An environmentally friendly indoor paint that can filter PM2.5

Abstract

The invention discloses an indoor environmentally friendly paint capable of filtering PM2.5. The indoor environmentally friendly paint capable of filtering PM2.5 is prepared from the following components in parts by weight: 8-20 parts of polyacrylate, 1-4 parts of polyacrylic acid, 1-2 parts of PM2.5 adsorption composite resin, 1-4 parts of lignin-based antioxidant, 2-5 parts of wetting agent, 2-6 parts of defoamer, and 4-8 parts of thickener; wherein the PM2.5 adsorption composite resin is obtained by compounding an adsorption resin obtained by polystyrene microspheres, p-phenylenediamine, and terephthalaldehyde, and the lignin-based antioxidant is obtained by demethylating willow wood by iodocyclohexane. Adding the PM2.5 adsorption composite resin and the lignin-based antioxidant to the environmentally friendly paint can not only effectively filter PM2.5, but also increase the service life of the paint.

Description

Technical Field

[0001] The invention belongs to the technical field of environmentally friendly coatings, and in particular relates to an indoor environmentally friendly coating capable of filtering PM2.5. Background Art

[0002] In recent years, with the acceleration of industrialization and the improvement of urbanization, air pollution has become increasingly serious, and fine particulate matter such as PM2.5 has become one of the main pollutants affecting public health. As the main place for people's daily life and work, the air quality of indoor environment is directly related to people's physical and mental health.

[0003] Patent CN 104479485 B discloses an environmentally friendly coating for reducing PM2.5 in the air and its preparation method. The raw material components thereof are proportioned by weight as follows: 70-80 parts of coating agent; 7-15 parts of photocatalyst material; 1-15 parts of reinforcing agent; 10-20 parts of additive; the raw materials of the additive are proportioned by weight as follows: 0.1-0.5 parts of dispersant; 0.1-0.5 parts of defoaming agent; 10-20 parts of water. The environmentally friendly coating of the invention has a simple production process, does not cause secondary pollution, and can effectively increase the adhesion to the base layer, so that the coating is better bonded to the substrate, but the environmentally friendly coating obtained by this method still has room for improvement in the PM2.5 filtering performance and durability. Summary of the invention

[0004] The purpose of the present invention is to provide an indoor environmentally friendly paint that can filter PM2.5, so as to solve the technical problems of poor filtering performance and durability of environmentally friendly paints on PM2.5 in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The invention provides an indoor environmentally friendly paint capable of filtering PM2.5, which is prepared from the following components in parts by weight: 8-20 parts of polyacrylate, 1-4 parts of polyacrylic acid, 1-2 parts of PM2.5 adsorbing composite resin, 1-4 parts of lignin-based antioxidant, 2-5 parts of wetting agent, 2-6 parts of defoaming agent, and 4-8 parts of thickener; wherein the PM2.5 adsorbing composite resin is obtained by compounding an adsorption resin obtained through polystyrene microspheres, p-phenylenediamine, and terephthalaldehyde, and the lignin-based antioxidant is obtained by demethylating willow lignin through iodocyclohexane.

[0007] Preferably, the method for preparing the PM2.5 adsorbing composite resin comprises the following steps:

[0008] Q1: Add polyethylene glycol octylphenyl ether and polyvinyl pyrrolidone into a beaker containing methanol, stir to dissolve, then add azobisisobutyl cyanide and styrene, and mechanically stir under nitrogen protection, heat up, and continue stirring. After stirring, wash and vacuum dry to obtain polystyrene microspheres;

[0009] Q2: The obtained polystyrene microspheres are dispersed in a mixed solution of polyvinyl alcohol and sodium dodecyl sulfate, and the mixture is stirred evenly to obtain solution A. Glycidyl methacrylate, ethylene glycol dimethacrylate and azobisisobutyl cyanide are dissolved in an acetone solution to obtain solution B. Solution A and solution B are mixed, emulsified in an ultrasonic crusher, and after swelling, transferred to a constant temperature system to continue the reaction. After the reaction is completed, the polymer is washed and vacuum dried to obtain an adsorption resin;

[0010] Q3: Disperse the adsorption resin, p-phenylenediamine and terephthalaldehyde in dioxane, then add acetic acid aqueous solution, place the mixed solution in an oil bath, and mechanically stir it under nitrogen protection. After stirring, centrifuge, wash, and vacuum dry to obtain a composite resin for adsorbing PM2.5.

[0011] In the above process, the adsorption resin is first prepared by the seed swelling method, which is represented by R in the reaction process, and then the PM2.5 adsorption composite resin is synthesized by Schiff base condensation reaction and one-pot method, wherein the reaction process of Q3 is as follows:

[0012]

[0013] Preferably, in Q1, the molecular mass of polyvinyl pyrrolidone is 58kDa, the mechanical stirring time is 30-50min, the heating temperature is 70-80°C, the stirring time is continued for 20-24h, and the washing is carried out with methanol for 3-5 times; in Q2, the volume ratio of polyvinyl alcohol to sodium dodecyl sulfate is 4:1, the swelling temperature is 30-35°C, the swelling time is 10-12h, the temperature of the constant temperature system is 70-80°C, the reaction time is continued for 20-24h, the washing is carried out with tetrahydrofuran and methanol for 3-5 times respectively, the vacuum drying temperature is 60-70°C, and the vacuum drying time is 24-28h.

