A high wear-resistant thermosetting plastic powder coating and preparation method thereof

Abstract

The invention discloses a highly wear-resistant thermosetting plastic powder coating and a preparation method thereof. The plastic powder coating comprises the following raw materials in parts by weight: 220-250 parts of epoxy resin E-12, 150-180 parts of modified filler, 40-50 parts of tetrakis(3-mercaptopropionic acid) pentaerythritol ester, 2-6 parts of 4-dimethylaminopyridine, 1-5 parts of 2-isopropylthioxanthone, and 55-60 parts of 4,4'-diaminodiphenylmethane. During the spraying and curing process of the plastic powder coating, under the action of 4-dimethylaminopyridine, some of the thiol groups on the tetrakis(3-mercaptopropionic acid) pentaerythritol ester react with the epoxy groups on the epoxy resin E-21, and the remaining epoxy groups react with the 4,4'-diaminodiphenylmethane. After curing is completed, the thiol groups on the side chains of the epoxy resin curing segments are grafted to the double bonds on the surface of the modified filler under the influence of light, thereby further cross-linking between the molecules, thereby enhancing the wear resistance of the coating film.

Description

Technical Field

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

[0002] With the continuous advancement of industrial technology and increasing demand for product quality, the coatings industry has undergone a transition from traditional solvent-based coatings to environmentally friendly, efficient, and high-performance coatings. As a key branch of the coatings industry, thermosetting plastic powder coatings have gradually become the mainstream of the market due to their environmental, energy-saving, and high-efficiency advantages. Epoxy thermosetting plastic powder coatings use epoxy resin as the primary film-forming substance and are cured by heat to form a hard, durable coating. Epoxy resin has excellent adhesion, chemical resistance, and mechanical properties, but its wear resistance is limited. In highly abrasive environments, the material's service life and performance still need to be further improved. Summary of the Invention

[0003] The purpose of the present invention is to provide a highly wear-resistant thermosetting plastic powder coating and a preparation method thereof, which solves the problem of poor wear resistance of epoxy thermosetting plastic powder coatings at the current stage.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A method for preparing a highly wear-resistant thermosetting plastic powder coating comprises the following steps:

[0006] Step A1: Trimethylenedialdehyde, 3-amino-1,2-propylene glycol, and methanol are uniformly mixed and refluxed at a speed of 60-80 r / min and a temperature of 65-70°C for 2-3 hours to obtain Intermediate 1. 4-Formylphenylboronic acid, Intermediate 1, anhydrous magnesium sulfate, and DMF are uniformly mixed and reacted at a speed of 200-300 r / min and a temperature of 20-25°C for 20-25 hours to obtain Intermediate 2;

[0007] Step A2: Octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, deionized water, and dimethyl sulfoxide were mixed, nitrogen was introduced, and the mixture was reacted at a speed of 120-150 r / min and a temperature of 90-95°C for 10-12 hours to obtain a diamine-terminated polysiloxane.

[0008] Step A3: The diamine-terminated polysiloxane, the precursor, chloroplatinic acid, and DMF were mixed uniformly, nitrogen was introduced, and the reaction was carried out at a speed of 200-300 r / min and a temperature of 80-85°C for 6-8 hours to obtain a pretreated precursor. The pretreated precursor, the intermediate 2, and tetrahydrofuran were mixed uniformly, and the mixture was refluxed at a speed of 120-150 r / min and a temperature of 75-80°C for 3-5 hours to obtain a modified filler;

[0009] Step A4: Epoxy resin E-12, modified filler, pentaerythritol tetrakis(3-mercaptopropionate), 4-dimethylaminopyridine, 2-isopropylthioxanthone and 4,4'-diaminodiphenylmethane are added to a twin-screw extruder. Under the conditions of a zone 1 temperature of 90-95°C, a zone 2 temperature of 90-100°C, a zone 3 temperature of 100-105°C and a zone 4 temperature of 100-105°C, the mixture is extruded, cooled and crushed to obtain a highly wear-resistant thermosetting plastic powder coating.

