JP6674178B2 - Insulation body, manufacturing method thereof, rocket motor, and heat storage layer forming body - Google Patents

Description

  The present invention relates to an insulation body for suppressing heat transfer from a high-temperature combustion gas and a method for manufacturing the same. Further, the present invention relates to a rocket motor having such an insulation body. Further, the present invention relates to a heat storage layer forming body that can be used for such an insulation body.

  Since the space in which the combustion gas is generated or flows is at a high temperature (for example, 1000 ° C. or more or 3000 ° C. or more), by providing an insulation body (insulating material) on the inner wall surface covering this space, the inner wall surface is thermally Protect. On such an inner wall surface, there is an inner wall surface of a motor case provided in the rocket motor.

  Rocket motors generate and emit solid propellant combustion gases. The rocket motor is provided on a satellite launch vehicle in one example, and propells the rocket with the jetted combustion gas.

  The rocket motor has a motor case having an internal space in which a propellant is provided. The propellant, when ignited, produces high temperature, high pressure combustion gases. This combustion gas is ejected to the outside from a nozzle provided in the motor case.

  In order to suppress such heat transfer from the combustion gas to the motor case, an insulation body is attached to the inner wall surface of the motor case. This protects the motor case from high-temperature combustion gas. Such an insulation body is described in, for example, Patent Documents 1 and 2 below.

Patent No. 4587767 Patent No. 5342369

  It is desirable to further reduce or delay the temperature rise of the motor case. For example, when the operation time of the rocket motor is made longer, or when the rocket motor is a two-stage thrust rocket motor as described below, it is desired to reduce or delay the temperature rise of the motor case.

  In a two-stage thrust rocket motor, the inner space of the motor case is separated into two spaces by a partition wall, and two propellants are provided in each space. One propellant is ignited and burned, and after a lapse of a set time after the completion of the combustion, the other propellant is ignited. In this case, even if the propellant is not burning during the set time, the internal space of the motor case is at a high temperature (for example, 3000 ° C. or higher). It is desired to protect the motor case from the high temperature in the internal space for a long time including the following.

Therefore, a first object of the present invention is an insulation body provided on an inner wall surface that covers an internal space in which combustion gas is generated or flows, wherein the temperature rise of the inner wall surface due to the combustion gas can be further reduced or delayed. An object of the present invention is to provide an insulation body and a method of manufacturing the same.
A second object of the present invention is to provide a rocket motor having such an insulation body.
Further, a third object of the present invention is to provide a heat storage layer forming body that can be used for such an insulation body.

According to the present invention, in order to achieve the first object, an insulation body provided on an inner wall surface that covers an internal space in which combustion gas is generated or flows,
A first layer, and a second layer disposed between the first layer and the inner wall surface,
The second layer is provided with an insulation body having a heat capacity of at least one of a unit volume and a whole larger than that of the first layer.

According to the present invention, in a state where the first layer having a relatively small heat capacity is located on the inner space side where the combustion gas is present and the second layer having a relatively large heat capacity is located on the inner wall surface side of the protection target, An insulation body can be used.
Since the first layer on the inner space side has a function of protecting the second layer, the second layer having a relatively large heat capacity stores heat from the inner space until the first layer is decomposed by the combustion gas and disappears. Thereby, the temperature rise of the inner wall surface can be reduced or delayed.

  The above-mentioned insulation body is preferably configured as follows.

  The second layer has a lower density than the first layer. This prevents the performance of the rocket motor from deteriorating due to an increase in mass.

  The first layer has higher heat resistance than the second layer. Thus, the first layer having high heat resistance can gain time until the first layer is decomposed by the combustion gas and disappears. Therefore, during that time, the second layer exhibits a function of storing heat from the internal space, and can suppress an increase in the temperature of the inner wall surface.

  The second layer contains a resin that contributes to its heat capacity.

  Since the second layer has a relatively large heat capacity and a lightweight resin, it can exhibit a function of storing heat from the internal space.

The first layer has an elastomer and a first filler,
The second layer has an elastomer and a second filler containing the resin.

  The mass of the resin accounts for 50% or more of the total mass of the second layer. Thereby, the heat capacity of the second layer can be sufficiently increased.

  The first filler of the first layer is an aramid fiber.