[0014] Preferably, in Q3, the dosage ratio of adsorption resin, p-phenylenediamine, terephthalaldehyde, dioxane and acetic acid aqueous solution is (290-310) mg: (35-45) mg: (45-50) mg: 20 mL: (0.5-0.8) mL, the concentration of acetic acid aqueous solution is 3 mol / L, the temperature of the oil bath is 80-100°C, the mechanical stirring time is 20-24 h, and the mixture is washed with tetrahydrofuran and methanol for 3-5 times respectively. The vacuum drying temperature is 120-140°C, and the vacuum drying time is 10-12 h.

[0015] Preferably, the method for preparing the lignin-based antioxidant comprises the following steps:

[0016] S1: crushing, sieving and drying the willow wood chips raw material into a high-pressure reactor, adding a mixed solution of tetrahydrofurfuryl alcohol and water, sealing and replacing with nitrogen, then filling with nitrogen, stirring, heating and reacting, after the reaction is completed, placing the high-pressure reactor in an ice-water bath to cool to room temperature, filtering and separating the reaction liquid, washing the filter cake with a mixed solution of tetrahydrofurfuryl alcohol and water, collecting the filtrate and the filter cake washing liquid, combining the two, adding to deionized water, continuing to stir, centrifuging, washing with water, collecting the precipitate, and vacuum drying to obtain willow wood lignin;

[0017] S2: Add willow lignin into a pressure-resistant reaction tube, add N,N-dimethylformamide and stir thoroughly to dissolve, then add iodocyclohexane, heat the pressure-resistant reaction tube, continue stirring and reflux, extract and wash with n-hexane after the reaction, collect the lower layer solution, slowly add the lower layer solution dropwise into hydrochloric acid under vigorous stirring, continue stirring, centrifuge, wash, and vacuum dry to obtain a lignin-based antioxidant.

[0018] In the above process, willow lignin is first obtained from willow wood chips by alcoholysis, and then the willow lignin is demethylated using iodocyclohexane as a demethylation reagent and N,N-dimethylformamide as a solvent to prepare a lignin-based antioxidant.

[0019] Preferably, in S1, the particle size after crushing and sieving is 80-100 mesh, the drying temperature is 100-110°C, the drying time is 4-6h, the number of replacements is 5-7 times, the stirring speed is 1000-1300rpm, the heating temperature is 190-200°C, the reaction time is 3-4h, the continued stirring time is 2-3h, the vacuum drying temperature is 40-50°C, and the vacuum drying time is 22-24h.

[0020] Preferably, in S2, the dosage ratio of willow lignin, N,N-dimethylformamide, iodocyclohexane, n-hexane and hydrochloric acid is (0.3-0.7) g: (11-13) mL: (3-4) mL: (20-30) mL: (120-130) mL, the heating temperature is 120-140°C, the reflux time is 10-12h, the concentration of hydrochloric acid is 2 mol / L, the stirring time is continued for 3-5h, and the vacuum drying temperature is 40-50°C.

[0021] Preferably, the method for preparing an indoor environmentally friendly coating capable of filtering PM2.5 comprises the following steps:

[0022] Step (1): stirring polyacrylate and polyacrylic acid in a stirrer at a uniform speed to obtain a mixture 1;

[0023] Step (2): adding the PM2.5 adsorbing composite resin and the lignin-based antioxidant to the thickener, mixing and stirring to obtain a mixture 2;

[0024] Step (3): Mix and stir the wetting agent and the defoaming agent, add the mixture 1 and stir, then add the mixture 2, adjust the speed and stir to mix them evenly to obtain an indoor environmentally friendly paint that can filter PM2.5.

[0025] Preferably, in step (1), the uniform stirring speed is 20-30 rpm; in step (2), the mixing and stirring speed is 300-400 rpm, and the stirring time is 5-10 min; in step (3), the mixing and stirring speed is 500-600 rpm, the adjustment speed is 1600-2000 rpm, and the stirring time is 30-40 min.

[0026] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0027] 1. In the present invention, the adsorption resin is first synthesized by seed swelling polymerization method, and then a microporous organic polymer with a large specific surface area is modified on its surface by a one-pot method to obtain a PM2.5 adsorbing composite resin, and then the willow lignin is obtained from willow wood chips by alcoholysis method, and then demethylation is performed to prepare a lignin-based antioxidant. Adding the PM2.5 adsorbing composite resin to environmentally friendly coatings can effectively filter PM2.5 and reduce the harm of PM2.5. Adding the lignin-based antioxidant to the environmentally friendly coating can effectively improve the durability of the environmentally friendly coating and increase the service life of the environmentally friendly coating.

