Bamboo charcoal antibacterial and odor-removing latex paint and preparation method thereof

Abstract

The present application relates to the technical field of latex paint, and particularly relates to a bamboo charcoal antibacterial and odor-removing latex paint and a preparation method thereof, which comprises nanoscale bamboo charcoal powder, modified chitosan, modified organic nanosheet, ethylene oxide / propylene oxide block copolymer and hydrophobic modified polyurethane; the phthalimide bond formed by the modified chitosan and the modified organic nanosheet is hydrolyzed and broken in the back alkali environment, and two modified substances are released to synergistically play a defense function to protect the integrity of the paint film; the ethylene oxide / propylene oxide block copolymer and the hydrophobic modified polyurethane construct a multi-level stable system, which effectively prevents the flocculation and demulsification between the positively charged quaternary ammonium salt functional substance and the negatively charged emulsion particles.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of latex paint, and particularly relates to a bamboo charcoal antibacterial and odor-removing latex paint and a preparation method thereof. BACKGROUND

[0002] With the continuous improvement of consumer requirements for indoor environmental health and living quality, interior wall latex paint with additional functions such as antibacterial and odor-removing is increasingly favored by the market. Among them, the latex paint added with bamboo charcoal powder can effectively adsorb harmful substances such as formaldehyde and benzene in the air and odor molecules by virtue of its unique physical adsorption capacity, and becomes an important development direction of environmentally friendly functional coatings.

[0003] However, in the actual application process, especially in newly built buildings or low-level humid environments, white crystalline or flocculent substances are often precipitated from the wall base, which is called alkali return. Alkali return can damage the integrity of the paint film, causing irreversible damage such as powdering, blistering and peeling. At present, the industry often uses high-efficiency alkali-resistant sealing primer or adds hydrophobic ingredients in the paint film formula to improve the hydrophobicity of the paint film to solve the problem of alkali return. However, the effect of the sealing primer is greatly dependent on the integrity of the construction and the condition of the base; and excessive improvement of the hydrophobicity of the topcoat may affect the air permeability of the paint film and cause problems such as difficulty in recoating. Therefore, it is of great significance to develop a new type of latex paint that can not only retain the antibacterial and odor-removing properties of bamboo charcoal but also actively, intelligently and efficiently deal with the problem of wall alkali return. SUMMARY

[0004] (1) Technical problem to be solved

[0005] The present application aims to provide a bamboo charcoal antibacterial and odor-removing latex paint and a preparation method thereof, which can protect the integrity of the paint film when the wall returns to alkali.

[0006] (2) Technical scheme

[0007] To achieve the above-mentioned purpose, on the one hand, the present application provides a bamboo charcoal antibacterial and odor-removing latex paint, which comprises the following components in parts by weight: 25-40 parts of nano bamboo charcoal powder, 12-18 parts of modified chitosan, 10-15 parts of modified organic nanosheet, 2.0-3.5 parts of ethylene oxide / propylene oxide block copolymer and 3.0-5.0 parts of hydrophobically modified polyurethane.

[0008] Among them, the modified chitosan and the modified organic nanosheet form a phthalimide bond.

[0009] Further, the ethylene oxide / propylene oxide block copolymer comprises Pluronic® PE 10500, and the hydrophobically modified polyurethane comprises Acrysol™ RM-2020 NPR.

[0010] Further, the components further include the following components in the weight parts: 5.0-7.0 parts of polyacrylic acid ammonium salt dispersant, 1.0-1.8 parts of non-ionic wetting agent, 1.5-2.5 parts of mineral oil antifoaming agent, 180-220 parts of rutile titanium dioxide, 100-140 parts of heavy calcium carbonate, 40-70 parts of calcined kaolin, 1.0-2.0 parts of 2-amino-2-methyl-1-propanol; 280-320 parts of acrylate copolymer emulsion; 8.0-12.0 parts of dodecanol ester; 1.0-1.5 parts of isothiazolinone composite preservative; 0.8-1.2 parts of zinc pyrithione; 30-50 parts of 2% hydroxyethyl cellulose aqueous solution; 180-220 parts of deionized water.

[0011] Further, the polyacrylic acid ammonium salt dispersant includes SN-5027; the non-ionic wetting agent includes Dynol 604; the mineral oil antifoaming agent includes DF-877 of Defeng Chemical Industry; the acrylate copolymer emulsion includes Primal™ AC-261; the isothiazolinone composite preservative includes KATHON® LX-150.