  According to another aspect of the present invention, there is provided a rocket including: a motor case having a propellant provided in an internal space; and the above-mentioned insulation body provided on an inner wall surface of the motor case. A motor is provided.

According to the present invention, in order to achieve the third object, a heat storage layer forming body for forming an insulation body provided on an inner wall surface that covers an internal space in which combustion gas is generated or flows,
At the time of use, it becomes the second layer of the first layer and the second layer of the insulation body, and is disposed between the first layer and the inner wall surface,
A heat storage layer forming body having a heat capacity of at least one of a unit volume and a whole larger than the first layer is provided.

  According to the present invention, there is provided a heat storage layer-forming body including an elastomer and a filler containing a resin.

In order to achieve the first object, according to the present invention, there is provided a method of manufacturing an insulation body for providing on an inner wall surface that covers an internal space in which combustion gas is generated or flows,
(A) a first composition is produced by mixing an elastomer, a first filler, and an additive;
(B) forming a first layer sheet by forming the first composition into a sheet shape;
(C) a second composition is produced by mixing an elastomer, a second filler containing a resin, and an additive,
(D) forming a second layer sheet by forming the second composition into a sheet,
(E) A method for manufacturing an insulation body is provided, in which an insulation body is obtained by laminating a first layer sheet and a second layer sheet on each other.

  According to the present invention, the insulation body provided on the inner wall surface covering the internal space in which the combustion gas is generated or flows has the first layer and the second layer. The first layer disposed on the inner space side can protect the second layer until the first layer is decomposed by the combustion gas and disappears. During this time, the second layer having a relatively large heat capacity stores heat from the internal space and suppresses heat transfer to the inner wall surface. Thereby, the temperature rise of the inner wall surface can be reduced or delayed.

1 shows a rocket motor according to an embodiment of the present invention and an insulation body provided on the rocket motor. 4 is a flowchart illustrating a method for manufacturing an insulation body according to an embodiment of the present invention. (A) is a graph which shows the density of an Example and Reference Examples 1-3, and (B) is a graph which shows the heat capacity of an Example and Reference Examples 1-3. (A) is a graph which shows the heat transfer analysis result when each laminated body using the layer of an Example and the reference examples 1-3 is attached to the inner surface of a motor case, and (B) is each graph. 6 is a graph showing the results of heat transfer analysis of FIG. 1 shows a two-stage thrust rocket motor provided with an insulation body according to an embodiment.

  An embodiment of the present invention will be described with reference to the drawings. In addition, the same reference numerals are given to the common parts in the respective drawings, and the duplicate description will be omitted.

  FIG. 1A shows a configuration of a rocket motor 20 according to the embodiment of the present invention. The rocket motor 20 generates and emits combustion gas of the solid propellant 5. The rocket motor 20 is provided on a rocket (for example, a rocket for launching an artificial satellite), a rocket for defense, or a missile, and propulses these by a jetting combustion gas. Alternatively, the rocket motor 20 is provided on a rocket (for example, an observation rocket) or an artificial satellite, and changes the attitude of the rocket motor 20 by the emitted combustion gas.

  The rocket motor 20 includes a motor case 3, a solid propellant 5, an ignition device 7, a nozzle 9, and an insulation body 10. A propellant 5 is provided in the internal space 3a of the motor case 3 (that is, the combustion chamber 3a). When the ignition device 7 ignites the propellant 5, high-temperature combustion gas is generated from the propellant 5. This combustion gas is ejected from the nozzle 9.

  The insulation body 10 has a sheet shape in the present embodiment. In the present embodiment, the insulation body 10 is a heat insulating material provided on the inner wall surface 3b of the motor case 3, as shown in FIG. The insulation body 10 is provided to protect the motor case 3 from the high temperature (in one example, about 3000 ° C.) of the combustion chamber 3a due to the combustion of the propellant 5.

  FIG. 1B is an enlarged view of a portion B surrounded by a broken line in FIG. The insulation body 10 has a first layer 10a and a second layer 10b. The first layer 10a is provided on the inner space 3a side, and the second layer 10b is provided on the inner wall surface 3b side, and is located between the first layer 10a and the inner wall surface 3b. For example, the second layer 10b is attached to the inner wall surface 3b.

