Insulated passage system

Abstract

An insulated passage system in an electrically driven motor vehicle comprises a passage which connects a first region (9) to a second region (10), wherein the first region (9) is air-permeable towards a battery of the motor vehicle, and wherein the second region (10) is air-permeable towards a passenger compartment of the motor vehicle. The system also comprises an insulating element (2) which comprises an expanded material (3'), wherein the expanded material (3') closes the passage towards the first region (9), and wherein the expanded material (3') is a single-component, heat-hardened epoxy resin composition.

Description

[0001] SYSTEM OF AN INSULATED PASSAGE

[0002] The invention relates to an insulated passage system, and more particularly to an insulated passage system in an electrically powered motor vehicle.

[0003] In addition to the usual acoustic insulation, electrically powered vehicles also face the problem of protecting the interior in the event of a battery malfunction. If the battery of an electrically powered vehicle experiences thermal runaway, or overheats in an exothermic chemical reaction, toxic and extremely hot gases are released. These toxic and extremely hot gases must be kept away from the passenger compartment of the vehicle for a certain minimum period of time so that the vehicle's occupants can escape to safety in time.

[0004] It is therefore an object of the present invention to provide a device which makes it possible to keep thermally toxic hot gases, which arise during a thermal runaway of the battery of an electrically powered motor vehicle, away from the passenger compartment.

[0005] This object is achieved by a system for an insulated passageway in an electrically powered motor vehicle, the system comprising: a passageway connecting a first region to a second region, wherein the first region is permeable to air towards a battery of the motor vehicle and wherein the second region is permeable to air towards a passenger compartment of the motor vehicle; and an insulating element comprising an expanded material, wherein the expanded material closes the passageway towards the first region; wherein the expanded material is a foamed and at least partially cured epoxy resin composition. This solution has the advantage that materials already known in automotive construction can be used to meet this new application.Epoxy-based compositions expanded in this way under the influence of heat are often used to reinforce body sections. These materials exhibit very high mechanical strength in an expanded and cured state. Such materials are often referred to as "expanding reinforcer material," "reinforcer foam," "reinforcer material," or "expanding adhesives."

[0006] Thus, one advantage of the solution proposed here is that proven and well-known materials can be used to solve the problem posed at the beginning. For example, such materials do not need to be re-approved by automobile manufacturers, thus saving costs and effort.

[0007] The solution proposed here also offers the advantage of using an expandable material that enables simple and efficient insulation of a passageway. The insulation elements proposed here can be installed in the body in a non-expanded state and then expanded and cured in an oven during the paint coating process. This makes handling, installation, and planning of such insulation elements simple and cost-effective.

[0008] In the context of this invention, the terms "insulating element" or "insulation" or "insulated" encompass elements or structures or process steps for sealing and / or closing and / or insulating a passage. The various properties of such an insulating element can occur individually or in combination with one another. In one exemplary embodiment, the passage is channel-shaped.

[0009] In an exemplary embodiment, the passage is formed by side walls surrounding a cavity.

[0010] In an alternative embodiment, the passage is hole-shaped. In particular, the passage is formed by an opening in a wall.

[0011] In an exemplary embodiment, only expanded material is exposed from the insulation element to the first region.

[0012] Such an arrangement of expanded material offers the advantage that the cured epoxy resin composition forms an effective protective shield against the toxic and hot gases emitted by the continuous battery. Experiments have shown that many other materials cannot withstand such exposure for a sufficiently long time. Therefore, it is advantageous if only this resistant expanded material is exposed to the hot gas, and not other components of the insulation element (such as sections of a support or similar).

[0013] In an exemplary embodiment, the expanded material has a layer thickness, measured in a direction along a main passage axis of the passage, between 1 and 50 mm. This layer thickness is preferably between 2 and 30 mm, particularly preferably between 5 and 20 mm.

[0014] Experiments have shown that a certain layer thickness is necessary to withstand the stress of the hot gas for a sufficient period of time. In tests, a top layer of the cured epoxy resin composition was charred during exposure to the hot gas, but underlying layers of the cured epoxy resin composition remained intact. Therefore, a sufficiently thick layer must be provided to withstand the stress of the hot gas for a sufficient period of time.

