A high-strength coating for a gas cylinder, a method for preparing the coating, and a hydrogen cylinder containing the coating.

Abstract

This invention relates to the field of gas cylinder coating technology, specifically to a high-strength coating for gas cylinders, a preparation method thereof, and a hydrogen cylinder containing the same. The high-strength coating, by weight, comprises: 30-50 parts modified epoxy resin, 5-10 parts hollow glass microspheres, 1-5 parts film-forming aid, 5-10 parts filler, 5-10 parts toughening agent, 25-35 parts curing agent, 5-10 parts diluent, 0.1-0.5 parts defoamer, and 0.5-1 part dispersant. The modified epoxy resin is a carbon nanotube-modified epoxy resin. The filler is modified nano-silica. The preparation method includes the following steps: dispersing the modified epoxy resin and hollow glass microspheres, then slowly adding the filler and toughening agent while stirring to obtain an intermediate material; sequentially adding the remaining components to the intermediate material and stirring until uniform to obtain the finished coating. It exhibits excellent scratch resistance and adhesion, resulting in superior overall performance of the gas cylinder liner.

Description

Technical Field

[0001] This invention relates to the field of gas cylinder coating technology, and more specifically, to a high-strength coating for gas cylinders, a preparation method thereof, and a hydrogen cylinder containing the same. Background Technology

[0002] High-pressure gas cylinders are core energy storage components in fields such as hydrogen energy storage, aerospace, and new energy vehicles. Their structural safety and long-term service stability directly determine the operational safety and service life of related equipment. Currently, most high-pressure gas cylinders widely used in the industry adopt a structural design of "metal liner-coating-fiber winding composite layer". The metal liner provides airtight load-bearing capacity, the fiber winding composite layer provides reinforced protection, and the coating, as a key transition layer between the liner and the fiber layer, undertakes multiple functions such as corrosion prevention, stress transfer, and interface bonding.

[0003] During the transportation, storage, and use of high-pressure gas cylinders, the coating is often damaged or partially peeled off due to factors such as friction, collision, and vibration. Once the coating fails, it will directly cause the following technical problems: (1) the metal liner is exposed to a corrosive environment, inducing stress corrosion cracking and reducing fatigue life; (2) the coating and fiber winding layer debond at the interface, leading to stress transmission failure and structural delamination. Therefore, the adhesion between the coating and the metal substrate is the basis for ensuring the long-term stable service of the coating and is also a key technical indicator that determines the safety of the high-pressure gas cylinder throughout its entire life cycle.

[0004] Existing high-pressure gas cylinder coating technologies mainly include organic coatings and inorganic coatings. Organic coatings, such as epoxy resin and phenolic resin, have good flexibility and ease of construction, but are prone to hydrogen embrittlement and permeation degradation in high-pressure hydrogen environments. Inorganic coatings, such as ceramic coatings and metal oxide coatings, are brittle and have poor compatibility with the thermal expansion coefficient of the metal substrate, making them prone to cracking and peeling under thermal cycling conditions. Summary of the Invention

[0005] Based on the above problems, the purpose of this invention is to provide a high-strength coating for gas cylinders, a preparation method thereof, and a hydrogen cylinder containing the same, which has excellent scratch resistance, adhesion, and strength, resulting in excellent overall performance of the gas cylinder liner.

[0006] The embodiments of the present invention are achieved through the following technical solutions:

[0007] A high-strength coating for gas cylinders, by weight, comprises: 30-50 parts modified epoxy resin, 5-10 parts hollow glass microspheres, 1-5 parts film-forming aid, 5-10 parts filler, 5-10 parts toughening agent, 25-35 parts curing agent, 5-10 parts diluent, 0.1-0.5 parts defoamer, and 0.5-1 part dispersant; wherein the modified epoxy resin is a carbon nanotube modified epoxy resin; and the filler is modified nano silica.

[0008] In addition, the present invention also provides a method for preparing the above-mentioned high-strength coating for gas cylinders, comprising the following steps: S1. Disperse the modified epoxy resin and hollow glass microspheres, then slowly add filler and toughening agent while stirring to obtain intermediate material; S2. Add the remaining components to the intermediate material in sequence and stir evenly to obtain the finished coating.

[0009] Finally, the present invention also provides a hydrogen cylinder comprising the aforementioned high-strength coating.

