Coating composition having mold-proof and antibacterial properties and preparation method therefor

Abstract

The present invention relates to the technical field of coatings. Disclosed are a coating composition having mold-proof and antibacterial properties and a preparation method therefor. The coating composition comprises the following raw materials: an acrylic resin emulsion, a curing agent, a coalescing agent, a defoaming agent, and a leveling agent, wherein the acrylic resin emulsion is prepared from an acrylate monomer, a cross-linking agent, and fluorine-containing silicone oil by means of free radical polymerization under the action of an initiator. A gemini-type quaternary ammonium salt functional group in the structure of the cross-linking agent can enable the coating to have good mold-proof and antibacterial effects, the presence of the ether bond can enable the coating to have better adhesive force, and the presence of the fluorine-containing silicone oil can enable a coating film formed by curing the coating to have a super-hydrophobic surface, thereby avoiding surface moisture which promotes bacterial growth and reproduction, and endowing the coating with antifouling and self-cleaning effects. In addition, the silicon-oxygen bond in the silicone oil can effectively enhance the heat resistance of the coating, thereby facilitating further application of the coating in indoor decoration.

Description

A coating composition with mildew-proof and antibacterial properties and a preparation method thereof Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a coating composition with mildew and antibacterial properties and a preparation method thereof. Background Art

[0002] With the continuous development of the construction industry, interior decoration has become a top priority. Among them, the kitchen is indispensable for every family. At present, kitchen wall decoration mostly adopts ceramic tiles, tempered glass and paint, while ceiling materials generally use plastic materials. Since the kitchen is in a special humid and hot environment for a long time, it is easy to cause the plastic material to age and lose its original decorative effect. Therefore, in actual application, organic polymer coatings are often applied on the plastic surface. After curing, the coating can form a coating film, which protects the plastic material and plays a role in delaying the aging of the plastic material.

[0003] Currently, the main organic polymer coatings used on the market are epoxy resins, polyurethanes, and acrylates. Acrylic coatings, with their advantages of excellent gloss and color retention, soft gloss, and strong adhesion, are widely used in interior decoration. However, acrylic coatings are susceptible to bacterial growth in hot and humid environments, which are conducive to bacterial growth and reproduction, causing the cured coating film to mold, which not only loses its original protective function but also poses health concerns. Furthermore, acrylic resin coatings have poor heat resistance and can decompose, age, and yellow in hot and humid environments, causing the coating film to fall off and lose its protective function. Therefore, the application of acrylic coatings in kitchens still needs to overcome these drawbacks.

[0004] Patent application number CN201410020505.4 discloses a method for preparing an environmentally friendly, antibacterial acrylic resin coating that can be used for walls, wood, and metal equipment. The method uses modified liposomes to encapsulate mugwort oil to form a mugwort oil coating liquid. Adding the coating liquid during the preparation of the acrylic resin can improve the antibacterial durability of the acrylic resin. However, mugwort oil has poor stability, and simple physical mixing easily causes precipitation of the antibacterial agent. Therefore, it is difficult to ensure the long-lasting antibacterial effect of the acrylic resin. Summary of the Invention

[0005] The purpose of the present invention is to provide a coating composition with mildew and antibacterial properties and a preparation method thereof, which solves the problem that acrylic coatings have poor mildew and antibacterial properties and heat resistance.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A coating composition with mildew and antibacterial properties, comprising the following raw materials, by weight: 35-45 parts of acrylic resin emulsion, 2-3 parts of curing agent, 1.5-2 parts of film-forming aid, 1-2 parts of defoaming agent, and 0.2-0.5 parts of leveling agent;

[0008] The acrylic resin emulsion comprises the following raw materials in parts by weight: 10-25 parts of methyl methacrylate, 5-15 parts of ethyl acrylate, 1-3 parts of acrylic acid, 2-3.5 parts of glycidyl methacrylate, 1-2 parts of a crosslinking agent, 2-6 parts of fluorinated silicone oil, 0.1-0.3 parts of an initiator, 1-2 parts of an emulsifier, and 20-35 parts of purified water;

