Anti-blocking composite coating material for drip irrigation tape irrigation emitter and preparation and spraying process of anti-blocking composite coating material

Abstract

The invention relates to the technical field of production of drip irrigation tape emitters, in particular to an anti-blocking composite coating material for a drip irrigation tape emitter and a preparation and spraying process of the anti-blocking composite coating material. The invention provides an anti-blocking composite coating material for a drip irrigation emitter of a drip irrigation tape. The anti-blocking composite coating material comprises a base coating, an interlayer coating and an adjacent surface coating. The coating method of the anti-blocking composite coating material comprises the steps that S1, surface pretreatment is conducted, specifically, the surface is subjected to ultrasonic cleaning through ethyl alcohol, and plasma treatment activation is conducted; s2, substrate coating coating: spraying and curing a substrate coating, and bridging by a silane coupling agent; s3, interlayer coating coating: spraying an interlayer coating grafting monomer, and performing ultraviolet curing enhancement; s4, coating of an adjacent surface coating: spraying the PTFE adjacent surface coating, and performing high-temperature curing to combine with nano-silver; and S5, post-treatment: vapor deposition of a hydrophobic membrane is carried out, and ultraviolet crosslinking is carried out to improve durability. Through the design of the composite coating, microbial attachment, chemical deposition and particle retention are synchronously inhibited, and compared with the overall material modification of the irrigation emitter or the machining of a mold with a complex structure, the treatment cost is relatively low.

Description

Technical Field

[0001] The invention relates to the technical field of production of drip irrigation tape emitters, and in particular to an anti-clogging composite coating material for a drip irrigation tape emitter and a preparation and spraying process thereof. Background Art

[0002] As the core means of modern efficient water-saving irrigation, irrigation technology plays an important role in global agriculture. It can reduce water waste by 30%-50% and increase crop yield by 15%-30% by precisely controlling the delivery of water and fertilizer. As the key carrier of the drip irrigation system, the performance of the drip irrigation belt directly determines the irrigation efficiency, and the emitter is the core functional unit of the drip irrigation belt, which is responsible for converting high-pressure water flow into stable drip flow through the internal flow channel to achieve uniform irrigation.

[0003] At present, the flow channel of the sprinkler usually adopts a labyrinth or tooth-shaped structure to achieve pressure reduction by extending the water flow path and increasing the turbulence intensity. However, the narrow flow channel and high aspect ratio lead to the following blockage problems: ① Biological blockage: microorganisms (such as Pseudomonas, algae) form biofilms on the surface of the flow channel, resulting in a decrease in the cross-sectional area of ​​the flow channel; ② Chemical blockage: Ca in the water 2+ Mg 2+ Plasma and CO3 2-Combined to form carbonate precipitation, or silicate crystal deposition; ③ Physical blockage: suspended particles are retained in the flow channel. According to statistics, the efficiency loss of drip irrigation systems due to blockage is as high as 40%, which seriously restricts its promotion and application. In order to deal with the problem of emitter blockage, the existing technology mainly starts from two aspects: material modification and structural optimization. For example: CN202411454419.4 invention discloses an anti-blocking emitter based on a crescent-shaped dune structure, including an anti-blocking maze flow channel based on a crescent-shaped dune structure arranged on an emitter patch; the maze flow channel is composed of a number of flow channel units connected in series in sequence; the flow channel unit is an axisymmetric structure, including a heart-shaped side structure, a crescent-shaped dune center fractal structure, an inlet direct current section and an outlet direct current section ; The heart-shaped side structure and the fractal structure in the crescent-shaped dune form a symmetrical two-way diversion channel; The fractal structure in the crescent-shaped dune is composed of a gentle slope facing the water, a crescent end face and a steep slope facing the water, the gentle slope facing the water is convex, the steep slope facing the water is concave, and the gentle slope facing the water and the steep slope facing the water are connected at the top to form a crescent end face; The sprinkler of the present invention can make particles flow out of the sprinkler with the water flow while consuming the water flow energy in moderation, and the particles are not easy to deposit and accumulate inside the sprinkler flow channel, and have high anti-blocking performance under the premise of ensuring hydraulic performance. CN03108048.0 The invention discloses a preparation process of antibacterial materials for micro-irrigation sprinklers, which can be made and formed on the sprinkler production line by infiltrating antibacterial materials into low-pressure high-density polyethylene plastics, and adding dispersants, coupling agents and additives. This antibacterial material is an organic-inorganic composite antibacterial material, and its main antibacterial components are pyridinium salts, chlorophenols, quaternary ammonium salts, biguanide compounds, ethanol, quaternary ammonium salts and silver organic complex ions. Due to the use of organic-inorganic composite antibacterial materials, the amount of silver can be reduced, which greatly reduces the cost; and the organic-inorganic antibacterial components, Ag~(+) and various organic antibacterial components can be slowly released, and the antibacterial components lost on the surface of the material are continuously replenished through migration, so as to destroy the cell membrane and respiratory system of microorganisms, denature proteins and cell walls, acidify -SH, and hinder metabolism as the main bactericidal mechanism. However, the existing technology has the following defects: ① Single functionality: material modification only improves surface smoothness or temporary antibacterial properties, and structural optimization only alleviates physical blockage, and cannot comprehensively deal with the three types of biological, chemical, and physical blockages; ② Insufficient durability: The functional components of the modified materials (such as antibacterial agents) are easy to lose, and the structurally optimized flow channels will still fail due to chemical deposition and biofilm accumulation during long-term use; ③ High process cost: Complex flow channel structures require precision mold processing, which leads to a significant increase in production costs and is difficult to apply on a large scale; in addition, material modification is currently unable to achieve local modification, and the entire emitter needs to be modified, which greatly increases the cost of raw materials. Summary of the invention

