Wear-resistant and rust-proof Teflon coating and preparation method thereof

Abstract

The present invention proposes a wear-resistant and rust-proof Teflon coating and a preparation method thereof, belonging to the technical field of coatings. After irradiation, polytetrafluoroethylene micropowder is grafted with glycidyl methacrylate and then reacted with silicon oxide-coated modified Zn / Fe deposited porous alumina nanospheres that have been modified with a silane coupling agent and hydrolyzed. The nanospheres are added to a Teflon primer and stirred and mixed evenly to obtain a wear-resistant and rust-proof Teflon coating. After the coating prepared by the present invention is cured into a film, the coating is dense, has good lubrication conditions and mechanical resistance, and has excellent wear resistance, scratch resistance, medium resistance, high temperature resistance and other properties. It can effectively resist high-wear environments such as sliding friction, impact friction, and cavitation friction. It can not only compensate for the wear defects caused by friction between the two contact surfaces, but also enable the two relatively moving surfaces to have good lubrication and friction reduction effects, thereby solving the problems of friction and wear and protecting the substrate for a long time.

Description

Technical Field

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

[0002] Teflon coating is an industrial coating with polytetrafluoroethylene (PTFE) as its main component. It has many excellent properties, such as non-stickiness, heat resistance, sliding, moisture resistance, wear resistance, and corrosion resistance, which makes it widely used in many industries.

[0003] As a protective coating, wear-resistant coatings feature a low surface friction coefficient, high load bearing capacity, and strong mechanical resistance. These coatings effectively reduce friction between interfaces when subjected to external forces, reducing wear intensity and resistance to wear, thereby protecting the substrate and extending its service life. They are widely used in aerospace, vehicles, ships, instrumentation, machine tool industries, and other fields. In recent years, with increasing attention to renewable energy, demand for wear-resistant coatings in the energy sector has grown dramatically, particularly in wind turbine blades, nuclear reactor containment vessels, dam structures, and turbines.

[0004] At present, wear-resistant coatings at home and abroad mainly achieve their wear-resistant effects in two ways: one is to add lubricants such as graphite, molybdenum disulfide, graphene and its derivatives to the coating to make the coating have good lubrication conditions, and transfer the friction pair to the internal friction of the lubricant during interface contact, thereby reducing the friction between the contact surfaces and achieving lubrication and friction reduction; the second 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 external wear, high-speed erosion, and violent collisions.

[0005] In addition, the matrix resin also plays a decisive role in the wear resistance of the coating.

[0006] Adding hard particles to Teflon coatings to combat wear has been an effective method. However, if the particles are too large, they are difficult to spray evenly and may cause microcracks within the coating. If the particles are too small, the increased surface energy leads to particle agglomeration, preventing uniform mixing. Both of these factors significantly reduce the coating's hydrophobicity and wear stability. Furthermore, the presence of microcracks makes it easier for corrosive media to penetrate, disrupting the coating structure and further impairing its wear resistance. Therefore, improving the dispersibility of the additive and preventing particle agglomeration and cracking near the additive after spraying are key factors in improving the coating's wear resistance. Furthermore, the resulting Teflon coating must also exhibit excellent rust resistance. Summary of the Invention

[0007] The purpose of the present invention is to propose a wear-resistant and rust-proof Teflon coating and a preparation method thereof, which has good lubrication conditions and anti-mechanical effect, excellent wear resistance, scratch resistance, medium resistance, high temperature resistance and other properties, can effectively resist high wear-resistant environments such as sliding friction, impact friction, cavitation friction, etc., can not only compensate for the wear defects caused by friction between the two contact surfaces, but also enable the two relatively moving surfaces to have good lubrication and friction reduction effects, solve the problems of friction and wear, and protect the substrate for a long time.

