KR20210155887A - Manufacturing method of composite for solid propellant and composite for solid propellant by the method - Google Patents

Abstract

The present invention relates to a method for preparing a solid propellant composition and a solid propellant composition prepared by the same method. According to the method, raw materials for preparing a solid propellant are divided and injected into a vacuum mixer, and a vacuum mixing process is performed between each injection step. A curing agent is injected last among the raw materials, and then the final vacuum mixing process is performed to lower the viscosity of the propellant so that defects such as pores or cracks inside the manufactured solid propellant are prevented, and the quality of the solid propellant is improved. The method enables stable solid propellant operation by preventing rocket explosion accidents caused by defects such as pores or cracks in the solid propellant and increases the mixing efficiency of the solid propellant. Thus, the mechanical properties of the propellant are also increased due to this improved viscosity.

Description

Method for preparing a solid propellant composition and a solid propellant composition prepared by the method

The present invention relates to a method for preparing a solid propellant composition and to a solid propellant composition prepared by the method.

Solid propellants have advantages over liquid fuels in that they can be stored for a long time and can be fired immediately. Therefore, it is used for military rockets, missiles, or space launch vehicles, and is also used as an auxiliary fuel for liquid fuel.

The HTPB/AP-based solid propellant is cast in the combustion tube of the propulsion engine to have a grain of a desired shape after the raw material mixing process is completed. A cast propellant is made into a solid propellant by curing at a specified temperature for a certain period of time.

At this time, if defects such as pores or cracks exist inside the propellant grains, an explosion accident may occur due to an unwanted increase in the combustion area.

Therefore, after the mixing of the propellant is finished, it is advantageous to make the viscosity of the propellant low in order to prevent such defects and to ensure smooth casting in the casting process.

The binder added to the premix when preparing the solid propellant is a polymer material having a hydroxyl group (-OH), and a curing catalyst that activates the hydroxyl group together with the binder to promote chemical reaction is generally added.

However, when a curing catalyst is first added in the premix when manufacturing a solid propellant, the viscosity increase of the propellant rapidly increases after the curing agent is added due to the activated binder, so there are many difficulties when injecting the propellant raw material into the propulsion engine.

In addition, in the conventional manufacturing method of the solid propellant, the solid raw material is not properly dispersed in the premix and agglomerated when the solid raw material is input because the vacuum mixing process is performed after all the solid raw material is input. Due to this, there was a great difficulty in the mixing process, such as a large pressure was generated on the mixer blades and the mixer stopped.

A propellant composition with high viscosity has a difficult raw material mixing and injection process, and the possibility of defects such as pores or cracks inside the propellant grains is high. There was a problem that an explosion accident occurred.

0001) Korean Patent Registration No. 1850395 "Solid propellant composition and manufacturing method of solid propellant composition using same" (Registered on April 13, 2018)

It is an object of the present invention to provide a method for preparing a solid propellant composition that also lowers the viscosity of a propellant composition for preparing a solid main agent by controlling the timing of adding a curing agent and a curing catalyst, and a solid propellant composition prepared by the method do.

In order to achieve the above object, an embodiment of the method for producing a solid propellant according to the present invention is a method for producing a solid propellant composition for producing a solid propellant, a premix step of injecting a binder raw material into a vacuum mixer, a curing agent A first solid raw material injection step of injecting a part of the solid raw material of the solid propellant composition except for the vacuum blender into the vacuum mixer, a first vacuum blending step of vacuum mixing a part of the binder raw material and the solid raw material, and the curing agent after the first vacuum blending step A second solid raw material injection step of injecting the remainder of the solid raw material of the solid propellant composition except for the vacuum mixer into the vacuum mixer, a second vacuum blending step of vacuum mixing the binder raw material and the solid raw material after the second solid raw material injection step, the second After the vacuum mixing step, a curing agent injection step of injecting a curing agent into the vacuum mixer, and a third vacuum mixing step of vacuum mixing the binder raw material, the solid raw material, and the curing agent after the curing agent injection step.

In the present invention, the solid raw material may include an oxidizing agent and a metal fuel.

In the present invention, in the first solid raw material injection step, 45 wt% to 55 wt% of the total weight of the solid raw material may be injected into a vacuum mixer and stirred.

