Weather-resistant water-based latex colored paint and preparation method thereof

Abstract

The invention discloses weather-resistant water-based latex colored paint and a preparation method thereof, and belongs to the technical field of paint. The weather-resistant water-based latex colored paint comprises a component A and a component B, wherein the component A is prepared from the following raw material components in parts by weight: 100 parts by mass of epoxy composite emulsion, 0.5 to 0.8 part by mass of wetting dispersant, 0.2 to 0.4 part by mass of defoaming agent, 0.5 to 0.8 part by mass of flatting agent, 2 to 4 parts by mass of thickening agent, 40 to 50 parts by mass of pigment filler and 20 parts by mass of water; the epoxy composite emulsion is prepared from the following raw material components in parts by mass: 30 to 80 parts of branched epoxy resin, 20 to 70 parts of acrylate monomer, 2 to 3 parts of emulsifier and 1.4 to 1.6 parts of co-stabilizer; the acrylic monomer comprises perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, an azo acrylate monomer and acrylic acid; the azo acrylic monomer is obtained by reacting glycidyl methacrylate, 4, 4 '-dihydroxyazobenzene and p-chloromethyl benzoic acid; the branched epoxy resin is obtained by reaction of triethanolamine and epoxy resin.

Description

Technical Field

[0001] The invention relates to a weather-resistant water-based latex paint and a preparation method thereof. Background Art

[0002] With the increasing awareness of environmental protection and increasingly stringent laws and regulations on VOC (volatile organic compound) emissions, water-based paints have attracted widespread attention due to their low pollution and little impact on human health. Among the many water-based paints, water-based latex paints have been widely used in the field of interior and exterior wall decoration of buildings due to their good adhesion, scrub resistance and ease of construction.

[0003] However, despite the above advantages of water-based latex paint, its poor weather resistance has become one of the key factors restricting its wider use. Especially in outdoor environments with ultraviolet radiation and large changes in temperature and humidity, existing water-based latex paints are prone to problems such as powdering, fading, and cracking, which seriously affect the aesthetics and service life of buildings.

[0004] Therefore, the present invention provides a weather-resistant water-based latex paint and a preparation method thereof. Summary of the invention

[0005] The purpose of the present invention is to provide a weather-resistant water-based latex paint and a preparation method thereof, so as to solve the technical problems mentioned in the above background technology.

[0006] The technical solution for achieving the purpose of the present invention is:

[0007] A weather-resistant water-based latex paint comprises a component A and a component B. The raw material components of the component A comprise, by weight, 100 parts by weight of epoxy composite emulsion, 0.5-0.8 parts by weight of wetting dispersant, 0.2-0.4 parts by weight of defoamer, 0.5-0.8 parts by weight of leveling agent, 2-4 parts by weight of thickener, 40-50 parts by weight of pigment and filler, and 20 parts by weight of water; the raw material components of the component B comprise 28-32 parts by weight of water-based epoxy curing agent.

[0008] Furthermore, the raw material components of the epoxy composite emulsion include 30 to 80 parts by mass of branched epoxy resin, 20 to 70 parts by mass of acrylate monomer, 2 to 3 parts by mass of emulsifier, and 1.4 to 1.6 parts by mass of stabilizer.

[0009] Furthermore, the acrylic monomers include perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylate monomers, and acrylic acid.

[0010] Furthermore, the azo acrylic acid monomer is obtained by reacting glycidyl methacrylate, 4,4'-dihydroxyazobenzene and p-chloromethylbenzoic acid.

[0011] Furthermore, the branched epoxy resin is obtained by reacting triethanolamine and epoxy resin.

[0012] A method for preparing a weather-resistant water-based latex paint comprises the following preparation steps:

[0013] (1) Compounding according to the raw material components and their weight proportions as described in claim 1;

[0014] (2) The water, wetting dispersant and defoaming agent weighed in step (1) are placed in a container and stirred at 80 to 120 r / min until the wetting dispersant is dissolved; then, the pigment and filler are added while stirring at 80 to 120 r / min, and then dispersed at 1000 to 2000 r / min for 28 to 32 min, and then the stirring speed is adjusted to 80 to 120 r / min. While stirring, epoxy emulsion, thickener and leveling agent are added in sequence, and then stirred and dispersed at 300 to 500 r / min for 10 to 20 min to obtain component A, which is stored for later use;

[0015] (3) After mixing component A and component B, stir and mix at 400-800 r / min for 20-40 min, let stand for 30 min, and then use air spray to cover the coating on the surface of the substrate, and then cure at room temperature for 7 days, spray acetonitrile on the surface, and then irradiate under 365 nm ultraviolet light for 18-22 min, and continue to cure at 60-90° C. for 3-5 h to obtain a weather-resistant water-based latex paint layer with a thickness of 40-50 μm.