[0008] The technical solution of the present invention is achieved as follows:

[0009] The present invention provides a method for preparing a wear-resistant and rust-proof Teflon coating, comprising the following steps:

[0010] S1. Preparation of porous alumina nanospheres: Aluminum sulfate and urea are added to water, a porogen is added, the reaction is heated with stirring, the pH of the solution is adjusted, the reaction is continued with stirring, centrifuged, washed, dried, and calcined to obtain porous alumina nanospheres; the mass ratio of the aluminum sulfate, urea, and porogen is 3-5:7-10:0.1-0.2;

[0011] S2. ZnO / Fe2O3 deposition: porous alumina nanospheres were added to water, zinc salt and iron salt were added, stirred and mixed, citric acid was added, heated and stirred, centrifuged, washed, dried, and calcined to obtain ZnO / Fe2O3 deposited porous alumina nanospheres; the mass ratio of the porous alumina nanospheres, zinc salt, iron salt, and citric acid was 10:2-3:1-2:4-7;

[0012] S3 reduction: ZnO / Fe2O3 deposited porous alumina nanospheres were reduced by hydrogen to obtain Zn / Fe deposited porous alumina nanospheres;

[0013] S4 modification: Zn / Fe deposited porous alumina nanospheres were added to ethanol, a silane coupling agent was added, the reaction was heated with stirring, centrifuged, washed, and dried to obtain modified Zn / Fe deposited porous alumina nanospheres; the mass ratio of the Zn / Fe deposited porous alumina nanospheres and the silane coupling agent was 10:3-5;

[0014] S5 hydrolysis: The modified Zn / Fe deposited porous alumina nanospheres were added to water and stirred for hydrolysis to obtain silica-coated modified Zn / Fe deposited porous alumina nanospheres;

[0015] S6. Graft modification of Teflon: Polytetrafluoroethylene powder was added to Augeo SL-191 solvent and irradiated. Glycidyl methacrylate, a polymerization inhibitor, and a sensitizer were then added. An inert gas was introduced and the mixture was heated with stirring. After completion of the reaction, the mixture was extracted with acetone and dried to obtain a modified Teflon powder. The mass ratio of the polytetrafluoroethylene powder, glycidyl methacrylate, polymerization inhibitor, and sensitizer was 10:2-3:0.01-0.02:0.02-0.05.

[0016] S7. Preparation of a wear-resistant and rust-resistant Teflon coating: Modified Teflon powder and silica-coated modified Zn / Fe deposited porous alumina nanospheres are added to a Teflon primer and stirred to react to prepare a wear-resistant and rust-resistant Teflon coating; the mass ratio of the modified Teflon powder, silica-coated modified Zn / Fe deposited porous alumina nanospheres, and Teflon primer is 10:4-7:70-80.

[0017] As a further improvement of the present invention, the porogen in step S1 is selected from at least one of cetyltrimethylammonium chloride, cetyldimethylbenzylammonium chloride, and cetyltrimethylammonium bromide, the temperature of the heating and stirring reaction is 60-70° C., the time is 30-50 min, the pH value of the solution is adjusted to 9-10, the stirring reaction time is continued for 90-120 min, and the calcination temperature is 600-700° C., and the time is 1-2 h.

[0018] As a further improvement of the present invention, the heating and stirring temperature in step S2 is 85-95°C, the heating and stirring time is 1-3 hours, the calcination temperature is 400-500°C, the calcination time is 1-3 hours, the zinc salt is zinc chloride or zinc nitrate, and the iron salt is at least one of ferric chloride, ferric nitrate, and ferric sulfate.

[0019] As a further improvement of the present invention, the temperature of the hydrogen reduction in step S3 is 1100-1200° C., and the time is 2-4 hours.

[0020] As a further improvement of the present invention, the silane coupling agent in step S4 is at least one of KH550, KH602, and KH792.

[0021] As a further improvement of the present invention, the silane coupling agent is a mixture of KH602 and KH792 in a mass ratio of 2-4:3-5, and the temperature of the heating and stirring reaction is 40-50° C. and the time is 1-2 h.

[0022] As a further improvement of the present invention, the stirring hydrolysis in step S5 is carried out at a temperature of 40-50° C. and for a time of 7-10 h.

[0023] As a further improvement of the present invention, the temperature of the irradiation conditions in step S6 is 100-150°C, the total irradiation dose is 12-15 kGy, the inhibitor is ammonium ferrous sulfate, the sensitizer is concentrated sulfuric acid, the temperature of the heating and stirring reaction is 60-70°C, and the heating and stirring reaction time is 3-5 hours.

[0024] As a further improvement of the present invention, the stirring reaction time in step S7 is 10-12 hours.

[0025] The present invention further protects a wear-resistant and rust-proof Teflon coating, which is prepared by the above-mentioned preparation method of the wear-resistant and rust-proof Teflon coating.