[0028] 2. The present invention uses polyethylene glycol octylphenyl ether, polyvinyl pyrrolidone, azobisisobutyl cyanide and styrene as raw materials to prepare polystyrene microspheres, and then disperses the polystyrene microspheres in a mixed solution of polyvinyl alcohol and sodium dodecyl sulfate, and simultaneously adds a mixed solution of glycidyl methacrylate, ethylene glycol dimethacrylate, azobisisobutyl cyanide and acetone, and obtains an adsorption resin after emulsification and swelling, and then modifies the microporous organic polymer on the resin surface through Schiff base reaction and one-pot method, thereby obtaining a PM2.5 adsorption composite resin with excellent adsorption capacity, and physical interactions such as van der Waals force formed between PM2.5 particles and the resin surface cause PM2.5 to be adsorbed on the resin surface, and at the same time, the synthesized PM2.5 adsorption composite resin has polar group hydroxyl groups, which can form hydrogen bonds with polar components in PM2.5, thereby enhancing the resin's adsorption capacity for PM2.5, and the presence of hydroxyl groups can also synergize with other functional groups to further improve the adsorption performance of the composite resin, and adding it to environmentally friendly coatings can effectively increase the performance of the coating in filtering PM2.5.

[0029] 3. In the present invention, lignin is extracted from willow, and then a lignin-based antioxidant is obtained by demethylation. The obtained lignin-based antioxidant has excellent antioxidant properties. Adding it to a coating can effectively improve the durability of the coating. This is because the lignin-based antioxidant contains multiple aromatic ring structures and groups such as hydroxyl groups, which can react with free radicals of key intermediates that trigger oxidation reactions, capture free radicals and inhibit the continued free radical chain reaction, prevent the oxidation reaction in the coating, and the hydroxyl groups contained can be reduced by oxides to inhibit further generation of oxides; and the functional groups in the lignin-based antioxidant can form complexes with metal ions to prevent metal ions from participating in oxidation reactions and promote oxidation; the light absorption properties of the lignin-based antioxidant can absorb harmful light such as ultraviolet light and visible light, reduce light-induced oxidation reactions, thereby protecting the coating surface from damage by light and extending the service life of the coating. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are described clearly and completely below. 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 creative work are within the scope of protection of the present invention.

[0031] Example 1

[0032] This embodiment discloses a method for preparing a lignin-based antioxidant, comprising the following steps:

[0033] S1: The willow wood chips raw material was crushed through a 100 mesh sieve, dried at 110°C for 4 hours, and then placed in a high-pressure reactor, and a mixed solution of tetrahydrofurfuryl alcohol and water was added. After sealing, the mixture was replaced with nitrogen for 6 times, and then filled with nitrogen. The mixture was stirred at 1300 rpm and heated at 200°C for 3 hours. After the reaction was completed, the high-pressure reactor was placed in an ice-water bath and cooled to room temperature. The reaction liquid was separated by suction filtration, and the filter cake was washed with a mixed solution of tetrahydrofurfuryl alcohol and water. The filtrate and the filter cake washing liquid were collected, and the two were combined and added to deionized water. The mixture was stirred for 3 hours, centrifuged, washed with water, and the precipitate was collected. The mixture was vacuum dried at 50°C for 24 hours to obtain willow wood lignin;

[0034] S2: Add 0.5g of willow lignin into a pressure-resistant reaction tube, add 12mL of N,N-dimethylformamide and stir thoroughly to dissolve, then add 3.5mL of iodocyclohexane, heat the pressure-resistant reaction tube at 140°C, continue stirring and reflux for 12h, extract and wash with 25mL of n-hexane after the reaction, collect the lower layer solution, slowly add the lower layer solution dropwise into 125mL of 2mol / L hydrochloric acid under vigorous stirring, continue stirring for 4h, centrifuge, wash, and dry in vacuo at 45°C to obtain a lignin-based antioxidant.

[0035] Example 2

[0036] This embodiment discloses a method for preparing a composite resin for adsorbing PM2.5, comprising the following steps:

[0037] Q1: Add polyethylene glycol octylphenyl ether and polyvinyl pyrrolidone with a molecular weight of 58kDa into a beaker containing methanol, stir to dissolve, add azobisisobutyl cyanide and styrene, and mechanically stir for 50 minutes under nitrogen protection, heat to 80°C, and continue stirring for 24 hours. After stirring, wash with methanol 5 times and vacuum dry to obtain polystyrene microspheres;

[0038] Q2: The obtained polystyrene microspheres were dispersed in a mixed solution of polyvinyl alcohol and sodium dodecyl sulfate (the volume ratio of polyvinyl alcohol to sodium dodecyl sulfate was 4:1), and the solution A was obtained after being stirred evenly. Glycidyl methacrylate, ethylene glycol dimethacrylate and azobisisobutyl cyanide were dissolved in an acetone solution to obtain a solution B. After mixing the solution A and the solution B, the mixture was emulsified in an ultrasonic crusher, swollen at 35°C for 12 hours, and then transferred to a constant temperature system at 70°C to continue the reaction for 24 hours. After the reaction was completed, the polymer was washed three times with tetrahydrofuran and methanol respectively, and vacuum dried at 70°C for 24 hours to obtain an adsorption resin.