[0010] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects: 1. In this invention, the alkoxy group of the silane coupling agent is hydrolyzed to generate silanol, which can dehydrate and condense with the hydroxyl groups on the surface of nano-silica to form a stable Si-O-Si bond; at the same time, phosphate ester groups are introduced, which can form coordination bonds with the surface of the metal liner. In this way, an aminosilane chain is grafted onto one end of the nano-silica surface, and the other end contains both epoxy and phosphate groups. It reacts chemically with epoxy resin to achieve inorganic-organic interface bridging, so that the nano-silica-epoxy, nano-silica-metal, and epoxy-metal interfaces are all highly bonded.

[0011] 2. The modified epoxy resin and filler of this invention have greatly improved compatibility with the metal matrix, resulting in high-strength bonding at the interfaces of nano-silica-epoxy resin, nano-silica-metal, and epoxy resin-metal. Furthermore, the polar functional groups on the surface of the modified filler can undergo hydrolysis and condensation reactions with the silane coupling agent added to the modified resin system to form stable chemical bonds. Thus, under the bridging effect of the modified epoxy resin and filler, a chemical bridging structure of "metal matrix-filler-coupling agent-resin" is constructed, transforming the coating and the inner liner matrix into a stable chemical bond, thereby significantly improving the bonding strength between them. This results in a coating with excellent scratch resistance, adhesion, and strength, leading to superior overall performance of the gas cylinder inner liner. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0013] The following is a detailed description of a high-strength coating for gas cylinders, its preparation method, and a hydrogen cylinder containing the same, provided by embodiments of the present invention.

[0014] A high-strength coating for gas cylinders, by weight, comprises: 30-50 parts modified epoxy resin, 5-10 parts hollow glass microspheres, 1-5 parts film-forming aid, 5-10 parts filler, 5-10 parts toughening agent, 25-35 parts curing agent, 5-10 parts diluent, 0.1-0.5 parts defoamer, and 0.5-1 part dispersant; wherein the modified epoxy resin is an epoxy resin modified with nanofillers. The filler is modified nano-silica, and its preparation method is as follows: 1. Vacuum-dried fumed silica nanoparticles were dried at 100~150℃ and -0.05~-0.1MPa for 5~8 hours. 2. Add the silane coupling agent hydrolysate to the treated nano-silica and ultrasonically disperse for 10-30 min. Then, stir and react at 50-80℃ under a nitrogen atmosphere for 1-3 h. Afterward, centrifuge, wash, dry, and grind through a 200-mesh sieve to obtain functional nano-silica. Dry under vacuum at 60-100℃ and -0.05--0.1 MPa for 10-15 h. The preparation method of the silane coupling agent hydrolysate is as follows: mix 90-95% anhydrous ethanol and 5-10% deionized water, adjust the pH of the system to 4.5-5.5 with glacial acetic acid, add 1-3% silane coupling agent, and stir and hydrolyze for 5-10 min. The mass ratio of the silane coupling agent hydrolysate to nano-silica is 10-15:1. 3. After mixing phosphate methacrylate with functional nano silica, add an organic solvent (such as anhydrous ethanol or acetone) and triethylamine, and ultrasonically disperse for 10-30 min. Then, stir and react at 50-80℃ under a nitrogen atmosphere for 3-8 h. Afterward, centrifuge, wash, dry, and grind through a 200-mesh sieve to obtain modified nano silica. During drying, vacuum dry at 50-80℃ and -0.05--0.1 MPa for 20-25 h. The mass ratio of the functional nano silica, phosphate methacrylate, and triethylamine is 100:3-8:0.5-1.

[0015] To address the poor compatibility between nano-silica and epoxy resin systems and metal matrices, the inventors performed surface modification on nano-silica to improve the compatibility of the dual interfaces. After hydrolyzing the alkoxy groups of the silane coupling agent to generate silanols, these silanols can undergo dehydration condensation with the hydroxyl groups on the surface of nano-silica, forming stable Si-O-Si bonds. Simultaneously, phosphate ester groups are introduced, which can form coordination bonds with the surface of the metal liner. Thus, an aminosilane chain is grafted onto one end of the nano-silica surface, while the other end contains both epoxy and phosphate groups, reacting chemically with the epoxy resin to achieve inorganic-organic interface bridging. This results in high-strength bonding at the nano-silica-epoxy, nano-silica-metal, and epoxy-metal interfaces.