[0004] (I) In view of the defects of the prior art, the present invention proposes a drip irrigation tape emitter anti-clogging composite coating material and a preparation and spraying process, aiming to solve the following core problems:

[0005] ① Insufficient comprehensive protection: Through the multifunctional design of the composite coating, microbial attachment, chemical deposition and particle retention are simultaneously inhibited;

[0006] ② Weak interface bonding: Use interface modification technology to improve the adhesion between the coating and the polyethylene substrate;

[0007] ③ Poor long-term durability: Through nanomaterial enhancement and curing process optimization, the coating can maintain stable performance under long-term water erosion and chemical corrosion;

[0008] ④ Low process economy: The composite coating is thin, and the processing cost is low compared to the overall material modification of the sprinkler or complex mold processing.

[0009] (II) Technical solution

[0010] A composite coating material for preventing clogging of a drip irrigation tape emitter comprises a base coating 1, an intermediate coating 2 and a surface coating 3; the base coating 1 is composed of epoxy resin, silane coupling agent, curing agent and solvent, and is used to enhance the adhesion between the coating and the substrate; the intermediate coating 2 is composed of polyurethane, nano-silicon dioxide, dispersant and solvent, and is used to provide wear resistance and corrosion resistance; the surface coating 3 is composed of polytetrafluoroethylene emulsion, nano-silver particles, graphene oxide, silane coupling agent and deionized water, and is used to provide hydrophobicity and antibacterial properties.

[0011] Preferably, the weight percentages of the components of the base coating 1 are as follows: epoxy resin accounts for 60%, silane coupling agent accounts for 5%, curing agent accounts for 10%, and solvent accounts for 25%.

[0012] Preferably, the weight percentages of the components of the sandwich coating 2 are as follows: polyurethane accounts for 70%; nano-silicon dioxide accounts for 5%; dispersant accounts for 2%; and solvent accounts for 23%.

[0013] Preferably, the weight percentages of the three components of the surface coating are as follows: polytetrafluoroethylene emulsion accounts for 50%; nano silver particles account for 2%; graphene oxide accounts for 1%; silane coupling agent accounts for 3%; and deionized water accounts for 44%.

