Protective coating for limiting rope in aviation oxygen supply mask pipeline and preparation method of protective coating

Abstract

The invention discloses a protective coating for a limiting rope in an aviation oxygen supply mask pipeline and a preparation method of the protective coating, and relates to the technical field of coatings. The protective coating prepared by the invention is prepared from modified polyacrylate, tackifying resin, a wetting dispersant, a defoaming agent, isopropanol, water, modified silicon dioxide, an emulsifier and a cationic photoinitiator. The modified polyacrylate is obtained by reacting an acylating chlorinated acrylate polymer with potassium thiocyanate, then reacting with 5-[4-(dimethylamino) phenyl]-1, 3, 4-oxadiazole-2-amine, and then reacting with epichlorohydrin; the modified silicon dioxide is obtained by grafting pretreated silicon dioxide with 4-(allyloxy)-2, 2, 6, 6-tetramethylpiperidine, reacting with methacrylic anhydride and polymerizing styrene and butadiene on the surface of the modified silicon dioxide. The protective coating prepared by the invention has good antibacterial, anti-aging and mechanical properties.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, in particular to a protective coating for a limiting rope in an aviation oxygen supply mask pipeline and a preparation method thereof. Background Art

[0002] The restraining rope in the aviation oxygen mask pipeline is a key component connecting the mask to the oxygen supply system. It plays an important role in stabilizing the position of the mask and ensuring unimpeded oxygen supply during flight. In order to improve the durability, safety and hygiene of the restraining rope, a layer of special protective coating is usually applied on its surface.

[0003] This type of protective coating is mostly made of high-performance polymer materials, which not only need to have excellent wear resistance, corrosion resistance and high temperature resistance, but also need to have mildew resistance, antibacterial and anti-aging functions to extend the service life of the restraint rope. More importantly, the protective coating can be evenly applied to the rope surface without affecting the assembly operation, and can be re-cured even after knotting, ensuring that the coating can maintain a stable protective effect at all parts of the rope. The characteristics of re-curing not only enhance the firmness of the coating, but also further improve the strength and stability of the knot.

[0004] In summary, the protective coating used for the restraining rope inside the aviation oxygen mask pipeline requires a multifunctional coating that is wear-resistant, corrosion-resistant, high-temperature-resistant, mildew-resistant, antibacterial and anti-aging, aiming to ensure that the restraining rope can maintain excellent performance in various extreme environments and provide solid protection for flight safety. Summary of the invention

[0005] The purpose of the present invention is to provide a protective coating for a limiting rope in an aviation oxygen supply mask pipeline and a preparation method thereof, so as to solve the problems existing in the prior art.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: A method for preparing a protective coating for a limiting rope in an aviation oxygen supply mask pipeline comprises the following preparation steps: (1) Polymerizing acrylic acid, methyl methacrylate and butyl acrylate to obtain polyacrylate; mixing polyacrylate and thionyl chloride to obtain polyacrylate chloride; (2) reacting the acyl chloride polyacrylate with potassium thiocyanate, and then reacting with 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine to obtain a pre-modified polyacrylate; reacting the pre-modified polyacrylate with epichlorohydrin to obtain a modified polyacrylate; (3) reacting pretreated silica, dichloromethane, and 4-(allyloxy)-2,2,6,6-tetramethylpiperidine to obtain pre-modified silica; reacting pre-modified silica and methacrylic anhydride to obtain vinyl silica; (4) Polymerizing styrene and butadiene on the surface of vinyl silica under the initiation of n-butyl lithium to obtain modified silica; (5) Weigh the following raw materials, by mass: 100 parts of modified polyacrylate, 10-15 parts of tackifying resin, 3-5 parts of wetting and dispersing agent, 3-5 parts of defoaming agent, 10-20 parts of isopropyl alcohol, 30-40 parts of water, 5-10 parts of modified silica, 5-6 parts of emulsifier, and 2-3 parts of cationic photoinitiator; mix and grind the above components, and prepare an emulsion with a particle size of 25 μm using a high-pressure homogenizer; and obtain a protective coating for the internal restraining rope of an aviation oxygen mask pipeline.

