Anti-fouling powder coating and its preparation method and application

Abstract

The present invention relates to an anti-fouling powder coating, its preparation method, and application. The anti-fouling powder coating comprises the following raw materials in parts by weight: 30 parts of a polysiloxane acrylate polymer; 10-15 parts of hydrophobic fumed silica; 40-60 parts of a bisphenol A epoxy resin; and 10-20 parts of an aromatic polyamine. The polysiloxane acrylate polymer is prepared by copolymerizing monomers including bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate. The anti-fouling powder coating exhibits excellent resistance to water and oil-based stains.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to an anti-fouling powder coating and a preparation method and application thereof. Background Art

[0002] Powder coatings are a type of coating that exists in powder form. They are harmless, highly efficient, resource-saving, and environmentally friendly, and are widely used in construction, electrical appliances, automobiles, and mechanical equipment. Thermosetting powder coatings are composed of thermosetting resins and curing agents. Heat is applied to the thermosetting resins and curing agents, causing them to react and form a resin film, effectively creating a coating.

[0003] As people's quality of life improves, powder coatings are gaining increasing attention for home decoration. When used in kitchens and other environments, the cured coating often comes into contact with water-based and oil-based contaminants, causing adhesion and stains that degrade the appearance. Most existing powder coatings lack effective protection against both water-based and oil-based contaminants. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the first object of the present invention is to provide an anti-fouling powder coating that is resistant to water and oil stains.

[0005] The second object of the present invention is to provide a method for preparing the anti-fouling powder coating.

[0006] The third object of the present invention is to provide applications of the anti-fouling powder coating.

[0007] To achieve the first objective of the present invention, the present invention provides an anti-fouling powder coating, which comprises the following raw materials in parts by weight: 30 parts of a polysiloxane acrylate polymer; 10 to 15 parts of hydrophobic fumed silica; 40 to 60 parts of a bisphenol A epoxy resin; and 10 to 20 parts of an aromatic polyamine. The polysiloxane acrylate polymer is prepared by copolymerizing monomers including bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate.

[0008] In some embodiments of the present invention, the anti-fouling powder coating comprises the following raw materials in parts by mass: 30 parts of polysiloxane acrylate polymer; 10-12 parts of hydrophobic fumed silica; 40-50 parts of bisphenol A epoxy resin; and 15-20 parts of aromatic polyamine.

[0009] In some embodiments of the present invention, in the polysiloxane acrylate polymer, the monomer mass ratio of the double-ended vinyl polysiloxane, the butyl acrylate, the octyl acrylate, the lauryl acrylate, the glycidyl acrylate, and the phenylethyl acrylate is 50: (15-20): (15-20): (15-20): (10-15): (10-15).

[0010] In some embodiments of the present invention, the number average molecular weight of the dual-end vinyl polysiloxane is 500-800.

[0011] In some embodiments of the present invention, the softening temperature of the polysiloxane acrylic oligomer is 70-85°C.

[0012] In some embodiments of the present invention, the particle size of the hydrophobic fumed silica is 30 to 50 nm.

[0013] In some embodiments of the present invention, the bisphenol A epoxy resin is at least one of E12 epoxy resin and E14 epoxy resin.

[0014] In some embodiments of the present invention, the aromatic polyamine is at least one of m-phenylenediamine, m-xylylenediamine, 4,4'-diaminodiphenylmethane, and 4,4'-diaminodiphenylsulfone.

[0015] In order to achieve the second object of the present invention, the present invention provides a method for preparing an anti-fouling powder coating according to any of the above schemes, which comprises the following steps: step 1: preparing a polysiloxane acrylate polymer; step 2: at a first temperature, uniformly mixing the polysiloxane acrylate polymer and bisphenol A epoxy resin, and then adding hydrophobic fumed silica and stirring evenly; step 3: at a second temperature, adding an aromatic polyamine to the mixture obtained in step 2, stirring and dispersing the mixture evenly, wherein the second temperature is lower than the first temperature; step 4: cooling the mixture obtained in step 3 and then crushing it.