[0016] Furthermore, the preparation steps of the epoxy composite emulsion are as follows: dissolving the branched epoxy resin in perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylic acid monomer, acrylic acid, and hexadecane, and then stirring at 300-400 rpm for 8-12 minutes at room temperature, adding an oxidizing initiator and continuing to stir for 8-12 minutes, then adding an aqueous solution of an emulsifier and stirring at 450-550 rpm for 25-35 minutes, and then shearing at 1400-1600 rpm for 14-16 minutes, and high-pressure homogenizing 2-4 times at 80 MPa using a high-pressure homogenizer to obtain a pre-emulsion; mixing 25% of the pre-emulsion and 25% of the reducing agent The initiators are mixed, the temperature is raised to 58-62° C., and the remaining 75% of the pre-emulsion and 75% of the reducing initiator are added separately using a peristaltic pump, and the addition is completed within 55-65 minutes. Subsequently, under nitrogen protection, polymerization reaction is carried out at 58-62° C. for 4-6 hours to obtain an epoxy composite emulsion; wherein, the ratio of the emulsifier to the aqueous solution in the emulsifier is 2-3:100; the oxidizing initiator is di-tert-butyl peroxide, and the amount is 2%; the reducing oxidant is FF6M, and the amount is 2%; the molar ratio of perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylic acid monomer, and acrylic acid is 7-9:14-16:8-12:7-9:1.

[0017] Furthermore, the preparation steps of the branched epoxy resin are as follows: under nitrogen protection, triethanolamine, epoxy resin, and catalyst tetrabutylammonium bromide are mixed, then the temperature is raised to 78-82°C, reacted for 3.5-4.5 hours, cooled to room temperature after the reaction is completed, tetrahydrofuran (200 times the mass of triethanolamine) is added and stirred to dissolve, and then deionized water (500 times the mass of triethanolamine) at 68-72°C is added and mixed, and the mixture is allowed to stand for stratification to remove the upper layer of liquid to remove the catalyst and small molecular products, and the steps of hot water washing, standing for stratification, and removing the upper layer of liquid are repeated in sequence for 2-4 times, and dried to obtain a branched epoxy resin; wherein the molar ratio of the hydroxyl group of triethanolamine to the epoxy group in the epoxy resin is 1:2.5-3.5; and the amount of the catalyst tetrabutylammonium bromide is 4.5%-5%.

[0018] Furthermore, the preparation steps of the azo acrylic acid monomer are as follows: under nitrogen protection, 4,4'-dihydroxyazobenzene, glycidyl methacrylate, and catalyst tetrabutylammonium bromide are mixed, then the temperature is raised to 78-82°C, and the reaction is carried out for 3.5-4.5 hours. After the reaction is completed, the mixture is cooled to room temperature, tetrahydrofuran (200 times the mass of 4,4'-dihydroxyazobenzene) is added and stirred to dissolve, and deionized water (500 times the mass of 4,4'-dihydroxyazobenzene) and 68-72°C are added and mixed, and the upper layer of liquid is removed to remove the catalyst and small molecular products by standing and stratifying, and the heat treatment is repeated in sequence. The steps of washing with water, standing for stratification, and removing the upper layer of liquid are repeated 2 to 4 times, and drying is performed to obtain an intermediate product a; the intermediate product a, p-chloromethylbenzoic acid, phosphorus oxychloride, anhydrous zinc chloride, and solvent sulfolane are stirred and mixed, and then heated to 70 to 75° C., and kept warm for reaction for 1.8 to 2.2 hours, and then deionized water is added at a rate of 10 mL / min, stirred for 25 to 30 minutes, and cold water 24 to 26 times the mass of phosphorus oxychloride is poured in, and stirring is continued for 10 to 20 minutes. After standing for 25 to 35 minutes, the mixture is cooled to below 20° C., filtered, washed with water, and dried to obtain an azo acrylic acid monomer.

[0019] Furthermore, the molar ratio of 4'-dihydroxyazobenzene to glycidyl methacrylate is 1:0.8-1.2; the dosage of the catalyst tetrabutylammonium bromide is 4.5%-5%; the molar ratio of the intermediate product a, p-chloromethylbenzoic acid, phosphorus oxychloride, and anhydrous zinc chloride is 0.113-0.115:0.109-0.111:0.18-0.22:0.14-0.16; and the mass ratio of the solvent sulfolane, deionized water, and phosphorus oxychloride is 0.62-0.64:2.5-3.5:1.

[0020] By adopting the above technical solution, the present invention has the following beneficial effects:

[0021] The weather-resistant water-based latex paint of the present invention comprises component A and component B, wherein the raw material components of component A comprise: epoxy composite emulsion, wetting dispersant, defoamer, leveling agent, thickener, pigment and filler, and water; the raw material components of component B comprise water-based epoxy curing agent; the raw material components of epoxy composite emulsion comprise branched epoxy resin, acrylate monomer, emulsifier, and stabilizer; the branched epoxy resin is obtained by reaction of triethanolamine and epoxy resin; the acrylic acid monomer comprises perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylic acid monomer, and acrylic acid; the azo acrylic acid monomer is obtained by reaction of glycidyl methacrylate, 4,4'-dihydroxyazobenzene, and p-chloromethylbenzoic acid.

[0022] First, the hydroxyl groups on the triethanolamine react and graft with the epoxy groups on the epoxy resin to form a branched structure epoxy resin with triethanolamine as the branching center, which effectively improves the problems of high toughness and brittleness of traditional linear epoxy resins and increases the impact resistance of weather-resistant water-based latex paint.