[0012] Further, the preparation method of the modified chitosan includes the following steps:

[0013] S11. Dissolve aluminum nitrate nonahydrate in deionized water to obtain solution A; dissolve trimesic acid in anhydrous ethanol to obtain solution B; under vigorous stirring, pour solution B into solution A quickly, transfer to a high-pressure reaction kettle for reaction, naturally cool to room temperature, centrifuge to collect the precipitate, wash with anhydrous ethanol and deionized water alternately, dry in a vacuum oven overnight to obtain a first compound;

[0014] S12. Dissolve chitosan powder in an aqueous acetic acid solution with a mass fraction of 2%, stir until completely dissolved, heat, and under stirring, add an aqueous solution of 2,3-epoxypropyltrimethylammonium chloride dropwise to react, adjust the pH to neutral, pour into excess acetone, filter to collect the precipitate, redissolve in deionized water after washing with an ethanol / water mixed solution, and freeze-dry to obtain a second compound;

[0015] S13. Dissolve the second compound in deionized water, add the first compound, ultrasonic, then add N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, stir at room temperature, add ethylenediamine, react at room temperature, centrifuge to collect the precipitate, repeatedly centrifuge to wash with deionized water, and freeze-dry to obtain the modified chitosan.

[0016] Further, the volume ratio of ethanol to water in the ethanol / water mixed solution is 4:1.

[0017] Further, the preparation method of the modified organic nanosheet includes the following steps:

[0018] S21. Dissolve 1,3,5-triformylphloroglucinol and 2,5-diethyl-p-phenylenediamine in anhydrous dimethyl sulfoxide respectively, then mix them, add 6 mol / L acetic acid solution to the mixed solution, then add mesitylene, ultrasonic, transfer to a high-pressure reaction kettle for reaction, after cooling, centrifugal collection of precipitate, extract with anhydrous N,N-dimethylformamide and acetone through a Soxhlet extractor, then disperse in deionized water, probe ultrasonic treatment in an ice water bath, centrifugal collection of supernatant and freeze-drying, to obtain a third compound;

[0019] S22. Disperse the third compound in anhydrous N,N-dimethylformamide, add triethylamine, then slowly drop 1,4-butanediol sulfite, warm, stir under nitrogen protection, after reaction, centrifugal collection of precipitate, wash with anhydrous N,N-dimethylformamide and methanol alternately, then disperse in deionized water, dialysis, freeze-drying, to obtain a fourth compound;

[0020] S23. Dissolve 4-carboxyphthalic anhydride in anhydrous N,N-dimethylformamide, add N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, stir at room temperature for activation, then add the fourth compound and triethylamine, warm, stir for reaction, after reaction, centrifugal collection of precipitate, wash with anhydrous N,N-dimethylformamide and acetone alternately, vacuum drying, to obtain modified organic nanosheets.

[0021] Based on the same inventive concept, in a second aspect, the present application also provides a preparation method of the bamboo charcoal antibacterial and odor-removing latex paint, which is applied to the preparation of the bamboo charcoal antibacterial and odor-removing latex paint, and comprises the following steps:

[0022] S31. Preparing slurry: in a dispersion cylinder, add deionized water, slowly add ethylene oxide / propylene oxide block copolymer, polyacrylate ammonium salt dispersant, non-ionic wetting agent and half of the amount of mineral oil defoamer under stirring, continue stirring to ensure that all the additives are completely dissolved and dispersed, slowly add calcined kaolin, stir until there is no obvious dry powder, increase the stirring speed, slowly and uniformly add rutile titanium dioxide, nanoscale bamboo charcoal powder and heavy calcium carbonate, then reduce the stirring speed, slowly add 2-amino-2-methyl-1-propanol, adjust the pH to 8.0-9.0, to obtain the slurry;

[0023] S32. Adjusting paint: keep stirring, slowly add acrylate copolymer emulsion, mix with slurry, slowly and evenly add modified chitosan and modified organic nanosheet, continue stirring to ensure uniform distribution, add dodecanol ester, the remaining half of the mineral oil-based defoamer, isothiazolinone complex preservative, zinc pyrithione in turn, stir for 3-5 min after adding each additive, then add the next one, slowly add 2% hydroxyethyl cellulose solution, then slowly add hydrophobically modified polyurethane, take samples for testing, filter and package after passing the test, to get a bamboo charcoal antibacterial and odor-removing latex paint.

[0024] In the wall alkali return environment, the two modified substances realize the synergistic defense function. The primary amine group on the surface of the modified chitosan forms an alkali-sensitive phthalimide bond with the phthalic anhydride group on the surface of the modified organic nanosheet. The bond exists stably under normal conditions and hydrolyzes and breaks as soon as it encounters an alkali return environment, triggering the defense mechanism. The released modified chitosan immediately plays a multiple ion fixation role: the aluminum-water molecular coordination bond on the surface of the aluminum-based metal organic framework skeleton of the modified chitosan hydrolyzes to generate aluminum-hydroxyl under alkaline conditions, efficiently capturing and fixing the invading calcium ions and potassium ions through ion exchange; at the same time, the quaternary ammonium salt cations grafted on the chitosan chain adsorb anions such as chloride ions through strong electrostatic attraction, realizing the synchronous fixation and charge balance of anions and cations. The simultaneously released modified organic nanosheet plays a sustained neutralization role: its grafted sulfonic acid groups ionize a large number of protons, which react with the invading hydroxide ions to generate water, thereby effectively eliminating alkaline erosion. The entire defense process begins with the alkaline hydrolysis of the phthalimide bond as an intelligent triggering mechanism, and through the spatial release of the two modified substances and the synergistic action of the functional groups, the calcium ions, potassium ions, chloride ions and hydroxide ions released by the wall alkali return are precisely captured and efficiently neutralized, ultimately achieving the purpose of protecting the integrity of the paint film.

