A launch vehicle coating cleaning agent and a preparation method thereof

Abstract

This invention discloses a rocket casing cleaning agent and its preparation method, belonging to the field of rocket casing cleaning technology. The cleaning agent comprises the following components by mass percentage: 10%-20% decafluoro-3-methoxy-2-trifluoromethylpentane, 50%-70% hydrofluoroether, 2%-20% fluoroalcohol, 1%-5% cyclohexane, and 1%-5% co-solvent. The components selected in this invention are free from heavy metals, strong alkalis, nitrites, phosphorus, amines, amides, and highly toxic and volatile organic solvents such as chlorinated hydrocarbons, phenols, and ketones. It possesses the functions of cleaning dirt and protecting coatings, high cleaning power, safety, environmental friendliness, energy saving, and an ODP value of 0. It provides excellent cleaning effect, long-lasting cleaning, and effectively improves coating adhesion; it does not damage the aluminum-based material of the casing; the preparation method is simple and easy to implement, with a high safety factor during cleaning, and the waste liquid can be recycled, making it economical, safe, energy-saving, and environmentally friendly. It effectively solves the problems of high toxicity, strong odor, low flash point, and environmental damage associated with traditional cleaning agents.

Description

Technical Field

[0001] This invention belongs to the field of rocket shell cleaning technology, and in particular relates to a carrier rocket coating cleaning agent and its preparation method. Background Technology

[0002] Currently, the main coatings used on the surface of my country's launch vehicle shells are H06-2 epoxy ester primer and H04-2 epoxy nitrocellulose enamel. Before painting, the shell surface needs to be cleaned of oil stains with 120# gasoline. 120# gasoline's main components are aliphatic hydrocarbons, which have good affinity for various oils and are widely used in pre-coating treatment. Although gasoline is the most commonly used cleaning solvent in rocket pre-coating treatment, its low flash point makes it flammable and explosive, posing extremely high risks and significant safety hazards during transportation, storage, and use. Open flames are strictly prohibited in gasoline usage areas, and storage areas must be cool, well-ventilated, and equipped with anti-static measures. With the rapid development of my country's aerospace industry, gasoline consumption is gradually increasing, and the risk of flammability and explosion in production areas is also rising sharply.

[0003] When cleaning the launch vehicle casing, the most important aspects are ensuring the performance of the coating, including its corrosion resistance, flammability, volatility, impact strength, adhesion, and resistance to damp heat. This includes using a cleaning agent that effectively removes oil, dust, and mechanical impurities; ensuring no damage to the aluminum substrate after cleaning; possessing good environmental performance; being non-toxic; and free from poorly degradable polymeric surfactants and chromates that can cause hexavalent chromium pollution, guaranteeing no harm to operators or the environment; and ensuring a simple and safe cleaning operation that effectively reduces the risks of flammability and explosion during rocket painting. Summary of the Invention

[0004] This invention provides a cleaning agent for rocket coating and its preparation method, which solves the problems of existing cleaning agents for rocket shell coating, such as low safety factor for operators and the environment, low efficiency in removing pollutants, easy damage to aluminum substrate, and complex preparation.

[0005] To solve the above-mentioned technical problems, the first aspect of the present invention provides a carrier rocket coating cleaning agent, the cleaning agent comprising the following components in mass percentage: 10%-20% decafluoro-3-methoxy-2-trifluoromethylpentane, 50%-70% hydrofluoroether, 2%-20% fluoroalcohol, 1%-5% cyclohexane, and 1%-5% cosolvent.

[0006] Furthermore, the hydrofluoroether comprises one or more of 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, ethyl nonafluorobutyl ether, 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone or perfluorobutyl methyl ether.

[0007] Furthermore, the fluorohydrin includes one or more of trifluoroacetaldehyde acetal ...

[0008] Furthermore, the cosolvent comprises the following components in weight percentages: 25%-45% 4,5,5-trifluoro-4-pentenoic acid, 35%-70% anisole, and 5%-20% diethanolamine.

[0009] Furthermore, the cleaning agent comprises the following components in weight percentages: 13%-18% decafluoro-3-methoxy-2-trifluoromethylpentane, 65%-67% hydrofluoroether, 10%-12% fluoroalcohol, 3%-5% cyclohexane, and 2%-5% cosolvent.

