Coating for water supply pipeline, water supply pipeline coating and preparation method of water supply pipeline coating

Abstract

The invention relates to the technical field of pipelines, and discloses a paint for a water supply pipeline, a water supply pipeline coating and a preparation method thereof. The coating for the water supply pipeline, provided by the invention, is prepared from the following components in parts by mass: 80 to 100 parts of resin emulsion, 5 to 10 parts of microcapsule repairing agent, 2 to 3 parts of modified graphene oxide, 0.5 to 1.5 parts of defoaming agent, 0.5 to 1.5 parts of flatting agent, 0.5 to 0.8 part of silane coupling agent and 3 to 5 parts of curing agent, the modified graphene oxide is prepared from the following raw materials: graphene oxide, phytic acid, nano diamond powder and 1-butyl-3-methylimidazolium hexafluorophosphate; the microcapsule repairing agent comprises a capsule shell layer and a core material arranged in the capsule shell layer, and the core material comprises tung oil. The paint for the water supply pipeline, the water supply pipeline coating and the preparation method thereof provided by the invention have the characteristics of self-repairing function and corrosion resistance.

Description

Technical Field

[0001] This invention relates to the field of pipeline technology, specifically to a coating for water supply pipelines, a coating material for water supply pipelines, and a method for preparing the same. Background Technology

[0002] In water supply and drainage engineering, pipelines are often buried underground or exposed to humid environments, facing multiple challenges such as water erosion, soil chemical penetration, and microbial corrosion. PE (polyethylene) material, due to its lightweight, pressure resistance, and excellent impact resistance, is widely used in urban water supply systems. However, during long-term service, PE pipes are susceptible to corrosive media penetration, mechanical scratches, and water hammer effects, leading to coating damage, substrate corrosion, and shortened pipe lifespan. Traditional anti-corrosion coatings rely on physical barriers, lacking active repair capabilities and having insufficient chemical corrosion resistance. For example, while traditional coating materials such as epoxy resin and polyurethane can provide some protection, they still have the following technical bottlenecks: First, prolonged contact with chlorinated water or acidic soil can easily cause hydrolysis and swelling of the coating, leading to corrosion of the metal substrate. Water molecules and ions can easily penetrate through the coating's micropores, causing blistering and detachment of the pipe wall. Some solvent-based coatings contain volatile organic compounds, failing to meet green building material standards. Under thermal cycling or mechanical stress, the adhesion between the coating and the pipe decreases, accelerating failure.

[0003] Therefore, there is an urgent need to develop a water supply pipe coating that combines high corrosion resistance, strong impermeability, environmental friendliness, non-toxicity, and long-term stability to overcome the shortcomings of existing technologies. Summary of the Invention

[0004] This invention provides a coating for water supply pipelines, a coating material for water supply pipelines, and a method for preparing the same, which has the characteristics of self-healing and corrosion resistance.

[0005] In a first aspect, the present invention provides a coating for water supply pipes, comprising, by weight, the following components: 80-100 parts resin emulsion, 5-10 parts microcapsule repair agent, 2-3 parts modified graphene oxide, 0.5-1.5 parts defoamer, 0.5-1.5 parts leveling agent, 0.5-0.8 parts silane coupling agent, and 3-5 parts curing agent; The raw materials for the modified graphene oxide include graphene oxide, phytic acid, nanodiamond powder, and 1-butyl-3-methylimidazolium hexafluorophosphate. The microcapsule repair agent includes a capsule shell and a core material disposed within the capsule shell; The core material includes tung oil.

[0006] In one alternative embodiment, the coating for water supply pipes satisfies at least one of the following conditions: (1) The resin emulsion includes epoxy resin emulsion 2060; (2) The resin emulsion has a solid content of 56%-60% by mass; (3) The defoamer includes BYK-019; (4) The leveling agent includes BYK-381; (5) The silane coupling agent includes KH-560; (6) The curing agent includes polyamide curing agent 651; (7) The emulsifier includes OP-10.