[0010] Furthermore, the molar ratio of trimesaldehyde and 3-amino-1,2-propylene glycol in step A1 is 1:3, and the molar ratio of 4-formylphenylboronic acid, intermediate 1 and anhydrous magnesium sulfate is 3:1:2.4.

[0011] Furthermore, the usage ratio of octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, and deionized water in step A2 is 2 mol:0.4 mol:2 mol:3 mol:5 L.

[0012] Furthermore, the mass ratio of the diamine-terminated polysiloxane and the precursor in step A3 is 5:1, the amount of chloroplatinic acid used is 1‰ of the mass of the diamine-terminated polysiloxane, and the mass ratio of the pretreated precursor and intermediate 2 is 6:1.

[0013] Furthermore, the weight ratio of the epoxy resin E-12, modified filler, pentaerythritol tetrakis(3-mercaptopropionate), 4-dimethylaminopyridine, 2-isopropylthioxanthone and 4,4'-diaminodiphenylmethane described in step A4 is 220-250:150-180:40-50:2-6:1-5:55-60.

[0014] Furthermore, the precursor is prepared by the following steps:

[0015] Step B1: Hexagonal boron nitride and sodium hydroxide solution are mixed, ultrasonically treated for 1-1.5 hours at a frequency of 20-30 kHz and a temperature of 20-25° C., and then heated to 120-125° C. and refluxed for 20-25 hours to obtain hydroxylated hexagonal boron nitride. The hydroxylated hexagonal boron nitride is dispersed in ethanol, stirred at a speed of 300-500 r / min and a temperature of 70-80° C., and 3-methacryloyloxypropyltrimethoxysilane and deionized water are added, and the mixture is reacted for 3-5 hours to obtain modified hexagonal boron nitride.

[0016] Step B2: Methyltrimethoxysilane, isopropyl alcohol, deionized water and sodium hydroxide are mixed, reacted at a speed of 120-150 r / min and a temperature of 80-85° C. for 2-3 hours, then cooled to 20-25° C. and reacted for 10-12 hours to obtain sodium octamethylcyclotetrasiloxane tetrasiloxide. Sodium octamethylcyclotetrasiloxane tetrasiloxide, triethylamine, methyldichlorosilane and tetrahydrofuran are mixed, nitrogen is introduced, and the mixture is reacted at a speed of 200-300 r / min and a temperature of 0-3° C. for 3-5 hours. The mixture is then heated to 20-25° C. and reacted for 20-25 hours to obtain dihydrogen cage-type silsesquioxane;

[0017] Step B3: uniformly mix the modified hexagonal boron nitride, dihydrogen cage silsesquioxane, chloroplatinic acid and DMF, introduce nitrogen protection, and react at a speed of 500-600 r / min and a temperature of 80-85° C. for 4-6 hours to obtain a precursor.

[0018] Furthermore, the amount ratio of hexagonal boron nitride and sodium hydroxide solution in step B1 is 1g:100mL, the concentration of sodium hydroxide solution is 5mol / L, and the amount of 3-methacryloxypropyltrimethoxysilane is 1% of the mass of hydroxylated hexagonal boron nitride.

[0019] Furthermore, the amount ratio of methyltrimethoxysilane, isopropyl alcohol, deionized water and sodium hydroxide described in step B2 is 30mmol:30mL:1mL:20mmol, and the amount ratio of sodium octamethylcyclotetrasiloxane tetrasiloxide, triethylamine, methyldichlorosilane and tetrahydrofuran is 12g:4.5mL:3.5g:20mL.

[0020] Furthermore, the molar ratio of the double bond on the modified hexagonal boron nitride and the dihydrogen cage silsesquioxane in step B3 is 1:1, and the amount of chloroplatinic acid used is 1‰ of the mass of the dihydrogen cage silsesquioxane.

