High-wear-resistance thermosetting molding powder coating and preparation method thereof

Abstract

The invention discloses a high-wear-resistance thermosetting molding powder coating and a preparation method thereof, and the molding powder coating is prepared from the following raw materials in parts by weight: 220 to 250 parts of epoxy resin E-12, 150 to 180 parts of modified filler, 40 to 50 parts of tetrakis (3-mercaptopropionic acid) pentaerythritol ester, 2 to 6 parts of 4-dimethylaminopyridine, 1 to 5 parts of 2-isopropylthioxanthone and 55 to 60 parts of 4, 4 '-diphenyl-1, 3-pentanediol monoisobutyrate. In the spraying and curing process of the molding powder coating, part of sulfydryl on the tetra (3-mercaptopropionic acid) pentaerythritol ester can react with epoxy groups on the epoxy resin E-21 under the action of 4-dimethylaminopyridine, the remaining epoxy groups can react with the 4, 4 '-diaminodiphenylmethane, and the molding powder coating is influenced by illumination after curing. Sulfydryl of a side chain of an epoxy resin curing chain segment is grafted with double bonds on the surface of the modified filler, so that molecules are further crosslinked, and the wear-resistant effect of a coating film is enhanced.

Description

Technical Field

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

[0002] With the continuous progress of industrial technology and the improvement of people's requirements for product quality, the coating industry has experienced a transformation from traditional solvent-based coatings to environmentally friendly, efficient, and high-performance coatings. Thermosetting powder coatings, as an important branch of the coating industry, have gradually become the mainstream of the market due to their environmental friendliness, energy conservation, and high efficiency. Epoxy thermosetting powder coatings use epoxy resin as the main film-forming substance and form a hard and durable coating through heat curing. Epoxy resin has excellent adhesion, chemical corrosion resistance, and mechanical properties, but its wear resistance is limited. In high-wear environments, the service life and performance of the material 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 powder coating and a preparation method thereof, which solves the problem of poor wear resistance of epoxy thermosetting powder coatings at the present stage.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A preparation method of a highly wear-resistant thermosetting powder coating specifically includes the following steps: Step A1: Mix trimellitic triformyl, 3-amino-1,2-propanediol, and methanol evenly, and under the conditions of a rotation speed of 60 - 80 r / min and a temperature of 65 - 70 °C, carry out a reflux reaction for 2 - 3 h to obtain intermediate 1. Mix 4-formylphenylboronic acid, intermediate 1, anhydrous magnesium sulfate, and DMF evenly, and under the conditions of a rotation speed of 200 - 300 r / min and a temperature of 20 - 25 °C, carry out a reaction for 20 - 25 h to obtain intermediate 2; Step A2: Mix octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, deionized water, and dimethyl sulfoxide, introduce nitrogen protection, and under the conditions of a rotation speed of 120 - 150 r / min and a temperature of 90 - 95 °C, carry out a reaction for 10 - 12 h to obtain diamine-terminated polysiloxane; Step A3: Mix diamine-terminated polysiloxane, precursor, chloroplatinic acid, and DMF evenly, introduce nitrogen protection, and under the conditions of a rotation speed of 200 - 300 r / min and a temperature of 80 - 85 °C, carry out a reaction for 6 - 8 h to obtain a pretreated precursor. Mix the pretreated precursor, intermediate 2, and tetrahydrofuran evenly, and under the conditions of a rotation speed of 120 - 150 r / min and a temperature of 75 - 80 °C, carry out a reflux reaction for 3 - 5 h to obtain a modified filler; Step A4: Add epoxy resin E-12, modified filler, pentaerythritol tetrakis(3-mercaptopropionate), 4-dimethylaminopyridine, 2-isopropylthioxanthone, and 4,4'-diaminodiphenylmethane into a twin-screw extruder. Under the conditions that the temperature of zone 1 is 90 - 95 °C, the temperature of zone 2 is 90 - 100 °C, the temperature of zone 3 is 100 - 105 °C, and the temperature of zone 4 is 100 - 105 °C, extrude, cool, and pulverize to obtain a highly wear-resistant thermosetting powder coating.

[0005] Furthermore, the molar ratio of mellitic aldehyde and 3-amino-1,2-propanediol described 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.