[0007] In one optional embodiment, the method for preparing the modified graphene oxide includes the following steps: S1. Add graphene oxide to water and sonicate to obtain dispersion A; S2. Heat dispersion A, add phytic acid solution dropwise to obtain a mixed solution, adjust the pH of the mixed solution to 9-10, stir the reaction, and perform the first freeze-drying to obtain powder B; S3. Disperse nanodiamond powder and 1-butyl-3-methylimidazolium hexafluorophosphate in water by ultrasonication, add powder B, stir ultrasonically, wash with water, and then perform a second freeze-drying to obtain the modified graphene oxide.

[0008] In one optional embodiment, the mass ratio of graphene oxide to water in S1 is (10-20):200; Optionally, the water includes deionized water; And / or, the mass ratio of graphene oxide to phytic acid solution in S2 is 1:(3-5); And / or, the mass ratio of nanodiamond powder, 1-butyl-3-methylimidazolium hexafluorophosphate and powder B in S3 is (5-7):(1-2):(10-20).

[0009] In one alternative embodiment, the coating for water supply pipes satisfies at least one of the following conditions: (1) The ultrasonic treatment time in S1 is 1-3 hours and the ultrasonic power is 300-400W; (2) The heating temperature in S2 is 50-70℃; (3) The molar concentration of the phytic acid solution in S2 is 0.4-0.6 mol / L; (4) In S2, the pH is adjusted using ammonia water, and the molar concentration of ammonia water is 0.5-1.5 mol / L; (5) The stirring reaction time in S2 is 10-14h, and the stirring speed is 300-500rpm; (6) The temperatures of the first freeze-drying and the second freeze-drying are independently -55~-45℃, and the times of the first freeze-drying and the second freeze-drying are independently 12-24h; (7) The ultrasonic stirring time in S3 is 1-2 hours; (8) The mass ratio of nanodiamond powder to water in S3 is (5-7):100.

[0010] In one optional embodiment, the preparation method of the microcapsule repair agent includes the following steps: Emulsifier and tung oil were added to water and stirred to emulsify. Sodium alginate solution was added and stirred. Then, calcium chloride solution was added dropwise to react. After the reaction, the solid and liquid were separated. The solid was washed with water and then freeze-dried to obtain the microcapsule repair agent.

[0011] In one alternative embodiment, the coating for water supply pipes satisfies at least one of the following conditions: (1) The mass ratio of the tung oil to the sodium alginate solution is (3-5):(15-20); (2) The mass fraction of sodium alginate in the sodium alginate solution is 1.5-2.5%; (3) The mass fraction of calcium chloride in the calcium chloride solution is 3-5%; (4) The stirring speed for emulsification is 8000-12000 rpm, and the emulsification time is 5-15 min; (5) The stirring speed is 6000-8000 rpm and the stirring time is 5-10 min; (6) The rate of adding calcium chloride solution is 1-2 mL / min; (7) The temperature of the third freeze-drying is -55~-45℃, and the freeze-drying time is 12-16h; (8) In the steps of adding emulsifier and tung oil to water, stirring to emulsify, adding sodium alginate solution, stirring and treating, and then adding calcium chloride solution dropwise to react, the mass ratio of the emulsifier, water and calcium chloride solution is (0.5-0.8):100:(8-10). Optionally, the water includes deionized water; (9) The emulsifier includes OP-10; (10) In the steps of adding emulsifier and tung oil to water, stirring to emulsify, adding sodium alginate solution, stirring and treating, and then adding calcium chloride solution dropwise to react, the reaction temperature is 25-30℃ and the reaction time is 0.4-0.6h.

[0012] Secondly, the present invention provides a method for preparing the coating for water supply pipelines, comprising the following steps: mixing the raw materials according to the formula ratio to obtain the coating; Optionally, the preparation method includes: adding resin emulsion to a material tank according to the formula ratio, stirring for the first time, adding modified graphene oxide and silane coupling agent, stirring for the second time while maintaining the rotation speed, adding microcapsule repair agent, stirring for the third time, adding defoamer and leveling agent in sequence, stirring for the fourth time while maintaining the rotation speed, and finally adding curing agent, stirring for the fifth time while maintaining the rotation speed to obtain the coating.

[0013] In one optional embodiment, the first stirring speed is 500-800 rpm, and the stirring time is 9-11 min; And / or, the second stirring time is 14-16 min; And / or, the third stirring is performed at a speed of 300-500 rpm for a stirring time of 9-11 min; And / or, the fourth and fifth stirring times are 4-6 minutes.