In the present invention, the internal temperature of the vacuum mixer may be maintained at 55°C to 65°C in the premixing step, the first solid raw material injection step, and the first vacuum mixing step.

In the present invention, the first solid raw material injection step may inject the solid raw material into the vacuum mixer at an injection rate of 45 kg/min to 55 kg/min.

In the present invention, in the first solid raw material injection step, a solid raw material having particles larger than a predetermined particle size among solid raw materials is injected using a screw feeder at an injection rate of 45 kg/min to 55 kg/min, and the screw feeder is 2 It is possible to inject solid raw materials into the vacuum mixer at an injection rate of 45kg/min to 55kg/min while repeating operation for ~6 seconds and stopping for 20~30 seconds.

In the present invention, in the second solid raw material injection step, 45 wt% to 55 wt% of the total weight of the solid raw material may be injected into the vacuum mixer.

In the present invention, in the second solid raw material injection step, the internal temperature of the vacuum mixer may be maintained at 55°C to 65°C.

In the present invention, in the second solid raw material injection step, the solid raw material may be injected into the vacuum mixer at an injection rate of 10 kg/min to 20 kg/min and stirred.

In the present invention, in the second solid raw material injection step, a solid raw material having particles smaller than a predetermined particle size among solid raw materials may be injected using a screw feeder at an injection rate of 10 kg/min to 20 kg/min.

In the second solid raw material injection step of the present invention, the screw feeder operates for 2 to 6 seconds and stops for 25 to 35 seconds while repeating the solid raw material into the vacuum mixer at an injection rate of 10 kg/min to 20 kg/min. can be injected.

In the present invention, in the curing agent injection step, 1% to 15% by weight of the curing agent may be injected with respect to the total weight of the solid propellant composition, and a curing catalyst may be further injected.

In the present invention, the curing agent injection step may be performed by injecting a curing agent and a curing catalyst while maintaining the internal temperature of the vacuum mixer at 45° C. to 54° C. and stirring.

In the present invention, in the third vacuum mixing step, the solid propellant composition may be vacuum mixed in a state in which the internal temperature of the vacuum mixer is maintained at 45° C. to 54° C.

According to the present invention, raw materials for producing solid propellants are divided and injected into a vacuum mixer, and a vacuum mixing process is performed between each injection step, and the curing agent is injected last among the raw materials and then the final vacuum mixing process is performed to lower the viscosity of the propellant. It has the effect of preventing the occurrence of defects such as pores or cracks inside the solid propellant and improving the quality of the solid propellant.

The present invention enables stable solid propellant operation by preventing rocket explosion accidents due to defects such as pores or cracks in solid propellant, increases the mixing efficiency of solid propellant, and increases the mechanical properties of the propellant due to this improved viscosity It works.

1 is a process diagram illustrating an embodiment of a method for preparing a solid propellant composition according to the present invention.
2 is a photograph of a solid propellant composition prepared as a comparative example and a solid propellant composition prepared as an example of the present invention in the method for preparing a solid propellant composition according to the present invention.
3 is a graph showing the viscosity of the solid propellant composition prepared as a comparative example and the solid propellant composition prepared as an example of the present invention after the curing agent is added in the method for preparing the solid propellant composition according to the present invention.
4 is a graph showing the mechanical properties of the solid propellant prepared with the solid propellant composition of Comparative Example and the solid propellant prepared with the solid propellant composition of Examples in the method for preparing the solid propellant composition according to the present invention.

Hereinafter, the present invention will be described in more detail.

A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings as follows. Prior to the detailed description of the present invention, the terms or words used in the present specification and claims described below should not be construed as being limited to conventional or dictionary meanings. Therefore, the configuration shown in the embodiments and drawings described in the present specification is only the most preferred embodiment of the present invention and does not represent all of the technical spirit of the present invention, so at the time of the present application, various It should be understood that there may be equivalents and variations.

1 is a process diagram illustrating an embodiment of a method for manufacturing a solid propellant composition according to the present invention, and with reference to FIG. 1, an embodiment of a method for manufacturing a solid propellant composition according to the present invention is detailed below. explain in detail.

An embodiment of the method for producing a solid propellant composition according to the present invention is to prepare an HTPB/AP-based solid propellant, and mix raw materials such as a binder, a curing agent, an oxidizing agent, a plasticizer, and a binder to obtain an HTPB/AP-based solid propellant. A method for preparing a solid propellant composition for preparing a solid propellant.

