Adhesive for internal thermal insulation layer of solid rocket engine as well as preparation method and application of adhesive

Abstract

The invention relates to the technical field of solid engine adhesives, and discloses a solid rocket engine internal insulation layer adhesive which comprises the following raw materials in parts by mass: 90-180 parts of silicone rubber, 10-30 parts of ablation-resistant filler, 20-40 parts of glass powder, 5-10 parts of polyborosiloxane, 4-8 parts of a cross-linking agent, 0.3-1 part of an inhibitor, 0.5-1 part of a tackifier and 10-20 parts of a catalyst. Due to the synergistic effect of the polyborosiloxane, the ablation-resistant filler and the glass powder, the adhesive is good in high-temperature bonding performance and excellent in ablation resistance, and the oxygen-acetylene line ablation rate is 0.8 mm / s-1. 0 mm / s. And in an environment of 350 DEG C, the interface of the silicon rubber internal heat insulation layer and the metal shell is still well bonded. The invention further discloses a preparation method and application of the solid rocket engine internal heat insulation layer adhesive, the solid rocket engine internal heat insulation layer adhesive is simple in brushing process, only one-time brushing is needed, next-step operation can be carried out after brushing, the period is short, and a long-time hot pre-pressing step is not needed.

Description

Technical Field

[0001] The present invention relates to the technical field of solid rocket motor adhesives, and particularly to an internal insulation layer adhesive for a solid rocket motor, a preparation method thereof, and an application thereof. Background Art

[0002] A solid rocket motor is a rocket power device with excellent performance, which consists of components such as a combustion chamber, a propellant, an igniter, and a nozzle. The combustion chamber is a container for storing the propellant and provides a space for combustion, and it has to withstand high temperatures above 3000 °C and the erosion of high-pressure gas flow. The internal insulation layer in the combustion chamber is a heat-insulating and protective material placed between the inner surface of the casing and the propellant. Its main function is to relieve the heat transfer rate of the high-temperature gas to the casing by continuously decomposing and ablating itself, so as to avoid the casing reaching a temperature that endangers the structural integrity and ensure the normal operation of the motor. In a solid rocket motor, in order to ensure the bonding performance at the interface between the motor casing and the internal insulation layer, an adhesive is usually used for curing to achieve bonding. Under the working conditions of production, storage, and transportation, the bonding layer of the solid rocket motor will be affected by various complex loads and environmental conditions, resulting in weak bonding or debonding problems, which will reduce the reliability of the solid rocket motor and even lead to failure.

[0003] The thermal insulation layer in the combustion chamber is generally a silicone rubber thermal insulation layer, and the silicone rubber is vulcanized silicone rubber. Vulcanized silicone rubber is a thermal insulation layer material with excellent ablation resistance, low smoke performance, and storage performance. However, the prominent disadvantage of vulcanized silicone rubber is its low surface energy, poor adhesion performance, and difficulty in forming a reliable bonding interface with the metal shell of the solid rocket engine, which has a great adverse impact on the application of the vulcanized silicone rubber thermal insulation layer. Ordinary organic silicone adhesives do not have ablation resistance and are prone to failure in high-temperature environments, restricting their bonding applications in the internal thermal insulation layer. The invention patent CN118725817A discloses a heat-curable silicone rubber adhesive, which has high bonding strength and good bonding stability. However, this adhesive does not have high-temperature resistance and ablation resistance. The invention patent CN119019976A discloses a two-component silicone rubber adhesive, which can effectively bond metals and composites, but this adhesive does not have ablation resistance. Chen Guohui et al. in "Analysis of Influencing Factors for the Bonding Performance of the Thermal Insulation Layer of Solid Rocket Engines" need to apply the adhesive in multiple coats and use hot air drying to remove the solvent during the application process. The process is relatively complex, requiring multiple coats and hot air drying. The invention patent CN104943184B discloses a method for pasting a thermal insulation layer sheet on a shell using an adhesive. This method requires a hot pre-pressing step, involves heat treatment, a long pressing time, and a cumbersome process. The invention patent CN102632683B discloses a method for manufacturing a manually pasted thermal insulation patch. This method can ensure the thickness dimension of the manually pasted thermal insulation patch. However, the manual patch production method has low efficiency and is prone to defects such as bulging, pits, and debonding, and is vulnerable to hot gas erosion, resulting in the failure of thermal protection and ultimately the explosion and disintegration of the combustion chamber. Therefore, in the prior art, there are still great defects in the adhesives and bonding process methods for bonding the interface between the vulcanized silicone rubber internal thermal insulation layer and the metal shell. There is an urgent need for an adhesive that is both high-temperature resistant and ablation resistant (i.e., the oxyacetylene linear ablation rate is lower than 0.07 mm / s) and has good coating and bonding process performance with low viscosity during use. Summary of the Invention

[0004] Based on the above, the object of the present invention is to provide an adhesive for the internal thermal insulation layer of a solid rocket engine, its preparation method and application, which can bond the interface between the silicone rubber internal thermal insulation layer and the metal shell, has excellent ablation resistance and high-temperature bonding performance, and at the same time has good coating and bonding process performance with low viscosity during use.

[0005] To achieve the above object, the present invention adopts the following technical solutions: An adhesive for the internal thermal insulation layer of a solid rocket engine, comprising the following raw materials in parts by mass: Silicone rubber 90 - 180 parts Ablation-resistant filler 10 - 30 parts Glass powder 20 - 40 parts 5 - 10 parts of polyborosiloxane 4 - 8 parts of crosslinking agent 0.3 - 1 part of inhibitor 0.5 - 1 part of constant viscosity thickener 10 - 20 parts of catalyst; The constant viscosity thickener is synthesized by hydrosilylation reaction from phenyltris(dimethylsiloxy)silane and cardanol polyoxyethylene ether with a mass ratio of (2.5 - 3.5):1.

[0006] As a preferred embodiment of the adhesive for the thermal insulation layer inside a solid rocket motor, the synthesis method of the constant viscosity thickener comprises the following steps: Add phenyltris(dimethylsiloxy)silane into a reactor equipped with a stirrer, a thermometer and a condensing reflux device; Introduce nitrogen and heat up to 80°C - 90°C; Add platinum catalyst and keep the temperature for a period of time, then start to slowly dropwise add cardanol polyoxyethylene ether; Start timing after the dropping is completed and carry out the reaction for 2.5 h - 3.5 h; The platinum catalyst includes platinum - vinylsiloxane complex.

[0007] As a preferred embodiment of the adhesive for the thermal insulation layer inside a solid rocket motor, the silicone rubber includes one or more of methyl vinyl silicone rubber, methyl vinyl phenyl silicone rubber, methyl phenyl silicone rubber, p - phenylene silicone rubber, phenylene silicone rubber and phenyl ether phenylene silicone rubber; the viscosity of the silicone rubber is 500 - 50000 mPa·s.

[0008] As a preferred embodiment of the adhesive for the thermal insulation layer inside a solid rocket motor, the ablation - resistant filler includes one or more of mica powder, diatomaceous earth powder, kaolin, silica lime powder, modified silicon carbide nanopowder, zirconia powder, magnesium carbonate, alumina powder; the particle size of the ablation - resistant filler is below 600 mesh.

[0009] As a preferred embodiment of the adhesive for the thermal insulation layer inside a solid rocket motor, the glass powder includes D233.

[0010] As a preferred embodiment of the adhesive for the thermal insulation layer inside a solid rocket motor, the viscosity of the polyborosiloxane is 500 - 5000 mPa·s.

[0011] As a preferred embodiment of the adhesive for the thermal insulation layer inside a solid rocket motor, the crosslinking agent includes hydrogen - containing silicone oil; the inhibitor includes one or more of 3 - methyl - 1 - butyn - 3 - ol, 3 - methyl - 1 - pentyn - 3 - ol, 3 - phenyl - 1 - butyn - 3 - ol.