[0026] The present invention has the following beneficial effects:

[0027] The present invention prepares mesoporous alumina nanospheres. The mesoporous structure forms a large specific surface area, promotes the surface deposition of ZnO and Fe2O3, and then is reduced to Zn and Fe through hydrogen. After oxidation, the oxide layer forms a dense oxide layer, which can well protect the substrate from rusting. At the same time, the surface is modified by a silane coupling agent with amino groups, so that not only the surface of the prepared modified Zn / Fe deposited porous alumina nanospheres has amino groups, but also contains a silane structure, and forms a silicon oxide layer under the hydrolysis of water, further improving the wear resistance and mechanical properties of the coating, and also improving the high temperature resistance of the coating.

[0028] The present invention uses electron beam or gamma ray irradiation to break C—C bonds and C—F bonds on a Teflon polytetrafluoroethylene chain to generate free radicals, and utilizes these free radicals to initiate a grafting reaction of glycidyl methacrylate monomer on the surface of the Teflon polytetrafluoroethylene, thereby improving the polarity of the PTFE and further increasing its compatibility and reactivity with other substances. The grafted modified Teflon powder can undergo a ring-opening reaction with silicon oxide-coated modified Zn / Fe deposited porous alumina nanospheres having amino groups on the surface, thereby enabling the silicon oxide-coated modified Zn / Fe deposited porous alumina nanospheres to be very evenly dispersed in the Teflon coating, thereby improving the compatibility of the inorganic particles and greatly improving the mechanical properties, wear resistance, rust resistance, medium resistance and other characteristics of the coating.

[0029] The Augeo SL-191 used in the present invention is a new, environmentally friendly solvent developed by Rhodia that is both hydrophilic and lipophilic. It has a high boiling point, is colorless and odorless, has a low volatilization rate, and is non-toxic to human health and the environment.

[0030] The coating prepared by the present invention has a dense coating after curing and film formation, and has good lubrication conditions and anti-mechanical effect, excellent wear resistance, scratch resistance, medium resistance, high temperature resistance and other properties. It can effectively resist high wear-resistant environments such as sliding friction, impact friction, and cavitation friction. It can not only compensate for the wear defects caused by friction between the two contact surfaces, but also enable the two relatively moving surfaces to have a good lubrication and friction reduction effect, solve the friction and wear problems, and protect the substrate for a long time. DETAILED DESCRIPTION

[0031] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0032] Polytetrafluoroethylene micropowder, with a water content of <0.05%, was purchased from Shenyang Wuliang Technology Co., Ltd.; Teflon primer 420G-703 was purchased from Chemours; and Augeo SL-191 was purchased from Rhodia.

[0033] Example 1

[0034] This embodiment provides a method for preparing a wear-resistant and rust-proof Teflon coating, comprising the following steps:

[0035] Preparation of porous alumina nanospheres: 30 g of aluminum sulfate and 70 g of urea were added to 2 L of water, followed by 1 g of hexadecyldimethylbenzyl ammonium chloride. The mixture was heated to 60°C and stirred for 30 min. The pH of the solution was adjusted to 9 and stirred for 90 min. The mixture was centrifuged, washed, dried, and calcined at 600°C for 1 h to produce porous alumina nanospheres.

[0036] S2. ZnO / Fe2O3 deposition: 10 g of porous alumina nanospheres were added to 200 mL of water, along with 2 g of zinc chloride and 1 g of ferric chloride. The mixture was stirred until uniformly mixed. 4 g of citric acid was added, and the mixture was heated to 85°C, stirred for 1 h, centrifuged, washed, dried, and calcined at 400°C for 1 h to prepare ZnO / Fe2O3-deposited porous alumina nanospheres.

[0037] S3. Reduction: ZnO / Fe2O3 deposited porous alumina nanospheres were heated to 1100°C and reduced in hydrogen for 2 h to obtain Zn / Fe deposited porous alumina nanospheres;

[0038] S4. Modification: 10 g of Zn / Fe-deposited porous alumina nanospheres were added to 200 mL of ethanol, along with 3 g of a silane coupling agent. The mixture was heated to 40°C and stirred for 1 h. The mixture was centrifuged, washed, and dried to obtain modified Zn / Fe-deposited porous alumina nanospheres.

