A protective coating for the restraining cord inside the air supply mask pipeline of an aircraft and its preparation method

Abstract

The present invention discloses a protective coating for a restraint cord inside an aviation oxygen supply mask pipeline and a preparation method thereof, which relates to the technical field of coatings. The protective coating prepared by the present invention comprises a modified polyacrylate, a tackifying resin, a wetting and dispersing agent, an antifoaming agent, isopropanol, water, modified silica, an emulsifier, and a cationic photoinitiator; the modified polyacrylate is obtained by reacting an acrylate polymer subjected to acyl chlorination with potassium thiocyanate, then reacting with 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazol-2-amine, and then reacting with epichlorohydrin; the modified silica is obtained by grafting 4-(allyloxy)-2,2,6,6-tetramethylpiperidine onto pretreated silica, then reacting with methacrylic anhydride, and polymerizing styrene and butadiene on its surface. The protective coating prepared by the present invention has good antibacterial, anti-aging, and mechanical properties.

Description

Technical Field

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

[0002] The restraint rope inside the aviation oxygen supply mask pipeline, as a key component connecting the mask and the oxygen supply system, plays an important role in stabilizing the position of the mask and ensuring unobstructed oxygen supply during flight. To improve the durability, safety, and hygiene of the restraint rope, a special protective coating is usually applied to its surface.

[0003] Such protective coatings are mostly high-performance polymer materials, which not only need to have excellent wear resistance, corrosion resistance, and high-temperature resistance, but also need to have anti-mold, antibacterial, and anti-aging functions to extend the service life of the restraint rope.

[0004] More importantly, on the premise of not affecting the assembly operation, the protective coating can be evenly coated on the surface of the rope, and can be secondarily cured even after knotting, ensuring that the coating can maintain a stable protective effect on all parts of the rope. The characteristic of secondary curing not only enhances the firmness of the coating, but also further improves the strength and stability of the knotted part.

[0005] In summary, the protective coating used for the restraint rope inside the aviation oxygen supply mask pipeline requires a multifunctional coating that combines wear resistance, corrosion resistance, high-temperature resistance, anti-mold, antibacterial, and anti-aging properties, aiming to ensure that the restraint rope can maintain excellent performance in various extreme environments and provide a solid guarantee for flight safety. Summary of the Invention

[0006] The purpose of the present invention is to provide a protective coating for the restraint rope inside an aviation oxygen supply mask pipeline and a preparation method thereof to solve the problems existing in the prior art.

[0007] To solve the above technical problems, the present invention provides the following technical solutions:

[0008] A preparation method of a protective coating for the restraint rope inside an aviation oxygen supply mask pipeline, comprising the following preparation steps:

[0009] (1) Polymerize acrylic acid, methyl methacrylate, and butyl acrylate to obtain polyacrylate; mix polyacrylate and thionyl chloride to obtain acyl chloride polyacrylate;

[0010] (2) React acyl chloride polyacrylate with potassium thiocyanate, and then react with 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazol-2-amine to obtain pre-modified polyacrylate; react pre-modified polyacrylate with epichlorohydrin to obtain modified polyacrylate;

[0011] (3) React the pretreated silica, dichloromethane, and 4-(allyloxy)-2,2,6,6-tetramethylpiperidine to obtain pre-modified silica; react the pre-modified silica and methacrylic anhydride to obtain vinyl silica;

[0012] (4) Polymerize styrene and butadiene on the surface of vinyl silica under the initiation of n-butyllithium to obtain modified silica;

[0013] (5) Weigh the following raw materials, by mass parts: 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 isopropanol, 30 - 40 parts of water, 5 - 10 parts of modified silica, 5 - 6 parts of emulsifier, 2 - 3 parts of cationic photoinitiator; Mix and grind the above components, and use a high-pressure homogenizer to prepare an emulsion with a particle size of 25 μm; Obtain the protective coating for the restraint cord inside the aviation oxygen supply mask pipeline.

[0014] As an optimization, the preparation method of the acryloyl chloride polyacrylate in step (1) is: Mix acrylic acid, methyl methacrylate, butyl acrylate, azobisisobutyronitrile, and isopropanol in a mass ratio of 1:(0.7 - 0.8):(0.5 - 0.6):(0.01 - 0.02):(20 - 30), heat up to 82 - 85 °C and reflux and stir for 2 - 3 h, obtain polyacrylate through rotary evaporation under reduced pressure and vacuum drying; Mix the polyacrylate, thionyl chloride, and N,N-dimethylformamide in a mass ratio of 1:(5 - 6):(0.2 - 0.3), heat up to 65 - 75 °C and react for 40 - 50 min, and obtain acryloyl chloride polyacrylate through distillation under reduced pressure.