[0016] In some embodiments of the present invention, step 1 includes dispersing double-ended vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate and an initiator in a solvent, reacting at a third temperature, and removing the solvent after the reaction to obtain a polysiloxane acrylate polymer.

[0017] In some embodiments of the present invention, the first temperature is 100-120°C, the second temperature is 60-70°C, and the third temperature is 70-80°C.

[0018] In some embodiments of the present invention, the initiator is dibenzoyl peroxide, and the solvent is N-methylpyrrolidone.

[0019] In order to achieve the third object of the present invention, the present invention further provides an anti-fouling coating, which is formed by curing the anti-fouling powder coating described in any of the above technical solutions.

[0020] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0021] The anti-fouling powder coating of the present invention is prepared by adding hydrophobic fumed silica and a polysiloxane acrylate polymer to an epoxy resin system. The polysiloxane acrylate polymer contains polysiloxane and a long-chain alkyl group, which, in combination with the hydrophobic fumed silica, can impart good hydrophobicity and oleophobicity to the coating. The polysiloxane acrylate polymer also contains an epoxy group that participates in the epoxy curing reaction. The polysiloxane acrylate and the hydrophobic fumed silica are evenly dispersed in the coating, so that the obtained coating has good performance in preventing water-based and oil-based fouling. DETAILED DESCRIPTION

[0022] Embodiments of the present invention provide an anti-fouling powder coating that can be sprayed onto an object, for example, using electrostatic spraying, and then cured by heating to form a film, resulting in an anti-fouling coating. The anti-fouling powder coating can be used to protect against water-based or oily stains, such as in the kitchen, where it can be used to decorate or protect kitchen utensils or walls. Of course, the anti-fouling powder coating of the present invention can also be used in other applications, such as for the decoration and protection of outdoor facilities.

[0023] Specifically, the anti-fouling powder coating of this embodiment includes the following raw materials in parts by mass: 30 parts of polysiloxane acrylate polymer; 10-15 parts of hydrophobic fumed silica; 40-60 parts of bisphenol A epoxy resin; and 10-20 parts of aromatic polyamine.

[0024] Wherein, polysiloxane acrylate polymer is made by copolymerization of monomers including double-ended vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate. Double-ended vinyl polysiloxane has a polydimethylsiloxane main chain and vinyl groups at both ends of the main chain. The polydimethylsiloxane main chain has good hydrophobic and oleophobic properties. Vinyl groups can participate in the reaction to incorporate the polydimethylsiloxane main chain into the coating resin matrix to avoid phase separation between the polydimethylsiloxane main chain and the resin matrix. Double-ended vinyl polysiloxane can be prepared by hydrolysis and polycondensation of dichlorodimethylsilane and end-capping with dimethylvinylchlorosilane. Double-ended vinyl polysiloxane can be purchased or made by hand. Butyl acrylate contains butyl, octyl acrylate contains octyl, and lauryl acrylate contains dodecyl. The above-mentioned long-chain alkyl groups form flexible side chains in the polymer. These flexible side chains themselves have good hydrophobicity and can make the coating surface smooth, further improving the waterproofness and oily stickiness of the coating. Glycidyl acrylate has an epoxy group that can participate in the epoxy curing reaction and improve the compatibility of the polysiloxane acrylate polymer with epoxy resins and curing agents. Phenethyl acrylate has a phenyl group and can also improve the compatibility of the polysiloxane acrylate polymer with epoxy resins and curing agents.

[0025] Hydrophobic fumed silica has hydrophobic oleophobicity, and hydrophobic fumed silica is scattered in the coating resin matrix, can improve the performance of the water-repellent property, the oiliness that coats sticks to dirt.Hydrophobic fumed silica can be made by hydrophilic fumed silica and hydrophobic silane such as chlorosilane or hexamethyldisilazane generation chemical reaction, and hydrophobic fumed silica can be bought or homemade and obtain.The hydrophobic fumed silica surface has siloxane structure, and has good compatibility with polysiloxane acrylate polymer, and polysiloxane acrylate polymer can impel hydrophobic fumed silica to disperse in resin matrix, thereby improves the performance of the water-repellent property, the oiliness that coats sticks to dirt better.Be 30 mass parts with respect to the consumption of polysiloxane acrylate polymer, the mass fraction of hydrophobic fumed silica can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts etc.