[0039] The silane coupling agent is a mixture of KH602 and KH792 in a mass ratio of 2:3;

[0040] S5. Hydrolysis: 10 g of modified Zn / Fe deposited porous alumina nanospheres were added to 100 mL of water and hydrolyzed at 40°C with stirring for 7 h to obtain silica-coated modified Zn / Fe deposited porous alumina nanospheres;

[0041] S6. Graft modification of Teflon: 10 g of polytetrafluoroethylene powder was added to 200 mL of Augeo SL-191 solvent and irradiated at 100°C for a total dose of 12 kGy. Then, 2 g of glycidyl methacrylate, 0.01 g of ammonium ferrous sulfate, and 0.02 g of concentrated sulfuric acid were added. Nitrogen was introduced and the mixture was heated to 60°C with stirring for 3 h. After the reaction, the mixture was extracted with acetone for 24 h and dried to obtain modified Teflon powder.

[0042] S7. Preparation of wear-resistant and rust-proof Teflon coating: 10 g of modified Teflon powder and 4 g of silica-coated modified Zn / Fe deposited porous alumina nanospheres were added to 70 g of Teflon primer and stirred for 10 h to prepare a wear-resistant and rust-proof Teflon coating.

[0043] Example 2

[0044] This embodiment provides a method for preparing a wear-resistant and rust-proof Teflon coating, comprising the following steps:

[0045] Preparation of porous alumina nanospheres: 50 g of aluminum sulfate and 100 g of urea were added to 2 L of water, followed by 2 g of cetyltrimethylammonium bromide. The mixture was heated to 70°C and stirred for 50 min. The pH of the solution was adjusted to 10 and stirred for 120 min. The mixture was centrifuged, washed, dried, and calcined at 700°C for 2 h to produce porous alumina nanospheres.

[0046] S2. ZnO / Fe2O3 deposition: 10 g of porous alumina nanospheres were added to 200 mL of water, along with 3 g of zinc chloride and 2 g of ferric sulfate. The mixture was stirred until uniformly mixed. 7 g of citric acid was added, and the mixture was heated to 95°C and stirred for 3 h. The mixture was centrifuged, washed, dried, and calcined at 500°C for 3 h to prepare ZnO / Fe2O3-deposited porous alumina nanospheres.

[0047] S3. Reduction: ZnO / Fe2O3 deposited porous alumina nanospheres were heated to 1200°C and reduced in hydrogen for 4 h to obtain Zn / Fe deposited porous alumina nanospheres;

[0048] S4. Modification: 10 g of Zn / Fe-deposited porous alumina nanospheres were added to 200 mL of ethanol, and 5 g of a silane coupling agent was added. The mixture was heated to 50°C and stirred for 2 h. The mixture was centrifuged, washed, and dried to obtain modified Zn / Fe-deposited porous alumina nanospheres.

[0049] The silane coupling agent is a mixture of KH602 and KH792, with a mass ratio of 4:5;

[0050] S5. Hydrolysis: 10 g of modified Zn / Fe deposited porous alumina nanospheres were added to 100 mL of water and hydrolyzed at 50°C with stirring for 10 h to obtain silica-coated modified Zn / Fe deposited porous alumina nanospheres;

[0051] S6. Graft modification of Teflon: 10 g of polytetrafluoroethylene powder was added to 200 mL of Augeo SL-191 solvent and irradiated at 150°C for a total dose of 15 kGy. Then, 3 g of glycidyl methacrylate, 0.02 g of ammonium ferrous sulfate, and 0.05 g of concentrated sulfuric acid were added. Nitrogen was introduced and the mixture was heated to 70°C with stirring for 5 h. After the reaction, the mixture was extracted with acetone for 24 h and dried to obtain modified Teflon powder.

[0052] S7. Preparation of wear-resistant and rust-proof Teflon coating: 10 g of modified Teflon powder and 7 g of silica-coated modified Zn / Fe deposited porous alumina nanospheres were added to 80 g of Teflon primer and stirred for 12 h to prepare a wear-resistant and rust-proof Teflon coating.