[0006] Furthermore, the dosage 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.

[0007] Furthermore, the mass ratio of the diamine-terminated polysiloxane and the precursor described in Step A3 is 5:1, the dosage of chloroplatinic acid is 1‰ of the mass of the diamine-terminated polysiloxane, and the mass ratio of the pretreated precursor and intermediate 2 is 6:1.

[0008] Furthermore, the weight part ratio of 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.

[0009] Furthermore, the precursor is prepared by the following steps: Step B1: Mix hexagonal boron nitride and sodium hydroxide solution. Under the conditions that the frequency is 20 - 30 kHz and the temperature is 20 - 25 °C, after ultrasonic treatment for 1 - 1.5 h, raise the temperature to 120 - 125 °C and carry out reflux treatment for 20 - 25 h to obtain hydroxylated hexagonal boron nitride. Disperse the hydroxylated hexagonal boron nitride in ethanol. Under the conditions that the rotation speed is 300 - 500 r / min and the temperature is 70 - 80 °C, stir and add 3-methacryloxypropyltrimethoxysilane and deionized water, and carry out the reaction for 3 - 5 h to obtain modified hexagonal boron nitride; Step B2: Mix methyltrimethoxysilane, isopropanol, deionized water and sodium hydroxide, and react at a rotation speed of 120 - 150 r / min and a temperature of 80 - 85 °C for 2 - 3 h. Then cool down to 20 - 25 °C and continue to react for 10 - 12 h to obtain sodium octamethylcyclotetrasiloxanetetrasilanol. Mix sodium octamethylcyclotetrasiloxanetetrasilanol, triethylamine, methyldichlorosilane and tetrahydrofuran, introduce nitrogen protection, and react at a rotation speed of 200 - 300 r / min and a temperature of 0 - 3 °C for 3 - 5 h. Then raise the temperature to 20 - 25 °C and react for 20 - 25 h to obtain dihydroxycage-like silsesquioxane; Step B3: Mix the modified hexagonal boron nitride, dihydroxycage-like silsesquioxane, chloroplatinic acid and DMF evenly, introduce nitrogen protection, and react at a rotation speed of 500 - 600 r / min and a temperature of 80 - 85 °C for 4 - 6 h to obtain the precursor.

[0010] Furthermore, the dosage ratio of the hexagonal boron nitride and the sodium hydroxide solution described in Step B1 is 1 g:100 mL, the concentration of the sodium hydroxide solution is 5 mol / L, and the dosage of 3 - methacryloxypropyltrimethoxysilane is 1% of the mass of the hydroxylated hexagonal boron nitride.

[0011] Furthermore, the dosage ratio of the methyltrimethoxysilane, isopropanol, deionized water and sodium hydroxide described in Step B2 is 30 mmol:30 mL:1 mL:20 mmol, and the dosage ratio of the sodium octamethylcyclotetrasiloxanetetrasilanol, triethylamine, methyldichlorosilane and tetrahydrofuran is 12 g:4.5 mL:3.5 g:20 mL.

[0012] Furthermore, the molar ratio of the double bond on the modified hexagonal boron nitride to the dihydroxycage-like silsesquioxane described in Step B3 is 1:1, and the dosage of chloroplatinic acid is 1‰ of the mass of the dihydroxycage-like silsesquioxane.

[0013] Advantages of the present invention: A highly wear-resistant thermosetting powder coating prepared by the present invention comprises the following raw materials: epoxy resin E-12, modified filler, pentaerythritol tetra(3-mercaptopropionate), 4-dimethylaminopyridine, and 4,4'-diaminodiphenylmethane. The modified filler is prepared from trimellitic triformyl and 3-amino-1,2-propanediol, such that the aldehyde group on trimellitic triformyl reacts with the amino group on 3-amino-1,2-propanediol to form a carbon-nitrogen double bond, obtaining intermediate 1. Intermediate 1 is reacted with 4-formylphenylboronic acid, such that the propanediol on intermediate 1 reacts with the boronic acid group on 4-formylphenylboronic acid, obtaining intermediate 2. Octamethylcyclotetrasiloxane is ring-opened, hydrolytically condensed with methacryloxypropylmethyldiethoxysilane, and then terminated with 1,3-bis(aminopropyl)tetramethyldisiloxane to obtain a diamine-terminated polysiloxane. The diamine-terminated polysiloxane is reacted with a precursor, such that the double bond in the side chain of the diamine-terminated polysiloxane reacts with the Si-H bond on the surface of the precursor, obtaining a pretreated precursor. The pretreated precursor is reacted with intermediate 2, such that the amino group on the surface of the pretreated precursor reacts with the aldehyde group on intermediate 2 to form a carbon-nitrogen double bond, obtaining the modified filler.