[0010] Furthermore, the hydrofluoroether is one of 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, perfluorobutyl methyl ether, or ethyl nonafluorobutyl ether.

[0011] Furthermore, the cosolvent comprises the following components in weight percentages: 30%-40% 4,5,5-trifluoro-4-pentenoic acid, 50%-60% anisole, and 10%-20% diethanolamine.

[0012] Secondly, a method for preparing a carrier rocket coating cleaning agent is provided, comprising the following steps:

[0013] S1. Preparation of cosolvents;

[0014] S2. Mix decafluoro-3-methoxy-2-trifluoromethylpentane, hydrofluoroether and fluoroalcohol, and stir until homogeneous to obtain the base solution;

[0015] S3. Add cyclohexane and the cosolvent obtained in step S1 to the base liquid, stir evenly, and obtain the cleaning agent.

[0016] Furthermore, the preparation of the co-solvent includes:

[0017] S1-1. Mix 4,5,5-trifluoro-4-pentenoic acid and anisole evenly to obtain solution A;

[0018] S1-2. Add diethanolamine to solution A, heat and stir until the reaction is complete, and distill off the solvent under reduced pressure to obtain a co-solvent.

[0019] Furthermore, the temperature during the preparation processes of steps S2 and S3 is kept constant, and the temperature is 20℃-30℃.

[0020] The advantages and beneficial effects of this invention are:

[0021] 1. This invention uses hydrofluoroether, which is safe, stable, and has an ODP (Ozone Depletion Potential) value of 0, as the main solvent, combined with fluorohydrin and co-solvent. The selected components do not contain heavy metals, strong alkalis, nitrites, phosphorus, amides, or highly toxic and volatile organic solvents such as chlorinated hydrocarbons, phenols, and ketones. It is physiologically harmless, mild in nature, has no flash point, and is easily volatile. It has the functions of cleaning dirt and protecting coatings, high cleaning power, safety, environmental protection, energy saving, and an ODP value of 0.

[0022] 2. It possesses excellent cleaning and coating-promoting effects, rapidly and thoroughly removing various light and heavy oil stains and complex dirt from the rocket shell surface. The cleaning effect is outstanding, long-lasting, and effectively improves coating adhesion. It does not damage the aluminum-based material of the shell. The preparation method is simple and easy to implement, with a high safety factor during cleaning. Waste liquid can be recycled, making it economical, safe, energy-saving, and environmentally friendly. It effectively solves the problems of traditional cleaning agents, such as high toxicity, strong odor, low flash point, and environmental damage. Detailed Implementation

[0023] The specific implementation schemes of the present invention will be described in detail and clearly below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are mostly within the scope of protection of the present invention.

[0024] Example 1

[0025] A launch vehicle coating cleaner comprises 13% decafluoro-3-methoxy-2-trifluoromethylpentane, 67% 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, 12% difluoroacetaldehyde acetal ...

[0026] 13% decafluoro-3-methoxy-2-trifluoromethylpentane, 67% 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, and 12% difluoroacetaldehyde hemiacetal were added to a reaction vessel. Stirring was started, and the temperature was controlled at 20℃-30℃. Stirring was continued for 60 minutes to ensure complete dissolution and homogeneity of the raw materials in the reaction vessel. 3% cyclohexane and 5% co-solvent were added, maintaining a constant reaction vessel temperature throughout the preparation process. Stirring was continued for 30 minutes until homogeneous, thus obtaining the rocket shell cleaning agent.

[0027] The co-solvent comprises 30.8% 4,5,5-trifluoro-4-pentenoic acid, 58.6% anisole, and 10.6% diethanolamine. The 30.8% 4,5,5-trifluoro-4-pentenoic acid and 58.6% anisole are added to a reaction vessel, and the temperature is controlled at 60-70℃. After stirring and mixing for 10-15 minutes, solution A is obtained. Then, 10.6% diethanolamine is added to the reaction vessel, and after stirring evenly, the temperature is raised to 130-150℃, and the reaction is stirred for 120-180 minutes. The reaction ends when no more exothermic reactions occur. The solvent, 4,5,5-trifluoro-4-pentenoic acid diethanolamine ester, is distilled off under reduced pressure. After completion, the mixture is cooled to room temperature to obtain the aforementioned co-solvent.

