An impact-resistant coating for the inner wall of a single screw pump and its preparation method

Abstract

This invention discloses an impact-resistant coating for the inner wall of a single screw pump. The raw materials include epoxy resin, filler powder, an alkylating agent, a curing agent, and a solvent. The coating layer prepared by the method described in this invention exhibits good impact resistance and excellent impact performance. When applied to the inner wall of a single screw pump, it can be used effectively even in media with high impact loads, thus improving the durability of the single screw pump.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to an impact-resistant coating for the inner wall of a single screw pump and its preparation method. Background Technology

[0002] The single screw pump, as an internally meshing, closed-circuit positive displacement pump, relies on the meshing of the screw and stator bushing to form a continuous sealed chamber. The axial movement of this chamber enables the intake and discharge of the medium. Due to its strong adaptability to high-viscosity, particulate-containing, and sensitive media, as well as its uniform flow rate, low pressure pulsation, and high self-priming capability, this type of pump is widely used in oil extraction, chemical transportation, environmental treatment, and food and pharmaceutical industries. However, single screw pumps face severe wear problems in actual operating conditions, which has become a major bottleneck restricting their service life and operational reliability. For example, when conveying media containing hard fillers such as glass fiber, calcium carbonate, and minerals, these solid particles exert severe scraping and impact on the metal surface under the high-speed rotation of the rotor, resulting in typical abrasive wear. Summary of the Invention

[0003] Therefore, the present invention provides an impact-resistant coating for the inner wall of a single screw pump, the raw materials of which include epoxy resin, filler powder, an alkylating agent, a curing agent, and a solvent. The preparation steps of the filler powder include: (1) Mix acetic acid, ethanol and deionized water evenly in a reaction vessel, then add tetraethyl silicate and cerium nitrate hexahydrate to the reaction vessel, mix well after adding, and then add tetrabutyl titanate; then seal the reaction vessel, heat it with hydrothermal heat, cool it to room temperature after the heat preservation is completed, open the reaction vessel, separate the solid and liquid, wash the solid phase, dry it, and obtain composite powder. (2) Prepare an aqueous solution of 3,4-dihydroxyphenylpropionic acid, immerse the composite powder in the aqueous solution of 3,4-dihydroxyphenylpropionic acid to obtain a mixture, place the mixture in a vacuum chamber, vacuum it, maintain pressure, remove the mixture after the pressure is maintained, separate the solid and liquid, wash the solid phase, dry it, immerse it in ethanol after drying, stir and disperse it to obtain a dispersion, then add n-hexadecylamine, stir and mix it after adding the material, then add triethylamine, heat it in a water bath and keep it warm after adding the material, separate the solid and liquid after the heat is maintained, wash the solid phase, dry it to obtain modified particles; (3) Gallic acid was added to N,N-dimethylformamide and stirred until fully dissolved. Then, the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine were added to the solution. After the addition was completed, the mixture was kept warm in a water bath and stirred. After stirring, the solid and liquid were separated, the solid phase was washed and dried to obtain the filler powder.

[0004] Further, the preparation method of the coating layer is as follows: the epoxy resin is heated and kept at a certain temperature to reduce its viscosity, then the filler powder and the aliphatic agent are added to the solvent and stirred and dispersed. After dispersion, the mixture is poured into the insulated epoxy resin and stirred and mixed evenly. Then the curing agent is added and stirred evenly. The mixture is coated on the inner wall surface of the single screw pump, cured at room temperature, and then heated and dried to obtain the coating layer.

[0005] Furthermore, the azo agent is γ-aminopropyltriethoxysilane, the curing agent is T-31 curing agent, and the solvent is acetone.

[0006] Further, the raw materials are as follows by weight: 100 parts epoxy resin, 3-5 parts filler powder, 2-3 parts azo agent, 20-25 parts curing agent, and 28-30 parts solvent.

[0007] Further, the epoxy resin is heated to 80°C to reduce its viscosity, stirred for 2-3 minutes, and then heated to 120°C and kept warm.

[0008] Further, in step (1), the ratio of acetic acid, ethanol, deionized water, tetraethyl silicate, cerium nitrate hexahydrate, and tetrabutyl titanate used is acetic acid: ethanol: deionized water: tetraethyl silicate: cerium nitrate hexahydrate: tetrabutyl titanate = 4-5 mL: 50 mL: 20-25 mL: 0.3-0.4 g: 0.01-0.02 g: 2.5-3 g; the heating hydrothermal insulation temperature is 160-170℃, and the insulation time is 10-15 h.

[0009] Further, in step (2), the concentration of 3,4-dihydroxyphenylpropionic acid in the aqueous solution of 3,4-dihydroxyphenylpropionic acid is 3-4 mg / mL, and the solvent is water; the ratio of the amount of composite powder soaked in the aqueous solution of 3,4-dihydroxyphenylpropionic acid is 1 g of composite powder to 30-50 mL of aqueous solution of 3,4-dihydroxyphenylpropionic acid.

[0010] Further, in step (2), the ratio of the amount of the dried solid phase soaked in ethanol is solid phase: ethanol = 1g: 50-100mL, and the ratio of the amount of hexadecylamine and triethylamine added to the mass of the dried solid phase added to ethanol is solid phase: hexadecylamine: triethylamine = 1g: 1-1.2g: 2-3g; after adding the materials, the water bath is heated to 55-60℃ and kept warm for 15-20h.