[0026] Bisphenol A epoxy resin has the glycidyl ether structure of bisphenol A and is the resin body of anti-fouling powder coating. Bisphenol A epoxy resin has good mechanical properties and adhesion, and the epoxy group therein can participate in the curing reaction, and structures such as the phenyl group in the molecule also have good water and oil resistance. Relative to the consumption of polysiloxane acrylate polymer is 30 parts by mass, and the mass fraction of bisphenol A epoxy resin can be 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, etc.

[0027] Aromatic polyamines, used as epoxy curing agents, have at least two amino groups per molecule, which react with epoxy groups to form long-chain cross-linked polymers, resulting in a dense and structurally stable coating. Phenyl groups and other structures within the aromatic polyamine molecules also impart good water and oil resistance. The weight fraction of bisphenol A epoxy resin can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts, relative to 30 parts by weight of the polysiloxane acrylate polymer.

[0028] It can be seen that the anti-fouling powder coating of this embodiment uses bisphenol A epoxy resin and aromatic polyamine to form an aromatic epoxy resin curing system, and adds hydrophobic fumed silica and polysiloxane acrylate polymer to the epoxy resin curing system. The hydrophobic and oleophobic structures in the hydrophobic fumed silica and polysiloxane acrylate polymer are utilized to achieve the waterproofness and oily adsorption functions of the coating. In addition, the components cooperate with each other, and the dispersion of the components in the system is good. The resulting coating surface is smooth and not easy to be contaminated.

[0029] In some examples, the anti-fouling powder coating is primarily composed of the following raw materials in parts by weight: 30 parts polysiloxane acrylate polymer; 10-15 parts hydrophobic fumed silica; 40-60 parts bisphenol A epoxy resin; and 10-20 parts aromatic polyamine. In addition to the polysiloxane acrylate polymer, hydrophobic fumed silica, bisphenol A epoxy resin, and aromatic polyamine, the anti-fouling powder coating may also contain a small amount, such as 0.1-5 parts, of other additives, including pigments.

[0030] In some examples, the anti-fouling powder coating comprises the following raw materials in parts by weight: 30 parts polysiloxane acrylate polymer; 10-15 parts hydrophobic fumed silica; 40-60 parts bisphenol A epoxy resin; and 10-20 parts aromatic polyamine. Besides the polysiloxane acrylate polymer, hydrophobic fumed silica, bisphenol A epoxy resin, and aromatic polyamine, the anti-fouling powder coating contains no other raw materials, resulting in a simpler composition.

[0031] In some examples, the anti-fouling powder coating comprises the following raw materials in parts by weight: 30 parts polysiloxane acrylate polymer; 10-12 parts hydrophobic fumed silica; 40-50 parts bisphenol A epoxy resin; and 15-20 parts aromatic polyamine. When the amounts of each component are within the above ranges, the resulting anti-fouling powder coating exhibits excellent water resistance and oil-resistant properties while also exhibiting enhanced adhesion.

[0032] In some examples, the mass ratio of the monomers of bicap vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate in the polysiloxane acrylate polymer is 50:(15-20):(15-20):(15-20):(10-15):(10-15). When the amounts of the monomers are within this ratio range, the various functional groups cooperate with each other, and the resulting coating has better water resistance and oily stain adhesion. Relative to the mass of 50 parts of double-ended vinyl polysiloxane, the mass of butyl acrylate can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, etc., the mass of octyl acrylate can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, etc., the mass of lauryl acrylate can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, etc., the mass of glycidyl acrylate can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, etc., and the mass of phenylethyl acrylate can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, etc.

[0033] In some examples, the number average molecular weight of the dual-end vinyl polysiloxane is 500 to 800. When the number average molecular weight of the dual-end vinyl polysiloxane is within the above range, the length of the polysiloxane chain segment is moderate, and the dual-end vinyl polysiloxane can be evenly dispersed with other acrylate monomers and has good reactivity to participate in copolymerization reactions.