  The first layer 10a has higher heat resistance than the second layer 10b. The heat resistance means a property in which at least one of decomposition, deterioration, deformation, and softening by heat (for example, decomposition) is small. In the present embodiment, the first layer 10a is composed of an elastomer, a first filler, and an additive. This elastomer has a function as a binder. The elastomer may be crosslinked. The first filler has a function of improving mechanical properties and heat resistance (for example, a property of reducing thermal decomposition). Here, the mechanical physical property means, for example, a property of suppressing a shape change of the first layer 10a due to a flow or a pressure of a combustion gas (the same applies hereinafter).

  The elastomer of the first layer 10a may be natural rubber, synthetic rubber, or a mixture of both. Specific examples of the elastomer include an ethylene-propylene-diene terpolymer having an unsaturated bond and capable of crosslinking, a natural rubber having a polyisoprene structure, and a chemical synthesis having the same polyisoprene structure as the natural rubber. Isoprene rubber, and acrylonitrile butadiene rubber which is a copolymer of acrylonitrile and butadiene. The elastomer of the first layer 10a may be any of these specific examples, or a mixture of two or more of these specific examples.

  The first filler may be reinforcing fibers, carbon black, asbestos, granular silica, or a mixture thereof. The reinforcing fiber is an aramid fiber (ie, an aromatic polyamide fiber) in a preferred example, but may be an aromatic polyamide-based pulp-like fiber (pulp-like aramid fiber), a carbon fiber, a glass fiber, or another fiber. . The reinforcing fibers may be a mixture of a plurality of types of fibers described above.

  Specific examples of the additive of the first layer 10a include a compounding agent for crosslinking for forming chain rubber molecules into a three-dimensional structure, a compound for adjusting hardness of a rubber product and improving kneading property and processability. There are softeners, plasticizers, anti-aging agents to prevent rubber deterioration, and processing aids and tackifiers to improve workability during kneading and rolling of rubber to obtain appropriate tackiness. . The additive of the first layer 10a may be any of these specific examples, or a mixture of two or more of these specific examples.

The second layer 10b has a larger heat capacity in at least one of the unit volume and the whole than the first layer 10a. In one example, the heat capacity of the unit volume of the second layer 10b is larger than the heat capacity of the unit volume of the first layer 10a. In another example, the overall heat capacity of the second layer 10b is larger than the overall heat capacity of the first layer 10a. In another example, the heat capacity of the unit volume of the second layer 10b is larger than the heat capacity of the unit volume of the first layer 10a, and the total heat capacity of the second layer 10b is the total heat capacity of the first layer 10a. Greater than. The second layer 10b has a resin that contributes to its heat capacity.
Further, the second layer 10b has a lower density than the first layer 10a.
The second layer 10b is made of resin in order to have a larger heat capacity and a lower density than the first layer 10a. This resin may be, for example, a phenolic resin or a polyamide resin, but may be another resin.

  The resin constituting the second layer 10b preferably accounts for 50% or more of the second layer 10b by weight. In a preferred example, the main material of the second layer 10b is a resin. Here, the main material means a material having the highest mass ratio among the materials forming the second layer 10b.

  In the present embodiment, the second layer 10b is composed of an elastomer, a second filler containing the above-described resin, and an additive.

  The elastomer of the second layer 10b has a function as a binder. The elastomer of the second layer 10b may be a natural rubber, a synthetic rubber, or a mixture of both. The elastomer of the second layer 10b may be any of the above specific examples of the elastomer of the first layer 10a, or a mixture of two or more of the above specific examples.

  The material having the highest mass ratio among the materials forming the second filler is the above-described resin. The resin of the second filler has a function of giving heat capacity to the second layer 10b. The second filler may include another material that improves the above-described mechanical properties (strength) and heat resistance. This other material preferably does not include the above-described reinforcing fibers that tend to create voids between the fibers. Thereby, the second layer 10b does not have a void inside. Therefore, the heat capacity of the second layer 10b is prevented from being reduced by the gap. The other material of the second filler is, for example, carbon black.

  FIG. 2 is a flowchart showing a method for manufacturing the above-described insulation body 10 of the present embodiment.

  This manufacturing method has steps S1 to S3.

  In step S1, a first layer sheet as the first layer 10a described above is manufactured. Step S1 has step S11 and step S12.