The solid propellant composition comprises 1 wt% to 20 wt% of a binder comprising a hydroxyl terminated polymer, 1 wt% to 15 wt% of a curing agent comprising an isocyanate-based compound, and a perchlorate compound, based on the total weight 60 wt% to 70 wt% of an oxidizing agent, 1 wt% to 10 wt% of a plasticizer comprising an ester-based compound, and 0.1 wt% to a binder comprising an amine-based compound, an aziridine-based compound, an amide-based compound, or a combination thereof It is taken as an example to include 10% by weight.

In addition, in the solid propellant composition, the equivalent ratio of the isocyanate group (-NCO) of the curing agent and the hydroxyl group (-OH) of the binder is 0.7 to 0.8, and the crosslinking agent containing two or more reactive functional groups is 0.04 based on the total weight of the solid propellant composition It may further include 0.12% by weight to 0.12% by weight.

In addition, the solid composition may further include a curing catalyst, and the curing catalyst may include 0.01 wt% to 1.2 wt% based on the total weight of the solid propellant composition.

Hereinafter, each configuration of the solid propellant composition will be described in more detail.

bookbinder

The binder structurally provides a matrix in which the solid granular components are held together in a composite propellant. The raw material may be provided as a prepolymer or a monomer, which may then be polymerized to form a polymer. The binder can affect the mechanical and chemical properties of the solid propellant composition, processing and aging of the propellant. The binder material may generally serve as a fuel that is oxidized during the combustion of the solid propellant composition.

The binder includes a hydroxyl terminated polymer having a hydroxyl group at the terminal thereof. For example, the hydroxyl terminated polymer may include hydroxyl terminated polyether, hydroxyl terminated polybutadiene, or a combination thereof. have.

For example, the binder may be hydroxyl terminated polybutadiene (HTPB). Hydroxyl terminated polybutadiene can exhibit a high solid fraction.

The binder is included in an amount of 1 wt% to 20 wt% based on the total weight of the solid propellant composition. When the binder is included in the above content, the propellant manufacturing process can be smoothly made by a sufficient curing reaction.

When the binder is included in less than 1% by weight, hardening is not made and the mechanical properties of the propellant cannot be obtained. Such propellant performance may be reduced.

hardener

A curing agent is added to impart curability to the binder polymer when polymerization of the binder is completed to become a binder polymer. The curing agent includes an isocyanate-based compound.

For example, the isocyanate-based compound may be a diisocyanate-based compound including two isocyanate functional groups. As another example, the isocyanate-based compound may have a dimer structure.

The curing agent may include dimer diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, or a combination thereof.

The curing agent may be included in an amount of 1% to 15% by weight based on the total weight of the solid propellant composition. When the curing agent is included in the above range, appropriate stress and hardness for use in the performance and adhesion of the propellant composition may be exhibited.

oxidizer

The oxidizing agent is a major component that produces high energy during combustion of the solid propellant composition, and the oxidizing agent is used in consideration of characteristics including compatibility with other components, good performance and solubility. The oxidizing agent includes a perchlorate compound. For example, the perchlorate compound may be ammonium perchlorate.

The oxidizing agent may be included in an amount of 60 wt% to 70 wt% based on the total weight of the solid propellant composition. When the oxidizing agent is included in the above content, the solid propellant composition can be combusted at an appropriate temperature and at an appropriate rate.

plasticizer

Plasticizers are relatively low-viscosity organic liquids that contribute to the thermal energy for oxidation of the solid propellant composition. The plasticizer is added to improve the explosive properties of the solid propellant composition, and includes an ester-based compound.

As an example, the plasticizer may be represented by Formula 1 below.

[Formula 1]

In Formula 1,

R ¹ and R ³ are each independently a C5 to C15 chain or branched alkyl group,

R ² is a C1 to C10 chain alkyl group,

N is 0 or 1.

For example, the plasticizer may include dioctyl sebacate, dioctyl adipate, isodecyl pelargonate, or a combination thereof.