[0007] As an optimization, the preparation method of the polyacrylate chlorinated in step (1) is as follows: acrylic acid, methyl methacrylate, butyl acrylate, azobisisobutyronitrile and isopropanol are mixed in a mass ratio of 1: (0.7-0.8): (0.5-0.6): (0.01-0.02): (20-30), heated to 82-85°C, refluxed and stirred for 2-3h, and subjected to reduced pressure rotary evaporation and vacuum drying to obtain polyacrylate; polyacrylate, dichlorothionyl and N,N-dimethylformamide are mixed in a mass ratio of 1: (5-6): (0.2-0.3), heated to 65-75°C, reacted for 40-50min, and subjected to reduced pressure distillation to obtain polyacrylate chlorinated.

[0008] As an optimization, the preparation method of the modified polyacrylate in step (2) is as follows: under nitrogen protection, chlorinated polyacrylate, 10wt% potassium thiocyanate aqueous solution, N,N-dimethylformamide, and triethylamine are mixed in a mass ratio of 1:(0.5-0.6):(20-30):(0.3-0.5) for 30-40 minutes, filtered and the filtrate is retained, 0.6-0.8 times the mass of chlorinated polyacrylate 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine is added to the filtrate, reacted at 60-70°C for 3-5 hours, cooled to room temperature, and then subjected to reduced pressure rotary evaporation to obtain pre-modified polyacrylate; pre-modified polyacrylate, epichlorohydrin, and N,N-dimethylformamide are mixed in a mass ratio of 1:(0.2-0.3):(20-30), heated to 70-80°C, stirred for 6-8 hours, precipitated with pure water, filtered, washed, and dried to obtain modified polyacrylate.

[0009] As an optimization, the preparation method of the vinyl silica in step (3) is as follows: silica and ethanol are mixed, the pH value is adjusted to 4 using a 40wt% hydrochloric acid solution, mercaptopropyl trimethoxysilane is added and ultrasonically mixed for 10 minutes, the temperature is raised to 80°C and stirred for 5-7 hours, and the pretreated silica is obtained by filtering, washing, and drying; the mass ratio of silica, ethanol, and mercaptopropyl trimethoxysilane is 1:(10-20):(0.2-0.3); the pretreated silica, dichloromethane, 4-(allyloxy)-2,2,6,6-tetramethylpiperidine, dimethoxysilane are mixed and the mixture is stirred for 10 minutes. Methylphenylphosphine is mixed in a mass ratio of 1: (20-30): (0.3-0.5): (0.01-0.02), heated to 40-50 ° C and reacted for 10-12 hours, filtered, washed and dried to obtain pre-modified silica; pre-modified silica, dimethylaminopyridine, triethylamine, dichloromethane and methacrylic anhydride are mixed in a mass ratio of 1: (0.1-0.2): (2-3): (50-60): (1-2), stirred at room temperature for 10-12 hours, filtered, washed with saturated sodium carbonate solution and dried to obtain vinyl silica.

[0010] As an optimization, the preparation method of the modified silica in step (4) is as follows: styrene, vinyl silica, cyclohexane, n-butyl lithium, propylene oxide, and epichlorohydrin are weighed in a mass ratio of 2:(5-6):(35-40):0.04:(0.03-0.05):(0.1-0.2); under nitrogen protection, half of the styrene, vinyl silica, and cyclohexane are mixed and heated to 60°C, one quarter of n-butyl lithium is added for 3-5 minutes, and then the remaining n-butyl lithium is added, and the reaction is continued for 30-40 minutes, and then butadiene with a mass of 1-2 times that of styrene is added and the reaction is continued for 35-45 minutes, and then the remaining styrene is added to react for 30-40 minutes, propylene oxide is added to react for 10 minutes, and epichlorohydrin is added to react for 15 minutes, and the modified silica is obtained by filtering, washing, and drying.

[0011] As an optimization, the particle size of the silicon dioxide is 200 nm.

[0012] As an optimization, the tackifying resin in step (5) is Arakawa rosin GA-90; the wetting and dispersing agent is Disperbyk-190; the defoaming agent is BYK1758; the emulsifier is OP-10; and the cationic photoinitiator is cationic photoinitiator 250.