[0009] The preparation method of the acrylic resin emulsion is specifically as follows:

[0010] Mix parts by weight of methyl methacrylate, ethyl acrylate, acrylic acid, glycidyl methacrylate, emulsifier and purified water, stir evenly, raise the temperature to 80-90°C, continue to add parts by weight of crosslinking agent and fluorinated silicone oil, add initiator, after addition, keep warm and stir for 6-9 hours, cool and discharge;

[0011] The cross-linking agent is a vinyl-terminated polyethylene glycol cross-linking agent containing a gemini quaternary ammonium salt antibacterial functional group in its structure;

[0012] The fluorine-containing silicone oil is a silicone oil derivative grafted with a fluorine-containing hydrophobic group.

[0013] In the above technical solution, under the action of an initiator, methyl methacrylate, ethyl acrylate, acrylic acid, glycidyl methacrylate, a crosslinker and the unsaturated olefin groups in the structure of fluorinated silicone oil can undergo free radical polymerization, and under the action of an emulsifier, an acrylic resin emulsion can be prepared.

[0014] Furthermore, the curing agent is aziridine; the film-forming aid is any one of propylene glycol methyl ether or ethylene glycol butyl ether; the defoaming agent is any one of fatty alcohol polyoxyethylene ether or alkylphenol polyoxyethylene ether; the leveling agent is sodium polyacrylate; the initiator is any one of azobisisobutylamine hydrochloride or azobiscyanovaleric acid; and the emulsifier is any one of sodium dodecyl sulfate or sodium dodecylbenzenesulfonate.

[0015] Furthermore, the preparation method of the cross-linking agent specifically comprises the following steps:

[0016] Step 1: Mix polyethylene glycol diglycidyl ether, tertiary amine monomer and ethanol, stir evenly, pass nitrogen protection, raise the temperature to 60-65°C, stir for 2-3 hours, add glacial acetic acid dropwise to adjust the pH to 6-7, continue stirring for 6-8 hours, evaporate the solvent, remove unreacted products, and obtain a cross-linked intermediate;

[0017] Step 2: Mix the cross-linking intermediate, acrylic isocyanate and toluene, stir evenly, introduce nitrogen, add the catalyst, start stirring, stir at 70-75°C for 6-12 hours, evaporate the solvent, remove the unreacted products, cool and discharge the material to obtain the cross-linking agent.

[0018] Furthermore, in the first step, the tertiary amine monomer is any one of N,N-dimethylhexylamine, N,N-dimethyl-n-octylamine, N,N-dimethyldodecylamine or hexadecyldimethyl tertiary amine.

[0019] Furthermore, in the second step, the acrylic isocyanate is any one of isocyanoethyl methacrylate or isocyanate ethyl acrylate.

[0020] Furthermore, in the second step, the catalyst is any one of dibutyltin dilaurate or stannous octoate.

[0021] In the above technical solution, the polyethylene glycol diglycidyl ether molecular chain end contains an active epoxy group, which can undergo a quaternization ring-opening reaction with a tertiary amine monomer to form a cross-linked intermediate with a long-chain quaternary ammonium salt functional group at the molecular chain end. Since active hydroxyl groups are generated during the ring-opening reaction, they can undergo an amine esterification reaction with the isocyanate group in the acrylic isocyanate structure under the action of a catalyst, thereby preparing a vinyl-terminated polyethylene glycol cross-linker containing a gemini quaternary ammonium salt antibacterial functional group in its structure.

[0022] Furthermore, the preparation method of the fluorine-containing silicone oil is specifically as follows:

[0023] Mix hydroxy vinyl silicone oil and tetrahydrofuran, stir until a uniform solution is formed, continue to add fluorine-containing carboxylic acid, dicyclohexylcarbodiimide and 4-dimethylaminopyridine, pass nitrogen, stir at room temperature for 4-8 hours, evaporate the solvent, remove unreacted materials, and discharge to obtain fluorine-containing silicone oil.