[0012] A preparation method of an adiabatic layer adhesive in a solid rocket motor, comprising the following steps: Put silicone rubber, ablation-resistant filler, glass powder, and polyborosiloxane into the mixing barrel of a double planetary mixer according to a ratio, and perform vacuum degassing treatment to obtain a base material. Take a certain mass of the base material and put it into the mixing barrel of a double planetary mixer. Add a crosslinking agent, an inhibitor, and a constant viscosity thickener into the mixing barrel of the double planetary mixer according to a ratio, and stir evenly to obtain Component A. Take a certain mass of the base material and put it into the mixing barrel of a double planetary mixer. Add a catalyst according to a ratio and stir evenly to obtain Component B. Mix Component A and Component B evenly according to a mass ratio of (13 - 20):1 to obtain the adiabatic layer adhesive in the solid rocket motor.

[0013] Among them, the ratio of the mass parts of the base material in Component A and Component B is 126:(10 - 20).

[0014] As a preferred scheme of the preparation method of the adiabatic layer adhesive in the solid rocket motor, the vacuum degree of the vacuum pumping for the vacuum degassing treatment is -0.08 to -0.1 MPa, and the degassing treatment is that the mixing time is 0.5 - 2 h under the vacuum pumping state.

[0015] An application of the adiabatic layer adhesive in the solid rocket motor, comprising the following steps: Use sandpaper to polish the bonding area of the inner adiabatic layer head preform until it is rough and has no reflective surface, then use ethyl acetate to clean the polished area and leave it to dry at room temperature. Use emery to sandblast the bonding area of the inner surface of the metal shell until it is rough and has no reflective surface. Coat an epoxy-based silane coupling agent on both the treated bonding area of the inner adiabatic layer head preform and the bonding area of the inner surface of the metal shell, and leave it to dry at room temperature. Use a brush to dip the adhesive and evenly apply the adhesive on the treated bonding area of the inner adiabatic layer head preform and the bonding area of the inner surface of the metal shell where the epoxy-based silane coupling agent is coated. Fit the inner adiabatic layer head preform coated with the adhesive to the inner surface of the metal shell, and install the airbag and the airbag tooling. Slowly pressurize with the airbag to a certain pressure until the excess adhesive overflows, then transfer the airbag and the bonded inner adiabatic layer head preform and the metal shell to a heating device, perform heat treatment and then cool to complete the bonding of the inner adiabatic layer and the metal shell.

[0016] As a preferred solution for the application of an insulating layer adhesive in a solid rocket motor, the brushing thickness of the adhesive is 0.02 mm to 0.05 mm; when the airbag is pressurized, the required holding pressure is 0.3 MPa to 0.5 MPa, and the pressurization time is 5 min - 15 min. After heat treatment, the pressurization time is 0.5 h - 1.5 h.

[0017] The beneficial effects of the present invention are as follows: The present invention provides an insulating layer adhesive for a solid rocket motor. Under the synergistic action of polyborosiloxane, ablation-resistant filler, and glass powder, this adhesive has good high-temperature bonding performance. Ablation-resistant fillers such as mica and kaolin in this adhesive system act as skeletons during the heating process, and then cooperate with the glass powder to form a ceramic-like structure. The glass powder has excellent ceramic-forming effect, softens and melts above 300 °C, and bonds mica, kaolin, etc. together to form a continuous ceramic structure, thus making the adhesive have excellent high-temperature resistance. After the adhesive is used to bond the inner insulating layer and metal in a high-temperature environment of 350 °C, the result of peeling the inner insulating layer shows excellent adhesive performance. At the same time, the oxyacetylene linear ablation of this adhesive ≤ 0.07 mm / s, and the ablation resistance performance is excellent. Polyborosiloxane substances also have a certain self-tackifying effect on silicone rubber. The electron orbit of the B atom has an electron-deficient tendency, and the oxygen atom in the Si-O bond provides a pair of electrons to form a coordinate bond with the B atom. The bond energies of B-O bond and Si-O are 537.6 KJ / mol and 422.5 KJ / mol respectively, which are much higher than the bond energy of ordinary organosiloxane, making polyborosiloxane have higher thermal stability at high temperature, and thus showing excellent bonding performance at high temperature.

[0018] The insulating layer adhesive for a solid rocket motor provided by the present invention has excellent high-temperature resistance and ablation resistance, and the oxyacetylene linear ablation rate is less than 0.07 mm / s. This adhesive has good high-temperature bonding performance. At 350 °C, the interface between the silicone rubber inner insulating layer and the metal shell is still well bonded. At the same time, due to the low viscosity of the adhesive, the coating process performance is excellent, the brushing is simple, only one-time brushing is required, and the next step can be carried out immediately after brushing; the cycle is short, there is no need for a long-time hot pre-pressing step, and the pressure is smaller than the conventional 0.6 MPa - 0.8 MPa, only 0.3 MPa - 0.5 MPa is required. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the oxyacetylene linear ablation principle, and the direction of the red arrow is the direction of the ablation flame ablating the bonding test piece; Figure 2 It is a schematic diagram of the bonding performance test result after the bonding test piece is ablated. Detailed Embodiments

[0020] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosed content of the present invention more thorough and comprehensive. Unless otherwise defined, all technical and scientific terms used in the present invention belong to the technical field of the present invention.

[0021] This embodiment provides an adiabatic layer adhesive for a solid rocket motor, which comprises the following raw materials in parts by mass: 90 - 180 parts of silicone rubber, 10 - 30 parts of ablation-resistant filler, 20 - 40 parts of glass powder, 5 - 10 parts of polyborosiloxane, 4 - 8 parts of crosslinking agent, 0.3 - 1 part of inhibitor, 0.5 - 1 part of constant-viscosity tackifier, and 10 - 20 parts of catalyst.

[0022] Specifically, the silicone rubber includes one or more of methyl vinyl silicone rubber, methyl vinyl phenyl silicone rubber, methyl phenyl silicone rubber, p-phenylene silicone rubber, phenylene silicone rubber, and phenylether phenylene silicone rubber; the viscosity of the silicone rubber is 500 - 50000 mPa·s.

[0023] Specifically, the ablation-resistant filler includes one or more of mica powder, diatomaceous earth powder, kaolin, silica lime powder, modified silicon carbide nanofiber, zirconia powder, magnesium carbonate, and alumina powder; the particle size of the ablation-resistant filler is below 600 mesh; the glass powder includes D233, and this glass powder is in a molten state at 300°C - 350°C; the viscosity of the polyborosiloxane is 500 - 5000 mPa·s. Due to the synergistic effect of polyborosiloxane, ablation-resistant filler, and glass powder, ablation-resistant fillers such as mica and kaolin act as skeletons during the heating process, and then cooperate with each other under the action of glass powder to form a ceramic-like structure. The glass powder has excellent ceramic-forming effect, softens and melts above 300°C, and bonds mica, kaolin, etc. together to form a continuous ceramic structure, thus making the adhesive have excellent high-temperature resistance. Polyborosiloxane substances also have a certain self-tackifying effect on silicone rubber. The electron orbit of the B atom has an electron-deficient tendency, and the oxygen atom in the Si - O bond provides a pair of electrons to form a coordination bond with the B atom. The bond energies of B - O bond and Si - O are 537.6 KJ / mol and 422.5 KJ / mol respectively, which are much higher than the bond energy of ordinary organosiloxane, making the polyborosiloxane have higher thermal stability at high temperature, and thus showing excellent adhesive performance at high temperature.

[0024] Specifically, the crosslinking agent includes hydrogen-containing silicone oil; the inhibitor includes one or more of 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, and 3-phenyl-1-butyn-3-ol.

[0025] The constant-viscosity tackifier is self-made. Due to the low surface energy of the silicone rubber in the internal thermal insulation layer of the vulcanized silicone rubber, the bonding performance is poor. When using ordinary adhesives, it is difficult for the silicone rubber internal thermal insulation layer to form a reliable bonding interface with the metal shell of the solid rocket engine. Usually, the method to improve the bonding performance of the adhesive is to add a tackifier to the adhesive. However, adding a conventional tackifier to the silicone rubber-based adhesive will increase the viscosity of the adhesive. That is to say, if the constant-viscosity tackifier in the formula of the adhesive for the internal thermal insulation layer of the solid rocket engine of the present invention is replaced with a conventional tackifier, the viscosity of the prepared adhesive is 250,000 - 400,000 mPa·s, which makes its processability worse. Especially for coating the adhesive inside the metal shell, the too high viscosity is not conducive to coating, resulting in defects such as uneven surface of the adhesive and difficulty in spreading, and it simply cannot meet the use requirements. When the self-made constant-viscosity tackifier is added to the adhesive of the present invention, the viscosity of the prepared adhesive is 100,000 - 200,000 mPa·s. If the self-made constant-viscosity tackifier is removed according to the adhesive formula of the present invention, the viscosity of the prepared adhesive is also 100,000 - 200,000 mPa·s, indicating that adding the self-made constant-viscosity tackifier does not increase the viscosity of the silicone rubber-based adhesive of the present invention and can well meet the application bonding processability requirements for subsequently bonding the cured internal thermal insulation material of the solid rocket engine and the metal (steel) shell together.