[0016] The modified epoxy resin is prepared as follows: 1. Carbon nanotubes and benzimidazole derivatives are added to a silane coupling agent, ultrasonically dispersed for 0.5-1 h, and then dried at 50-80℃ to obtain surface-modified carbon nanotubes. 2. Add reactive diluent BGE to epoxy resin (such as bisphenol F type epoxy resin, E-51 epoxy resin), stir and mix for 10~30 min, and then heat to 50~70℃ to obtain pretreated resin. 3. Add the surface-modified carbon nanotubes to the pretreated resin, disperse at high speed for 0.5-1h, add the toughening agent, continue dispersion for 10-30min, cool to room temperature, add the curing agent, stir at low speed for 5-10min, and degas under vacuum for 10-30min to obtain the modified epoxy resin.

[0017] Preferably, the mass ratio of the carbon nanotubes to the benzimidazole derivative is 1:1~3; and the mass ratio of the surface-modified nanofiller to the pretreated resin is 1:10~30.

[0018] After the coating of this invention is applied to the inner liner, subsequent winding of carbon fiber and glass fiber layers can be carried out. After winding, the carbon fiber and glass fiber layers are combined with the modified epoxy resin. These polar functional groups undergo nucleophilic reactions with the epoxy groups and hydroxyl groups in the epoxy resin molecules to form stable covalent bonds. At the same time, the polar functional groups on the surface of the modified filler can also undergo hydrolysis and condensation reactions with the silane coupling agent added to the modified resin system to form stable chemical bonds. In this way, a chemical bridging structure of "metal matrix-filler-coupling agent-resin" is constructed, which transforms the coating and the inner liner matrix into a stable chemical bond, thereby significantly improving the bonding strength between the coating and the inner liner. Even in a high-pressure hydrogen environment, it is not easy to undergo hydrogen embrittlement and permeation degradation.

[0019] Furthermore, the film-forming aid is selected from alcohol ethers such as ethylene glycol butyl ether, propylene glycol methyl ether, and dipropylene glycol methyl ether, or alcohol esters such as dodecyl alcohol ester and hexadecyl alcohol ester; The toughening agent selected includes: carboxyl-terminated butadiene-acrylonitrile rubber, amino-terminated butadiene-acrylonitrile rubber, liquid polysulfide rubber, polyurethane prepolymer, polyetherimide, etc. The curing agent selected includes: ethylenediamine, diethylenetriamine, triethylenetetramine, phthalic anhydride, trimellitic anhydride, maleic anhydride, etc. The diluent selected is: butyl glycidyl ether, phenyl glycidyl ether, 1,4-butanediol diglycidyl ether, trimethylolpropane triglycidyl ether, etc. The defoamer is selected from organosilicon defoamers, such as: polydimethylsiloxane, polyether-modified polysiloxane, fluorosiloxane; or polyethers, such as: polyoxypropylene, polyoxyethylene polyoxypropylene glycerol ether, polyoxypropylene glycerol ether. The dispersant selected is: sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium oleate, sodium stearate, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium chloride, or fatty alcohol polyoxyethylene ether.

[0020] A method for preparing a high-strength coating for gas cylinders includes the following steps: S1. Disperse the modified epoxy resin and hollow glass microspheres at 1500~1800r / min for 30~60min; then slowly add the filler and toughening agent and stir at a temperature of 50-55℃ for 40~50min to obtain the intermediate material. S2. Add the remaining components to the intermediate material in sequence and continue stirring for 40-50 minutes to obtain the finished coating.

[0021] The present invention also provides a hydrogen cylinder comprising the above-described high-strength coating.

[0022] Example 1 This application provides a high-strength coating for gas cylinders, comprising, by weight: 40 parts modified epoxy resin, 6 parts hollow glass microspheres, 3 parts film-forming aid ethylene glycol butyl ether, 8 parts filler, 7 parts toughening agent polyetherimide, 30 parts curing agent ethylenediamine, 7 parts diluent butyl glycidyl ether, 0.3 parts defoamer polydimethylsiloxane, and 0.7 parts dispersant sodium dodecyl sulfate; The preparation method of the modified nano-silica filler is as follows: A1. Vacuum-dried fumed silica nanoparticles were dried at 120℃ and -0.08MPa for 6 hours. A2. Mix 95% anhydrous ethanol and 5% deionized water, adjust the pH of the system to 5 with glacial acetic acid, add 2% silane coupling agent KH560, and stir for 10 min to obtain silane coupling agent hydrolysate. Add this hydrolysate to the nano-silica treated in A1, and ultrasonically disperse for 20 min. Then, stir and react at 70℃ under a nitrogen atmosphere for 2 h. Afterward, centrifuge, wash, dry, and grind through a 200-mesh sieve to obtain functional nano-silica. Dry at 80℃ and -0.08MPa vacuum for 12 h. The mass ratio of the silane coupling agent hydrolysate to nano-silica is 12:1. A3. Phosphate methacrylate was mixed with functional nano-silica, anhydrous acetone and triethylamine were added, and the mixture was ultrasonically dispersed for 20 min. Then, the mixture was stirred and reacted at 60 °C under a nitrogen atmosphere for 5 h. After that, the mixture was centrifuged, washed, dried, and ground through a 200-mesh sieve to obtain modified nano-silica. During drying, the mixture was vacuum dried at 60 °C and -0.08 MPa for 24 h. The mass ratio of the functional nano-silica, phosphate methacrylate and triethylamine was 100:5:0.7.