[0013] The present invention also provides a protective coating for limiting ropes in aviation oxygen supply mask pipelines prepared according to the method for preparing a protective coating for limiting ropes in aviation oxygen supply mask pipelines described in any one of the above items.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are: The protective coating prepared by the invention comprises modified polyacrylate, tackifying resin, wetting dispersant, defoaming agent, isopropyl alcohol, water, modified silicon dioxide, emulsifier and cationic photoinitiator; the modified polyacrylate is obtained by reacting an acyl chloride acrylic polymer with potassium thiocyanate, then reacting with 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine, and then reacting with epichlorohydrin; the modified silicon dioxide is obtained by grafting 4-(allyloxy)-2,2,6,6-tetramethylpiperidine onto pretreated silicon dioxide, then reacting with methacrylic anhydride, and polymerizing styrene and butadiene on the surface thereof.

[0015] First, the acyl chloride acrylic polymer reacts with potassium thiocyanate and then reacts with 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine to generate an acylthiourea grafted oxadiazole structure, which gives the material good antibacterial properties. Epichlorohydrin reacts with the dimethylamino group on 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine to generate a quaternary ammonium salt structure with antibacterial properties, which can further improve the antibacterial properties of the material and introduce epoxy groups. Secondly, the silicon dioxide containing vinyl groups on the surface is reacted with 4-(allyloxy)-2,2,6,6-tetramethylpiperidine to graft functional groups with antioxidant properties, and then reacted with methacrylic anhydride to graft vinyl groups, and anion polymerized with styrene and butadiene under the action of n-butyl lithium to generate styrene-butadiene-styrene block polymers with good toughness, giving the material good toughness, and epichlorohydrin is used as a capping agent to introduce epoxy functional groups; Finally, the modified polyacrylate, tackifying resin, wetting dispersant, defoaming agent, isopropyl alcohol, water, modified silica, emulsifier and cationic photoinitiator are mixed to obtain a protective coating. The protective coating prepared by the present invention is a thermoplastic protective coating, which has good adhesion to the restriction rope substrate. After the coating is applied to the restriction rope and then naturally air-dried, a stable film at room temperature is formed on the surface of the restriction rope, allowing normal assembly. After the assembly is completed, the restriction rope is knotted. At high temperature, the coating will undergo softening and re-bonding, and the epoxy groups on the side chains of the modified polyacrylate and the epoxy groups on the modified silica will undergo ring-opening polymerization under the action of light and cationic photoinitiator to generate a more complex cross-linked network, further enhancing the cross-linking at the knot, which can effectively prevent the knot from opening. DETAILED DESCRIPTION

[0016] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0017] In the following examples and comparative examples, the particle size of the silicon dioxide is 200 nm; the tackifying resin is Arakawa rosin GA-90; the wetting and dispersing agent is Disperbyk-190; the defoaming agent is BYK1758; the emulsifier is OP-10; and the cationic photoinitiator is cationic photoinitiator 250. Example 1