[0014] Thirdly, the present invention provides a coating for water supply pipes, wherein the raw material is the coating described above or a coating prepared according to the preparation method described above.

[0015] Fourthly, the present invention provides a method for preparing the coating on the water supply pipe, wherein the coating is sprayed onto the pipe to form a wet film, and then cured to obtain the coating. Optionally, the spraying pressure is 0.3-0.5 MPa, and the spray gun distance is 20-30 cm; Optionally, the thickness of the wet film is 80-120 μm; Optionally, the curing temperature is 24-26℃ and the curing time is 6-8 days.

[0016] The technical solution of this invention has the following advantages: 1. The present invention provides a coating for water supply pipelines, comprising, by weight, the following components: 80-100 parts resin emulsion, 5-10 parts microcapsule repair agent, 2-3 parts modified graphene oxide, 0.5-1.5 parts defoamer, 0.5-1.5 parts leveling agent, 0.5-0.8 parts silane coupling agent, and 3-5 parts curing agent; the modified graphene oxide raw materials include graphene oxide, phytic acid, nano-diamond powder, and 1-butyl-3-methylimidazolium hexafluorophosphate; the microcapsule repair agent includes a capsule shell and a core material disposed within the capsule shell; the core material includes tung oil.

[0017] The dense structure and chemical inertness of graphene oxide form a physical barrier, preventing corrosive media from contacting the pipe substrate. The phosphate groups in phytic acid undergo esterification with the hydroxyl and epoxy groups on the graphene oxide surface, forming covalent bonds and enhancing the activity of the graphene oxide. The phosphate groups can also form a passivation film on the metal surface, further inhibiting electrochemical corrosion. Furthermore, phytic acid has antibacterial properties, inhibiting the adhesion and growth of microorganisms on the coating surface.

[0018] The layered structure of modified graphene oxide extends the diffusion path of corrosive media, forming a physical barrier. The high hardness and chemical inertness of nanodiamond powder fill the micropores in the coating, reducing defects. Together, they form a complex barrier network that effectively blocks the penetration of corrosive media such as water and oxygen, improving the coating's density and corrosion resistance. Nanodiamond powder fills the spaces between graphene oxide layers, forming a "brick-and-mortar" structure, significantly improving the coating's hardness and wear resistance. Simultaneously, the high thermal conductivity of nanodiamond accelerates heat transfer during the coating curing process, reducing internal stress.

[0019] 1-Butyl-3-methylimidazolium hexafluorophosphate is adsorbed onto the surface of graphene oxide via π-π interactions, reducing its surface energy and improving its compatibility with the resin. The presence of ionic liquids reduces the aggregation of microcapsule repair agents in the coating, promoting their uniform dispersion.

[0020] The water supply pipe coating provided by this invention has a self-healing function. Modified graphene oxide and microcapsule repair agent significantly improve the overall performance of the self-healing coating through multi-scale synergistic effects. The sheet structure of modified graphene oxide constructs a dense physical barrier in the coating, effectively extending the diffusion path of corrosive media such as water, oxygen, and chloride ions; while the conjugated double bonds of the tung oil core material in the microcapsules form a tough polymer film through self-oxidation reaction, which can quickly solidify and fill defects when the coating is damaged. First, the partially reduced oxygen-containing functional groups on the surface of modified graphene oxide construct a conductive network, significantly reducing the activation energy of tung oil oxidation and solidification, thus improving the repair speed; second, the chemical adsorption effect generated by phosphorus doping and the physical barrier of tung oil molecules form a dual protection, forming a dense protective film on the metal surface; when microcracks occur, the rigid sheets of graphene oxide cause the microcapsules to rupture directionally through stress transmission, and in the process of filling the healing area, it forms an interpenetrating network structure with the solidified tung oil, simultaneously improving the mechanical strength and barrier performance of the repaired area. Detailed Implementation

[0021] The following embodiments are provided to better understand the present invention, but the following embodiments do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the scope of protection of the present invention.