[0039] Q3: Disperse 300 mg of adsorption resin, 40 mg of p-phenylenediamine, and 47 mg of terephthalaldehyde in 20 mL of dioxane, then add 0.65 mL of 3 mol / L acetic acid aqueous solution, place the mixture in an 80°C oil bath, and mechanically stir for 24 hours under nitrogen protection. After stirring, centrifuge, wash with tetrahydrofuran and methanol for 4 times respectively, and vacuum dry at 130°C for 12 hours to obtain a composite resin for adsorbing PM2.5.

[0040] The present embodiment discloses an indoor environmentally friendly paint capable of filtering PM2.5, which is prepared from the following ingredients in parts by weight: 14 parts of polyacrylate, 2.5 parts of polyacrylic acid, 1 part of PM2.5 adsorbing composite resin, 1 part of lignin-based antioxidant, 3 parts of wetting agent, 4 parts of defoaming agent, and 6 parts of thickener.

[0041] This embodiment discloses a method for preparing an indoor environmentally friendly coating capable of filtering PM2.5, comprising the following steps:

[0042] Step (1): stirring polyacrylate and polyacrylic acid in a stirrer at a speed of 30 rpm to obtain a mixture 1;

[0043] Step (2): adding the PM2.5 adsorbing composite resin and the lignin-based antioxidant to the thickener, and mixing and stirring at 400 rpm for 10 min to obtain a mixture 2;

[0044] Step (3): Mix and stir the wetting agent and the defoaming agent, add the mixture 1 and stir at 500 rpm, then add the mixture 2, adjust the speed to 2000 rpm and stir for 40 minutes to mix them evenly to obtain an indoor environmentally friendly paint that can filter PM2.5.

[0045] Example 3

[0046] This embodiment discloses a method for preparing a composite resin for adsorbing PM2.5, comprising the following steps:

[0047] Q1: Add polyethylene glycol octylphenyl ether and polyvinyl pyrrolidone with a molecular weight of 58kDa into a beaker containing methanol, stir to dissolve, add azobisisobutyl cyanide and styrene, and mechanically stir for 50 minutes under nitrogen protection, heat to 80°C, and continue stirring for 24 hours. After stirring, wash with methanol 5 times and vacuum dry to obtain polystyrene microspheres;

[0048] Q2: The obtained polystyrene microspheres were dispersed in a mixed solution of polyvinyl alcohol and sodium dodecyl sulfate (the volume ratio of polyvinyl alcohol to sodium dodecyl sulfate was 4:1), and the solution A was obtained after being stirred evenly. Glycidyl methacrylate, ethylene glycol dimethacrylate and azobisisobutyl cyanide were dissolved in an acetone solution to obtain a solution B. After mixing the solution A and the solution B, the mixture was emulsified in an ultrasonic crusher, swollen at 35°C for 12 hours, and then transferred to a constant temperature system at 70°C to continue the reaction for 24 hours. After the reaction was completed, the polymer was washed three times with tetrahydrofuran and methanol respectively, and vacuum dried at 70°C for 24 hours to obtain an adsorption resin.

[0049] Q3: Disperse 292 mg of adsorption resin, 38 mg of p-phenylenediamine, and 45 mg of terephthalaldehyde in 20 mL of dioxane, then add 0.5 mL of 3 mol / L acetic acid aqueous solution, place the mixture in an 80°C oil bath, and mechanically stir for 24 hours under nitrogen protection. After stirring, centrifuge, wash with tetrahydrofuran and methanol for 4 times respectively, and vacuum dry at 130°C for 12 hours to obtain a composite resin for adsorbing PM2.5.

[0050] The present embodiment discloses an indoor environmentally friendly paint capable of filtering PM2.5, which is prepared from the following ingredients in parts by weight: 10 parts of polyacrylate, 1 part of polyacrylic acid, 2 parts of PM2.5 adsorbing composite resin, 1 part of lignin-based antioxidant, 3 parts of wetting agent, 2 parts of defoaming agent, and 5 parts of thickener.

[0051] This embodiment discloses a method for preparing an indoor environmentally friendly coating capable of filtering PM2.5, comprising the following steps:

[0052] Step (1): stirring polyacrylate and polyacrylic acid in a stirrer at a speed of 30 rpm to obtain a mixture 1;

[0053] Step (2): adding the PM2.5 adsorbing composite resin and the lignin-based antioxidant to the thickener, and mixing and stirring at 400 rpm for 10 min to obtain a mixture 2;

[0054] Step (3): Mix and stir the wetting agent and the defoaming agent, add the mixture 1 and stir at 500 rpm, then add the mixture 2, adjust the speed to 2000 rpm and stir for 40 minutes to mix them evenly to obtain an indoor environmentally friendly paint that can filter PM2.5.