[0018] A method for preparing a protective coating for a limiting rope in an aviation oxygen supply mask pipeline, the method comprising the following steps: (1) Acrylic acid, methyl methacrylate, butyl acrylate, azobisisobutyronitrile and isopropanol were mixed in a mass ratio of 1:0.7:0.5:0.01:20, heated to 85°C, refluxed and stirred for 3 hours, and vacuum-evaporated and dried to obtain polyacrylate; polyacrylate, thionyl chloride and N,N-dimethylformamide were mixed in a mass ratio of 1:5:0.2, heated to 75°C, reacted for 50 minutes and vacuum-evaporated to obtain polyacrylate chloride; (2) Under nitrogen protection, polyacrylate chloride, 10wt% potassium thiocyanate aqueous solution, N,N-dimethylformamide, and triethylamine were mixed in a mass ratio of 1:0.5:20:0.3 for 40 minutes, filtered and the filtrate was retained, 0.6 times the mass of polyacrylate chloride 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine was added to the filtrate, and the mixture was reacted at 70°C for 5 hours. After cooling to room temperature, the pre-modified polyacrylate was obtained by vacuum rotary evaporation; the pre-modified polyacrylate, epichlorohydrin, and N,N-dimethylformamide were mixed in a mass ratio of 1:0.2:20, heated to 80°C and stirred for 8 hours, precipitated with pure water, filtered, washed, and dried to obtain the modified polyacrylate; (3) Mix silica and ethanol, adjust the pH to 4 with 40wt% hydrochloric acid solution, add mercaptopropyl trimethoxysilane and mix ultrasonically for 10 minutes, heat to 80°C and stir for 5 hours, filter, wash and dry to obtain pretreated silica; the mass ratio of silica, ethanol and mercaptopropyl trimethoxysilane is 1:10:0.2; mix pretreated silica, dichloromethane, 4-(allyloxy)-2,2,6,6-tetramethylpiperidine and dimethylphenylphosphine in a mass ratio of 1:20:0.3:0.01, heat to 50°C and react for 12 hours, filter, wash and dry to obtain pre-modified silica; mix pre-modified silica, dimethylaminopyridine, triethylamine, dichloromethane and methacrylic anhydride in a mass ratio of 1:0.1:2:50:1, stir at room temperature for 12 hours, filter, wash with saturated sodium carbonate solution and dry to obtain vinyl silica; (4) Styrene, vinyl silica, cyclohexane, n-butyl lithium, propylene oxide, and epichlorohydrin were weighed in a mass ratio of 2:5:35:0.04:0.03:0.1; under nitrogen protection, half of the styrene, vinyl silica, and cyclohexane were mixed and heated to 60°C, one quarter of n-butyl lithium was added for 5 minutes, and then the remaining n-butyl lithium was added and reacted for 40 minutes, butadiene with a mass of 1 times that of styrene was added and continued to react for 45 minutes, and then the remaining styrene was added and reacted for 40 minutes, propylene oxide was added and reacted for 10 minutes, and epichlorohydrin was added and reacted for 15 minutes, and the modified silica was obtained by filtering, washing, and drying; (5) Weigh the following raw materials, by mass: 100 parts of modified polyacrylate, 10 parts of tackifying resin, 3 parts of wetting and dispersing agent, 3 parts of defoaming agent, 10 parts of isopropyl alcohol, 30 parts of water, 5 parts of modified silica, 5 parts of emulsifier, and 2 parts of cationic photoinitiator; mix and grind the above components, and prepare an emulsion with a particle size of 25 μm using a high-pressure homogenizer; and obtain a protective coating for the internal restraining rope of an aviation oxygen mask pipeline. Example 2

[0019] A method for preparing a protective coating for a limiting rope in an aviation oxygen supply mask pipeline, the method comprising the following steps: (1) Acrylic acid, methyl methacrylate, butyl acrylate, azobisisobutyronitrile and isopropanol were mixed in a mass ratio of 1:0.75:0.55:0.01:25, heated to 83°C, refluxed and stirred for 2.5 hours, and vacuum-evaporated and dried to obtain polyacrylate; polyacrylate, thionyl chloride and N,N-dimethylformamide were mixed in a mass ratio of 1:5.5:0.25, heated to 70°C, reacted for 45 minutes and vacuum-evaporated to obtain polyacrylate chloride; (2) Under nitrogen protection, polyacrylate chloride, 10wt% potassium thiocyanate aqueous solution, N,N-dimethylformamide, and triethylamine were mixed in a mass ratio of 1:0.55:25:0.4 for 35 minutes, filtered and the filtrate was retained, 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine (0.7 times the mass of polyacrylate chloride) was added to the filtrate, reacted at 65°C for 4 hours, cooled to room temperature, and then vacuum evaporated to obtain pre-modified polyacrylate; pre-modified polyacrylate, epichlorohydrin, and N,N-dimethylformamide were mixed in a mass ratio of 1:0.25:25, heated to 75°C and stirred for 7 hours, precipitated with pure water, filtered, washed, and dried to obtain modified polyacrylate; (3) Silica and ethanol were mixed, and the pH was adjusted to 4 with a 40wt% hydrochloric acid solution. After adding mercaptopropyl trimethoxysilane and ultrasonically mixing for 10 minutes, the temperature was raised to 80°C and stirred for 6 hours, and then filtered, washed, and dried to obtain pretreated silica; the mass ratio of silica, ethanol, and mercaptopropyl trimethoxysilane was 1:15:0.25; pretreated silica, dichloromethane, 4-(allyloxy)-2,2,6,6-tetramethylpiperidine, and dimethylphenylphosphine were mixed in a mass ratio of 1:25:0.4:0.015, heated to 45°C and reacted for 11 hours, filtered, washed, and dried to obtain pre-modified silica; pre-modified silica, dimethylaminopyridine, triethylamine, dichloromethane, and methacrylic anhydride were mixed in a mass ratio of 1:0.15:2.5:55:1.5, stirred at room temperature for 11 hours, filtered, washed with a saturated sodium carbonate solution, and dried to obtain vinyl silica; (4) Styrene, vinyl silica, cyclohexane, n-butyl lithium, propylene oxide, and epichlorohydrin were weighed in a mass ratio of 2:5.5:37:0.04:0.04:0.15; under nitrogen protection, half of the styrene, vinyl silica, and cyclohexane were mixed and heated to 60°C, one quarter of n-butyl lithium was added for 4 minutes, and then the remaining n-butyl lithium was added and reacted for 35 minutes, butadiene 1.5 times the mass of styrene was added and continued to react for 40 minutes, and then the remaining styrene was added and reacted for 35 minutes, propylene oxide was added and reacted for 10 minutes, and epichlorohydrin was added and reacted for 15 minutes, and the modified silica was obtained by filtering, washing, and drying; (5) Weigh the following raw materials, by mass: 100 parts of modified polyacrylate, 13 parts of tackifying resin, 4 parts of wetting and dispersing agent, 4 parts of defoaming agent, 15 parts of isopropyl alcohol, 35 parts of water, 7 parts of modified silica, 5 parts of emulsifier, and 2 parts of cationic photoinitiator; mix and grind the above components, and prepare an emulsion with a particle size of 25 μm using a high-pressure homogenizer; and obtain a protective coating for the restraining rope in the pipeline of an aviation oxygen mask. Example 3

