A wear-resistant coating and its preparation method

Abstract

The present invention relates to the technical field of coatings, and specifically relates to a wear-resistant coating and a preparation method thereof, comprising the following raw materials: a solvent, a modified resin, a filler, a dispersant, an antifoaming agent, a hardening agent, and a curing agent; the modified resin is prepared from oil-repellent particles, B resin, and a silane coupling agent; the oil-repellent particles are prepared from silicon dioxide, tetraethyl orthosilicate, 1H,1H,2H,2H-heptadecafluorodecyltrichlorosilane, and diatomaceous earth, and it can improve the oil resistance of the coating; the filler is obtained by mixing modified graphite, silicon carbide, silicon dioxide, molybdenum disulfide, and iron(III) oxide in a specific ratio, and it can improve the self-lubricity, mechanical properties, and oil resistance of the coating; the hardening agent is pentaerythritol tetrakis(3-mercaptopropionate) grafted with 1H,1H,2H,2H-heptadecafluorodecyl acrylate, and it will undergo chemical cross-linking with other components to improve the wear resistance of the coating; therefore, the wear-resistant coating of the present invention has good oil resistance, wear resistance, and broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular, to a wear-resistant coating and a preparation method thereof. Background Art

[0002] As a protective functional coating, the wear-resistant coating has the characteristics of low surface friction coefficient of the coating, large load-bearing capacity, strong resistance to mechanical force, etc. Therefore, when subjected to external forces, it can effectively reduce the friction between interfaces, reduce the intensity of wear and the force of resistance to wear, play a role in protecting the substrate and extending its service life, and is widely used in the fields of aerospace vehicles, vehicles, ships, instruments, machine tool industries, etc. With the sharp increase in the demand for wear-resistant coatings in the energy field, especially in wind turbine blades, nuclear reactor containment vessels, dam structures, turbines, etc., a large number of applications have also been obtained. A large number of literatures show that at present, domestic and foreign wear-resistant coatings mainly achieve their wear-resistant effects through two methods:

[0003] One is to add lubricants such as polytetrafluoroethylene powder, graphite, molybdenum disulfide, graphene and its derivatives to the coating, so that the coating has good lubrication conditions, and transfer the friction pair to the internal friction of the lubricant when the interface contacts, thereby reducing the friction between the contact surfaces and achieving lubrication and friction reduction; the other is to add wear-resistant aggregates such as aluminum oxide, silicon carbide, and silicon dioxide to the coating to improve the strength of the coating, which can effectively resist frequent wear, high-speed erosion, and violent collision from the outside; in addition, the matrix resin also plays a decisive role in the wear resistance of the coating. A wear-resistant epoxy resin coating and a preparation method thereof disclosed in the patent technical literature CN118126602A include the following components in parts by mass: 25-30 parts of modified epoxy resin, 13-18 parts of waterborne saturated polyester modified silicone resin, 1-5 parts of expanded graphite, 2-7 parts of polyimide, 5-9 parts of modified mica powder, 4-7 parts of modified silicon dioxide, 1-4 parts of nano titanium nitride, 0.5-2.5 parts of molybdenum disulfide, 1-2 parts of curing agent, 1-3 parts of dispersant, 1-2 parts of thickener and 40-45 parts of deionized water; this patent takes into account various methods.

[0004] However, these existing technologies still have not solved the problems that the anti-permeability of the wear-resistant coating is not ideal, it is easy to seep oil, and the wear resistance still needs to be improved.

[0005] Therefore, according to the above related technologies, it is urgent to develop a wear-resistant coating and a preparation method thereof. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a wear-resistant coating and a preparation method thereof to solve the problem that the oil resistance and wear resistance of the wear-resistant coating in the existing technology are relatively poor.

[0007] Based on the above purpose, the present invention provides a wear-resistant coating and a preparation method thereof.

[0008] A wear-resistant coating, comprising raw materials in the following parts by mass: 25 - 30 parts of a solvent, 50 - 60 parts of a modified resin, 15 - 20 parts of a filler, 1.5 - 2 parts of a dispersant, 0.3 - 0.5 parts of an antifoaming agent, 13 - 15 parts of a hardening agent, and 8 - 10 parts of a curing agent;

[0009] The modified resin is prepared from oleophobic particles, methyl methacrylate, isooctyl methacrylate, 1H,1H,2H,2H - heptadecafluorodecyl acrylate, a silane coupling agent, and ethanol;

[0010] The oleophobic particles are prepared from silicon dioxide, tetraethyl orthosilicate, heptadecafluorodecyltrichlorosilane, and diatomite;

[0011] The filler is obtained by mixing modified graphite, silicon carbide, silicon dioxide, molybdenum disulfide, and iron(III) oxide in a mass ratio of 3 - 5:1 - 2:7 - 10:2 - 4:2 - 4;

[0012] The modified graphite is prepared from graphite, concentrated sulfuric acid, sodium nitrate, potassium permanganate, a surfactant, and a wetting agent;

[0013] The hardening agent is tetra(3 - mercaptopropionic acid) pentaerythritol ester grafted with 1H,1H,2H,2H - heptadecafluorodecyl acrylate.

[0014] Preferably, the solvent is obtained by mixing xylene, butyl acetate, ethanol, and n - butanol in a mass ratio of 8 - 10:28 - 30:12 - 16:2 - 4.