[0053] Example 3

[0054] This embodiment provides a method for preparing a wear-resistant and rust-proof Teflon coating, comprising the following steps:

[0055] S1. Preparation of porous alumina nanospheres: 40 g of aluminum sulfate and 80 g of urea were added to 2 L of water, along with 1.5 g of hexadecyltrimethylammonium chloride. The mixture was heated to 65°C and stirred for 40 min. The pH of the solution was adjusted to 9.5 and stirred for 100 min. The mixture was centrifuged, washed, dried, and calcined at 650°C for 1.5 h to produce porous alumina nanospheres.

[0056] S2. ZnO / Fe2O3 deposition: 10 g of porous alumina nanospheres were added to 200 mL of water, along with 2.5 g of zinc nitrate and 1.5 g of ferric nitrate. The mixture was stirred until uniformly mixed. 5.5 g of citric acid was added, and the mixture was heated to 90°C and stirred for 2 h. The mixture was centrifuged, washed, dried, and calcined at 450°C for 2 h to prepare ZnO / Fe2O3-deposited porous alumina nanospheres.

[0057] S3. Reduction: ZnO / Fe2O3-deposited porous alumina nanospheres were heated to 1150°C and reduced in hydrogen for 3 h to obtain Zn / Fe-deposited porous alumina nanospheres.

[0058] S4. Modification: 10 g of Zn / Fe-deposited porous alumina nanospheres were added to 200 mL of ethanol, and 4 g of a silane coupling agent was added. The mixture was heated to 45°C and stirred for 1.5 h. The mixture was centrifuged, washed, and dried to obtain modified Zn / Fe-deposited porous alumina nanospheres.

[0059] The silane coupling agent is a mixture of KH602 and KH792 in a mass ratio of 3:4;

[0060] S5. Hydrolysis: 10 g of modified Zn / Fe deposited porous alumina nanospheres were added to 100 mL of water and hydrolyzed at 45 °C with stirring for 8 h to obtain silica-coated modified Zn / Fe deposited porous alumina nanospheres;

[0061] S6. Graft modification of Teflon: 10 g of polytetrafluoroethylene powder was added to 200 mL of Augeo SL-191 solvent and irradiated at 125°C for a total dose of 13 kGy. Then, 2.5 g of glycidyl methacrylate, 0.015 g of ammonium ferrous sulfate, and 0.04 g of concentrated sulfuric acid were added. Nitrogen was introduced and the mixture was heated to 65°C with stirring for 4 h. After the reaction, the mixture was extracted with acetone for 24 h and dried to obtain modified Teflon powder.

[0062] S7. Preparation of wear-resistant and rust-proof Teflon coating: 10 g of modified Teflon powder and 5 g of silica-coated modified Zn / Fe deposited porous alumina nanospheres were added to 75 g of Teflon primer and stirred for 11 h to prepare a wear-resistant and rust-proof Teflon coating.

[0063] Example 4

[0064] Compared with Example 3, the difference is that the silane coupling agent is a single KH602.

[0065] Example 5

[0066] Compared with Example 3, the difference is that the silane coupling agent is a single KH792.

[0067] Comparative Example 1

[0068] Compared with embodiment 3, the difference is that steps S4 and S5 are not performed.

[0069] The details are as follows:

[0070] S1. Preparation of porous alumina nanospheres: 40 g of aluminum sulfate and 80 g of urea were added to 2 L of water, along with 1.5 g of hexadecyltrimethylammonium chloride. The mixture was heated to 65°C and stirred for 40 min. The pH of the solution was adjusted to 9.5 and stirred for 100 min. The mixture was centrifuged, washed, dried, and calcined at 650°C for 1.5 h to produce porous alumina nanospheres.

[0071] S2. ZnO / Fe2O3 deposition: 10 g of porous alumina nanospheres were added to 200 mL of water, along with 2.5 g of zinc nitrate and 1.5 g of ferric nitrate. The mixture was stirred until uniformly mixed. 5.5 g of citric acid was added, and the mixture was heated to 90°C and stirred for 2 h. The mixture was centrifuged, washed, dried, and calcined at 450°C for 2 h to prepare ZnO / Fe2O3-deposited porous alumina nanospheres.

[0072] S3. Reduction: ZnO / Fe2O3-deposited porous alumina nanospheres were heated to 1150°C and reduced in hydrogen for 3 h to obtain Zn / Fe-deposited porous alumina nanospheres.