[0025] In the bamboo charcoal antibacterial odor-removing latex paint system, the ethylene oxide / propylene oxide block copolymer and the hydrophobic modified polyurethane construct a multi-level stable system, effectively preventing the flocculation and demulsification between the positively charged quaternary ammonium salt functional substances and the negatively charged emulsion particles. The molecular structure of the ethylene oxide / propylene oxide block copolymer simultaneously contains hydrophobic polyoxypropylene segments and hydrophilic polyoxyethylene segments, the hydrophobic segments are firmly anchored on the surfaces of the emulsion particles and functional substance particles by Van der Waals force, and the hydrophilic segments fully stretch into the water phase to form a thick hydration protective layer; when the particles approach each other, the hydration layers overlap to generate strong steric repulsion, effectively preventing the particles with positive and negative charges from flocculating due to electrostatic attraction. At the same time, the long-chain alkane hydrophobic groups at both ends of the hydrophobic modified polyurethane cross-link with the polyoxypropylene hydrophobic segments of the ethylene oxide / propylene oxide block copolymer and the hydrophobic surfaces of the particles, and then weave into a dynamic three-dimensional network structure throughout the system, which greatly improves the viscoelasticity of the system, greatly restricts the free movement ability of the particles from the kinetic level, and thus completely eliminates the risk of demulsification during storage and construction.

[0026] (3) Beneficial effects

[0027] Compared with the prior art, the beneficial effects of the present application are:

[0028] 1. The phthalimide bond formed by the modified chitosan and the modified organic nanosheet in the present application hydrolyzes and breaks down in the back alkali environment, releasing two modified substances to synergistically play a defense function; the modified chitosan plays a multiple ion fixation role, and the simultaneously released modified organic nanosheet plays a sustained neutralization role, achieving precise capture and efficient neutralization of calcium ions, potassium ions, chloride ions and hydroxide ions released by wall back alkali, and ultimately achieving the purpose of protecting the integrity of the paint film.

[0029] 2. The molecular structure of the ethylene oxide / propylene oxide block copolymer in the present application simultaneously contains hydrophobic polyoxypropylene segments and hydrophilic polyoxyethylene segments, the hydrophobic segments are firmly anchored on the surfaces of the emulsion particles and functional substance particles by Van der Waals force, and the hydrophilic segments fully stretch into the water phase to form a thick hydration protective layer; when the particles approach each other, the hydration layers overlap to generate strong steric repulsion, effectively preventing the particles with positive and negative charges from flocculating due to electrostatic attraction.

[0030] 3. The long-chain alkane hydrophobic groups at both ends of the molecules of the hydrophobically modified polyurethane in the present application cross-link with the polyoxypropylene hydrophobic segments of the ethylene oxide / propylene oxide block copolymer and the hydrophobic surfaces of each particle, and then weave into a dynamic three-dimensional network structure throughout the system, which greatly improves the viscoelasticity of the system, greatly restricts the free movement ability of the particles from the kinetic level, and thus completely eliminates the risk of demulsification during storage and construction. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 A preparation flowchart of the bamboo charcoal antibacterial and odor-removing latex paint;

[0032] Figure 2 A comparison chart of the effects of the simulation of the humid environment on the comparative example 1 and the example 1. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with examples. It should be understood that the specific examples described herein are only used to explain the present application and are not used to limit the present application, that is, the described examples are only a part of the examples of the present application, but not all the examples. Based on the examples of the present application, all other examples obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0034] Example 1: The present example discloses a bamboo charcoal antibacterial and odor-removing latex paint, which comprises the following components in parts by weight: 30 parts of nano-sized bamboo charcoal powder, 15 parts of modified chitosan, 12 parts of modified organic nanosheet, 3.0 parts of ethylene oxide / propylene oxide block copolymer, and 4.0 parts of hydrophobically modified polyurethane.

[0035] The modified chitosan and the modified organic nanosheet form a phthalimide bond.

[0036] The ethylene oxide / propylene oxide block copolymer comprises Pluronic® PE 10500, and the hydrophobically modified polyurethane comprises Acrysol™ RM-2020 NPR.