The plasticizer may be included in an amount of 1 wt% to 10 wt% based on the total weight of the solid propellant composition. When the plasticizer is included in the above range, it is possible to exhibit high combustion performance while ensuring the safety of the solid propellant composition.

binder

The binder is added to bind the components included in the solid propellant composition so that they are not separated from each other, and includes an amine-based compound, an aziridine-based compound, an amide-based compound, or a combination thereof. For example, bis-isophthaloyl-1-methylaziridine, trimesoyl-1-(2-ethyl) aziridine, polyamine, tetraethylene pentaamine ( tetraethylene pentamine), or a combination thereof. The polyamine or the tetraethylene pentaamine may each independently include a cyanoethyl substituent.

The binder may be included in an amount of 0.1 wt% to 10 wt% based on the total weight of the solid propellant composition. When the binder is included in the above range, each component of the solid propellant composition can be smoothly combined without affecting the combustion performance of the solid propellant composition, and an appropriate viscosity can be maintained.

On the other hand, the equivalent ratio of the solid propellant composition is 0.7 to 0.8. For example, it may be 0.71 to 0.79, for example, 0.73 to 0.78, for example, 0.75 to 0.77, for example, it may be 0.755 to 0.765. When the equivalent ratio of the solid propellant composition is within the above range, the deformation rate of the solid propellant composition after curing is maintained in an appropriate range, thereby preventing cracks from occurring.

curing catalyst

The curing catalyst is used to control the reaction time, and it is preferable to use triphenylbismuth (hereinafter referred to as TPB), and it is used in an amount of 0.01 wt% to 1.2 wt% based on the total weight of the propellant composition. When the curing catalyst is included in an amount exceeding 1.2% by weight, the curing reaction occurs very quickly and curing may proceed during propellant mixing, and curing proceeds during the process of charging the propellant, making it impossible to charge. In addition, when the curing catalyst is used in an amount of less than 0.01% by weight, the curing reaction occurs very slowly, making it impossible to prepare a propellant.

Meanwhile, the solid propellant composition may further include other additives such as a crosslinking agent or a metal fuel in addition to the binder, curing agent, oxidizing agent, plasticizer and binder described above. Hereinafter, these will be described in more detail.

crosslinking agent

A crosslinking agent is added so that the prepolymer of the binder forms longer chains of higher molecular weight and causes interlocks between the chains. The binder may be coagulated and hardened by the crosslinking agent.

The crosslinking agent includes two or more reactive functional groups. The reactive functional group may include, for example, a hydroxyl group, a vinyl group, an epoxy group, or a combination thereof.

For example, the crosslinking agent may be a triol-based compound including three hydroxyl functional groups, for example, trimethylol propane.

The crosslinking agent may be included in an amount of 0.01 wt% to 10 wt% based on the total weight of the solid propellant composition. The crosslinking agent is a material that improves the bonding strength of polymer chains, and when included in the above range, the strain rate and strength of the solid propellant composition including the polymer material may be maintained at a certain level.

metal fuel

Metallic fuels may be added to improve properties of the solid propellant composition, such as heat of combustion, propellant density, and combustion temperature. The metal fuel may be a metal such as aluminum or boron, for example, aluminum.

Meanwhile, the metal fuel is a solid particle having a diameter of 5 μm to 60 μm.

The metal fuel may be included in an amount of 10% to 20% by weight based on 100% by weight of the solid propellant composition. When the content of the metal fuel is less than 10% by weight relative to 100% by weight of the solid propellant composition, the performance of the solid propellant such as specific thrust may be reduced. In addition, when the content of the metal fuel is greater than 20% by weight compared to 100% by weight of the solid propellant composition, there may be problems in fairness such as increase in viscosity when manufacturing the propellant, and mechanical properties of the propellant such as strength and elongation may be reduced.

On the other hand, an embodiment of the method for preparing a solid propellant composition according to the present invention includes a premixing step (S100) of injecting a binder raw material into a vacuum mixer.

As an example, the binder raw material is a binder including a hydroxyl terminated polymer.

As an example, the binder raw material further includes a binder and a plasticizer in addition to the binder.

The binder is a polymer material having a hydroxyl group (-OH), and includes, for example, hydroxyl terminated polyether, hydroxyl terminated polybutadiene, or a combination thereof. do.

The binder is added to bind the components included in the solid propellant composition so that they are not separated from each other, and may include an amine-based compound, an aziridine-based compound, an amide-based compound, or a combination thereof.