[0026] The catalyst includes a platinum-vinylsiloxane complex.

[0027] This embodiment also provides a preparation method for an adhesive for the internal thermal insulation layer of a solid rocket engine, including the following steps: (1) Put silicone rubber, ablation-resistant filler, glass powder, and polyborosiloxane into the mixing barrel of a double planetary mixer according to the proportion, and perform vacuum degassing treatment to obtain a base material. (2) Take a certain mass of the base material and put it into the mixing barrel of the double planetary mixer. Add a crosslinking agent, an inhibitor, and a constant-viscosity tackifier into the mixing barrel of the double planetary mixer according to the proportion, and stir evenly to obtain Component A. (3) Take a certain mass of the base material and put it into the mixing barrel of the double planetary mixer. Add a catalyst according to the proportion and stir evenly to obtain Component B. (4) Mix Component A and Component B evenly according to the mass ratio of (13 - 20):1, and perform vacuum degassing treatment to obtain the adhesive for the internal thermal insulation layer of the solid rocket engine.

[0028] Among them, the proportion of the mass fraction of the base material in Component A and Component B is 126:(10 - 20).

[0029] Specifically, the vacuum degree in the vacuum state is -0.08 to -0.1 MPa, and the mixing time in the vacuum state is 0.5 - 2 h.

[0030] This embodiment also proposes an application of an adiabatic layer adhesive in a solid rocket motor, including the following steps: (1) Use 40-mesh to 80-mesh sandpaper to polish the bonding area of the prefabricated inner adiabatic layer head to be rough without a reflective surface, then clean the polished area with ethyl acetate and air-dry at room temperature for 20 min to 60 min; (2) Use emery to sandblast the bonding area of the inner surface of the metal shell to be rough without a reflective surface; (3) Coat epoxy-based silane coupling agent on both the treated bonding area of the prefabricated inner adiabatic layer head and the bonding area of the inner surface of the metal shell, and air-dry at room temperature for 20 min to 40 min; (4) Use a brush to dip the adiabatic layer adhesive in the solid rocket motor and evenly apply the adhesive on the bonding area of the prefabricated inner adiabatic layer head and the bonding area of the inner surface of the metal shell after coating the epoxy-based silane coupling agent; (5) Fit the prefabricated inner adiabatic layer head coated with the adhesive to the inner surface of the metal shell, and install the airbag and airbag tooling; (6) Slowly pressurize the airbag to a certain pressure until the excess adhesive overflows, then transfer the airbag, the bonded prefabricated inner adiabatic layer head and the metal shell to a heating device, heat-treat and then cool. Raise the temperature from room temperature to 150 °C at a heating rate of 20 °C / min, keep warm for 1 h, and then cool down to room temperature to complete the bonding of the inner adiabatic layer and the metal shell.

[0031] Specifically, the brushing thickness of the adhesive is 0.02 mm to 0.05 mm; when pressurizing the airbag, the required holding pressure is 0.3 MPa to 0.5 MPa, preferably 0.4 MPa, and the pressurizing time is 10 min; when heat-treating, raise the temperature from room temperature to 150 °C at a heating rate of 20 °C / min, keep warm for 1 h, and then cool down to room temperature.

[0032] The brushing process of the above adhesive application is simple, only requiring one-time brushing, and the next operation can be carried out immediately after brushing; the cycle is short, without the need for a long-time hot pre-pressing step, and the pressure is smaller than the conventional 0.6 MPa to 0.8 MPa, only requiring 0.3 MPa to 0.5 MPa.

[0033] The following further illustrates the present invention through specific embodiments. Example 1

[0034] An adiabatic layer adhesive in a solid rocket motor includes the following components in parts by mass: 150 parts of methyl vinyl silicone rubber (viscosity 500 mPa·s), 30 parts of mica powder, 20 parts of D233 glass powder, 5 parts of polyborosiloxane (viscosity 600 mPa·s), 6 parts of hydrogen-containing silicone oil, 0.5 part of 3-phenyl-1-butyn-3-ol, 0.5 part of constant viscosity tackifier, 16 parts of platinum-vinyl silicone complex.

[0035] A preparation method of an adiabatic layer adhesive in a solid rocket motor, comprising the following steps: Put 150 parts of methyl vinyl silicone rubber, 30 parts of mica powder, 20 parts of glass powder, and 5 parts of polyborosiloxane into the mixing barrel of a double planetary mixer in sequence, and perform vacuum degassing treatment on the rubber compound to prepare a base material, wherein the vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min; Take 126 parts of the base material and put it into the mixing barrel of a double planetary mixer, add 6 parts of hydrogen-containing silicone oil and 0.5 part of 3-phenyl-1-butyn-3-ol into the mixing barrel of the double planetary mixer, and stir evenly to obtain Component A; Take 15 parts of the base material and put it into the mixing barrel of a double planetary mixer, add 16 parts of platinum-vinyl silicone complex, and stir evenly to obtain Component B.

[0036] Pack Component A and Component B separately with plastic barrels and seal them well, wherein the mixing mass ratio of Component A and Component B is 13:1, and the viscosity after mixing is 130210 mPa·s.

[0037] If adding the silicone rubber tackifier T907 produced by the conventional Wuhan Anruike Materials Co., Ltd., and other preparation methods are exactly the same, the prepared adhesive has a viscosity of 265830 mPa·s.

[0038] Determination is carried out according to the method of "GB / T 2794-2022 Determination of Adhesive Viscosity".

[0039] An application of an adiabatic layer adhesive in a solid rocket motor, comprising the following steps: Use 40-mesh to 80-mesh sandpaper to polish the bonding area of the prefabricated inner adiabatic layer head to be rough without a reflective surface; Use emery to sandblast the bonding area of the inner surface of the metal shell to be rough without a reflective surface; Mix Component A and Component B of the adhesive according to a mass ratio of 13:1, stir evenly, and perform vacuum degassing treatment on the rubber compound. The vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min to obtain the required adhesive; Use ethyl acetate to clean the polished area and leave it to dry at room temperature for 20 min to 60 min; Coat the epoxy - type silane coupling agent on the bonding area of the inner thermal insulation head pre - form, and coat the epoxy - type silane coupling agent on the bonding area of the inner surface of the metal shell. Leave it to dry at room temperature for 20 min to 40 min; Use a brush to pick up the degassed adhesive and evenly apply it on the bonding area of the inner thermal insulation head pre - form and the bonding area of the inner surface of the metal shell. Control the thickness of the adhesive to be 0.02 mm to 0.05 mm; Fit the inner thermal insulation head pre - form with the inner surface of the metal shell; install the airbag and the airbag tooling; Slowly pressurize with the airbag, maintain the pressure at 0.3 MPa, let the excess adhesive overflow, and transfer the engine shell (including the head pre - form and the airbag) to the heating device within 10 min. Raise the temperature from room temperature to 150 °C at a heating rate of 20 °C / min, keep it warm for 1 h, and then cool it down to room temperature. Complete the bonding of the inner thermal insulation layer and the metal shell. Example 2

[0040] An adhesive for the inner thermal insulation layer of a solid rocket motor, comprising the following components in parts by mass: 180 parts of methyl vinyl phenyl silicone rubber (viscosity 10000 mPa·s), 20 parts of diatomaceous earth powder, 30 parts of D233 glass powder, 8 parts of polyborosiloxane (viscosity 800 mPa·s), 8 parts of hydrogen - containing silicone oil, 1 part of 3 - phenyl - 1 - butyn - 3 - ol, 0.8 part of constant - viscosity tackifier, 20 parts of platinum - vinylsiloxane complex.