[0014] The precursor is prepared by treating hexagonal boron nitride with a sodium hydroxide solution to obtain hydroxylated hexagonal boron nitride. The hydroxylated hexagonal boron nitride is treated with 3-methacryloxypropyltrimethoxysilane to graft double bonds on the surface. Methyltrimethoxysilane is hydrolytically condensed to form octamethylcyclotetrasiloxanetetrasodium silanolate. Octamethylcyclotetrasiloxanetetrasodium silanolate is reacted with methyldichlorosilane, such that the sodium silanolate on octamethylcyclotetrasiloxanetetrasodium silanolate reacts with the chlorine atom site on methyldichlorosilane, obtaining dihydridosilsesquioxane. The modified hexagonal boron nitride is reacted with dihydridosilsesquioxane, such that the double bond on the modified hexagonal boron nitride reacts with the Si-H bond on dihydridosilsesquioxane, obtaining the precursor.

[0015] During the spraying and curing process of the powder coating, under the action of 4-dimethylaminopyridine, some of the mercapto groups on pentaerythritol tetra(3-mercaptopropionate) react with the epoxy groups on epoxy resin E-21, and the remaining epoxy groups react with 4,4'-diaminodiphenylmethane. After curing, under the influence of light, the mercapto groups on the side chains of the cured epoxy resin segments graft with the double bonds on the surface of the modified filler, further crosslinking between molecules, thereby enhancing the wear resistance of the coating film. At the same time, the surface of the modified filler is coated with an organosilicon polymer, and there are imine structures and borate ester structures between the organosilicon polymers, which are dynamic crosslinking structures. When the coating film is subjected to external forces, the two structures break, thereby reducing the external forces. Moreover, the internal cage-like silsesquioxane core is an inorganic framework composed of Si-O-Si bonds, forming a core-shell structure with the external organosilicon polymer. When being squeezed, the internal hexagonal boron nitride slides under the action of the cage-like silsesquioxane, further offsetting the external forces, such that the powder coating has good wear resistance. Detailed implementation mode

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0017] Embodiment 1. A preparation method of a highly wear-resistant thermosetting plastic powder coating specifically includes the following steps: Step A1: Mix trimellitic aldehyde, 3-amino-1,2-propanediol and methanol evenly. Under the conditions of a rotation speed of 60 r / min and a temperature of 65 °C, carry out a reflux reaction for 2 h to obtain intermediate 1. Mix 4-formylphenylboronic acid, intermediate 1, anhydrous magnesium sulfate and DMF evenly. Under the conditions of a rotation speed of 200 r / min and a temperature of 20 °C, carry out a reaction for 20 h to obtain intermediate 2; Step A2: Mix octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, deionized water and dimethyl sulfoxide, introduce nitrogen protection. Under the conditions of a rotation speed of 120 r / min and a temperature of 90 °C, carry out a reaction for 10 h to obtain diamine-terminated polysiloxane; Step A3: Mix diamine-terminated polysiloxane, precursor, chloroplatinic acid and DMF evenly, introduce nitrogen protection. Under the conditions of a rotation speed of 200 r / min and a temperature of 80 °C, carry out a reaction for 6 h to obtain a pretreated precursor. Mix the pretreated precursor, intermediate 2 and tetrahydrofuran evenly. Under the conditions of a rotation speed of 120 r / min and a temperature of 75 °C, carry out a reflux reaction for 3 h to obtain a modified filler; 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. Under the conditions that the temperature of zone 1 is 90 °C, the temperature of zone 2 is 90 °C, the temperature of zone 3 is 100 °C, and the temperature of zone 4 is 100 °C, extrude, cool and pulverize to obtain a highly wear-resistant thermosetting plastic powder coating.

