JP2019142049A - Manufacturing method of thermoplastic resin filler blending rubber, and manufacturing method of rocket motor - Google Patents

Abstract

To provide a manufacturing method of thermoplastic resin filler blending rubber with which a heat-insulating property is improved by enhancing dispersibility of a resin filler, and to stably provide a manufacturing method of a rocket motor with which the heat-insulating property gives higher performance than that of conventional rocket motors by forming a high heat-insulating layer.SOLUTION: The method includes a kneading step S2 of kneading a thermoplastic resin filler 2 in rubber 4. According to the kneading step S2, the thermoplastic resin filler 2 and the rubber 4 are kneaded while keeping a surface temperature of the rubber 4 at 60°C or less. The rubber 4 comprises solid rubber 4A that is solid at normal temperature, and liquid rubber 4B that is liquid or starch sirup-shaped rubber at the normal temperature. The liquid rubber 4B and the thermoplastic resin filler 2 are kneaded to manufacture composition rubber 4C. Next, the composition rubber 4C and the solid rubber 4A are kneaded.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a thermoplastic resin filler-containing rubber that suppresses heat transfer from a high-temperature combustion gas and a method for producing a rocket motor.

  The rocket motor generates and ejects a combustion gas of solid propellant, and propels the rocket by the ejected combustion gas. Such rocket motors are widely used as defense rockets, missiles, artificial satellite launch rocket propulsion engines, observation rockets, attitude control rockets, and the like.

  The rocket motor has a motor case having an internal space in which a solid propellant is provided. Solid propellants generate high-temperature and high-pressure combustion gases when ignited. This combustion gas is ejected to the outside from a nozzle provided in the motor case.

The space where the combustion gas is generated or flows becomes a high temperature (for example, 1000 ° C. or more or 3000 ° C. or more). Therefore, in order to suppress heat transfer from the combustion gas to the motor case and to thermally protect the inner wall surface, it is necessary to provide a heat insulating layer such as an insulation between the motor case and the solid propellant.
Such a heat insulating layer of a rocket motor is disclosed in, for example, Patent Document 1.
Further, a conventional rubber manufacturing method is disclosed in, for example, Patent Document 2.

JP 2011-38456 A JP-A-11-116693

In order to improve the performance of the rocket motor, it is necessary to delay as much as possible the high heat generated by the combustion of the solid propellant from conducting to the motor case, or to reduce the heat capacity conducted to the motor case.
In general, a material that easily conducts heat has a small heat capacity and a low specific heat. In other words, a material with a low specific heat has a low heat capacity that can be stored in itself, so that the heat capacity conducted to the opposite side across the material is high. The main material of the heat insulation layer is rubber. Therefore, in order to improve the performance of the rocket motor, it is necessary to form a heat insulating layer having a specific heat higher than that of the conventional heat insulating layer.

For example, it is conceivable to obtain a heat insulating layer having a higher specific heat than a conventional rubber mixture having a low resin filler content by kneading as much of the resin filler having a high specific heat as possible to the rubber constituting the heat insulating layer. In general, it is considered that the resin filler is improved in dispersibility by increasing the kneader filling rate and the rotational speed and kneading vigorously. Moreover, it can be expected that the heat insulating property of the heat insulating layer is improved as the amount of the resin filler is increased and the resin filler is uniformly dispersed. The resin filler is a spherical particle such as polyamide.
However, in practice, when the proportion of the resin filler is increased by the conventional mixing method, the resin filler forms agglomerates, resulting in poor dispersion, and as a result, the specific heat of the heat insulating layer decreases. The resin filler is a particle having a diameter of 10 μm to 13 μm, but the diameter becomes 2 to 3 mm or more when agglomerated. Since the agglomerated resin filler is not uniformly dispersed in the rubber, the heat insulating property of the molded rubber mixture is eventually lowered. Therefore, in the conventional mixing method, it has not been possible to increase the specific heat of the heat insulating layer simply by increasing the proportion of the resin filler.