[0011] Further, in step (3), the ratio of gallic acid to N,N-dimethylformamide is gallic acid:N,N-dimethylformamide = 8-10 g: 100 mL. The ratio of the amount of the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine added to the solution to the amount of gallic acid is gallic acid:modified particles:1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride:4-dimethylaminopyridine = 8-10 g:3-4 g:10-12 g:1.2-1.4 g. The solution is heated in a water bath to 55-60°C and stirred for at least 45 hours.

[0012] The beneficial effects of this invention are as follows: the coating layer prepared by the method described in this invention has good strength and exhibits excellent impact resistance. When applied to the inner wall of a single-screw pump, it performs well even in applications with high impact forces, improving the pump's durability. This invention first prepares a composite powder as the matrix powder for the filler. Then, 3,4-dihydroxyphenylpropionic acid is used to modify the surface of the matrix powder, modifying the powder surface with catechol groups. Next, a Michael addition reaction is performed between the amino groups of hexadecylamine and triethylamine and the catechol groups to improve the powder's hydrophobicity. Simultaneously, this improves the bonding force between the powder and the resin matrix, increases the interfacial adhesion strength, increases the coating density, and reduces interfacial defects, thereby improving the coating's strength. Furthermore, the improved interphase bonding allows for effective stress transfer between the components of the composite coating, thus improving its mechanical properties. Finally, gallic acid treatment of the powder improves the dispersibility of the filler in the resin matrix, reduces agglomeration, and further improves the overall impact resistance of the coating. Detailed Implementation

[0013] The present invention will be further described below with reference to the embodiments.

[0014] Example 1

[0015] A coating for the inner wall of an impact-resistant single screw pump, comprising epoxy resin, filler powder, an aliphatic agent, a curing agent, and a solvent, wherein the raw materials are in the following proportions by weight: 100 parts epoxy resin, 3 parts filler powder, 2 parts aliphatic agent, 20 parts curing agent, and 28 parts solvent; wherein the aliphatic agent is selected as γ-aminopropyltriethoxysilane, the curing agent is selected as T-31 curing agent, and the solvent is selected as acetone; the preparation steps of the filler powder include: (1) Acetic acid, ethanol and deionized water are mixed and stirred evenly in a reaction vessel. Then, tetraethyl silicate and cerium nitrate hexahydrate are added to the reaction vessel. After adding the materials, the mixture is stirred for 10 min to mix evenly. Then, tetrabutyl titanate is added. The ratio of acetic acid, ethanol, deionized water, tetraethyl silicate, cerium nitrate hexahydrate and tetrabutyl titanate used is acetic acid: ethanol: deionized water: tetraethyl silicate: cerium nitrate hexahydrate: tetrabutyl titanate = 4 mL: 50 mL: 20 mL: 0.3 g: 0.01 g: 2.5 g. Then, the reaction vessel is sealed and heated to 160°C for hydrothermal heat preservation for 10 h. After the heat preservation is completed, the mixture is cooled to room temperature. The reaction vessel is opened and the solid and liquid are separated. The solid phase is washed with ethanol 3 times and dried at 100°C for 1 h to obtain composite powder. (2) Prepare an aqueous solution of 3,4-dihydroxyphenylpropionic acid, wherein the concentration of 3,4-dihydroxyphenylpropionic acid in the aqueous solution is 3 mg / mL, and the solvent is water; soak the composite powder in the aqueous solution of 3,4-dihydroxyphenylpropionic acid to obtain a mixture, wherein the ratio of the composite powder to the aqueous solution of 3,4-dihydroxyphenylpropionic acid is 1 g: 40 mL; place the mixture in a vacuum chamber, evacuate to 0.01 atmospheres, and maintain the pressure for 2 hours. The negative pressure condition ensures sufficient contact between the solution and the powder surface, and also reduces the oxygen content and reaction rate. The oxidation of the material was carried out; after the pressure holding was completed, the mixture was taken out, and the solid and liquid were separated. The solid phase was washed three times with ethanol, dried at 100°C for 1 hour, and then soaked in ethanol. The ratio of the amount of the dried solid phase soaked in ethanol was solid phase: ethanol = 1 g: 50 mL. The mixture was stirred and dispersed for 30 minutes to obtain a dispersion. Then, hexadecylamine was added, and the mixture was stirred for 10 minutes to mix it. Then, triethylamine was added. The ratio of the amount of hexadecylamine and triethylamine added to the mass of the dried solid phase in ethanol was solid phase: hexadecylamine: triethylamine = 1 g: 1 g: 2 g. After the addition, the mixture was heated to 60°C in a water bath and kept at that temperature for 15 hours. After the temperature was maintained, the solid and liquid were separated. The solid phase was washed three times with ethanol and dried at 100°C for 1 hour to obtain modified particles. (3) Add gallic acid to N,N-dimethylformamide in a ratio of gallic acid to N,N-dimethylformamide of 8 g to 100 mL. Stir until fully dissolved. Then add the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine to the solution in a ratio of gallic acid to modified particles: modified particles: 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride. Carbodiimide hydrochloride: 4-dimethylaminopyridine = 8g: 3g: 10g: 1.2g; After the addition is completed, heat in a water bath to 60℃ and stir for 45h. After stirring, separate the solid and liquid phases. Wash the solid phase twice with ethanol and twice with deionized water. Dry at 100℃ for 1h to obtain the filler powder.