[0015] In an exemplary embodiment, the expanded material prior to expansion, i.e., the expandable material, has a layer thickness, measured in a direction along a main passage axis of the passage, of between 1 and 10 mm. This layer thickness is preferably between 2 and 7 mm, particularly preferably between 3 and 6 mm.

[0016] In an exemplary embodiment, the insulating element also comprises a carrier.

[0017] The provision of a carrier offers the advantage that the expanded material can be positioned more easily and precisely in the vehicle before expansion.

[0018] In one exemplary embodiment, the carrier is designed as a film. In particular, the carrier is flexible. In another exemplary embodiment, the carrier can be made of metal.

[0019] In an alternative embodiment, the carrier is designed as a rigid carrier, wherein the carrier is made in particular of plastic.

[0020] In an exemplary further development, the carrier and expanded material were manufactured using a two-component injection molding process.

[0021] In an exemplary embodiment, the insulating element does not comprise a carrier.

[0022] This offers the advantage that the insulation element can be manufactured more cost-effectively, for example, through an extrusion process. In an exemplary embodiment, the insulation element is attached to a structure of the passageway using an adhesive film.

[0023] This has the advantage that the expandable material can be positioned in the passage area before expansion.

[0024] In another exemplary embodiment, the insulation element is attached to a structure of the passage by a pushpin.

[0025] This method also offers the advantage that the expandable material can be pre-fixed at a desired position in the passage area before expansion without a support.

[0026] In an exemplary embodiment, the system is in a motor vehicle without an internal combustion engine.

[0027] In an alternative embodiment, the system is in a motor vehicle with electric drive and with internal combustion engine (in particular in a hybrid vehicle).

[0028] In the context of this invention, the term "motor vehicle battery" refers to a battery used to supply an electric drive with energy. It expressly does not refer to a battery used to start an internal combustion engine.

[0029] Expanded material

[0030] In a used state, i.e., a system of insulated passages found in a finished automobile, the originally expandable material exists as an expanded material. However, certain properties of this expanded material can be better described based on a state before expansion. Therefore, in the following detailed description of this material, reference is made to the expanded material after expansion and to the expandable material before expansion.

[0031] In an exemplary embodiment, the expanded material has a volume between 50% and 1200% greater than before expansion. In a preferred development, the volume increases by between 100 and 1000%, preferably between 200 and 800%.

[0032] In an exemplary embodiment, the expanded material is a foamed and cured epoxy composition.

[0033] In an exemplary embodiment, the expanded material is obtained from a one-component thermosetting epoxy resin composition.

[0034] In an exemplary embodiment, the expanded material (3') was present before expansion as an expandable material (3) which contained the following composition:

[0035] One-component thermosetting epoxy resin composition comprising a) at least one epoxy resin A having on average more than one epoxy group per molecule; b) at least one latent hardener for epoxy resins; and c) at least one physical or chemical blowing agent BA.

[0036] In an exemplary embodiment, the proportion of epoxy resin A with an average of more than one epoxy group per molecule is 30-90 wt.%, 35-85 wt.%, 40-75 wt.%, more preferably 45-60 wt.%, based on the total weight of the thermosetting one-component epoxy resin composition. In an exemplary embodiment, epoxy resin A is a solid epoxy resin.

[0037] In an exemplary embodiment, the one-component thermosetting epoxy resin composition further comprises d) at least one toughener D.

[0038] In an exemplary embodiment, the toughener D is selected from the group consisting of terminally blocked polyurethane polymers D1, liquid rubbers D2 and core-shell polymers D3.

[0039] In an exemplary embodiment, the latent hardener is selected from dicyandiamide, guanamines, guanidines, aminoguanidines and derivatives thereof, substituted ureas, imidazoles and amine complexes, preferably dicyandiamide.

[0040] In an exemplary embodiment, the one-component thermosetting epoxy resin composition further comprises at least one filler F selected from the group consisting of calcium carbonate, calcium oxide, talc, glass fibers, and fumed silicas, preferably talc, glass fibers, and fumed silicas.