  The present invention has been developed to solve the above-described problems. That is, a first object of the present invention is to provide a method for producing a thermoplastic resin filler-containing rubber that improves the heat insulation by increasing the dispersibility of the resin filler. A second object of the present invention is to stably provide a method for manufacturing a rocket motor that has higher performance than conventional rocket motors by forming a heat insulating layer having high heat insulating properties.

According to the present invention, the method includes a kneading step of kneading a thermoplastic resin filler into a rubber that is a mixture of a solid rubber that is solid at room temperature and a liquid rubber or syrup-like liquid rubber at room temperature,
The kneading step includes
(A) a pre-kneading step for producing a composition rubber by kneading the liquid rubber and the thermoplastic resin filler;
(B) and then a main kneading step of kneading the composition rubber and the solid rubber,
In the kneading step, there is provided a method for producing a thermoplastic resin filler-containing rubber in which the surface temperature of the rubber is maintained at 60 ° C. or less and the thermoplastic resin filler and the rubber are kneaded.

According to the present invention, a thermoplastic resin filler-containing rubber produced by the above-described method for producing a thermoplastic resin filler-containing rubber,
Insulation containing reinforcing fibers;
A motor case having an internal space;
A solid propellant that generates combustion gas, and
The thermoplastic resin filler compounded rubber and the insulation are layered to form a heat insulating layer,
Covering the inner wall surface of the motor case with the heat-insulating layer so that the thermoplastic resin filler-containing rubber is located radially outside the motor case with respect to the insulation,
A method for manufacturing a rocket motor is provided, in which the solid propellant is provided in the internal space radially inside the motor case with respect to the heat insulating layer.

According to the above-described present invention, since the raw rubber and the thermoplastic resin filler are kneaded while maintaining the surface temperature at 60 ° C. or lower, the thermoplastic resin filler is kneaded with the rubber while keeping the thermoplastic resin fillers hardly sticking to each other. be able to. Therefore, it can suppress that a thermoplastic resin filler forms agglomeration.
Therefore, since the thermoplastic resin filler can be uniformly dispersed in the thermoplastic resin filler-containing rubber, the heat insulating property of the thermoplastic resin filler-containing rubber can be improved as compared with the conventional rubber mixture.

  Moreover, since a thermoplastic resin filler compounded rubber with high heat insulation can be obtained, a heat insulation layer with high heat insulation can be manufactured. Thereby, a rocket motor having higher performance than the conventional rocket motor can be manufactured stably.

It is explanatory drawing of the manufacturing method of the compounded rubber of this embodiment, and the conventional mixing method. It is a flowchart of the manufacturing method of the compounded rubber of this embodiment. It is an external appearance photograph of the conventional rubber mixture and the compounded rubber of this embodiment. It is explanatory drawing of the rocket motor manufactured with the manufacturing method of the rocket motor of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

The inventors of the present invention have found that the resin filler 2 becomes agglomerated when the surface temperature of the rubber 4 to be kneaded becomes higher than 60 ° C.
Accordingly, the inventors of the present invention invented a method for producing a thermoplastic resin filler-containing rubber 1 (hereinafter referred to as “rubber 1”) based on this discovery.

The compounded rubber 1 has a rubber 4 and a thermoplastic resin filler 2 (hereinafter, resin filler 2). The rubber 4 preferably includes a solid rubber 4A that is solid at room temperature and a liquid rubber or water-like liquid rubber 4B that is liquid at room temperature. The liquid rubber 4B accounts for 3 to 6% of the weight of the compounded rubber 1, and preferably 5%. The resin filler 2 occupies 40 to 60% of the volume of the compounded rubber 1, and preferably 50%.
The compounded rubber 1 includes a resin filler 2 in a rubber 4 that is a base material. The rubber 4 includes the resin filler 2 inside by being kneaded with the resin filler 2.

The rubber 4 is a mixture of solid rubber 4A and liquid rubber 4B. The rubber 4 may be natural rubber, synthetic rubber, or a mixture of both.
For example, the solid rubber 4A is a vulcanizable solid rubber. As a solid rubber 4A, a third component such as 5-ethylidene-2-norbornene, 1,4-hexadiene, or dicyclopentadiene was added to a copolymer of ethylene and propylene (EPM) and bonded as a side chain. Ethylene-propylene rubber may be used. For example, the solid rubber 4A is preferably ethylene-propylene-diene rubber (EPDM).