In addition, the plasticizer may include an ester-based compound.

In the premixing step (S100), 1 wt% to 20 wt% of a binder, 1 wt% to 10 wt% of a plasticizer, and 0.1 wt% to 10 wt% of a binder to the total weight of the solid propellant composition are injected into the vacuum mixer.

After the premixing step (S100), a first solid raw material injection step (S200) of injecting a part of the solid raw material of the solid propellant composition, ie, a part of the oxidizing agent, into the vacuum mixer is performed.

In the first solid raw material injection step (S200), 45 wt% to 55 wt% of the total weight of the solid raw material is injected into the vacuum mixer as an example.

The solid raw material includes an oxidizing agent, and in the first solid raw material injection step (S200), the oxidizing agent is injected into the vacuum mixer in an amount of 27 wt% to 38.5 wt% of the total weight of the solid composition.

It turns out that it is 45% to 55% by weight of the total weight of the oxidizing agent comprising 60% to 70% by weight of the total weight of the solid composition.

In addition, the solid raw material may further include a metal fuel, and the first solid raw material injection step (S200) is performed by vacuum mixing 45% to 55% by weight of the total weight% of the oxidizing agent and the metal fuel included in the entire solid composition. Injection into a fire is an example.

Since the metal fuel is included in an amount of 10 wt% to 20 wt% based on 100 wt% of the solid propellant composition, it is included in an amount of 4.5 wt% to 11 wt% in the first solid raw material injection step (S200).

After the first solid raw material injection step (S200), the first vacuum mixing step (S300) is performed, and the premixing step (S100), the first solid raw material injection step (S200), and the first vacuum mixing step (S300) of the vacuum mixer The internal temperature is maintained between 55°C and 65°C.

In addition, in the first solid raw material injection step (S200), the solid raw material is injected into the vacuum mixer at an injection rate of 45 kg/min to 55 kg/min.

In the pre-mixing step, the first solid raw material injection step (S200), a stirring process by a mixer blade is performed in a vacuum mixer to mix the binder raw material and the solid raw material.

That is, the pre-mixing step is a first stirring process in which a plurality of raw materials, that is, a binder, a plasticizer, and a binder, are injected into a vacuum mixer whose internal temperature is maintained at 55°C to 65°C and mixed with a mixer blade, and the first solid raw material injection Step (S200) is a second stirring process in which a part of the solid raw material is stirred while injecting it into the vacuum mixer at an injection rate of 45 kg/min to 55 kg/min after the first stirring process.

In the second stirring process, part of the solid raw material, that is, 45 wt% to 55 wt% of the total solid raw material in the solid propellant composition is stirred while injecting into the vacuum mixer at an injection rate of 45 kg/min to 55 kg/min.

In the first solid raw material injection step (S200), a solid raw material having particles larger than a preset particle size among the solid raw materials is injected using a screw feeder at an injection rate of 45 kg/min to 55 kg/min.

The screw feeder injects the solid raw material into the vacuum mixer at an injection rate of 45 kg/min to 55 kg/min while repeating that the screw feeder operates for 2-6 seconds and stops for 20-30 seconds.

When the screw feeder is continuously operated and the solid raw material is continuously injected into the vacuum mixer, the raw material is agglomerated and a large pressure may be generated on the mixer blade, there is a problem in the mixing process, and the raw material is not evenly mixed.

In the first solid raw material injection step (S200), the solid raw material is injected while the screw feeder is intermittently operated to prevent aggregation of the raw material in the vacuum mixer and to allow the raw material to be mixed evenly.

On the other hand, after the first solid raw material injection step (S200), the first vacuum mixing step (S300) is made, and after the first vacuum mixing step (S300), the vacuum state inside the vacuum mixer is released and the rest of the solid raw material A second solid raw material injection step (S400) of injecting into the vacuum mixer is made.

The second solid raw material injection step (S400) is a third stirring process in which the remainder of the solid raw material is injected into the vacuum mixer and the vacuum mixed raw material and the mixer blade are stirred.

In the second solid raw material injection step (S400), the remainder injected in the first solid raw material injection step (S200) of the total weight of the solid raw material, that is, 45 wt% to 55 wt% of the total weight of the solid raw material is injected into the vacuum mixer to do it as an example.

