Silicone Composites for High Temperature Insulation Applications

Abstract

To provide a silicone composite usable in high temperature application.SOLUTION: A silicone composite contains a silicone, and a pyrolytic inorganic filler decomposable at a temperature of 500°C or lower. The silicone composite forms at least partially an inorganic composite material when being exposed to a high temperature, and maintains its dimensional stability.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention is directed to a silicone composite comprising a silicone and an inorganic filler, which when exposed to elevated temperatures at least partially forms an inorganic composite and maintains its dimensional stability. [Background technology]

[0002] Many applications require insulation that can withstand high temperatures. Ceramic or glass materials are commonly used as high-temperature insulating materials. Ceramic or glass materials also have a relatively high stiffness and hardness, which makes them difficult to use in many applications. These materials are relatively brittle, which makes them unusable in applications where vibratory forces are present. Furthermore, these ceramic or glass materials are more expensive to manufacture than other materials.

[0003] Plastic materials consist of a variety of synthetic or semi-synthetic organic compounds. Plastic materials are generally malleable and can be easily formed into solid objects. Plastics generally have good insulating properties at low temperatures, generally below 300°C, and cannot be used as insulating materials at higher temperatures. Plastic materials are generally less expensive to manufacture than ceramic or glass materials.

[0004] Due to their physical and electrical properties, silicone composites are used as insulating materials in a wide variety of fields. It is known that coating electrical wires and cables with silicone rubber or silicone composites improves their physical strength and electrical insulation properties. However, these silicone rubber or silicone composite wire or cable coatings burn off when exposed to temperatures above 500°C, resulting in a deterioration or loss of electrical insulation performance and mechanical stability. Therefore, these silicone composites are not suitable for high-temperature applications where the composite must maintain its shape, have sufficient strength, and retain its electrical insulation properties.

[0005] U.S. Patent No. 4,269,753 (Mine et al.) describes a siloxane composition that can be converted to an elastomer or resin at normal curing temperatures, but which ceramizes upon firing to higher temperatures to form a flexible ceramic having electrical insulating properties and excellent physical properties. The composition consists essentially of (a) through (e) of the following: (a) RSiO 1 / 2 100 parts by weight of a siloxane copolymer consisting essentially of units, where R is a monovalent organic group having 1 to 10 carbon atoms and containing at least two unsaturated groups and at least two alkoxy groups bonded to silicon atoms per molecule. (b) 0 to 600 parts by weight of a linear or branched organopolysiloxane polymer having at least two unsaturated groups bonded to silicon atoms per molecule. (c) an organopolysiloxane having at least two hydrogen atoms bonded to silicon atoms per molecule; (d) 3 to 300 parts by weight of a ceramic-forming filler material. (e) a catalytic amount of an addition reaction catalyst, wherein the molar ratio of silicon-bonded hydrogen atoms to silicon-bonded unsaturated groups in components (a), (b), and (c) is from 0.5 / 1 to 10 / 1, and the total number of unsaturated groups in components (a) and (b) and the total number of silicon-bonded hydrogen atoms in component (c) is at least 5. When a solid substrate is coated with this composition and heated to 500°C or above, the composition forms a ceramic. The ceramic-forming filler material is not thermally decomposable.

[0006] The paper "Investigation of Ceramifying Process of Modified Silicone-Silicate Compositions," J Mater Sci, 42(15), 6046-6055, August 2007, describes the addition of glass frit to silicone-based composites to improve low-temperature ceramification at elevated temperatures. The paper concludes that the glass frit melts below the mica-silica eutectic temperature and combines with the inorganic filler and the thermal decomposition products of the silicone rubber to aid in the formation of ceramic. The glass frit reacts with the filler and silica matrix to form an intermediate liquid phase, which binds the filler and silica matrix together and provides strength to the char.

[0007] International Publication No. WO 2010 / 097705 A1 (Nexans) describes a fire-retardant material and a cable containing the material. The publication describes a fire-retardant material comprising a polymer, including a silicone polymer, and a calcium carbonate filler, the calcium carbonate filler being present in the material in an amount such that a post-burn residue remains after the material is exposed to a flame, and the material contains less than 50 parts by weight of ceramizable filler per 100 parts by weight of polymer. Calcium carbonate has a high decomposition temperature of approximately 840°C. When exposed to a flame, the mixture decomposes to provide a protective layer.