[0024] Furthermore, the hydroxy vinyl silicone oil has a vinyl content of 10% and a hydroxyl content of 8%.

[0025] Furthermore, the fluorine-containing carboxylic acid is any one of trifluorobutyric acid or 5,5,5-trifluoropentanoic acid.

[0026] In the above technical solution, the hydroxy vinyl silicone oil structure contains active hydroxyl groups, which can undergo esterification condensation with the carboxyl groups in the fluorine-containing carboxylic acid structure under the joint action of dicyclohexylcarbodiimide and 4-dimethylaminopyridine, thereby introducing a fluorine-containing hydrophobic chain segment into the hydroxy vinyl silicone oil structure to prepare fluorine-containing silicone oil.

[0027] A method for preparing a coating composition having mildew and antibacterial properties comprises the following steps:

[0028] Step 1: Take parts by weight of acrylic resin emulsion, film-forming aid, defoaming agent and leveling agent, pour them into a mixer, stir and mix them evenly, let them stand to defoam, and form a premix;

[0029] Step 2: Stir and mix the curing agent and premix by weight to form a uniform material, and store it at room temperature.

[0030] Beneficial effects of the present invention:

[0031] (1) The present invention prepares a vinyl-terminated polyethylene glycol crosslinker containing a gemini quaternary ammonium salt antibacterial functional group in its structure and participates in the preparation process of the acrylic resin emulsion, thereby introducing polyethylene glycol segments into the acrylic resin structure. The ether bonds rich in the polyethylene glycol segments can generate more hydrogen bonds with the adhered substrate, and the cohesive force of the acrylic resin molecular chain after crosslinking is greater, which can effectively improve the adhesion between the coating and the adhered substrate. At the same time, the crosslinker structure also contains a gemini quaternary ammonium salt antibacterial group. Since the quaternary ammonium salt functional group has a broad-spectrum antibacterial effect, after the gemini quaternary ammonium salt antibacterial group is introduced into the acrylic resin structure, it can give the coating a good antibacterial and mildew-proof effect. In addition, since the antibacterial agent is grafted into the acrylic resin molecular chain in a free radical polymerization manner, the precipitation problem of the antibacterial agent can be avoided.

[0032] (2) The present invention prepares fluorine-containing silicone oil and participates in the preparation of acrylic resin emulsion. The surface energy of the silicone oil modified with fluorine-containing groups is extremely low, and it can be freed to the surface of the coating during the curing stage of the coating. The strong hydrophobicity of the fluorine-containing groups and silicone oil is used to form a super-hydrophobic surface of the coating, which in turn plays a role in isolating water vapor, keeping the coating surface in a dry environment, avoiding providing a favorable humid environment for the growth and reproduction of bacteria, and indirectly achieving the effect of mildew and antibacterial of the coating. At the same time, the super-hydrophobic surface can also make the coating produce an anti-fouling and self-cleaning effect. In addition, the high bond energy of the silicon-oxygen bond in the silicone oil can improve the heat resistance of the acrylic resin, thereby reducing the decomposition and yellowing of the coating at higher temperatures, which is beneficial to improving the service life of the coating.

[0033] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] FIG1 is an infrared spectrum of the cross-linking agent prepared in Example 1 of the present invention. Implementation Method

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention. Example

[0037] A coating composition with mildew and antibacterial properties, comprising the following raw materials, by weight: 35 parts of acrylic resin emulsion, 2 parts of aziridine as a curing agent, 1.5 parts of propylene glycol methyl ether as a film-forming aid, 1 part of fatty alcohol polyoxyethylene ether as a defoaming agent, and 0.2 parts of sodium polyacrylate as a leveling agent;

[0038] The preparation method of the coating composition comprises the following steps:

[0039] Step 1: Take parts by weight of acrylic resin emulsion, film-forming aid propylene glycol methyl ether, defoaming agent fatty alcohol polyoxyethylene ether and leveling agent sodium polyacrylate, pour them into a mixer, stir and mix evenly, let it stand to defoam, and form a premix;

[0040] Step 2: Stir and mix the curing agent aziridine with the premix in parts by weight to form a uniform material, and store it at room temperature.