[0015] Preferably, the preparation method of the modified resin is as follows:

[0016] Step A1: Add water, silicon dioxide, and ammonia to ethanol in sequence, stir evenly, then add tetraethyl orthosilicate, stir evenly again, and then add a mixed solution of heptadecafluorodecyltrichlorosilane and n - hexane, control the temperature and stir to obtain resin A;

[0017] Step A2: Add resin A to diatomite, react at 78 - 80 °C for 23 - 25 h, then grind and sieve with a 180 - 200 - mesh fine screen to obtain oleophobic particles;

[0018] Step A3: Under a nitrogen atmosphere, add methyl methacrylate, isooctyl methacrylate, a silane coupling agent, and 1H,1H,2H,2H - heptadecafluorodecyl acrylate to butyl acetate, stir evenly at 116 - 118 °C, then add a mixed solution of di - tert - butyl peroxide and ethanol dropwise at 2 - 4 drops / second, and react for 8 - 9 h to obtain resin B;

[0019] Step A4: Add oil-repellent particles and silane coupling agent to B resin, stir evenly and adjust the pH to 5 - 7, then add ethanol and stir for 60 - 70 min to obtain the modified resin.

[0020] Preferably, in step A1, the mass ratio of ethanol, water, silicon dioxide, ammonia water, tetraethyl orthosilicate, 1H,1H,2H,2H - heptadecafluorodecyltrichlorosilane, and n - hexane is 80 - 85:8 - 10:8 - 10:4 - 5:0.5 - 0.6:5 - 6:20 - 25; the speed during temperature - controlled stirring is 1000 - 1100 rmp, the time is 23 - 25 h, and the temperature is 65 - 70 °C.

[0021] Preferably, in step A2, the mass ratio of diatomite to A resin is 10 - 12:8 - 10; in step A3, the mass ratio of butyl acetate, methyl methacrylate, isooctyl methacrylate, silane coupling agent, 1H,1H,2H,2H - heptadecafluorodecyl acrylate, di - tert - butyl peroxide, and ethanol is 45 - 50:10 - 12:7.3 - 7.5:1.8 - 2:28 - 30:0.3 - 0.5:8 - 10; in step A4, the mass ratio of B resin, oil - repellent particles, silane coupling agent, and ethanol is 30 - 32:8 - 10:2 - 3:10 - 15.

[0022] Preferably, the preparation method of the modified graphite is as follows:

[0023] Step B1: Mix concentrated sulfuric acid and sodium nitrate evenly, then add graphite, and then add potassium permanganate dropwise at 58 - 60 °C at a rate of 2 - 4 drops per second and react for 6 - 8 h to obtain oxidized graphite;

[0024] Step B2: Mix the surfactant and wetting agent evenly, then add oxidized graphite, stir at 58 - 60 °C for 4 - 5 h, filter and dry to obtain modified graphite.

[0025] Preferably, in step B1, the mass ratio of graphite to concentrated sulfuric acid, sodium nitrate, and potassium permanganate is 5 - 5.5:4.8 - 5:10 - 12:4.8 - 5; in step B2, the mass ratio of the surfactant, modifier, and oxidized graphite is 2 - 2.5:2 - 2.5:20 - 25.

[0026] Preferably, the preparation method of the hardening agent is as follows:

[0027] Mix pentaerythritol tetra(3 - mercaptopropionate), dibutylamine, and acetone evenly, then add dropwise a mixed solution of 1H,1H,2H,2H - heptadecafluorodecyl acrylate and acetone at a rate of 2 - 4 drops per second, stir at 1000 - 1100 rmp for 15 - 17 h, and remove acetone to obtain the hardening agent.

[0028] Preferably, the mass ratio of pentaerythritol tetra(3-mercaptopropionate), dibutylamine, acetone, 1H,1H,2H,2H-heptadecafluorodecyl acrylate and acetone is 4.8 - 5: 0.013 - 0.015: 5 - 5.2: 5.1 - 5.3: 5 - 5.2.

[0029] A preparation method of a wear-resistant coating is as follows:

[0030] Add a modified resin to a solvent and stir for 10 - 15 min. Then add a filler and continue to stir for 5 - 10 min. Subsequently, add a dispersant, an antifoaming agent, a hardening agent and a curing agent in sequence, and stir for another 10 - 15 min to obtain the wear-resistant coating.

[0031] Advantages of the present invention:

[0032] The present invention provides a wear-resistant coating and a preparation method thereof. By mixing modified graphite with silicon carbide, silicon dioxide, molybdenum disulfide, and iron(III) oxide in a specific ratio, the lubrication and drag reduction ability, the ability of persistent and stable lubrication, mechanical properties and oil resistance of the coating are maximally improved; the hardening agent and the modified resin can reduce the surface rearrangement caused by the attachment of oil stains, making the fluoropolymer have a very low adhesion tendency and endowing the coating with excellent hydrophobic and oleophobic properties; the siloxane monomers in each component can improve the mechanical properties of the coating; the Si-O bond in the organosilicon polymer makes the coating have a low surface energy and a low elastic modulus, which can further reduce the attachment of pollutants; and the oleophobic units of the oleophobic particles will be closely arranged to prevent the hydrophilic units from being attracted back to the outer surface by other polar groups, thereby improving the oil resistance and waterproofness of the coating; the hardening agent also contains mercapto groups that can undergo chemical cross-linking with other components containing carbon-carbon double bonds through thiol-ene click reaction to improve the wear resistance of the coating.