[0021] Beneficial effects of the present invention: A highly wear-resistant thermosetting plastic powder coating prepared by the present invention comprises the following raw materials: epoxy resin E-12, modified filler, pentaerythritol tetrakis(3-mercaptopropionic acid), 4-dimethylaminopyridine and 4,4'-diaminodiphenylmethane, wherein the modified filler is made of trimesaldehyde and 3-amino-1,2-propylene glycol, so that the aldehyde group on the trimesaldehyde reacts with the amino group on the 3-amino-1,2-propylene glycol to form a carbon-nitrogen double bond to prepare an intermediate 1, and the intermediate 1 is reacted with 4-formylphenylboronic acid so that the propylene glycol on the intermediate 1 reacts with the 4-formylphenylboronic acid. The boronic acid group on the phenylboronic acid is reacted to obtain intermediate 2, the octamethylcyclotetrasiloxane is ring-opened, and the mixture is hydrolyzed and condensed with methacryloxypropylmethyldiethoxysilane, and then capped with 1,3-bis(aminopropyl)tetramethyldisiloxane to obtain diamine-terminated polysiloxane, the diamine-terminated polysiloxane is reacted with a precursor to react the double bond of the diamine-terminated polysiloxane side chain with the silicon-hydrogen bond on the surface of the precursor to obtain a pretreated precursor, the pretreated precursor is reacted with intermediate 2 to react the amino group on the surface of the pretreated precursor with the aldehyde group on the intermediate 2 to form a carbon-nitrogen double bond, and the modified filler is obtained.

[0022] The precursor is prepared by treating hexagonal boron nitride as a raw material with a sodium hydroxide solution to obtain hydroxylated hexagonal boron nitride, treating the hydroxylated hexagonal boron nitride with 3-methacryloyloxypropyltrimethoxysilane to graft double bonds on the surface, hydrolyzing and condensing methyltrimethoxysilane to form sodium octamethylcyclotetrasiloxane tetrasilanolate, reacting the sodium silanolate on the sodium octamethylcyclotetrasiloxane tetrasilanolate with methyldichlorosilane to react with the chlorine atom site on the methyldichlorosilane to obtain dihydrogen cage silsesquioxane, reacting the modified hexagonal boron nitride with the dihydrogen cage silsesquioxane to react the double bond on the modified hexagonal boron nitride with the Si-H bond on the dihydrogen cage silsesquioxane to obtain the precursor.

[0023] During the spray curing process of the plastic powder coating, some of the thiol groups on pentaerythritol tetrakis(3-mercaptopropionate) react with the epoxy groups on the epoxy resin E-21 under the action of 4-dimethylaminopyridine, and the remaining epoxy groups react with 4,4'-diaminodiphenylmethane. After curing, the thiol groups on the side chains of the epoxy resin curing chain segments are grafted to the double bonds on the surface of the modified filler under the influence of light, resulting in further cross-linking between the molecules, thereby enhancing the wear resistance of the coating. At the same time, the surface of the modified filler is coated with an organosilicon polymer, which contains imine and borate structures. The two are dynamically cross-linked structures. When the coating is subjected to external forces, the two structures break, thereby reducing the external forces. The internal cage-type silsesquioxane core is an inorganic framework composed of Si-O-Si bonds, forming a core-shell structure with the external organosilicon polymer. When squeezed, the cage-type silsesquioxane causes the internal hexagonal boron nitride to slide, thereby offsetting the external forces, giving the plastic powder coating excellent wear resistance. DETAILED DESCRIPTION

[0024] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0025] Example 1: A method for preparing a highly wear-resistant thermosetting plastic powder coating, comprising the following steps:

[0026] Step A1: Trimethylenedialdehyde, 3-amino-1,2-propanediol, and methanol were mixed uniformly, and refluxed at 60 r / min and 65°C for 2 h to obtain Intermediate 1. 4-Formylphenylboronic acid, Intermediate 1, anhydrous magnesium sulfate, and DMF were mixed uniformly, and reacted at 200 r / min and 20°C for 20 h to obtain Intermediate 2.

[0027] Step A2: Octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, deionized water, and dimethyl sulfoxide were mixed, nitrogen was introduced, and the mixture was reacted at a speed of 120 r / min and a temperature of 90°C for 10 hours to obtain a diamine-terminated polysiloxane.

