthalates, and functionalized acrylates.

[0073] For the purpose of thermally induced chemical crosslinking, i.e., thermal crosslinking, all previously known thermally activatable chemical crosslinkers, i.e., thermal crosslinkers, such as, in particular, accelerated sulfur or sulfur donor systems, isocyanate systems, reactive melamine, formaldehyde, and (optionally halogenated) phenol-formaldehyde resins, or reactive phenol resin or diisocyanate crosslinking systems with the corresponding activators, epoxidized polyester and acrylate resins, and combinations thereof, can be used in the process according to the invention. In a particularly preferred embodiment of the thermal crosslinking of the self-adhesive compound, the thermal crosslinker forms a network with the non-thermoplastic elastomer; i.e., the network results from a reaction of the thermal crosslinker with the non-thermoplastic elastomer.In an alternative embodiment of the thermal crosslinking of the self-adhesive compound, the thermal crosslinker forms a network with the thermoplastic elastomer contained in the self-adhesive compound; that is, the network results from a reaction of the thermal crosslinker with the thermoplastic elastomer. In another embodiment of the thermal crosslinking of the self-adhesive compound, the thermal crosslinker forms a network of itself; that is, the network results from a reaction of the thermal crosslinker with itself. If a non-thermoplastic elastomer or a thermoplastic elastomer is to form a network with a thermal crosslinker, the elastomer must be thermally crosslinkable. This means that it must possess functional groups that react with a suitable thermal crosslinker at an appropriate temperature.Typical functional groups include, in particular, C=C double bonds, epoxide groups, carboxylic acid groups, carboxylic anhydride groups, hydroxy groups, amino groups, or mixtures thereof.

[0074] According to the invention, the thermal crosslinkers are preferably activated at temperatures of 100°C to 180°C, more preferably at temperatures of 110°C to 160°C and most preferably at temperatures of 120°C to 140°C.

[0075] A typical size and shape for the die-cut piece, which can be used to close many of the smaller holes, is a (circular) disc with a diameter (cover part) of 10 to 60 mm, in particular 30 to 40 mm.

[0076] Another advantageous embodiment of the invention is characterized in that the projection is between 1 and 20 mm, preferably between 4.5 and 10 mm. With such dimensions, a secure closure of the hole is possible. The projection is also selected such that the die-cut piece adheres securely to the adhesive material. This is particularly necessary when mounting materials penetrate the central section.

[0077] According to a further aspect of the present invention, it comprises the use of a die, as described above, for closing a hole in a sheet metal or plastic part, particularly in the automotive industry. The dies according to the invention can be used in a wide variety of fields where closing holes in parts of a certain thickness is required. The dies are particularly suitable for closing sheet metal or plastic parts, such as those used in the automotive industry. The need to create holes in sheet metal and plastic parts and then close them again has already been explained in detail above.

[0078] In the following, further suitable and / or advantageous features and developments will be explained in more detail using a particularly preferred embodiment of the stamped part for permanently closing holes, especially in sheet metal or plastic parts of automobile bodies, with reference to the attached drawing, without being intended to be restrictive in any way.

[0079] It shows Fig. 1 a schematic representation of an embodiment of a stamped part according to the invention in a top view and Fig. 2 a schematic representation of the in Fig. 1. The die-cut shown is applied to a hole in a side view.

[0080] The die shown in the figures is an example designed for sealing holes, particularly in sheet metal or plastic parts. The die shown represents a preferred embodiment. The features and further developments of the die according to the invention described below represent preferred embodiments, either individually or in combination. Each feature functions independently and, in particular when combined, ensures that the preferred weakening in the central section of the die protects the mounting opening against foam leakage while still allowing mounting materials to be easily inserted into the body cavities.

[0081] Fig. Figure 1 schematically shows the stamped part 10 according to the invention. In the top view of the Fig. Figure 1 shows the upper surface 103 of the die-cutting piece, which is designed as a support layer 102. The die-cutting piece 10 has a central section 108 and a projection 107 designed as an edge section 106. The central section 108 is provided with a weakening 109. This is shown in the Fig. 1 embodiment shown as slot-shaped indentations 111.

[0082] Fig. Figure 2 schematically shows a sheet metal or plastic part of a vehicle having a hole 100. The hole 100 is closed with a stamped part 10 according to the invention.

[0083] The die-cut part 10 consists of a carrier layer 102 with a top surface 103 and a bottom surface 104, and at least one adhesive layer 105 applied to the bottom surface 104 of the carrier layer 102. Fig. Figure 1 shows an example of a particularly preferred round geometry of the central section 108.

[0084] In Fig. 2 can be seen that the stamped part 10 is designed such that the central section 108 has a geometry corresponding to the hole to be closed and the protrusion 107, designed as an edge section 106, can be attached to the material surrounding the hole.

[0085] As in Fig. 1 and Fig. As shown in Figure 2, the central section 108 has a weakening 109. This weakening 109 extends only over a portion of the height H of the stamped part 10, starting from the top surface 103 of the carrier layer 102. The weakening is formed as several slit-shaped indentations. QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 102017217083 A1

[0011] DE 102017201790 A1

[0012] DE 102019133868 B3

[0013] EP 0 447 855 A1

[0069] US 4,133,731 A

[0069] US 4,820,746 A

[0069]

Claims

[1] Stamped blank (10) for closing holes (100) especially in sheet metal or in plastic parts (101), wherein the die-cutting element (10) consists of at least one carrier layer (102) with a top (103) and a bottom (104) and at least one adhesive layer (105) applied to the bottom (104) of the carrier layer (102) and is designed such that it has a projection (107) designed as an edge section (106) to the hole (100) to be closed as well as a central section (108) with a geometry corresponding to the hole (100) to be closed, characterized by , that the central section (108) of the die (10) exhibits a weakening (109). [2] Stamping die (10) according to claim 1, characterized by , that the weakening (109) extends only over part of the height (H) of the die (10) starting from the top (103) of the carrier layer (102). [3] Stamping die (10) according to one of claims 1 or 2, characterized by , that the weakening (109) is formed as a structure burned in by means of a laser. [4] Stamping die (10) according to one of claims 1 or 2, characterized by , that the weakening (109) is formed as an imprint. [5] Stanzling (10) according to at least one of the previous claims, characterized by , that the weakening (109) is formed as at least one indentation (111), in particular a slit-shaped indentation (111). [6] Stanzling (10) according to at least one of the previous claims, characterized by , that the at least one carrier layer (102) consists of polyester, in particular of polyethylene terephthalate (PET). [7] Stanzling (10) according to at least one of the previous claims, characterized by , that the adhesive mass of the adhesive layer (105) is an adhesive mass. [8] Stanzling (10) according to at least one of the previous claims, characterized by, that the overhang (107) is between 1 and 20 mm, preferably between 4.5 and 10 mm. [9] Use of a stamped part (10) according to any one of claims 1 to 8 for closing a hole (100) in a sheet metal or plastic part (101), particularly in the automotive industry.

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