[0033] Therefore, compared with the prior art, the wear-resistant coating prepared by the present invention has relatively good oil resistance, wear resistance and broad application prospects. Specific embodiments

[0034] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with specific embodiments.

[0035] The sources and properties of some raw materials used in the present invention are as follows:

[0036] Graphite (particle size 10 nm) was purchased from Jiangsu Xianfeng Nano Materials Technology Co., Ltd.; the surfactant was purchased from Hubei Jusheng Technology Co., Ltd., CAS: 85854-32-6; the wetting agent was purchased from Linyi Guoli Chemical Industry Co., Ltd., CAS: 577-11-7; pentaerythritol tetra(3-mercaptopropionate) was purchased from Shanghai Yuanye Bio-Technology Co., Ltd., CAS: 7575-23-7; 1H,1H,2H,2H-heptadecafluorodecyl acrylate was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., CAS: 27905-45-9; heptadecafluorodecyltrichlorosilane was purchased from Hubei Jusheng Technology Co., Ltd., CAS: 78560-44-8; methyl methacrylate was purchased from Shandong Jinyueyuan New Materials Co., Ltd., CAS: 80-62-6; isooctyl methacrylate was purchased from Shandong Yonglida New Materials Technology Co., Ltd., CAS: 28675-80-1; the silane coupling agent was purchased from Shanghai Yuanye Bio-Technology Co., Ltd., CAS: 2530-85-0; di-tert-butyl peroxide was purchased from Jinan Hongteng Weiye New Materials Co., Ltd., CAS: 110-05-4; the dispersant was purchased from Anhui Shengyuan Chemical Industry Co., Ltd., CAS: 36290-04-7; the defoamer was purchased from Linyi Guoli Chemical Industry Co., Ltd., CAS: 993-11-6; the curing agent was purchased from Shandong Zhengxing New Materials Co., Ltd., CAS: 85-44-9.

[0037] Example 1: A preparation method of a wear-resistant coating, comprising the following steps:

[0038] S1: Mix 5 g of concentrated sulfuric acid with a concentration of 98% and 4.8 g of sodium nitrate, add 10 g of graphite, and add 4.8 g of potassium permanganate dropwise at 58 °C at a rate of 2 drops per second and react for 6 h to obtain graphite oxide;

[0039] S2: Mix 2 g of the surfactant and 2 g of the wetting agent evenly, then add 20 g of graphite oxide, stir at 58 °C for 4 h, filter and dry to obtain modified graphite;

[0040] S3: Mix 3 g of modified graphene, 1 g of silicon carbide, 7 g of silicon dioxide, 2 g of molybdenum disulfide and 2 g of iron(III) oxide evenly to obtain a filler;

[0041] S4: Mix 4.8 g of pentaerythritol tetra(3-mercaptopropionate), 0.013 g of dibutylamine and 5 g of acetone evenly, then add dropwise a mixed solution of 5.1 g of 1H,1H,2H,2H-heptadecafluorodecyl acrylate and 5 g of acetone at a rate of 2 drops per second, stir at 1000 rmp for 15 h, and remove acetone to obtain a hardening agent;

[0042] S5: Add 8 g of water, 8 g of silicon dioxide, and 4 g of ammonia water to 80 g of ethanol in sequence. After stirring evenly, add 0.5 g of tetraethyl orthosilicate. After stirring evenly again, add a mixture of 5 g of 1H,1H,2H,2H-heptadecafluorodecyltrichlorosilane and 20 g of n-hexane. Stir at 1000 rmp at 65 °C for 23 h to obtain Resin A;

[0043] S6: Add 8 g of Resin A to 10 g of diatomite, react at 78 °C for 23 h, then grind and sieve through a 180-mesh fine screen to obtain oil-repellent particles;

[0044] S7: Under a nitrogen atmosphere, add 10 g of methyl methacrylate, 7.3 g of isooctyl methacrylate, 1.8 g of silane coupling agent, and 28 g of 1H,1H,2H,2H-heptadecafluorodecyl acrylate to 45 g of butyl acetate, stir evenly at 116 °C, then add a mixture of 0.3 g of di-tert-butyl peroxide and 8 g of ethanol dropwise at 2 drops / second. After reacting for 8 h, obtain Resin B;

[0045] S8: Add 8 g of oil-repellent particles and 2 g of silane coupling agent to 30 g of Resin B, stir evenly and adjust the pH to 5, then add 10 g of ethanol and stir for 60 min to obtain a modified resin;

[0046] S9: Add 50 g of the modified resin to 25 g of solvent, stir for 10 min, then add 15 g of filler, continue to stir for 5 min, and then add 1.5 g of dispersant, 0.3 g of defoamer, 13 g of hardener, and 8 g of curing agent in sequence, and stir for another 10 min to obtain a wear-resistant coating.

