Anti-sticking powder coating as well as preparation method and application thereof

Abstract

The invention relates to an anti-sticking powder coating as well as a preparation method and application thereof. The anti-sticking powder coating comprises the following raw materials in parts by mass: 30 parts of polysiloxane acrylate polymer; 10 to 15 parts of hydrophobic fumed silica; 40 to 60 parts of bisphenol A epoxy resin; 10 to 20 parts of aromatic polyamine; wherein the polysiloxane acrylate polymer is prepared by copolymerizing monomers including double-end vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate and phenethyl acrylate. The anti-contamination powder coating can well resist water and oily sticky dirt.

Description

Technical Field

[0001] The 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 coating is a kind of coating in powder form, which is harmless, efficient, resource-saving and environmentally friendly, and is widely used in construction, electrical appliances, automobiles, mechanical equipment, etc. Among them, thermosetting powder coating is composed of thermosetting resin, curing agent, etc., and the thermosetting resin and curing agent react by heating to form a resin film, that is, a coating.

[0003] As people's quality of life improves, powder coatings are increasingly being used in home decoration. When powder coatings are used in scenes such as kitchens, the coating formed by the solidification of powder coatings usually comes into contact with water-based pollutants and oily pollutants, thereby adhering to pollutants and forming stains on the coating, affecting the appearance. Most existing powder coatings cannot effectively prevent both water-based and oily contamination. Summary of the invention

[0004] In view of the shortcomings of the prior art, the first object of the present invention is to provide an anti-fouling powder coating, which can effectively resist 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 the application of the anti-fouling powder coating.

[0007] To achieve the first object of the present invention, the present invention provides an anti-fouling powder coating, which comprises the following raw materials in parts by mass: 30 parts of polysiloxane acrylate polymer; 10 to 15 parts of hydrophobic fumed silica; 40 to 60 parts of bisphenol A epoxy resin; and 10 to 20 parts of aromatic polyamine; wherein the polysiloxane acrylate polymer is prepared by copolymerizing monomers including double-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 weight: 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-terminated 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 30-50 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 meta-phenylenediamine, meta-xylylenediamine, 4,4'-diaminodiphenylmethane, and 4,4'-diaminodiphenyl sulfone.

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

[0016] In some embodiments of the present invention, step one 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.

[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 polysiloxane acrylate polymer into an epoxy resin system, wherein the polysiloxane acrylate polymer contains polysiloxane and a long-chain alkyl group, which cooperates with the hydrophobic fumed silica to give the coating good hydrophobic and oleophobic properties. The polysiloxane acrylate polymer also contains an epoxy group to participate 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] An embodiment of the present invention provides an anti-fouling powder coating, which can be sprayed, for example, electrostatically sprayed onto an object, and heated and cured to form a film to obtain an anti-fouling coating. The anti-fouling powder coating can be used in situations where water or oil stains are required, for example, it can be used in kitchen scenes, used as surface decoration or protection for kitchen utensils or walls. Of course, the anti-fouling powder coating of the present invention can also be used in other scenes, 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 prepared by copolymerization of monomers including double-end vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate. Double-end 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 so as to combine the polydimethylsiloxane main chain into the coating resin matrix to avoid phase separation between the polydimethylsiloxane main chain and the resin matrix. Double-end vinyl polysiloxane can be prepared by hydrolysis and polycondensation of dichlorodimethylsilane and end-capping with dimethylvinyl chlorosilane. Double-end vinyl polysiloxane can be obtained by purchase or self-production. 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 sticky properties of the coating. Glycidyl acrylate has an epoxy group, which can participate in the epoxy curing reaction and improve the compatibility of the polysiloxane acrylate polymer with the epoxy resin and the curing agent. Phenyl acrylate has a phenyl group, which can also improve the compatibility of the polysiloxane acrylate polymer with the epoxy resin and the curing agent.