[0018] The molar ratio of trimellitic aldehyde and 3-amino-1,2-propanediol described 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.

[0019] The dosage 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.

[0020] The mass ratio of the diamine-terminated polysiloxane and the precursor described in step A3 is 5:1. The dosage of chloroplatinic acid is 1‰ of the mass of the diamine-terminated polysiloxane. The mass ratio of the pretreated precursor and intermediate 2 is 6:1.

[0021] The described precursor is prepared by the following steps: Step B1: Mix hexagonal boron nitride and sodium hydroxide solution, under the conditions of a frequency of 20 kHz and a temperature of 20 °C, after ultrasonic treatment for 1 h, raise the temperature to 120 °C and carry out reflux treatment for 20 h to obtain hydroxylated hexagonal boron nitride. Disperse the hydroxylated hexagonal boron nitride in ethanol, and under the conditions of a rotation speed of 300 r / min and a temperature of 70 °C, stir and add 3-methacryloxypropyltrimethoxysilane and deionized water, and carry out the reaction for 3 h to obtain modified hexagonal boron nitride; Step B2: Mix methyltrimethoxysilane, isopropanol, deionized water and sodium hydroxide, under the conditions of a rotation speed of 120 r / min and a temperature of 80 °C, after the reaction for 2 h, lower the temperature to 20 °C and continue the reaction for 10 h to obtain octamethylcyclotetrasiloxane tetrasodium silanolate. Mix octamethylcyclotetrasiloxane tetrasodium silanolate, triethylamine, methyldichlorosilane and tetrahydrofuran, and pass in nitrogen for protection. Under the conditions of a rotation speed of 200 r / min and a temperature of 0 °C, after the reaction for 3 h, raise the temperature to 20 °C and carry out the reaction for 20 h to obtain dihydroxycage silsesquioxane; Step B3: Mix the modified hexagonal boron nitride, dihydroxycage silsesquioxane, chloroplatinic acid and DMF evenly, pass in nitrogen for protection, and under the conditions of a rotation speed of 500 r / min and a temperature of 80 °C, carry out the reaction for 4 h to obtain the precursor.

[0022] The dosage ratio of the hexagonal boron nitride and the sodium hydroxide solution described in step B1 is 1 g: 100 mL. The concentration of the sodium hydroxide solution is 5 mol / L. The dosage of 3-methacryloxypropyltrimethoxysilane is 1% of the mass of the hydroxylated hexagonal boron nitride.

[0023] The dosage ratio of methyltrimethoxysilane, isopropanol, deionized water and sodium hydroxide described in step B2 is 30 mmol: 30 mL: 1 mL: 20 mmol. The dosage ratio of octamethylcyclotetrasiloxane tetrasodium silanolate, triethylamine, methyldichlorosilane and tetrahydrofuran is 12 g: 4.5 mL: 3.5 g: 20 mL.

[0024] The molar ratio of the double bond on the modified hexagonal boron nitride described in step B3 to the dihydrocage silsesquioxane is 1:1, and the dosage of chloroplatinic acid is 1‰ of the mass of the dihydrocage silsesquioxane.

[0025] Example 2. A preparation method of a highly wear-resistant thermosetting powder coating specifically includes the following steps: Step A1: Mix trimellitic triformyl, 3-amino-1,2-propanediol, and methanol evenly. Under the conditions of a rotation speed of 60 r / min and a temperature of 70 °C, carry out a reflux reaction for 2 h to obtain intermediate 1. Mix 4-formylphenylboronic acid, intermediate 1, anhydrous magnesium sulfate, and DMF evenly. Under the conditions of a rotation speed of 200 r / min and a temperature of 25 °C, carry out a reaction for 20 h to obtain intermediate 2; Step A2: Mix octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, deionized water, and dimethyl sulfoxide, introduce nitrogen protection. Under the conditions of a rotation speed of 150 r / min and a temperature of 90 °C, carry out a reaction for 12 h to obtain a diamine-terminated polysiloxane; Step A3: Mix the diamine-terminated polysiloxane, precursor, chloroplatinic acid, and DMF evenly, introduce nitrogen protection. Under the conditions of a rotation speed of 200 r / min and a temperature of 85 °C, carry out a reaction for 7 h to obtain a pretreated precursor. Mix the pretreated precursor, intermediate 2, and tetrahydrofuran evenly. Under the conditions of a rotation speed of 120 r / min and a temperature of 80 °C, carry out a reflux reaction for 4 h to obtain a modified filler; 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 tetra(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. Under the conditions that the temperature of zone 1 is 95 °C, the temperature of zone 2 is 100 °C, the temperature of zone 3 is 100 °C, and the temperature of zone 4 is 105 °C, extrude, cool, and pulverize to obtain a highly wear-resistant thermosetting powder coating.