[0037] It further comprises the following components in parts by weight: 6.0 parts of polyacrylic acid ammonium salt dispersant, 1.5 parts of non-ionic wetting agent, 2.0 parts of mineral oil-based defoaming agent, 200 parts of rutile titanium dioxide, 120 parts of heavy calcium carbonate, 50 parts of calcined kaolin, 1.5 parts of 2-amino-2-methyl-1-propanol; 300 parts of acrylate copolymer emulsion; 10.0 parts of lauryl alcohol ester; 1.2 parts of isothiazolinone composite preservative; 1.0 parts of zinc pyrithione; 40 parts of 2% hydroxyethyl cellulose aqueous solution; and 200 parts of deionized water.

[0038] The ammonium polyacrylate dispersant includes SN-5027; the non-ionic wetting agent includes Dynol 604; the mineral oil-based antifoaming agent includes DF-877 of Defeng Chemical Industry; the acrylate copolymer emulsion includes Primal™ AC-261; and the isothiazolinone complex preservative includes KATHON® LX-150.

[0039] The preparation method of the modified chitosan includes the following steps:

[0040] S11. 0.94 g of aluminum nitrate nonahydrate is dissolved in 30 mL of deionized water to obtain solution A; 0.35 g of trimesic acid is dissolved in 30 mL of anhydrous ethanol to obtain solution B; under vigorous stirring, solution B is quickly poured into solution A and transferred to a high-pressure reaction kettle with a polytetrafluoroethylene liner, and reacted at 120°C for 12 h; after natural cooling to room temperature, the precipitate is collected by centrifugation, washed with anhydrous ethanol and deionized water alternately for three times, and dried in a vacuum oven at 60°C overnight to obtain a first compound;

[0041] S12. 1.0 g of chitosan powder is dissolved in 100 mL of 2% by mass acetic acid aqueous solution, stirred until completely dissolved, and heated to 60°C; under stirring, 10 mL of an aqueous solution containing 3.0 g of 2,3-epoxypropyltrimethylammonium chloride is added dropwise, and reacted for 8 h; the pH is adjusted to neutral with sodium hydroxide solution, poured into excess acetone, and the precipitate is collected by filtration, washed with an ethanol / water mixed solution for three times, redissolved in deionized water, and freeze-dried to obtain a second compound;

[0042] S13. 100 mg of the second compound is dissolved in 50 mL of deionized water, 50 mg of the first compound is added, ultrasonicated for 30 min, and then 50 mg of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 30 mg of N-hydroxysuccinimide are added; after stirring at room temperature for 30 min, 0.1 mL of ethylenediamine is added, and reacted at room temperature for 12 h; the precipitate is collected by centrifugation, washed with deionized water repeatedly for five times, and freeze-dried to obtain the modified chitosan.

[0043] The volume ratio of ethanol to water in the ethanol / water mixed solution is 4:1.

[0044] The preparation method of the modified organic nanosheet includes the following steps:

[0045] S21. 42.0 mg of 1,3,5-triformylphloroglucinol and 49.3 mg of 2,5-diethyl-p-phenylenediamine were respectively dissolved in 5 mL of anhydrous dimethyl sulfoxide, mixed, 0.5 mL of 6 mol / L acetic acid solution was added to the mixed solution, 2 mL of mesitylene was further added, ultrasonic treatment was performed for 5 min, transferred to a polytetrafluoroethylene-lined high-pressure reaction kettle, and reacted at 120°C for 72 h. After cooling, the precipitate was collected by centrifugation, washed and extracted with anhydrous N,N-dimethylformamide and acetone by a Soxhlet extractor for 48 h, then dispersed in deionized water, and subjected to probe ultrasonic treatment (power 500 W, ultrasonic treatment for 2 s, interval 3 s) in an ice water bath for 1 h to exfoliate into nanosheets. The unexfoliated thick-layer material was removed by centrifugation, the supernatant was collected and freeze-dried to obtain a third compound;

[0046] S22. 100 mg of the third compound was dispersed in 20 mL of anhydrous N,N-dimethylformamide, 0.5 mL of triethylamine was added, followed by slow dropwise addition of 0.3 mL of 1,4-butanediol sulfite, and the mixture was stirred at 80°C for 24 h under nitrogen protection. After the reaction was completed, the precipitate was collected by centrifugation, washed with anhydrous N,N-dimethylformamide and methanol alternately for five times, then dispersed in deionized water, dialyzed for 72 h (molecular weight cut-off 3500), and freeze-dried to obtain a fourth compound.

[0047] S23. 80 mg of 4-carboxyphthalic anhydride was dissolved in 10 mL of anhydrous N,N-dimethylformamide, 60 mg of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 40 mg of N-hydroxysuccinimide were added, and the mixture was stirred at room temperature for 1 h for activation. Then, 50 mg of the fourth compound and 0.1 mL of triethylamine were added, the mixture was stirred at 50°C for 24 h, and after the reaction was completed, the precipitate was collected by centrifugation, washed with anhydrous N,N-dimethylformamide and acetone alternately for five times, and dried under vacuum at 60°C for 12 h to obtain modified organic nanosheets.