[0047] Example 2: A method for preparing a wear-resistant coating, comprising the following steps:

[0048] S1: Mix 5.3 g of concentrated sulfuric acid with a concentration of 98% and 4.9 g of sodium nitrate, add 11 g of graphite, and add 4.9 g of potassium permanganate dropwise at 3 drops / second at 59 °C and react for 7 h to obtain graphite oxide;

[0049] S2: Mix 2.3 g of surfactant and 2.3 g of wetting agent evenly, then add 23 g of graphite oxide, stir at 59 °C for 4.5 h, filter and dry to obtain modified graphite;

[0050] S3: Mix 4 g of modified graphene, 1.5 g of silicon carbide, 9 g of silicon dioxide, 3 g of molybdenum disulfide, and 3 g of iron(III) oxide evenly to obtain a filler;

[0051] S4: Mix 4.9 g of pentaerythritol tetrakis(3-mercaptopropionate), 0.014 g of dibutylamine, and 5.1 g of acetone uniformly. Then, add a mixed solution of 5.2 g of 1H,1H,2H,2H-heptadecafluorodecyl acrylate and 5.1 g of acetone dropwise at a rate of 3 drops per second, stir at 1050 rmp for 16 h, and remove acetone to obtain a hardening agent;

[0052] S5: Add 9 g of water, 9 g of silicon dioxide, and 4.5 g of ammonia water to 83 g of ethanol in sequence, stir uniformly, then add 0.55 g of tetraethyl orthosilicate, stir uniformly again, and then add a mixed solution of 5.5 g of heptadecafluorodecyltrichlorosilane and 23 g of n-hexane. Stir at 68 °C at 1050 rmp for 24 h to obtain Resin A;

[0053] S6: Add 9 g of Resin A to 11 g of diatomite, react at 79 °C for 24 h, then grind and sieve through a 190-mesh fine screen to obtain oil-repellent particles;

[0054] S7: Under a nitrogen atmosphere, add 11 g of methyl methacrylate, 7.4 g of isooctyl methacrylate, 1.9 g of silane coupling agent, and 29 g of 1H,1H,2H,2H-heptadecafluorodecyl acrylate to 48 g of butyl acetate, stir uniformly at 117 °C, then add a mixed solution of 0.4 g of di-tert-butyl peroxide and 9 g of ethanol dropwise at a rate of 3 drops per second, and react for 8.5 h to obtain Resin B;

[0055] S8: Add 9 g of oil-repellent particles and 2.5 g of silane coupling agent to 31 g of Resin B, stir uniformly and adjust the pH to 6, then add 13 g of ethanol, and stir for 65 min to obtain a modified resin;

[0056] S9: Add 55 g of the modified resin to 28 g of a solvent, stir for 13 min, then add 18 g of a filler, continue to stir for 8 min, and then add 1.8 g of a dispersant, 0.4 g of an antifoaming agent, 14 g of a hardening agent, and 9 g of a curing agent in sequence, and stir for another 13 min to obtain a wear-resistant coating.

[0057] Example 3: A method for preparing a wear-resistant coating, comprising the following steps:

[0058] S1: Mix 5.5 g of concentrated sulfuric acid with a concentration of 98% and 5 g of sodium nitrate, then add 12 g of graphite, and add 5 g of potassium permanganate dropwise at a rate of 4 drops per second at 60 °C and react for 8 h to obtain graphite oxide;

[0059] S2: Mix 2.5 g of a surfactant and 2.5 g of a wetting agent uniformly, then add 25 g of graphite oxide, stir at 60 °C for 5 h, filter and dry to obtain modified graphite;

[0060] S3: Mix 5 g of modified graphene, 2 g of silicon carbide, 10 g of silicon dioxide, 4 g of molybdenum disulfide, and 4 g of iron(III) oxide evenly to obtain a filler;

[0061] S4: Mix 5 g of pentaerythritol tetrakis(3-mercaptopropionate), 0.015 g of dibutylamine, and 5.2 g of acetone evenly. Then, add a mixed solution of 5.3 g of 1H,1H,2H,2H-heptadecafluorodecyl acrylate and 5.2 g of acetone dropwise at a rate of 4 drops per second, and stir at 1100 rmp for 17 h. Remove acetone to obtain a hardening agent;

[0062] S5: Add 10 g of water, 10 g of silicon dioxide, and 5 g of ammonia water to 85 g of ethanol in sequence. After stirring evenly, add 0.6 g of tetraethyl orthosilicate, stir evenly again, and then add a mixed solution of 6 g of heptadecafluorodecyltrichlorosilane and 25 g of n-hexane. Stir at 70 °C and 1100 rmp for 25 h to obtain Resin A;

[0063] S6: Add 10 g of Resin A to 12 g of diatomite, react at 80 °C for 25 h, then grind and sieve through a 200-mesh fine sieve to obtain oil-repellent particles;

[0064] S7: Under a nitrogen atmosphere, add 12 g of methyl methacrylate, 7.5 g of isooctyl methacrylate, 2 g of silane coupling agent, and 30 g of 1H,1H,2H,2H-heptadecafluorodecyl acrylate to 50 g of butyl acetate, stir evenly at 118 °C, then add a mixed solution of 0.5 g of di-tert-butyl peroxide and 10 g of ethanol dropwise at a rate of 4 drops per second, and react for 9 h to obtain Resin B;

[0065] S8: Add 10 g of oil-repellent particles and 3 g of silane coupling agent to 32 g of Resin B, stir evenly and adjust the pH to 7, then add 15 g of ethanol, and stir for 70 min to obtain a modified resin;

[0066] S9: Add 60 g of the modified resin to 30 g of a solvent, stir for 15 min, then add 20 g of the filler, continue to stir for 10 min, and then add 2 g of a dispersant, 0.5 g of an antifoaming agent, 15 g of the hardening agent, and 10 g of a curing agent in sequence, and stir for another 15 min to obtain a wear-resistant coating.