[0028] Step A3: The diamine-terminated polysiloxane, the precursor, chloroplatinic acid, and DMF were mixed uniformly, and nitrogen was introduced for protection. The mixture was reacted at a speed of 200 r / min and a temperature of 80°C for 6 hours to obtain a pretreated precursor. The pretreated precursor, the intermediate 2, and tetrahydrofuran were mixed uniformly, and the mixture was refluxed at a speed of 120 r / min and a temperature of 75°C for 3 hours to obtain a modified filler.

[0029] Step A4: Weigh the following raw materials in parts by weight: 220 parts of epoxy resin E-12, 150 parts of modified filler, 40 parts of pentaerythritol tetrakis(3-mercaptopropionate), 2 parts of 4-dimethylaminopyridine, 1 part of 2-isopropylthioxanthone and 55 parts of 4,4'-diaminodiphenylmethane, add the raw materials into a twin-screw extruder, and extrude, cool and crush under the conditions of a zone 1 temperature of 90°C, a zone 2 temperature of 90°C, a zone 3 temperature of 100°C and a zone 4 temperature of 100°C to obtain a highly wear-resistant thermosetting plastic powder coating.

[0030] The molar ratio of trimesaldehyde to 3-amino-1,2-propylene glycol in step A1 is 1:3, and the molar ratio of 4-formylphenylboronic acid, intermediate 1 and anhydrous magnesium sulfate is 3:1:2.4.

[0031] The amount ratio of octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, and deionized water described in step A2 is 2 mol:0.4 mol:2 mol:3 mol:5 L.

[0032] The mass ratio of the diamine-terminated polysiloxane and the precursor described in step A3 is 5:1, the amount of chloroplatinic acid used is 1‰ of the mass of the diamine-terminated polysiloxane, and the mass ratio of the pretreated precursor and intermediate 2 is 6:1.

[0033] The precursor is prepared by the following steps:

[0034] Step B1: Hexagonal boron nitride and sodium hydroxide solution were mixed, ultrasonically treated at a frequency of 20 kHz and a temperature of 20°C for 1 hour, then heated to 120°C and refluxed for 20 hours to obtain hydroxylated hexagonal boron nitride. The hydroxylated hexagonal boron nitride was dispersed in ethanol, stirred at a speed of 300 r / min and a temperature of 70°C, and 3-methacryloyloxypropyltrimethoxysilane and deionized water were added, and the mixture was reacted for 3 hours to obtain modified hexagonal boron nitride.

[0035] Step B2: Methyltrimethoxysilane, isopropanol, deionized water and sodium hydroxide were mixed, reacted at a speed of 120 r / min and a temperature of 80° C. for 2 h, then cooled to 20° C. and continued to react for 10 h to obtain sodium octamethylcyclotetrasiloxane tetrasiloxide. Sodium octamethylcyclotetrasiloxane tetrasiloxide, triethylamine, methyldichlorosilane and tetrahydrofuran were mixed, nitrogen was introduced, and the mixture was reacted at a speed of 200 r / min and a temperature of 0° C. for 3 h, then heated to 20° C. and reacted for 20 h to obtain dihydrogen cage-type silsesquioxane;

[0036] Step B3: Modified hexagonal boron nitride, dihydrogen cage silsesquioxane, chloroplatinic acid and DMF were mixed evenly, nitrogen was introduced for protection, and the reaction was carried out at a speed of 500 r / min and a temperature of 80° C. for 4 hours to obtain a precursor.

[0037] The amount ratio of hexagonal boron nitride and sodium hydroxide solution in step B1 is 1g:100mL, the concentration of sodium hydroxide solution is 5mol / L, and the amount of 3-methacryloxypropyltrimethoxysilane is 1% of the mass of hydroxylated hexagonal boron nitride.

[0038] The amount ratio of methyltrimethoxysilane, isopropyl alcohol, deionized water and sodium hydroxide described in step B2 is 30mmol:30mL:1mL:20mmol, and the amount ratio of sodium octamethylcyclotetrasiloxane tetrasiloxide, triethylamine, methyldichlorosilane and tetrahydrofuran is 12g:4.5mL:3.5g:20mL.

[0039] The molar ratio of the double bond on the modified hexagonal boron nitride and the dihydrogen cage silsesquioxane in step B3 is 1:1, and the amount of chloroplatinic acid used is 1‰ of the mass of the dihydrogen cage silsesquioxane.