[0041] A preparation method of an adhesive for the inner thermal insulation layer of a solid rocket motor, comprising the following steps: Put 180 parts of methyl vinyl phenyl silicone rubber, 20 parts by mass of diatomaceous earth powder, 30 parts of glass powder, and 8 parts of polyborosiloxane into the mixing barrel of a double - planetary mixer in sequence. Carry out vacuum degassing treatment on the rubber compound to prepare the base material. Among them, the vacuum degree in the vacuum state is - 0.08 MPa to - 0.1 MPa, and the time in the vacuum state is 5 min to 10 min; Take 126 parts of the base material and put it into the mixing barrel of the double - planetary mixer. Add 8 parts of hydrogen - containing silicone oil and 1 part by mass of 3 - phenyl - 1 - butyn - 3 - ol to the mixing barrel of the double - planetary mixer, and stir evenly to obtain Component A; Take 20 parts by mass of the base material and put it into the mixing barrel of the double - planetary mixer. Add 20 parts by mass of platinum - vinylsiloxane complex and stir evenly to obtain Component B.

[0042] Package Component A and Component B separately with plastic barrels and seal them well. The mixing ratio of Component A and Component B is 17:1, and the viscosity after mixing is 145471 mPa·s.

[0043] If a conventional silicone rubber tackifier T907 produced by Wuhan Anruike Materials Co., Ltd. is added and other preparation methods are exactly the same, the viscosity of the prepared adhesive is 282502 mPa·s.

[0044] The measurement is carried out according to the method of "GB / T 2794-2022 Determination of Viscosity of Adhesives".

[0045] The application of an adhesive for the internal insulation layer of a solid rocket motor includes the following steps: Use 40-mesh to 80-mesh sandpaper to polish the bonding area of the prefabricated internal insulation layer head to be rough without a reflective surface; Use emery to sandblast the bonding area of the inner surface of the metal shell to be rough without a reflective surface; Mix component A and component B of the adhesive in a mass ratio of 17:1, stir evenly, and subject the rubber compound to vacuum degassing treatment. The vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min to obtain the required adhesive; Use ethyl acetate to clean the polished area and leave it to dry at room temperature for 20 min to 60 min; Coat epoxy-based silane coupling agent on the bonding area of the prefabricated internal insulation layer head and coat epoxy-based silane coupling agent on the bonding area of the inner surface of the metal shell, and leave it to dry at room temperature for 20 min to 40 min; Use a brush to dip the degassed adhesive and evenly apply it on the bonding area of the prefabricated internal insulation layer head and the bonding area of the inner surface of the metal shell. The thickness of the adhesive is controlled at 0.02 mm to 0.05 mm; Fit the prefabricated internal insulation layer head with the inner surface of the metal shell; install the airbag and the airbag tooling; Slowly pressurize using the airbag, maintain a pressure of 0.4 MPa, and let the excess adhesive overflow. Transfer the engine shell (including the prefabricated head and the airbag) to the heating device within 10 min, raise the temperature from room temperature to 150 °C at a heating rate of 20 °C / min, keep the temperature for 1 h, and then cool down to room temperature. Complete the bonding of the internal insulation layer and the metal shell. Example 3

[0046] A kind of adhesive for the internal insulation layer of a solid rocket motor, comprising the following components: 90 parts of methylphenyl silicone rubber (viscosity 50000 mPa·s), 10 parts of zirconia powder, 40 parts of D233 glass powder, 10 parts of polyborosiloxane (viscosity 900 mPa·s), 4 parts of hydrogen-containing silicone oil, 0.3 part of 3-methyl-1-pentyn-3-ol, 1 part of constant viscosity tackifier, 10 parts of platinum-vinylsiloxane complex.

[0047] A preparation method of an adhesive for the internal insulation layer of a solid rocket motor, comprising the following steps: Put 90 parts by mass of methylphenyl silicone rubber, 10 parts by mass of zirconia powder, 40 parts of glass powder, and 10 parts of polyborosiloxane into the mixing barrel of a double planetary mixer in sequence. Perform vacuum degassing treatment on the rubber compound to prepare the base material. Among them, the vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min; Take 126 parts by mass of the base material and put it into the mixing barrel of a double planetary mixer. Add 4 parts by mass of hydrogen-containing silicone oil and 0.3 parts by mass of 3-methyl-1-pentyne-3-ol into the mixing barrel of the double planetary mixer, and stir evenly to obtain Component A; Take 10 parts by mass of the base material and put it into the mixing barrel of a double planetary mixer. Add 10 parts by mass of platinum-vinyl silicone complex and stir evenly to obtain Component B.

[0048] Package Component A and Component B separately with plastic barrels and seal them well. The mixing ratio of Component A and Component B is 20:1, and the viscosity after mixing is 160154 mPa·s.

[0049] If a conventional silicone rubber tackifier T907 produced by Wuhan Anruike Materials Co., Ltd. is added and other preparation methods are exactly the same, the viscosity of the prepared adhesive is 312520 mPa·s.

[0050] Determination is carried out according to the method of "GB / T 2794-2022 Determination of Adhesive Viscosity".

[0051] The application of an adhesive for the internal thermal insulation layer of a solid rocket motor includes the following steps: Use 40-mesh to 80-mesh sandpaper to polish the bonding area of the prefabricated inner thermal insulation layer head to be rough without a reflective surface; Use emery to sandblast the bonding area of the inner surface of the metal shell to be rough without a reflective surface; Mix Component A and Component B of the adhesive according to a mass ratio of 20:1, stir evenly, and perform vacuum degassing treatment on the rubber compound. The vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min to obtain the required adhesive; Use ethyl acetate to clean the polished area and air dry it at room temperature for 20 min to 60 min; Coat epoxy-based silane coupling agent on the bonding area of the prefabricated inner thermal insulation layer head and on the bonding area of the inner surface of the metal shell, and air dry it at room temperature for 20 min to 40 min; Use a brush to dip the degassed adhesive and evenly apply it on the bonding area of the prefabricated inner thermal insulation layer head and on the bonding area of the inner surface of the metal shell. The thickness of the adhesive is controlled at 0.02 mm to 0.05 mm; Fit the prefabricated inner thermal insulation layer head with the inner surface of the metal shell; install the airbag and the airbag tooling; Slowly pressurize using the airbag, maintain a pressure of 0.5 MPa, let the excess adhesive overflow, transfer the engine shell (including the prefabricated head and the airbag) to the heating device within 10 min, raise the room temperature to 150 °C at a heating rate of 20 °C / min, keep warm for 1 h, and then cool down to room temperature. Complete the bonding of the inner thermal insulation layer and the metal shell.

[0052] To further illustrate the key points of this patent, a comparative case is added for explanation.

[0053] Comparative Example 1 An adhesive for the inner thermal insulation layer of a solid rocket engine, comprising the following components: 150 parts of methyl vinyl phenyl silicone rubber (viscosity 500 mPa·s), 30 parts of mica powder, 5 parts of polyborosiloxane (viscosity 600 mPa·s), 6 parts of hydrogen-containing silicone oil, 0.5 part of 3-phenyl-1-butyn-3-ol, 0.5 part of a constant viscosity tackifier, and 16 parts of a platinum-vinyl silicone complex.

[0054] A preparation method of an adhesive for the inner thermal insulation layer of a solid rocket engine, comprising the following steps: Put 150 parts by mass of methyl vinyl phenyl silicone rubber, 30 parts by mass of mica powder, and 5 parts of polyborosiloxane into the mixing barrel of a double planetary mixer in sequence, conduct vacuum defoaming treatment on the rubber material to prepare a base material, wherein the vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min; Take 126 parts by mass of the base material and put it into the mixing barrel of a double planetary mixer, add 6 parts by mass of hydrogen-containing silicone oil and 0.5 part by mass of 3-phenyl-1-butyn-3-ol into the mixing barrel of the double planetary mixer, and stir evenly to obtain Component A; Take 15 parts by mass of the base material and put it into the mixing barrel of a double planetary mixer, add 16 parts by mass of the platinum-vinyl silicone complex, and stir evenly to obtain Component B.