[0067] Comparative Example 1:

[0068] In this comparative example, compared with Example 1, only "modified graphite" is replaced with "graphite", and the rest of the steps and parameters are the same. This comparative example will not be repeated here, and a wear-resistant coating is finally obtained.

[0069] Comparative Example 2:

[0070] In this comparative example, compared with Example 1, iron(III) oxide is not added, and the rest of the steps and parameters are the same. This comparative example will not be repeated here, and a wear-resistant coating is finally obtained.

[0071] Comparative Example 3:

[0072] In this comparative example, compared with Example 1, molybdenum disulfide was not added during the preparation of the filling material, and the remaining steps and parameters were the same. This comparative example will not be repeated here, and finally a wear-resistant coating was obtained.

[0073] Comparative Example 4:

[0074] In this comparative example, compared with Example 1, only "3 g of modified graphene, 1 g of silicon carbide, 7 g of silicon dioxide, 2 molybdenum disulfide and 2 g of ferric oxide" was replaced with "3 g of modified graphene, 1 g of silicon carbide, 7 g of silicon dioxide, 0.5 g of molybdenum disulfide and 3.5 g of ferric oxide", and the remaining steps and parameters were the same. This comparative example will not be repeated here, and finally a wear-resistant coating was obtained.

[0075] Comparative Example 5:

[0076] In this comparative example, compared with Example 1, oil-repellent particles were not added during the preparation of the modified coating, and the remaining steps and parameters were the same. This comparative example will not be repeated here, and finally a wear-resistant coating was obtained.

[0077] Comparative Example 6:

[0078] In this comparative example, compared with Example 1, only "modified resin" was replaced with "acrylic resin", and the remaining steps and parameters were the same. This comparative example will not be repeated here, and finally a wear-resistant coating was obtained.

[0079] Comparative Example 7:

[0080] In this comparative example, compared with Example 1, a hardening agent was not added, and the remaining steps and parameters were the same. This comparative example will not be repeated here, and finally a wear-resistant coating was obtained.

[0081] Performance test:

[0082] Take 10 steel plates with dimensions of 120 mm × 50 mm, remove the rust on the surface with 1200-mesh sandpaper, then ultrasonically clean the steel plates with absolute ethanol, and dry them with a hair dryer for standby; place the treated steel plates on the test bench, and use a wire bar coater with a specification of 100 μm (Oushi Precision Tools Co., Ltd.) to coat the wear-resistant coatings prepared in Examples 1-3 and Comparative Examples 1-7 on each group of steel plates, and the wet film thickness is 100 μm; after coating the coating, place the sample flat on the test bench, dry it at 125 °C for 10 h, and obtain a wear-resistant coating sample, and perform performance tests on the prepared wear-resistant coating samples:

[0083] Determination of adhesion:

[0084] Refer to the test standard of GB / T9286-2021 "Paints and varnishes - Cross-cut test". Place the wear-resistant coating sample on a flat and hard operating table. Use a cross-cut blade to make uniform cuts in two mutually perpendicular directions respectively. Pay attention to applying force evenly and cutting smoothly without trembling during this process, and the cut should penetrate the coating and touch the metal plate. After cutting, gently wipe along the diagonal direction of the grid with a soft brush. Then, paste a special 3M tape on the entire grid formed by the cuts. Press firmly with fingers to ensure good contact between the tape and the coating. When peeling off the tape, the tape should form a 60° angle with the coating and be peeled off smoothly and quickly within 1 s. Evaluate the coating adhesion grade by observing the size of the peeled area, which is divided into grades 0 - 5 in total. The adhesion is the strongest at grade 0 and the weakest at grade 5. Conduct the adhesion (grade) test on the samples prepared from the wear-resistant coatings prepared in Examples 1 - 3 and Comparative Examples 1 - 7 according to this test standard;

[0085] Determination of adhesion after oil immersion:

[0086] Refer to the test standard of GB / T9286-2021 "Paints and varnishes - Cross-cut test". According to the above method for determining adhesion, conduct the adhesion (grade) test on the samples prepared from the wear-resistant coatings prepared in Examples 1 - 3 and Comparative Examples 1 - 7 after being immersed in a mixed solution of soybean oil and hexadecane with a volume ratio of 3:1 at 25°C for 90 days;

[0087] Determination of corrosion resistance:

[0088] Refer to the test standard of GB / T10125-2021 "Artificial atmosphere corrosion test - Salt spray test". Use epoxy putty to seal the edges of the wear-resistant coating samples, and then place them in a salt spray test chamber (JAY-1127, Zhuhai Jiayi Testing Equipment Co., Ltd.). At 35°C, conduct a 24h salt spray and 24h drying cycle test with a sodium chloride solution with pH = 6.5 - 7.2 and a concentration of 5%. Observe the samples every 48h and record the test duration for each sample to show red rust. When the last sample shows red rust, the neutral salt spray test ends. Conduct the corrosion resistance (h) test on the samples prepared from the wear-resistant coatings prepared in Examples 1 - 3 and Comparative Examples 1 - 7 according to this test standard;