[0023] Secondly, the azo acrylic acid monomer is obtained by reacting glycidyl methacrylate, 4,4'-dihydroxyazobenzene and p-chloromethylbenzoic acid; compared with directly adding a benzophenone type UV absorber, the present application forms an o-hydroxybenzophenone type UV absorber by reacting the epoxy group on glycidyl methacrylate with the hydroxyl group on 4,4'-dihydroxyazobenzene, and p-chloromethylbenzoic acid is grafted onto the benzene ring on 4,4'-dihydroxyazobenzene through benzoic acid. When preparing the epoxy composite emulsion later, the azo acrylic acid monomer is copolymerized and grafted with perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylic acid monomer and acrylic acid to form an acrylic acid copolymer with a comb-like structure, and acrylic acid is grafted with a branched epoxy resin through a carboxyl group to form a branched comb-like three-dimensional cross-linked network, so that the UV absorber is firmly grafted onto the resin base material, thereby ensuring the weathering stability of the weather-resistant water-based latex paint.

[0024] Finally, the weather-resistant water-based latex paint is applied to the surface of the substrate and cured for a period of time, then sprayed with acetonitrile and exposed to light for a period of time for thermal curing. During this period, the azobenzene on the surface of the weather-resistant water-based latex paint coating is isomerized and folded under light, thereby shortening the molecular chain length of the azo acrylic monomer in the comb-like structure, exposing the long-chain perfluorodecyl acrylate to the surface, and increasing the waterproof performance of the weather-resistant water-based latex paint; at the same time, the halogenated alkanes on the azo acrylic monomer penetrate into the polymer network after the azobenzene isomerizes and folds, and react with the tertiary amine on the branched epoxy resin to form a quaternary ammonium salt, which gives the weather-resistant water-based latex paint coating antibacterial properties. DETAILED DESCRIPTION

[0025] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with specific implementation methods.

[0026] The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention.

[0027] Some of the raw material components of the embodiments of the present invention and the comparative examples are as follows:

[0028] The defoamer was obtained from Serdas7015 of Shengwo, the Netherlands;

[0029] The pigment and filler are mixed with red iron oxide, zinc phosphate, wollastonite powder and mica powder in a mass ratio of 3:2:2:2;

[0030] The wetting and dispersing agent was Nuosperse FA 182 from Shengwo, the Netherlands;

[0031] The leveling agent is Tego Glide440 from Germany;

[0032] The thickener is VT-819 from Detron, Germany;

[0033] The emulsifier is sodium dodecyl sulfate;

[0034] Hexadecane is used as the auxiliary stabilizer;

[0035] Epoxy resin: bisphenol A epoxy resin E51, industrial pure, epoxy value 0.52 mol / 100g;

[0036] The curing agent used is HGF-100 produced by Zhejiang Anbang Company.

[0037] (Example 1)

[0038] A method for preparing a weather-resistant water-based latex paint comprises the following preparation steps:

[0039] (1) The following raw material components and their weight proportions are prepared: 100 parts by weight of epoxy composite emulsion, 0.5 parts by weight of wetting and dispersing agent, 0.2 parts by weight of defoaming agent, 0.5 parts by weight of leveling agent, 2 parts by weight of thickener, 40 parts by weight of pigment and filler, 20 parts by weight of water, and 28 parts by weight of water-based epoxy curing agent;

[0040] (2) The water, wetting dispersant and defoaming agent weighed in step (1) are placed in a container and stirred at 80 r / min until the wetting dispersant is dissolved; then, the pigment and filler are added while stirring at 80 r / min, and then dispersed at 1000 r / min for 28 min, and then the stirring speed is adjusted to 80 r / min. While stirring, epoxy emulsion, thickener and leveling agent are added in sequence, and then stirred and dispersed at 300 r / min for 10 min to obtain component A, which is stored for later use;

[0041] (3) After mixing component A and component B, stir and mix at 400 r / min for 20 minutes, let stand for 30 minutes, and then use air spray to cover the coating on the surface of the substrate, and then cure at room temperature for 7 days. Spray acetonitrile on the surface, and then irradiate under 365nm ultraviolet light for 18 minutes, and continue to cure at 60°C for 3 hours to obtain a weather-resistant water-based latex paint layer with a thickness of 40 μm.

[0042] The preparation steps of the epoxy composite emulsion are as follows: dissolving the branched epoxy resin in perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylic acid monomer, acrylic acid, and hexadecane, stirring at 300 rpm for 8 minutes at room temperature, adding an oxidizing initiator and continuing to stir for 8 minutes, then adding an aqueous solution of an emulsifier and stirring at 450 rpm for 25 minutes, shearing at 1400 rpm for 14 minutes, and high-pressure homogenizing twice at 80 MPa using a high-pressure homogenizer to obtain a pre-emulsion; mixing 25% of the pre-emulsion and 25% of the reducing initiator, heating to 58° C., and using a peristaltic pump to add the remaining 75% of the pre-emulsion respectively. and 75% reducing initiator, the addition was completed within 55 minutes, and then polymerization reaction was carried out at 58°C for 4 hours under nitrogen protection to obtain an epoxy composite emulsion; wherein, the ratio of the emulsifier to the aqueous solution in the emulsifier was 2:100; the oxidizing initiator was di-tert-butyl peroxide, and the amount was 2%; the reducing oxidant was FF6M, and the amount was 2%; 30 parts by mass of branched epoxy resin, 20 parts by mass of acrylate monomer, 2 parts by mass of emulsifier, and 1.4 parts by mass of stabilizer, wherein the molar ratio of perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylic acid monomer, and acrylic acid in the acrylate monomer was 7:14:8:7:1.