[0020] A method for preparing a protective coating for a limiting rope in an aviation oxygen supply mask pipeline, the method comprising the following preparation steps: (1) Acrylic acid, methyl methacrylate, butyl acrylate, azobisisobutyronitrile and isopropanol were mixed in a mass ratio of 1:0.8:0.6:0.02:30, heated to 82°C, refluxed and stirred for 2 hours, and vacuum-evaporated and dried to obtain polyacrylate; polyacrylate, thionyl chloride and N,N-dimethylformamide were mixed in a mass ratio of 1:6:0.3, heated to 65°C, reacted for 40 minutes and vacuum-evaporated to obtain polyacrylate chloride; (2) Under nitrogen protection, polyacrylate chloride, 10wt% potassium thiocyanate aqueous solution, N,N-dimethylformamide, and triethylamine were mixed at a mass ratio of 1:0.6:30:0.5 for 30 minutes, filtered and the filtrate was retained, 0.8 times the mass of polyacrylate chloride 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine was added to the filtrate, and the mixture was reacted at 60°C for 3 hours. After cooling to room temperature, the pre-modified polyacrylate was obtained by vacuum rotary evaporation; the pre-modified polyacrylate, epichlorohydrin, and N,N-dimethylformamide were mixed at a mass ratio of 1:0.3:30, heated to 70°C and stirred for 6 hours, precipitated with pure water, filtered, washed, and dried to obtain the modified polyacrylate; (3) Mix silica and ethanol, adjust the pH to 4 with 40wt% hydrochloric acid solution, add mercaptopropyl trimethoxysilane and mix ultrasonically for 10 minutes, heat to 80°C and stir for 5 hours, filter, wash and dry to obtain pretreated silica; the mass ratio of silica, ethanol and mercaptopropyl trimethoxysilane is 1:20:0.3; mix pretreated silica, dichloromethane, 4-(allyloxy)-2,2,6,6-tetramethylpiperidine and dimethylphenylphosphine in a mass ratio of 1:30:0.5:0.02, heat to 40°C and react for 10 hours, filter, wash and dry to obtain pre-modified silica; mix pre-modified silica, dimethylaminopyridine, triethylamine, dichloromethane and methacrylic anhydride in a mass ratio of 1:0.2:3:60:2, stir at room temperature for 10 hours, filter, wash with saturated sodium carbonate solution and dry to obtain vinyl silica; (4) Styrene, vinyl silica, cyclohexane, n-butyl lithium, propylene oxide, and epichlorohydrin were weighed in a mass ratio of 2:6:40:0.04:0.05:0.2; under nitrogen protection, half of the styrene, vinyl silica, and cyclohexane were mixed and heated to 60°C, one quarter of n-butyl lithium was added for 3 minutes, and then the remaining n-butyl lithium was added and reacted for 30 minutes, butadiene twice the mass of styrene was added and continued to react for 35 minutes, and then the remaining styrene was added and reacted for 30 minutes, propylene oxide was added and reacted for 10 minutes, and epichlorohydrin was added and reacted for 15 minutes, and the modified silica was obtained by filtering, washing, and drying; (5) Weigh the following raw materials, by mass: 100 parts of modified polyacrylate, 15 parts of tackifying resin, 5 parts of wetting and dispersing agent, 5 parts of defoaming agent, 20 parts of isopropyl alcohol, 40 parts of water, 10 parts of modified silica, 6 parts of emulsifier, and 3 parts of cationic photoinitiator; mix and grind the above components, and prepare an emulsion with a particle size of 25 μm using a high-pressure homogenizer; and obtain a protective coating for the internal restraining rope of an aviation oxygen mask pipeline.