[0041] In an exemplary embodiment, the one-component thermosetting epoxy resin composition further comprises at least one flame-retardant component G. In particular, the flame-retardant component G is selected from the list consisting of ammonium phosphate, ammonium pyrophosphate, ammonium polyphosphate, melamine phosphate, magnesium sulfate, and boric acid, preferably ammonium polyphosphate. The ammonium polyphosphate preferably has a particle size of <100 pm, in particular 50 pm - 5 pm.

[0042] The total proportion of the flame-retardant component G is advantageously 3-50 wt.%, preferably 5-40 wt.%, 8-35 wt.%, based on the total weight of the epoxy resin composition.

[0043] It is further advantageous if the ammonium polyphosphate is an ammonium polyphosphate of the formula (NH4PO3)n with n of 200 - 2000, preferably 600 - 1500.

[0044] In an exemplary embodiment, the proportion of the blowing agent BA is 0.1-10 wt.%, preferably 0.5-5 wt.%, in particular 1-3 wt.%, based on the total weight of the epoxy resin composition.

[0045] The epoxy resin composition is a single-component system, meaning that the components of the epoxy resin composition, specifically the epoxy resin and the hardener, are present in a single component without curing at normal ambient or room temperature. It can therefore be handled in this form, whereas with two-component systems, the components can only be mixed immediately before application.

[0046] The curing of the one-component epoxy resin composition takes place by heating, typically at a temperature of more than 70°C, for example in the range of 100 to 220°C.

[0047] The prefix "poly" in terms like polyol or polyisocyanate means that the compound contains two or more of the groups mentioned. A polyisocyanate, for example, is a compound with two or more isocyanate groups.

[0048] The term "independently of one another" used below means that two or more identically designated substituents in the same molecule can, by definition, have the same or different meanings. The dashed lines in the formulas of this document represent the bond between the respective substituent and the corresponding residue of the molecule.

[0049] Room temperature here refers to a temperature of 23°C, unless otherwise stated.

[0050] The heat-curing, one-component epoxy resin composition contains at least one epoxy resin A with an average of more than one epoxy group per molecule. The epoxy group is preferably present as a glycidyl ether group.

[0051] The proportion of epoxy resin A with an average of more than one epoxy group per molecule is preferably 30-90 wt.%, 35-85 wt. , 40-75 wt.%, particularly preferably -45-60 wt.%, based on the total weight of the heat-curing one-component epoxy resin composition.

[0052] The epoxy resin A, with an average of more than one epoxy group per molecule, is preferably a liquid epoxy resin or a solid epoxy resin, particularly preferably a solid epoxy resin. The term "solid epoxy resin" is very familiar to those skilled in the art of epoxides and is used in contrast to "liquid epoxy resins." The glass transition temperature of solid resins is above room temperature, so they can be comminuted into free-flowing powders at room temperature. Preferably, more than 70 wt.%, particularly preferably more than 80 wt.%, more than 90 wt.%, more than 95 wt.%, more than 98 wt.% of the epoxy resin A is a solid epoxy resin.

[0053] Preferred epoxy resins have the formula (II) In this formula, the substituents R' and R" independently represent either H or CH3.

[0054] For solid epoxy resins, the index s has a value of > 1.5, in particular from 2 to 12.

[0055] Such solid epoxy resins are commercially available from companies such as Dow, Huntsman or Hexion.

[0056] Compounds of formula (II) with an index s of 1 to 1.5 are referred to by those skilled in the art as semi-solid epoxy resins. For the purposes of the present invention, they are also considered solid resins. However, preferred solid epoxy resins are epoxy resins in the narrower sense, i.e., those with an index s of > 1.5.

[0057] For liquid epoxy resins, the index s has a value less than 1. Preferably, s has a value less than 0.2.

[0058] Therefore, they are preferably diglycidyl ethers of bisphenol A (DGEBA), bisphenol F, and bisphenol A / F. Liquid resins of this type are available, for example, as Araldite® GY 250, Araldite® PY 304, Araldite® GY 282 (Huntsman), DER™ 331 or DER™ 330 (Dow), or Epikote 828 (Hexion).