[0043] The preparation steps of the branched epoxy resin are as follows: under nitrogen protection, triethanolamine, epoxy resin and catalyst tetrabutylammonium bromide are mixed, then the temperature is raised to 78°C, reacted for 3.5 hours, cooled to room temperature after the reaction is completed, tetrahydrofuran with a mass of 200 times that of triethanolamine is added and stirred to dissolve, deionized water with a mass of 500 times that of triethanolamine and a temperature of 68°C is added and mixed, the mixture is allowed to stand for stratification and the upper layer liquid is removed to remove the catalyst and small molecular products, the steps of hot water washing, standing for stratification and removing the upper layer liquid are repeated twice in sequence, and the mixture is dried to obtain the branched epoxy resin; wherein the molar ratio of the hydroxyl group of the triethanolamine to the epoxy group in the epoxy resin is 1:2.5; and the amount of the catalyst tetrabutylammonium bromide is 4.5%.

[0044] The preparation steps of the azo acrylic acid monomer are as follows: under nitrogen protection, 4,4'-dihydroxyazobenzene, glycidyl methacrylate, and catalyst tetrabutylammonium bromide are mixed, then the temperature is raised to 78°C, reacted for 3.5 hours, cooled to room temperature after the reaction is completed, tetrahydrofuran (200 times the mass of 4,4'-dihydroxyazobenzene) is added and stirred to dissolve, deionized water (500 times the mass of 4,4'-dihydroxyazobenzene) is added and mixed at 68°C, the upper layer liquid is removed by standing and stratification to remove the catalyst and small molecular products, the steps of hot water washing, standing and stratification, and removing the upper layer liquid are repeated twice in sequence, and dried to obtain an intermediate product a; the intermediate product a, p-chloromethylbenzoic acid, phosphorus oxychloride, anhydrous zinc chloride, and solvent sulfolane are stirred and mixed, and then The mixture was heated to 70°C, kept warm for 1.8 hours, and then deionized water was added at a rate of 10 mL / min, stirred for 25 minutes, and cold water 24 times the mass of phosphorus oxychloride was poured in. The mixture was stirred for 10 minutes, and allowed to stand for 25 minutes, and then cooled to below 20°C, filtered, washed, and dried to obtain an azo acrylic acid monomer; wherein the molar ratio of 4'-dihydroxyazobenzene to glycidyl methacrylate was 1:0.8-1.2; the amount of catalyst tetrabutylammonium bromide was 4.5%-5%; the molar ratio of intermediate product a, p-chloromethylbenzoic acid, phosphorus oxychloride, and anhydrous zinc chloride was 0.113:0.109:0.18:0.14; and the mass ratio of solvent sulfolane, deionized water, and phosphorus oxychloride was 0.62:2.5:1.

[0045] (Example 2)

[0046] A method for preparing a weather-resistant water-based latex paint comprises the following preparation steps:

[0047] (1) The following raw material components and their weight proportions are prepared: 100 parts by weight of epoxy composite emulsion, 0.7 parts by weight of wetting and dispersing agent, 0.3 parts by weight of defoaming agent, 0.7 parts by weight of leveling agent, 3 parts by weight of thickener, 45 parts by weight of pigment and filler, 20 parts by weight of water, and 30 parts by weight of water-based epoxy curing agent;

[0048] (2) The water, wetting dispersant and defoaming agent weighed in step (1) are placed in a container and stirred at 100 r / min until the wetting dispersant is dissolved; then, the pigment and filler are added while stirring at 100 r / min, and then dispersed at 1500 r / min for 30 min, and then the stirring speed is adjusted to 100 r / min. While stirring, epoxy emulsion, thickener and leveling agent are added in sequence, and then stirred and dispersed at 400 r / min for 15 min to obtain component A, which is stored for later use;

[0049] (3) After mixing component A and component B, stir and mix at 600 r / min for 30 minutes, let stand for 30 minutes, and then use air spray to cover the coating on the surface of the substrate, and then cure at room temperature for 7 days. Spray acetonitrile on the surface, and then irradiate under 365nm ultraviolet light for 20 minutes, and continue to cure at 75°C for 4 hours to obtain a weather-resistant water-based latex paint layer with a thickness of 45 μm.