[0055] Example 4

[0056] This embodiment discloses a method for preparing a composite resin for adsorbing PM2.5, comprising the following steps:

[0057] Q1: Add polyethylene glycol octylphenyl ether and polyvinyl pyrrolidone with a molecular weight of 58kDa into a beaker containing methanol, stir to dissolve, add azobisisobutyl cyanide and styrene, and mechanically stir for 50 minutes under nitrogen protection, heat to 80°C, and continue stirring for 24 hours. After stirring, wash with methanol 5 times and vacuum dry to obtain polystyrene microspheres;

[0058] Q2: The obtained polystyrene microspheres were dispersed in a mixed solution of polyvinyl alcohol and sodium dodecyl sulfate (the volume ratio of polyvinyl alcohol to sodium dodecyl sulfate was 4:1), and the solution A was obtained after being stirred evenly. Glycidyl methacrylate, ethylene glycol dimethacrylate and azobisisobutyl cyanide were dissolved in an acetone solution to obtain a solution B. After mixing the solution A and the solution B, the mixture was emulsified in an ultrasonic crusher, swollen at 35°C for 12 hours, and then transferred to a constant temperature system at 70°C to continue the reaction for 24 hours. After the reaction was completed, the polymer was washed three times with tetrahydrofuran and methanol respectively, and vacuum dried at 70°C for 24 hours to obtain an adsorption resin.

[0059] Q3: Disperse 308 mg of adsorption resin, 42 mg of p-phenylenediamine, and 50 mg of terephthalaldehyde in 20 mL of dioxane, then add 0.8 mL of 3 mol / L acetic acid aqueous solution, place the mixture in an 80°C oil bath, and mechanically stir for 24 hours under nitrogen protection. After stirring, centrifuge, wash with tetrahydrofuran and methanol for 4 times respectively, and vacuum dry at 130°C for 12 hours to obtain a composite resin for adsorbing PM2.5.

[0060] The present embodiment discloses an indoor environmentally friendly paint capable of filtering PM2.5, which is prepared from the following ingredients in parts by weight: 18 parts of polyacrylate, 3 parts of polyacrylic acid, 2 parts of PM2.5 adsorbing composite resin, 2 parts of lignin-based antioxidant, 4 parts of wetting agent, 5 parts of defoaming agent, and 6 parts of thickener.

[0061] This embodiment discloses a method for preparing an indoor environmentally friendly coating capable of filtering PM2.5, comprising the following steps:

[0062] Step (1): stirring polyacrylate and polyacrylic acid in a stirrer at a speed of 30 rpm to obtain a mixture 1;

[0063] Step (2): adding the PM2.5 adsorbing composite resin and the lignin-based antioxidant to the thickener, and mixing and stirring at 400 rpm for 10 min to obtain a mixture 2;

[0064] Step (3): Mix and stir the wetting agent and the defoaming agent, add the mixture 1 and stir at 500 rpm, then add the mixture 2, adjust the speed to 2000 rpm and stir for 40 minutes to mix them evenly to obtain an indoor environmentally friendly paint that can filter PM2.5.

[0065] Example 5

[0066] This embodiment discloses a method for preparing a composite resin for adsorbing PM2.5, comprising the following steps:

[0067] Q1: Add polyethylene glycol octylphenyl ether and polyvinyl pyrrolidone with a molecular weight of 58kDa into a beaker containing methanol, stir to dissolve, add azobisisobutyl cyanide and styrene, and mechanically stir for 50 minutes under nitrogen protection, heat to 80°C, and continue stirring for 24 hours. After stirring, wash with methanol 5 times and vacuum dry to obtain polystyrene microspheres;

[0068] Q2: The obtained polystyrene microspheres were dispersed in a mixed solution of polyvinyl alcohol and sodium dodecyl sulfate (the volume ratio of polyvinyl alcohol to sodium dodecyl sulfate was 4:1), and the solution A was obtained after being stirred evenly. Glycidyl methacrylate, ethylene glycol dimethacrylate and azobisisobutyl cyanide were dissolved in an acetone solution to obtain a solution B. After mixing the solution A and the solution B, the mixture was emulsified in an ultrasonic crusher, swollen at 35°C for 12 hours, and then transferred to a constant temperature system at 70°C to continue the reaction for 24 hours. After the reaction was completed, the polymer was washed three times with tetrahydrofuran and methanol respectively, and vacuum dried at 70°C for 24 hours to obtain an adsorption resin.