[0015] As an optimization, the preparation method of the modified polyacrylate in step (2) is: Under nitrogen protection, mix the acryloyl chloride polyacrylate, 10 wt% potassium thiocyanate aqueous solution, N,N-dimethylformamide, and triethylamine in a mass ratio of 1:(0.5 - 0.6):(20 - 30):(0.3 - 0.5) for 30 - 40 min, then filter and retain the filtrate. Add 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazol-2-amine which is 0.6 - 0.8 times the mass of the acryloyl chloride polyacrylate to the filtrate, react at 60 - 70 °C for 3 - 5 h, cool to room temperature, and obtain pre-modified polyacrylate through rotary evaporation under reduced pressure; Mix the pre-modified polyacrylate, epichlorohydrin, and N,N-dimethylformamide in a mass ratio of 1:(0.2 - 0.3):(20 - 30), heat up to 70 - 80 °C and stir for 6 - 8 h, and obtain modified polyacrylate through precipitation with pure water, filtration, washing, and drying.

[0016] As an optimization, the preparation method of vinyl silica in step (3) is as follows: Mix silica and ethanol, adjust the pH to 4 with 40wt% hydrochloric acid solution, add mercaptopropyltrimethoxysilane and ultrasonically mix for 10 min, then heat to 80 °C and stir for 5 - 7 h, filter, wash and dry to obtain pretreated silica; the mass ratio of silica, ethanol, and mercaptopropyltrimethoxysilane is 1:(10 - 20):(0.2 - 0.3); Mix the pretreated silica, dichloromethane, 4-(allyloxy)-2,2,6,6-tetramethylpiperidine, and dimethylphenylphosphine according to the mass ratio 1:(20 - 30):(0.3 - 0.5):(0.01 - 0.02), heat to 40 - 50 °C and react for 10 - 12 h, filter, wash and dry to obtain pre-modified silica; Mix the pre-modified silica, dimethylaminopyridine, triethylamine, dichloromethane, and methacrylic anhydride according to the mass ratio 1:(0.1 - 0.2):(2 - 3):(50 - 60):(1 - 2), stir at room temperature for 10 - 12 h, filter, wash with saturated sodium carbonate solution, and dry to obtain vinyl silica.

[0017] As an optimization, the preparation method of modified silica in step (4) is as follows: Weigh styrene, vinyl silica, cyclohexane, n-butyllithium, propylene oxide, and epichlorohydrin according to the mass ratio 2:(5 - 6):(35 - 40):0.04:(0.03 - 0.05):(0.1 - 0.2); Under nitrogen protection, mix half of the styrene, vinyl silica, and cyclohexane and heat to 60 °C, add one-fourth of n-butyllithium for 3 - 5 min, then add the remaining n-butyllithium, react for 30 - 40 min, add 1 - 2 times the mass of butadiene based on the mass of styrene and continue to react for 35 - 45 min, then add the remaining styrene and react for 30 - 40 min, add propylene oxide and react for 10 min, add epichlorohydrin and react for 15 min, filter, wash and dry to obtain modified silica.

[0018] As an optimization, the particle size of the silica is 200 nm.

[0019] As an optimization, the tackifying resin in step (5) is Arakawa rosin resin GA-90; the wetting and dispersing agent is Disperbyk-190; the defoaming agent is BYK1758; the emulsifier is OP-10; the cationic photoinitiator is cationic photoinitiator 250.

[0020] The present invention also provides an anti-corrosion coating for the restraint rope inside the aviation oxygen supply mask pipeline prepared by the preparation method of the anti-corrosion coating for the restraint rope inside the aviation oxygen supply mask pipeline according to any one of the above.

[0021] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0022] The protective coating prepared by the present invention comprises a modified polyacrylate, a tackifying resin, a wetting and dispersing agent, an antifoaming agent, isopropanol, water, modified silica, an emulsifier, and a cationic photoinitiator; the modified polyacrylate is obtained by reacting an acrylate polymer with acyl chloride and potassium thiocyanate, then reacting with 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazol-2-amine, and then reacting with epichlorohydrin; the modified silica is obtained by grafting 4-(allyloxy)-2,2,6,6-tetramethylpiperidine onto pretreated silica, then reacting with methacrylic anhydride, and polymerizing styrene and butadiene on its surface.