Alternatively, the solid rubber 4A may be natural rubber (hereinafter referred to as NR) or isoprene rubber (hereinafter referred to as IR) having a polyisoprene structure, or acrylonitrile butadiene rubber (hereinafter referred to as NBR) which is a copolymer of acrylonitrile and butadiene.
Further, the solid rubber 4A of the present embodiment may be used in combination of these plural types, or may be used alone.

The liquid rubber 4B is a liquid or water-like rubber that is fluid at room temperature. Liquid rubber 4B includes liquid butadiene rubber (hereinafter referred to as BR) (1,2-BR, 1,4-BR), liquid IR (1,4-IR), liquid NBR rubber, and liquid butadiene styrene rubber (hereinafter referred to as SBR). Liquid polybutene and liquid urethane rubber are preferred. The liquid rubber 4B may be used by combining a plurality of types of these, or may be used alone.
The compounded rubber 1 may contain additives such as carbon black, softener, plasticizer, anti-aging agent, processing aid, and tackifier. Further, a vulcanizing agent and a vulcanization accelerator used for vulcanizing the solid rubber 4A and the liquid rubber 4B may be included.

  The resin filler 2 is a thermoplastic resin particle, for example, a spherical particle such as polyamide. The size of the particles is preferably 10 μm to 13 μm in diameter. However, the present invention is not limited to this, and the size of the resin filler 2 particles may be larger or smaller.

Since the resin filler 2 is a spherical particle, it is possible to prevent voids from being formed inside the compounded rubber 1. Thereby, it can prevent that the heat capacity of the compounded rubber 1 falls by a space | gap.
The compounded rubber 1 can be used for various purposes as a heat insulating material in addition to the rocket motor 8 described later.

The present invention is a method for producing the compounded rubber 1.
FIG. 1 is an explanatory diagram of a method for producing the compounded rubber 1 of the present embodiment and a conventional mixing method. FIG. 1 (A) is an explanatory view of a conventional mixing method, and FIG. 1 (B) is an explanatory view of a manufacturing method of the compounded rubber 1 of this embodiment.
FIG. 2 is a flowchart of the manufacturing method of the compounded rubber 1 of the present embodiment.

As shown in FIG. 1A, when the proportion of the resin filler 2 is simply increased by the conventional mixing method, the resin filler 2 is softened and agglomerated.
Therefore, as shown in FIG. 1 (B) and FIG. 2, it is necessary to manufacture the compound rubber 1 by the method for manufacturing the compound rubber 1 of the present embodiment.

The manufacturing method of the compounded rubber 1 of the present embodiment includes a compounding step S1, a kneading step S2, a vulcanizing and kneading step S3, and a molding step S4.
For the production of the compounded rubber 1 of the present embodiment, the rubber 4, the resin filler 2, and the above-described additives and vulcanizing agents are used.

In the blending step S1, the rubber 4 as the raw rubber is selected, and the types and amounts of various additives and resin fillers 2 are determined.
The kneading step S2 is a step of kneading the resin filler 2 with the rubber 4, and is divided into, for example, a preliminary kneading step S2a and a main kneading step S2b. Kneading is mixing the resin filler 2 and the additive with the rubber 4 and applying mechanical shearing force to impart plasticity to the rubber 4 and simultaneously dispersing the resin filler 2 and the additive in the rubber. In the manufacturing method of the compounded rubber 1 of the present embodiment, the surface temperature of the rubber 4 being kneaded is kept at 60 ° C. or lower throughout the kneading step S2. In general, the surface temperature of the rubber 4 during the kneading step S2 tends to rise from room temperature due to shear during kneading.

  The inventor of the present invention clarified that the agglomeration of the resin filler 2 and poor dispersion is caused by kneading at a temperature higher than 60 ° C. When a large amount of the resin filler 2 is kneaded with the rubber 4, friction heat is generated by friction between the resin fillers, and the rubber mixture becomes high temperature. For example, the melting point of polyamide, which is an example of the resin filler 2, is 176 ° C. to 265 ° C. Even if it is much lower than the melting point, if it exceeds 60 ° C., it is considered that the resin filler 2 softens and tends to adhere to each other. .