[0041] The preparation method of the acrylic resin emulsion is specifically as follows:

[0042] Mix 10 parts of methyl methacrylate, 5 parts of ethyl acrylate, 1 part of acrylic acid, 2 parts of glycidyl methacrylate, 1 part of emulsifier sodium lauryl sulfate and 20 parts of purified water, stir evenly, increase the temperature to 80 ° C, continue to add 1 part of cross-linking agent and 2 parts of fluorine-containing silicone oil, add 0.1 part of initiator azobisisobutylamine hydrochloride, after the addition is complete, keep warm and stir for 6 hours, then cool and discharge.

[0043] The preparation method of the cross-linking agent specifically comprises the following steps:

[0044] Step 1: Mix 2.4 g of polyethylene glycol diglycidyl ether, 2 g of N,N-dimethyldodecylamine, and ethanol, stir evenly, pass nitrogen gas, raise the temperature to 65°C, stir for 3 h, add glacial acetic acid dropwise to adjust the pH to 7, continue stirring for 6 h, evaporate the solvent, remove the unreacted product, and obtain a cross-linked intermediate;

[0045] Step 2: Mix 1.6 g of the cross-linked intermediate, 0.55 g of isocyanoethyl methacrylate and toluene, stir evenly, introduce nitrogen, add 0.1 g of dibutyltin dilaurate, start stirring, stir at 70°C for 9 hours, evaporate the solvent, remove the unreacted products, cool and discharge the material to obtain a cross-linking agent.

[0046] The infrared test graph of the crosslinker is shown in Figure 1, where the peak at 3054 cm-1 is the CH stretching vibration peak in the carbon-carbon double bond, the peak at 2943 cm-1 is the CH stretching vibration peak in the methyl group, the peak at 2864 cm-1 is the CH stretching vibration peak in the methylene group, the peak at 1721 cm-1 is the C=O characteristic absorption peak in the amide group, the peak at 1409 cm-1 is the CN characteristic absorption peak in the quaternary ammonium salt functional group, and the COC characteristic absorption peak of the ether bond appears at 1165 cm-1.

[0047] The preparation method of fluorine-containing silicone oil is specifically as follows:

[0048] 1.8 g of hydroxyvinyl silicone oil with a vinyl content of 10% and a hydroxyl content of 8% was mixed with tetrahydrofuran and stirred until a uniform solution was formed. 0.26 g of trifluorobutyric acid, 0.4 g of dicyclohexylcarbodiimide and 0.1 g of 4-dimethylaminopyridine were added, nitrogen was passed through, and the mixture was stirred at room temperature for 6 h. The solvent was evaporated, the unreacted matter was removed, and the material was discharged to obtain fluorine-containing silicone oil.

[0049] The soap back titration method was used to test the ester group content in the fluorinated silicone oil structure. The test showed that the ester group content in the fluorinated silicone oil was 2.36 mmol / g. The ester group was caused by the esterification condensation reaction between the hydroxyl group in the hydroxyvinyl silicone oil structure and the carboxyl group in the trifluorobutyric acid structure. Example

[0050] A coating composition with mildew and antibacterial properties, comprising the following raw materials, by weight: 42 parts of acrylic resin emulsion, 3 parts of aziridine as a curing agent, 1.6 parts of ethylene glycol butyl ether as a film-forming aid, 1.5 parts of alkylphenol polyoxyethylene ether as a defoaming agent, and 0.3 parts of sodium polyacrylate as a leveling agent;

[0051] The preparation method of the coating composition comprises the following steps:

[0052] Step 1: Take parts by weight of acrylic resin emulsion, film-forming aid ethylene glycol butyl ether, defoaming agent alkylphenol polyoxyethylene ether and leveling agent sodium polyacrylate, pour them into a mixer, stir and mix evenly, let it stand to defoam, and form a premix;

[0053] Step 2: Stir and mix the curing agent aziridine with the premix in parts by weight to form a uniform material, and store it at room temperature.