[0023] First, after the acrylate polymer with acyl chloride reacts with potassium thiocyanate and then reacts with 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazol-2-amine, an acylthiourea-grafted oxadiazole structure is formed, endowing the material with good antibacterial properties. Epichlorohydrin reacts with the dimethylamino group on 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazol-2-amine to form a quaternary ammonium salt structure with antibacterial properties, which can further improve the antibacterial properties of the material and introduce an epoxy group.

[0024] Second, silica with vinyl groups on its surface reacts with 4-(allyloxy)-2,2,6,6-tetramethylpiperidine to graft functional groups with antioxidant properties, then reacts with methacrylic anhydride to graft vinyl groups. Under the action of n-butyllithium, anionic polymerization is carried out with styrene and butadiene to generate a styrene-butadiene-styrene block polymer with good toughness, endowing the material with good toughness, and using epichlorohydrin as a capping agent to introduce epoxy functional groups.

[0025] Finally, the modified polyacrylate, tackifying resin, wetting and dispersing agent, antifoaming agent, isopropanol, water, modified silica, emulsifier, and cationic photoinitiator are mixed to obtain the protective coating. The protective coating prepared by the present invention is a thermoplastic protective coating, which has good adhesion to the restraint rope substrate. After the coating is applied to the restraint rope and then air-dried naturally, a film that is stable at room temperature is formed on the surface of the restraint rope, allowing normal assembly. After the assembly is completed, the restraint rope is knotted. At high temperatures, the coating will soften and re-bond, 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 the cationic photoinitiator to form a more complex crosslinked network, further enhancing the crosslinking at the knot and effectively preventing the knot from opening. Detailed implementation mode

[0026] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0027] In the following examples and comparative examples, the particle size of the silica is 200 nm; the tackifying resin is Arakawa rosin ester GA-90; the wetting and dispersing agent is Disperbyk-190; the defoaming agent is BYK1758; the emulsifier is OP-10; the cationic photoinitiator is cationic photoinitiator 250. Example 1

[0028] A preparation method of a protective coating for the restraint rope inside the aviation oxygen supply mask pipeline, the preparation method comprising the following preparation steps:

[0029] (1) Mix acrylic acid, methyl methacrylate, butyl acrylate, azobisisobutyronitrile, and isopropanol in a mass ratio of 1:0.7:0.5:0.01:20, heat up to 85 °C and reflux and stir for 3 h, and obtain polyacrylate through reduced-pressure rotary evaporation and vacuum drying; Mix polyacrylate, thionyl chloride, and N,N-dimethylformamide in a mass ratio of 1:5:0.2, heat up to 75 °C and react for 50 min, and obtain acryloyl chloride polyacrylate through reduced-pressure distillation;

[0030] (2) Under nitrogen protection, mix acryloyl chloride polyacrylate, 10 wt% potassium thiocyanate aqueous solution, N,N-dimethylformamide, and triethylamine in a mass ratio of 1:0.5:20:0.3 for 40 min, then filter and retain the filtrate. Add 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazol-2-amine which is 0.6 times the mass of acryloyl chloride polyacrylate to the filtrate, react at 70 °C for 5 h, cool to room temperature, and obtain pre-modified polyacrylate through reduced-pressure rotary evaporation; Mix pre-modified polyacrylate, epichlorohydrin, and N,N-dimethylformamide in a mass ratio of 1:0.2:20, heat up to 80 °C and stir for 8 h, and obtain modified polyacrylate through precipitation with pure water, filtration, washing, and drying;

[0031] (3) Mix silicon dioxide and ethanol, adjust the pH to 4 using a 40 wt% hydrochloric acid solution, add 3-mercaptopropyltrimethoxysilane, and ultrasonically mix for 10 min. Then, heat to 80 °C and stir for 5 h. Filter, wash, and dry to obtain pretreated silicon dioxide. The mass ratio of silicon dioxide, ethanol, and 3-mercaptopropyltrimethoxysilane is 1:10:0.2. Mix the pretreated silicon dioxide, 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 h. Filter, wash, and dry to obtain pre-modified silicon dioxide. Mix the pre-modified silicon dioxide, dimethylaminopyridine, triethylamine, dichloromethane, and methacrylic anhydride in a mass ratio of 1:0.1:2:50:1. Stir at room temperature for 12 h. Filter, wash with saturated sodium carbonate solution, and dry to obtain vinyl silicon dioxide.