[0021] Comparative Example 1: The preparation method of the protective coating for the internal restriction rope of the aviation oxygen mask pipeline of Comparative Example 1 is different from that of Example 2 in that the polyacrylate is not modified; specifically, step (2) is not included, and step (1) is modified as follows: acrylic acid, methyl methacrylate, butyl acrylate, azobisisobutyronitrile, and isopropanol are mixed in a mass ratio of 1:0.75:0.55:0.01:25, heated to 83°C, refluxed and stirred for 2.5 hours, and subjected to reduced pressure rotary evaporation and vacuum drying to obtain modified polyacrylate. The remaining steps are the same as those of Example 2.

[0022] Comparative Example 2: The preparation method of the protective coating for the inner limit rope of the aviation oxygen mask pipeline of Comparative Example 2 is different from that of Example 2 in that the silicon dioxide is not modified, specifically, steps (3) to (4) are not included, and step (5) is modified as follows: weigh the following raw materials, by mass: 100 parts of modified polyacrylate, 13 parts of tackifying resin, 4 parts of wetting dispersant, 4 parts of defoaming agent, 15 parts of isopropanol, 35 parts of water, 7 parts of silicon dioxide, 5 parts of emulsifier, and 2 parts of cationic photoinitiator; mix and grind the above components, and prepare an emulsion with a particle size of 25 μm using a high-pressure homogenizer; and obtain the protective coating for the inner limit rope of the aviation oxygen mask pipeline. The remaining steps are the same as those of Example 2.

[0023] Comparative Example 3: The preparation method of the protective coating for the inner limit rope of the oxygen mask pipeline of the aviation supply in comparative example 3 is different from that of example 2 in that it does not contain a cationic photoinitiator. Specifically, step (5) is modified as follows: weigh the following raw materials, by mass: 100 parts of modified polyacrylate, 13 parts of tackifying resin, 4 parts of wetting dispersant, 4 parts of defoaming agent, 15 parts of isopropanol, 35 parts of water, 7 parts of modified silicon dioxide, and 5 parts of emulsifier; mix and grind the above components, and prepare an emulsion with a particle size of 25 μm using a high-pressure homogenizer; and obtain the protective coating for the inner limit rope of the oxygen mask pipeline of the aviation supply. The remaining steps are the same as those of example 2.

[0024] Test Example 1: Antibacterial performance test: Test method: Pour the coating into a polytetrafluoroethylene mold and place it in a 40°C forced air drying oven to cure for 12 hours to obtain the coating. The antibacterial rate of the coating was tested according to standard QB / T 2591-2003, and the results are shown in Table 1.

[0025] Table 1

[0026] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 1, it can be found that the protective coating for the restriction rope in the pipeline of the aviation oxygen supply mask prepared by the present invention has good antibacterial properties.

[0027] Comparative Example 1 does not perform antibacterial modification on polyacrylate, and the antibacterial properties of Examples 1 to 3 are better than those of Comparative Example 1, indicating that the acyl chloride acrylic polymer reacts with potassium thiocyanate and then reacts with 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine to generate an acylthiourea grafted oxadiazole structure, which gives the material good antibacterial properties. Epichlorohydrin reacts with the dimethylamino group on 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine to generate a quaternary ammonium salt structure with antibacterial properties, which can further improve the antibacterial properties of the material.