[0054] The preparation method of the acrylic resin emulsion is specifically as follows:

[0055] Mix 20 parts of methyl methacrylate, 6 parts of ethyl acrylate, 2 parts of acrylic acid, 3 parts of glycidyl methacrylate, 1.5 parts of emulsifier sodium dodecylbenzenesulfonate and 25 parts of purified water, stir evenly, raise the temperature to 85°C, continue to add 2 parts of cross-linking agent and 5 parts of fluorine-containing silicone oil, add 0.2 parts of initiator azobiscyanovaleric acid, after the addition is complete, keep warm and stir for 8 hours, then cool and discharge.

[0056] The preparation methods of the cross-linking agent and the fluorinated silicone oil are the same as those in Example 1. Example

[0057] A coating composition with mildew and antibacterial properties, comprising the following raw materials, by weight: 45 parts of acrylic resin emulsion, 3 parts of aziridine as a curing agent, 2 parts of propylene glycol methyl ether as a film-forming aid, 2 parts of fatty alcohol polyoxyethylene ether as a defoaming agent, and 0.5 parts of sodium polyacrylate as a leveling agent;

[0058] The preparation method of the coating composition comprises the following steps:

[0059] Step 1: Take parts by weight of acrylic resin emulsion, film-forming aid propylene glycol methyl ether, defoaming agent fatty alcohol polyoxyethylene ether and leveling agent sodium polyacrylate, pour them into a mixer, stir and mix evenly, let it stand to defoam, and form a premix;

[0060] Step 2: Stir and mix the curing agent aziridine with the premix in parts by weight to form a uniform material, and store it at room temperature.

[0061] The preparation method of the acrylic resin emulsion is specifically as follows:

[0062] Mix 25 parts of methyl methacrylate, 15 parts of ethyl acrylate, 3 parts of acrylic acid, 3.5 parts of glycidyl methacrylate, 2 parts of emulsifier sodium lauryl sulfate and 35 parts of purified water, stir evenly, raise the temperature to 90°C, continue to add 2 parts of cross-linking agent and 6 parts of fluorine-containing silicone oil, add 0.3 parts of initiator azobisisobutylamine hydrochloride, after the addition is complete, keep warm and stir for 9 hours, then cool and discharge.

[0063] The preparation methods of the cross-linking agent and the fluorinated silicone oil are the same as those in Example 1.

[0064] Comparative Example 1

[0065] A coating composition, comprising the following raw materials, in parts by weight: 42 parts of acrylic resin emulsion, 3 parts of aziridine as a curing agent, 1.6 parts of ethylene glycol butyl ether as a film-forming aid, 1.5 parts of alkylphenol polyoxyethylene ether as a defoaming agent, and 0.3 parts of sodium polyacrylate as a leveling agent;

[0066] The preparation method of the coating composition comprises the following steps:

[0067] Step 1: Take parts by weight of acrylic resin emulsion, film-forming aid ethylene glycol butyl ether, defoaming agent alkylphenol polyoxyethylene ether and leveling agent sodium polyacrylate, pour them into a mixer, stir and mix evenly, let it stand to defoam, and form a premix;

[0068] Step 2: Stir and mix the curing agent aziridine with the premix in parts by weight to form a uniform material, and store it at room temperature.

[0069] The preparation method of the acrylic resin emulsion is specifically as follows:

[0070] Mix 20 parts of methyl methacrylate, 6 parts of ethyl acrylate, 2 parts of acrylic acid, 3 parts of glycidyl methacrylate, 1.5 parts of emulsifier sodium dodecylbenzenesulfonate and 25 parts of purified water, stir evenly, raise the temperature to 85°C, continue to add 5 parts of fluorinated silicone oil and mix, add 0.2 parts of initiator azobiscyanovaleric acid, after the addition is complete, keep warm and stir for 8 hours, then cool and discharge the material.