[0069] Q3: Disperse 295 mg of adsorption resin, 35 mg of p-phenylenediamine, and 48 mg of terephthalaldehyde in 20 mL of dioxane, then add 0.7 mL of 3 mol / L acetic acid aqueous solution, place the mixture in an 80°C oil bath, and mechanically stir for 24 hours under nitrogen protection. After stirring, centrifuge, wash with tetrahydrofuran and methanol for 4 times respectively, and vacuum dry at 130°C for 12 hours to obtain a composite resin for adsorbing PM2.5.

[0070] The present embodiment discloses an indoor environmentally friendly paint capable of filtering PM2.5, which is prepared from the following ingredients in parts by weight: 12 parts of polyacrylate, 4 parts of polyacrylic acid, 1 part of PM2.5 adsorbing composite resin, 3 parts of lignin-based antioxidant, 2 parts of wetting agent, 6 parts of defoaming agent, and 7 parts of thickener.

[0071] This embodiment discloses a method for preparing an indoor environmentally friendly coating capable of filtering PM2.5, comprising the following steps:

[0072] Step (1): stirring polyacrylate and polyacrylic acid in a stirrer at a speed of 30 rpm to obtain a mixture 1;

[0073] Step (2): adding the PM2.5 adsorbing composite resin and the lignin-based antioxidant to the thickener, and mixing and stirring at 400 rpm for 10 min to obtain a mixture 2;

[0074] Step (3): Mix and stir the wetting agent and the defoaming agent, add the mixture 1 and stir at 500 rpm, then add the mixture 2, adjust the speed to 2000 rpm and stir for 40 minutes to mix them evenly to obtain an indoor environmentally friendly paint that can filter PM2.5.

[0075] Example 6

[0076] This embodiment discloses a method for preparing a composite resin for adsorbing PM2.5, comprising the following steps:

[0077] Q1: Add polyethylene glycol octylphenyl ether and polyvinyl pyrrolidone with a molecular weight of 58kDa into a beaker containing methanol, stir to dissolve, add azobisisobutyl cyanide and styrene, and mechanically stir for 50 minutes under nitrogen protection, heat to 80°C, and continue stirring for 24 hours. After stirring, wash with methanol 5 times and vacuum dry to obtain polystyrene microspheres;

[0078] Q2: The obtained polystyrene microspheres were dispersed in a mixed solution of polyvinyl alcohol and sodium dodecyl sulfate (the volume ratio of polyvinyl alcohol to sodium dodecyl sulfate was 4:1), and the solution A was obtained after being stirred evenly. Glycidyl methacrylate, ethylene glycol dimethacrylate and azobisisobutyl cyanide were dissolved in an acetone solution to obtain a solution B. After mixing the solution A and the solution B, the mixture was emulsified in an ultrasonic crusher, swollen at 35°C for 12 hours, and then transferred to a constant temperature system at 70°C to continue the reaction for 24 hours. After the reaction was completed, the polymer was washed three times with tetrahydrofuran and methanol respectively, and vacuum dried at 70°C for 24 hours to obtain an adsorption resin.

[0079] Q3: Disperse 303 mg of adsorption resin, 45 mg of p-phenylenediamine, and 46 mg of terephthalaldehyde in 20 mL of dioxane, then add 0.6 mL of 3 mol / L acetic acid aqueous solution, place the mixture in an 80°C oil bath, and mechanically stir for 24 hours under nitrogen protection. After stirring, centrifuge, wash with tetrahydrofuran and methanol for 4 times respectively, and vacuum dry at 130°C for 12 hours to obtain a composite resin for adsorbing PM2.5.

[0080] The present embodiment discloses an indoor environmentally friendly paint capable of filtering PM2.5, which is prepared from the following ingredients in parts by weight: 16 parts of polyacrylate, 2 parts of polyacrylic acid, 1 part of PM2.5 adsorbing composite resin, 4 parts of lignin-based antioxidant, 5 parts of wetting agent, 3 parts of defoaming agent, and 8 parts of thickener.

[0081] This embodiment discloses a method for preparing an indoor environmentally friendly coating capable of filtering PM2.5, comprising the following steps:

[0082] Step (1): stirring polyacrylate and polyacrylic acid in a stirrer at a speed of 30 rpm to obtain a mixture 1;

[0083] Step (2): adding the PM2.5 adsorbing composite resin and the lignin-based antioxidant to the thickener, and mixing and stirring at 400 rpm for 10 min to obtain a mixture 2;

[0084] Step (3): Mix and stir the wetting agent and the defoaming agent, add the mixture 1 and stir at 500 rpm, then add the mixture 2, adjust the speed to 2000 rpm and stir for 40 minutes to mix them evenly to obtain an indoor environmentally friendly paint that can filter PM2.5.

[0085] Comparative Example 1

[0086] Compared with Example 2, in Comparative Example 1, during the preparation of the indoor environmentally friendly paint capable of filtering PM2.5, no composite resin for adsorbing PM2.5 was added, and other conditions remained unchanged.