[0032] (4) Weigh styrene, vinyl silicon dioxide, cyclohexane, n-butyllithium, propylene oxide, and epichlorohydrin according to a mass ratio of 2:5:35:0.04:0.03:0.1. Under nitrogen protection, mix half of the styrene, vinyl silicon dioxide, and cyclohexane and heat to 60 °C. Add one-fourth of the n-butyllithium. After 5 min, add the remaining n-butyllithium and react for 40 min. Add butadiene in an amount equal to the mass of styrene and continue to react for 45 min. Then add the remaining styrene and react for 40 min. Add propylene oxide and react for 10 min. Add epichlorohydrin and react for 15 min. Filter, wash, and dry to obtain modified silicon dioxide.

[0033] (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 isopropanol, 30 parts of water, 5 parts of modified silicon dioxide, 5 parts of emulsifier, and 2 parts of cationic photoinitiator. Mix the above components evenly and grind them, and use a high-pressure homogenizer to prepare an emulsion with a particle size of 25 μm. Obtain the protective coating for the restraint cord inside the aviation oxygen supply mask pipeline. Example 2

[0034] A preparation method of a protective coating for the restraint cord inside the aviation oxygen supply mask pipeline, the preparation method includes the following preparation steps:

[0035] (1) Mix acrylic acid, methyl methacrylate, butyl acrylate, azobisisobutyronitrile, and isopropanol according to a mass ratio of 1:0.75:0.55:0.01:25. Heat to 83 °C and reflux and stir for 2.5 h. After rotary evaporation under reduced pressure and vacuum drying, obtain polyacrylate. Mix the polyacrylate, thionyl dichloride, and N,N-dimethylformamide according to a mass ratio of 1:5.5:0.25. Heat to 70 °C and react for 45 min, then perform distillation under reduced pressure to obtain acryloyl chloride polyacrylate.

[0036] (2) Under nitrogen protection, acryloylated polyacrylate, 10 wt% aqueous potassium thiocyanate solution, N,N-dimethylformamide, and triethylamine were mixed in a mass ratio of 1:0.55:25:0.4 for 35 min, then filtered and the filtrate was retained. 5-[4-(Dimethylamino)phenyl]-1,3,4-oxadiazol-2-amine, which was 0.7 times the mass of the acryloylated polyacrylate, was added to the filtrate, and the reaction was carried out at 65 °C for 4 h. After cooling to room temperature, the pre-modified polyacrylate was obtained by rotary evaporation under reduced pressure. The 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 h, and then precipitated with pure water, filtered, washed, and dried to obtain the modified polyacrylate;

[0037] (3) Silicon dioxide and ethanol were mixed, and the pH was adjusted to 4 using a 40 wt% hydrochloric acid solution. 3-Mercaptopropyltrimethoxysilane was added and ultrasonically mixed for 10 min, then heated to 80 °C and stirred for 6 h, and then filtered, washed, and dried to obtain the pretreated silicon dioxide. The mass ratio of silicon dioxide, ethanol, and 3-mercaptopropyltrimethoxysilane was 1:15:0.25. The pretreated silicon dioxide, 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 h, and then filtered, washed, and dried to obtain the pre-modified silicon dioxide. The pre-modified silicon dioxide, 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 h, and then filtered, washed with saturated sodium carbonate solution, and dried to obtain vinyl silicon dioxide;

[0038] (4) Styrene, vinyl silicon dioxide, cyclohexane, n-butyllithium, 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 silicon dioxide, and cyclohexane were mixed and heated to 60 °C. One-fourth of the n-butyllithium was added, and after 4 min, the remaining n-butyllithium was added. The reaction was carried out for 35 min, 1.5 times the mass of butadiene based on the mass of styrene was added and the reaction continued for 40 min, then the remaining styrene was added and the reaction was carried out for 35 min, propylene oxide was added and the reaction was carried out for 10 min, and epichlorohydrin was added and the reaction was carried out for 15 min. After filtration, washing, and drying, the modified silicon dioxide was obtained;

[0039] (5) The following raw materials were weighed: 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 isopropanol, 35 parts of water, 7 parts of modified silicon dioxide, 5 parts of emulsifier, and 2 parts of cationic photoinitiator by mass. The above components were mixed and ground, and a latex with a particle size of 25 μm was prepared using a high-pressure homogenizer; a protective coating for the restraint cord inside the aviation oxygen supply mask pipeline was obtained. Example 3

[0040] Preparation method of protective coating for restraint rope inside aviation oxygen supply mask pipeline, the preparation method of the protective coating for the restraint rope inside the aviation oxygen supply mask pipeline includes the following preparation steps:

[0041] (1) Mix acrylic acid, methyl methacrylate, butyl acrylate, azobisisobutyronitrile, and isopropanol according to a mass ratio of 1:0.8:0.6:0.02:30, heat up to 82 °C and reflux and stir for 2 h, and obtain polyacrylate through reduced pressure rotary evaporation and vacuum drying; Mix polyacrylate, thionyl chloride, and N,N-dimethylformamide according to a mass ratio of 1:6:0.3, heat up to 65 °C and react for 40 min, and then carry out reduced pressure distillation to obtain acryloyl chloride polyacrylate;

[0042] (2) Under nitrogen protection, mix acryloyl chloride polyacrylate, 10 wt% potassium thiocyanate aqueous solution, N,N-dimethylformamide, and triethylamine according to a mass ratio of 1:0.6:30:0.5, stir for 30 min, filter and retain the filtrate, add 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazol-2-amine which is 0.8 times the mass of acryloyl chloride polyacrylate to the filtrate, react at 60 °C for 3 h, cool to room temperature, and obtain pre-modified polyacrylate through reduced pressure rotary evaporation; Mix pre-modified polyacrylate, epichlorohydrin, and N,N-dimethylformamide according to a mass ratio of 1:0.3:30, heat up to 70 °C and stir for 6 h, precipitate with pure water, filter, wash, and dry to obtain modified polyacrylate;

[0043] (3) Mix silicon dioxide and ethanol, adjust the pH to 4 with 40 wt% hydrochloric acid solution, add 3-mercaptopropyltrimethoxysilane and ultrasonically mix for 10 min, then heat up to 80 °C and stir for 5 h, filter, wash, and dry to obtain pretreated silicon dioxide; The mass ratio of silicon dioxide, ethanol, and 3-mercaptopropyltrimethoxysilane is 1:20:0.3; Mix pretreated silicon dioxide, dichloromethane, 4-(allyloxy)-2,2,6,6-tetramethylpiperidine, and dimethylphenylphosphine according to a mass ratio of 1:30:0.5:0.02, heat up to 40 °C and react for 10 h, filter, wash, and dry to obtain pre-modified silicon dioxide; Mix pre-modified silicon dioxide, dimethylaminopyridine, triethylamine, dichloromethane, and methacrylic anhydride according to a mass ratio of 1:0.2:3:60:2, stir at room temperature for 10 h, filter, wash with saturated sodium carbonate solution, and dry to obtain vinyl silicon dioxide;

[0044] (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;

[0045] (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.

[0046] Comparative Example 1:

[0047] 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.

[0048] Comparative Example 2:

[0049] 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.

[0050] Comparative Example 3:

[0051] 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.

[0052] Test Example 1:

[0053] Antibacterial performance test:

[0054] 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.

[0055] Table 1

[0056]

[0057] 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.

[0058] 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.

[0059] Test Example 2:

[0060] Mechanical properties test:

[0061] 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.

[0062] Anti-aging performance test:

[0063] Test method: The sample is placed in a thermal-oxidative aging oven for aging. The aging time is 480 h, the aging temperature is 60 °C, and the relative humidity is 55%. The aged film is tested according to the test method for mechanical properties. The results are shown in Table 2.

[0064] Table 2

[0065]

[0066] From the comparison of the experimental data of Examples 1-3 and Comparative Examples 1-3 in Table 2, it can be found that the protective coating for the restraint cord inside the aviation oxygen supply mask pipeline prepared by the present invention has good mechanical properties and anti-aging properties.

[0067] The mechanical properties of Examples 1-3 are better than those of Comparative Examples 1-3, and the anti-aging properties of Examples 1-3 are better than those of Comparative Example 2, indicating that after the reaction of the acrylate polymer with acyl chloride and potassium thiocyanate, and then with 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazol-2-amine, the epoxy groups can be introduced by the dimethylamino groups on epoxy chloropropane and 5-[4-(dimethylamino)phenyl]-1,3,4-oxadiazol-2-amine; reacting silica with vinyl groups on the surface with 4-(allyloxy)-2,2,6,6-tetramethylpiperidine, and then grafting vinyl groups by reacting with methacrylic anhydride, and under the action of n-butyllithium, anionic polymerization with styrene and butadiene is carried out to generate a styrene-butadiene-styrene block polymer with good toughness, endowing the material with good toughness, and using epoxy chloropropane as a capping agent to introduce epoxy functional groups; 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 photoinitiators to form a more complex crosslinked network, further enhancing the crosslinking.