[0059] The epoxy resin A is preferably a solid epoxy resin of formula (II).

[0060] The heat-curing, one-component epoxy resin composition further comprises at least one latent hardener for epoxy resins. Latent hardeners are essentially inert at room temperature and are activated by elevated temperature, typically at temperatures of 70°C or more, thereby initiating the curing reaction. Conventional latent hardeners for epoxy resins can be used. A nitrogen-containing latent epoxy resin hardener is preferred.

[0061] The latent hardener is preferably selected from dicyandiamide, guanamines, guanidines, aminoguanidines and derivatives thereof, substituted ureas, imidazoles, and amine complexes, preferably dicyandiamide. The latent hardener is preferably used in a stoichiometric amount based on the epoxy groups in the composition. The molar ratio of the epoxy groups to the active hydrogen of the latent hardener is preferably 0.8 to 1.2, in particular 0.9 to 1.1, preferably 0.95 to 1.05.

[0062] The proportion of the latent hardener is preferably 0.1 to 15 wt.%, particularly preferably 0.2 to 5 wt.%, in particular 0.5-3 wt.%, based on the total weight of the epoxy resin composition.

[0063] The one-component, heat-curing epoxy resin composition optionally contains at least one toughener D. The tougheners D can be solid or liquid. In particular, the toughener D is selected from the group consisting of terminally blocked polyurethane polymers D1, liquid rubbers D2, and core-shell polymers D3.

[0064] The proportion of toughener D is preferably 5-30 wt. %, particularly preferably 7.5-20 wt. %, based on the total weight of the epoxy resin composition.

[0065] In a preferred embodiment, the one-component, heat-curing epoxy resin composition further comprises at least one filler F. Preferred fillers are mica, talc, kaolin, wollastonite, feldspar, syenite, chlorite, bentonite, montmorillonite, calcium carbonate (precipitated or ground), dolomite, quartz, silicas (fumed or precipitated), cristobalite, calcium oxide, aluminum hydroxide, magnesium oxide, ceramic hollow beads, glass hollow beads, organic hollow beads, glass beads, glass fibers, and color pigments. Particular preference is given to fillers selected from the group consisting of calcium carbonate, calcium oxide, talc, glass fibers, and fumed silicas, more preferably talc, glass fibers, and fumed silicas. The total proportion of the total filler F is advantageously 3-50 wt.%, preferably 5-40 wt.%, 8-35 wt.%, based on the total weight of the epoxy resin composition.

[0066] The one-component thermosetting epoxy resin composition comprises at least one physical or chemical blowing agent BA.

[0067] Chemical blowing agents are organic or inorganic substances that form or release gaseous substances under the influence of temperature, humidity, electromagnetic radiation or chemicals. Such substances include, in particular, azodicarbonamides, sulfohydrazides, bicarbonates or carbonates. Physical blowing agents can be compounds that, for example, change into the gaseous state upon changes in temperature, pressure or volume, in particular upon increase in temperature, and thus form a foam structure through volume expansion. Such physical blowing agents are, in particular, liquids that evaporate at elevated temperatures. Furthermore, gases or low-boiling liquids can be used as physical blowing agents and are introduced into the composition in microencapsulated form. Both chemical and physical blowing agents are capable of creating foam structures in polymer compositions.

[0068] The at least one physical or chemical blowing agent BA preferably has an activation temperature of 120 °C to 220 °C, preferably of 140 °C to 200 °C.