[0016] The coating layer is prepared as follows: the epoxy resin is heated to 80°C and stirred for 2 minutes to reduce its viscosity. The temperature is then raised to 120°C and kept at that temperature. The filler powder and aliphatic agent are added to the solvent and stirred for 2 hours to disperse them. After dispersion, the mixture is poured into the epoxy resin kept at 120°C and stirred for 30 minutes to mix evenly. The curing agent is then added and stirred for 5 minutes to mix evenly. The mixture is then coated onto the surface of a test 316 stainless steel plate treated according to standard GB1765-1979 (1989), cured at room temperature for 30 minutes, and then heated to 100°C and dried for 20 minutes to obtain the coating layer.

[0017] Example 2

[0018] A coating for the inner wall of an impact-resistant single-screw pump, comprising epoxy resin, filler powder, an aliphatic agent, a curing agent, and a solvent, wherein the raw materials are in the following weight proportions: 100 parts epoxy resin, 4 parts filler powder, 2 parts aliphatic agent, 20 parts curing agent, and 29 parts solvent; wherein the aliphatic agent is selected as γ-aminopropyltriethoxysilane, the curing agent is selected as T-31 curing agent, and the solvent is selected as acetone; the preparation steps of the filler powder include: (1) Acetic acid, ethanol and deionized water are mixed and stirred evenly in a reaction vessel. Then, tetraethyl silicate and cerium nitrate hexahydrate are added to the reaction vessel. After adding the materials, the mixture is stirred for 10 min to mix evenly. Then, tetrabutyl titanate is added. The ratio of acetic acid, ethanol, deionized water, tetraethyl silicate, cerium nitrate hexahydrate and tetrabutyl titanate used is acetic acid: ethanol: deionized water: tetraethyl silicate: cerium nitrate hexahydrate: tetrabutyl titanate = 4 mL: 50 mL: 20 mL: 0.3 g: 0.01 g: 2.5 g. Then, the reaction vessel is sealed and heated to 160°C for hydrothermal heat preservation for 10 h. After the heat preservation is completed, the mixture is cooled to room temperature. The reaction vessel is opened and the solid and liquid are separated. The solid phase is washed with ethanol 3 times and dried at 100°C for 1 h to obtain composite powder. (2) Prepare an aqueous solution of 3,4-dihydroxyphenylpropionic acid, wherein the concentration of 3,4-dihydroxyphenylpropionic acid in the aqueous solution is 3 mg / mL, and the solvent is water; soak the composite powder in the aqueous solution of 3,4-dihydroxyphenylpropionic acid to obtain a mixture, wherein the ratio of the composite powder to the aqueous solution of 3,4-dihydroxyphenylpropionic acid is 1 g: 40 mL; place the mixture in a vacuum chamber, evacuate to 0.01 atmospheres, and maintain the pressure for 2 hours. Under negative pressure, on the one hand, the solution and powder surface can be fully contacted, and on the other hand, the oxygen content can be reduced, thus reducing the reaction. The oxidation of the material was carried out. After the pressure holding was completed, the mixture was taken out, and the solid and liquid were separated. The solid phase was washed three times with ethanol, dried at 100°C for 1 hour, and then soaked in ethanol. The ratio of the amount of the dried solid phase soaked in ethanol was 1 g: 50 mL. The mixture was stirred and dispersed for 30 minutes to obtain a dispersion. Then, hexadecylamine was added, and the mixture was stirred for 10 minutes to mix it. Then, triethylamine was added. The ratio of the amount of hexadecylamine and triethylamine added to the mass of the dried solid phase in ethanol was 1 g: 1.1 g: 2 g. After the addition, the mixture was heated to 60°C in a water bath and kept at that temperature for 15 hours. After the temperature was maintained, the solid and liquid were separated. The solid phase was washed three times with ethanol and dried at 100°C for 1 hour to obtain modified particles. (3) Add gallic acid to N,N-dimethylformamide. The ratio of gallic acid to N,N-dimethylformamide is 9 g: 100 mL. Stir until fully dissolved. Then add the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine to the solution. The ratio of the amount of the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine added to the amount of gallic acid is gallic acid: modified particles: 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride. Carbodiimide hydrochloride: 4-dimethylaminopyridine = 9g: 3g: 11g: 1.3g; After the addition is completed, heat in a water bath to 60℃ and stir for 45h. After stirring, separate the solid and liquid phases. Wash the solid phase twice with ethanol and twice with deionized water. Dry at 100℃ for 1h to obtain the filler powder.

[0019] The coating layer is prepared as follows: the epoxy resin is heated to 80°C and stirred for 2 minutes to reduce its viscosity. The temperature is then raised to 120°C and kept at that temperature. The filler powder and aliphatic agent are added to the solvent and stirred for 2 hours to disperse them. After dispersion, the mixture is poured into the epoxy resin kept at 120°C and stirred for 30 minutes to mix evenly. The curing agent is then added and stirred for 5 minutes to mix evenly. The mixture is then coated onto the surface of a test 316 stainless steel plate treated according to standard GB1765-1979 (1989), cured at room temperature for 30 minutes, and then heated to 100°C and dried for 20 minutes to obtain the coating layer.