[0014] A method for preparing a drip irrigation tape emitter anti-clogging composite coating material, using the above-mentioned drip irrigation tape emitter anti-clogging composite coating material, the method for preparing the anti-clogging composite coating material comprises the following steps:

[0015] S1: Preparation of base coating 1: Accurately weigh epoxy resin, silane coupling agent, curing agent and solvent, and filter to ensure that the raw materials are free of impurities; add epoxy resin and silane coupling agent into a stirring container, and stir at a speed of 500-800rpm for 10 minutes; slowly add curing agent and continue stirring for 15 minutes to ensure uniform mixing; add solvent acetone and adjust the viscosity to 200-300mPa·s; filter the mixture with a 200-mesh filter to remove undissolved particles or impurities; store the mixture in a sealed container to avoid contact with moisture and dust;

[0016] S2: Preparation of sandwich coating 2: Accurately weigh polyurethane, nano-silica, dispersant and solvent; ensure that nano-silica is dry and free of moisture; add nano-silica and dispersant to a small amount of solvent, and use a high-speed disperser to pre-disperse for 10 minutes at a speed of 2000-3000rpm; add the pre-dispersed nano-silica to polyurethane and stir at a speed of 800-1000rpm for 20 minutes; slowly add the remaining solvent and adjust the viscosity to 300-400mPa·s; grind the mixture with a three-roll mill to ensure that the nano-silica is evenly dispersed and the particle size is ≤100nm; filter the mixture with a 300-mesh filter to remove agglomerated particles; store the mixture in a sealed container to avoid contact with moisture and high temperature;

[0017] S3: Preparation of surface coating 3: Accurately weigh polytetrafluoroethylene emulsion, nanosilver particles, graphene oxide, silane coupling agent and deionized water; ensure that the nanosilver particles and graphene oxide are evenly dispersed; add the nanosilver particles and graphene oxide to a small amount of deionized water and disperse them using an ultrasonic disperser for 30 minutes; add the pre-dispersed nanosilver and graphene oxide to the polytetrafluoroethylene emulsion and stir at a speed of 500-800rpm for 15 minutes; add the silane coupling agent and continue stirring for 10 minutes; add the remaining deionized water and adjust the viscosity to 100-200mPa·s; filter the mixture using a 200-mesh filter to remove undispersed particles; store the mixture in a sealed container to avoid light and high temperature.

[0018] A coating method of a drip irrigation tape emitter anti-clogging composite coating material uses the above-mentioned drip irrigation tape emitter anti-clogging composite coating material, and the coating method of the anti-clogging composite coating material comprises the following steps:

[0019] S1: Surface pretreatment: Use an ultrasonic cleaning machine to clean the surface of the irrigation channel 5 with ethanol to remove oil stains and impurities; use low-temperature plasma to treat the surface of the irrigation channel 5 to increase surface activity and improve coating adhesion;

[0020] S2: Base coating coating: Use high-pressure airless spraying equipment to control the spraying pressure of 0.3-0.5MPa and the spraying distance of 20-30cm, and evenly spray the base coating material on the surface of the sprinkler flow channel 5, with a thickness of 10-15 microns, pre-cured at 80°C for 30 minutes, and then completely cured at 120°C for 1 hour, and the base coating 1 is formed after curing; after the base coating is cured, spray a layer of silane coupling agent with a spray thickness of 1-2 microns, let it stand at room temperature for 10 minutes, and then dry it at 80°C for 20 minutes; a chemical bridging layer is formed, and the siloxane group in the silane coupling agent reacts with the hydroxyl group of the epoxy resin in the base coating 1, and at the same time, its organic group forms a chemical bond with the polyurethane of the sandwich coating 2;

[0021] S3: Interlayer coating: Use high-pressure airless spraying equipment to control the spraying pressure of 0.3-0.5MPa and the spraying distance of 20-30cm, spray the interlayer coating material evenly on the base coating, control the thickness to be 20-30 microns, cure at 100°C for 1 hour, and then post-cure at 150°C for 30 minutes to form an interlayer coating 2 after curing; spray a functional monomer grafting liquid with a concentration of 5-10% on the surface of the interlayer coating to form an active surface; these monomers can form hydrogen bonds or van der Waals forces with the fluorine atoms in the polytetrafluoroethylene of the adjacent coating to enhance the bonding force; UV curing for 5 minutes after spraying;

[0022] S4: coating of the surface coating: using high-pressure airless spraying equipment to control the spraying pressure of 0.3-0.5MPa and the spraying distance of 20-30cm, the surface coating material is evenly sprayed on the sandwich coating 2, and the thickness is controlled at 5-10 microns; curing at 180°C for 30 minutes to ensure that the polytetrafluoroethylene and the nano-silver particles are fully combined;

[0023] S5: Post-treatment: After the surface coating is applied, a layer of ultra-thin siloxane film is deposited on the surface using plasma enhanced chemical vapor deposition technology to further enhance the hydrophobicity and wear resistance; ultraviolet rays are used to irradiate the coating surface to further cross-link the coating molecules and improve durability.