[0050] The preparation steps of the epoxy composite emulsion are as follows: dissolving the branched epoxy resin in perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylic acid monomer, acrylic acid, and hexadecane, stirring at 350 rpm for 10 minutes at room temperature, adding an oxidizing initiator and continuing to stir for 10 minutes, then adding an aqueous solution of an emulsifier and stirring at 500 rpm for 30 minutes, shearing at 1500 rpm for 15 minutes, and high-pressure homogenizing at 80 MPa for 3 times using a high-pressure homogenizer to obtain a pre-emulsion; mixing 25% of the pre-emulsion and 25% of the reducing initiator, heating to 60° C., and using a peristaltic pump to add the remaining 75% of the pre-emulsion and 75% reducing initiator is added dropwise within 60 minutes, and then polymerization reaction is carried out at 60°C for 5 hours under nitrogen protection to obtain epoxy composite emulsion; wherein, the ratio of emulsifier to aqueous solution in the aqueous solution of emulsifier is 2.5100; the oxidizing initiator is di-tert-butyl peroxide, and the amount is 2%; the reducing oxidant is FF6M, and the amount is 2%; 55 parts by weight of branched epoxy resin, 45 parts by weight of acrylate monomer, 2.5 parts by weight of emulsifier, and 1.5 parts by weight of stabilizer, wherein the molar ratio of perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylic acid monomer, and acrylic acid in the acrylate monomer is 8:15:10:8:1.

[0051] The preparation steps of the branched epoxy resin are as follows: under nitrogen protection, triethanolamine, epoxy resin and catalyst tetrabutylammonium bromide are mixed, then the temperature is raised to 80°C, reacted for 4 hours, cooled to room temperature after the reaction is completed, tetrahydrofuran with a mass of 200 times that of triethanolamine is added and stirred to dissolve, deionized water with a mass of 500 times that of triethanolamine and a temperature of 70°C is added and mixed, the upper layer liquid is removed by standing and stratification to remove the catalyst and small molecular products, the steps of hot water washing, standing and stratification and removing the upper layer liquid are repeated three times in sequence, and dried to obtain the branched epoxy resin; wherein the molar ratio of the hydroxyl group of the triethanolamine to the epoxy group in the epoxy resin is 1:3; and the amount of the catalyst tetrabutylammonium bromide is 4.8%.

[0052] The preparation steps of the azo acrylic acid monomer are as follows: under nitrogen protection, 4,4'-dihydroxyazobenzene, glycidyl methacrylate, and catalyst tetrabutylammonium bromide are mixed, then the temperature is raised to 80°C, reacted for 4 hours, cooled to room temperature after the reaction is completed, tetrahydrofuran (200 times the mass of 4,4'-dihydroxyazobenzene) is added, stirred and dissolved, deionized water (500 times the mass of 4,4'-dihydroxyazobenzene) is added and mixed at 70°C, the upper layer liquid is removed by standing and stratification to remove the catalyst and small molecular products, the steps of hot water washing, standing and stratification, and removing the upper layer liquid are repeated 2 to 4 times in sequence, and dried to obtain an intermediate product a; the intermediate product a, p-chloromethylbenzoic acid, phosphorus oxychloride, anhydrous zinc chloride, and solvent sulfolane are stirred and mixed; The mixture was combined, and then heated to 73°C, kept warm for reaction for 2h, and then deionized water was added at a rate of 10mL / min, stirred for 28min, and cold water 25 times the mass of phosphorus oxychloride was poured in, and the mixture was stirred for 15min and allowed to stand for 30min, then cooled to below 20°C, filtered, washed with water, and dried to obtain an azo acrylic acid monomer; wherein the molar ratio of 4'-dihydroxyazobenzene to glycidyl methacrylate was 1:0.8-1.2; the amount of catalyst tetrabutylammonium bromide was 4.8%; the molar ratio of intermediate product a, p-chloromethylbenzoic acid, phosphorus oxychloride, and anhydrous zinc chloride was 0.114:0.110:0.20:0.15; and the mass ratio of solvent sulfolane, deionized water, and phosphorus oxychloride was 0.63:3:1.

[0053] (Example 3)

[0054] A method for preparing a weather-resistant water-based latex paint comprises the following preparation steps:

[0055] (1) The following raw material components and their weight proportions are prepared: 100 parts by weight of epoxy composite emulsion, 0.8 parts by weight of wetting and dispersing agent, 0.4 parts by weight of defoaming agent, 0.8 parts by weight of leveling agent, 4 parts by weight of thickener, 50 parts by weight of pigment and filler, 20 parts by weight of water, and 32 parts by weight of water-based epoxy curing agent;

[0056] (2) The water, wetting dispersant and defoaming agent weighed in step (1) are placed in a container and stirred at 120 r / min until the wetting dispersant is dissolved; then, the pigment and filler are added while stirring at 120 r / min, and then dispersed at 2000 r / min for 32 min, and then the stirring speed is adjusted to 120 r / min, and while stirring, epoxy emulsion, thickener and leveling agent are added in sequence, and then stirred and dispersed at 500 r / min for 20 min to obtain component A, which is stored for later use;

[0057] (3) After mixing component A and component B, stir and mix at 800 r / min for 40 minutes, let stand for 30 minutes, and then use air spray to cover the coating on the surface of the substrate, and then cure at room temperature for 7 days. Spray acetonitrile on the surface, and then irradiate under 365nm ultraviolet light for 22 minutes, and continue to cure at 90°C for 5 hours to obtain a weather-resistant water-based latex paint layer with a thickness of 50 μm.