[0008] The paper "The Thermal Stabilization and Ceramifying of Silicone Rubbers," International Polymer Science and Technology, 43(4), T33-T40, April 2016, discusses the need to find additives, fillers, and catalysts that will substantially extend the service life of siloxane elastomer composites at temperatures above 300°C or promote the formation of ceramic-like materials using combustion processes. Silicone rubber has high heat resistance and does not release toxic products upon thermal degradation or combustion. Additives, fillers, and catalysts are added to silicone rubber, which is then processed in conventional extrusion equipment to form sheets, profiles, or coatings. Under flame conditions, this composite can form a ceramic heat-resistant material. Many of these composites use platinum as an additive to enhance flame resistance.

[0009] The paper also describes a method for producing cables with a ceramized silicon sheath based on silicone elastomer, calcium carbonate, and additional glass-forming fillers. Upon exposure to flame, the sheath decomposes, providing a protective or electrically insulating layer on the lead wires. Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, it would be advantageous to provide a silicone composite that can be used in high-temperature applications. Preferably, it would be advantageous to provide a silicone composite that can maintain its insulating properties with good dimensional stability for at least about 15 minutes below 500°C and at least about 10 seconds at 1200°C, or at least about 30 minutes below 500°C and at least 10 seconds at 1200°C. More preferably, it would be advantageous to provide a silicone composite that can maintain its insulating properties with good dimensional stability without using a combustion process to form the composite. Still further, it would be advantageous to provide a method for forming a silicone composite that can be used in high-temperature applications, and an article formed from such a silicone composite. [Means for solving the problem]

[0011] Some embodiments are directed to silicone composites with thermally decomposable inorganic fillers that can be processed and used in high temperature insulation applications, where the silicone composite at least partially forms an inorganic composite while maintaining its strength and shape upon exposure to high temperatures, and shrinks by 25% or less.

[0012] One embodiment is directed to a device comprising a first metal portion, a second metal portion, an optional polymer layer, and an insulating layer, wherein the first metal portion and the second metal portion are separated from each other by a polymer layer and / or an insulating layer between the first metal portion and the second metal portion, the insulating layer being spatially located between one of the metal portions and the polymer layer or between the two metal portions, and the insulating layer being a silicone composite comprising silicone and an inorganic filler that can be decomposed at a temperature of 500° C. or less.

[0013] Some embodiments are directed to a connector, circuit protection device, relay device, battery package, power distribution unit, or battery disconnection unit comprising a first metal portion, a second metal portion, an optional polymer layer, and an insulating layer, wherein the first metal portion and the second metal portion are separated from each other by a polymer layer spatially located between the first metal portion and the second metal portion, and the insulating layer is spatially located between one of the metal portions and the polymer layer or between the two metal portions, and the insulating layer is a silicone composite including silicone and an inorganic filler that can be decomposed at a temperature of 500° C. or less.

[0014] Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a flow chart illustrating the steps used to form a silicone composite. [Figure 2] 1 is a flow chart showing a process by which a silicone composite is converted into an inorganic composite that can withstand high temperatures while maintaining its strength and dimensional stability. [Figure 3] 1 is a photograph of a molded sample of a silicone composite containing inorganic filler. [Figure 4] This is a photograph showing a molded sample of a silicone composite material containing inorganic filler that was exposed to high temperature for 30 minutes without load. [Figure 5] Photographs of molded samples of silicone composites containing inorganic fillers exposed to high temperatures under load for 30 minutes. [Figure 6] Photographs of molded samples of silicone composites containing inorganic fillers exposed to high temperatures under load for 60 minutes. [Figure 7]This is a photograph showing a molded sample of a silicone composite material containing inorganic filler that was exposed to 1200°C for 1 minute without load. [Figure 8] 1 is a photograph showing a state in which a molded sample (comparative example) of a high-temperature heat-resistant polymer material was exposed to 1200° C. for 1 minute under no load. [Figure 9] 1 is a photograph of a molded sample of an epoxy composite containing inorganic filler (comparative example). [Figure 10] 1 is a photograph of a molded sample of epoxy composite (comparative example) exposed to high temperature and load for 30 minutes. [Figure 11] 1 is a photograph of a molded sample of a polyolefin composite material containing an inorganic filler (comparative example). [Figure 12] 1 is a photograph of a molded sample of a polyolefin containing an inorganic filler (comparative example) exposed to high temperature under load, and a photograph of a molded sample of a polyolefin containing an inorganic filler (comparative example) exposed to high temperature without load. [Figure 13] Figures 13(a)-13(f) are schematic diagrams of possible configurations of metal, polymer and insulating layers used to form devices according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] The description of illustrative embodiments consistent with the principles of the present invention is intended to be read in connection with the accompanying drawings, which are to be considered a part of this written description in their entirety. Any reference to direction or orientation in the description of the embodiments of the present invention disclosed herein is intended merely for convenience of description and is not intended to limit the scope of the invention in any way. Relative terms such as "lower," "upper," "horizontal," "vertical," "upward," "below," "on," "below," "top," and "bottom," as well as derivatives thereof (e.g., "horizontally," "downward," "upwardly," etc.), should be construed as referring to the orientation shown in the drawings then being described or discussed.