[0024] A drip irrigation tape emitter anti-clogging composite coating material is suitable for an emitter, which uses the above-mentioned drip irrigation tape emitter anti-clogging composite coating material. The anti-clogging composite coating material is suitable for an emitter flow channel 5 with a cross-section that is wide at the top and narrow at the bottom.

[0025] Beneficial effects of the present invention:

[0026] ① The comprehensive anti-clogging ability is significantly improved: Multifunctional synergy: Through the three-layer composite design of base coating (enhanced adhesion), interlayer coating (wear resistance and corrosion resistance) and surface coating (hydrophobic and antibacterial), biological clogging (inhibition of microbial attachment), chemical clogging (reduction of mineral deposition) and physical clogging (reduction of particle retention) are solved simultaneously to achieve all-round protection.

[0027] ②The interface bonding force is greatly enhanced: chemical bonding and physical anchoring: through the silane coupling agent bridging layer and plasma surface activation technology, the adhesion between the coating and the polyethylene substrate is improved, and the interlayer bonding strength is increased by more than 30%, effectively avoiding delamination.

[0028] ③Excellent long-term durability: Nanomaterial enhancement: The introduction of nano-silicon dioxide (hardness HV ≥ 0.3GPa) and graphene oxide (high chemical inertness) significantly improves the wear resistance and corrosion resistance of the coating.

[0029] ④Outstanding process economy: Low-cost industrial production: Using standardized spraying equipment and plasma pretreatment technology, coating efficiency is increased by 50%, and no complex mold processing is required, reducing production costs by 20%-30%.

[0030] ⑤Universal applicability: Adaptable to complex structures: Especially suitable for labyrinth flow channel design with a cross-section of "wide at the top and narrow at the bottom". The coating thickness is controllable (10-30μm) and does not affect the original energy dissipation performance of the flow channel.

[0031] ⑥ Expanded application potential: This technology can be extended to other agricultural irrigation equipment or the inner wall protection of industrial pipelines, and has broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic diagram of an emitter structure applicable to a drip irrigation tape emitter anti-clogging composite coating material provided in an embodiment of the present invention;

[0034] Figure 2 A cross-sectional view of an anti-clogging composite coating of a drip irrigation tape emitter provided in an embodiment of the present invention;

[0035] Figure 3 The present invention is a schematic flow chart of a coating method of an anti-clogging composite coating material for a drip irrigation tape emitter.

[0036] Icons: 1. Base coating; 2. Interlayer coating; 3. Surface coating; 4. Irrigator; 5. Irrigator flow channel. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Embodiment one:

[0039] like Figure 2 As shown, the first embodiment of the present invention provides a composite coating material for drip irrigation tape emitter anti-clogging, including a base coating 1, an intermediate coating 2 and a surface coating 3;

[0040] The base coating 1 is composed of epoxy resin, silane coupling agent KH-560, curing agent and solvent, and is used to enhance the adhesion between the coating and the substrate; the weight percentages of the base coating 1 components are as follows: epoxy resin accounts for 60%, silane coupling agent accounts for 5%, curing agent accounts for 10%, and solvent accounts for 25%;

[0041] The sandwich coating 2 is composed of polyurethane, nano-silicon dioxide, dispersant and solvent, and is used to provide wear resistance and corrosion resistance; the weight percentages of the components of the sandwich coating 2 are as follows: polyurethane accounts for 70%; nano-silicon dioxide accounts for 5%; dispersant accounts for 2%; and solvent accounts for 23%.

[0042] The surface coating 3 is composed of polytetrafluoroethylene emulsion, nano silver particles, graphene oxide, silane coupling agent and deionized water, and is used to provide hydrophobicity and antibacterial properties. The weight percentages of the components of the surface coating 3 are as follows: polytetrafluoroethylene emulsion accounts for 50%; nano silver particles account for 2%; graphene oxide accounts for 1%; silane coupling agent accounts for 3%; and deionized water accounts for 44%.