In step S11, the first composition is obtained by mixing the above-described elastomer, the first filler, and the additive as the material of the first layer 10a. Step S11 is performed, for example, as follows.
First, the first filler, the additive, and the crosslinkable solid elastomer are kneaded with a mixer. An additive (crosslinking agent) is added to the kneaded product, and the mixture is kneaded with a kneader. Thereby, a first composition for the first layer 10a is obtained.

  In step S12, a first layer sheet is obtained by forming the first composition into a sheet. For example, a first layer sheet is produced by passing the first composition through a calender roll machine.

  In step S2, a second layer sheet as the above-described second layer 10b is obtained. Step S2 includes step S21 and step S22.

In step S21, as the material of the second layer 10b, the above-described elastomer, a second filler containing a resin, and an additive are mixed to obtain a second composition. The preferred form of the elastomer and the second filler mixed at this time is a fine powder or a large number of small pieces. Step S21 is performed, for example, as follows.
First, the second filler, the additive, and the crosslinkable solid elastomer are kneaded with a mixer. An additive (crosslinking agent) is added to the kneaded product, and the mixture is kneaded with a kneader. Thereby, a second composition for the second layer 10b is obtained.

  In step S22, the second composition is formed into a sheet to obtain a second layer sheet. For example, a second layer sheet is prepared by passing the second composition through a calender roll machine.

  In step S3, the insulation body 10 is obtained by laminating the first layer sheet and the second layer sheet to each other. In the insulation body 10, the first layer sheet and the second layer sheet are joined to each other (for example, by an adhesive). For example, the insulation body 10 is obtained by attaching the surface of the first layer sheet and the surface of the second layer sheet to each other. The first layer sheet and the second layer sheet are the above-described first layer 10a and second layer 10b, respectively.

  The first layer sheet and the second sheet are heated at an appropriate timing to crosslink the elastomer of the first layer sheet and the second sheet.

(Heat storage layer forming body)
The above-described second layer 10b is a heat storage layer formed body according to the embodiment of the present invention. The heat storage layer forming body 10b constitutes the above-mentioned insulation body 10. The heat storage layer forming body 10b can be manufactured independently of the first layer 10a (for example, by the above-described step S2). When the heat storage layer forming body 10b is used as a component of the insulation body 10, that is, when the insulation body 10 is provided on the inner wall surface 3b, the heat storage layer forming body 10b is formed of the first layer 10a and the second layer 10b of the insulation body 10. The second layer 10b is provided between the first layer 10a and the inner wall surface 3b.

(Operation and effect of the embodiment)
The insulation body 10 according to the present embodiment includes a first layer 10a having relatively high heat resistance and a second layer 10b having relatively large heat capacity. The insulation body 10 is attached to the inner wall surface 3b such that the first layer 10a is located on the inner space 3a side and the second layer 10b is located on the inner wall surface 3b side.
The first layer 10a having relatively high heat resistance protects the second layer 10b from the combustion gas until it is decomposed by the combustion gas and disappears. Therefore, until the first layer 10a disappears, the second layer 10b having a relatively large heat capacity can reduce or delay the temperature rise of the motor case 3 by storing heat from the combustion gas.

As a result, for example, the following (1) and (2) can be realized.
(1) The insulation body 10 of the present embodiment having the first layer 10a and the second layer 10b as compared with the case where an insulation body composed of only the first layer 10a (hereinafter, referred to as a single-layer insulation body) is used. The operation time of the rocket motor 20 can be prolonged by using.
(2) The motor case 3 can be thermally protected by the insulation body 10 of the present embodiment which is thinner than the single-layer insulation body.

  Moreover, since a low-density resin is used as the material of the second layer 10b that increases the heat capacity, the lightweight insulation body 10 can reduce or delay the temperature rise of the motor case 3.

  The following [Table 1] shows the composition of the second layer 10b of the above-described embodiment and the layers of Reference Examples 1 to 3.

  In Table 1, EPDM represents ethylene-propylene-diene rubber, and NR represents natural rubber. In Table 1, the compounding ratio indicates the number of parts (per hundred rubber). That is, the compounding ratio indicates the ratio of the mass of each material when the total mass of the elastomer is 100.

  FIGS. 3A and 3B are graphs showing the densities and heat capacities (heat capacities per unit volume) of the second layer 10b of the embodiment and the layers of Reference Examples 1 to 3, respectively. In FIGS. 3A and 3B, the value in the case of the above-described first layer 10a is set as a reference (that is, 1). Each data of density and heat capacity in FIGS. 3A and 3B is for only one layer.