[0073] S4. Graft modification of Teflon: 10 g of polytetrafluoroethylene powder was added to 200 mL of Augeo SL-191 solvent and irradiated at 125°C for a total dose of 13 kGy. Then, 2.5 g of glycidyl methacrylate, 0.015 g of ammonium ferrous sulfate, and 0.04 g of concentrated sulfuric acid were added. Nitrogen was introduced and the mixture was heated to 65°C with stirring for 4 h. After the reaction, the mixture was extracted with acetone for 24 h and dried to obtain modified Teflon powder.

[0074] S5. Preparation of wear-resistant and rust-proof Teflon coating: 10 g of modified Teflon powder and 5 g of Zn / Fe-deposited porous alumina nanospheres were added to 75 g of Teflon primer and stirred for 11 h to prepare a wear-resistant and rust-proof Teflon coating.

[0075] Comparative Example 2

[0076] Compared with Example 3, the difference is that zinc nitrate is not added in step S2.

[0077] The details are as follows:

[0078] S2. Fe2O3 deposition: 10 g of porous alumina nanospheres were added to 200 mL of water, followed by 4 g of ferric nitrate. The mixture was stirred and mixed thoroughly. 5.5 g of citric acid was added, and the mixture was heated to 90°C and stirred for 2 h. The mixture was centrifuged, washed, dried, and calcined at 450°C for 2 h to prepare Fe2O3-deposited porous alumina nanospheres.

[0079] Comparative Example 3

[0080] Compared with Example 3, the difference is that no ferric nitrate is added in step S2.

[0081] The details are as follows:

[0082] S2. ZnO deposition: 10 g of porous alumina nanospheres were added to 200 mL of water, followed by 4 g of zinc nitrate. The mixture was stirred and mixed thoroughly. 5.5 g of citric acid was added, and the mixture was heated to 90°C and stirred for 2 h. The mixture was centrifuged, washed, dried, and calcined at 450°C for 2 h to prepare ZnO-deposited porous alumina nanospheres.

[0083] Comparative Example 4

[0084] Compared with Example 3, the difference is that steps S2 and S3 are not performed.

[0085] The details are as follows:

[0086] S1. Preparation of porous alumina nanospheres: 40 g of aluminum sulfate and 80 g of urea were added to 2 L of water, along with 1.5 g of hexadecyltrimethylammonium chloride. The mixture was heated to 65°C and stirred for 40 min. The pH of the solution was adjusted to 9.5 and stirred for 100 min. The mixture was centrifuged, washed, dried, and calcined at 650°C for 1.5 h to produce porous alumina nanospheres.

[0087] S2. Modification: 10 g of porous alumina nanospheres were added to 200 mL of ethanol, 4 g of a silane coupling agent was added, and the mixture was heated to 45°C and stirred for 1.5 h. The mixture was centrifuged, washed, and dried to obtain modified porous alumina nanospheres.

[0088] The silane coupling agent is a mixture of KH602 and KH792 in a mass ratio of 3:4;

[0089] S3. Hydrolysis: 10 g of modified porous alumina nanospheres were added to 100 mL of water and hydrolyzed at 45 ° C with stirring for 8 h to obtain silica-coated modified porous alumina nanospheres;

[0090] S4. Graft modification of Teflon: 10 g of polytetrafluoroethylene powder was added to 200 mL of Augeo SL-191 solvent and irradiated at 125°C for a total dose of 13 kGy. Then, 2.5 g of glycidyl methacrylate, 0.015 g of ammonium ferrous sulfate, and 0.04 g of concentrated sulfuric acid were added. Nitrogen was introduced and the mixture was heated to 65°C with stirring for 4 h. After the reaction, the mixture was extracted with acetone for 24 h and dried to obtain modified Teflon powder.

[0091] S5. Preparation of wear-resistant and rust-proof Teflon coating: 10 g of modified Teflon powder and 5 g of silica-coated modified porous alumina nanospheres were added to 75 g of Teflon primer and stirred for 11 h to prepare a wear-resistant and rust-proof Teflon coating.

[0092] Comparative Example 5

[0093] Compared with Example 3, the difference is that in step S7, the modified Teflon powder is replaced by an equal amount of polytetrafluoroethylene powder.