[0040] Example 2: A method for preparing a highly wear-resistant thermosetting plastic powder coating, comprising the following steps:

[0041] Step A1: Trimethylenedialdehyde, 3-amino-1,2-propanediol, and methanol were mixed uniformly, and refluxed at a speed of 60 r / min and a temperature of 70°C for 2 h to obtain intermediate 1. 4-Formylphenylboronic acid, intermediate 1, anhydrous magnesium sulfate, and DMF were mixed uniformly, and reacted at a speed of 200 r / min and a temperature of 25°C for 20 h to obtain intermediate 2;

[0042] Step A2: Octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, deionized water, and dimethyl sulfoxide were mixed, nitrogen was introduced, and the mixture was reacted at a speed of 150 r / min and a temperature of 90°C for 12 hours to obtain a diamine-terminated polysiloxane.

[0043] Step A3: The diamine-terminated polysiloxane, the precursor, chloroplatinic acid, and DMF were mixed uniformly, and nitrogen was introduced to protect the mixture. The mixture was reacted at a speed of 200 r / min and a temperature of 85°C for 7 hours to obtain a pretreated precursor. The pretreated precursor, the intermediate 2, and tetrahydrofuran were mixed uniformly, and the mixture was refluxed at a speed of 120 r / min and a temperature of 80°C for 4 hours to obtain a modified filler.

[0044] Step A4: Weigh the following raw materials in parts by weight: 235 parts of epoxy resin E-12, 165 parts of modified filler, 45 parts of pentaerythritol tetrakis(3-mercaptopropionate), 4 parts of 4-dimethylaminopyridine, 3 parts of 2-isopropylthioxanthone and 58 parts of 4,4'-diaminodiphenylmethane, add the raw materials into a twin-screw extruder, and extrude, cool and crush under the conditions of a zone 1 temperature of 95°C, a zone 2 temperature of 100°C, a zone 3 temperature of 100°C and a zone 4 temperature of 105°C to obtain a highly wear-resistant thermosetting plastic powder coating.

[0045] The molar ratio of trimesaldehyde to 3-amino-1,2-propylene glycol in step A1 is 1:3, and the molar ratio of 4-formylphenylboronic acid, intermediate 1 and anhydrous magnesium sulfate is 3:1:2.4.

[0046] The amount ratio of octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, and deionized water described in step A2 is 2 mol:0.4 mol:2 mol:3 mol:5 L.

[0047] The mass ratio of the diamine-terminated polysiloxane and the precursor described in step A3 is 5:1, the amount of chloroplatinic acid used is 1‰ of the mass of the diamine-terminated polysiloxane, and the mass ratio of the pretreated precursor and intermediate 2 is 6:1.

[0048] The precursor is prepared by the following steps:

[0049] Step B1: Hexagonal boron nitride and sodium hydroxide solution were mixed, ultrasonically treated at a frequency of 25 kHz and a temperature of 20°C for 1.5 hours, then heated to 120°C and refluxed for 25 hours to obtain hydroxylated hexagonal boron nitride. The hydroxylated hexagonal boron nitride was dispersed in ethanol, stirred at a speed of 300 r / min and a temperature of 75°C, and 3-methacryloyloxypropyltrimethoxysilane and deionized water were added, and the mixture was reacted for 4 hours to obtain modified hexagonal boron nitride.

[0050] Step B2: Methyltrimethoxysilane, isopropanol, deionized water and sodium hydroxide were mixed, reacted at a speed of 120 r / min and a temperature of 85° C. for 3 h, then cooled to 20° C. and continued to react for 12 h to obtain sodium octamethylcyclotetrasiloxane tetrasiloxide. Sodium octamethylcyclotetrasiloxane tetrasiloxide, triethylamine, methyldichlorosilane and tetrahydrofuran were mixed, nitrogen was introduced, and the mixture was reacted at a speed of 200 r / min and a temperature of 3° C. for 4 h, then heated to 20° C. and reacted for 25 h to obtain dihydrogen cage-type silsesquioxane;

[0051] Step B3: Modified hexagonal boron nitride, dihydrogen cage silsesquioxane, chloroplatinic acid and DMF were mixed evenly, nitrogen was introduced for protection, and the reaction was carried out at a speed of 500 r / min and a temperature of 85° C. for 5 hours to obtain a precursor.