[0028] Example 2:

[0029] A launch vehicle coating cleaning agent comprises 18% decafluoro-3-methoxy-2-trifluoromethylpentane, 65% perfluorobutyl methyl ether, 10% trifluoroacetaldehyde acetal ...

[0030] 18% decafluoro-3-methoxy-2-trifluoromethylpentane, 65% perfluorobutyl methyl ether, and 10% trifluoroacetaldehyde acetal ether were added to a reaction vessel. Stirring was started, and the temperature was controlled at 20℃-30℃. Stirring was continued for 60 minutes to ensure complete dissolution and homogeneity of the raw materials in the reaction vessel. 5% cyclohexane and 2% co-solvent were added, maintaining a constant reaction vessel temperature throughout the preparation process. Stirring was continued for 30 minutes until homogeneous, thus obtaining the rocket shell cleaning agent.

[0031] The co-solvent comprises 30.8% 4,5,5-trifluoro-4-pentenoic acid, 58.6% anisole, and 10.6% diethanolamine. The 30.8% 4,5,5-trifluoro-4-pentenoic acid and 58.6% anisole are added to a reaction vessel, and the temperature is controlled at 60-70℃. After stirring and mixing for 10-15 minutes, solution A is obtained. Then, 10.6% diethanolamine is added to the flask, and after stirring evenly, the temperature is raised to 130-150℃, and the reaction is stirred for 120-180 minutes. The reaction ends when no more exothermic reactions occur. The solvent 4,5,5-trifluoro-4-pentenoic acid diethanolamine ester is distilled off under reduced pressure. After completion, the mixture is cooled to room temperature to obtain the aforementioned co-solvent.

[0032] Example 3:

[0033] A launch vehicle coating cleaner comprises 14% decafluoro-3-methoxy-2-trifluoromethylpentane, 65% ethyl nonafluorobutyl ether, 12% pentafluoropropanol, 5% cyclohexane and 4% cosolvent.

[0034] Add 14% decafluoro-3-methoxy-2-trifluoromethylpentane, 65% ethyl nonafluorobutyl ether, and 12% pentafluoropropanol to a reaction vessel, start stirring, and control the temperature at 20℃-30℃. Stir for 60 minutes to ensure the raw materials in the reaction vessel are completely dissolved and mixed evenly. Add 5% cyclohexane and 4% co-solvent, maintaining a constant reaction vessel temperature throughout the production process. Stir for 30 minutes until evenly mixed to obtain the rocket shell cleaning agent.

[0035] The co-solvent comprises 30.8% 4,5,5-trifluoro-4-pentenoic acid, 58.6% anisole, and 10.6% diethanolamine. The 30.8% 4,5,5-trifluoro-4-pentenoic acid and 58.6% anisole are added to a reaction vessel, and the temperature is controlled at 60-70℃. After stirring and mixing for 10-15 minutes, solution A is obtained. Then, 10.6% diethanolamine is added to the flask, and after stirring evenly, the temperature is raised to 130-150℃, and the reaction is stirred for 120-180 minutes. The reaction ends when no more exothermic reactions occur. The solvent 4,5,5-trifluoro-4-pentenoic acid diethanolamine ester is distilled off under reduced pressure. After completion, the mixture is cooled to room temperature to obtain the co-solvent.

[0036] The cleaning agents in Examples 1-3 use hydrofluoroether as the main solvent, and decafluoro-3-methoxy-2-trifluoromethylpentane is used to replace part of the hydrofluoroether to reduce the preparation cost. Fluorohydrins have unique chemical stability, corrosion resistance, flame retardancy, hydrophobicity, oleophobicity, and antifouling properties. In this invention, fluorohydrins are used to promote the dissolution of hydrofluoroether by cyclohexane, and increase the cleaning agent's ability to dissolve polar oil stains by acting as a co-solvent. Furthermore, since the co-solvent evaporates relatively slowly, it provides short-term protection. Therefore, the components in the cleaning agent of this invention work together synergistically.

[0037] Example 4: Performance Test of a Launch Vehicle Coating Cleaning Agent

[0038] The density, flash point, and detergency of the cleaning agents prepared in Examples 1-3 were tested respectively. Density was determined according to national standard (GB / T4472), flash point according to national standard (GB / T 261), and detergency and corrosivity were tested according to standard Q / 12NK 5119. Control Example 1 and Control Example 2 were set up. Control Example 1 was gasoline; Control Example 2 was the aviation component cleaning agent specifically disclosed in the published patent titled "A Cleaning Agent for Aviation Parts and Preparation Method" (application number: 201611223068.1). Control Example 2 had problems such as slow evaporation, a flash point, and the presence of ethylene glycol butyl ether, which is harmful to the human body. Specific results for the blank examples are shown in Table 1.