  Therefore, in the manufacturing method of the compounded rubber 1 of this embodiment, it is necessary to knead | mix, keeping the surface temperature of the rubber 4 at 60 degrees C or less in the kneading | mixing process S2. Generally, in a kneader or other kneader, the temperature at which the surface temperature of the rubber 4 being kneaded can be measured by measuring the temperature of the inner wall in order to know the internal material temperature and manage the kneading state. A total is installed. In the kneading step S2, the rubber 4 and the resin filler 2 are kneaded while measuring the surface temperature of the rubber 4 with this thermometer.

  The method for controlling the surface temperature of the rubber 4 includes, for example, adjusting the rotational speed and rotational speed of the kneader to suppress the generation of frictional heat, increasing / decreasing the amount of raw materials to be put into the kneader, and gradually increasing the resin filler 2 in small steps. It may be done by putting Alternatively, the rotation of the kneader may be stopped or the kneader may be cooled when the surface temperature of the rubber 4 rises.

  In the preliminary kneading step S2a, first, the resin filler 2 is added to the liquid rubber 4B and kneaded to produce the composition rubber 4C. By this process, the resin filler 2 can be spread over the liquid rubber 4B and the resin filler 2 can be dispersed. The liquid rubber 4 </ b> B has a role as a dispersant for the resin filler 2. In addition, since the resin filler 2 is coated with the liquid rubber 4B, friction between the resin fillers can be suppressed, and generation of frictional heat can be further suppressed.

In the main kneading step S2b, for example, the solid rubber 4A is added to the composition rubber 4C having undergone the preliminary kneading step S2a and kneaded. The kneading may be performed with a Banbury mixer or the like.
In addition, in order to improve the plasticity and fluidity of the solid rubber 4A, the solid rubber 4A may be masticated before the preliminary kneading step S2a.

Subsequently, vulcanization kneading process S3 is performed.
The vulcanization kneading step S3 is a step of adding a solid additive or a vulcanizing agent, applying heat thereto, and kneading using an open roll.
In this vulcanization kneading step S3, temperature control for the purpose of dispersing the resin filler 2 is not performed. Before the vulcanization kneading step S3 (main kneading step S2b), the resin filler 2 is sufficiently dispersed, and once dispersed in the rubber, it does not soften or agglomerate. This is because there is no problem even if the temperature is 60 ° C. or higher.
In addition, the temperature control in the category performed not for the dispersion | distribution of the resin filler 2 but in order to prevent deterioration of rubber | gum is performed similarly to the past.

Thereafter, a molding step S4 is performed.
The molding step S4 is a step of molding the vulcanized compounded rubber 1. For example, when manufacturing the heat insulation layer 11 used for the rocket motor 8, the compounded rubber 1 that has undergone the kneading step S2 or the vulcanization kneading step S3 is rolled into a sheet. For example, the compounded rubber 1 may be formed into a sheet by passing it through a calender roll machine.

Thus, since the manufacturing method of this embodiment knead | mixes the rubber 4 and the resin filler 2 while maintaining the surface temperature of the rubber 4 at 60 ° C. or less at which the resin filler 2 does not exhibit the property of adhering to each other, Formation of agglomerates can be suppressed.
Accordingly, since the resin filler 2 can be uniformly dispersed in the compounded rubber, the heat insulating property of the compounded rubber 1 can be improved as compared with the conventional rubber mixture.

For example, when the resin filler 2 is directly put into the solid rubber 4A, a strong force is applied to the resin filler 2, so that the resin filler 2 is pressed and hardened to generate a large amount of agglomerates.
However, in the manufacturing method of the present embodiment, the resin filler 2 is put in the dispersant (liquid rubber 4B) and dispersed before the resin filler 2 is agglomerated as described above, and then kneaded with the solid rubber 4A. It is difficult to agglomerate the resin filler 2. By putting the resin filler 2 in the liquid rubber 4B and then kneading with the solid rubber 4A, the resin filler 2 can be dispersed in the liquid rubber first, and the resin filler 2 is uniformly dispersed in the compounded rubber. be able to.
Therefore, by using the manufacturing method of the compounded rubber 1 of the present embodiment, even if more resin filler 2 is added to the rubber 4, it can be uniformly dispersed, so that the specific heat is higher and higher than the conventional rubber mixture. The compounded rubber 1 having heat insulation properties can be obtained.