[0069] The proportion of the blowing agent BA is advantageously 0.1-10 wt.%, preferably 0.5-5 wt.%, in particular 1-3 wt.%, based on the total weight of the epoxy resin composition. A particularly preferred one-component thermosetting epoxy resin composition comprises:

[0070] -30 - 90 wt.%, 35 - 85 wt.%, 40 - 75 wt.%, particularly preferably 45 - 60 wt.%, based on the total weight of the heat-curing epoxy resin composition, of the at least one epoxy resin A has on average more than one epoxy group per molecule;

[0071] -0.1 to 15% by weight, particularly preferably 0.2 to 5% by weight, in particular 0.5 to 3% by weight, based on the total weight of the heat-curing epoxy resin composition, of the at least one latent hardener for epoxy resins, more particularly dicyandiamide;

[0072] - 0.1-10 wt.%, preferably 0.5-5 wt.%, in particular 1-3 wt.%, based on the total weight of the thermosetting epoxy resin composition, of the blowing agent BA;

[0073] -preferably 5 - 30 wt.%, preferably 7.5 - 20 wt.% of at least one toughener D, based on the total weight of the thermosetting epoxy resin composition;

[0074] -preferably 5-40 wt.%, preferably 20-40 wt.%, based on the total weight of the thermosetting epoxy resin composition, of a filler F selected from the group consisting of calcium carbonate, calcium oxide, talc, glass fibers and fumed silicas, more preferably talc, glass fibers and fumed silicas;

[0075] -optionally 3-50 wt.%, preferably 5-40 wt.%, in particular 8-35 wt.%, based on the total weight of the heat-curing epoxy resin composition, of at least one flame-retardant component G selected from the list consisting of ammonium phosphate, ammonium pyrophosphate, ammonium polyphosphate, melamine phosphate, magnesium sulfate and boric acid, preferably ammonium polyphosphate.

[0076] Furthermore, it may be advantageous if the preferred one-component heat-curing

[0077] Epoxy resin composition consists of more than 80 wt.%, preferably more than 90 wt.%, in particular more than 95 wt.%, particularly preferably more than 98 wt.%, based on the total weight of the epoxy resin composition, of the aforementioned components.

[0078] Details and advantages of the invention are described below using exemplary embodiments and with reference to schematic drawings. They show:

[0079] Fig. 1 is an exemplary representation of a passage;

[0080] Fig. 2 is an exemplary representation of a passage with an insulating element arranged therein; and

[0081] Fig. 3a to 6b show exemplary representations of systems of insulated passages.

[0082] Fig. 1 shows an example of a passage 5 in an electrically powered motor vehicle. The passage 5 connects a first region 9 to a second region 10. The first region 9 is permeable to air toward a battery of the motor vehicle, and the second region 10 is permeable to air toward a passenger compartment of the motor vehicle. In this exemplary embodiment, the passage 5 is designed as a channel-shaped passage, with side walls 6 surrounding a hollow space. Arrows also indicate the direction in which hot and toxic gas spreads in the event of a thermal runaway of the motor vehicle's battery.

[0083] Fig. 2 again shows a passage 5 in an electrically powered motor vehicle. However, in Fig. 2, this passage 5 is now insulated by an insulating element 2. This insulating element 2 prevents hot and toxic gases from spreading from the first area 9 to the second area 10. This is represented in this figure by a dashed and crossed arrow.

[0084] Exemplary and possible embodiments of such insulation elements 2 are now shown schematically and incompletely in the following figures. For each exemplary embodiment, the system 1 is shown once in a state before expansion of the expandable material 3 and once after expansion of the expandable material 3. The systems 1 after expansion, i.e., with the expanded material 3', are each referred to as system 1'.

[0085] 3a and 3b show a first exemplary system 1 or 1'. In this exemplary embodiment, the passage 5 is again channel-shaped with side walls 6. The insulating element 2 is positioned in this passage such that the expanded material 3' closes the passage. The expanded material is oriented towards the first region 9. In this exemplary embodiment, the insulating element 2 comprises both expandable material 3 or expanded material 3' and a carrier 4. In this exemplary embodiment, this carrier 4 also has a clip, which simplifies positioning in the region of the passage.

[0086] In Fig. 3a, a main passage direction 11 through the passage 5 is shown. In this embodiment, this main passage direction 11 runs essentially parallel to the side walls 6.