[0039] Table 1. Results of Cleaning Agent Performance Tests

[0040]

[0041] This invention uses hydrofluoroether, a safe and stable solvent with an ODP (Ozone Depletion Potential) of 0, as the main solvent, combined with fluorohydrins and co-solvents. The selected components are free of heavy metals, strong alkalis, nitrites, phosphorus, amines, amides, and highly toxic and volatile organic solvents such as chlorinated hydrocarbons, phenols, and ketones; they are physiologically harmless, mild in nature, have no flash point, and are easily volatile. It possesses cleaning and short-term protective functions (such as cleaning dirt and protecting coatings), high cleaning power, safety, environmental friendliness, energy saving, and an ODP of 0. It exhibits excellent cleaning and coating-promoting effects, rapidly and thoroughly removing various light and heavy oil stains and complex dirt from the surface of rocket casings. The cleaning effect is excellent, and the surface tension of the cleaning agent is very low, effectively improving coating adhesion. It does not damage the aluminum-based material of the casing. The preparation method is simple and easy to implement, with a high safety factor during cleaning, and the waste liquid can be recycled, making it economical, safe, energy-saving, and environmentally friendly. It effectively solves the problems of high toxicity, strong odor, low flash point, and environmental damage associated with traditional cleaning agents.

Claims

1. A carrier rocket coating cleaning agent, characterized in that: The cleaning agent comprises the following components by weight percentage: 10%-20% decafluoro-3-methoxy-2-trifluoromethylpentane, 50%-70% hydrofluoroether, 2%-20% fluoroalcohol, 1%-5% cyclohexane, and 1%-5% cosolvent; The preparation of the co-solvent includes: S1-1. Mix 4,5,5-trifluoro-4-pentenoic acid and anisole evenly to obtain solution A; S1-2. Diethanolamine is added to solution A, heated and stirred until the reaction is complete, and then distilled off under reduced pressure to obtain a cosolvent. The hydrofluoroether is one of 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, perfluorobutyl methyl ether, or ethyl nonafluorobutyl ether. The cleaning agent has no flash point when tested according to GB / T 261, and the corrosion amount on 2A12 aluminum alloy is ≤0.6mg when tested according to Q / 12NK 5119 standard.

2. The rocket coating cleaning agent according to claim 1, characterized in that, The fluoroalcohols include one or more of trifluoroacetaldehyde halogenate, difluoroacetaldehyde halogenate, or pentafluoropropanol.

3. The rocket coating cleaning agent according to claim 1, characterized in that, The mass percentages of 4,5,5-trifluoro-4-pentenoic acid, anisole, and diethanolamine in the cosolvent are: 4,5,5-trifluoro-4-pentenoic acid 25%-45%, anisole 35%-70%, and diethanolamine 5%-20%.

4. The rocket coating cleaning agent according to claim 1, characterized in that, The cleaning agent comprises the following components by weight percentage: 13%-18% decafluoro-3-methoxy-2-trifluoromethylpentane, 65%-67% hydrofluoroether, 10%-12% fluoroalcohol, 3%-5% cyclohexane, and 2%-5% cosolvent.

5. The rocket coating cleaning agent according to claim 3, characterized in that, The mass percentages of 4,5,5-trifluoro-4-pentenoic acid, anisole, and diethanolamine in the cosolvent are: 30%-40% 4,5,5-trifluoro-4-pentenoic acid, 50%-60% anisole, and 10%-20% diethanolamine.

6. A method for preparing a launch vehicle coating cleaning agent according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Preparation of cosolvents; S2. Mix decafluoro-3-methoxy-2-trifluoromethylpentane, hydrofluoroether and fluoroalcohol, and stir until homogeneous to obtain the base solution; S3. Add cyclohexane and the cosolvent obtained in step S1 to the base liquid, stir evenly, and obtain the cleaning agent.

7. The method for preparing a carrier rocket coating cleaning agent according to claim 6, characterized in that, The temperature is kept constant during the preparation processes of steps S2 and S3, which is 20℃-30℃.

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