(Example)
FIG. 3 is an appearance photograph of a conventional rubber mixture and the compounded rubber 1 of the present embodiment.
FIG. 3A is an external view photograph of a rubber sheet of a conventional rubber mixture. This rubber mixture is manufactured by performing the kneading step S2 without temperature control.
On the other hand, FIG. 3 (B) is an appearance photograph of the rubber sheet of the compounded rubber 1 of the present embodiment. This compounded rubber 1 is manufactured by controlling the surface temperature of the rubber 4 to 60 ° C. or less in the kneading step S2 by the above-described method for manufacturing the compounded rubber 1 of the present embodiment.

Specifically, the rubber surface temperature during kneading of the rubber sheet of FIG. On the other hand, the rubber surface temperature at the time of kneading the rubber sheet of the compounded rubber 1 of the present embodiment in FIG.
In this example, the compounding amount of the resin filler 2 of the conventional rubber mixture (FIG. 3A) and the compounded rubber 1 of the present embodiment (FIG. 3B) is the same.
The white spots in FIGS. 3A and 3B represent the agglomerated resin filler 2.

  As can be seen from this figure, many agglomerates (white spots) of various sizes of the resin filler 2 are scattered in the rubber sheet of FIG. This indicates that the compounded rubber 1 causes agglomeration of the resin filler 2 and causes poor dispersion.

On the other hand, the agglomeration (white spots) of the resin filler 2 is hardly seen in the compounded rubber 1 manufactured by the manufacturing method of the present embodiment.
As described above, when the rubber 4 and the resin filler 2 are kneaded, the surface temperature of the rubber 4 is controlled to 60 ° C. or less to suppress the agglomeration of the resin filler 2, and the resin is contained in the compounded rubber. It became clear that the filler 2 can be uniformly dispersed.

FIG. 4 is an explanatory diagram of the rocket motor 8 manufactured by the method for manufacturing the rocket motor 8 of the present embodiment. 4A is a longitudinal sectional view of the rocket motor 8, and FIG. 4B is an enlarged view of a portion P in FIG. 4A.
The rocket motor 8 generates and ejects the combustion gas of the solid propellant 7, propels the rocket with the ejected combustion gas, and changes its posture. Such a rocket motor 8 is widely used as a defense rocket, missile, artificial satellite launch rocket propulsion engine, observation rocket or attitude control rocket.

In this figure, the rocket motor 8 includes a motor case 6, a solid propellant 7, a heat insulating layer 11, an ignition device 12, and a nozzle 13.
The motor case 6 is a container having an internal space 5.
The solid propellant 7 is accommodated in the internal space 5 of the motor case 6 and generates high-temperature and high-pressure combustion gas when ignited. When the ignition device 12 ignites the solid propellant 7, the combustion gas is ejected from the nozzle 13 provided in the motor case 6 to the outside.

The heat insulation layer 11 of this embodiment is located between the motor case 6 and the solid propellant 7, and is provided in a sheet shape on the inner wall surface 6a of the motor case 6 as shown in FIG. The heat insulating layer 11 is provided to protect the motor case 6 from the high temperature (in the example, about 3000 ° C.) of the internal space 5 due to the combustion of the solid propellant 7.
The heat insulating layer 11 includes the compounded rubber 1 and the insulation 9. The compound rubber 1 is provided on the inner wall surface side (radially outward) of the motor case 6, and the insulation 9 is provided on the solid propellant side (radially inner side of the motor case 6).