As shown in FIGS. 3A and 3B, the second layer 10b of the embodiment has a density as low as that of the layers of Reference Examples 1 and 2, and has a significantly larger heat capacity than Reference Examples 1 and 2. (Less than twice as much as Reference Example 1). Therefore, when achieving the same heat capacity as the layers of Reference Examples 1 and 2, the thickness of the second layer 10b of the embodiment can be reduced to about half of the thickness of the layers of Reference Examples 1 and 2.
Note that, in Reference Example 3 using alumina as the filler, the density is increased. As can be seen from FIGS. 3A and 3B, the second layer 10b using a resin as a filler can achieve both low density and high heat capacity. On the other hand, a hollow particle (Reference Example 2) or an alumina compound (Reference Example 3) generally used for heat insulation cannot achieve both low density and large heat capacity.

  FIG. 4A is a graph showing a heat transfer analysis result when a laminate in which two layers having the same thickness are laminated is attached to the inner wall surface 3 b of the motor case 3. Each data in FIG. 4A is, in order from the left side, when the laminated body is composed of two first layers 10a, when the laminated body is composed of the first layer 10a and the second layer 10b (that is, when the insulation body 10 In the case of the embodiment), when the laminate is composed of the first layer 10a and the layer of the reference example 1, when the laminate is composed of the first layer 10a and the layer of the reference example 2, the laminate is the first layer 10a and the reference example. 3 shows the case of three layers. Each laminate was attached to the inner wall surface 3b with the first layer 10a facing the internal space 3a. In the analysis of FIG. 4A, the thickness of each laminated body was made the same.

  The results in FIG. 4A are obtained by using the same heat transfer conditions for each laminate. That is, the heat transfer by the combustion gas (about 3500 ° C.) of the solid propellant and the radiant heating from the structural members inside the rocket motor, which became hot, were simulated for each laminate. The data of each of the laminates in FIG. 4 (A) is obtained after 320 seconds from the start of solid propellant combustion.

As shown in the graph of FIG. 4A, a laminate of two first layers 10a, a laminate of the first layer 10a and the layer of Reference Example 1, and a laminate of the first layer 10a and the layer of Reference Example 2 In the example, the temperature of the motor case 3 was 133 ° C. or higher, whereas in the example, the temperature of the motor case 3 was 121 ° C. That is, in the embodiment, the temperature rise of the motor case 3 can be suppressed.
In FIG. 4A, in the case of the laminated body of the first layer 10a and the reference example 3, although the temperature of the motor case 3 is lower than that of the example, the density of the layer of the reference example 3 It is larger than twice the density of the two layers 10b. Therefore, in consideration of the weight, the embodiment is more advantageous than the laminate of the first layer 10a and the reference example 3.

  FIG. 4B is a graph showing more detailed data of the heat transfer analysis result in each case in FIG. In FIG. 4B, the horizontal axis represents the time from the start of the combustion of the solid propellant, and the vertical axis represents the temperature of the motor case 3. In FIG. 4B, the broken line graph shows the case where the stacked body is made up of two first layers 10a, and the solid line graph shows the case where the stacked body is made up of the first layer 10a and the second layer 10b (that is, the embodiment). The dashed-dotted line indicates the case where the laminated body is composed of the first layer 10a and the layer of the reference example 1 or the case where the laminate is composed of the first layer 10a and the layer of the reference example 2 (graphs of these two cases). Are almost overlapped), and the two-dot chain line graph shows the case where the laminate is composed of the first layer 10a and the layer of Reference Example 3.

  As shown in the graph of FIG. 4B, in the embodiment, the temperature of the motor case 3 can be suppressed to 100 ° C. or less for about 150 seconds from the start of combustion. On the other hand, when only the first layer 10a is used and when the layers of Reference Examples 1 and 2 are used, the temperature of the motor case 3 is about 110 ° C. after 150 seconds have elapsed.

  The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made within the scope of the technical idea of the present invention. For example, any one of the following Modifications 1 to 3 may be employed alone, or two or more of Modifications 1 to 3 may be employed in any combination. In this case, the points not described below are the same as those described above.