[0068] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

Claims

1. A preparation method of a protective coating for a restraining rope inside an aviation oxygen supply 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) 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 5-7 hours, filter, wash and dry to obtain pretreated silica; the mass ratio of silica, ethanol and mercaptopropyl trimethoxysilane is 1:(10-20):(0.2-0.3); mix pretreated silica, dichloromethane, 4-(allyloxy)-2,2,6,6-tetramethylpiperidine and dimethylphenylphosphine in a mass ratio of 1:( 20-30):(0.3-0.5):(0.01-0.02), heat to 40-50°C and react for 10-12h, 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:(0.1-0.2):(2-3):(50-60):(1-2), stir at room temperature for 10-12h, filter, wash with saturated sodium carbonate solution and dry to obtain vinyl silica; (4) Weigh styrene, vinyl silica, cyclohexane, n-butyl lithium, propylene oxide, and epichlorohydrin in a mass ratio of 2:(5-6):(35-40):0.04:(0.03-0.05):(0.1-0.2); under nitrogen protection, mix half of the styrene, vinyl silica, and cyclohexane and heat to 60°C, add one-fourth of n-butyl lithium for 3-5 minutes, then add the remaining n-butyl lithium and react for 30-40 minutes, add butadiene 1-2 times the mass of styrene and continue to react for 35-45 minutes, then add the remaining styrene and react for 30-40 minutes, add propylene oxide and react for 10 minutes, add epichlorohydrin and react for 15 minutes, filter, wash, and dry 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 preparation method of a protective coating for a restraint cord inside an aviation oxygen supply mask pipeline according to claim 1, characterized in that, The preparation method of the acryloyl chloride polyacrylate described in step (1) is as follows: Mix acrylic acid, methyl methacrylate, butyl acrylate, azobisisobutyronitrile, and isopropanol in a mass ratio of 1:(0.7 - 0.8):(0.5 - 0.6):(0.01 - 0.02):(20 - 30), heat up to 82 - 85 °C, reflux and stir for 2 - 3 h, and obtain polyacrylate through rotary evaporation under reduced pressure and vacuum drying; Mix the polyacrylate, thionyl chloride, and N,N - dimethylformamide in a mass ratio of 1:(5 - 6):(0.2 - 0.3), heat up to 65 - 75 °C, react for 40 - 50 min, and obtain acryloyl chloride polyacrylate through distillation under reduced pressure.

3. The preparation method of a protective coating for the restraining rope in the pipeline of an aviation oxygen supply mask according to claim 1, characterized in that, The preparation method of the modified polyacrylate described in step (2) is as follows: Under nitrogen protection, mix the acryloyl chloride polyacrylate, 10 wt% potassium thiocyanate aqueous solution, N,N - dimethylformamide, and triethylamine in a mass ratio of 1:(0.5 - 0.6):(20 - 30):(0.3 - 0.5) for 30 - 40 min, then filter and retain the filtrate. Add 5 - [4 - (dimethylamino)phenyl]-1,3,4 - oxadiazol - 2 - amine with a mass 0.6 - 0.8 times that of the acryloyl chloride polyacrylate to the filtrate, react at 60 - 70 °C for 3 - 5 h, cool to room temperature, and obtain pre - modified polyacrylate through rotary evaporation under reduced pressure; Mix the pre - modified polyacrylate, epichlorohydrin, and N,N - dimethylformamide in a mass ratio of 1:(0.2 - 0.3):(20 - 30), heat up to 70 - 80 °C, stir for 6 - 8 h, and obtain modified polyacrylate through precipitation with pure water, filtration, washing, and drying.

4. The preparation method of a protective coating for the restraining rope inside the pipeline of an aviation oxygen supply mask according to claim 1, characterized in that, The particle size of the silicon dioxide described in step (3) is 200 nm.

5. The preparation method of a protective coating for a restraint cord inside an aviation oxygen supply mask pipeline according to claim 1, characterized in that, The tackifying resin described in step (5) is Arakawa rosin ester GA - 90; the wetting and dispersing agent is Disperbyk - 190; the defoaming agent is BYK1758; the emulsifier is OP - 10; the cationic photoinitiator is cationic photoinitiator 250.

6. An anti - corrosion coating for the restraint rope inside the aviation oxygen supply mask pipeline, prepared by the preparation method of the anti - corrosion coating for the restraint rope inside the aviation oxygen supply mask pipeline according to any one of claims 1 - 5.

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