[0020] Example 3

[0021] A coating for the inner wall of an impact-resistant single screw pump, comprising epoxy resin, filler powder, an aliphatic agent, a curing agent, and a solvent, wherein the raw materials are in the following weight proportions: 100 parts epoxy resin, 4 parts filler powder, 3 parts aliphatic agent, 25 parts curing agent, and 29 parts solvent; wherein the aliphatic agent is selected as γ-aminopropyltriethoxysilane, the curing agent is selected as T-31 curing agent, and the solvent is selected as acetone; the preparation steps of the filler powder include: (1) Acetic acid, ethanol and deionized water are mixed and stirred evenly in a reaction vessel. Then, tetraethyl silicate and cerium nitrate hexahydrate are added to the reaction vessel. After adding the materials, the mixture is stirred for 10 min to mix evenly. Then, tetrabutyl titanate is added. The ratio of acetic acid, ethanol, deionized water, tetraethyl silicate, cerium nitrate hexahydrate and tetrabutyl titanate is acetic acid: ethanol: deionized water: tetraethyl silicate: cerium nitrate hexahydrate: tetrabutyl titanate = 5 mL: 50 mL: 25 mL: 0.4 g: 0.02 g: 3 g. Then, the reaction vessel is sealed and heated to 160°C for hydrothermal heat preservation for 10 h. After the heat preservation is completed, the mixture is cooled to room temperature. The reaction vessel is opened and the solid and liquid are separated. The solid phase is washed with ethanol 3 times and dried at 100°C for 1 h to obtain composite powder. (2) Prepare an aqueous solution of 3,4-dihydroxyphenylpropionic acid, wherein the concentration of 3,4-dihydroxyphenylpropionic acid in the aqueous solution is 4 mg / mL, and the solvent is water; soak the composite powder in the aqueous solution of 3,4-dihydroxyphenylpropionic acid to obtain a mixture, wherein the ratio of the composite powder to the aqueous solution of 3,4-dihydroxyphenylpropionic acid is 1 g: 40 mL; place the mixture in a vacuum chamber, evacuate to 0.01 atmospheres, and maintain the pressure for 2 hours. Under negative pressure, on the one hand, the solution and powder surface can be fully contacted, and on the other hand, the oxygen content can be reduced, thus reducing the reaction. The oxidation of the material was carried out. After the pressure holding was completed, the mixture was taken out, and the solid and liquid were separated. The solid phase was washed three times with ethanol, dried at 100°C for 1 hour, and then soaked in ethanol. The ratio of the amount of the dried solid phase soaked in ethanol was solid phase: ethanol = 1 g: 50 mL. The mixture was stirred and dispersed for 30 minutes to obtain a dispersion. Then, hexadecylamine was added, and the mixture was stirred for 10 minutes to mix it. Then, triethylamine was added. The ratio of the amount of hexadecylamine and triethylamine added to the mass of the dried solid phase in ethanol was solid phase: hexadecylamine: triethylamine = 1 g: 1.1 g: 3 g. After the addition, the mixture was heated to 60°C in a water bath and kept at that temperature for 15 hours. After the temperature was maintained, the solid and liquid were separated. The solid phase was washed three times with ethanol and dried at 100°C for 1 hour to obtain modified particles. (3) Add gallic acid to N,N-dimethylformamide. The ratio of gallic acid to N,N-dimethylformamide is 9 g: 100 mL. Stir until fully dissolved. Then add the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine to the solution. The ratio of the amount of the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine added to the amount of gallic acid is gallic acid: modified particles: 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride. Carbodiimide hydrochloride: 4-dimethylaminopyridine = 9g: 4g: 11g: 1.3g; After the addition is completed, heat in a water bath to 60℃ and stir for 45h. After stirring, separate the solid and liquid phases. Wash the solid phase twice with ethanol and twice with deionized water. Dry at 100℃ for 1h to obtain the filler powder.

[0022] The coating layer is prepared as follows: the epoxy resin is heated to 80°C and stirred for 2 minutes to reduce its viscosity. The temperature is then raised to 120°C and kept at that temperature. The filler powder and aliphatic agent are added to the solvent and stirred for 2 hours to disperse them. After dispersion, the mixture is poured into the epoxy resin kept at 120°C and stirred for 30 minutes to mix evenly. The curing agent is then added and stirred for 5 minutes to mix evenly. The mixture is then coated onto the surface of a test 316 stainless steel plate treated according to standard GB1765-1979 (1989), cured at room temperature for 30 minutes, and then heated to 100°C and dried for 20 minutes to obtain the coating layer.