[0028] Test Example 2: Mechanical properties test: Test method: Pour the coating into a polytetrafluoroethylene mold and test it at an intensity of 60mW / cm 2 The samples were prepared by curing under the conditions of light and 40°C; referring to the standard of GB / T 6739-2006; the pencil hardness of the samples was tested by a pendulum damping tester. The results are shown in Table 2.

[0029] Anti-aging performance test: Test method: Place the sample in a thermal oxygen aging box for aging for 480 hours at a temperature of 60°C and a relative humidity of 55%. Test the aged film according to the mechanical properties test method. The results are shown in Table 2.

[0030] Table 2

[0031] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 2, it can be found that the protective coating for the limiting rope in the pipeline of the aviation oxygen supply mask prepared by the present invention has good mechanical properties and anti-aging properties.

[0032] The mechanical properties of Examples 1 to 3 are better than those of Comparative Examples 1 to 3, and the anti-aging properties of Examples 1 to 3 are better than those of Comparative Example 2, indicating that after the acyl chloride acrylic polymer reacts with potassium thiocyanate and then reacts with 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine, the dimethylamino groups on epichlorohydrin and 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine can be introduced into epoxy groups; the surface-containing vinyl group-containing silica and 4-(allyloxy)-2, It reacts with 2,6,6-tetramethylpiperidine, and then reacts with methacrylic anhydride to graft vinyl. Under the action of n-butyl lithium, it undergoes anionic polymerization with styrene and butadiene to generate styrene-butadiene-styrene block polymers with good toughness, giving the material good toughness. Epichlorohydrin is used as a capping agent to introduce epoxy functional groups. The epoxy groups on the side chains of modified polyacrylates and the epoxy groups on modified silica will undergo ring-opening polymerization under the action of light and cationic photoinitiators to generate a more complex cross-linked network, further enhancing the cross-linking.

[0033] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for preparing a protective coating for a limiting rope in an aviation oxygen mask pipeline, characterized in that: The method comprises the following preparation steps: (1) Polymerizing acrylic acid, methyl methacrylate and butyl acrylate to obtain polyacrylate; mixing polyacrylate and thionyl chloride to obtain polyacrylate chloride; (2) reacting the acyl chloride polyacrylate with potassium thiocyanate, and then reacting with 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine to obtain a pre-modified polyacrylate; reacting the pre-modified polyacrylate with epichlorohydrin to obtain a modified polyacrylate; (3) reacting pretreated silica, dichloromethane, and 4-(allyloxy)-2,2,6,6-tetramethylpiperidine to obtain pre-modified silica; reacting pre-modified silica and methacrylic anhydride to obtain vinyl silica; (4) Polymerizing styrene and butadiene on the surface of vinyl silica under the initiation of n-butyl lithium to obtain modified silica; (5) Weigh the following raw materials, by mass: 100 parts of modified polyacrylate, 10-15 parts of tackifying resin, 3-5 parts of wetting and dispersing agent, 3-5 parts of defoaming agent, 10-20 parts of isopropyl alcohol, 30-40 parts of water, 5-10 parts of modified silica, 5-6 parts of emulsifier, and 2-3 parts of cationic photoinitiator; mix and grind the above components, and prepare an emulsion with a particle size of 25 μm using a high-pressure homogenizer; and obtain a protective coating for the internal restraining rope of an aviation oxygen mask pipeline.

2. The method for preparing a protective coating for a limiting rope in an aviation oxygen supply mask pipeline according to claim 1, characterized in that: The preparation method of the polyacrylate chlorinated in step (1) is as follows: acrylic acid, methyl methacrylate, butyl acrylate, azobisisobutyronitrile and isopropanol are mixed in a mass ratio of 1: (0.7-0.8): (0.5-0.6): (0.01-0.02): (20-30), heated to 82-85°C, refluxed and stirred for 2-3h, and subjected to reduced pressure rotary evaporation and vacuum drying to obtain polyacrylate; polyacrylate, dithionyl chloride and N,N-dimethylformamide are mixed in a mass ratio of 1: (5-6): (0.2-0.3), heated to 65-75°C, reacted for 40-50min, and subjected to reduced pressure distillation to obtain polyacrylate chlorinated.