[0055] Pack Component A and Component B separately in plastic barrels and seal them well, wherein the mixing ratio of Component A and Component B is 13:1, and the viscosity after mixing is 110210 mPa·s.

[0056] An application of an adhesive for the inner thermal insulation layer of a solid rocket engine, comprising the following steps: Use 40-mesh to 80-mesh sandpaper to polish the bonding area of the prefabricated inner thermal insulation layer head until it is rough and has no reflective surface; Use emery to sandblast the bonding area of the inner surface of the metal shell until it is rough and has no reflective surface; Mix component A and component B of the adhesive in a mass ratio of 13:1, stir evenly, subject the rubber compound to vacuum defoaming treatment, with the vacuum degree in the vacuum state being -0.08 MPa to -0.1 MPa and the time in the vacuum state being 5 min to 10 min to obtain the required adhesive; Clean the polished area with ethyl acetate and leave it to dry at room temperature for 20 min to 60 min; Coat epoxy-based silane coupling agent on the bonding area of the inner thermal insulation layer head prefabrication and on the bonding area of the inner surface of the metal shell, and leave it to dry at room temperature for 20 min to 40 min; Use a brush to dip the defoamed adhesive and evenly apply it on the bonding area of the inner thermal insulation layer head prefabrication and on the bonding area of the inner surface of the metal shell, with the thickness of the adhesive controlled at 0.02 mm to 0.05 mm; Fit the inner thermal insulation layer head prefabrication with the inner surface of the metal shell; install the airbag and the airbag tooling; Slowly pressurize using the airbag, maintain the pressure at 0.3 MPa, let the excess adhesive overflow, transfer the engine shell (including the head prefabrication and the airbag) to the heating device within 10 min, raise the temperature from room temperature to 150 °C at a heating rate of 20 °C / min, keep it warm for 1 h, and then cool it down to room temperature. Complete the bonding of the inner thermal insulation layer and the metal shell.

[0057] Comparative Example 2 A solid rocket engine inner thermal insulation layer adhesive, comprising the following components: 150 parts of methyl vinyl phenyl silicone rubber (viscosity 500 mPa·s), 30 parts of mica powder, 20 parts of D233 glass powder, 6 parts of hydrogen-containing silicone oil, 0.5 part of 3-phenyl-1-butyn-3-ol, 0.5 part of constant viscosity tackifier, 16 parts of platinum-vinylsiloxane complex.

[0058] A preparation method of a solid rocket engine inner thermal insulation layer adhesive, comprising the following steps: Put 150 parts by mass of methyl vinyl phenyl silicone rubber, 30 parts by mass of mica powder, and 20 parts of glass powder into the mixing barrel of a double planetary mixer in sequence, subject the rubber compound to vacuum defoaming treatment to prepare the base material, wherein the vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa and the time in the vacuum state is 5 min to 10 min; Take 126 parts by mass of the base material and put it into the mixing barrel of the double planetary mixer, add 6 parts by mass of hydrogen-containing silicone oil and 0.5 part by mass of 3-phenyl-1-butyn-3-ol to the mixing barrel of the double planetary mixer, stir evenly to obtain component A; Take 15 parts by mass of the base material and put it into the mixing barrel of the double planetary mixer, add 16 parts by mass of platinum-vinylsiloxane complex, stir evenly to obtain component B.

[0059] The A component and the B component are respectively packaged in plastic drums and well sealed. The mixing ratio of the A component and the B component is 13:1, and the viscosity after mixing is 110251 mPa·s.

[0060] The application of an adhesive for the internal thermal insulation layer in a solid rocket motor includes the following steps: Use 40-mesh to 80-mesh sandpaper to polish the bonding area of the prefabricated head of the internal thermal insulation layer until it is rough and has no reflective surface; Use emery to sandblast the bonding area of the inner surface of the metal shell until it is rough and has no reflective surface; Mix the A component and the B component of the adhesive in a mass ratio of 13:1, stir evenly, and perform vacuum degassing treatment on the rubber compound. The vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min to obtain the required adhesive; Use ethyl acetate to clean the polished area and leave it to dry at room temperature for 20 min to 60 min; Apply an epoxy-based silane coupling agent to the bonding area of the prefabricated head of the internal thermal insulation layer and apply an epoxy-based silane coupling agent to the bonding area of the inner surface of the metal shell, and leave it to dry at room temperature for 20 min to 40 min; Use a brush to dip the degassed adhesive and evenly apply it to the bonding area of the prefabricated head of the internal thermal insulation layer and the bonding area of the inner surface of the metal shell. The thickness of the adhesive is controlled at 0.02 mm to 0.05 mm; Fit the prefabricated head of the internal thermal insulation layer with the inner surface of the metal shell; install the airbag and the airbag tooling; Slowly pressurize using the airbag, maintain a pressure of 0.3 MPa, and let the excess adhesive overflow. Transfer the engine shell (including the prefabricated head and the airbag) to the heating device within 10 min, raise the temperature from room temperature to 150 °C at a heating rate of 20 °C / min, keep the temperature for 1 h, and then cool down to room temperature. Complete the bonding of the internal thermal insulation layer and the metal shell.

[0061] Comparative Example 3 A kind of adhesive for the internal thermal insulation layer in a solid rocket motor includes the following components: 150 parts of methyl vinyl phenyl silicone rubber (viscosity 500 mPa·s), 30 parts of mica powder, 6 parts of hydrogen-containing silicone oil, 0.5 part of 3-phenyl-1-butyn-3-ol, 0.5 part of constant viscosity tackifier, 16 parts of platinum-vinyl siloxane complex.

[0062] A preparation method of an adhesive for the internal thermal insulation layer in a solid rocket motor includes the following steps: Put 150 parts by mass of methyl vinyl phenyl silicone rubber and 30 parts by mass of mica powder into the mixing barrel of a double planetary mixer in sequence, and subject the rubber compound to vacuum degassing treatment to prepare a base material. Among them, the vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min; Take 126 parts by mass of the base material and put it into the mixing barrel of a double planetary mixer. Add 6 parts by mass of hydrogen-containing silicone oil and 0.5 parts by mass of 3-phenyl-1-butyn-3-ol into the mixing barrel of the double planetary mixer, and stir evenly to obtain Component A; Take 15 parts by mass of the base material and put it into the mixing barrel of a double planetary mixer. Add 16 parts by mass of platinum-vinylsiloxane complex, and stir evenly to obtain Component B.

[0063] Pack Component A and Component B separately in plastic barrels and seal them well. The mixing ratio of Component A and Component B is 13:1, and the viscosity after mixing is 125410 mPa·s.

[0064] The application of an adhesive for the internal insulation layer of a solid rocket motor includes the following steps: Use 40-mesh to 80-mesh sandpaper to polish the bonding area of the prefabricated internal insulation layer head to be rough without a reflective surface; Use emery to sandblast the bonding area of the inner surface of the metal shell to be rough without a reflective surface; Mix Component A and Component B of the adhesive in a mass ratio of 13:1, stir evenly, and subject the rubber compound to vacuum degassing treatment. The vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min to obtain the required adhesive; Use ethyl acetate to clean the polished area and leave it to dry at room temperature for 20 min to 60 min; Coat epoxy-based silane coupling agent on the bonding area of the prefabricated internal insulation layer head and on the bonding area of the inner surface of the metal shell, and leave it to dry at room temperature for 20 min to 40 min; Use a brush to dip the degassed adhesive and evenly apply it on the bonding area of the prefabricated internal insulation layer head and on the bonding area of the inner surface of the metal shell. The thickness of the adhesive is controlled at 0.02 mm to 0.05 mm; Fit the prefabricated internal insulation layer head with the inner surface of the metal shell; install the airbag and the airbag tooling; Slowly pressurize with the airbag, maintain the pressure at 0.3 MPa, let the excess adhesive overflow, transfer the engine shell (including the prefabricated head and the airbag) to the heating device within 10 min, raise the temperature from room temperature to 150 °C at a heating rate of 20 °C / min, keep it warm for 1 h, and then cool it down to room temperature. Complete the bonding of the internal insulation layer and the metal shell.