[0058] The preparation steps of the epoxy composite emulsion are as follows: dissolving a branched epoxy resin in perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylic acid monomer, acrylic acid, and hexadecane, stirring at 400 rpm for 12 minutes at room temperature, adding an oxidizing initiator and continuing to stir for 12 minutes, then adding an aqueous solution of an emulsifier and stirring at 550 rpm for 35 minutes, shearing at 1600 rpm for 16 minutes, and high-pressure homogenizing at 80 MPa for 4 times using a high-pressure homogenizer to obtain a pre-emulsified liquid; mixing 25% of the pre-emulsified liquid and 25% of the reducing initiator, heating to 62° C., and using a peristaltic pump to add the remaining 75% of the pre-emulsified liquid and 25% of the reducing initiator, respectively; liquid and 75% reducing initiator, and the addition is completed within 65 minutes, and then polymerization reaction is carried out at 62°C for 6 hours under nitrogen protection to obtain an epoxy composite emulsion; wherein, the ratio of emulsifier to aqueous solution in the aqueous solution of the emulsifier is 3:100; the oxidizing initiator is di-tert-butyl peroxide, and the amount is 2%; the reducing oxidant is FF6M, and the amount is 2%; 80 parts by weight of branched epoxy resin, 70 parts by weight of acrylate monomer, 3 parts by weight of emulsifier, and 1.6 parts by weight of stabilizer, wherein the molar ratio of perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylic acid monomer, and acrylic acid in the acrylate monomer is 9:16:12:9:1.

[0059] The preparation steps of the branched epoxy resin are as follows: under nitrogen protection, triethanolamine, epoxy resin and catalyst tetrabutylammonium bromide are mixed, then the temperature is raised to 82°C, reacted for 4.5 hours, cooled to room temperature after the reaction is completed, tetrahydrofuran with a mass of 200 times that of triethanolamine is added and stirred to dissolve, deionized water with a mass of 500 times that of triethanolamine and a temperature of 72°C is added and mixed, the mixture is allowed to stand for stratification and the upper layer liquid is removed to remove the catalyst and small molecular products, the steps of hot water washing, standing for stratification and removing the upper layer liquid are repeated in sequence for 4 times, and dried to obtain the branched epoxy resin; wherein the molar ratio of the hydroxyl group of the triethanolamine to the epoxy group in the epoxy resin is 1:3.5; and the amount of the catalyst tetrabutylammonium bromide is 5%.

[0060] The preparation steps of the azo acrylic acid monomer are as follows: under nitrogen protection, 4,4'-dihydroxyazobenzene, glycidyl methacrylate, and catalyst tetrabutylammonium bromide are mixed, then the temperature is raised to 82°C, reacted for 4.5 hours, cooled to room temperature after the reaction is completed, tetrahydrofuran (200 times the mass of 4,4'-dihydroxyazobenzene) is added and stirred to dissolve, deionized water (500 times the mass of 4,4'-dihydroxyazobenzene) is added and mixed at 72°C, the upper layer liquid is removed by standing and stratification to remove the catalyst and small molecular products, the steps of hot water washing, standing and stratification, and removing the upper layer liquid are repeated 4 times in sequence, and dried to obtain an intermediate product a; the intermediate product a, p-chloromethylbenzoic acid, phosphorus oxychloride, anhydrous zinc chloride, and solvent sulfolane are stirred and mixed, and then The mixture was heated to 75°C, kept warm for 2.2 hours, and then deionized water was added at a rate of 10 mL / min, stirred for 30 minutes, and cold water 26 times the mass of phosphorus oxychloride was poured in. The mixture was stirred for 20 minutes, and allowed to stand for 35 minutes, and then cooled to below 20°C, filtered, washed, and dried to obtain an azo acrylic acid monomer; wherein the molar ratio of 4'-dihydroxyazobenzene to glycidyl methacrylate was 1:0.8-1.2; the amount of catalyst tetrabutylammonium bromide was 4.5%-5%; the molar ratio of intermediate product a, p-chloromethylbenzoic acid, phosphorus oxychloride, and anhydrous zinc chloride was 0.115:0.111:0.22:0.16; and the mass ratio of solvent sulfolane, deionized water, and phosphorus oxychloride was 0.64:3.5:1.

[0061] (Comparative Example 1)

[0062] The difference between Comparative Example 1 and Example 2 is that the acrylic monomers only use perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, and acrylic acid; the remaining steps and ingredients are the same as those in Example 2.

[0063] (Comparative Example 2)

[0064] The difference between Comparative Example 2 and Example 2 is that the acrylic monomers only use methyl methacrylate, butyl methacrylate, azo acrylate monomers, and acrylic acid; the remaining steps and ingredients are the same as those of Example 2.

[0065] (Comparative Example 3)

[0066] The difference between Comparative Example 3 and Example 2 is that the azo acrylic acid monomer is obtained only by reacting glycidyl methacrylate and 4,4'-dihydroxyazobenzene; the remaining steps and components are the same as those in Example 2.