The solid raw material includes an oxidizing agent, and in the second solid raw material injection step (S400), the oxidizing agent is injected into the vacuum mixer in an amount of 27 wt% to 38.5 wt% of the total weight of the solid composition.

It turns out that it is 45% to 55% by weight of the total weight of the oxidizing agent comprising 60% to 70% by weight of the total weight of the solid composition.

In addition, the solid raw material may further include a metal fuel, and the second solid raw material injection step (S400) is performed by vacuum mixing 45% to 55% by weight of the total weight% of the oxidizing agent and the metal fuel included in the entire solid composition. Injection into a fire is an example.

Since the metal fuel is included in an amount of 10% to 20% by weight relative to 100% by weight of the solid propellant composition, it is included in an amount of 4.5% by weight to 11% by weight in the second solid raw material injection step (S400).

In the second solid raw material injection step (S400), the internal temperature of the vacuum mixer is maintained at 55°C to 65°C.

In addition, in the second solid raw material injection step (S400), the solid raw material is injected into the vacuum mixer at an injection rate of 10 kg/min to 20 kg/min.

In the second solid raw material injection step (S400), a stirring process by a mixer blade is performed in a vacuum mixer to mix the binder raw material and the solid fuel.

That is, in the second solid raw material injection step (S400), the remaining solid raw material is injected into a vacuum mixer whose internal temperature is maintained at 55 ° C. to 65 ° C. 3 is the stirring process.

In the third stirring process, the remainder of the solid raw material, that is, 45 wt% to 55 wt% of the total solid raw material in the solid propellant composition is stirred while injecting into the vacuum mixer at an injection rate of 10 kg/min to 20 kg/min.

In the second solid raw material injection step (S400), a solid raw material having particles smaller than a predetermined particle size among the solid raw materials is injected using a screw feeder at an injection rate of 45 kg/min to 55 kg/min.

The screw feeder injects the solid raw material into the vacuum mixer at an injection rate of 10kg/min ~ 20kg/min while repeating that the screw feeder operates for 2-6 seconds and stops for 25-35 seconds.

When the screw feeder is continuously operated and the solid raw material is continuously injected into the vacuum mixer, the raw material is agglomerated and a large pressure may be generated on the mixer blade, there is a problem in the mixing process, and the raw material is not evenly mixed.

In the second solid raw material injection step (S400), the solid raw material is injected while the screw feeder is intermittently operated to prevent aggregation of the raw material in the vacuum mixer and to allow the raw material to be mixed evenly.

After the second solid raw material injection step (S400), the second vacuum mixing step (S500) is made, and after the second vacuum mixing step (S500), the vacuum state inside the vacuum mixer is released and the curing agent is simultaneously introduced into the vacuum mixer A curing agent injection step (S600) to be injected is made.

In the curing agent injection step (S600), 1 wt% to 15 wt% of the curing agent may be injected with respect to the total weight of the solid propellant composition, and a curing catalyst may be further injected.

In the curing agent injection step (S600), 0.01 wt% to 1.2 wt% of the curing catalyst may be injected with respect to the total weight of the solid propellant composition.

The curing agent injection step (S600) is a fourth stirring process in which a binder raw material and a solid raw material are mixed, a curing agent and a curing catalyst are injected in a vacuum-mixed state, and the mixture is stirred with a mixer blade.

And, the curing agent injection step (S600) is in a state in which the internal temperature of the vacuum mixer is lowered to 45°C to 54°C, that is, the internal temperature of the vacuum mixer is 7 to 13°C lower than the second vacuum mixing step (S500). In the maintained state, the curing agent and the curing catalyst are injected to lower the reactivity of the curing agent and the curing catalyst during the final mixing process, thereby lowering the viscosity of the solid propellant composition.

In addition, the method for producing a solid propellant composition according to the present invention lowers the viscosity of the propellant by mixing a binder raw material and a solid raw material and finally injecting a curing agent and a curing catalyst.

After the curing agent injection step (S600), a third vacuum mixing step (S700) is performed, and the third vacuum mixing step (S700) is performed while the internal temperature of the vacuum mixer is maintained at 45°C to 54°C, that is, the curing agent injection The solid propellant composition is vacuum blended at the same temperature as in step (S600).