[0034] In some examples, the polysiloxane acrylate oligomer has a softening temperature of 70-85°C, and the polysiloxane acrylate oligomer has a suitable degree of polymerization, making it more suitable for powder coating applications. The softening temperature or degree of polymerization of the polysiloxane acrylate oligomer can be adjusted by adjusting the amount of polymerization initiator or the reaction time.

[0035] In some examples, the particle size of the hydrophobic fumed silica is 30 to 50 nm. When the particle size of the hydrophobic fumed silica is within the above range, the hydrophobic fumed silica can be better dispersed evenly in the coating resin system.

[0036] In some examples, the bisphenol A epoxy resin is at least one of E12 epoxy resin and E14 epoxy resin. The bisphenol A epoxy resin can remain solid at room temperature, which is conducive to the stable storage of the powder coating.

[0037] In some examples, the aromatic polyamine is at least one of m-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, and 4,4'-diaminodiphenylsulfone. The aromatic polyamine is stable at room temperature and has two amino groups, which can polymerize and crosslink the resin system.

[0038] In some examples, the method for preparing the anti-fouling powder coating of this embodiment may include the following steps:

[0039] Step 1: preparing a polysiloxane acrylate polymer, for example, by thermally or photoinitiated free radical polymerization of monomers to prepare the polysiloxane acrylate polymer.

[0040] Step 2: Evenly mix the polysiloxane acrylate polymer and the bisphenol A epoxy resin at a first temperature, then add the hydrophobic fumed silica and stir evenly to obtain a first mixture. At the first temperature, the polysiloxane acrylate polymer and the bisphenol A epoxy resin are melted and mixed.

[0041] Step 3: At a second temperature, add aromatic polyamine to the first mixture obtained in step 2, stir and disperse evenly to obtain a second mixture. The second temperature is lower than the first temperature. Add curing agent at a lower temperature for mixing to avoid premature polymerization of the resin system.

[0042] Step 4: Cool the second mixture obtained in step 3, for example, to room temperature, and then grind it to obtain an anti-fouling powder coating.

[0043] In some examples, step 1 includes dispersing a bi-vinyl-terminated polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate, and an initiator in a solvent, reacting at a third temperature, and removing the solvent after the reaction to obtain a polysiloxane acrylate polymer. The monomers are copolymerized by free radical polymerization to obtain a copolymer. The amount of initiator used can be 0.5-5% of the total mass of the bi-vinyl-terminated polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate.

[0044] In some examples, the first temperature is 100-120° C., so that the polysiloxane acrylate polymer, bisphenol A epoxy resin, and hydrophobic fumed silica are evenly dispersed.

[0045] In some examples, the second temperature is 60-70° C., so that the curing agent can be evenly mixed with the other raw materials. The curing agent can be melted or dispersed into the other original mixture in the form of solid powder.

[0046] In some examples, the third temperature is 70-80° C., so that the initiator is thermally decomposed to initiate the polymerization reaction.

[0047] In some examples, the initiator is dibenzoyl peroxide, which has the advantages of readily available raw materials and high initiation activity.

[0048] In some examples, the solvent is N-methylpyrrolidone, which has the advantages of being safe, non-toxic, and having good solubility.

[0049] In some examples, this embodiment also provides an anti-fouling coating prepared from the aforementioned anti-fouling powder coating. The anti-fouling coating can be used independently or as a surface coating of a composite coating. The anti-fouling coating can be formed by spraying the aforementioned anti-fouling powder coating onto the surface of an object and then heating and curing it to form a solid resin film.

[0050] The anti-fouling powder coating of the present invention will be further described in detail below through specific examples.

[0051] Example 1

[0052] The steps for preparing the anti-fouling powder coating of this embodiment are as follows:

[0053] Step 1: Disperse bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate, and dibenzoyl peroxide (initiator) in N-methylpyrrolidone. React at 70°C. After completion of the reaction, remove the solvent to obtain a polysiloxane acrylate polymer. The mass ratio of bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate is 50:15:20:15:10:15. The number average molecular weight of the bi-terminal vinyl polysiloxane is approximately 500. The resulting polysiloxane acrylate polymer has a softening temperature of approximately 70°C.