[0067] (Comparative Example 4)

[0068] The difference between Comparative Example 4 and Example 2 is that the raw material components of the epoxy composite emulsion use epoxy resin, acrylate monomer, emulsifier, and stabilizer, and the remaining steps and ingredients are the same as those of Example 2.

[0069] (Comparative Example 5)

[0070] The difference between Comparative Example 5 and Example 2 is that in step (3), the weather-resistant water-based latex paint is applied to the surface of the substrate and cured for a period of time to obtain a weather-resistant water-based latex paint layer. The remaining steps and components are the same as those in Example 2.

[0071] Effect example:

[0072] Impact resistance: The impact resistance of the weather-resistant water-based latex paint layer prepared in the test examples and comparative examples was tested with reference to GB / T1732.

[0073] Waterproofness: The contact angle of the weather-resistant water-based latex paint layer prepared in the embodiment and the comparative example was measured using a JC2000DM contact angle measuring instrument produced by Shanghai Zhongchen Digital Technology Equipment Co., Ltd., and 2 μL of deionized water was used each time for the test.

[0074] Weather resistance: refer to GB / T 11186.2 to test the color difference value of the weather-resistant water-based latex paint layer prepared in the examples and comparative examples after UV aging for 1000 hours.

[0075] Antibacterial property: The antibacterial property of the weather-resistant water-based latex paint layer prepared in the test examples and comparative examples was tested with reference to GB / T21866.

[0076] Table 1 below shows the performance test results of the weather-resistant water-based latex paints prepared in the examples and comparative examples:

[0077] Table 1

[0078]

[0079] It can be seen from Table 1 above that the weather-resistant water-based latex paints prepared in Examples 1 to 3 have strong waterproofness, weather resistance, impact resistance and antibacterial properties.

[0080] Comparative Example 1 is compared with Example 2. The acrylic monomer in Comparative Example 1 does not use an azo acrylic monomer, and the waterproofness, weather resistance and antibacterial properties of the obtained weather-resistant water-based latex paint are relatively weak.

[0081] Comparative Example 2 is compared with Example 2. In Comparative Example 2, the acrylic monomer does not use perfluorodecyl acrylate, and the waterproofness of the obtained weather-resistant water-based latex paint is weaker than that of Example 2.

[0082] Comparative Example 3 is compared with Example 2. The azo acrylic monomer in Comparative Example 3 is obtained only by reacting glycidyl methacrylate and 4,4'-dihydroxyazobenzene. The weather resistance and antibacterial properties of the obtained weather-resistant water-based latex paint are weaker than those in Example 2.

[0083] Compared with Example 2, in Comparative Example 4, the raw material component of the epoxy composite emulsion of Comparative Example 4 only uses epoxy resin, and the antibacterial property and impact resistance of the obtained weather-resistant water-based latex paint are weaker than those of Example 2.

[0084] Compared with Example 2, the weather-resistant water-based latex paint of Comparative Example 5 is applied to the surface of the substrate and cured for a period of time to obtain a weather-resistant water-based latex paint layer. The waterproofness and antibacterial properties of the obtained weather-resistant water-based latex paint are weaker than those of Example 2.

[0085] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific 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 should be included in the protection scope of the present invention.

Claims

1. A weather-resistant water-based latex paint, characterized in that: It includes component A and component B; In terms of weight, the raw material components of component A include: 100 parts by weight of epoxy composite emulsion, 0.5-0.8 parts by weight of wetting and dispersing agent, 0.2-0.4 parts by weight of defoaming agent, 0.5-0.8 parts by weight of leveling agent, 2-4 parts by weight of thickener, 40-50 parts by weight of pigment and filler, and 20 parts by weight of water; the raw material components of component B include 28-32 parts by weight of water-based epoxy curing agent.

2. The weather-resistant water-based latex paint according to claim 1, characterized in that: The raw material components of the epoxy composite emulsion include 30-80 parts by weight of branched epoxy resin, 20-70 parts by weight of acrylate monomer, 2-3 parts by weight of emulsifier, and 1.4-1.6 parts by weight of auxiliary stabilizer.

3. The weather-resistant water-based latex paint according to claim 2, characterized in that: The acrylic monomers include perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylate monomers, and acrylic acid.

4. The weather-resistant water-based latex paint according to claim 2, characterized in that: The azo acrylic acid monomer is obtained by reacting glycidyl methacrylate, 4,4'-dihydroxyazobenzene and p-chloromethylbenzoic acid.

5. The weather-resistant water-based latex paint according to claim 2, characterized in that: The branched epoxy resin is obtained by reacting triethanolamine and epoxy resin.

6. A method for preparing a weather-resistant water-based latex paint, characterized in that: The method comprises the following preparation steps: (1) Compounding according to the raw material components and their weight proportions as described in claim 1; (2) The water, wetting dispersant and defoaming agent weighed in step (1) are placed in a container and stirred at 80 to 120 r / min until the wetting dispersant is dissolved; then, the pigment and filler are added while stirring at 80 to 120 r / min, and then dispersed at 1000 to 2000 r / min for 28 to 32 min, and then the stirring speed is adjusted to 80 to 120 r / min. While stirring, epoxy emulsion, thickener and leveling agent are added in sequence, and then stirred and dispersed at 300 to 500 r / min for 10 to 20 min to obtain component A, which is stored for later use; (3) After mixing component A and component B, stir and mix at 400-800 r / min for 20-40 min, let stand for 30 min, and then use air spray to cover the coating on the surface of the substrate, and then cure at room temperature for 7 days, spray acetonitrile on the surface, and then irradiate under 365 nm ultraviolet light for 18-22 min, and continue to cure at 60-90° C. for 3-5 h to obtain a weather-resistant water-based latex paint layer with a thickness of 40-50 μm.