[0089] Determination of hardness:

[0090] According to the measurement standard of GB / T6739-2006 "Paints and varnishes - Determination of film hardness by pencil test", a cylindrical lead core with a length of about 3 mm is used, with a load of 750 g. Push the experimental instrument forward and downward at a speed of 1 mm / s at an angle of 45° for 10 mm, and repeat the scratching five times; for each scratch, draw a circle with the lead core vertically against 400# water sandpaper to re-grind the tip of the pencil lead until the tip of the pencil is ground into a flat surface with sharp edges. In the five-scratch test, the pencil hardness of the coating is represented by the hardest pencil hardness without scratching through or with only one scratch through to the bottom coating. The hardness is divided into 20 grades from soft to hard: 9B, 8B, 7B, 6B, 5B, 4B, 3B, 2B, B, BH, F, H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, 9H; according to this test standard, hardness tests are carried out on the samples prepared from the wear-resistant coatings prepared in Examples 1 - 3 and Comparative Examples 1 - 7;

[0091] Determination of abrasion resistance:

[0092] According to the test standard of ASTM-D4060-19 "Standard Test Method for Abrasion Resistance of Organic Coatings Using Taber Abraser", the abrasion resistance of the coating is measured by a grinding machine at a turntable speed of 60 r / min, a rubber grinding wheel model of CS-10, a load of 1 kg, and 5000 revolutions. Before the test and after every 500 revolutions, the rubber grinding wheel is trimmed with a No.S-11 abrasive sheet for 50 revolutions to maintain the surface roughness of the grinding wheel; before the test, the coating is abraded for 50 revolutions and then the sample is weighed as the initial count; after a cumulative abrasion of 5000 revolutions, the abrasion resistance is determined by the weight difference of the coating before and after abrasion; according to this test standard, abrasion resistance tests are carried out on the samples prepared from the wear-resistant coatings prepared in Examples 1 - 3 and Comparative Examples 1 - 7;

[0093] Determination of oil resistance after abrasion:

[0094] According to the measurement standard of QJ990.1-1986 "Coating Inspection Method - Coating Oil Resistance Inspection Method", at 25°C, 2 / 3 of the coating is immersed in a mixed solution of soybean oil and cetane with a volume ratio of 3:1, and the mixed solution is replaced every 30 days. Take it out every 10 days to observe the area of oil stains adhered to the coating surface and whether there are phenomena such as blistering on the coating, and test the wettability of water droplets and oil droplets in the non-adhered area. When the area of oil stains adhered in the immersed area is greater than 1 / 2, the coating is considered to have failed, and the number of days required is recorded as the oil resistance of the coating; according to this test standard, the determination of oil resistance (days) after abrasion is carried out on the samples prepared from the wear-resistant coatings prepared in Examples 1 - 3 and Comparative Examples 1 - 7 after abrasion resistance measurement;

[0095] Determination of friction coefficient:

[0096] Refer to the test standard of GB / T10006-1988 "Determination Method of Coefficient of Friction of Plastic Films and Sheets". Put the well-cured sample plate into a friction and wear testing machine (M-2000, Zhangjiakou Xuanhua Kehua Testing Machine Manufacturing Co., Ltd.). Set specific rotation speed, load, test temperature, time, etc. on the computer and start the experiment. The result obtained from the experiment is the average coefficient of friction. Measure the coefficient of friction of the sample plates prepared with the wear-resistant coatings prepared in Examples 1-3 and Comparative Examples 1-7 according to this test standard;

[0097] Determination of impact resistance:

[0098] Refer to the test standard of GB / T20624.2-2006 "Paints and varnishes - Rapid impact (impact resistance) test, Part 2: Falling weight test (small area punch)". Use a film impact tester (TCJ-II, Shanghai Leao Testing Instrument Co., Ltd.) with a hammer mass of 1 kg to test the impact resistance (kg·m) of the sample plates prepared with the wear-resistant coatings prepared in Examples 1-3 and Comparative Examples 1-7; The test results are shown in Table 1;

[0099] Table 1

[0100]

[0101] Data analysis:

[0102] As can be seen from Table 1, the wear-resistant coatings prepared by the present invention have stronger adhesion, corrosion resistance, wear resistance, oil resistance, higher hardness and smaller coefficient of friction. That is, the wear-resistant ability, corrosion-resistant ability, oil-resistant ability and mechanical properties of the wear-resistant coatings prepared by the present invention are better;