[0026] The molar ratio of the trimellitic triformyl and 3-amino-1,2-propanediol described 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.

[0027] The dosage ratio of the 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.

[0028] The mass ratio of the diamine-terminated polysiloxane to the precursor described in step A3 is 5:1, the dosage of chloroplatinic acid is 1‰ of the mass of the diamine-terminated polysiloxane, and the mass ratio of the pretreated precursor to intermediate 2 is 6:1.

[0029] The precursor described above is prepared by the following steps: Step B1: Mix hexagonal boron nitride and sodium hydroxide solution, under the conditions of a frequency of 25 kHz and a temperature of 20 °C, after ultrasonic treatment for 1.5 h, raise the temperature to 120 °C and carry out reflux treatment for 25 h to obtain hydroxylated hexagonal boron nitride. Disperse the hydroxylated hexagonal boron nitride in ethanol, and under the conditions of a rotation speed of 300 r / min and a temperature of 75 °C, stir and add 3-methacryloxypropyltrimethoxysilane and deionized water, and carry out the reaction for 4 h to obtain modified hexagonal boron nitride; Step B2: Mix methyltrimethoxysilane, isopropanol, deionized water and sodium hydroxide, and under the conditions of a rotation speed of 120 r / min and a temperature of 85 °C, carry out the reaction for 3 h, then cool down to 20 °C and continue the reaction for 12 h to obtain sodium octamethylcyclotetrasiloxanetetrasilanol. Mix sodium octamethylcyclotetrasiloxanetetrasilanol, triethylamine, methyldichlorosilane and tetrahydrofuran, introduce nitrogen protection, and under the conditions of a rotation speed of 200 r / min and a temperature of 3 °C, carry out the reaction for 4 h, then raise the temperature to 20 °C and carry out the reaction for 25 h to obtain dihydroxycage-like silsesquioxane; Step B3: Mix the modified hexagonal boron nitride, dihydroxycage-like silsesquioxane, chloroplatinic acid and DMF evenly, introduce nitrogen protection, and under the conditions of a rotation speed of 500 r / min and a temperature of 85 °C, carry out the reaction for 5 h to obtain the precursor.

[0030] The dosage ratio of the hexagonal boron nitride to the sodium hydroxide solution described in step B1 is 1 g:100 mL, the concentration of the sodium hydroxide solution is 5 mol / L, and the dosage of 3-methacryloxypropyltrimethoxysilane is 1% of the mass of the hydroxylated hexagonal boron nitride.

[0031] The dosage ratio of methyltrimethoxysilane, isopropanol, deionized water and sodium hydroxide described in step B2 is 30 mmol:30 mL:1 mL:20 mmol, and the dosage ratio of sodium octamethylcyclotetrasiloxanetetrasilanol, triethylamine, methyldichlorosilane and tetrahydrofuran is 12 g:4.5 mL:3.5 g:20 mL.

[0032] The molar ratio of the double bond on the modified hexagonal boron nitride to the dihydroxycage-like silsesquioxane described in step B3 is 1:1, and the dosage of chloroplatinic acid is 1‰ of the mass of the dihydroxycage-like silsesquioxane.