[0048] The preparation method of the bamboo charcoal antibacterial and odor-removing latex paint comprises the following steps:

[0049] S31. Preparation of slurry: In a clean dispersion cylinder, add deionized water according to the formula, under the stirring of 300-400 rpm, add ethylene oxide / propylene oxide block copolymer, polyacrylate ammonium salt dispersant, non-ionic wetting agent and half of the amount of mineral oil defoamer in turn, continue stirring for 10-15 min to ensure that all the additives are completely dissolved and dispersed, slowly add calcined kaolin, stir until there is no obvious dry powder, increase the stirring speed to 1200-1500 rpm, slowly and uniformly add rutile titanium dioxide, nano bamboo charcoal powder, heavy calcium carbonate, and continue stirring for 20-25 min, reduce the stirring speed to 500 rpm, slowly add 2-amino-2-methyl-1-propanol, adjust the pH to 8.0-9.0, and obtain the slurry (if the slurry temperature rises due to high-speed dispersion, it needs to be cooled to below 40°C through water bath cooling or low-speed stirring before the next step to prevent the emulsion from breaking after adding the emulsion);

[0050] S32. Adjust the paint: keep the stirring speed at 400-600 rpm, slowly add the acrylate copolymer emulsion, stir for 5-8 min to mix it evenly with the slurry, slowly and uniformly add modified chitosan and modified organic nanosheet, continue stirring for 15-20 min to ensure uniform distribution, add dodecanol ester, the remaining half of the mineral oil defoamer, isothiazolinone complex preservative, and zinc pyrithione (stir for 3-5 min after adding each additive before adding the next one) in turn; slowly add 2% hydroxyethyl cellulose aqueous solution to adjust the viscosity, and then slowly add hydrophobically modified polyurethane, take a sample to detect the pH (which should be controlled at 8.5-9.5), viscosity, fineness and other indicators, and after passing the test, filter it with a 120 mesh sieve, package, and obtain a bamboo charcoal antibacterial and odor-removing latex paint. The preparation process is shown in Figure 1 .

[0051] Example 2: This example discloses a bamboo charcoal antibacterial and odor-removing latex paint, which comprises the following components in parts by weight: 25 parts of nano bamboo charcoal powder, 12 parts of modified chitosan, 10 parts of modified organic nanosheet, 2.0 parts of ethylene oxide / propylene oxide block copolymer, and 3.0 parts of hydrophobically modified polyurethane.

[0052] The modified chitosan and the modified organic nanosheet form a phthalimide bond.

[0053] The ethylene oxide / propylene oxide block copolymer includes Pluronic® PE 10500, and the hydrophobically modified polyurethane includes Acrysol™ RM-2020 NPR.

[0054] Also included are the following components in parts by weight: 5.0 parts of polyacrylate ammonium salt dispersant, 1.0 part of non-ionic wetting agent, 1.5 parts of mineral oil-based antifoam agent, 180 parts of rutile titanium dioxide, 100 parts of heavy calcium carbonate, 40 parts of calcined kaolin, 1.0 part of 2-amino-2-methyl-1-propanol; 280 parts of acrylate copolymer emulsion; 8.0 parts of dodecanol ester; 1.0 part of isothiazolinone complex preservative; 0.8 part of zinc pyrithione; 30 parts of 2% hydroxyethyl cellulose aqueous solution; 180 parts of deionized water.

[0055] The other components and the preparation method are the same as those in Example 1.

[0056] Example 3: This example discloses a bamboo charcoal antibacterial and odor-removing latex paint, which comprises the following components in parts by weight: 40 parts of nano-sized bamboo charcoal powder, 18 parts of modified chitosan, 15 parts of modified organic nanosheet, 3.5 parts of ethylene oxide / propylene oxide block copolymer, 5.0 parts of hydrophobically modified polyurethane.

[0057] The modified chitosan and the modified organic nanosheet form a phthalimide bond.

[0058] The ethylene oxide / propylene oxide block copolymer comprises Pluronic® PE 10500, and the hydrophobically modified polyurethane comprises Acrysol™ RM-2020 NPR.

[0059] Also included are the following components in parts by weight: 7.0 parts of polyacrylate ammonium salt dispersant, 1.8 parts of non-ionic wetting agent, 2.5 parts of mineral oil-based antifoam agent, 220 parts of rutile titanium dioxide, 140 parts of heavy calcium carbonate, 70 parts of calcined kaolin, 2.0 parts of 2-amino-2-methyl-1-propanol; 320 parts of acrylate copolymer emulsion; 12.0 parts of dodecanol ester; 1.5 parts of isothiazolinone complex preservative; 1.2 parts of zinc pyrithione; 50 parts of 2% hydroxyethyl cellulose aqueous solution; 220 parts of deionized water.

[0060] The other components and the preparation method are the same as those in Example 1.