[0023] Example 4

[0024] A coating for the inner wall of an impact-resistant single-screw pump, comprising epoxy resin, filler powder, an aliphatic agent, a curing agent, and a solvent, wherein the raw materials are in the following weight proportions: 100 parts epoxy resin, 5 parts filler powder, 3 parts aliphatic agent, 25 parts curing agent, and 30 parts solvent; wherein the aliphatic agent is selected as γ-aminopropyltriethoxysilane, the curing agent is selected as T-31 curing agent, and the solvent is selected as acetone; the preparation steps of the filler powder include: (1) Acetic acid, ethanol and deionized water are mixed and stirred evenly in a reaction vessel. Then, tetraethyl silicate and cerium nitrate hexahydrate are added to the reaction vessel. After adding the materials, the mixture is stirred for 10 min to mix evenly. Then, tetrabutyl titanate is added. The ratio of acetic acid, ethanol, deionized water, tetraethyl silicate, cerium nitrate hexahydrate and tetrabutyl titanate is acetic acid: ethanol: deionized water: tetraethyl silicate: cerium nitrate hexahydrate: tetrabutyl titanate = 5 mL: 50 mL: 25 mL: 0.4 g: 0.02 g: 3 g. Then, the reaction vessel is sealed and heated to 160°C for hydrothermal heat preservation for 10 h. After the heat preservation is completed, the mixture is cooled to room temperature. The reaction vessel is opened and the solid and liquid are separated. The solid phase is washed with ethanol 3 times and dried at 100°C for 1 h to obtain composite powder. (2) Prepare an aqueous solution of 3,4-dihydroxyphenylpropionic acid, wherein the concentration of 3,4-dihydroxyphenylpropionic acid in the aqueous solution is 4 mg / mL, and the solvent is water; soak the composite powder in the aqueous solution of 3,4-dihydroxyphenylpropionic acid to obtain a mixture, wherein the ratio of the composite powder to the aqueous solution of 3,4-dihydroxyphenylpropionic acid is 1 g: 40 mL; place the mixture in a vacuum chamber, evacuate to 0.01 atmospheres, and maintain the pressure for 2 hours. Under negative pressure, on the one hand, the solution and powder surface can be fully contacted, and on the other hand, the oxygen content can be reduced, thus reducing the reaction. The oxidation of the material was carried out. After the pressure holding was completed, the mixture was taken out, and the solid and liquid were separated. The solid phase was washed three times with ethanol, dried at 100°C for 1 hour, and then soaked in ethanol. The ratio of the amount of the dried solid phase soaked in ethanol was 1 g: 50 mL. The mixture was stirred and dispersed for 30 minutes to obtain a dispersion. Then, hexadecylamine was added, and the mixture was stirred for 10 minutes to mix it. Then, triethylamine was added. The ratio of the amount of hexadecylamine and triethylamine added to the mass of the dried solid phase in ethanol was 1 g: 1.2 g: 3 g. After the addition, the mixture was heated to 60°C in a water bath and kept at that temperature for 15 hours. After the temperature was maintained, the solid and liquid were separated. The solid phase was washed three times with ethanol and dried at 100°C for 1 hour to obtain modified particles. (3) Add gallic acid to N,N-dimethylformamide in a ratio of gallic acid to N,N-dimethylformamide of 10 g to 100 mL. Stir until fully dissolved. Then add the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine to the solution in a ratio of gallic acid to modified particles: modified particles: 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride. Carbodiimide hydrochloride: 4-dimethylaminopyridine = 10g: 4g: 12g: 1.4g; after the addition is completed, heat in a water bath to 60℃ and stir for 45h. After stirring, separate the solid and liquid phases. Wash the solid phase twice with ethanol and twice with deionized water. Dry at 100℃ for 1h to obtain the filler powder.

[0025] The coating layer is prepared as follows: the epoxy resin is heated to 80°C and stirred for 2 minutes to reduce its viscosity. The temperature is then raised to 120°C and kept at that temperature. The filler powder and aliphatic agent are added to the solvent and stirred for 2 hours to disperse them. After dispersion, the mixture is poured into the epoxy resin kept at 120°C and stirred for 30 minutes to mix evenly. The curing agent is then added and stirred for 5 minutes to mix evenly. The mixture is then coated onto the surface of a test 316 stainless steel plate treated according to standard GB1765-1979 (1989), cured at room temperature for 30 minutes, and then heated to 100°C and dried for 20 minutes to obtain the coating layer.

[0026] Comparative Example 1 A comparative coating comprises epoxy resin, filler powder, an aliphatic agent, a curing agent, and a solvent, wherein the raw materials are in the following proportions by weight: 100 parts epoxy resin, 4 parts filler powder, 3 parts aliphatic agent, 25 parts curing agent, and 29 parts solvent; wherein the aliphatic agent is selected as γ-aminopropyltriethoxysilane, the curing agent is selected as T-31 curing agent, and the solvent is selected as acetone; the preparation steps of the filler powder include: (1) Acetic acid, ethanol and deionized water are mixed and stirred evenly in a reaction vessel. Then, tetraethyl silicate and cerium nitrate hexahydrate are added to the reaction vessel. After adding the materials, the mixture is stirred for 10 min to mix evenly. Then, tetrabutyl titanate is added. The ratio of acetic acid, ethanol, deionized water, tetraethyl silicate, cerium nitrate hexahydrate and tetrabutyl titanate is acetic acid: ethanol: deionized water: tetraethyl silicate: cerium nitrate hexahydrate: tetrabutyl titanate = 5 mL: 50 mL: 25 mL: 0.4 g: 0.02 g: 3 g. Then, the reaction vessel is sealed and heated to 160°C for hydrothermal heat preservation for 10 h. After the heat preservation is completed, the mixture is cooled to room temperature. The reaction vessel is opened and the solid and liquid are separated. The solid phase is washed with ethanol 3 times and dried at 100°C for 1 h to obtain composite powder. (2) The composite powder is soaked in ethanol, and the ratio of the composite powder soaked in ethanol is 1g:50mL. The mixture is stirred and dispersed for 30min to obtain a dispersion. Then, hexadecylamine is added and stirred for 10min to mix. Triethylamine is then added, and the ratio of the amount of hexadecylamine and triethylamine added to the mass of the composite powder added to ethanol is 1g:1.1g:3g. After the addition, the mixture is heated to 60℃ in a water bath and kept at that temperature for 15h. After the temperature is maintained, the solid and liquid phases are separated. The solid phase is washed three times with ethanol and dried at 100℃ for 1h to obtain modified particles. (3) Add gallic acid to N,N-dimethylformamide. The ratio of gallic acid to N,N-dimethylformamide is 9 g: 100 mL. Stir until fully dissolved. Then add the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine to the solution. The ratio of the amount of the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine added to the amount of gallic acid is gallic acid: modified particles: 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride. Carbodiimide hydrochloride: 4-dimethylaminopyridine = 9g: 4g: 11g: 1.3g; After the addition is completed, heat in a water bath to 60℃ and stir for 45h. After stirring, separate the solid and liquid phases. Wash the solid phase twice with ethanol and twice with deionized water. Dry at 100℃ for 1h to obtain the filler powder.