In the method for producing a solid propellant composition according to the present invention, the raw materials of the solid propellant composition are separately injected, and the raw materials are appropriately dispersed and mixed through vacuum mixing in the middle of the injection.

In addition, in the method for producing a solid propellant composition according to the present invention, a solid raw material is intermittently injected into a vacuum mixer with a screw feeder in the first solid raw material injection step (S200) and the second solid raw material injection step (S400), and the injection speed is adjusted By doing so, the mixing efficiency of the solid propellant composition is improved by preventing excessive load from being generated on the mixer blade, causing malfunction of the mixer blade, etc., and enabling even mixing of raw materials through a stable stirring process.

And, the method for preparing the solid propellant composition according to the present invention is

Table 1 below shows a method for preparing a solid propellant composition for Comparative Examples and Examples of the present invention.

In Table 1 below, the comparative example of the present invention prepares a solid propellant composition while maintaining the temperature of the vacuum mixer at 60° C., and injects the curing catalyst together into the binder raw material in the premix step (S100), and all of the solid raw material This is an example of preparing a solid propellant composition through a final vacuum mixing process after mixing with the binder raw material at once, vacuum mixing, and injecting a curing agent after vacuum mixing.

In addition, in the embodiment of the present invention in Table 1 below, the premix step (S100), the first solid raw material injection step (S200), the first vacuum mixing step (S300), The second solid raw material injection step (S400) is performed, and the second vacuum mixing step (S500), the curing agent injection step (S600), the third vacuum mixing step (S700) in a state where the temperature of the vacuum mixer is maintained at 50 ° C. This is an example of preparing a solid propellant composition by controlling the injection rate of the solid raw material by intermittently operating the screw feeder by setting the operating time and stopping time at the same time.

comparative example Example order Contents mixing temperature order Contents mixing temperature
Screw time, sec Feeding speed (kg/min) on off One Premix (binder raw material and curing catalyst injection) 60℃ One premix
(Inject binder raw material) 60℃ 2 Solid raw material injection 60℃ 2 Injection of the first solid raw material
(1/2 of the total solid raw material): large particle raw material 60℃ 4 26 50 3 vacuum mixing 60℃ 3 1st vacuum mixing 60℃ 4 2nd solid raw material injection
(1/2 of the total solid raw material): small particle raw material 60℃ 3 27 15 5 Second vacuum mixing 50℃ 4 hardener injection 60℃ 6 Injection of curing agent and curing catalyst 50℃ 5 Final vacuum mixing 60℃ 7 3rd vacuum mixing 50℃

It is a photograph taken of the solid propellant composition and the solid propellant composition prepared in Examples of the present invention, and FIG. It is a graph showing the viscosity of the solid propellant composition after the curing agent was added.

Referring to FIGS. 2 and 3 , it can be seen that the viscosity of the solid propellant composition prepared in Examples of the present invention is low compared to the viscosity of the solid propellant composition prepared in Comparative Examples of the present invention.

In addition, FIG. 4 is a graph showing the mechanical properties of the solid propellant prepared with the solid propellant composition of Comparative Example and the solid propellant prepared with the solid propellant composition of Examples in the method for preparing the solid propellant composition according to the present invention.

Referring to FIG. 4 , when the mechanical properties of the solid propellant prepared from the solid propellant composition of Comparative Example and the solid propellant prepared from the solid propellant composition of Examples in the method for preparing the solid propellant composition according to the present invention are compared, the mechanical properties of the solid propellant composition prepared in Examples of the present invention are compared. It can be confirmed that the mechanical properties of the solid propellant are better.

According to the present invention, raw materials for producing solid propellants are divided and injected into a vacuum mixer, and a vacuum mixing process is performed between each injection step, and the curing agent is injected last among the raw materials and then the final vacuum mixing process is performed to lower the viscosity of the propellant. It can prevent the occurrence of defects such as pores or cracks inside the solid propellant and improve the quality of the solid propellant.

The present invention enables stable solid propellant operation by preventing rocket explosion accidents due to defects such as pores or cracks in the solid propellant, increases the mixing efficiency of the solid propellant, and increases the mechanical properties of the propellant due to this improved viscosity. can

It should be noted that the present invention is not limited to the above-described embodiments, and can be implemented with various modifications without departing from the gist of the present invention, which is included in the configuration of the present invention.