[0061] Example 4: This example discloses a bamboo charcoal antibacterial and odor-removing latex paint, which comprises the following components in parts by weight: 32.5 parts of nano-sized bamboo charcoal powder, 15 parts of modified chitosan, 12.5 parts of modified organic nanosheet, 2.75 parts of ethylene oxide / propylene oxide block copolymer, 4.0 parts of hydrophobically modified polyurethane.

[0062] The modified chitosan and the modified organic nanosheet form a phthalimide bond.

[0063] The ethylene oxide / propylene oxide block copolymer includes Pluronic® PE 10500, and the hydrophobically modified polyurethane includes Acrysol™ RM-2020 NPR.

[0064] The other components and the preparation method are the same as those in Example 1.

[0065] The other components and the preparation method are the same as those in Example 1.

[0066] Comparative Example 1: Based on Example 1, the difference between Example 1 and the comparative example is that the modified chitosan in the comparative example does not introduce an aluminum-based metal organic framework.

[0067] The preparation method of the modified chitosan includes the following steps:

[0068] S11. 1.0 g of chitosan powder is dissolved in 100 mL of a 2% by mass aqueous acetic acid solution, stirred until completely dissolved, warmed to 60°C, and 10 mL of an aqueous solution containing 3.0 g of 2,3-epoxypropyltrimethylammonium chloride is added dropwise under stirring, reacted for 8 h, the pH is adjusted to neutral with a sodium hydroxide solution, poured into excess acetone, the precipitate is collected by filtration, redissolved in deionized water after washing with an ethanol / water mixed solution three times, and freeze-dried to obtain a second compound;

[0069] S12. 100 mg of the second compound is dissolved in 50 mL of deionized water, ultrasonicated for 30 min, 50 mg of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 30 mg of N-hydroxysuccinimide are added, stirred at room temperature for 30 min, 0.1 mL of ethylenediamine is added, reacted at room temperature for 12 h, the precipitate is collected by centrifugation, washed repeatedly with deionized water five times, and freeze-dried to obtain the modified chitosan.

[0070] The other components and the preparation method are the same as those in Example 1.

[0071] Comparative Example 2: Based on Example 1, the difference between Example 1 and the comparative example is that the modified chitosan in the comparative example does not graft a quaternary ammonium salt.

[0072] The preparation method of the modified chitosan includes the following steps:

[0073] S11. Dissolve 0.94 g aluminum nitrate nonahydrate in 30 mL deionized water to obtain solution A; dissolve 0.35 g trimesic acid in 30 mL anhydrous ethanol to obtain solution B; under vigorous stirring, quickly pour solution B into solution A, transfer to a high-pressure reaction kettle lined with polytetrafluoroethylene, react at 120°C for 12 h, after natural cooling to room temperature, centrifugally collect the precipitate, centrifugally wash with anhydrous ethanol and deionized water alternately for three times, dry in a vacuum oven at 60°C overnight to obtain a first compound;

[0074] S12. Dissolve 100 mg chitosan powder in 50 mL deionized water, add 50 mg of the first compound, ultrasonic for 30 min, then add 50 mg N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 30 mg N-hydroxysuccinimide, stir at room temperature for 30 min, add 0.1 mL ethylenediamine, react at room temperature for 12 h, centrifugally collect the precipitate, repeatedly centrifugally wash with deionized water for five times, freeze-dry to obtain modified chitosan.

[0075] Other components and preparation methods are the same as in Example 1.

[0076] Comparative Example 3: based on Example 1, different from Example 1 is that in the present comparative example, the modified chitosan does not introduce primary amine groups.

[0077] The preparation method of the modified chitosan comprises the following steps:

[0078] S11. Dissolve 0.94 g aluminum nitrate nonahydrate in 30 mL deionized water to obtain solution A; dissolve 0.35 g trimesic acid in 30 mL anhydrous ethanol to obtain solution B; under vigorous stirring, quickly pour solution B into solution A, transfer to a high-pressure reaction kettle lined with polytetrafluoroethylene, react at 120°C for 12 h, after natural cooling to room temperature, centrifugally collect the precipitate, centrifugally wash with anhydrous ethanol and deionized water alternately for three times, dry in a vacuum oven at 60°C overnight to obtain a first compound;

[0079] S12. Dissolve 1.0 g chitosan powder in 100 mL 2% mass fraction acetic acid aqueous solution, stir until completely dissolved, warm to 60°C, under stirring, dropwise add 10 mL aqueous solution containing 3.0 g 2,3-epoxypropyltrimethylammonium chloride, react for 8 h, adjust pH to neutral with sodium hydroxide solution, pour into excess acetone, filter to collect the precipitate, redissolve in deionized water after washing with ethanol / water mixed solution for three times, freeze-dry to obtain a second compound;

[0080] S13. 100 mg of the second compound was dissolved in 50 mL of deionized water, 50 mg of the first compound was added, ultrasonic treatment was performed for 30 min, the precipitate was collected by centrifugation, and the precipitate was repeatedly washed with deionized water for five times, and freeze-drying was performed to obtain the modified chitosan.