[0025] Hydrophobic fumed silica has hydrophobic oleophobicity, and hydrophobic fumed silica is dispersed in the coating resin matrix, and can improve the performance of the water resistance and oiliness of coating. Hydrophobic fumed silica can be prepared by chemical reaction of hydrophilic fumed silica and hydrophobic silane such as chlorosilane or hexamethyldisilazane, and hydrophobic fumed silica can be purchased or homemade. The hydrophobic fumed silica surface has siloxane structure, and has good compatibility with polysiloxane acrylate polymer, and polysiloxane acrylate polymer can promote hydrophobic fumed silica to disperse in resin matrix, thus better improve the performance of the water resistance and oiliness of coating. The consumption relative to polysiloxane acrylate polymer is 30 mass parts, and 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, is the resin body of anti-fouling powder coating.Bisphenol A epoxy resin has good mechanical property and adhesion, and epoxy group therein can participate in curing reaction, and structures such as phenyl in molecule also have good water and oil resistance.With respect 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 polyamine is used as epoxy curing agent, and has at least two amino groups in one molecule, which can react with epoxy groups to obtain long-chain cross-linked polymers, and obtain a coating with compactness and structural stability. The structures such as phenyl in the aromatic polyamine molecules also have good water and oil resistance. With respect to the amount of polysiloxane acrylate polymer used being 30 parts by mass, the mass fraction of bisphenol A type epoxy resin can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, etc.

[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 adhesion functions of the coating, and the components cooperate with each other, and the dispersion of each component in the system is good. The resulting coating has a smooth surface and is not easy to be contaminated.

[0029] In some examples, the anti-fouling powder coating is mainly composed of 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; 10-20 parts of aromatic polyamine. In addition to polysiloxane acrylate polymer, hydrophobic fumed silica, bisphenol A epoxy resin and aromatic polyamine, the anti-fouling powder coating may also contain a small amount of other additives, such as 0.1-5 parts, including pigments.

[0030] In some examples, the anti-fouling powder coating is composed of 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. In addition to the polysiloxane acrylate polymer, hydrophobic fumed silica, bisphenol A epoxy resin, and aromatic polyamine, the anti-fouling powder coating does not contain other raw materials and has a simpler composition.

[0031] In some examples, the anti-fouling powder coating includes the following raw materials in parts by weight: 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. When the amount of each component is within the above range, the coating obtained by the anti-fouling powder coating has good water resistance and oily stain resistance, and has higher adhesion.

[0032] In some examples, in the polysiloxane acrylate polymer, the monomer mass ratio of double-terminal 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). When the amount of each monomer is within the above ratio range, various functional groups cooperate with each other, and the resulting coating has better water resistance and oily stain resistance. 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-terminal vinyl polysiloxane is 500 to 800. When the number average molecular weight of the dual-terminal vinyl polysiloxane is within the above range, the length of the polysiloxane chain segment is moderate, and the dual-terminal vinyl polysiloxane can be evenly dispersed with other acrylate monomers and has good reactivity to participate in copolymerization reactions.

[0034] In some examples, the softening temperature of the polysiloxane acrylic oligomer is 70-85° C., and the polysiloxane acrylic oligomer has a suitable degree of polymerization and is better used for powder coating applications. The softening temperature or degree of polymerization of the polysiloxane acrylic oligomer can be obtained by adjusting the amount of polymerization initiator or 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 beneficial to the stable preservation 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'-diaminodiphenyl sulfone. 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: at a first temperature, the polysiloxane acrylate polymer and the bisphenol A epoxy resin are mixed evenly, and then the hydrophobic fumed silica is added and stirred 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, cool it to room temperature and then pulverize it to obtain an anti-fouling powder coating.

[0043] In some examples, step one includes dispersing double-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate and an initiator in a solvent, reacting at a third temperature, removing the solvent after the reaction, and obtaining a polysiloxane acrylate polymer. Each monomer is copolymerized by free radical polymerization to obtain a copolymer. The amount of the initiator can be 0.5 to 5% of the total mass of double-terminal vinyl 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 other raw materials. The curing agent can be melted or dispersed into other original mixtures 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 easy availability of 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, the present embodiment also provides an anti-fouling coating prepared from the anti-fouling powder coating, which can be used independently or as a surface coating of a composite coating. The anti-fouling coating can be formed by spraying the anti-fouling powder coating on the surface of an object and then heating and curing 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 double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate and initiator dibenzoyl peroxide in solvent N-methylpyrrolidone, react at 70°C, remove the solvent after the reaction, and obtain polysiloxane acrylate polymer. Among them, the mass ratio of double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate and phenylethyl acrylate is 50:15:20:15:10:15, and the number average molecular weight of double-terminated vinyl polysiloxane is about 500. The softening temperature of the obtained polysiloxane acrylate polymer is about 70°C.