[0017] These relative terms are for convenience of description only and do not require that the devices be constructed or operated in a particular orientation unless expressly stated to be so. Terms such as "mounted," "fixed," "connected," "coupled," "interconnected," and the like refer to both a directly or indirectly fixed or attached relationship of structures to one another by intervening structure, and a movable or rigid attachment or relationship, unless expressly stated otherwise.

[0018] Furthermore, the features and advantages of the present invention are described with reference to preferred embodiments. Therefore, the present invention should obviously not be limited to such embodiments, which illustrate some possible non-limiting combinations of features that may exist alone or in other combinations of features, and the scope of the present invention is defined by the claims appended hereto.

[0019] A new insulating material is provided that can maintain its insulating properties with good dimensional stability for at least 5, 10, 15, 30, or 60 minutes at 450°C, 500°C, or 650°C; and for at least 5, 10, 20, 30, or 60 seconds at 1100°C, 1200°C, or 1300°C. The new insulating material can provide insulating performance similar to that of plastic, glass, and ceramic. In one embodiment, the new insulating material is flexible, having a hardness of Shore D90 or less (including Shore D70 or less, Shore D50 or less), is formable, and is easier and less expensive to manufacture than ceramic or glass. The insulating material can be molded, cast, laminated, extruded, or dispensed into different shapes depending on its end-use application. Furthermore, the new insulating material combines the properties of plastic and ceramic or glass. The novel insulating material is made from a silicone composite, which, due to the inherent properties of silicone, is more flexible than most plastics and retains its shape and strength like a ceramic after exposure to high temperatures.

[0020] The novel silicone composite is formed from a silicone polymer and an inorganic filler. Upon exposure to high temperatures, the novel silicone composite at least partially converts to an inorganic composite, allowing it to be used as insulation in applications requiring stable insulation. In some embodiments, the silicone composite can at least partially convert to an inorganic composite at temperatures of 500°C or higher. In other embodiments, the silicone composite can at least partially convert to an inorganic composite at temperatures of 500°C or lower, for example, from about 350°C to less than 500°C (including temperatures from 400°C to less than 500°C). Such low-temperature converted inorganic composites help the silicone composite maintain good dimensional stability over a very wide temperature range, from about 500°C to about 1300°C. In certain embodiments, the conversion is achieved by heating the composite. No flame, ignition, or other combustion process is used. In this embodiment, the conversion process is also free of an intermediate liquid state, which is very important for some applications where the insulating silicone composite will be under stress, as discussed below. In certain embodiments, the silicone composite does not contain glass frit.

[0021] The silicone used in the silicone composite can be any silicone elastomer or polymer containing alternating chains of silicon and oxygen atoms. The silicone can be liquid silicone rubber (LSR), high viscosity rubber (HCR), fluorosilicone, polyhedral oligomeric silsesquioxane (POSS), silicone polyamide, silicone polyurethane, silicone epoxy, or other silicones. Examples of suitable silicones are LSR2660 and LSR7060 from GE Silicones. The type of silicone used depends on the end-use application. The silicone used in the silicone composite can also contain other additives depending on the final desired end use. Examples of suitable additives include fumed silica, antioxidants, fluxes, or catalysts. Suitable antioxidants include phenolic antioxidants or amine antioxidants. Examples of suitable fluxes include NH4F, NH4Cl, and Na2B4O7. Possible catalysts that can be used include peroxides or platinum catalysts.