[0027] The coating layer is prepared as follows: the epoxy resin is heated to 80°C and stirred for 2 minutes to reduce its viscosity. The temperature is then raised to 120°C and kept at that temperature. The filler powder and aliphatic agent are added to the solvent and stirred for 2 hours to disperse them. After dispersion, the mixture is poured into the epoxy resin kept at 120°C and stirred for 30 minutes to mix evenly. The curing agent is then added and stirred for 5 minutes to mix evenly. The mixture is then coated onto the surface of a test 316 stainless steel plate treated according to standard GB1765-1979 (1989), cured at room temperature for 30 minutes, and then heated to 100°C and dried for 20 minutes to obtain the coating layer of this comparative example.

[0028] Comparative Example 2 A comparative coating comprises epoxy resin, filler powder, an aliphatic agent, a curing agent, and a solvent, wherein the raw materials are in the following proportions by weight: 100 parts epoxy resin, 4 parts filler powder, 3 parts aliphatic agent, 25 parts curing agent, and 29 parts solvent; wherein the aliphatic agent is selected as γ-aminopropyltriethoxysilane, the curing agent is selected as T-31 curing agent, and the solvent is selected as acetone; the preparation steps of the filler powder include: (1) Acetic acid, ethanol and deionized water are mixed and stirred evenly in a reaction vessel. Then, tetraethyl silicate and cerium nitrate hexahydrate are added to the reaction vessel. After adding the materials, the mixture is stirred for 10 min to mix evenly. Then, tetrabutyl titanate is added. The ratio of acetic acid, ethanol, deionized water, tetraethyl silicate, cerium nitrate hexahydrate and tetrabutyl titanate is acetic acid: ethanol: deionized water: tetraethyl silicate: cerium nitrate hexahydrate: tetrabutyl titanate = 5 mL: 50 mL: 25 mL: 0.4 g: 0.02 g: 3 g. Then, the reaction vessel is sealed and heated to 160°C for hydrothermal heat preservation for 10 h. After the heat preservation is completed, the mixture is cooled to room temperature. The reaction vessel is opened and the solid and liquid are separated. The solid phase is washed with ethanol 3 times and dried at 100°C for 1 h to obtain composite powder. (2) Prepare an aqueous solution of 3,4-dihydroxyphenylpropionic acid, wherein the concentration of 3,4-dihydroxyphenylpropionic acid in the aqueous solution is 4 mg / mL, and the solvent is water; soak the composite powder in the aqueous solution of 3,4-dihydroxyphenylpropionic acid to obtain a mixture, wherein the ratio of the composite powder soaked in the aqueous solution of 3,4-dihydroxyphenylpropionic acid is 1 g: 40 mL; place the mixture in a vacuum chamber, evacuate to 0.01 atmospheres, and maintain the pressure for 2 hours. The negative pressure condition can ensure that the solution and the powder surface are in full contact, and can reduce the oxygen content and reduce the oxidation of the reactants; after the pressure is maintained, take out the mixture, separate the solid and liquid phases, wash the solid phase with ethanol 3 times, and dry it at 100°C for 1 hour to obtain the modified particles of this comparative example; (3) Add gallic acid to N,N-dimethylformamide. The ratio of gallic acid to N,N-dimethylformamide is 9 g: 100 mL. Stir until fully dissolved. Then add the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine to the solution. The ratio of the amount of the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine added to the amount of gallic acid is gallic acid: modified particles: 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride. Carbodiimide hydrochloride: 4-dimethylaminopyridine = 9g: 4g: 11g: 1.3g; After the addition is completed, heat in a water bath to 60℃ and stir for 45h. After stirring, separate the solid and liquid phases. Wash the solid phase twice with ethanol and twice with deionized water. Dry at 100℃ for 1h to obtain the filler powder.

[0029] The coating layer is prepared as follows: the epoxy resin is heated to 80°C and stirred for 2 minutes to reduce its viscosity. The temperature is then raised to 120°C and kept at that temperature. The filler powder and aliphatic agent are added to the solvent and stirred for 2 hours to disperse them. After dispersion, the mixture is poured into the epoxy resin kept at 120°C and stirred for 30 minutes to mix evenly. The curing agent is then added and stirred for 5 minutes to mix evenly. The mixture is then coated onto the surface of a test 316 stainless steel plate treated according to standard GB1765-1979 (1989), cured at room temperature for 30 minutes, and then heated to 100°C and dried for 20 minutes to obtain the coating layer of this comparative example.