Since the compounded rubber 1 is manufactured by the above-described manufacturing method, as shown in FIG. Therefore, since the compounded rubber 1 has a higher specific heat than a conventional rubber mixture and becomes a heat sink, it exhibits higher heat insulation than a conventional rubber mixture.
The compound rubber 1 is provided in a sheet shape and covers the inner wall surface 6 a of the motor case 6. Since the compounded rubber 1 has the resin filler 2, it has a larger heat capacity than the insulation 9 that does not include the resin filler 2. This means that the heat capacity of at least one of the unit volume and the whole is larger in the resin filler 2 than in the insulation 9. The compounded rubber 1 is configured to have a density lower than that of the insulation 9.
Further, as described above, since the resin filler 2 is a spherical particle, the compounded rubber 1 has no voids inside. Thereby, it can prevent that the heat capacity of compounded rubber 1 falls by a gap.

  The insulation 9 covers the inner wall surface 6 a of the motor case 6 and is located between the compounded rubber 1 and the solid propellant 7. Specifically, the insulation 9 further covers the compounded rubber 1 covering the inner wall surface 6 a of the motor case 6. The insulation 9 is a rubber material containing reinforcing fibers such as aramid fibers.

As shown in FIG. 4B, the rocket motor 8 has two types of heat insulating layers 11 of insulation 9 and compounded rubber 1 for heat insulation. The heat insulation layer 11 is scraped by the flow of combustion gas. Insulation 9 contains strong fibers such as aramid fibers, but not in compounded rubber 1. Therefore, since the compounded rubber 1 is easily scraped by the flow of the combustion gas, it is not suitable for constituting the surface of the heat insulating layer 11 exposed to the combustion gas.
On the other hand, since the heat capacity that the insulation 9 can store in itself is smaller than that of the compounded rubber 1, if the heat insulating layer 11 is formed only by the insulation 9, the heat insulating layer 11 must be thickened. Accordingly, the rocket motor 8 becomes heavier, and the performance of the rocket motor 8 as a whole decreases.

As described above, the compounded rubber 1 produced by the method for producing the compounded rubber 1 of the present embodiment has a higher specific heat than a conventional rubber mixture and has a high heat insulating property. This is because the compounded rubber 1 is a rubber material having a high specific heat, and therefore has a high heat capacity for storing heat. Therefore, the compounded rubber 1 becomes a heat storage layer, and the heat conduction 14 to the motor case 6 is delayed. That is, the compounded rubber 1 becomes a heat sink, and heat is hardly transmitted to the motor case 6. Thus, the heat insulation of the heat insulation layer 11 can be improved by using the compounded rubber 1 with high heat insulation for the heat insulation layer 11.
Therefore, in order to manufacture a high-performance rocket motor 8, while using a tough insulation 9 on the surface of the heat insulating layer 11 exposed to the combustion gas as in the configuration of the rocket motor 8 of this embodiment, It is necessary to use compounded rubber 1 having a high specific heat. The inner side is the outer side in the radial direction of the motor case 6 than the insulation 9.

As a result, the rocket motor 8 of the present embodiment maintains the toughness of the heat insulating layer 11 with the insulation 9 and uses the compounded rubber 1 having a high specific heat to provide the necessary heat insulating properties even if the heat insulating layer 11 is thinned. Can be acquired. Therefore, the rocket motor 8 can be manufactured lighter than the conventional rocket motor. Alternatively, since the necessary heat insulating property can be obtained even if it is thinner than the conventional heat insulating layer, the amount of the solid propellant 7 packed in the motor case 6 can be increased.
Thus, by using the compounded rubber 1 for the heat insulation layer 11, the performance of the rocket motor 8 can be improved as compared with the conventional rocket motor.

Next, the manufacturing method of the rocket motor 8 of this embodiment is demonstrated.
First, the above-described compounded rubber 1, insulation 9, motor case 6, and solid propellant 7 are prepared. The compound rubber 1 and the insulation 9 are formed into a sheet shape.
Next, the inner wall surface 6 a of the motor case 6 is covered with the compound rubber 1. Further, the compounded rubber 1 covering the inner wall surface 6 a of the motor case 6 is further covered with the insulation 9.
Thereafter, the solid propellant 7 is provided inside the insulation 9 (in the radial direction of the motor case 6).
Thereby, the rocket motor 8 mentioned above can be manufactured.