[0043] Embodiment 2:

[0044] The second embodiment provides a method for preparing a drip irrigation tape emitter anti-clogging composite coating material, using the above-mentioned drip irrigation tape emitter anti-clogging composite coating material, which specifically includes the following steps:

[0045] S1: Preparation of base coating 1: Accurately weigh epoxy resin, silane coupling agent, curing agent and solvent, and filter to ensure that the raw materials are free of impurities; add epoxy resin and silane coupling agent into a stirring container, and stir at a speed of 500-800rpm for 10 minutes; slowly add curing agent and continue stirring for 15 minutes to ensure uniform mixing; add solvent acetone and adjust the viscosity to 200-300mPa·s; filter the mixture with a 200-mesh filter to remove undissolved particles or impurities; store the mixture in a sealed container to avoid contact with moisture and dust;

[0046] S2: Preparation of sandwich coating 2: Accurately weigh polyurethane, nano-silica, dispersant and solvent; ensure that nano-silica is dry and free of moisture; add nano-silica and dispersant to a small amount of solvent, and use a high-speed disperser to pre-disperse for 10 minutes at a speed of 2000-3000rpm; add the pre-dispersed nano-silica to polyurethane and stir at a speed of 800-1000rpm for 20 minutes; slowly add the remaining solvent and adjust the viscosity to 300-400mPa·s; grind the mixture with a three-roll mill to ensure that the nano-silica is evenly dispersed and the particle size is ≤100nm; filter the mixture with a 300-mesh filter to remove agglomerated particles; store the mixture in a sealed container to avoid contact with moisture and high temperature;

[0047] S3: Preparation of surface coating 3: Accurately weigh polytetrafluoroethylene emulsion, nanosilver particles, graphene oxide, silane coupling agent and deionized water; ensure that the nanosilver particles and graphene oxide are evenly dispersed; add the nanosilver particles and graphene oxide to a small amount of deionized water and disperse them using an ultrasonic disperser for 30 minutes; add the pre-dispersed nanosilver and graphene oxide to the polytetrafluoroethylene emulsion and stir at a speed of 500-800rpm for 15 minutes; add the silane coupling agent and continue stirring for 10 minutes; add the remaining deionized water and adjust the viscosity to 100-200mPa·s; filter the mixture using a 200-mesh filter to remove undispersed particles; store the mixture in a sealed container to avoid light and high temperature.

[0048] Embodiment three:

[0049] like Figure 3 As shown, the second embodiment provides a coating method of a drip irrigation tape emitter anti-clogging composite coating material, using the above-mentioned drip irrigation tape emitter anti-clogging composite coating material, which specifically includes the following steps:

[0050] S1: Surface pretreatment: Use an ultrasonic cleaning machine to clean the surface of the irrigation channel 5 with ethanol to remove oil stains and impurities; use low-temperature plasma to treat the surface of the irrigation channel 5 to increase surface activity and improve coating adhesion;

[0051] S2: Base coating coating: Use high-pressure airless spraying equipment to control the spraying pressure of 0.3-0.5MPa and the spraying distance of 20-30cm, and evenly spray the base coating material on the surface of the sprinkler flow channel 5, with a thickness of 10-15 microns, pre-cured at 80°C for 30 minutes, and then completely cured at 120°C for 1 hour, and the base coating 1 is formed after curing; after the base coating is cured, spray a layer of silane coupling agent KH-560 with a spraying thickness of 1-2 microns, let it stand at room temperature for 10 minutes, and then dry it at 80°C for 20 minutes; a chemical bridging layer is formed, and the siloxane group in the silane coupling agent reacts with the hydroxyl group of the epoxy resin in the base coating 1, and at the same time, its organic group forms a chemical bond with the polyurethane of the sandwich coating 2;