[0071] The preparation method of the fluorine-containing silicone oil is the same as that in Example 1.

[0072] Comparative Example 2

[0073] A coating composition, comprising the following raw materials, in parts by weight: 42 parts of acrylic resin emulsion, 3 parts of aziridine as a curing agent, 1.6 parts of ethylene glycol butyl ether as a film-forming aid, 1.5 parts of alkylphenol polyoxyethylene ether as a defoaming agent, and 0.3 parts of sodium polyacrylate as a leveling agent;

[0074] The preparation method of the coating composition comprises the following steps:

[0075] Step 1: Take parts by weight of acrylic resin emulsion, film-forming aid ethylene glycol butyl ether, defoaming agent alkylphenol polyoxyethylene ether and leveling agent sodium polyacrylate, pour them into a mixer, stir and mix evenly, let it stand to defoam, and form a premix;

[0076] Step 2: Stir and mix the curing agent aziridine with the premix in parts by weight to form a uniform material, and store it at room temperature.

[0077] The preparation method of the acrylic resin emulsion is specifically as follows:

[0078] Mix 20 parts of methyl methacrylate, 6 parts of ethyl acrylate, 2 parts of acrylic acid, 3 parts of glycidyl methacrylate, 1.5 parts of emulsifier sodium dodecylbenzenesulfonate and 25 parts of purified water, stir evenly, raise the temperature to 85°C, continue to add 2 parts of cross-linking agent and 5 parts of hydroxy vinyl silicone oil, add 0.2 parts of initiator azobiscyanovaleric acid, after the addition is complete, keep warm and stir for 8 hours, then cool and discharge.

[0079] The preparation method of the cross-linking agent is the same as that in Example 1.

[0080] Comparative Example 3

[0081] A coating composition, comprising the following raw materials, in parts by weight: 42 parts of acrylic resin emulsion, 3 parts of aziridine as a curing agent, 1.6 parts of ethylene glycol butyl ether as a film-forming aid, 1.5 parts of alkylphenol polyoxyethylene ether as a defoaming agent, and 0.3 parts of sodium polyacrylate as a leveling agent;

[0082] The preparation method of the coating composition comprises the following steps:

[0083] Step 1: Take parts by weight of acrylic resin emulsion, film-forming aid ethylene glycol butyl ether, defoaming agent alkylphenol polyoxyethylene ether and leveling agent sodium polyacrylate, pour them into a mixer, stir and mix evenly, let it stand to defoam, and form a premix;

[0084] Step 2: Stir and mix the curing agent aziridine with the premix in parts by weight to form a uniform material, and store it at room temperature.

[0085] The preparation method of the acrylic resin emulsion is specifically as follows:

[0086] Mix 20 parts of methyl methacrylate, 6 parts of ethyl acrylate, 2 parts of acrylic acid, 3 parts of glycidyl methacrylate, 1.5 parts of emulsifier sodium dodecylbenzenesulfonate and 25 parts of purified water, stir evenly, raise the temperature to 85°C, continue to add 2 parts of cross-linking agent and mix, add 0.2 parts of initiator azobiscyanovaleric acid, after the addition is complete, keep warm and stir for 8 hours, then cool and discharge.

[0087] The preparation method of the cross-linking agent is the same as that in Example 1.

[0088] Comparative Example 4

[0089] A coating composition, comprising the following raw materials, in parts by weight: 42 parts of acrylic resin emulsion, 3 parts of aziridine as a curing agent, 1.6 parts of ethylene glycol butyl ether as a film-forming aid, 1.5 parts of alkylphenol polyoxyethylene ether as a defoaming agent, and 0.3 parts of sodium polyacrylate as a leveling agent;

[0090] The preparation method of the coating composition comprises the following steps:

[0091] Step 1: Take parts by weight of acrylic resin emulsion, film-forming aid ethylene glycol butyl ether, defoaming agent alkylphenol polyoxyethylene ether and leveling agent sodium polyacrylate, pour them into a mixer, stir and mix evenly, let it stand to defoam, and form a premix;

[0092] Step 2: Stir and mix the curing agent aziridine with the premix in parts by weight to form a uniform material, and store it at room temperature.