7. The method for preparing the weather-resistant water-based latex paint according to claim 6, characterized in that: The preparation steps of the epoxy composite emulsion are as follows: dissolving a branched epoxy resin in perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylic acid monomer, acrylic acid, and hexadecane, stirring at 300-400 rpm for 8-12 minutes at room temperature, adding an oxidative initiator and continuing to stir for 8-12 minutes, then adding an aqueous solution of an emulsifier and stirring at 450-550 rpm for 25-35 minutes, shearing at 1400-1600 rpm for 14-16 minutes, and high-pressure homogenizing at 80 MPa for 2-4 times using a high-pressure homogenizer to obtain a pre-emulsion; adding 25% The pre-emulsion and 25% reducing initiator are mixed, heated to 58-62°C, and the remaining 75% pre-emulsion and 75% reducing initiator are added by a peristaltic pump respectively, and the addition is completed within 55-65 minutes. Subsequently, under nitrogen protection, polymerization reaction is carried out at 58-62°C for 4-6 hours to obtain an epoxy composite emulsion; wherein the oxidizing initiator is di-tert-butyl peroxide, and the amount is 2%; the reducing oxidant is FF6M, and the amount is 2%; the molar ratio of perfluorodecyl acrylate, methyl methacrylate, butyl methacrylate, azo acrylic acid monomer, and acrylic acid is 7-9:14-16:8-12:7-9:

1.

8. The method for preparing the weather-resistant water-based latex paint according to claim 7, characterized in that: The preparation steps of the branched epoxy resin are as follows: under nitrogen protection, triethanolamine, epoxy resin and catalyst tetrabutylammonium bromide are mixed, then the temperature is raised to 78-82°C, reacted for 3.5-4.5h, cooled to room temperature after the reaction is completed, tetrahydrofuran with a mass of 200 times that of triethanolamine is added and stirred to dissolve, deionized water with a mass of 500 times that of triethanolamine and a temperature of 68-72°C is added and mixed, the mixture is allowed to stand for stratification and the upper layer liquid is removed to remove the catalyst and small molecular products, the steps of hot water washing, standing for stratification and removing the upper layer liquid are repeated 2-4 times in sequence, and dried to obtain the branched epoxy resin; wherein the molar ratio of the hydroxyl group of the triethanolamine to the epoxy group in the epoxy resin is 1:2.5-3.5; and the amount of the catalyst tetrabutylammonium bromide is 4.5%-5%.

9. The method for preparing the weather-resistant water-based latex paint according to claim 7, characterized in that: The preparation steps of the azo acrylic acid monomer are as follows: under nitrogen protection, 4,4'-dihydroxyazobenzene, glycidyl methacrylate, and catalyst tetrabutylammonium bromide are mixed, then the temperature is raised to 78-82°C, and the reaction is carried out for 3.5-4.5 hours. After the reaction is completed, the mixture is cooled to room temperature, tetrahydrofuran (200 times the mass of 4,4'-dihydroxyazobenzene) is added, stirred and dissolved, and deionized water (500 times the mass of 4,4'-dihydroxyazobenzene) and 68-72°C are added and mixed, and the mixture is allowed to stand for stratification to remove the upper liquid to remove the catalyst and small molecular products, and hot water washing, washing, washing, etc. are repeated in sequence. The steps of standing to separate layers and removing the upper layer of liquid are repeated 2 to 4 times, and then dried to obtain an intermediate product a; the intermediate product a, p-chloromethylbenzoic acid, phosphorus oxychloride, anhydrous zinc chloride, and solvent sulfolane are stirred and mixed, and then heated to 70 to 75° C., and kept warm for reaction for 1.8 to 2.2 hours, and then deionized water is added at a rate of 10 mL / min, and stirred for 25 to 30 minutes, and cold water 24 to 26 times the mass of phosphorus oxychloride is poured in, and stirring is continued for 10 to 20 minutes. After standing for 25 to 35 minutes, the mixture is cooled to below 20° C., filtered, washed with water, and dried to obtain an azo acrylic acid monomer.

10. The method for preparing the weather-resistant water-based latex paint according to claim 9, characterized in that: The molar ratio of 4'-dihydroxyazobenzene to glycidyl methacrylate is 1:0.8-1.2; the dosage of the catalyst tetrabutylammonium bromide is 4.5%-5%; the molar ratio of the intermediate product a, p-chloromethylbenzoic acid, phosphorus oxychloride and anhydrous zinc chloride is 0.113-0.115:0.109-0.111:0.18-0.22:0.14-0.16; the mass ratio of the solvent sulfolane, deionized water and phosphorus oxychloride is 0.62-0.64:2.5-3.5:1.

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