[0054] Step 2: At 100° C., 30 parts of polysiloxane acrylate polymer and 50 parts of bisphenol A epoxy resin E12 were mixed evenly, and then 10 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm was added and stirred evenly.

[0055] Step 3: Add 20 parts of 4,4'-diaminodiphenylmethane to the mixture obtained in step 2 at 70°C, and stir to disperse evenly.

[0056] Step 4: Cooling the mixture obtained in step 3 and then crushing it to obtain an anti-fouling powder coating.

[0057] Example 2

[0058] The steps for preparing the anti-fouling powder coating of this embodiment are as follows:

[0059] Step 1: Disperse bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate, and dibenzoyl peroxide (initiator) in N-methylpyrrolidone. React at 80°C. After completion of the reaction, remove the solvent to obtain a polysiloxane acrylate polymer. The mass ratio of bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate is 50:20:15:20:15:10. The number average molecular weight of the bi-terminal vinyl polysiloxane is approximately 800. The resulting polysiloxane acrylate polymer has a softening temperature of approximately 85°C.

[0060] Step 2: At 120° C., 30 parts of polysiloxane acrylate polymer and 40 parts of bisphenol A epoxy resin E14 were mixed evenly, and then 12 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm was added and stirred evenly.

[0061] Step 3: Add 15 parts of m-xylenediamine to the mixture obtained in step 2 at 60° C. and stir to disperse evenly.

[0062] Step 4: Cooling the mixture obtained in step 3 and then crushing it to obtain an anti-fouling powder coating.

[0063] Example 3

[0064] The steps for preparing the anti-fouling powder coating of this embodiment are as follows:

[0065] Step 1: Disperse bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate, and dibenzoyl peroxide (initiator) in N-methylpyrrolidone. React at 70°C. After completion of the reaction, remove the solvent to obtain a polysiloxane acrylate polymer. The mass ratio of bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate is 50:15:15:20:15:10. The number average molecular weight of the bi-terminal vinyl polysiloxane is approximately 600. The resulting polysiloxane acrylate polymer has a softening temperature of approximately 78°C.

[0066] Step 2: At 100° C., 30 parts of polysiloxane acrylate polymer and 60 parts of bisphenol A epoxy resin E12 were mixed evenly, and then 15 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm was added and stirred evenly.

[0067] Step 3: Add 20 parts of 4,4'-diaminodiphenyl sulfone to the mixture obtained in step 2 at 70°C, and stir to disperse evenly.

[0068] Step 4: Cooling the mixture obtained in step 3 and then crushing it to obtain an anti-fouling powder coating.

[0069] Example 4

[0070] The steps for preparing the anti-fouling powder coating of this embodiment are as follows:

[0071] Step 1: Disperse bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate, and dibenzoyl peroxide (initiator) in N-methylpyrrolidone. React at 70°C. After completion of the reaction, remove the solvent to obtain a polysiloxane acrylate polymer. The mass ratio of bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate is 50:5:5:5:20:20. The number average molecular weight of the bi-terminal vinyl polysiloxane is approximately 800. The resulting polysiloxane acrylate polymer has a softening temperature of approximately 80°C.

[0072] Step 2: At 120° C., 30 parts of polysiloxane acrylate polymer and 40 parts of bisphenol A epoxy resin E14 were mixed evenly, and then 15 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm was added and stirred evenly.

[0073] Step 3: Add 10 parts of m-xylenediamine to the mixture obtained in step 2 at 70°C and stir to disperse evenly.

[0074] Step 4: Cooling the mixture obtained in step 3 and then crushing it to obtain an anti-fouling powder coating.

[0075] Example 5

[0076] The steps for preparing the anti-fouling powder coating of this embodiment are as follows:

[0077] Step 1: Disperse bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate, and dibenzoyl peroxide (initiator) in N-methylpyrrolidone. React at 80°C. After completion of the reaction, remove the solvent to obtain a polysiloxane acrylate polymer. The mass ratio of bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate is 50:25:25:25:5:5. The number average molecular weight of the bi-terminal vinyl polysiloxane is approximately 600. The resulting polysiloxane acrylate polymer has a softening temperature of approximately 83°C.