[0023] The modified epoxy resin is prepared as follows: B1. Carbon nanotubes and benzimidazole derivatives were added to silane coupling agent KH560, ultrasonically dispersed for 0.5 h, and then dried at 70 °C to obtain surface-modified carbon nanotubes; the mass ratio of carbon nanotubes to benzimidazole derivatives was 1:2. B2. Add reactive diluent BGE to E-51 epoxy resin, stir and mix for 20 minutes, and then heat to 60℃ to obtain pretreated resin. B3. Surface-modified carbon nanotubes are added to the pretreated resin and dispersed by high-speed shearing for 1 hour. Then, toughening agent polyetherimide is added and dispersion is continued for 20 minutes. After cooling to room temperature, curing agent ethylenediamine is added, and the mixture is stirred at low speed for 10 minutes and vacuum degassed for 20 minutes to obtain the modified epoxy resin. The mass ratio of the surface-modified nanofiller to the pretreated resin is 1:20.

[0024] This embodiment also provides a method for preparing a high-strength coating for gas cylinders, including the following steps: S1. Disperse the modified epoxy resin and hollow glass microspheres at 1600 r / min for 40 min; then slowly add the filler and toughening agent and stir at 50℃ for 45 min to obtain the intermediate material. S2. Add the remaining components to the intermediate material in sequence and continue stirring for 45 minutes to obtain the finished coating.

[0025] The present invention also provides a hydrogen cylinder comprising the above-described high-strength coating.

[0026] Example 2 The difference between this embodiment and Embodiment 1 is that: a high-strength coating for gas cylinders, by weight, comprises: 38 parts modified epoxy resin, 6 parts hollow glass microspheres, 3 parts film-forming aid dodecyl alcohol ester, 7 parts filler, 9 parts toughening agent polyurethane prepolymer, 28 parts curing agent maleic anhydride, 8 parts diluent phenyl glycidyl ether, 0.3 parts defoamer polyoxypropylene, and 0.7 parts dispersant cetyltrimethylammonium bromide.

[0027] Example 3 The difference between this embodiment and Embodiment 1 is that: a high-strength coating for gas cylinders, by weight, comprises: 45 parts modified epoxy resin, 7 parts hollow glass microspheres, 4 parts film-forming aid dipropylene glycol methyl ether, 7 parts filler, 8 parts toughening agent liquid polysulfide rubber, 26 parts curing agent triethylenetetramine, 8 parts diluent 1,4-butanediol diglycidyl ether, 0.2 parts defoamer polyoxyethylene polyoxypropylene glycerol ether, and 0.8 parts dispersant sodium oleate.

[0028] Example 4 The difference between this embodiment and Embodiment 1 is that: The preparation method of the modified nano-silica filler is as follows: A1. Vacuum-dried fumed silica nanoparticles were dried at 130℃ and -0.07MPa for 7 hours. A2. Mix 90% anhydrous ethanol and 10% deionized water, adjust the pH of the system to 5 with glacial acetic acid, add 3% silane coupling agent KH560, and stir for 5 minutes to obtain silane coupling agent hydrolysate. Add this hydrolysate to the nano-silica treated in A1, and ultrasonically disperse for 25 minutes. Then, stir and react for 1 hour at 60°C under a nitrogen atmosphere. Afterward, centrifuge, wash, dry, and grind through a 200-mesh sieve to obtain functional nano-silica. Dry at 80°C and -0.07MPa vacuum for 12 hours. The mass ratio of the silane coupling agent hydrolysate to nano-silica is 13:1. A3. After mixing phosphate methacrylate with functional nano silica, anhydrous acetone and triethylamine were added, and the mixture was ultrasonically dispersed for 25 min. Then, the mixture was stirred and reacted at 70 °C under a nitrogen atmosphere for 6 h. Afterward, the mixture was centrifuged, washed, dried, and ground through a 200-mesh sieve to obtain modified nano silica. During drying, the mixture was vacuum dried at 70 °C and -0.09 MPa for 24 h. The mass ratio of the functional nano silica, phosphate methacrylate, and triethylamine was 100:7:0.5.