[0103] This may be because after the graphite is modified, it has more active groups that can crosslink with other components, enabling it to be well dispersed in the coating. Due to the special structures of the modified graphite and molybdenum disulfide, they have a lower frictional force during sliding. Moreover, molybdenum disulfide can react with iron(III) oxide to form a dense composite layer of iron sulfide and molybdenum dioxide. Therefore, the modified graphite, molybdenum disulfide, and iron(III) oxide in specific proportions in the present invention can maximize the lubrication and drag reduction ability, the ability of long-term stable lubrication, the mechanical properties, and the oil resistance of the coating. The hardener and the perfluoroalkyl groups in the modified resin are enriched on the surface and closely arranged in an oriented manner, with the CF3 groups exposed outside, which can reduce the surface rearrangement caused by the attachment of oil stains, making the fluoropolymer have a very low adhesion tendency. At the same time, the fluorocarbon chains can also cooperate with the polydimethylsiloxane chain segments to endow the coating with excellent hydrophobic and oleophobic properties. The siloxane monomers in each component can produce active silanol groups through hydrolysis. These silanol groups can provide sites for chemical interaction with the substrate and can also condense into a tight network structure among them, thereby forming a tight network structure and further improving the mechanical properties of the coating. The Si-O bond in the organosilicon polymer gives it a low surface energy and a low elastic modulus, which can further reduce the attachment of pollutants. The oleophobic microparticle hydrophilic units in the modified resin are inside, and the oleophobic units are on the outside. And due to the pinning effect of the deposited fluorosilane on the surface, the oleophobic units will be closely arranged to prevent the hydrophilic units from being attracted back to the outer surface by other polar groups. Therefore, it can not only improve the oil resistance of the coating but also improve its waterproofness. The hardener also contains mercapto groups that can undergo chemical crosslinking with other components containing carbon-carbon double bonds through thiol-ene click reaction to improve the wear resistance of the coating. Due to this special arrangement form layer by layer from the inside to the outside and various tight connection arrangements, the coating has very good oil resistance, and the oil resistance remains very remarkable even after the coating is worn.

[0104] In Comparative Example 1, "modified graphite" was replaced with "graphite"; in Comparative Example 2, iron(III) oxide was not added; in Comparative Example 3, molybdenum disulfide was not added; in Comparative Example 4, the added "3 g of modified graphene, 1 g of silicon carbide, 7 g of silicon dioxide, 2 g of molybdenum disulfide, and 2 g of iron(III) oxide" was replaced with "3 g of modified graphene, 1 g of silicon carbide, 7 g of silicon dioxide, 0.5 g of molybdenum disulfide, and 3.5 g of iron(III) oxide". It can be seen from Table 1 that compared with Example 1, their adhesion after oil immersion, corrosion resistance, hardness, wear resistance, oil resistance after wear, friction coefficient, and impact resistance are all relatively poor. This may be because after graphite is modified, it has more active groups that can crosslink with other components, enabling it to be well dispersed in the coating. Both modified graphite and molybdenum disulfide also have special lamellar structures, so they have lower friction when sliding occurs. Moreover, molybdenum disulfide can react with iron(III) oxide to form a dense composite layer of iron sulfide and molybdenum dioxide. Therefore, the modified graphite, molybdenum disulfide, and iron(III) oxide in specific proportions in the present invention can maximize the lubrication and drag reduction ability, the ability of persistent and stable lubrication, mechanical properties, and oil resistance of the coating;

[0105] In Comparative Example 5, oil-repellent particles were not added during the preparation of the modified coating. It can be seen from Table 1 that compared with Example 1, their adhesion after oil immersion, corrosion resistance, hardness, wear resistance, oil resistance after wear, friction coefficient, and impact resistance are all relatively poor. This may be because the hydrophilic units of the oil-repellent particles in the modified resin are inside and the oil-repellent units are outside. And due to the pinning effect of the deposited fluorosilane on the surface, the oil-repellent units will be closely arranged to prevent the hydrophilic units from being attracted back to the outer surface by other polar groups. Therefore, it can not only improve the oil resistance of the coating but also improve its corrosion resistance;

[0106] In Comparative Example 6, "modified resin" was replaced with "acrylic resin". It can be seen from Table 1 that compared with Example 1, their adhesion after oil immersion, corrosion resistance, hardness, wear resistance, oil resistance after wear, friction coefficient, and impact resistance are all relatively poor. This may be because the perfluoroalkyl groups in the modified resin are enriched on the surface and closely arranged in an oriented manner, with the CF3 groups exposed on the outside, which can reduce the surface rearrangement caused by the adhesion of oil stains, making the fluoropolymer have a very low adhesion tendency; the siloxane monomers therein can produce reactive silicon hydroxyl groups through hydrolysis. These silicon hydroxyl groups can provide sites for chemical interaction with the substrate and can also condense into a tight network structure among them, thereby forming a tight network structure and further improving the mechanical properties of the coating;

[0107] In Comparative Example 7, the hardening agent was not added. As can be seen from Table 1, compared with Example 1, their adhesion after oil immersion, corrosion resistance, hardness, wear resistance, oil resistance after wear, friction coefficient, and impact resistance are all relatively poor. This may be because the hardening agent has both a mercapto group and a fluorocarbon chain. The mercapto group can undergo chemical cross-linking with other components containing carbon-carbon double bonds through the thiol-ene click reaction, improving the hardness, adhesion, and impact resistance of the coating; the fluorocarbon chain can cooperate with the polydimethylsiloxane chain segment to endow the coating with excellent hydrophobic and oleophobic capabilities.

[0108] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention is limited to these examples; under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above, which are not provided in detail for the sake of brevity.