[0052] The amount ratio of hexagonal boron nitride and sodium hydroxide solution in step B1 is 1g:100mL, the concentration of sodium hydroxide solution is 5mol / L, and the amount of 3-methacryloxypropyltrimethoxysilane is 1% of the mass of hydroxylated hexagonal boron nitride.

[0053] The amount ratio of methyltrimethoxysilane, isopropyl alcohol, deionized water and sodium hydroxide described in step B2 is 30mmol:30mL:1mL:20mmol, and the amount ratio of sodium octamethylcyclotetrasiloxane tetrasiloxide, triethylamine, methyldichlorosilane and tetrahydrofuran is 12g:4.5mL:3.5g:20mL.

[0054] The molar ratio of the double bond on the modified hexagonal boron nitride and the dihydrogen cage silsesquioxane in step B3 is 1:1, and the amount of chloroplatinic acid used is 1‰ of the mass of the dihydrogen cage silsesquioxane.

[0055] Example 3: A method for preparing a highly wear-resistant thermosetting plastic powder coating, comprising the following steps:

[0056] Step A1: Trimethylenedialdehyde, 3-amino-1,2-propylene glycol, and methanol were mixed uniformly, and refluxed at 80 r / min and 70°C for 3 h to obtain Intermediate 1. 4-Formylphenylboronic acid, Intermediate 1, anhydrous magnesium sulfate, and DMF were mixed uniformly, and reacted at 300 r / min and 25°C for 25 h to obtain Intermediate 2.

[0057] Step A2: Octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, deionized water, and dimethyl sulfoxide were mixed, nitrogen was introduced, and the mixture was reacted at a speed of 150 r / min and a temperature of 95°C for 12 hours to obtain a diamine-terminated polysiloxane.

[0058] Step A3: The diamine-terminated polysiloxane, the precursor, chloroplatinic acid, and DMF were mixed uniformly, and nitrogen was introduced to protect the mixture. The mixture was reacted at a speed of 300 r / min and a temperature of 85°C for 8 hours to obtain a pretreated precursor. The pretreated precursor, the intermediate 2, and tetrahydrofuran were mixed uniformly, and the mixture was refluxed at a speed of 150 r / min and a temperature of 80°C for 5 hours to obtain a modified filler.

[0059] Step A4: Weigh the following raw materials in parts by weight: 250 parts of epoxy resin E-12, 180 parts of modified filler, 50 parts of pentaerythritol tetrakis(3-mercaptopropionate), 6 parts of 4-dimethylaminopyridine, 5 parts of 2-isopropylthioxanthone and 60 parts of 4,4'-diaminodiphenylmethane, add the raw materials into a twin-screw extruder, and extrude, cool and crush under the conditions of a zone 1 temperature of 95°C, a zone 2 temperature of 100°C, a zone 3 temperature of 105°C and a zone 4 temperature of 105°C to obtain a highly wear-resistant thermosetting plastic powder coating.

[0060] The molar ratio of trimesaldehyde to 3-amino-1,2-propylene glycol in step A1 is 1:3, and the molar ratio of 4-formylphenylboronic acid, intermediate 1 and anhydrous magnesium sulfate is 3:1:2.4.

[0061] The amount ratio of octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, and deionized water described in step A2 is 2 mol:0.4 mol:2 mol:3 mol:5 L.

[0062] The mass ratio of the diamine-terminated polysiloxane and the precursor described in step A3 is 5:1, the amount of chloroplatinic acid used is 1‰ of the mass of the diamine-terminated polysiloxane, and the mass ratio of the pretreated precursor and intermediate 2 is 6:1.