S100 : premix stage
S200: first solid raw material injection step
S300: first vacuum mixing step
S400: 2nd solid raw material injection step
S500: second vacuum mixing step
S600: hardener injection step
S700: 3rd vacuum mixing step

Claims (15)

A method for preparing a solid propellant composition for preparing a solid propellant,
A premixing step of injecting a binder raw material into the vacuum mixer, a first solid raw material injection step of injecting a portion of the solid raw material of the solid propellant composition excluding the curing agent into the vacuum mixer;
A first vacuum mixing step of vacuum mixing some of the binder raw material and the solid raw material;
a second solid raw material injection step of injecting the remainder of the solid raw material of the solid propellant composition except for the curing agent into the vacuum blender after the first vacuum blending step;
a second vacuum mixing step of vacuum mixing the binder raw material and the solid raw material after the second solid raw material injection step;
a curing agent injection step of injecting a curing agent into the vacuum mixer after the second vacuum mixing step; and
After the curing agent injection step, a method for producing a solid propellant composition comprising a third vacuum mixing step of vacuum mixing the binder raw material, the solid raw material, and the curing agent.
The method according to claim 1,
The solid raw material is a method for producing a solid propellant composition, characterized in that it comprises an oxidizing agent and a metal fuel.
The method according to claim 1,
The first solid raw material injection step is a method of producing a solid propellant composition, characterized in that by injecting 45 wt% to 55 wt% of the total weight of the solid raw material into a vacuum mixer and stirring.
The method according to claim 1,
In the premixing step, the first solid raw material injection step, and the first vacuum mixing step, the internal temperature of the vacuum mixer is maintained at 55°C to 65°C.
4. The method according to claim 3,
The first solid raw material injection step is a method for producing a solid propellant composition, characterized in that injecting the solid raw material into the vacuum mixer at an injection rate of 45 kg / min ~ 55 kg / min.
4. The method according to claim 3,
In the first solid raw material injection step, a solid raw material having particles larger than a predetermined particle size among the solid raw materials is injected using a screw feeder at an injection rate of 45 kg/min to 55 kg/min,
The screw feeder operates for 2 to 6 seconds and stops for 20 to 30 seconds while repeating that the solid raw material is injected into the vacuum mixer at an injection rate of 45 kg/min to 55 kg/min. Preparation of a solid propellant composition Way.
4. The method according to claim 3,
The second solid raw material injection step is a method for producing a solid propellant composition, characterized in that by injecting 45 wt% to 55 wt% of the total weight of the solid raw material into the vacuum mixer.
8. The method of claim 7,
The method for producing a solid propellant composition, characterized in that the internal temperature of the vacuum mixer is maintained at 55 °C to 65 °C in the second solid raw material injection step.
8. The method of claim 7,
The second solid raw material injection step is a method for producing a solid propellant composition, characterized in that by injecting the solid raw material into the vacuum mixer at an injection rate of 10 kg / min ~ 20 kg / min and stirring.
8. The method of claim 7,
In the second solid raw material injection step, a solid raw material having particles smaller than a predetermined particle size among the solid raw materials is injected using a screw feeder at an injection rate of 10 kg/min to 20 kg/min. Preparation of a solid propellant composition Way.
11. The method of claim 10,
In the second solid raw material injection step, the screw feeder operates for 2 to 6 seconds and stops for 25 to 35 seconds while repeating that the solid raw material is injected into the vacuum mixer at an injection rate of 10 kg/min to 20 kg/min. A process for the preparation of a solid propellant composition, characterized in that
The method according to claim 1,
In the curing agent injection step, 1 wt% to 15 wt% of the curing agent is injected with respect to the total weight of the solid propellant composition, and a curing catalyst is further injected.
13. The method of claim 12,
The curing agent injection step is a method of producing a solid propellant composition, characterized in that by injecting a curing agent and a curing catalyst while maintaining the internal temperature of the vacuum mixer at 45 °C ~ 54 °C and stirring.
14. The method of claim 13,
The third vacuum mixing step is a method for producing a solid propellant composition, characterized in that the vacuum mixing of the solid propellant composition in a state where the internal temperature of the vacuum mixer is maintained at 45°C to 54°C.
A solid propellant composition prepared by the method for preparing the solid propellant composition of any one of claims 1 to 14.

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