[0094] The details are as follows:

[0095] S1. Preparation of porous alumina nanospheres: 40 g of aluminum sulfate and 80 g of urea were added to 2 L of water, along with 1.5 g of hexadecyltrimethylammonium chloride. The mixture was heated to 65°C and stirred for 40 min. The pH of the solution was adjusted to 9.5 and stirred for 100 min. The mixture was centrifuged, washed, dried, and calcined at 650°C for 1.5 h to produce porous alumina nanospheres.

[0096] S2. ZnO / Fe2O3 deposition: 10 g of porous alumina nanospheres were added to 200 mL of water, along with 2.5 g of zinc nitrate and 1.5 g of ferric nitrate. The mixture was stirred until uniformly mixed. 5.5 g of citric acid was added, and the mixture was heated to 90°C and stirred for 2 h. The mixture was centrifuged, washed, dried, and calcined at 450°C for 2 h to prepare ZnO / Fe2O3-deposited porous alumina nanospheres.

[0097] S3. Reduction: ZnO / Fe2O3-deposited porous alumina nanospheres were heated to 1150°C and reduced in hydrogen for 3 h to obtain Zn / Fe-deposited porous alumina nanospheres.

[0098] S4. Modification: 10 g of Zn / Fe-deposited porous alumina nanospheres were added to 200 mL of ethanol, and 4 g of a silane coupling agent was added. The mixture was heated to 45°C and stirred for 1.5 h. The mixture was centrifuged, washed, and dried to obtain modified Zn / Fe-deposited porous alumina nanospheres.

[0099] The silane coupling agent is a mixture of KH602 and KH792 in a mass ratio of 3:4;

[0100] S5. Hydrolysis: 10 g of modified Zn / Fe deposited porous alumina nanospheres were added to 100 mL of water and hydrolyzed at 45 °C with stirring for 8 h to obtain silica-coated modified Zn / Fe deposited porous alumina nanospheres;

[0101] S6. Preparation of wear-resistant and rust-resistant Teflon coating: 10 g of polytetrafluoroethylene powder and 5 g of silica-coated modified Zn / Fe-deposited porous alumina nanospheres were added to 75 g of Teflon primer and stirred for 11 h to prepare a wear-resistant and rust-resistant Teflon coating.

[0102] Test Example 1

[0103] The wear-resistant and rust-resistant Teflon coatings prepared in Examples 1-5 and Comparative Examples 1-5 were sprayed onto a primed stainless steel surface to a thickness of approximately 20 μm. The wear resistance was tested on a reciprocating friction and wear tester using a 4.5 mm diameter GCr15 ball as a counter-friction pair, with a load of 8.2 N and a test time of 15 minutes, to measure the wear rate. Scratch resistance was tested in accordance with GB / T 9279. The pencil hardness of the coating was determined in accordance with GB / T 6739-2006. The paint film adhesion was tested in accordance with GB / T 9286-1998. The test piece was cut into 5×5 grids with a blade and adhered with transparent tape. The tape was removed and the paint film integrity was observed. The results are shown in Table 1.

[0104] Table 1

[0105] Group <![CDATA[Wear rate (×10 -4 mm 3 / N·m)]]> Hardness (H) Scratch resistance (kg) Adhesion (grade) Example 1 1.2 4 13 0 Example 2 1.0 4 13 0 Example 3 0.9 4 15 0 Example 4 3.5 3 11 1 Example 5 4.1 3 12 1 Comparative Example 1 12.1 2 9 2 Comparative Example 2 6.4 3 11 1 Comparative Example 3 6.9 3 11 1 Comparative Example 4 8.5 3 10 1 Comparative Example 5 59.8 1 6 3

[0106] It can be seen from the above table that the coatings prepared by the wear-resistant and rust-proof Teflon coatings prepared in Examples 1-3 of the present invention have good wear resistance and comprehensive performance.