[0022] Unless otherwise specified, all experimental steps or conditions in the examples were performed according to conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0023] Raw material source: Epoxy resin emulsion 2060: Bass Synthetic New Materials (Shenzhen) Co., Ltd., solid content 58%; Silane coupling agent KH-560: Shanghai Yihe Biotechnology Co., Ltd.; Polyamide curing agent 651: Guangzhou Nalong Chemical Co., Ltd.; Defoamer BYK-019: BYK Additives (Shanghai) Co., Ltd.; Leveling agent BYK-381: BYK Additives (Shanghai) Co., Ltd.

[0024] Example 1 This embodiment provides a corrosion-resistant water supply pipe coating with self-healing function. The water supply pipe coating formula 1 is as follows: by weight, 90 parts epoxy resin emulsion (epoxy resin emulsion 2060), 8 parts microcapsule repair agent, 2.5 parts modified graphene oxide, 1 part defoamer (BYK-019), 1 part leveling agent (BYK-381), 0.6 parts silane coupling agent (KH-560), and 4 parts curing agent (polyamide curing agent 651).

[0025] The modified graphene oxide is prepared as follows: S1. Add 15 parts by mass of graphene oxide to 200 parts by mass of deionized water and sonicate for 2 h at a power of 350W to obtain dispersion A; S2. Dispersion A was heated to 60℃, and phytic acid solution with a concentration of 0.5 mol / L was added dropwise while maintaining the temperature to obtain a mixed solution in which the mass ratio of graphene oxide to phytic acid solution was 1:4. Then, the pH was adjusted to 9.5 with 1 mol / L ammonia water, and stirred for 12 h under a nitrogen atmosphere at a stirring speed of 450 rpm. Then, it was freeze-dried at -50℃ for 20 h to obtain powder B. S3. Six parts by mass of nano-diamond powder and 1.5 parts by mass of 1-butyl-3-methylimidazolium hexafluorophosphate were ultrasonically dispersed in 100 parts by mass of deionized water, 15 parts by mass of powder B were added, and the mixture was ultrasonically stirred for 1.5 h. The mixture was then washed with deionized water and freeze-dried at -50℃ for 20 h to obtain the modified graphene oxide.

[0026] The preparation method of the microcapsule repair agent is as follows: 0.6 parts by mass of emulsifier OP-10 and 4 parts by mass of tung oil are added to 100 parts by mass of deionized water and emulsified at 10,000 rpm for 10 min. Then, 18 parts by mass of sodium alginate solution with a mass fraction of 2% are added and stirred at 7,000 rpm for 8 min. Finally, 9 parts by mass of calcium chloride solution with a mass fraction of 4% are added at a dropping rate of 1.5 mL / min. The mixture is reacted at 25°C for 0.5 h, and then filtered to obtain a solid. The solid is washed with deionized water and then freeze-dried at -50°C for 14 h to obtain the microcapsule repair agent.

[0027] This embodiment provides a method for preparing a coating for water supply pipes. The specific steps of the preparation method are as follows: According to Formula 1, epoxy resin emulsion is added to the mixing tank and stirred at 700 rpm for 10 min. Modified graphene oxide and silane coupling agent are added, and stirring is maintained at the same speed for 15 min. Microcapsule repair agent is then added, and the speed is adjusted to 400 rpm and stirred for 10 min. Defoamer and leveling agent are added in sequence, and stirring is continued for 5 min. Finally, curing agent is added and stirred for 5 min to obtain the coating. The coating is sprayed onto the pipeline at a pressure of 0.4 MPa and a spray gun distance of 25 cm, controlling the wet film thickness to 100 μm. It is then cured at 25℃ for 7 days to obtain the corrosion-resistant water supply pipeline coating.

[0028] Example 2 This embodiment provides a water supply pipe coating. The water supply pipe coating formula 2 is as follows: by weight, 80 parts epoxy resin emulsion (epoxy resin emulsion 2060), 5 parts microcapsule repair agent, 2 parts modified graphene oxide, 0.5 parts defoamer (BYK-019), 0.5 parts leveling agent (BYK-381), 0.5 parts silane coupling agent (KH-560), and 3 parts curing agent (polyamide curing agent 651).