[0065] Comparative Example 4 An adiabatic layer adhesive inside a solid rocket motor, comprising the following components in parts by mass: 150 parts of methyl vinyl silicone rubber (viscosity 500 mPa·s), 30 parts of mica powder, 20 parts of D233 glass powder, 5 parts of polyborosiloxane (viscosity 400 mPa·s), 6 parts of hydrogen-containing silicone oil, 0.5 part of 3-phenyl-1-butyn-3-ol, 0.5 part of constant viscosity tackifier, 16 parts of platinum-vinylsiloxane complex.

[0066] A preparation method of an adiabatic layer adhesive inside a solid rocket motor, comprising the following steps: Put 150 parts of methyl vinyl silicone rubber, 30 parts of mica powder, 20 parts of glass powder, and 5 parts of polyborosiloxane into the mixing barrel of a double planetary mixer in sequence, and subject the rubber material to vacuum degassing treatment to prepare a base material, wherein the vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min; Take 126 parts of the base material and put it into the mixing barrel of a double planetary mixer, add 6 parts of hydrogen-containing silicone oil and 0.5 part of 3-phenyl-1-butyn-3-ol into the mixing barrel of the double planetary mixer, and stir evenly to obtain Component A; Take 15 parts of the base material and put it into the mixing barrel of a double planetary mixer, add 16 parts of platinum-vinylsiloxane complex, and stir evenly to obtain Component B.

[0067] Package Component A and Component B separately with plastic barrels and seal them well, wherein the mixing mass ratio of Component A and Component B is 13:1, and the viscosity after mixing is 124102 mPa·s.

[0068] An application of an adiabatic layer adhesive inside a solid rocket motor, comprising the following steps: Use 40-mesh to 80-mesh sandpaper to polish the bonding area of the prefabricated inner adiabatic layer head to be rough without a reflective surface; Use emery to sandblast the bonding area of the inner surface of the metal shell to be rough without a reflective surface; Mix Component A and Component B of the adhesive in a mass ratio of 13:1, stir evenly, and subject the rubber material to vacuum degassing treatment. The vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min to obtain the required adhesive; Use ethyl acetate to clean the polished area and air dry it at room temperature for 20 min to 60 min; Coat epoxy-based silane coupling agent on the bonding area of the prefabricated inner adiabatic layer head, and coat epoxy-based silane coupling agent on the bonding area of the inner surface of the metal shell, and air dry it at room temperature for 20 min to 40 min; Use a brush to pick up the degassed adhesive and evenly apply it to the bonding area of the inner insulation layer head preform and the inner surface of the metal shell. The thickness of the adhesive is controlled between 0.02 mm and 0.05 mm; Fit the inner insulation layer head preform to the inner surface of the metal shell; install the airbag and airbag tooling; Slowly pressurize using the airbag, maintain a pressure of 0.3 MPa, let the excess adhesive overflow, and transfer the engine shell (including the head preform and airbag) to the heating device within 10 min. Raise the room temperature to 150 °C at a heating rate of 20 °C / min, keep it warm for 1 h, and then cool it down to room temperature. Complete the bonding of the inner insulation layer and the metal shell.

[0069] Comparative Example 5 An adhesive for the inner insulation layer of a solid rocket motor, comprising the following components in parts by mass: 150 parts of methyl vinyl silicone rubber (viscosity of 500 mPa·s), 30 parts of mica powder, 20 parts of D233 glass powder, 5 parts of polyborosiloxane (viscosity of 6000 mPa·s), 6 parts of hydrogen-containing silicone oil, 0.5 part of 3-phenyl-1-butyn-3-ol, 0.5 part of a constant viscosity tackifier, 16 parts of a platinum-vinyl silicone complex.

[0070] A preparation method of an adhesive for the inner insulation layer of a solid rocket motor, comprising the following steps: Put 150 parts of methyl vinyl silicone rubber, 30 parts of mica powder, 20 parts of glass powder, and 5 parts of polyborosiloxane into the mixing barrel of a double planetary mixer in sequence, and perform vacuum degassing treatment on the rubber material to prepare a base material. Among them, the vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min; Take 126 parts of the base material and put it into the mixing barrel of a double planetary mixer. Add 6 parts of hydrogen-containing silicone oil and 0.5 part of 3-phenyl-1-butyn-3-ol to the mixing barrel of the double planetary mixer, and stir evenly to obtain Component A; Take 15 parts of the base material and put it into the mixing barrel of a double planetary mixer. Add 16 parts of a platinum-vinyl silicone complex, and stir evenly to obtain Component B.

[0071] Pack Component A and Component B separately in plastic barrels and seal them well. Among them, the mixing mass ratio of Component A and Component B is 13:1, and the viscosity after mixing is 124102 mPa·s.

[0072] An application of an adhesive for the inner insulation layer of a solid rocket motor, comprising the following steps: Use 40-mesh to 80-mesh sandpaper to polish the bonding area of the inner insulation layer head preform until it is rough and has no reflective surface; Use emery to sandblast the bonding area of the inner surface of the metal shell until it is rough and has no reflective surface; Mix component A and component B of the adhesive in a mass ratio of 13:1, stir evenly, subject the rubber compound to vacuum defoaming treatment, with the vacuum degree in the vacuum state being -0.08 MPa to -0.1 MPa and the time in the vacuum state being 5 min to 10 min, to obtain the required adhesive; Clean the polished area with ethyl acetate and leave it to dry at room temperature for 20 min to 60 min; Coat epoxy silane coupling agent on the bonding area of the inner thermal insulation layer head prefabricated part and on the bonding area of the inner surface of the metal shell, and leave it to dry at room temperature for 20 min to 40 min; Use a brush to dip the defoamed adhesive and evenly apply it on the bonding area of the inner thermal insulation layer head prefabricated part and on the bonding area of the inner surface of the metal shell, with the thickness of the adhesive controlled at 0.02 mm to 0.05 mm; Fit the inner thermal insulation layer head prefabricated part with the inner surface of the metal shell; install the airbag and the airbag tooling; Slowly pressurize with the airbag, maintain the pressure at 0.3 MPa, let the excess adhesive overflow, transfer the engine shell (including the head prefabricated part and the airbag) to the heating device within 10 min, raise the temperature from room temperature to 150 °C at a heating rate of 20 °C / min, keep the temperature for 1 h, and then cool down to room temperature. Complete the bonding of the inner thermal insulation layer and the metal shell.

[0073] Comparative Example 6 An adhesive for the inner thermal insulation layer of a solid rocket motor, comprising the following components in parts by mass: 150 parts of methyl vinyl silicone rubber (viscosity 500 mPa·s), 30 parts of mica powder, 20 parts of D233 glass powder, 5 parts of polyborosiloxane (viscosity 600 mPa·s), 6 parts of hydrogen-containing silicone oil, 0.5 part of 3-phenyl-1-butyn-3-ol, 0.5 part of constant viscosity tackifier, 16 parts of platinum-vinylsiloxane complex.

[0074] A preparation method of an adhesive for the inner thermal insulation layer of a solid rocket motor, comprising the following steps: Put 150 parts of methyl vinyl silicone rubber, 30 parts of mica powder, 20 parts of glass powder, and 5 parts of polyborosiloxane into the mixing barrel of a double planetary mixer in sequence, subject the rubber compound to vacuum defoaming treatment to prepare the base material, wherein the vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa and the time in the vacuum state is 5 min to 10 min; Take 126 parts of the base material and put it into the mixing barrel of the double planetary mixer, add 6 parts of hydrogen-containing silicone oil and 0.5 part of 3-phenyl-1-butyn-3-ol into the mixing barrel of the double planetary mixer, stir evenly to obtain component A; Put 15 parts of the base material into the mixing barrel of a double planetary mixer, add 16 parts of a platinum-vinylsiloxane complex, and stir evenly to obtain Component B.

[0075] Pack Component A and Component B separately in plastic drums and seal them well. The mixing mass ratio of Component A and Component B is 13:1, and the viscosity after mixing is 130210 mPa·s.