[0030] Comparative Example 3 A comparative coating comprises epoxy resin, filler powder, an aliphatic agent, a curing agent, and a solvent, wherein the raw materials are in the following proportions by weight: 100 parts epoxy resin, 4 parts filler powder, 3 parts aliphatic agent, 25 parts curing agent, and 29 parts solvent; wherein the aliphatic agent is selected as γ-aminopropyltriethoxysilane, the curing agent is selected as T-31 curing agent, and the solvent is selected as acetone; the preparation steps of the filler powder include: (1) Acetic acid, ethanol and deionized water are mixed and stirred evenly in a reaction vessel. Then, tetraethyl silicate and cerium nitrate hexahydrate are added to the reaction vessel. After adding the materials, the mixture is stirred for 10 min to mix evenly. Then, tetrabutyl titanate is added. The ratio of acetic acid, ethanol, deionized water, tetraethyl silicate, cerium nitrate hexahydrate and tetrabutyl titanate is acetic acid: ethanol: deionized water: tetraethyl silicate: cerium nitrate hexahydrate: tetrabutyl titanate = 5 mL: 50 mL: 25 mL: 0.4 g: 0.02 g: 3 g. Then, the reaction vessel is sealed and heated to 160°C for hydrothermal heat preservation for 10 h. After the heat preservation is completed, the mixture is cooled to room temperature. The reaction vessel is opened and the solid and liquid are separated. The solid phase is washed with ethanol 3 times and dried at 100°C for 1 h to obtain composite powder. (2) Prepare an aqueous solution of 3,4-dihydroxyphenylpropionic acid, wherein the concentration of 3,4-dihydroxyphenylpropionic acid in the aqueous solution is 4 mg / mL, and the solvent is water; soak the composite powder in the aqueous solution of 3,4-dihydroxyphenylpropionic acid to obtain a mixture, wherein the ratio of the composite powder soaked in the aqueous solution of 3,4-dihydroxyphenylpropionic acid is 1 g: 40 mL; place the mixture in a vacuum chamber, evacuate to 0.01 atmospheres, and maintain the pressure for 2 hours. Under negative pressure conditions, on the one hand, the solution and powder surface can be fully contacted, and on the other hand, the oxygen content can be reduced, thus reducing the oxygen content of the reactants. After the pressure holding period, the mixture was removed, and the solid and liquid phases were separated. The solid phase was washed three times with ethanol, dried at 100°C for 1 hour, and then soaked in ethanol. The ratio of the amount of the dried solid phase soaked in ethanol was 1 g: 50 mL. The mixture was stirred and dispersed for 30 minutes to obtain a dispersion. Then, hexadecylamine was added, and the mixture was stirred for 10 minutes to mix. Triethylamine was then added. The ratio of the amount of hexadecylamine and triethylamine added to the mass of the dried solid phase in ethanol was 1 g: 1.1 g: 3 g. After the addition, the mixture was heated in a water bath to 60°C and kept at that temperature for 15 hours. After the temperature was maintained, the solid and liquid phases were separated. The solid phase was washed three times with ethanol and dried at 100°C for 1 hour to obtain the filler powder of this comparative example.

[0031] The coating layer is prepared as follows: the epoxy resin is heated to 80°C and stirred for 2 minutes to reduce its viscosity. The temperature is then raised to 120°C and kept at that temperature. The filler powder and aliphatic agent are added to the solvent and stirred for 2 hours to disperse them. After dispersion, the mixture is poured into the epoxy resin kept at 120°C and stirred for 30 minutes to mix evenly. The curing agent is then added and stirred for 5 minutes to mix evenly. The mixture is then coated onto the surface of a test 316 stainless steel plate treated according to standard GB1765-1979 (1989), cured at room temperature for 30 minutes, and then heated to 100°C and dried for 20 minutes to obtain the coating layer of this comparative example.

[0032] Example 5

[0033] The impact resistance of the coatings prepared by the methods described in the above embodiments and comparative examples was tested using a QCJ type paint film impact tester according to the requirements of standard GB / T 1732-2020. The results are shown in Table 1.

[0034] Table 1

[0035] As shown in Table 1, the coating layer prepared by the method described in this invention exhibits good strength and excellent impact resistance. When applied to the inner wall of a single-screw pump, it performs well even in applications with high impact forces, improving the pump's durability. This invention first prepares a composite powder as the matrix powder for the filler. Then, 3,4-dihydroxyphenylpropionic acid is used to modify the surface of the matrix powder, modifying it with catechol groups. Next, a Michael addition reaction is performed between the amino groups of hexadecylamine and triethylamine and the catechol groups to improve the powder's hydrophobicity. Simultaneously, this improves the bonding force between the powder and the resin matrix, increases interfacial adhesion strength, increases coating density, and reduces interfacial defects, thereby improving the coating's strength. Furthermore, the improved interphase bonding allows for effective stress transfer between the components of the composite coating, thus enhancing its mechanical properties. Finally, gallic acid treatment of the powder improves the filler's dispersibility in the resin matrix, reduces agglomeration, and further improves the overall impact resistance of the coating.