[0029] Example 5 The difference between this embodiment and Embodiment 1 is that: The modified epoxy resin is prepared as follows: B1. Carbon nanotubes and benzimidazole derivatives were added to silane coupling agent KH560, ultrasonically dispersed for 0.5 h, and then dried at 70 °C to obtain surface-modified carbon nanotubes; the mass ratio of carbon nanotubes to benzimidazole derivatives was 1:3. B2. Add reactive diluent BGE to E-51 epoxy resin, stir and mix for 30 minutes, and then heat to 50°C to obtain pretreated resin. B3. Surface-modified carbon nanotubes are added to the pretreated resin and dispersed by high-speed shearing for 1 hour. Then, toughening agent polyetherimide is added and dispersion is continued for 30 minutes. After cooling to room temperature, curing agent ethylenediamine is added, and the mixture is stirred at low speed for 10 minutes. Vacuum degassing is then performed for 30 minutes to obtain the modified epoxy resin. The mass ratio of the surface-modified nanofiller to the pretreated resin is 1:15.

[0030] Comparative Example 1 The difference between this comparative example and Example 1 is that: A high-strength coating for gas cylinders, by weight, comprises: 10 parts modified epoxy resin, 30 parts hollow glass microspheres, 8 parts film-forming aid ethylene glycol butyl ether, 2 parts filler, 5 parts toughening agent polyetherimide, 25 parts curing agent ethylenediamine, 8 parts diluent butyl glycidyl ether, 0.1 parts defoamer polydimethylsiloxane, and 0.5 parts dispersant sodium dodecyl sulfate.

[0031] Comparative Example 2 The difference between this comparative example and Example 1 is that: The epoxy resin is E-51 epoxy resin, meaning it has not undergone any modification treatment.

[0032] Comparative Example 3 The difference between this comparative example and Example 1 is that the filler used is ordinary nano-silica, that is, no modification treatment was performed.

[0033] Experimental Example 1 The adhesion between the coatings of each embodiment and the inner liner substrate was tested according to the pull-off method in GB / T 5210; and the tests were conducted according to the test method in GB / T 42610-2023 under combined thermal cycling and hydrogen cycling conditions (cyclic charging and discharging of hydrogen between 15°C and 55°C); the scratch resistance test was performed on the coatings prepared in each embodiment and the comparative embodiment after they were applied to the inner liner according to GB / T 9279.1-2015; and the adhesion test was performed on the coatings prepared in each embodiment and the comparative embodiment after they were applied to the inner liner according to GB / T 9286-2021. In Table 1, the enhanced state represents whether bubbling, delamination, or peeling occurs after thermal / hydrogen cycling. Table 1 - Performance Comparison of Various Examples and Comparative Examples

[0034] As shown in Table 1, compared to the comparative examples, the coating in this embodiment, with appropriate proportions and modifications to both the epoxy resin and filler, exhibits superior scratch resistance, adhesion, and strength, resulting in excellent overall performance of the gas cylinder liner. This is primarily due to the significantly improved compatibility between the modified epoxy resin and filler and the metal matrix, leading to high-strength bonding at the interfaces of nano-silica-epoxy resin, nano-silica-metal, and epoxy resin-metal. Furthermore, the bridging effect of the modified epoxy resin and filler constructs a chemical bridging structure of "coating-coupling agent-resin," transforming the coating, carbon fiber layer, and glass fiber layer from simple physical adsorption to a stable chemical bond, thereby significantly enhancing the bonding strength between them and the liner.

[0035] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-strength coating for gas cylinders, characterized in that, By weight, the composition includes: 30-50 parts modified epoxy resin, 5-10 parts hollow glass microspheres, 1-5 parts film-forming aid, 5-10 parts filler, 5-10 parts toughening agent, 25-35 parts curing agent, 5-10 parts diluent, 0.1-0.5 parts defoamer, and 0.5-1 part dispersant; the modified epoxy resin is a carbon nanotube modified epoxy resin; the filler is modified nano silica.