[0022] The silicone is then compounded with the inorganic filler. Any known mixing device can be used to mix the silicone with the inorganic filler to form a homogeneous mixture. Examples of mixing devices include a FlackTek Speed ​​Mixer, a Ross mixer, a kneader mixer, a two-roll mixer, a three-roll mill, or any other device that can mix two materials.

[0023] The inorganic filler used in the present invention can be any inorganic filler. Preferably, the inorganic filler can be decomposed at a temperature of 500°C or less. Examples of possible inorganic fillers that can be used include, but are not limited to, magnesium hydroxide, magnesium carbonate, calcium hydroxide, sodium bicarbonate, potassium bicarbonate, aluminum hydroxide, and mixtures thereof. The inorganic filler comprises about 10% to about 90% by weight of the silicone composite, preferably about 30% to about 90% by weight, or about 50% to about 85% by weight. More preferably, magnesium hydroxide and aluminum hydroxide are used due to their flame-retardant properties. In one embodiment, it is preferred to use at least 30% by weight of magnesium hydroxide or aluminum hydroxide to achieve the desired results. The inorganic filler preferably has a particle size of 20 microns or less, 10 microns or less, more preferably 5 microns or less, and most preferably 3 microns or less, specifically, for magnesium hydroxide, the particle size is 10 microns or less, more preferably 5 microns or less, and most preferably 3 microns or less.

[0024] After silicone and inorganic filler are mixed, they are processed into a processed composition having a desired shape.Any conventional molding, casting, lamination, extrusion or dispensing process can be used to achieve the desired shape of the processed composition.Examples of suitable molding processes include injection molding, overmolding or compression molding.In some embodiments, the mixed silicone and inorganic filler are dispensed into a desired shape.

[0025] The treated composition is then cured to yield a silicone composite. While curing can occur at room temperature, it is preferred to cure the composition at a temperature ranging from about 50 to 200°C. The type of cure used and the curing conditions depend on the type of silicone used. For example, silicone composites can be cured by moisture, ultraviolet light, or by exposing the composite to elevated temperatures.

[0026] Silicone composites can be used in a variety of applications. Silicone composites are flexible and moldable. Silicone composites formed according to the present invention maintain their shape, strength, and dimensional stability when exposed to high temperatures up to 1300°C, shrinking by 25% or less (including 20% ​​or less or 15% or less). It is desirable for there to be expansion rather than shrinkage. For the purposes of the present invention, expansion of any dimension is not considered a change in dimensional stability. Silicone composites can shrink by 5x10 at temperatures above 500°C. 4 It retains its shape under a load of N / square meter (1×10 4 N / square meter or less or 1×10 3 (Including loads of less than N / m²). Without being limited to any one theory, it is believed that when a silicone composite is exposed to high temperatures, two additional reactions occur: First, the silicone in the silicone composite is converted to silicon oxide (SiO x ) is reduced to This silicon oxide then reacts with the inorganic filler or its decomposed components, thereby forming an inorganic composite that has excellent dimensional stability, strength, and insulating properties.

[0027] Another aspect of the present invention is a device formed using a silicone composite. In one embodiment, the device comprises a first metal portion, a second metal portion, an optional polymer layer, and an insulating layer comprising the silicone composite of the present invention. The polymer layer can be any polymer layer that can be formed to a desired shape and thickness. The polymer layer can be selected from the group including polybutylene terephthalate (PBT), nylon, polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyetherimide (PEI), polyether ether ketone (PEEK), polycarbonate (PC), and acrylonitrile butadiene styrene (ABS). The first metal portion and the second metal portion are separated from each other. The polymer layer is spatially positioned between the first metal portion and the second metal portion. An insulating layer may be between at least one of the metal portions and the polymer layer, or between the two metal portions if no polymer layer is present. Alternatively, an air gap may be disposed between the two metal layers and the insulating layer.