[0107] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a wear-resistant and rust-proof Teflon coating, characterized in that: The following steps are involved: S1. Preparation of porous alumina nanospheres: Aluminum sulfate and urea are added to water, a porogen is added, the reaction is heated with stirring, the pH of the solution is adjusted, the reaction is continued with stirring, centrifuged, washed, dried, and calcined to obtain porous alumina nanospheres; the mass ratio of the aluminum sulfate, urea, and porogen is 3-5:7-10:0.1-0.2; S2. ZnO / Fe2O3 deposition: porous alumina nanospheres were added to water, zinc salt and iron salt were added, stirred and mixed, citric acid was added, heated and stirred, centrifuged, washed, dried, and calcined to obtain ZnO / Fe2O3 deposited porous alumina nanospheres; the mass ratio of the porous alumina nanospheres, zinc salt, iron salt, and citric acid was 10:2-3:1-2:4-7; S3 reduction: ZnO / Fe2O3 deposited porous alumina nanospheres were reduced by hydrogen to obtain Zn / Fe deposited porous alumina nanospheres; S4. Modification: Zn / Fe deposited porous alumina nanospheres were added to ethanol, a silane coupling agent was added, the reaction was heated with stirring, centrifuged, washed, and dried to obtain modified Zn / Fe deposited porous alumina nanospheres; the mass ratio of the Zn / Fe deposited porous alumina nanospheres to the silane coupling agent was 10:3-5; the silane coupling agent was a mixture of KH602 and KH792 in a mass ratio of 2-4:3-5; S5 hydrolysis: The modified Zn / Fe deposited porous alumina nanospheres were added to water and stirred for hydrolysis to obtain silica-coated modified Zn / Fe deposited porous alumina nanospheres; S6. Graft modification of Teflon: Polytetrafluoroethylene powder was added to Augeo SL-191 solvent and irradiated. Glycidyl methacrylate, a polymerization inhibitor, and a sensitizer were then added. An inert gas was introduced and the mixture was heated with stirring. After completion of the reaction, the mixture was extracted with acetone and dried to obtain modified Teflon powder. The mass ratio of polytetrafluoroethylene powder, glycidyl methacrylate, polymerization inhibitor, and sensitizer was 10:2-3:0.01-0.02:0.02-0.

05. The polymerization inhibitor was ammonium ferrous sulfate, and the sensitizer was concentrated sulfuric acid. S7. Preparation of a wear-resistant and rust-resistant Teflon coating: Modified Teflon powder and silica-coated modified Zn / Fe deposited porous alumina nanospheres are added to a Teflon primer and stirred to react to prepare a wear-resistant and rust-resistant Teflon coating; the mass ratio of the modified Teflon powder, silica-coated modified Zn / Fe deposited porous alumina nanospheres, and Teflon primer is 10:4-7:70-80.

2. The preparation method according to claim 1, characterized in that In step S1, the porogen is selected from at least one of cetyltrimethylammonium chloride, cetyldimethylbenzylammonium chloride, and cetyltrimethylammonium bromide. The temperature of the heating and stirring reaction is 60-70° C., the time is 30-50 min, the pH value of the solution is adjusted to 9-10, the stirring reaction time is continued for 90-120 min, and the calcination temperature is 600-700° C., and the time is 1-2 h.

3. The preparation method according to claim 1, characterized in that The heating and stirring temperature in step S2 is 85-95° C., the heating and stirring time is 1-3 hours, the calcination temperature is 400-500° C., the calcination time is 1-3 hours, the zinc salt is zinc chloride or zinc nitrate, and the iron salt is at least one of ferric chloride, ferric nitrate, and ferric sulfate.

4. The preparation method according to claim 1, characterized in that The temperature of the hydrogen reduction in step S3 is 1100-1200° C., and the time is 2-4 hours.

5. The preparation method according to claim 1, characterized in that The temperature of the heating and stirring reaction in step S4 is 40-50° C. and the time is 1-2 h.

6. The preparation method according to claim 1, characterized in that The stirring hydrolysis in step S5 is carried out at a temperature of 40-50° C. and for a time of 7-10 h.

7. The preparation method according to claim 1, characterized in that The irradiation temperature in step S6 is 100-150° C., the total irradiation dose is 12-15 kGy, the heating and stirring reaction temperature is 60-70° C., and the heating and stirring reaction time is 3-5 h.

8. The preparation method according to claim 1, characterized in that The stirring reaction time in step S7 is 10-12 hours.

9. A wear-resistant and rust-proof Teflon coating, characterized in that: The wear-resistant and rust-proof Teflon coating is prepared by the preparation method of the wear-resistant and rust-proof Teflon coating according to any one of claims 1 to 8.