[0076] The application of an adhesive for the internal insulation layer of a solid rocket motor includes the following steps: Use 40-mesh to 80-mesh sandpaper to polish the bonding area of the prefabricated inner insulation layer head to be rough without a reflective surface. Use emery to sandblast the bonding area of the inner surface of the metal shell to be rough without a reflective surface. Mix Component A and Component B of the adhesive in a mass ratio of 13:1, stir evenly, and subject the adhesive to vacuum degassing treatment. The vacuum degree in the vacuum state is -0.08 MPa to -0.1 MPa, and the time in the vacuum state is 5 min to 10 min to obtain the required adhesive. Clean the polished area with ethyl acetate and leave it to dry at room temperature for 20 min to 60 min. Coat an epoxy-based silane coupling agent on the bonding area of the prefabricated inner insulation layer head and on the bonding area of the inner surface of the metal shell, and leave it to dry at room temperature for 20 min to 40 min. Use a brush to dip the degassed adhesive and evenly apply it to the bonding area of the prefabricated inner insulation layer head and the bonding area of the inner surface of the metal shell. The thickness of the adhesive is controlled at 0.02 mm to 0.05 mm. Place the engine shell into the vacuum chamber, close the chamber door, and perform vacuum pumping treatment with a vacuum pump. The vacuum degree is less than -0.096 MPa. After reaching the vacuum degree, maintain the pressure for 1 - 3 h, and then slowly introduce air with an air intake speed controlled at 100 L / min. Place the engine shell into the heating device, pressurize it inside the rubber airbag with a pressure of 0.6 - 0.8 MPa, and heat it at a temperature of 80°C - 100°C for 1 - 3 h. Then, reduce the temperature and pressure to normal temperature and pressure, and take out the engine shell from the heating device. Flaw detection step: Use a digital ultrasonic flaw detector to detect all the bonding interfaces of the insulation layer to check for any debonding phenomenon. Curing step: Place the rubber airbag inside the engine shell, and then place the engine shell into the heating device. Pressurize the rubber airbag to 1.1 MPa ± 0.1 MPa, raise the temperature to 110°C ± 5°C and keep it warm for 2 hours, then raise the temperature at a rate of 15°C / h to 165°C ± 5°C and keep it warm for 1 hour, then lower the temperature at a rate of 15°C / h to 100°C ± 5°C, and finally lower the temperature to room temperature. Take out the engine shell to complete the formation of the insulation layer inside the engine shell.

[0077] The adhesives, the completed bonded inner thermal insulation layer head prefabricated parts and the metal shells prepared in Examples 1-3 and Comparative Examples 1-6 were subjected to performance tests. The test standards are as follows: the shear performance is QJ2038.2, the peel strength is QJ2038.1A, and the oxyacetylene linear ablation rate is GJB 323A.

[0078] The conclusion can be drawn that: The inner thermal insulation layer adhesive for solid rocket engines provided by the present invention has excellent ablation resistance, and the oxy-acetylene linear ablation rate is less than 0.07 mm / s. The adhesive has good high-temperature bonding performance. At an environment of 350 °C, the interface between the silicone rubber inner thermal insulation layer and the metal (D406A steel) shell is still well bonded. After the adhesive bonds the inner thermal insulation layer and the metal shell at a high temperature of 350 °C (thermocouple), the performance test is shown in the following figure, where Figure 1 is a schematic diagram of the oxy-acetylene linear ablation principle, and the direction of the red arrow is the direction of the ablation flame ablating the bonded test piece; Figure 2 is a schematic diagram of the bonding performance test results after the bonded test piece is ablated. The black circles from left to right are named the 1st, 2nd, 3rd, and 4th bonded test pieces in sequence. The 1st and 2nd bonded test pieces are the adhesives without adding glass powder and the adhesives without adding polyborosiloxane in Comparative Examples 1 and 2. The peeling interfaces of the 1st and 2nd bonded test pieces are damaged, and only the metal (D406A steel) remains, indicating that the high-temperature bonding performance of the adhesives prepared in Comparative Examples 1 and 2 is not good. The 3rd and 4th bonded test pieces are the test pieces bonded with the adhesives of the present application in Examples 1 and 2. After ablation, the lower half of the thermal insulation layer of the 3rd and 4th test pieces is peeled off, and there is still a residue of adhesive + thermal insulation layer, indicating that its bonding performance is good and it cannot be completely peeled off even by manual peeling; the upper half is not peeled, and the residue is adhesive + thermal insulation layer (the white part in the middle is the thermal insulation layer); after the lower half of the 3rd and 4th bonded test pieces is peeled off, the inner thermal insulation layer body and the adhesive are damaged, indicating that the bonding between the metal shell and the adhesive and between the adhesive and the inner thermal insulation layer is good at 350 °C.

[0079] Specifically: The shear strength between the completed bonded inner thermal insulation layer head prefabricated part and the metal shell in Example 1 is 2.02 MPa, the peel strength is 2.03 MPa, and the bonding quality between the inner thermal insulation layer head prefabricated part and the metal shell is good. Under the assessment of oxy-acetylene linear ablation, no interface peeling or foaming phenomenon occurs. The oxy-acetylene linear ablation rate of the adhesive is 0.05 mm / s. The bonding between the shell / adhesive and the adhesive / inner thermal insulation layer is good at 350 °C. After peeling, the adhesive and the inner thermal insulation body are damaged, indicating that the bonding between the metal shell and the adhesive and between the adhesive and the inner thermal insulation layer is good at 350 °C.

[0080] In Example 2, the shear strength of the prefabricated inner insulation layer head bonded to the metal shell is 2.16 MPa, and the peel strength is 2.23 MPa. The bonding quality between the prefabricated inner insulation layer head and the metal shell is good. Under the assessment of oxy-acetylene line ablation, no interface peeling or foaming occurs. The oxy-acetylene line ablation rate of the adhesive is 0.06 mm / s. The bonding between the shell / adhesive and the adhesive / inner insulation layer is good at 350 °C. After peeling, the adhesive and the inner insulation body are damaged. The bonding between the metal shell and the adhesive and between the adhesive and the inner insulation layer is good at 350 °C.

[0081] In Example 3, the shear strength of the prefabricated inner insulation layer head bonded to the metal shell is 2.01 MPa, and the peel strength is 2.00 MPa. The bonding quality between the prefabricated inner insulation layer head and the metal shell is good. Under the assessment of oxy-acetylene line ablation, no interface peeling or foaming occurs. The oxy-acetylene line ablation rate of the adhesive is 0.05 mm / s. The bonding between the shell / adhesive and the adhesive / inner insulation layer is good at 350 °C. After peeling, the adhesive and the inner insulation body are damaged. The bonding between the metal shell and the adhesive and between the adhesive and the inner insulation layer is good at 350 °C.

[0082] Compared with Example 1, in Comparative Example 1, no glass powder is added. The shear strength of the prefabricated inner insulation layer head bonded to the metal shell is 2.01 MPa, and the peel strength is 2.00 MPa. The interlayer bonding quality is good. Under the assessment of oxy-acetylene line ablation, no interface peeling or foaming occurs. The oxy-acetylene line ablation rate of this adhesive is 0.08 mm / s. The bonding between the shell / adhesive and between the adhesive and the inner insulation layer is not good at 350 °C. The peeling occurs at the interface between the adhesive and the metal shell.

[0083] In Comparative Example 2, no polyborosiloxane is added. The shear strength of the prefabricated inner insulation layer head bonded to the metal shell is 1.85 MPa, and the peel strength is 1.98 MPa. The interlayer bonding quality is good. Under the assessment of oxy-acetylene line ablation, no interface peeling or foaming occurs. The oxy-acetylene line ablation rate of this adhesive is 0.08 mm / s. The bonding performance between the shell / adhesive and the adhesive / inner insulation layer is not good at 350 °C. The peeling occurs at the interface between the adhesive and the metal shell.

[0084] In Comparative Example 3, neither glass powder nor polyborosiloxane was added. The shear strength of the prefabricated inner thermal insulation layer head bonded to the metal shell was 1.41 MPa, and the peel strength was 1.32 MPa. The interlayer bonding quality was average. Under the oxygen-acetylene line ablation test, no interface peeling or blistering occurred. The oxygen-acetylene line ablation rate of this adhesive was 0.11 mm / s. The bonding performance of the shell / adhesive and adhesive / inner thermal insulation layer was poor at 350°C, and the peeling occurred at the interface between the adhesive and the inner thermal insulation layer.