[0036] The technical solutions provided by the present invention have been described in detail above. For those skilled in the art, there will be changes in specific implementation methods and application scope based on the ideas of the embodiments of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A coating for the inner wall of an impact-resistant single-screw pump, characterized in that, The raw materials include epoxy resin, filler powder, an alkylating agent, a curing agent, and a solvent. The preparation steps of the filler powder include: (1) Mix acetic acid, ethanol and deionized water evenly in a reaction vessel, then add tetraethyl silicate and cerium nitrate hexahydrate to the reaction vessel, mix well after adding, and then add tetrabutyl titanate; then seal the reaction vessel, heat it with hydrothermal heat, cool it to room temperature after the heat preservation is completed, open the reaction vessel, separate the solid and liquid, wash the solid phase, dry it, and obtain composite powder. (2) Prepare an aqueous solution of 3,4-dihydroxyphenylpropionic acid, immerse the composite powder in the aqueous solution of 3,4-dihydroxyphenylpropionic acid to obtain a mixture, place the mixture in a vacuum chamber, vacuum it, maintain pressure, remove the mixture after the pressure is maintained, separate the solid and liquid, wash the solid phase, dry it, immerse it in ethanol after drying, stir and disperse it to obtain a dispersion, then add n-hexadecylamine, stir and mix it after adding the material, then add triethylamine, heat it in a water bath and keep it warm after adding the material, separate the solid and liquid after the heat is maintained, wash the solid phase, dry it to obtain modified particles; (3) Gallic acid was added to N,N-dimethylformamide and stirred until fully dissolved. Then, the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine were added to the solution. After the addition was completed, the mixture was kept warm in a water bath and stirred. After stirring, the solid and liquid were separated, the solid phase was washed and dried to obtain the filler powder.

2. The impact-resistant coating for the inner wall of a single screw pump according to claim 1, characterized in that, The coating layer is prepared by heating and keeping the epoxy resin at a certain temperature to reduce its viscosity, then adding the filler powder and aliphatic agent to the solvent and stirring to disperse them. After dispersion, the mixture is poured into the epoxy resin at a certain temperature and stirred to mix evenly. Then, the curing agent is added and stirred evenly. The mixture is then coated on the inner wall surface of a single screw pump, cured at room temperature, and then heated and dried to obtain the coating layer.

3. The impact-resistant coating for the inner wall of a single screw pump according to claim 1 or 2, characterized in that, The azo agent is γ-aminopropyltriethoxysilane, the curing agent is T-31 curing agent, and the solvent is acetone.

4. The impact-resistant coating for the inner wall of a single screw pump according to claim 1 or 2, characterized in that, The raw materials are as follows by weight: 100 parts epoxy resin, 3-5 parts filler powder, 2-3 parts azo agent, 20-25 parts curing agent, and 28-30 parts solvent.

5. The impact-resistant coating for the inner wall of a single screw pump according to claim 2, characterized in that, The epoxy resin is heated to 80°C to reduce its viscosity, stirred for 2-3 minutes, and then heated to 120°C and kept warm.

6. The impact-resistant coating for the inner wall of a single screw pump according to claim 1, characterized in that, In step (1), the ratio of acetic acid, ethanol, deionized water, tetraethyl silicate, cerium nitrate hexahydrate, and tetrabutyl titanate used is acetic acid: ethanol: deionized water: tetraethyl silicate: cerium nitrate hexahydrate: tetrabutyl titanate = 4-5 mL: 50 mL: 20-25 mL: 0.3-0.4 g: 0.01-0.02 g: 2.5-3 g; the heating hydrothermal insulation temperature is 160-170℃, and the insulation time is 10-15 h.

7. The impact-resistant coating for the inner wall of a single screw pump according to claim 1, characterized in that, In step (2), the concentration of 3,4-dihydroxyphenylpropionic acid in the aqueous solution of 3,4-dihydroxyphenylpropionic acid is 3-4 mg / mL, and the solvent is water; the ratio of the amount of composite powder soaked in the aqueous solution of 3,4-dihydroxyphenylpropionic acid is 1 g of composite powder to 30-50 mL of aqueous solution of 3,4-dihydroxyphenylpropionic acid.

8. The impact-resistant coating for the inner wall of a single screw pump according to claim 1, characterized in that, In step (2), the ratio of the amount of the dried solid phase soaked in ethanol is solid phase: ethanol = 1g: 50-100mL, and the ratio of the amount of hexadecylamine and triethylamine added to the mass of the dried solid phase added to ethanol is solid phase: hexadecylamine: triethylamine = 1g: 1-1.2g: 2-3g; after adding the materials, heat in a water bath to 55-60℃ and keep warm for 15-20h.

9. The impact-resistant coating for the inner wall of a single screw pump according to claim 1, characterized in that, In step (3), the ratio of gallic acid to N,N-dimethylformamide is gallic acid:N,N-dimethylformamide = 8-10 g: 100 mL. The ratio of the amount of the modified particles, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 4-dimethylaminopyridine added to the solution to the amount of gallic acid is gallic acid:modified particles:1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride:4-dimethylaminopyridine = 8-10 g:3-4 g:10-12 g:1.2-1.4 g. The solution is heated in a water bath to 55-60°C and stirred for at least 45 hours.

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