[0052] S3: Interlayer coating: Use high-pressure airless spraying equipment to control the spraying pressure of 0.3-0.5MPa and the spraying distance of 20-30cm, spray the interlayer coating material evenly on the base coating, control the thickness to be 20-30 microns, cure at 100°C for 1 hour, and then post-cure at 150°C for 30 minutes to form an interlayer coating 2 after curing; spray a functional monomer methacrylic acid grafting liquid with a concentration of 5-10% on the surface of the interlayer coating to form an active surface; these monomers can form hydrogen bonds or van der Waals forces with the fluorine atoms in the polytetrafluoroethylene of the adjacent coating to enhance the bonding force; UV curing for 5 minutes after spraying;

[0053] S4: coating of the surface coating: using high-pressure airless spraying equipment to control the spraying pressure of 0.3-0.5MPa and the spraying distance of 20-30cm, the surface coating material is evenly sprayed on the sandwich coating 2, and the thickness is controlled at 5-10 microns; curing at 180°C for 30 minutes to ensure that the polytetrafluoroethylene and the nano-silver particles are fully combined;

[0054] S5: Post-treatment: After the surface coating is applied, a layer of ultra-thin siloxane film is deposited on the surface using plasma enhanced chemical vapor deposition technology to further enhance the hydrophobicity and wear resistance; ultraviolet rays are used to irradiate the coating surface to further cross-link the coating molecules and improve durability.

[0055] Embodiment 4:

[0056] like Figure 1 As shown, the first embodiment of the present invention provides an emitter suitable for the anti-clogging composite coating material of a drip irrigation tape emitter, wherein the cross section of the emitter flow channel 5 is a structure with a wide upper portion and a narrow lower portion.

[0057] 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite coating material for drip irrigation tape emitters, characterized in that: It comprises a base coating (1), an intermediate coating (2) and a surface coating (3); The base coating (1) is composed of epoxy resin, silane coupling agent, curing agent and solvent, and is used to enhance the adhesion between the coating and the substrate; The interlayer coating (2) is composed of polyurethane, nano-silicon dioxide, a dispersant and a solvent, and is used to provide wear resistance and corrosion resistance; The surface coating (3) is composed of polytetrafluoroethylene emulsion, nano silver particles, graphene oxide, silane coupling agent and deionized water, and is used to provide hydrophobicity and antibacterial properties.

2. The anti-clogging composite coating material for a drip irrigation tape emitter according to claim 1, characterized in that: The weight percentages of the components of the base coating (1) are as follows: epoxy resin accounts for 60%, silane coupling agent accounts for 5%, curing agent accounts for 10% and solvent accounts for 25%.

3. The anti-clogging composite coating material for a drip irrigation tape emitter according to claim 1, characterized in that: The weight percentages of the components of the sandwich coating (2) are as follows: polyurethane accounts for 70%, nano silicon dioxide accounts for 5%, dispersant accounts for 2%, and solvent accounts for 23%.

4. The anti-clogging composite coating material for a drip irrigation tape emitter according to claim 3, characterized in that: The components of the surface coating (3) are as follows by weight percentage: polytetrafluoroethylene emulsion accounts for 50%; nano silver particles account for 2%; graphene oxide accounts for 1%; silane coupling agent accounts for 3%; and deionized water accounts for 44%.

5. A method for preparing an anti-clogging composite coating material for a drip irrigation tape emitter, characterized in that: The anti-clogging composite coating material for a drip irrigation tape emitter as claimed in any one of claims 1 to 4 is used, and the preparation method of the anti-clogging composite coating material comprises the following steps: S1: Preparing a base coating (1): Accurately weigh epoxy resin, silane coupling agent, curing agent and solvent, and filter to ensure that the raw materials are free of impurities; add epoxy resin and silane coupling agent into a stirring container, and stir at a speed of 500-800 rpm for 10 minutes; slowly add curing agent and continue stirring for 15 minutes to ensure uniform mixing; add solvent and adjust the viscosity to 200-300 mPa·s; filter the mixture using a 200 mesh filter to remove undissolved particles or impurities; store the mixture in a sealed container to avoid contact with moisture and dust; S2: Preparation of interlayer coating (2): Accurately weigh polyurethane, nano-silica, dispersant and solvent; ensure that nano-silica is dry and free of moisture; add nano-silica and dispersant to a small amount of solvent, and pre-disperse for 10 minutes at 2000-3000 rpm using a high-speed disperser; add the pre-dispersed nano-silica to polyurethane, and stir at 800-1000 rpm for 20 minutes; slowly add the remaining solvent and adjust the viscosity to 300-400 mPa·s; grind the mixture using a three-roll grinder to ensure that the nano-silica is evenly dispersed and the particle size is ≤100 nm; filter the mixture using a 300-mesh filter to remove agglomerated particles; store the mixture in a sealed container to avoid contact with moisture and high temperature; S3: Preparation of surface coating (3): Accurately weigh polytetrafluoroethylene emulsion, nanosilver particles, graphene oxide, silane coupling agent and deionized water; ensure that the nanosilver particles and graphene oxide are evenly dispersed; add the nanosilver particles and graphene oxide to a small amount of deionized water, and disperse them using an ultrasonic disperser for 30 minutes; add the pre-dispersed nanosilver and graphene oxide to the polytetrafluoroethylene emulsion, and stir at a speed of 500-800rpm for 15 minutes; add the silane coupling agent and continue stirring for 10 minutes; add the remaining deionized water and adjust the viscosity to 100-200mPa·s; filter the mixture using a 200-mesh filter to remove undispersed particles; store the mixture in a sealed container to avoid light and high temperature.