  Alternatively, the heat insulating layer 11 may be formed of the compound rubber 1 and the insulation 9 before the compound rubber 1 and the insulation 9 are put in the internal space 5 of the motor case 6. In this case, the heat-insulating layer 11 is formed by laminating the compounded rubber 1 and the insulation 9 in layers. Thereby, the heat insulation layer 11 becomes a two-layer structure of the compounded rubber 1 and the insulation 9.

Next, the inner space 5 is covered with a heat insulating layer 11 so that the compounded rubber 1 is positioned on the outer side in the radial direction of the motor case 6 with respect to the insulation 9, and the inner space 5 on the inner side in the radial direction of the motor case 6 with respect to the heat insulating layer 11. A solid propellant 7 is provided.
Also by this method, the rocket motor 8 described above can be manufactured.

In the manufacturing method of the rocket motor 8 of the present embodiment, the heat insulating layer 11 formed of the compound rubber 1 can be provided between the solid propellant 7 and the motor case 6.
Therefore, the compound rubber 1 becomes a heat sink, and the motor case 6 can be protected from the high heat of the combustion gas. Thus, since the compounded rubber 1 having a high specific heat can be stably obtained, the high-performance rocket motor 8 can be stably produced.

According to the present invention described above, since the raw rubber 4 and the thermoplastic resin filler 2 are kneaded while maintaining the surface temperature at 60 ° C. or lower, the rubber is maintained while the thermoplastic resin fillers are hardly adhered to each other. 4 can be kneaded. Therefore, it can suppress that the thermoplastic resin filler 2 forms agglomeration.
Accordingly, since the thermoplastic resin filler 2 can be uniformly dispersed in the thermoplastic resin filler-containing rubber, the heat insulating property of the thermoplastic resin filler-containing rubber 1 can be improved as compared with the conventional rubber mixture.

  Moreover, since the compounded rubber 1 with high heat insulation can be obtained, the heat insulation layer 11 with high heat insulation can be manufactured. The rocket motor 8 with higher performance than the conventional rocket motor can be manufactured stably.

1 Thermoplastic resin filler compound rubber (compound rubber),
2 thermoplastic resin filler (resin filler),
4 rubber, 4A solid rubber,
4B liquid rubber, 4C composition rubber,
5 Internal space, 6 Motor case,
6a inner wall surface, 7 solid propellant,
8 rocket motors, 9 insulation,
11 thermal insulation layer, 12 ignition device, 13 nozzle,
14 heat conduction, S1 blending process,
S2 kneading step, S2a preliminary kneading step, S2b main kneading step,
S3 vulcanization and kneading process, S4 molding process

Claims (3)

Including a kneading step of kneading a thermoplastic resin filler into a rubber which is a mixture of a solid rubber which is solid at normal temperature and a liquid rubber or water-like liquid rubber at normal temperature,
The kneading step includes
(A) a pre-kneading step for producing a composition rubber by kneading the liquid rubber and the thermoplastic resin filler;
(B) and then a main kneading step of kneading the composition rubber and the solid rubber,
A method for producing a thermoplastic resin filler-containing rubber, wherein in the kneading step, a thermoplastic resin filler and rubber are kneaded while maintaining a surface temperature of the rubber at 60 ° C. or lower.   The method for producing a thermoplastic resin filler-containing rubber according to claim 1, wherein the thermoplastic resin filler is polyamide particles. A thermoplastic resin filler-containing rubber produced by the method for producing a thermoplastic resin filler-containing rubber according to claim 1;
Insulation containing reinforcing fibers;
A motor case having an internal space;
A solid propellant that generates combustion gas, and
The thermoplastic resin filler compounded rubber and the insulation are layered to form a heat insulating layer,
Covering the inner wall surface of the motor case with the heat-insulating layer so that the thermoplastic resin filler-containing rubber is located radially outside the motor case with respect to the insulation,
A method for manufacturing a rocket motor, wherein the solid propellant is provided in the internal space radially inside the motor case with respect to the heat insulating layer.