[0087] Comparative Example 2

[0088] Compared with Example 2, in Comparative Example 2, during the preparation of the indoor environmentally friendly paint capable of filtering PM2.5, no lignin-based antioxidant is added, and other conditions remain unchanged.

[0089] Comparative Example 3

[0090] Comparative Example 3 Compared with Example 2, in the process of preparing the indoor environmentally friendly paint capable of filtering PM2.5, willow lignin is used instead of the lignin-based antioxidant in Comparative Example 2, and other conditions remain unchanged.

[0091] Comparative Example 4

[0092] Comparative Example 4 Compared with Example 2, in the process of preparing the indoor environmentally friendly paint capable of filtering PM2.5, the added PM2.5 adsorbing composite resin does not contain p-phenylenediamine and p-terephthalaldehyde, and other conditions remain unchanged.

[0093] Experimental example

[0094] The performance of the PM2.5-filtering indoor environmentally friendly coatings prepared in Examples 2-6 and Comparative Examples 1-4 was tested.

[0095] 1. PM2.5 filtration performance test

[0096] The obtained samples were placed in a PM2.5 environment, where the PM2.5 generator used a sealed container with built-in carbon powder. The carbon powder burned under insufficient oxygen supply conditions to produce solid particles. The initial value of PM2.5 was stabilized at (95-105) μg / m 3 Range, using PM2.5 air detector to test the initial concentration of PM2.5 and the concentration after filtration, according to the reduction rate = (1-N2 / N1) × 100%, where N1 represents the concentration of PM2.5 in the air before filtration, and N2 represents the concentration of PM2.5 in the air after 24h filtration. The test results are shown in Table 1:

[0097] Table 1

[0098]

[0099]

[0100] From the test results in Table 1, it can be seen that the PM2.5 filtering indoor environmentally friendly paint prepared by Examples 2-6 of the present invention has excellent ability to filter PM2.5. From the comparison between Comparative Example 1 and Examples 2-6, it can be seen that adding a composite resin that absorbs PM2.5 can effectively improve the PM2.5 filtering ability of the paint; from the comparison between Comparative Example 4 and Examples 2-6, it can be seen that adding p-phenylenediamine and terephthalaldehyde can improve the PM2.5 filtering ability of the paint.

[0101] 2. Persistence Test

[0102] The adhesion of the samples was tested according to ISO 4624, and the blistering and color difference of the samples were evaluated according to GB / T 1766-2008. The test results are shown in Table 2:

[0103] Table 1

[0104]

[0105] From the test results in Table 2, it can be seen that the PM2.5-filtering indoor environmentally friendly paint prepared in Examples 2-6 of the present invention has excellent durability. From the comparison between Comparative Example 1 and Examples 2-6, it can be seen that the addition of a composite resin that absorbs PM2.5 can effectively improve the durability of the paint; from the comparison between Comparative Example 2 and Examples 2-6, it can be seen that the addition of a lignin-based antioxidant can effectively improve the durability of the paint; from the comparison between Comparative Example 3 and Examples 2-6, it can be seen that replacing the lignin-based antioxidant with willow wood will reduce the durability of the paint; from the comparison between Comparative Example 4 and Examples 2-6, it can be seen that the addition of p-phenylenediamine and terephthalaldehyde can improve the durability of the paint.

[0106] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0107] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. An indoor environmentally friendly paint capable of filtering PM2.5, characterized in that: The invention is prepared from the following ingredients in parts by weight: 8-20 parts of polyacrylate, 1-4 parts of polyacrylic acid, 1-2 parts of PM2.5 adsorption composite resin, 1-4 parts of lignin-based antioxidant, 2-5 parts of wetting agent, 2-6 parts of defoaming agent, and 4-8 parts of thickener; wherein the PM2.5 adsorption composite resin is obtained by compounding an adsorption resin obtained by polystyrene microspheres, p-phenylenediamine, and terephthalaldehyde, and the lignin-based antioxidant is obtained by demethylating willow wood lignin by iodocyclohexane. The preparation method of the PM2.5 adsorbing composite resin comprises the following steps: Q1: Add polyethylene glycol octylphenyl ether and polyvinyl pyrrolidone into a beaker containing methanol, stir to dissolve, then add azobisisobutyl cyanide and styrene, and mechanically stir under nitrogen protection, heat up, and continue stirring. After stirring, wash and vacuum dry to obtain polystyrene microspheres; Q2: The obtained polystyrene microspheres are dispersed in a mixed solution of polyvinyl alcohol and sodium dodecyl sulfate, and the mixture is stirred evenly to obtain solution A. Glycidyl methacrylate, ethylene glycol dimethacrylate and azobisisobutyl cyanide are dissolved in an acetone solution to obtain solution B. Solution A and solution B are mixed, emulsified in an ultrasonic crusher, and after swelling, transferred to a constant temperature system to continue the reaction. After the reaction is completed, the polymer is washed and vacuum dried to obtain an adsorption resin; Q3: Disperse the adsorption resin, p-phenylenediamine and terephthalaldehyde in dioxane, then add acetic acid aqueous solution, place the mixed solution in an oil bath, and mechanically stir under nitrogen protection. After stirring, centrifuge, wash, and vacuum dry to obtain a composite resin for adsorbing PM2.5; The preparation method of the lignin-based antioxidant comprises the following steps: S1: crushing, sieving and drying the willow wood chips raw material into a high-pressure reactor, adding a mixed solution of tetrahydrofurfuryl alcohol and water, sealing and replacing with nitrogen, then filling with nitrogen, stirring, heating and reacting, after the reaction is completed, placing the high-pressure reactor in an ice-water bath to cool to room temperature, filtering and separating the reaction liquid, washing the filter cake with a mixed solution of tetrahydrofurfuryl alcohol and water, collecting the filtrate and the filter cake washing liquid, combining the two, adding to deionized water, continuing to stir, centrifuging, washing with water, collecting the precipitate, and vacuum drying to obtain willow wood lignin; S2: Add willow lignin into a pressure-resistant reaction tube, add N,N-dimethylformamide and stir thoroughly to dissolve, then add iodocyclohexane, heat the pressure-resistant reaction tube, continue stirring and reflux, extract and wash with n-hexane after the reaction, collect the lower layer solution, slowly add the lower layer solution dropwise into hydrochloric acid under vigorous stirring, continue stirring, centrifuge, wash, and vacuum dry to obtain a lignin-based antioxidant.