[0028] 13(a)-13(f) are schematic diagrams of various embodiments of a device formed from a silicone composite. As can be seen for the various embodiments, 1 and 2 are metal portions, 3 is a polymer layer, and 4 is an insulating layer. It should be noted that the metal portions and layers do not need to be in contact with each other. In other words, there may be gaps between the metal portions or layers, as shown, for example, in FIG. 13(e). Alternative embodiments are possible, so long as the embodiment includes a silicone composite as described herein. The metal layer can be made of any suitable metal. Examples of suitable metals include copper, copper alloy, aluminum, or aluminum alloy. The insulating layer of the device is a silicone composite. The insulating layer of the device has a thickness of, for example, less than 5 mm (including less than 2 mm, including less than 1 mm). The silicone composite includes silicone and an inorganic filler that can be decomposed at temperatures of 500°C or less. When the insulating layer is exposed to high temperatures, the silicone composite at least partially forms an inorganic composite with good dimensional stability. The device can be, for example, a connector, a circuit protection device, a relay device, or a battery package. Any other type of device with desired qualities can be fabricated from this silicone composite.

[0029] Silicone composites can be used in any application requiring mechanical strength and electrical insulation when the silicone composite is exposed to high temperatures. The size of the composite depends on the end-use application. Furthermore, processing conditions also vary depending on the end-use of the composite. For example, the silicone composites of the present invention can be used in traction batteries to insulate aluminum bus bars used for cell connection. Without insulation, excessive heat generated by one cell could spread to other cells or the entire battery assembly. This could result in deformation of the soft, low-melting-point aluminum bus bars, potentially causing a short circuit. Using the silicone composites of the present invention as insulation for aluminum bus bars protects the circuit from short circuits and even fire.

[0030] Example In this example, LSR2660 silicone rubber was mixed with magnesium hydroxide in a FlackTek Speed ​​Mixer DAC 150.1 FVZ centrifugal mixer to form a silicone composite with 50 wt. % magnesium hydroxide. After mixing, the paste was compression molded to the desired thickness. The product was then cured at 180°C for 30 minutes to form the silicone composite. Figure 3 shows a photograph of a sample molded from the silicone composite. Figure 4 shows the sample after 30 minutes in an oven at 500°C without load. Figure 5 shows the silicone composite sample after 30 minutes in an oven at 500°C under a load of 3700 Pa. Figure 6 shows the same sample as in Figure 3 after a total of 60 minutes in an oven at 500°C under load. Figures 3-6 demonstrate that the silicone composite sample can still maintain its original shape when exposed to 500°C for 30 to 60 minutes, with or without load. This example demonstrates that the silicone composite of the present invention forms an inorganic composite when exposed to high temperatures and can be used for high temperature applications both under load and without load.

[0031] In another example, LSR2660 silicone rubber was mixed with magnesium hydroxide in a FlackTek Speed ​​Mixer DAC 150.1 FVZ centrifugal mixer to form a silicone composite with 50 wt. % magnesium hydroxide. After mixing, the paste was compression molded to the desired thickness. The product was then cured at 180°C for 30 minutes to form the silicone composite. Figure 7 shows a sample of the composite that was first held in an oven at 500°C for 15 minutes, then baked in an oven at 1200°C for 1 minute. This example demonstrates that the silicone composite of the present invention forms an inorganic composite when exposed to high temperatures, and can be used for high-temperature applications, both under and without load.

[0032] As comparative examples, the following series of high temperature resistant polymer materials were injection molded to the desired dimensions of 50 mm x 10 mm x 1 mm. Sabic Ultem® 2300 polyetherimide Vitrex® PEEK 450GL30 from Vitrex PEEK / Ultem blend (70% by weight / 30% by weight) Blend of PEEK and PPS (Celanese's Fortron® polyphenylene sulfide SF3001) (70% by weight / 30% by weight) Figure 8 shows a photograph of the molded high-temperature resistant polymer materials that were first held in a furnace at 500°C for 15 minutes and then baked in a furnace at 1200°C for 1 minute. These materials were completely burned out after 1 minute of exposure to 1200°C. These comparative examples clearly demonstrate that even high temperature resistant polymeric materials do not produce the same results as the composites of the present invention achieve.

[0033] In this comparative example, EPO-TEK® 337 epoxy from Epoxy Technology, Inc. was mixed with magnesium hydroxide to obtain a composite composition with 50 wt. % magnesium hydroxide. The epoxy composite was molded and cured at 150°C for 60 minutes. Figure 9 shows a photograph of the molded epoxy composite. The epoxy composite was exposed to 500°C in an oven for 30 minutes with no load, causing the epoxy composite to disintegrate into inorganic powder. The results of the epoxy sample at high temperature with no load are shown in Figure 10. As can be seen in Figure 10, the epoxy composite lost its shape and strength. This comparative example demonstrates that inorganic-filled epoxy does not result in the same properties achieved with the silicone composite of the present invention.