[0029] The modified graphene oxide is prepared as follows: S1. Add 10 parts by mass of graphene oxide to 200 parts by mass of deionized water, and sonicate for 2 h at a power of 300W to obtain dispersion A; S2. Dispersion A was heated to 60℃, and phytic acid solution with a concentration of 0.5 mol / L was added dropwise while maintaining the temperature to obtain a mixed solution in which the mass ratio of graphene oxide to phytic acid solution was 1:3. Then, the pH was adjusted to 9 with 1 mol / L ammonia water, and the mixture was stirred for 10 h under a nitrogen atmosphere at a stirring speed of 300 rpm. Then, it was freeze-dried at -50℃ for 12 h to obtain powder B. S3. Five parts by mass of nano-diamond powder and one part by mass of 1-butyl-3-methylimidazolium hexafluorophosphate were ultrasonically dispersed in 100 parts by mass of deionized water. Ten parts by mass of powder B were added, and the mixture was ultrasonically stirred for 1 h. The mixture was then washed with deionized water and freeze-dried at -50°C for 12 h to obtain the modified graphene oxide.

[0030] The preparation method of the microcapsule repair agent is as follows: 0.5 parts by weight of emulsifier OP-10 and 3 parts by weight of tung oil are added to 100 parts by weight of deionized water and emulsified at 8000 rpm for 5 min. Then, 15 parts by weight of sodium alginate solution with a mass fraction of 1.5% are added and stirred at 6000 rpm for 5 min. Then, 8 parts by weight of calcium chloride solution with a mass fraction of 3% are added at a dropping rate of 1 mL / min. The reaction is carried out at 25°C for 0.5 h. The solid is then filtered to obtain a solid. The solid is washed with deionized water and then freeze-dried at -50°C for 12 h to obtain the microcapsule repair agent.

[0031] This embodiment provides a method for preparing a coating for water supply pipes. The specific steps of the preparation method are as follows: According to Formula 2, epoxy resin emulsion is added to the mixing tank and stirred at 500 rpm for 10 min. Modified graphene oxide and silane coupling agent are added, and stirring is maintained at the same speed for 15 min. Microcapsule repair agent is then added, and the speed is adjusted to 300 rpm and stirred for 10 min. Defoamer and leveling agent are added in sequence, and stirring is continued for 5 min. Finally, curing agent is added and stirred for 5 min to obtain the coating. The coating is sprayed onto the pipeline at a pressure of 0.3 MPa and a spray gun distance of 20 cm, controlling the wet film thickness to 80 μm. It is then cured at 25℃ for 7 days to obtain the corrosion-resistant water supply pipeline coating.

[0032] Example 3 This embodiment provides a water supply pipe coating. The water supply pipe coating formula 3 is as follows: by weight, 100 parts epoxy resin emulsion (epoxy resin emulsion 2060), 10 parts microcapsule repair agent, 3 parts modified graphene oxide, 1.5 parts defoamer (BYK-019), 1.5 parts leveling agent (BYK-381), 0.8 parts silane coupling agent (KH-560), and 5 parts curing agent (polyamide curing agent 651).

[0033] The modified graphene oxide is prepared as follows: S1. Add 20 parts by mass of graphene oxide to 200 parts by mass of deionized water, and sonicate for 2 h at a power of 400W to obtain dispersion A; S2. Dispersion A was heated to 60℃, and phytic acid solution with a concentration of 0.5 mol / L was added dropwise while maintaining the temperature to obtain a mixed solution in which the mass ratio of graphene oxide to phytic acid solution was 1:5. Then, the pH was adjusted to 10 with 1 mol / L ammonia water, and the mixture was stirred for 14 h under a nitrogen atmosphere at a stirring speed of 500 rpm. Then, it was freeze-dried at -50℃ for 24 h to obtain powder B. S3. Seven parts by weight of nanodiamond powder and two parts by weight of 1-butyl-3-methylimidazolium hexafluorophosphate were ultrasonically dispersed in 100 parts by weight of deionized water. 20 parts by weight of powder B were added, and the mixture was ultrasonically stirred for 2 h. The mixture was then washed with deionized water and freeze-dried at -50 ℃ for 24 h to obtain the modified graphene oxide.