[0109] The present invention aims to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A wear-resistant coating, characterized in that: The invention comprises the following raw materials in parts by weight: 25-30 parts of solvent, 50-60 parts of modified resin, 15-20 parts of filler, 1.5-2 parts of dispersant, 0.3-0.5 parts of defoamer, 13-15 parts of hardener and 8-10 parts of curing agent; The modified resin is prepared from oleophobic particles, methyl methacrylate, isooctyl methacrylate, 1H, 1H, 2H, 2H-heptadecafluorodecyl acrylate, a silane coupling agent and ethanol; The oleophobic particles are prepared from silicon dioxide, tetraethyl orthosilicate, heptadecafluorodecyltrichlorosilane and diatomaceous earth; The filler is obtained by mixing modified graphite, silicon carbide, silicon dioxide, molybdenum sulfide and ferric oxide in a mass ratio of 3-5:1-2:7-10:2-4:2-4; The modified graphite is prepared from graphite, concentrated sulfuric acid, sodium nitrate, potassium permanganate, a surfactant and a wetting agent; The hardener is pentaerythritol tetrakis(3-mercaptopropionic acid) grafted with 1H,1H,2H,2H-heptadecafluorodecyl acrylate.

2. The wear-resistant coating according to claim 1, characterized in that: The solvent is obtained by mixing xylene, butyl acetate, ethanol and n-butanol in a mass ratio of 8-10:28-30:12-16:2-4.

3. The wear-resistant coating according to claim 1, characterized in that: The preparation method of the modified resin is as follows: Step A1: water, silicon dioxide and ammonia water are added to ethanol in sequence, and tetraethyl orthosilicate is added after stirring evenly. After stirring evenly again, a mixed solution of heptadecafluorodecyltrichlorosilane and n-hexane is added, and the mixture is stirred under controlled temperature to obtain resin A; Step A2: adding resin A to diatomaceous earth, reacting at 78-80° C. for 23-25 ​​hours, then grinding and sieving with a 180-200 mesh fine sieve to obtain oleophobic particles; Step A3: under a nitrogen atmosphere, methyl methacrylate, isooctyl methacrylate, a silane coupling agent and 1H, 1H, 2H, 2H-heptadecafluorodecyl acrylate were added to butyl acetate, and the mixture was stirred at 116-118° C., and then a mixed solution of di-tert-butyl peroxide and ethanol was added at a rate of 2-4 seconds / drop, and the mixture was reacted for 8-9 hours to obtain resin B; Step A4: Add oleophobic particles and silane coupling agent to resin B, stir evenly and adjust the pH to 5-7, then add ethanol and stir for 60-70 minutes to obtain modified resin.

4. The wear-resistant coating according to claim 3, characterized in that: The mass ratio of ethanol, water, silicon dioxide, ammonia water, tetraethyl orthosilicate, heptadecafluorodecyltrichlorosilane and n-hexane in step A1 is 80-85:8-10:8-10:4-5:0.5-0.6:5-6:20-25; the speed during the temperature-controlled stirring is 1000-1100 rpm, the time is 23-25h, and the temperature is 65-70°C.

5. The wear-resistant coating according to claim 3, characterized in that: The mass ratio of diatomaceous earth to resin A in step A2 is 10-12:8-10; the mass ratio of butyl acetate, methyl methacrylate, isooctyl methacrylate, silane coupling agent, 1H, 1H, 2H, 2H-heptadecafluorodecyl acrylate, di-tert-butyl peroxide, and ethanol in step A3 is 45-50:10-12:7.3-7.5:1.8-2:28-30:0.3-0.5:8-10; the mass ratio of resin B, oleophobic particles, silane coupling agent, and ethanol in step A4 is 30-32:8-10:2-3:10-15.

6. The wear-resistant coating according to claim 1, characterized in that: The preparation method of the modified graphite is as follows: Step B1: After mixing concentrated sulfuric acid and sodium nitrate evenly, add graphite, then add potassium permanganate at 58-60° C. at a rate of 2-4 seconds / drop and react for 6-8 hours to obtain graphite oxide; Step B2: The surfactant and the wetting agent are mixed evenly, and then graphite oxide is added, stirred at 58-60° C. for 4-5 hours, filtered, and dried to obtain modified graphite.

7. The wear-resistant coating according to claim 6, characterized in that: The mass ratio of the graphite added with concentrated sulfuric acid, sodium nitrate and potassium permanganate in step B1 is 5-5.5:4.8-5:10-12:4.8-5; the mass ratio of the surfactant, modifier and graphite oxide in step B2 is 2-2.5:2-2.5:20-25.

8. The wear-resistant coating according to claim 1, characterized in that: The preparation method of the hardener is as follows: Pentaerythritol tetrakis(3-mercaptopropionic acid), dibutylamine and acetone were mixed evenly, and then a mixed solution of 1H, 1H, 2H, 2H-heptadecafluorodecyl acrylate and acetone was added at 2-4 seconds / drop, and stirred at 1000-1100 rpm for 15-17 hours, and acetone was removed to obtain a hardener.

9. The wear-resistant coating according to claim 8, characterized in that: The mass ratio of pentaerythritol tetrakis(3-mercaptopropionate), dibutylamine, acetone, 1H,1H,2H,2H-heptadecafluorodecyl acrylate and acetone is 4.8-5: 0.013-0.015: 5-5.2: 5.1-5.3: 5-5.

2.

10. A method for preparing a wear-resistant coating according to any one of claims 1 to 9, characterized in that: The preparation method is as follows: Add modified resin to the solvent, stir for 10-15 minutes, then add filler, continue stirring for 5-10 minutes, then add dispersant, defoamer, hardener and curing agent in sequence, and stir for another 10-15 minutes to obtain a wear-resistant coating.

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