[0034] In this third example, SP1540, a grade of low-density polyethylene from Prime Polymer Co., Ltd., was mixed with magnesium hydroxide, an inorganic filler. The polyolefin composite contained 70% magnesium hydroxide by weight and was mixed in a Brabender mixer at 120°C for 30 minutes. The composite was compression molded at 120°C to obtain two samples. Figure 11 is a photograph of the molded polyethylene composite sample. Two samples of this polyethylene composite were then placed in a 500°C oven for 30 minutes, one under a load of approximately 1000 Pa and the other unloaded. Figure 12 shows that the polyethylene composite disintegrates and turns to ash at high temperatures, both under and without load. This comparative example demonstrates that polyolefins filled with inorganic fillers do not ultimately have the same properties achieved with the silicone composites of the present invention.

[0035] While the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention as defined in the appended claims. Those skilled in the art will recognize that the present invention may be used with many modifications of the structure, arrangement, proportions, sizes, materials, and components used in carrying out the invention, as well as other modifications, which are specifically adapted to particular environmental and operational requirements without departing from the principles of the invention. The embodiments disclosed herein are therefore to be considered in all respects as illustrative and not restrictive, the scope of the present invention being defined by the appended claims and not limited to the description or embodiments described above.

Claims

1. 1. A device comprising a first metal portion, a second metal portion, and a polymer layer, the first metal portion and the second metal portion are separated from each other; the polymer layer is spatially located between the first metal portion and the second metal portion; an insulating layer spatially located between one of the first metal portion and the second metal portion and the polymer layer; the insulating layer is a silicone composite material containing silicone and an inorganic filler that is decomposable at a temperature of 500°C or less, the silicone composite forms an inorganic composite having good dimensional stability when exposed to high temperatures; The inorganic filler includes magnesium hydroxide, and The amount of the inorganic filler is 30% to 90% by weight of the silicone composite. Device.

2. An apparatus comprising a first metal part, a second metal part, and a polymer layer, the first metal portion and the second metal portion are separated from each other; the polymer layer is spatially located between the first metal portion and the second metal portion; an insulating layer spatially located between one of the first metal portion and the second metal portion and the polymer layer; the insulating layer is a silicone composite material containing silicone and an inorganic filler that is decomposable at a temperature of 500°C or less, the silicone composite forms an inorganic composite having good dimensional stability when exposed to high temperatures; the inorganic filler is selected from the group comprising magnesium hydroxide, aluminum hydroxide, calcium hydroxide, magnesium carbonate, and mixtures thereof; and The amount of the inorganic filler is 30% to 90% by weight of the silicone composite. Device.

3. the device is part of a connector, a circuit protection device, a relay device, or a battery package; 10. The apparatus of claim 1.

4. the device is part of a connector, a circuit protection device, a relay device, or a battery package; 3. The apparatus of claim 2.

5. the insulating layer remains insulating and retains its shape under load when exposed to temperatures greater than 500°C; 5. An apparatus according to any one of claims 1 to 4.

6. The insulating layer remains insulating and retains its shape when exposed to a temperature of 500°C for at least 15 minutes.

5. An apparatus according to any one of claims 1 to 4.

7. The insulating layer remains insulating and retains its shape when exposed to a temperature of 1200°C for at least 10 seconds.

5. An apparatus according to any one of claims 1 to 4.

8. The insulating layer is overmolded, cast, laminated, inserted, or dispensed directly onto the polymer layer; 8. An apparatus according to any one of claims 1 to 7.

9. The insulating layer maintains its dimensional stability when exposed to high temperatures and shrinks by no more than 25%.

9. An apparatus according to any one of claims 1 to 8.

10. the insulating layer has a thickness of less than 2 mm; 10. An apparatus according to any one of claims 1 to 9.

11. The first metal part or the second metal part is made of aluminum or an aluminum alloy.

11. An apparatus according to any one of claims 1 to 10.

12. The silicone composite can at least partially form an inorganic composite at a temperature of 500°C or less and maintain its dimensional stability.

3. The device according to claim 1 or 2.

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