3. The method for preparing a protective coating for a limiting rope in an aviation oxygen supply mask pipeline according to claim 1, characterized in that: The preparation method of the modified polyacrylate in step (2) is as follows: under nitrogen protection, chlorinated polyacrylate, 10wt% potassium thiocyanate aqueous solution, N,N-dimethylformamide, and triethylamine are mixed in a mass ratio of 1:(0.5-0.6):(20-30):(0.3-0.5) for 30-40 minutes, filtered and the filtrate is retained, 0.6-0.8 times the mass of chlorinated polyacrylate 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazole-2-amine is added to the filtrate, reacted at 60-70°C for 3-5 hours, cooled to room temperature, and then subjected to reduced pressure rotary evaporation to obtain pre-modified polyacrylate; pre-modified polyacrylate, epichlorohydrin, and N,N-dimethylformamide are mixed in a mass ratio of 1:(0.2-0.3):(20-30), heated to 70-80°C, stirred for 6-8 hours, precipitated with pure water, filtered, washed, and dried to obtain modified polyacrylate.

4. The method for preparing a protective coating for a limiting rope in an aviation oxygen supply mask pipeline according to claim 1, characterized in that: The preparation method of the vinyl silica in step (3) is as follows: silica and ethanol are mixed, the pH value is adjusted to 4 using a 40wt% hydrochloric acid solution, mercaptopropyl trimethoxysilane is added and ultrasonically mixed for 10 minutes, the temperature is raised to 80°C and stirred for 5-7 hours, and the pretreated silica is obtained by filtering, washing, and drying; the mass ratio of silica, ethanol, and mercaptopropyl trimethoxysilane is 1:(10-20):(0.2-0.3); the pretreated silica, dichloromethane, 4-(allyloxy)-2,2,6,6-tetramethylpiperidine, and dimethylbenzene are mixed. The base phosphine is mixed in a mass ratio of 1: (20-30): (0.3-0.5): (0.01-0.02), the temperature is raised to 40-50 ° C and the reaction is carried out for 10-12 hours, and the pre-modified silica is obtained by filtering, washing and drying; the pre-modified silica, dimethylaminopyridine, triethylamine, dichloromethane and methacrylic anhydride are mixed in a mass ratio of 1: (0.1-0.2): (2-3): (50-60): (1-2), stirred at room temperature for 10-12 hours, filtered, washed with saturated sodium carbonate solution and dried to obtain vinyl silica.

5. The method for preparing a protective coating for a limiting rope in an aviation oxygen supply mask pipeline according to claim 1, characterized in that: The preparation method of the modified silica in step (4) is as follows: styrene, vinyl silica, cyclohexane, n-butyl lithium, propylene oxide, and epichlorohydrin are weighed in a mass ratio of 2:(5-6):(35-40):0.04:(0.03-0.05):(0.1-0.2); under nitrogen protection, half of the styrene, vinyl silica, and cyclohexane are mixed and heated to 60° C., one quarter of n-butyl lithium is added for 3-5 minutes, and then the remaining n-butyl lithium is added, and the reaction is continued for 30-40 minutes, and then butadiene with a mass of 1-2 times that of styrene is added and the reaction is continued for 35-45 minutes, and then the remaining styrene is added for reaction for 30-40 minutes, propylene oxide is added for reaction for 10 minutes, and epichlorohydrin is added for reaction for 15 minutes, and the modified silica is obtained by filtering, washing, and drying.

6. The method for preparing a protective coating for a limiting rope in an aviation oxygen supply mask pipeline according to claim 4, characterized in that: The particle size of the silicon dioxide is 200 nm.

7. The method for preparing a protective coating for a limiting rope in an aviation oxygen supply mask pipeline according to claim 1, characterized in that: In step (5), the tackifying resin is Arakawa rosin GA-90; the wetting and dispersing agent is Disperbyk-190; the defoaming agent is BYK1758; the emulsifier is OP-10; and the cationic photoinitiator is cationic photoinitiator 250.

8. A protective coating for limiting ropes in aviation oxygen supply mask pipelines prepared according to the method for preparing a protective coating for limiting ropes in aviation oxygen supply mask pipelines according to any one of claims 1 to 7.

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