[0085] In Comparative Example 4, the viscosity of polyborosiloxane was 400 mPa·s. The shear strength of the prefabricated inner thermal insulation layer head bonded to the metal shell was 1.98 MPa, and the peel strength was 1.95 MPa. The interlayer bonding quality was good. Under the oxygen-acetylene line ablation test, no interface peeling or blistering occurred. The oxygen-acetylene line ablation rate of this adhesive was 0.13 mm / s. The bonding performance of the shell / adhesive and adhesive / inner thermal insulation layer was poor at 350°C, and the peeling occurred at the interface between the adhesive and the inner thermal insulation layer.

[0086] In Comparative Example 5, the viscosity of polyborosiloxane was 6000 mPa·s. The shear strength of the prefabricated inner thermal insulation layer head bonded to the metal shell was 1.95 MPa, and the peel strength was 1.92 MPa. The interlayer bonding quality was good. Under the oxygen-acetylene line ablation test, no interface peeling or blistering occurred. The oxygen-acetylene line ablation rate of this adhesive was 0.12 mm / s. The bonding performance of the shell / adhesive and adhesive / inner thermal insulation layer was poor at 350°C, and the peeling occurred at the interface between the adhesive and the inner thermal insulation layer.

[0087] In Comparative Example 6, the shear strength of the prefabricated inner thermal insulation layer head bonded to the metal shell was 2.00 MPa, and the peel strength was 2.01 MPa. The bonding quality between the prefabricated inner thermal insulation layer head and the metal shell was good. Under the oxygen-acetylene line ablation test, no interface peeling or blistering occurred. The oxygen-acetylene line ablation rate of the adhesive was 0.05 mm / s. The shell / adhesive and adhesive / inner thermal insulation layer were both well bonded at 350°C. After peeling, the inner thermal insulation layer body and the adhesive were damaged. However, its process is more cumbersome and has a longer cycle than the process of the present invention.

[0088] In summary, through the synergistic effect of polyborosiloxane, ablation-resistant filler, and glass powder, the present application has good high-temperature bonding performance, excellent ablation resistance of the adhesive, and an oxygen-acetylene linear ablation rate ≤ 0.07 mm / s. At an environment temperature of 350°C, the interface between the silicone rubber internal insulation layer and the metal shell still has good bonding. In addition, the painting process of the adhesive is simple, only requiring a one-time painting, and the next operation can be carried out immediately after painting; the cycle is short, only requiring 10 minutes of cold pressing and 1 hour of hot pressing, without the 1-hour to 3-hour hot pre-pressing step in the prior art, and the pressure is smaller than the conventional 0.6 MPa to 0.8 MPa, only requiring 0.3 MPa to 0.5 MPa.

[0089] The above are only the preferred embodiments of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An adiabatic layer adhesive inside a solid rocket motor, characterized in that, Comprising the following raw materials in parts by mass: Silicone rubber 90 - 180 parts Ablation-resistant filler 10 - 30 parts Glass powder 20 - 40 parts Polyborosiloxane 5 - 10 parts Crosslinking agent 4 - 8 parts Inhibitor 0.3 - 1 part Constant-viscosity thickener 0.5 - 1 part Catalyst 10 - 20 parts; The constant-viscosity thickener is synthesized by hydrosilylation reaction with phenyltris(dimethylsiloxy)silane and cardanol polyoxyethylene ether as raw materials in a mass ratio of (2.5 - 3.5):

1.

2. The adiabatic layer adhesive inside a solid rocket motor according to claim 1, characterized in that, The synthesis method of the constant-viscosity thickener comprises the following steps: Add phenyltris(dimethylsiloxy)silane into a reactor equipped with a stirrer, a thermometer and a condensation reflux device; Introduce nitrogen and heat up to 80°C - 90°C; Add a platinum catalyst and keep the temperature for a period of time, then start to slowly dropwise add cardanol polyoxyethylene ether; Start timing after the dropping is completed and carry out the reaction for 2.5 h - 3.5 h; The platinum catalyst includes a platinum-vinylsiloxane complex.

3. The adiabatic layer adhesive inside a solid rocket motor according to claim 1, characterized in that, The silicone rubber includes one or more of methyl vinyl silicone rubber, methyl vinyl phenyl silicone rubber, methyl phenyl silicone rubber, p-phenylene silicone rubber, phenylene silicone rubber and phenyl ether phenylene silicone rubber; the viscosity of the silicone rubber is 500 - 50000 mPa·s.

4. The adiabatic layer adhesive inside a solid rocket motor according to claim 1, characterized in that, The ablation-resistant filler includes one or more of mica powder, diatomaceous earth powder, kaolin, silica lime powder, modified silicon carbide nanofiber, zirconia powder, magnesium carbonate, alumina powder; the particle size of the ablation-resistant filler is below 600 mesh.

5. The adiabatic layer adhesive inside a solid rocket motor according to claim 1, characterized in that, The glass powder is D233.

6. The adiabatic layer adhesive inside a solid rocket motor according to claim 1, characterized in that, The viscosity of the polyborosiloxane is 500 - 50000 mPa·s.

7. The adiabatic layer adhesive inside a solid rocket motor according to claim 1, characterized in that, The crosslinking agent includes hydrogen-containing silicone oil; the inhibitor includes one or more of 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3-phenyl-1-butyn-3-ol.

8. A preparation method of an adiabatic layer adhesive inside a solid rocket motor, characterized in that, Comprising the following steps: Put silicone rubber, ablation-resistant filler, glass powder, polyborosiloxane into the mixing barrel of a double planetary mixer according to the proportion, carry out vacuum degassing treatment to prepare the base material; Take a certain mass of the base material and put it into the mixing barrel of the double planetary mixer, add the crosslinking agent, inhibitor, constant-viscosity thickener into the mixing barrel of the double planetary mixer according to the proportion, and stir evenly to obtain Component A; Take a certain mass of the base material and put it into the mixing barrel of the double planetary mixer, add the catalyst according to the proportion and stir evenly to obtain Component B; Mix Component A and Component B evenly according to a mass ratio of (13 - 20):1 to obtain the adhesive for the internal insulation layer of a solid rocket motor; Among them, the proportion of the mass of the base material in Component A and Component B is 126:(10 - 20); The vacuum degree of the vacuum degassing treatment is -0.08 to -0.1 MPa, and the degassing treatment is a mixing time of 0.5 - 2 h under vacuum.

9. Application of an adhesive for the thermal insulation layer inside a solid rocket motor, wherein the adhesive is the adhesive for the thermal insulation layer inside a solid rocket motor described in any one of claims 1-8, characterized in that, Comprising the following steps: Use sandpaper to polish the bonding area of the prefabricated inner insulation layer head to be rough and without a reflective surface, then clean the polished area with ethyl acetate and leave it to dry at room temperature; Use emery to sandblast the bonding area of the inner surface of the metal shell to be rough and without a reflective surface; Coat epoxy silane coupling agent on both the bonding area of the prefabricated inner thermal insulation layer head and the inner surface of the metal shell after processing, and leave it to dry at room temperature; Dip a brush into the adhesive and evenly apply the adhesive on the bonding area of the prefabricated inner thermal insulation layer head and the inner surface of the metal shell after coating with epoxy silane coupling agent; Fit the prefabricated inner thermal insulation layer head coated with the adhesive to the inner surface of the metal shell, and install the airbag and airbag tooling; Slowly pressurize the airbag to a certain pressure until the excess adhesive overflows. Then transfer the airbag, the bonded prefabricated inner thermal insulation layer head and the metal shell to a heating device, heat-treat and then cool to complete the bonding of the inner thermal insulation layer and the metal shell.

10. Application of the adhesive for the thermal insulation layer inside a solid rocket motor according to claim 9, characterized in that, The brushing thickness of the adhesive is 0.02mm - 0.05mm; when pressurizing the airbag, the required pressure to be maintained is 0.3MPa - 0.5MPa, and the pressurizing time is 5min - 15min. After heat treatment, the pressurizing time is 0.5h - 1.5h.

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