(Modification 1)
FIG. 5 shows a two-stage thrust rocket motor 30 provided with the above-mentioned insulation body 10. The two-stage thrust rocket motor 30 includes a motor case 3, solid first and second propellants 5 a and 5 b, a partition 6, first and second ignition devices 7 a and 7 b, a nozzle 9, and an insulation body 10. Is provided.

  The partition wall 6 separates the internal space 3a of the motor case 3 into two spaces. The first and second propellants 5a and 5b are provided in two spaces separated by a partition 6, respectively. The first and second ignition devices 7a and 7b ignite the first and second propellants 5a and 5b, respectively. The first ignition device 7a ignites and burns one propellant 5a, and after a lapse of a set time after the completion of the combustion, the second ignition device 7b ignites the other propellant 5b and burns. Let it.

  The internal space 3a is heated to a high temperature (for example, 3000 ° C. or higher) for a long time including the set time and the combustion time of each of the propellants 5a and 5b. The above-mentioned insulation body 10 is also suitable for protecting the motor case 3 for this long time.

(Modification 2)
The insulation body 10 may be provided on an inner wall surface that covers an internal space in which combustion gas is generated or flows.

(Modification 3)
In the above-described embodiment, the insulation body 10 may or may not include a layer other than the first layer 10a and the second layer 10b. When the insulation body 10 includes a layer other than the first layer 10a and the second layer 10b, the positional relationship between the first layer 10a and the second layer 10b is the same as described above.

Reference Signs List 3 motor case, 3a internal space (combustion chamber), 3b inner wall surface, 5, 5a, 5b propellant, 6 partition, 7, 7a, 7b ignition device, 9 nozzle, 10 insulation body, 10a first layer, 10b 2 layers (heat storage layer forming body), 20,30 rocket motor

Claims (12)

An insulation body for providing on an inner wall surface that covers an internal space in which combustion gas is generated or flows,
A first layer, and a second layer disposed between the first layer and the inner wall surface,
The heat capacity per unit volume of the second layer is larger than the heat capacity per unit volume of the first layer, or the heat capacity of the entire second layer is larger than the heat capacity of the entire first layer. ,
The insulation body, wherein the second layer has an elastomer and a filler containing a resin that contributes to a heat capacity of the second layer .   The insulation body according to claim 1, wherein the second layer has a lower density than the first layer.   The insulation body according to claim 1, wherein the first layer has higher heat resistance than the second layer. The insulation body according to claim 1 , wherein the first layer has an elastomer and a filler that improves mechanical properties and heat resistance . The insulation body according to any one of claims 1 to 4, wherein the mass of the resin accounts for 50% or more of the total mass of the second layer. The filler of the first layer are aramid fibers, insulation body according to claim 4. The insulation body according to any one of claims 1 to 6, wherein the second layer includes, as the elastomer, ethylene-propylene-diene rubber and natural rubber.   A rocket motor comprising: a motor case in which a propellant is provided in an internal space; and the insulation body according to claim 1 provided on an inner wall surface of the motor case. A heat storage layer forming body for constituting an insulation body provided on an inner wall surface that covers an internal space in which combustion gas is generated or flows,
At the time of use, it becomes the second layer of the first layer and the second layer of the insulation body, and is disposed between the first layer and the inner wall surface,
The heat capacity per unit volume is larger than the heat capacity per unit volume of the first layer, or the total heat capacity is larger than the total heat capacity of the first layer,
The heat storage layer forming body , wherein the second layer has an elastomer and a filler containing a resin that contributes to a heat capacity of the second layer . A method for producing an insulation body for providing on an inner wall surface that covers an internal space in which combustion gas is generated or flows,
(A) a first composition is produced by mixing an elastomer, a first filler, and an additive;
(B) forming a first layer sheet by forming the first composition into a sheet shape;
(C) a second composition is produced by mixing an elastomer, a second filler containing a resin, and an additive,
(D) forming a second composition into a sheet to form a second layer sheet, wherein the resin contributes to the heat capacity of the second layer sheet;
(E) A method for manufacturing an insulation body, wherein an insulation body is obtained by laminating a first layer sheet and a second layer sheet on each other. The method for producing an insulation body according to claim 10, wherein the mass of the resin accounts for 50% or more of the total mass of the second layer sheet. The method for producing an insulation body according to claim 10 or 11, wherein an ethylene-propylene-diene rubber and a natural rubber are used as the elastomer.

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