[0033] Example 3. A preparation method of a highly wear-resistant thermosetting plastic powder coating specifically includes the following steps: Step A1: Mix trimellitic aldehyde, 3-amino-1,2-propanediol, and methanol evenly. Under the conditions of a rotation speed of 80 r / min and a temperature of 70 °C, reflux and react for 3 h to obtain Intermediate 1. Mix 4-formylphenylboronic acid, Intermediate 1, anhydrous magnesium sulfate, and DMF evenly. Under the conditions of a rotation speed of 300 r / min and a temperature of 25 °C, react for 25 h to obtain Intermediate 2; Step A2: Mix octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, deionized water, and dimethyl sulfoxide. Introduce nitrogen protection. Under the conditions of a rotation speed of 150 r / min and a temperature of 95 °C, react for 12 h to obtain diamine-terminated polysiloxane; Step A3: Mix diamine-terminated polysiloxane, precursor, chloroplatinic acid, and DMF evenly. Introduce nitrogen protection. Under the conditions of a rotation speed of 300 r / min and a temperature of 85 °C, react for 8 h to obtain a pretreated precursor. Mix the pretreated precursor, Intermediate 2, and tetrahydrofuran evenly. Under the conditions of a rotation speed of 150 r / min and a temperature of 80 °C, reflux and react for 5 h to obtain modified filler; 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. Under the conditions that the temperature of zone 1 is 95 °C, the temperature of zone 2 is 100 °C, the temperature of zone 3 is 105 °C, and the temperature of zone 4 is 105 °C, extrude, cool, and pulverize to obtain a high-abrasion-resistant thermosetting powder coating.

[0034] The molar ratio of trimellitic aldehyde to 3-amino-1,2-propanediol described 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.

[0035] The dosage 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.

[0036] The mass ratio of diamine-terminated polysiloxane to precursor described in Step A3 is 5:1, the dosage of chloroplatinic acid is 1‰ of the mass of diamine-terminated polysiloxane, and the mass ratio of the pretreated precursor to Intermediate 2 is 6:1.

[0037] The precursor is prepared by the following steps: Step B1: Mix hexagonal boron nitride and sodium hydroxide solution, under the conditions of a frequency of 30 kHz and a temperature of 25 °C, ultrasonically treat for 1.5 h, then raise the temperature to 125 °C and reflux for 25 h to obtain hydroxylated hexagonal boron nitride. Disperse the hydroxylated hexagonal boron nitride in ethanol, and under the conditions of a rotation speed of 500 r / min and a temperature of 80 °C, stir and add 3-methacryloxypropyltrimethoxysilane and deionized water, and react for 5 h to obtain modified hexagonal boron nitride; Step B2: Mix methyltrimethoxysilane, isopropanol, deionized water and sodium hydroxide, and under the conditions of a rotation speed of 150 r / min and a temperature of 85 °C, react for 3 h, then cool down to 25 °C and continue to react for 12 h to obtain sodium octamethylcyclotetrasiloxanetetrolate. Mix sodium octamethylcyclotetrasiloxanetetrolate, triethylamine, methyldichlorosilane and tetrahydrofuran, introduce nitrogen protection, and under the conditions of a rotation speed of 300 r / min and a temperature of 3 °C, react for 5 h, then raise the temperature to 25 °C and react for 25 h to obtain dihydridosilsesquioxane; Step B3: Mix the modified hexagonal boron nitride, dihydridosilsesquioxane, chloroplatinic acid and DMF evenly, introduce nitrogen protection, and under the conditions of a rotation speed of 600 r / min and a temperature of 85 °C, react for 6 h to obtain a precursor.

[0038] The dosage ratio of the hexagonal boron nitride and the sodium hydroxide solution described in Step B1 is 1 g:100 mL, the concentration of the sodium hydroxide solution is 5 mol / L, and the dosage of 3-methacryloxypropyltrimethoxysilane is 1% of the mass of the hydroxylated hexagonal boron nitride.

[0039] The dosage ratio of methyltrimethoxysilane, isopropanol, deionized water and sodium hydroxide described in Step B2 is 30 mmol:30 mL:1 mL:20 mmol, and the dosage ratio of sodium octamethylcyclotetrasiloxanetetrolate, triethylamine, methyldichlorosilane and tetrahydrofuran is 12 g:4.5 mL:3.5 g:20 mL.

[0040] The molar ratio of the double bond on the modified hexagonal boron nitride and dihydridosilsesquioxane described in Step B3 is 1:1, and the dosage of chloroplatinic acid is 1‰ of the mass of dihydridosilsesquioxane.