[0093] The preparation method of the acrylic resin emulsion is specifically as follows:

[0094] Mix 20 parts of methyl methacrylate, 6 parts of ethyl acrylate, 2 parts of acrylic acid, 3 parts of glycidyl methacrylate, 1.5 parts of emulsifier sodium dodecylbenzenesulfonate and 25 parts of purified water, stir evenly, raise the temperature to 85°C, add 0.2 parts of initiator azobiscyanovaleric acid, after addition, keep warm and stir for 8 hours, then cool and discharge.

[0095] The coating compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 4 of the present invention were uniformly coated on the tinplate surface and dried and cured in an oven at 120° C. to form a coating film. After that, groups of experimental samples meeting the test specifications were prepared and the following performance tests were performed:

[0096] Adhesion tests were conducted with reference to the national standard GB / T 9286-2021. Bacterial inhibition tests were conducted with reference to the national standard GB / T 21866-2008, using Staphylococcus aureus as the test bacteria. Water contact angle tests were conducted using a PZ-200SD contact angle meter. The samples were placed in an oven at 180°C and removed after 24 hours to observe whether the coating film showed any signs of shedding, blistering, or yellowing. The heat resistance of the coating was evaluated, and the test results are recorded in the table below:

[0097] ;

[0098] As can be seen from the above table, the coatings prepared in Examples 1 to 3 of the present invention have strong adhesion, high antibacterial rate, good heat resistance, and water contact angles greater than 150°, and have super hydrophobic surfaces.

[0099] In the process of preparing the acrylic resin emulsion in Comparative Example 1, no crosslinking agent was used. Therefore, the prepared acrylic resin structure did not contain polyethylene glycol segments and gemini quaternary ammonium salt antibacterial groups, resulting in poor adhesion and antibacterial performance of the coating.

[0100] In the process of preparing the acrylic resin emulsion in Comparative Example 2, fluorine-free silicone oil was used to participate in the reaction. Only the silicone oil in the structure has hydrophobicity, and the water contact angle of the coating film is less than 150°. Therefore, the coating prepared in Comparative Example 2 does not meet the superhydrophobic requirement.

[0101] During the preparation of the acrylic resin emulsion in Comparative Example 3, silicone oil was not used to participate in the reaction, and the structure did not contain silicon-oxygen bonds and fluorine-containing hydrophobic segments. Therefore, the coating prepared in Comparative Example 3 had poor hydrophobicity and heat resistance.

[0102] During the preparation of the acrylic resin emulsion in Comparative Example 4, no crosslinking agent and silicone oil were used to participate in the polymerization reaction. The structure did not contain polyethylene glycol segments, gemini quaternary ammonium salt antibacterial groups, silicon-oxygen bonds, and fluorine-containing hydrophobic segments. Therefore, the coating prepared in Comparative Example 4 had the worst performance in all aspects.

[0103] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A coating composition having anti-mildew and antibacterial properties, characterized in that: By weight, it includes the following raw materials: 35-45 parts of acrylic resin emulsion, 2-3 parts of curing agent, 1.5-2 parts of film-forming aid, 1-2 parts of defoaming agent, 0.2-0.5 parts of leveling agent; The acrylic resin emulsion comprises the following raw materials in parts by weight: 10-25 parts of methyl methacrylate, 5-15 parts of ethyl acrylate, 1-3 parts of acrylic acid, 2-3.5 parts of glycidyl methacrylate, 1-2 parts of a crosslinking agent, 2-6 parts of fluorinated silicone oil, 0.1-0.3 parts of an initiator, 1-2 parts of an emulsifier, and 20-35 parts of purified water; The preparation method of the acrylic resin emulsion is specifically as follows: Mix parts by weight of methyl methacrylate, ethyl acrylate, acrylic acid, glycidyl methacrylate, emulsifier and purified water, stir evenly, raise the temperature to 80-90°C, continue to add parts by weight of crosslinking agent and fluorinated silicone oil, add initiator, after adding, keep warm and stir for 6-9 hours, cool and discharge; The cross-linking agent is a vinyl-terminated polyethylene glycol type cross-linking agent containing a gemini quaternary ammonium salt antibacterial functional group in its structure; The fluorine-containing silicone oil is a silicone oil derivative grafted with a fluorine-containing hydrophobic group.