[0034] The preparation method of the microcapsule repair agent is as follows: 0.8 parts by weight of emulsifier OP-10 and 5 parts by weight of tung oil are added to 100 parts by weight of deionized water and emulsified at 12000 rpm for 15 min. Then, 20 parts by weight of sodium alginate solution with a mass fraction of 2.5% are added and stirred at 8000 rpm for 10 min. Then, 10 parts by weight of calcium chloride solution with a mass fraction of 5% are added at a dropping rate of 2 mL / min. The reaction is carried out at 25°C for 0.5 h. The solid is then filtered to obtain a solid. The solid is washed with deionized water and then freeze-dried at -50°C for 16 h to obtain the microcapsule repair agent.

[0035] This embodiment provides a method for preparing a coating for water supply pipes. The specific steps of the preparation method are as follows: According to formula 3, epoxy resin emulsion is added to the mixing tank and stirred at 800 rpm for 10 min. Modified graphene oxide and silane coupling agent are added, and stirring is maintained at the same speed for 15 min. Then, microcapsule repair agent is added, the speed is adjusted to 500 rpm and stirred for 10 min. Defoamer and leveling agent are added in sequence, and stirring is continued for 5 min. Finally, curing agent is added and stirred for 5 min to obtain the coating. The coating is sprayed onto the pipeline at a pressure of 0.5 MPa and a spray gun distance of 30 cm, controlling the wet film thickness to 120 μm. It is then cured at 25℃ for 7 days to obtain the corrosion-resistant water supply pipeline coating.

[0036] Comparative Example 1 Without adding the microcapsule repair agent, the remaining steps are the same as in Example 1.

[0037] Comparative Example 2 Without adding modified graphene oxide, the remaining steps are the same as in Example 1.

[0038] Comparative Example 3 No modification was made to the graphene oxide; the remaining steps were the same as in Example 1.

[0039] Comparative Example 4 The preparation of modified graphene oxide does not involve the addition of nanodiamond powder, and the remaining steps are the same as in Example 1.

[0040] Comparative Example 5 Phytic acid solution was not added during the preparation of modified graphene oxide, and the remaining steps were the same as in Example 1.

[0041] Test Example 1 Self-repair performance test A 0.2 mm wide and 50 μm deep scratch was made on the coated surface using a blade. The scratch healing rate was tested for 72 h at 25°C and 50% RH. Healing rate (%) = (initial scratch area - residual scratch area) / initial scratch area × 100%.

[0042] Corrosion resistance test The corrosion resistance of the coatings prepared in the examples and comparative examples was determined in accordance with GB / T 1771-2007.

[0043] The experimental results are summarized in the table below: Table 1

[0044] By comparing the test data of Examples 1-3 and Comparative Examples 1-5 in Table 1, it can be seen that the coating prepared by the present invention has self-healing function and excellent corrosion resistance.

[0045] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A coating for water supply pipes, characterized in that, By weight, it includes the following components: 80-100 parts resin emulsion, 5-10 parts microcapsule repair agent, 2-3 parts modified graphene oxide, 0.5-1.5 parts defoamer, 0.5-1.5 parts leveling agent, 0.5-0.8 parts silane coupling agent, and 3-5 parts curing agent. The raw materials for the modified graphene oxide include graphene oxide, phytic acid, nanodiamond powder, and 1-butyl-3-methylimidazolium hexafluorophosphate. The microcapsule repair agent includes a capsule shell and a core material disposed within the capsule shell; The core material includes tung oil.

2. The coating for water supply pipelines according to claim 1, characterized in that, The preparation method of the modified graphene oxide includes the following steps: S1. Add graphene oxide to water and sonicate to obtain dispersion A; S2. Heat dispersion A, add phytic acid solution dropwise to obtain a mixed solution, adjust the pH of the mixed solution to 9-10, stir the reaction, and perform the first freeze-drying to obtain powder B; S3. Disperse nanodiamond powder and 1-butyl-3-methylimidazolium hexafluorophosphate in water by ultrasonication, add powder B, stir ultrasonically, wash with water, and then perform a second freeze-drying to obtain the modified graphene oxide.