[0087] Figs. 4a and 4b show another example of a system 1 or 1' of an insulated passageway. In contrast to the exemplary embodiment in Figs. 3a and 3b, neither the support 4 nor the expandable material 3 form a continuous surface on the side of the first region 9 prior to expansion of the material. However, it can be seen from Fig. 4b that, when the system 1' is in use, the expanded material 3' completely closes the passageway 5 toward the first region 9. This fully fulfills the insulating effect of the insulating element 2 against hot and toxic gases.

[0088] Figs. 5a and 5b now show an insulating element 2 that does not include a support. In this exemplary embodiment, the insulating element 2 is fixed to a structure in the region of the passage 5 by an adhesive layer. Once again, the expanded material 3' completely closes the passage 5 when the system 1' is in use.

[0089] Finally, Figs. 6a and 6b show a further embodiment of a system 1 or 1', respectively. In this embodiment, the passage 5 is hole-shaped, wherein the passage 5 is formed by an opening 8 in a wall 7. In this embodiment, the main passage direction 11 runs substantially perpendicular to the wall 7.

[0090] Here, the insulating element 2 again comprises a carrier 4 and expandable material 3 or expanded material 3'. After expansion of the expandable material 3, the expanded material closes the passage 5 against the first region 9, as can be seen in Fig. 6b.

[0091] List of reference symbols

[0092] 1 system (before a usage state)

[0093] 1' System (in a state of use) 2 Insulation element

[0094] 3 expandable material

[0095] 3' expanded material

[0096] 4 carriers

[0097] 5 Passage 6 Side wall

[0098] 7 Wall

[0099] 8 Opening

[0100] 9 first area

[0101] 10 second area 11 main passage axis

Claims

Patent claims 1. A system (1') of an insulated passage (5) in an electrically powered motor vehicle, the system (1') comprising: a passage (5) which connects a first region (9) to a second region (10), wherein the first region (9) is permeable to air towards a battery of the motor vehicle and wherein the second region (10) is permeable to air towards a passenger compartment of the motor vehicle; and an insulating element (2) which comprises an expanded material (3'), wherein the expanded material (3') closes the passage (5) towards the first region (9); wherein the expanded material (3') is a foamed and at least partially cured epoxy resin composition.

2. System (1') according to claim 1, wherein the passage (5) is channel-shaped, and / or wherein the passage (5) is formed by side walls (6) surrounding a cavity.

3. System (1') according to claim 1, wherein the passage (5) is hole-shaped, and / or wherein the passage (5) is formed by an opening (8) in a wall (7).

4. System (1') according to one of the preceding claims, wherein only expanded material (3') is exposed from the insulating element (2) to the first region (9).

5. System (1') according to one of the preceding claims, wherein the expanded material (3') has a layer thickness, measured in a direction along a main passage axis (11) of the passage (5), between 1 and 50 mm.

6. System (1') according to one of the preceding claims, wherein the expanded material (3') has a volume between 50% and 1200% greater than before expansion.

7. System (1') according to one of the preceding claims, wherein the expanded material (3') was present before expansion as an expandable material (3) which contained the following composition: One-component thermosetting epoxy resin composition comprising a) at least one epoxy resin A having on average more than one epoxy group per molecule; b) at least one latent hardener for epoxy resins; and c) at least one physical or chemical blowing agent BA.

8. System (1') according to one of the preceding claims, wherein the insulating element (2) comprises a support (4).

9. System (1') according to claim 8, wherein the carrier (4) is designed as a film and / or wherein the carrier (4) is designed to be flexible and / or wherein the carrier (4) is formed from metal.

10. System (1') according to claim 8, wherein the carrier (4) is designed as a rigid carrier, and / or wherein the carrier (4) is made of plastic.

11. System (1') according to claim 10, wherein the carrier (4) and expanded material (3') were produced by a two-component injection molding process.

12. System (1') according to one of claims 1 to 7, wherein the insulating element (2) does not comprise a support (4).

13. System (1') according to claim 12, wherein the insulating element (2) is attached to a structure of the passage (5) by an adhesive film.

14. System (1') according to claim 12, wherein the insulating element (2) is attached to a structure of the passage (5) by a pushpin.

15. System (1') according to one of the preceding claims, wherein the system (1) is in a motor vehicle without an internal combustion engine.

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