[0041] Comparative Example 1: This comparative example is the same as Example 1 except that pentaerythritol tetra(3-mercaptopropionate) is not added.

[0042] Comparative Example 2: This comparative example is the same as Example 1 except that mellitic aldehyde is used instead of Intermediate 2.

[0043] Comparative Example 3: This comparative example is the same as Example 1 except that dimethylsilane is used instead of dihydridosilsesquioxane.

[0044] The powder coatings prepared in Examples 1-3 and Comparative Examples 1-3 were sprayed onto standard test panels by means of high-voltage electrostatic spraying. The thickness of the sprayed coating was about 100 μm. After curing at a temperature of 150 °C for 5 minutes and irradiating with 365 nm ultraviolet light for 8 seconds, the test samples were obtained. A CS-10 grinding wheel loaded with 200 g was tested at a rotational speed of 60 r / min for 1 hour, and the weight loss of the specimens after wear in each example and comparative example was recorded. The hardness of the paint film was detected according to the standard of GB / T 6739-2022. The test results are shown in Table 1 below.

[0045] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Weight loss mg 28 25 24 39 51 63 Film hardness 4H 4H 4H 3H 3H 2H It can be seen from the above table that this application has good wear resistance.

[0046] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the concept of the invention or exceed the scope defined by this claim book, they should fall within the protection scope 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: mixing trimesic acid, 3-amino-1,2-propanediol and methanol for reflux reaction to obtain intermediate 1, and mixing 4-formylphenylboronic acid, intermediate 1, anhydrous magnesium sulfate and DMF for reaction to obtain intermediate 2; Step A2: octamethylcyclotetrasiloxane, methacryloxypropylmethyldiethoxysilane, tetramethylammonium hydroxide, 1,3-bis(aminopropyl)tetramethyldisiloxane, deionized water and dimethyl sulfoxide are mixed, nitrogen is introduced for protection, and a reaction is carried out 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; mixing the pretreated precursor, the intermediate 2 and tetrahydrofuran and reflux reacting 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.

2. The method for preparing a highly wear-resistant thermosetting plastic powder coating according to claim 1, characterized in that: The molar ratio of trimesaldehyde to 3-amino-1,2-propanediol 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, characterized in that: 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, characterized in that: 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, characterized in that: 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.

6. The method for preparing a highly wear-resistant thermosetting plastic powder coating according to claim 1, characterized in that: The precursor is prepared by the following steps: Step B1: mixing hexagonal boron nitride and sodium hydroxide solution, ultrasonically treating, heating and refluxing to obtain hydroxylated hexagonal boron nitride, dispersing the hydroxylated hexagonal boron nitride in ethanol, stirring, adding 3-methacryloxypropyltrimethoxysilane and deionized water, reacting, and obtaining modified hexagonal boron nitride; Step B2: Methyltrimethoxysilane, isopropanol, deionized water and sodium hydroxide are mixed for reaction to obtain sodium octamethylcyclotetrasiloxane tetrasilanolate, sodium octamethylcyclotetrasiloxane tetrasilanolate, triethylamine, methyldichlorosilane and tetrahydrofuran are mixed, nitrogen is introduced for protection, and the mixture is reacted to obtain dihydrogen cage-type silsesquioxane; Step B3: uniformly mix the modified hexagonal boron nitride, dihydrogen cage-type silsesquioxane, chloroplatinic acid and DMF, introduce nitrogen protection, and react to obtain a precursor.

7. The method for preparing a highly wear-resistant thermosetting plastic powder coating according to claim 6, characterized in that: The dosage ratio of the hexagonal boron nitride and the sodium hydroxide solution in step B1 is 1 g:100 mL, and the dosage of 3-methacryloxypropyltrimethoxysilane is 1% of the mass of the hydroxylated hexagonal boron nitride.

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

9. The method for preparing a highly wear-resistant thermosetting plastic powder coating according to claim 6, characterized in that: The molar ratio of the double bonds on the modified hexagonal boron nitride and the dihydrogen cage-type silsesquioxane described in step B3 is 1:

1.

10. A highly wear-resistant thermosetting plastic powder coating, characterized in that: Prepared according to any one of claims 1 to 9.