[0054] Step 2: At 100° C., 30 parts of polysiloxane acrylate polymer and 50 parts of bisphenol A epoxy resin E12 are mixed evenly, and then 10 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm are 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: Cool the mixture obtained in step 3 and then crush 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 double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate and initiator dibenzoyl peroxide in solvent N-methylpyrrolidone, react at 80°C, remove the solvent after the reaction, and obtain polysiloxane acrylate polymer. Among them, the mass ratio of double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate is 50:20:15:20:15:10, and the number average molecular weight of double-terminated vinyl polysiloxane is about 800. The softening temperature of the obtained polysiloxane acrylate polymer is about 85°C.

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

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

[0062] Step 4: Cool the mixture obtained in step 3 and then crush 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 double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate and initiator dibenzoyl peroxide in solvent N-methylpyrrolidone, react at 70°C, remove the solvent after the reaction, and obtain polysiloxane acrylate polymer. Among them, the mass ratio of double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate is 50:15:15:20:15:10, and the number average molecular weight of double-terminated vinyl polysiloxane is about 600. The softening temperature of the obtained polysiloxane acrylate polymer is about 78°C.

[0066] Step 2: At 100° C., 30 parts of polysiloxane acrylate polymer and 60 parts of bisphenol A epoxy resin E12 are mixed evenly, and then 15 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm are 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: Cool the mixture obtained in step 3 and then crush 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 double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate and initiator dibenzoyl peroxide in solvent N-methylpyrrolidone, react at 70°C, remove the solvent after the reaction, and obtain polysiloxane acrylate polymer. The mass ratio of double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate and phenylethyl acrylate is 50:5:5:5:20:20, and the number average molecular weight of double-terminated vinyl polysiloxane is about 800. The softening temperature of the obtained polysiloxane acrylate polymer is about 80°C.

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

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

[0074] Step 4: Cool the mixture obtained in step 3 and then crush 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 double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate and initiator dibenzoyl peroxide in solvent N-methylpyrrolidone, react at 80°C, remove the solvent after the reaction, and obtain polysiloxane acrylate polymer. Among them, the mass ratio of double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate and phenylethyl acrylate is 50:25:25:25:5:5, and the number average molecular weight of double-terminated vinyl polysiloxane is about 600. The softening temperature of the obtained polysiloxane acrylate polymer is about 83°C.

[0078] Step 2: At 120° C., 30 parts of polysiloxane acrylate polymer and 40 parts of bisphenol A epoxy resin E14 are mixed evenly, and then 15 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm are 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: Cool the mixture obtained in step 3 and then crush 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 double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate and initiator dibenzoyl peroxide in solvent N-methylpyrrolidone, react at 80°C, remove the solvent after the reaction, and obtain polysiloxane acrylate polymer. The mass ratio of double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate and phenylethyl acrylate is 50:15:20:15:10:15, and the number average molecular weight of double-terminated vinyl polysiloxane is about 1000. The softening temperature of the obtained polysiloxane acrylate polymer is about 81°C.

[0084] Step 2: At 100° C., 30 parts of polysiloxane acrylate polymer and 50 parts of bisphenol A epoxy resin E12 are mixed evenly, and then 10 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm are 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: Cool the mixture obtained in step 3 and then crush 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 double-terminated vinyl polysiloxane, octyl acrylate, lauryl acrylate, glycidyl acrylate and initiator dibenzoyl peroxide in solvent N-methylpyrrolidone, react at 70°C, remove the solvent after the reaction, and obtain polysiloxane acrylate polymer. Among them, the mass ratio of double-terminated vinyl polysiloxane, octyl acrylate, lauryl acrylate and glycidyl acrylate is 50:15:20:10, and the number average molecular weight of double-terminated vinyl polysiloxane is about 600. The softening temperature of the obtained polysiloxane acrylate polymer is about 72°C.