[0078] Step 2: At 120° C., 30 parts of polysiloxane acrylate polymer and 40 parts of bisphenol A epoxy resin E14 were mixed evenly, and then 15 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm was added and stirred evenly.

[0079] Step 3: Add 15 parts of m-phenylenediamine to the mixture obtained in step 2 at 60°C and stir to disperse evenly.

[0080] Step 4: Cooling the mixture obtained in step 3 and then crushing it to obtain an anti-fouling powder coating.

[0081] Example 6

[0082] The steps for preparing the anti-fouling powder coating of this embodiment are as follows:

[0083] Step 1: Disperse bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate, and dibenzoyl peroxide (initiator) in N-methylpyrrolidone. React at 80°C. After completion of the reaction, remove the solvent to obtain a polysiloxane acrylate polymer. The mass ratio of bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate is 50:15:20:15:10:15. The number average molecular weight of the bi-terminal vinyl polysiloxane is approximately 1000. The resulting polysiloxane acrylate polymer has a softening temperature of approximately 81°C.

[0084] Step 2: At 100° C., 30 parts of polysiloxane acrylate polymer and 50 parts of bisphenol A epoxy resin E12 were mixed evenly, and then 10 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm was added and stirred evenly.

[0085] Step 3: Add 20 parts of 4,4'-diaminodiphenylmethane to the mixture obtained in step 2 at 60°C, and stir to disperse evenly.

[0086] Step 4: Cooling the mixture obtained in step 3 and then crushing it to obtain an anti-fouling powder coating.

[0087] Comparative Example 1

[0088] The powder coating preparation steps of this comparative example are as follows:

[0089] Step 1: Disperse bi-terminal vinyl polysiloxane, octyl acrylate, lauryl acrylate, glycidyl acrylate, and the initiator dibenzoyl peroxide in N-methylpyrrolidone. React at 70°C. After completion of the reaction, remove the solvent to obtain a polysiloxane acrylate polymer. The mass ratio of bi-terminal vinyl polysiloxane, octyl acrylate, lauryl acrylate, and glycidyl acrylate is 50:15:20:10. The number average molecular weight of the bi-terminal vinyl polysiloxane is approximately 600. The resulting polysiloxane acrylate polymer has a softening temperature of approximately 72°C.

[0090] Step 2: At 120° C., 30 parts of polysiloxane acrylate polymer and 50 parts of bisphenol A epoxy resin E12 were mixed evenly, and then 10 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm was added and stirred evenly.

[0091] Step 3: Add 20 parts of m-xylenediamine to the mixture obtained in step 2 at 70° C. and stir to disperse evenly.

[0092] Step 4: Cool the mixture obtained in step 3 and then crush it to obtain a powder coating.

[0093] Comparative Example 2

[0094] The powder coating preparation steps of this comparative example are as follows:

[0095] Step 1: At 120° C., mix 30 parts of double-terminated vinyl polysiloxane and 50 parts of bisphenol A epoxy resin E12, and then add 10 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm and stir evenly.

[0096] Step 2: Add 20 parts of m-xylenediamine to the mixture obtained in step 2 at 60° C. and stir to disperse evenly.

[0097] Step 3: Cool the mixture obtained in step 3 and then crush it to obtain a powder coating.

[0098] Comparative Example 3

[0099] The powder coating preparation steps of this comparative example are as follows:

[0100] Step 1: Disperse bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate, and dibenzoyl peroxide (initiator) in N-methylpyrrolidone. React at 70°C. After completion of the reaction, remove the solvent to obtain a polysiloxane acrylate polymer. The mass ratio of bi-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate is 50:15:20:15:10:15. The number average molecular weight of the bi-terminal vinyl polysiloxane is approximately 600. The resulting polysiloxane acrylate polymer has a softening temperature of approximately 77°C.

[0101] Step 2: At 120° C., mix 30 parts of polysiloxane acrylate polymer and 50 parts of bisphenol A epoxy resin E12 evenly, then add 10 parts of silicon micropowder with a particle size of 10 to 30 μm and stir evenly.