[0081] The other components and the preparation method were the same as in Example 1.

[0082] Comparative Example 4: based on Example 1, different from Example 1, in the comparative example, the modified organic nanosheet does not introduce sulfonic acid groups.

[0083] The preparation method of the modified organic nanosheet comprises the following steps:

[0084] S21. 42.0 mg of 1,3,5-triformylphloroglucinol and 49.3 mg of 2,5-diethyl-p-phenylenediamine were respectively dissolved in 5 mL of anhydrous dimethyl sulfoxide, and then mixed, 0.5 mL of 6 mol / L acetic acid solution was added to the mixed solution, and then 2 mL of mesitylene was added, ultrasonic treatment was performed for 5 min, and then transferred to a polytetrafluoroethylene-lined high-pressure reaction kettle, and reacted at 120°C for 72 h, after cooling, the precipitate was collected by centrifugation, and then washed and extracted with anhydrous N,N-dimethylformamide and acetone through a Soxhlet extractor for 48 h, and then dispersed in deionized water, and then treated with a probe ultrasonic treatment (power 500 W, ultrasonic treatment for 2 s, interval 3 s) for 1 h in an ice water bath to exfoliate into nanosheets, and then the unexfoliated thick-layer material was removed by centrifugation, and then the supernatant was collected and freeze-dried to obtain the third compound;

[0085] S22. 80 mg of 4-carboxyphthalic anhydride was dissolved in 10 mL of anhydrous N,N-dimethylformamide, 60 mg of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 40 mg of N-hydroxysuccinimide were added, and then stirred at room temperature for 1 h for activation, and then 50 mg of the third compound and 0.1 mL of triethylamine were added, and then the temperature was increased to 50°C, and then stirred for 24 h for reaction, and then after the reaction was completed, the precipitate was collected by centrifugation, and then washed with anhydrous N,N-dimethylformamide and acetone alternately for five times, and then dried at 60°C under vacuum for 12 h to obtain the modified organic nanosheet.

[0086] The other components and the preparation method were the same as in Example 1.

[0087] Comparative Example 5: based on Example 1, different from Example 1, in the comparative example, the modified organic nanosheet does not introduce phthalic anhydride groups.

[0088] The preparation method of the modified organic nanosheet comprises the following steps:

[0089] S21. 42.0 mg of 1,3,5-triformylphloroglucinol and 49.3 mg of 2,5-diethyl-p- phenylenediamine were separately dissolved in 5 mL of anhydrous dimethyl sulfoxide, mixed, 0.5 mL of 6 mol / L acetic acid solution was added to the mixed solution, 2 mL of mesitylene was further added, and ultrasonic treatment was performed for 5 min. The mixture was transferred to a polytetrafluoroethylene-lined high-pressure reaction vessel and reacted at 120°C for 72 h. After cooling, the precipitate was collected by centrifugation, and washed with anhydrous N,N-dimethylformamide and acetone by a Soxhlet extractor for 48 h. The resulting product was dispersed in deionized water, and probe sonication (power 500 W, 2 sec of sonication and 3 sec of interval) was performed for 1 h in an ice water bath to exfoliate the product into nanosheets. The unexfoliated bulk material was removed by centrifugation, and the supernatant was collected and freeze-dried to obtain a third compound.

[0090] S22. 100 mg of the third compound was dispersed in 20 mL of anhydrous N,N- dimethylformamide, 0.5 mL of triethylamine was added, and then 0.3 mL of 1,4-butane sultone was slowly added dropwise. The mixture was warmed to 80°C and stirred for 24 h under nitrogen protection. After the reaction was completed, the precipitate was collected by centrifugation, washed with anhydrous N,N-dimethylformamide and methanol alternately for five times, and then dispersed in deionized water. The product was dialyzed for 72 h (molecular weight cut-off 3500) and freeze-dried to obtain modified organic nanosheets.

[0091] The other components and the preparation method were the same as in Example 1.

[0092] Comparative Example 6: Based on Example 1, the difference from Example 1 is that the comparative example does not include modified chitosan.

[0093] Comparative Example 7: Based on Example 1, the difference from Example 1 is that the comparative example does not include modified organic nanosheets.

[0094] Comparative Example 8: Based on Example 1, the difference from Example 1 is that the comparative example does not include modified chitosan and modified organic nanosheets.

[0095] Comparative Example 9: Based on Example 1, the difference from Example 1 is that the comparative example does not include ethylene oxide / propylene oxide block copolymer.

[0096] Comparative Example 10: Based on Example 1, the difference from Example 1 is that the comparative example does not include hydrophobically modified polyurethane.

[0097] Comparative Example 11: Based on Example 1, the difference from Example 1 is that the comparative example does not include ethylene oxide / propylene oxide block copolymer and hydrophobically modified polyurethane.