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

[0091] Step 3: Add 20 parts of m-phenylenediamine 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., 30 parts of double-terminated vinyl polysiloxane and 50 parts of bisphenol A epoxy resin E12 are mixed evenly, and then 10 parts of hydrophobic fumed silica with a particle size of 30 to 50 nm are added and stirred evenly.

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

[0097] Step 3: The mixture obtained in step 3 is cooled and then crushed 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 double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, phenylethyl acrylate and initiator dibenzoyl peroxide in solvent N-methylpyrrolidone, react at 70°C, remove the solvent after the reaction, and obtain polysiloxane acrylate polymer. Among them, the mass ratio of double-terminated vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate is 50:15:20:15:10:15, and the number average molecular weight of double-terminated vinyl polysiloxane is about 600. The softening temperature of the obtained polysiloxane acrylate polymer is about 77°C.

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

[0102] Step 3: Add 20 parts of m-phenylenediamine 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 about 0.3 mm. A 20% aqueous solution of hydrochloric acid with methyl red added, a 20% aqueous solution of sodium hydroxide with phenolphthalein added, and cyclohexane with dyes added were coated on different local positions of the coating, and 40 minutes after coating, the coatings were wiped off with ethanol dipped in a non-woven fabric. The initial coating and the coating parts treated with acid, alkali and oily coatings were tested respectively, wherein the water contact angle was measured using water on a contact angle tester, the oil contact angle was measured using peanut oil on a contact angle tester, and the hardness test was performed with reference 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 a large water contact angle and an oil contact angle, has good tolerance to acidic aqueous solutions, alkaline aqueous solutions and oily solvents, and can maintain good appearance and hardness after being treated with acidic aqueous solutions, alkaline aqueous solutions and oily solvents. The polysiloxane acrylate polymer of Comparative Example 1 lacks some monomers, Comparative Example 2 uses double-terminal vinyl polysiloxane instead of polysiloxane acrylate polymer, and Comparative Example 3 uses silicon powder instead of hydrophobic fumed silica, and the resulting coating has poor water resistance and oily stain 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 modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An anti-fouling powder coating, characterized in that The invention comprises the following raw materials in parts by weight: 30 parts of polysiloxane acrylate polymer; 10-15 parts of hydrophobic fumed silica; 40-60 parts of bisphenol A epoxy resin; 10-20 parts of aromatic polyamine; The polysiloxane acrylate polymer is prepared by copolymerizing monomers including double-terminal vinyl polysiloxane, butyl acrylate, octyl acrylate, lauryl acrylate, glycidyl acrylate, and phenylethyl acrylate.

2. The anti-fouling powder coating according to claim 1, characterized in that The invention comprises the following raw materials in parts by weight: 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.

3. The anti-fouling powder coating according to claim 1 or 2, characterized in that 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).

4. The anti-fouling powder coating according to claim 1 or 2, characterized in that The number average molecular weight of the double-terminated vinyl polysiloxane is 500 to 800; The softening temperature of the polysiloxane acrylic oligomer is 70-85°C.

5. The anti-fouling powder coating according to claim 1 or 2, characterized in that The particle size of the hydrophobic fumed silica is 30 to 50 nm.

6. The 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 meta-phenylenediamine, meta-xylylenediamine, 4,4'-diaminodiphenylmethane and 4,4'-diaminodiphenyl sulfone.

7. The method for preparing an anti-fouling powder coating according to any one of claims 1 to 6, 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.

8. The preparation method according to claim 7, characterized in that The step 1 comprises dispersing double-terminated 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 is completed to obtain a polysiloxane acrylate polymer.

9. The preparation method according to claim 8, 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.

10. An anti-fouling coating, characterized in that The anti-fouling coating is formed by curing an anti-fouling powder coating according to any one of claims 1 to 6 or an anti-fouling powder coating prepared by the preparation method according to any one of claims 7 to 9.

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