3. The coating for water supply pipelines according to claim 2, characterized in that, The mass ratio of graphene oxide to water in S1 is (10-20):200; And / or, the mass ratio of graphene oxide to phytic acid solution in S2 is 1:(3-5); And / or, the mass ratio of nanodiamond powder, 1-butyl-3-methylimidazolium hexafluorophosphate and powder B in S3 is (5-7):(1-2):(10-20).

4. The coating for water supply pipes according to claim 2 or 3, characterized in that, At least one of the following conditions must be met: (1) The ultrasonic treatment time in S1 is 1-3 hours and the ultrasonic power is 300-400W; (2) The heating temperature in S2 is 50-70℃; (3) The molar concentration of the phytic acid solution in S2 is 0.4-0.6 mol / L; (4) In S2, the pH is adjusted using ammonia water, and the molar concentration of ammonia water is 0.5-1.5 mol / L; (5) The stirring reaction time in S2 is 10-14h, and the stirring speed is 300-500rpm; (6) The temperatures of the first freeze-drying and the second freeze-drying are independently -55~-45℃, and the times of the first freeze-drying and the second freeze-drying are independently 12-24h; (7) The ultrasonic stirring time in S3 is 1-2 hours; (8) The mass ratio of nanodiamond powder to water in S3 is (5-7):

100.

5. The coating for water supply pipes according to claim 1, characterized in that, The preparation method of the microcapsule repair agent includes the following steps: Emulsifier and tung oil were added to water and stirred to emulsify. Sodium alginate solution was added and stirred. Then calcium chloride solution was added dropwise. After the reaction, the solid and liquid were separated. The solid was washed with water and then freeze-dried to obtain the microcapsule repair agent.

6. The coating for water supply pipelines according to claim 5, characterized in that, At least one of the following conditions must be met: (1) The mass ratio of the tung oil to the sodium alginate solution is (3-5):(15-20); (2) The mass fraction of sodium alginate in the sodium alginate solution is 1.5-2.5%; (3) The mass fraction of calcium chloride in the calcium chloride solution is 3-5%; (4) The stirring speed for emulsification is 8000-12000 rpm, and the emulsification time is 5-15 min; (5) The stirring speed is 6000-8000 rpm and the stirring time is 5-10 min; (6) The rate of adding calcium chloride solution is 1-2 mL / min; (7) The temperature of the third freeze-drying is -55~-45℃, and the freeze-drying time is 12-16h; (8) In the steps of adding emulsifier and tung oil to water, stirring to emulsify, adding sodium alginate solution, stirring and treating, and then adding calcium chloride solution dropwise, the mass ratio of the emulsifier, water and calcium chloride solution is (0.5-0.8):100:(8-10). (9) The emulsifier includes OP-10; (10) The reaction temperature is 25-30℃ and the reaction time is 0.4-0.6h.

7. A method for preparing a coating for water supply pipelines according to any one of claims 1-6, characterized in that, The process includes the following steps: mixing the raw materials according to the formula ratio to obtain the coating; Optionally, the preparation method includes: adding resin emulsion to a material tank according to the formula ratio, stirring for the first time, adding modified graphene oxide and silane coupling agent, stirring for the second time while maintaining the rotation speed, adding microcapsule repair agent, stirring for the third time, adding defoamer and leveling agent in sequence, stirring for the fourth time while maintaining the rotation speed, and finally adding curing agent, stirring for the fifth time while maintaining the rotation speed to obtain the coating.

8. The method for preparing the coating for water supply pipelines according to claim 7, characterized in that, The first stirring motion is performed at a speed of 500-800 rpm for 9-11 minutes. And / or, the second stirring time is 14-16 min; And / or, the third stirring is performed at a speed of 300-500 rpm for a time of 9-11 minutes; And / or, the fourth and fifth stirring times are 4-6 minutes.

9. A coating for water supply pipes, characterized in that, The raw materials are the coatings described in any one of claims 1-6 or the coatings prepared according to the preparation method of any one of claims 7-8.

10. A method for preparing the coating for a water supply pipeline as described in claim 9, characterized in that, The coating is sprayed onto the pipe to form a wet film, and then cured. Optionally, the spraying pressure is 0.3-0.5 MPa, and the spray gun distance is 20-30 cm; Optionally, the thickness of the wet film is 80-120 μm; Optionally, the curing temperature is 24-26℃ and the curing time is 6-8 days.

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