6. A coating method for an anti-clogging composite coating material for a drip irrigation tape emitter, characterized in that: The anti-clogging composite coating material for a drip irrigation tape emitter as claimed in any one of claims 1 to 4 is used, and the coating method of the anti-clogging composite coating material comprises the following steps: S1: Surface pretreatment: using an ultrasonic cleaning machine to clean the surface of the irrigation channel (5) with ethanol to remove oil stains and impurities; using low-temperature plasma to treat the surface of the irrigation channel (5) to increase surface activity and improve coating adhesion; S2: Base coating coating: Use high-pressure airless spraying equipment to control the spraying pressure of 0.3-0.5MPa and the spraying distance of 20-30cm, and evenly spray the base coating material on the surface of the sprinkler flow channel (5) to a thickness of 10-15 microns. Pre-cure at 80°C for 30 minutes, and then completely cure at 120°C for 1 hour to form a base coating (1) after curing; After the base coating is cured, spray a layer of silane coupling agent with a spray thickness of 1-2 microns, let it stand at room temperature for 10 minutes, and then dry it at 80°C for 20 minutes to form a chemical bridging layer, wherein the siloxane group in the silane coupling agent reacts with the hydroxyl group of the epoxy resin in the base coating (1), and at the same time, its organic group forms a chemical bond with the polyurethane of the interlayer coating (2); S3: Interlayer coating: Use high-pressure airless spraying equipment to control the spraying pressure of 0.3-0.5MPa and the spraying distance of 20-30cm, and evenly spray the interlayer coating material on the base coating with a thickness of 20-30 microns, and cure at 100°C for 1 hour, and then post-cure at 150°C for 30 minutes to form an interlayer coating (2) after curing; spray a functional monomer grafting liquid with a concentration of 5-10% on the surface of the interlayer coating to form an active surface; These monomers can form hydrogen bonds or van der Waals forces with the fluorine atoms in the adjacent coating polytetrafluoroethylene to enhance the bonding strength; UV curing for 5 minutes after spraying; S4: coating the surface coating: using high-pressure airless spraying equipment to control the spraying pressure of 0.3-0.5 MPa and the spraying distance of 20-30 cm, the surface coating material is evenly sprayed on the sandwich coating (2), and the thickness is controlled to be 5-10 microns; curing at 180° C. for 30 minutes to ensure that the polytetrafluoroethylene and the nano-silver particles are fully combined; S5: Post-treatment: After the surface coating is applied, a layer of ultra-thin siloxane film is deposited on the surface using plasma enhanced chemical vapor deposition technology to further enhance the hydrophobicity and wear resistance; ultraviolet rays are used to irradiate the coating surface to further cross-link the coating molecules and improve durability.

7. A drip irrigation tape emitter with an anti-clogging composite coating material, characterized in that: The anti-clogging composite coating material for a drip irrigation tape emitter as claimed in any one of claims 1 to 4 is used, and the anti-clogging composite coating material is suitable for an emitter flow channel (5) having a structure in which the cross section is wide at the top and narrow at the bottom.

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