2. The indoor environmentally friendly paint capable of filtering PM2.5 according to claim 1, characterized in that: In the Q1, the molecular weight of polyvinyl pyrrolidone is 58kDa, the mechanical stirring time is 30-50min, the heating temperature is 70-80℃, the stirring time is continued for 20-24h, and the washing is carried out with methanol for 3-5 times; in the Q2, the volume ratio of polyvinyl alcohol to sodium dodecyl sulfate is 4:1, the swelling temperature is 30-35℃, the swelling time is 10-12h, the temperature of the constant temperature system is 70-80℃, the reaction time is continued for 20-24h, the washing is carried out with tetrahydrofuran and methanol for 3-5 times respectively, the vacuum drying temperature is 60-70℃, and the vacuum drying time is 24-28h.

3. The indoor environmentally friendly paint capable of filtering PM2.5 according to claim 1, characterized in that: In the Q3, the dosage ratio of the adsorption resin, p-phenylenediamine, terephthalaldehyde, dioxane, and acetic acid aqueous solution is (290-310) mg: (35-45) mg: (45-50) mg: 20 mL: (0.5-0.8) mL, the concentration of the acetic acid aqueous solution is 3 mol / L, the temperature of the oil bath is 80-100° C., the mechanical stirring time is 20-24 h, and the mixture is washed with tetrahydrofuran and methanol for 3-5 times respectively. The vacuum drying temperature is 120-140° C., and the vacuum drying time is 10-12 h.

4. The indoor environmentally friendly paint capable of filtering PM2.5 according to claim 1, characterized in that: In S1, the particle size after crushing and sieving is 80-100 mesh, the drying temperature is 100-110°C, the drying time is 4-6h, the replacement times are 5-7 times, the stirring speed is 1000-1300rpm, the heating temperature is 190-200°C, the reaction time is 3-4h, the continued stirring time is 2-3h, the vacuum drying temperature is 40-50°C, and the vacuum drying time is 22-24h.

5. The indoor environmentally friendly paint capable of filtering PM2.5 according to claim 1, characterized in that: In S2, the dosage ratio of willow lignin, N,N-dimethylformamide, iodocyclohexane, n-hexane and hydrochloric acid is (0.3-0.7) g: (11-13) mL: (3-4) mL: (20-30) mL: (120-130) mL, the heating temperature is 120-140°C, the reflux time is 10-12h, the concentration of hydrochloric acid is 2 mol / L, the stirring time is continued for 3-5h, and the vacuum drying temperature is 40-50°C.

6. A method for preparing an indoor environmentally friendly paint capable of filtering PM2.5 according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step (1): stirring polyacrylate and polyacrylic acid in a stirrer at a uniform speed to obtain a mixture 1; Step (2): adding the PM2.5 adsorbing composite resin and the lignin-based antioxidant to the thickener, mixing and stirring to obtain a mixture 2; Step (3): Mix and stir the wetting agent and the defoaming agent, add the mixture 1 and stir, then add the mixture 2, adjust the speed and stir to mix them evenly to obtain an indoor environmentally friendly paint that can filter PM2.

5.

7. The method for preparing the PM2.5-filtering indoor environmentally friendly paint according to claim 6, characterized in that: In the step (1), the uniform stirring speed is 20-30 rpm; in the step (2), the mixing and stirring speed is 300-400 rpm, and the stirring time is 5-10 min; in the step (3), the mixing and stirring speed is 500-600 rpm, the adjusting speed is 1600-2000 rpm, and the stirring time is 30-40 min.

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