2. The high-strength coating for gas cylinders according to claim 1, characterized in that, By weight, it includes: 30-40 parts modified epoxy resin, 5-8 parts hollow glass microspheres, 1-3 parts film-forming aid, 7-10 parts filler, 5-8 parts toughening agent, 30-35 parts curing agent, 7-10 parts diluent, 0.1-0.3 parts defoamer, and 0.5-1 parts dispersant.

3. The high-strength coating for gas cylinders according to claim 1 or 2, characterized in that, The modified epoxy resin is prepared as follows: A1. Carbon nanotubes and benzimidazole derivatives were added to a silane coupling agent, ultrasonically dispersed, and then dried to obtain surface-modified carbon nanotubes. A2. Add reactive diluent to epoxy resin, stir, and heat to obtain pretreated resin; A3. Surface-modified carbon nanotubes are added to the pretreated resin, dispersed by high-speed shearing, toughening agent is added, dispersion is continued for a period of time, cooled to room temperature, curing agent is added, and after stirring and vacuum degassing, the modified epoxy resin is obtained.

4. The high-strength coating for gas cylinders according to claim 3, characterized in that, In A1, the mass ratio of the carbon nanotubes to the benzimidazole derivative is 1:1~3; in A3, the mass ratio of the surface-modified carbon nanotubes to the pretreated resin is 1:10~30.

5. The high-strength coating for gas cylinders according to claim 1 or 2, characterized in that, The modified nano-silica is prepared as follows: B1. Vacuum dry the nano-silica for a period of time and set aside. B2. Add the hydrolysate of the silane coupling agent to the nano-silica treated in B1, disperse it by ultrasonication, and then stir and react for a period of time under nitrogen atmosphere protection. The product is then centrifuged, washed, dried, ground, and sieved to obtain functional nano-silica. B3. After mixing phosphate methacrylate with functional nano silica, add organic solvent and triethylamine, disperse ultrasonically, and then stir and react for a period of time under nitrogen atmosphere protection. After centrifugation, washing, drying, grinding, and sieving, modified nano-silica is obtained.

6. The high-strength coating for gas cylinders according to claim 5, characterized in that, In B2, the preparation method of the silane coupling agent hydrolysate is as follows: after mixing 90-95% anhydrous ethanol and 5-10% deionized water, the pH of the system is adjusted to 4.5-5.5, 1-3% silane coupling agent is added, and the mixture is stirred and hydrolyzed for 5-10 minutes to obtain the solution.

7. The high-strength coating for gas cylinders according to claim 5, characterized in that, In B2, the mass ratio of the silane coupling agent hydrolysate to nano-silica is 10~15:1; in B3, the mass ratio of the functional nano-silica, phosphate methacrylate, and triethylamine is 100:3~8:0.5~1.

8. The high-strength coating for gas cylinders according to claim 1 or 2, characterized in that, The film-forming aid is one or more of the following: ethylene glycol butyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, dodecyl alcohol ester, and hexadecyl alcohol ester; the toughening agent is one or more of the following: carboxyl-terminated butadiene-acrylonitrile rubber, amino-terminated butadiene-acrylonitrile rubber, liquid polysulfide rubber, polyurethane prepolymer, and polyetherimide. The curing agent is one or more of the following: ethylenediamine, diethylenetriamine, triethylenetetramine, phthalic anhydride, trimellitic anhydride, and maleic anhydride. The diluent is one or more of the following: butyl glycidyl ether, phenyl glycidyl ether, 1,4-butanediol diglycidyl ether, and trimethylolpropane triglycidyl ether. The defoamer is one or more of the following: polydimethylsiloxane, polyether-modified polysiloxane, fluorosiloxane, polyoxypropylene, polyoxyethylene polyoxypropylene glycerol ether, and polyoxypropylene glycerol ether. The dispersant is one or more of the following: sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium oleate, sodium stearate, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium chloride, and fatty alcohol polyoxyethylene ether.

9. A method for preparing a high-strength coating for gas cylinders according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Disperse the modified epoxy resin and hollow glass microspheres, then slowly add filler and toughening agent while stirring to obtain intermediate material; S2. Add the remaining components to the intermediate material in sequence and stir evenly to obtain the finished coating.

10. A hydrogen cylinder, characterized in that, Including the high-strength coating as described in any one of claims 1 to 8.

Images