2. The coating composition having mildew and antibacterial properties according to claim 1, characterized in that: The curing agent is aziridine; the film-forming aid is any one of propylene glycol methyl ether or ethylene glycol butyl ether; the defoaming agent is any one of fatty alcohol polyoxyethylene ether or alkylphenol polyoxyethylene ether; the leveling agent is sodium polyacrylate; the initiator is any one of azobisisobutylamine hydrochloride or azobiscyanovaleric acid; and the emulsifier is any one of sodium dodecyl sulfate or sodium dodecylbenzene sulfonate.

3. The coating composition having antifungal and antibacterial properties according to claim 1, characterized in that: The preparation method of the cross-linking agent specifically comprises the following steps: Step 1: Mix polyethylene glycol diglycidyl ether, tertiary amine monomer and ethanol, stir evenly, pass nitrogen protection, raise the temperature to 60-65°C, stir for 2-3 hours, add glacial acetic acid dropwise to adjust the pH value to 6-7, continue stirring for 6-8 hours, evaporate the solvent, remove the unreacted product, and obtain a cross-linked intermediate; Step 2: Mix the cross-linking intermediate, acrylic isocyanate and toluene, stir evenly, introduce nitrogen, add the catalyst, start stirring, stir at 70-75°C for 6-12h, evaporate the solvent, remove the unreacted product, cool and discharge the material to obtain the cross-linking agent.

4. The coating composition having mildew and antibacterial properties according to claim 3, characterized in that: In the first step, the tertiary amine monomer is any one of N,N-dimethylhexylamine, N,N-dimethyl-n-octylamine, N,N-dimethyldodecylamine or hexadecyldimethyl tertiary amine.

5. The coating composition having antifungal and antibacterial properties according to claim 3, characterized in that: In the second step, the acrylic isocyanate is any one of isocyanoethyl methacrylate or isocyanate ethyl acrylate.

6. The coating composition having antifungal and antibacterial properties according to claim 3, characterized in that: In the second step, the catalyst is any one of dibutyltin dilaurate or stannous octoate.

7. The coating composition having antifungal and antibacterial properties according to claim 1, characterized in that: The preparation method of the fluorine-containing silicone oil is specifically as follows: Hydroxyvinyl silicone oil and tetrahydrofuran are mixed and stirred to form a uniform solution, and fluorinated carboxylic acid, dicyclohexylcarbodiimide and 4-dimethylaminopyridine are added continuously, nitrogen is passed through, and after stirring at room temperature for 4-8 hours, the solvent is evaporated, the unreacted product is removed, and the material is discharged to obtain fluorinated silicone oil.

8. The coating composition having antifungal and antibacterial properties according to claim 7, characterized in that: The hydroxy vinyl silicone oil has a vinyl content of 10% and a hydroxyl content of 8%.

9. The coating composition having mildew and antibacterial properties according to claim 7, characterized in that: The fluorine-containing carboxylic acid is any one of trifluorobutyric acid and 5,5,5-trifluoropentanoic acid.

10. The method for preparing a coating composition having antifungal and antibacterial properties according to claim 1, characterized in that: The following steps are involved: Step 1: Take parts by weight of acrylic resin emulsion, film-forming aid, defoamer and leveling agent, pour them into a mixer, stir and mix them evenly, let them stand to defoam, and form a premix; Step 2: Mix the curing agent by weight with the premix to form a uniform material, and store it at room temperature.

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