[0102] Step 3: Add 20 parts of m-xylenediamine to the mixture obtained in step 2 at 60° C. and stir to disperse evenly.

[0103] Step 4: Cool the mixture obtained in step 3 and then crush it to obtain a powder coating.

[0104] The powder coatings prepared in the above embodiments and comparative examples were electrostatically sprayed onto a substrate and then baked at 150°C for 20 minutes to obtain a coating having a thickness of approximately 0.3 mm. A 20% aqueous hydrochloric acid solution containing methyl red, a 20% aqueous sodium hydroxide solution containing phenolphthalein, and cyclohexane containing a dye were applied to different local locations on the coating. After 40 minutes of application, the coatings were wiped clean with ethanol using a non-woven fabric. The initial coatings and those treated with acid, alkali, and oil-based coatings were tested. The water contact angle was measured using a contact angle tester, while the oil contact angle was measured using a contact angle tester using peanut oil. Hardness testing was performed according to GB / T 6739-1996. The test results are shown in Table 1 below.

[0105] Table 1 Test results

[0106]

[0107]

[0108] As can be seen from the above, the anti-fouling powder coating of the present invention has large water and oil contact angles, good resistance to acidic and alkaline aqueous solutions, and oily solvents, and maintains a good appearance and hardness after treatment with acidic and alkaline aqueous solutions and oily solvents. Comparative Example 1 lacks some monomers in the polysiloxane acrylate polymer, Comparative Example 2 uses a bivalent vinyl-terminated polysiloxane instead of the polysiloxane acrylate polymer, and Comparative Example 3 uses silica powder instead of hydrophobic fumed silica. The resulting coatings have poor water resistance and oily fouling resistance.

[0109] Finally, it should be emphasized that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. An anti-fouling powder coating, characterized in that It is composed of the following raw materials in parts by mass: 30 parts of polysiloxane acrylate polymer; 10-12 parts of hydrophobic fumed silica; 40-50 parts of bisphenol A epoxy resin; 15-20 parts of aromatic polyamine; The polysiloxane acrylate polymer is prepared by copolymerizing monomers of bicap vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate. In the polysiloxane acrylate polymer, the monomer mass ratio of the bicap vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate is 50:(15-20):(15-20):(15-20):(10-15):(10-15); the number average molecular weight of the bicap vinyl polysiloxane is 500-800; The particle size of the hydrophobic fumed silica is 30 to 50 nm; The coating surface prepared from the anti-fouling powder coating is smooth.

2. The anti-fouling powder coating according to claim 1, characterized in that The softening temperature of the polysiloxane acrylate polymer is 70-85°C.

3. An anti-fouling powder coating according to claim 1 or 2, characterized in that The bisphenol A epoxy resin is at least one of E12 epoxy resin and E14 epoxy resin; The aromatic polyamine is at least one of m-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, and 4,4'-diaminodiphenylsulfone.

4. The method for preparing an anti-fouling powder coating according to any one of claims 1 to 3, characterized in that The following steps are involved: Step 1: preparing polysiloxane acrylate polymer; Step 2: at a first temperature, uniformly mix the polysiloxane acrylate polymer and the bisphenol A epoxy resin, and then add the hydrophobic fumed silica and stir evenly; Step 3: adding aromatic polyamine to the mixture obtained in step 2 at a second temperature, stirring and dispersing the mixture uniformly, wherein the second temperature is lower than the first temperature; Step 4: Cool the mixture obtained in step 3 and then crush it.

5. The preparation method according to claim 4, characterized in that The step 1 comprises dispersing double-ended vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate and an initiator in a solvent, reacting at a third temperature, and removing the solvent after the reaction to obtain a polysiloxane acrylate polymer.

6. The preparation method according to claim 5, characterized in that The first temperature is 100-120° C., the second temperature is 60-70° C., and the third temperature is 70-80° C.; The initiator is dibenzoyl peroxide, and the solvent is N-methylpyrrolidone.

7. An anti-fouling coating, characterized in that The anti-fouling coating is formed by curing the anti-fouling powder coating according to any one of claims 1 to 3 or the anti-fouling powder coating prepared by the preparation method according to claim 4 or 5.

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