[0063] The precursor is prepared by the following steps:

[0064] Step B1: Hexagonal boron nitride and sodium hydroxide solution were mixed, ultrasonically treated at a frequency of 30 kHz and a temperature of 25°C for 1.5 hours, then heated to 125°C and refluxed for 25 hours to obtain hydroxylated hexagonal boron nitride. The hydroxylated hexagonal boron nitride was dispersed in ethanol, stirred at a speed of 500 r / min and a temperature of 80°C, and 3-methacryloyloxypropyltrimethoxysilane and deionized water were added, and the mixture was reacted for 5 hours to obtain modified hexagonal boron nitride.

[0065] Step B2: Methyltrimethoxysilane, isopropyl alcohol, deionized water and sodium hydroxide were mixed, reacted at a speed of 150 r / min and a temperature of 85° C. for 3 hours, then cooled to 25° C. and continued to react for 12 hours to obtain octamethylcyclotetrasiloxane tetrasilanolate sodium. Octamethylcyclotetrasiloxane tetrasilanolate sodium, triethylamine, methyldichlorosilane and tetrahydrofuran were mixed, nitrogen was introduced, and the reaction was carried out at a speed of 300 r / min and a temperature of 3° C. for 5 hours. The temperature was then raised to 25° C. and the reaction was carried out for 25 hours to obtain dihydrogen cage-type silsesquioxane;

[0066] Step B3: Modified hexagonal boron nitride, dihydrogen cage silsesquioxane, chloroplatinic acid and DMF were mixed evenly, nitrogen was introduced for protection, and the reaction was carried out at a speed of 600 r / min and a temperature of 85° C. for 6 hours to obtain a precursor.

[0067] The amount ratio of hexagonal boron nitride and sodium hydroxide solution in step B1 is 1g:100mL, the concentration of sodium hydroxide solution is 5mol / L, and the amount of 3-methacryloxypropyltrimethoxysilane is 1% of the mass of hydroxylated hexagonal boron nitride.

[0068] The amount ratio of methyltrimethoxysilane, isopropyl alcohol, deionized water and sodium hydroxide described in step B2 is 30mmol:30mL:1mL:20mmol, and the amount ratio of sodium octamethylcyclotetrasiloxane tetrasiloxide, triethylamine, methyldichlorosilane and tetrahydrofuran is 12g:4.5mL:3.5g:20mL.

[0069] The molar ratio of the double bond on the modified hexagonal boron nitride and the dihydrogen cage silsesquioxane in step B3 is 1:1, and the amount of chloroplatinic acid used is 1‰ of the mass of the dihydrogen cage silsesquioxane.

[0070] Comparative Example 1: Compared with Example 1, this comparative example did not add pentaerythritol tetrakis(3-mercaptopropionate), and the remaining steps were the same.

[0071] Comparative Example 2: Compared with Example 1, this comparative example uses trimesic acid aldehyde instead of intermediate 2, and the remaining steps are the same.

[0072] Comparative Example 3: Compared with Example 1, this comparative example uses dimethylsilane instead of dihydrogen cage silsesquioxane, and the remaining steps are the same.

[0073] The powder coatings prepared in Examples 1-3 and Comparative Examples 1-3 were sprayed onto a standard test plate by high-voltage electrostatic spraying. The spray coating thickness was about 100 μm, the curing temperature was 150°C, the curing time was 5 min, and then irradiated with 365 nm ultraviolet light for 8 s to prepare the test sample. A CS-10 grinding wheel with a load of 200 g was tested at a speed of 60 r / min for 1 h, and the weight loss of the samples after wear of each embodiment and comparative example was recorded. The paint film hardness was tested in accordance with the standard of GB / T6739-2022. The test results are shown in Table 1 below.

[0074] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Weight loss mg 28 25 24 39 51 63 Paint film hardness 4H 4H 4H 3H 3H 2H

[0075] It can be seen from the above table that this application has a very good wear-resistant effect.

[0076] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a highly wear-resistant thermosetting plastic powder coating, characterized in that: The specific steps include: Step A1: Trimethylenedialdehyde, 3-amino-1,2-propanediol and methanol are mixed and refluxed to obtain Intermediate 1, and 4-formylphenylboronic acid, Intermediate 1, anhydrous magnesium sulfate and DMF are mixed and reacted to obtain Intermediate 2; Step A2: Octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, deionized water, and dimethyl sulfoxide were mixed, and nitrogen was introduced to react to obtain a diamine-terminated polysiloxane. Step A3: uniformly mixing the diamine-terminated polysiloxane, the precursor, chloroplatinic acid, and DMF, introducing nitrogen protection, and reacting to obtain a pretreated precursor. The pretreated precursor, the intermediate 2, and tetrahydrofuran are mixed and refluxed to react to obtain a modified filler. Step A4: adding epoxy resin E-12, modified filler, pentaerythritol tetrakis(3-mercaptopropionate), 4-dimethylaminopyridine, 2-isopropylthioxanthone, and 4,4'-diaminodiphenylmethane into a twin-screw extruder, extruding, cooling, and crushing to obtain a highly wear-resistant thermosetting plastic powder coating; The weight ratio of the epoxy resin E-12, modified filler, pentaerythritol tetrakis(3-mercaptopropionate), 4-dimethylaminopyridine, 2-isopropylthioxanthone, and 4,4'-diaminodiphenylmethane described in step A4 is 220-250:150-180:40-50:2-6:1-5:55-60; The precursor is prepared by the following steps: Step B1: Hexagonal boron nitride and a sodium hydroxide solution are mixed, ultrasonically treated, and then heated and refluxed to obtain hydroxylated hexagonal boron nitride. The hydroxylated hexagonal boron nitride is dispersed in ethanol, stirred, and 3-methacryloxypropyltrimethoxysilane and deionized water are added to react to obtain modified hexagonal boron nitride. Step B2: Methyltrimethoxysilane, isopropyl alcohol, deionized water, and sodium hydroxide are mixed to react to obtain sodium octamethylcyclotetrasiloxane tetrasiloxide, and sodium octamethylcyclotetrasiloxane tetrasiloxide, triethylamine, methyldichlorosilane, and tetrahydrofuran are mixed, and nitrogen is introduced to react to obtain dihydrogen cage-type silsesquioxane; Step B3: uniformly mix the modified hexagonal boron nitride, dihydrogen cage silsesquioxane, chloroplatinic acid and DMF, introduce nitrogen protection, and react to obtain a precursor.

2. The method for preparing a highly wear-resistant thermosetting plastic powder coating according to claim 1, wherein: The molar ratio of trimesaldehyde to 3-amino-1,2-propylene glycol in step A1 is 1:3, and the molar ratio of 4-formylphenylboronic acid, intermediate 1 and anhydrous magnesium sulfate is 3:1:2.

4.

3. The method for preparing a highly wear-resistant thermosetting plastic powder coating according to claim 1, wherein: The amount ratio of octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, and deionized water described in step A2 is 2 mol:0.4 mol:2 mol:3 mol:5 L.

4. The method for preparing a highly wear-resistant thermosetting plastic powder coating according to claim 1, wherein: The mass ratio of the diamine-terminated polysiloxane to the precursor in step A3 is 5:1, and the mass ratio of the pretreated precursor to the intermediate 2 is 6:

1.

5. The method for preparing a highly wear-resistant thermosetting plastic powder coating according to claim 1, wherein: The amount ratio of hexagonal boron nitride and sodium hydroxide solution in step B1 is 1g:100mL, and the amount of 3-methacryloxypropyltrimethoxysilane is 1% of the mass of hydroxylated hexagonal boron nitride.

6. The method for preparing a highly wear-resistant thermosetting plastic powder coating according to claim 1, characterized in that: The amount ratio of methyltrimethoxysilane, isopropyl alcohol, deionized water and sodium hydroxide described in step B2 is 30mmol:30mL:1mL:20mmol, and the amount ratio of sodium octamethylcyclotetrasiloxane tetrasiloxide, triethylamine, methyldichlorosilane and tetrahydrofuran is 12g:4.5mL:3.5g:20mL.

7. The method for preparing a highly wear-resistant thermosetting plastic powder coating according to claim 1, characterized in that: The molar ratio of the double bond on the modified hexagonal boron nitride and the dihydrogen cage silsesquioxane in step B3 is 1:

1.

8. A highly wear-resistant thermosetting plastic powder coating, characterized by: Prepared according to any one of claims 1 to 7.