[0098] Comparative Example 12: Based on Example 1, different from Example 1 is that this comparative example does not include modified chitosan, modified organic nanoplatelets, ethylene oxide / propylene oxide block copolymer and hydrophobically modified polyurethane.

[0099] Test Example 1: The latex paint samples obtained from Examples 1-4 and Comparative Examples 1-8 were uniformly coated on cement boards at the same wet film thickness (150 pm) with at least 3 parallel samples per group, and after 7 days of maintenance under standard conditions, the accelerated alkali return test was performed; test conditions: the coated experimental group boards were placed in a constant temperature and humidity chamber (temperature 40 °C, humidity 90%), and a small amount of deionized water was sprayed on the board surface every 8 hours to simulate a humid environment, which lasted for 14 days; the results are shown in Table 1. Figure 2 Figure for effect comparison of Comparative Example 1 and Example 1.

[0100] Test indicators are as follows:

[0101] 1. Visual observation: observe the film state every day, such as whether there is blistering, powdering, peeling, discoloration, etc.

[0102] 2. Adhesion test: after the experiment, use the crosshatch method (ASTM D3359) to test the adhesion, and record the 0B-5B grade.

[0103] 3. Mass change: weigh the mass change of the board before and after the experiment, and calculate the mass loss rate caused by the damage of the paint film.

[0104] Table 1: Simulated alkali return paint film integrity test

[0105]

[0106] According to the results of Table 1, Example 1 can be concluded that the modified chitosan does not introduce aluminum-based metal organic framework, cannot fix calcium ions and potassium ions, and the paint film is severely damaged; Example 1 can be concluded that the modified chitosan does not graft quaternary ammonium salt, cannot effectively fix anions such as chloride ions, ion osmotic pressure imbalance, leading to foaming and damage, compared with Comparative Example 2; Example 1 can be concluded that the modified chitosan does not introduce primary amine group or the modified organic nanosheet does not introduce phthalic anhydride group, both of which cannot form phthalimide bond, the intelligent response mechanism is invalid, and the modified substance cannot be locked and released, compared with Comparative Examples 3 and 5; Example 1 can be concluded that the modified organic nanosheet does not introduce sulfonic acid group, neutralization of hydroxide ion is slow, and the duration of alkaline environment is long, and the paint film is obviously pulverized, compared with Comparative Example 4; Example 1 can be concluded that only one kind of modified substance, the paint film is severely pulverized, compared with Comparative Examples 6 and 7; Example 1 can be concluded that without modified chitosan and modified organic nanosheet, the paint film only relies on itself to resist, and completely fails, compared with Comparative Example 8. Compared with Comparative Examples 6 and 7, Comparative Examples 3 and 5 do not form phthalimide bond, and the particles of the modified substance that cannot be bonded are only physically mixed in the paint film, which has poor compatibility with the surrounding film-forming material, weak interfacial bonding force, and higher damage degree of the paint film.

[0107] Test Example 2: The latex paint samples obtained in Examples 1-4 and Comparative Examples 9-12 were placed in sealed paint cans and placed in a constant temperature oven at 50°C for accelerated aging (about 1 month at room temperature for 1 day), and the samples were taken out for detection at 30 days. The results are shown in Table 2.

[0108] The test indicators are as follows:

[0109] 1. Sample state: observe whether it is layered, watered, flocculated, caked, settled.

[0110] 2. Viscosity change: measure the viscosity (KU value) using a rotational viscometer, and calculate the viscosity change rate. The viscosity change of a sample with good stability should be small.

[0111] 3. Scraper fineness: evaluate the generation of flocculated particles using a scraper fineness meter.

[0112] Table 2 Anti-flocculation and demulsification detection

[0113]

[0114] According to the results of Table 2, Example 1 can be concluded that no ethylene oxide / propylene oxide block copolymer, lack of steric hindrance layer, electrostatic flocculation occurs compared with Comparative Example 9; Example 1 can be concluded that no hydrophobic modified polyurethane, lack of three-dimensional network binding, particles slowly settle under gravity, insufficient system structure strength, soft settlement easy to re-stir, slight water separation compared with Comparative Example 10; Example 1 can be concluded that no ethylene oxide / propylene oxide block copolymer and hydrophobic modified polyurethane, neither steric hindrance layer nor network locking, system completely unstable, serious flocculation, hard precipitation, complete demulsification compared with Comparative Example 11; Example 1 can be concluded that no modified chitosan, modified organic nanosheet, ethylene oxide / propylene oxide block copolymer and hydrophobic modified polyurethane, system uniform and stable compared with Comparative Example 12.

[0115] Test Example 3: The latex paint obtained in Examples 1-4 was subjected to antibacterial performance test (referring to national standard GB / T21866-2008); odor performance test (referring to standard JC / T 1074-2008); adhesion (referring to standard GB / T 9286-2021 grid method, 0-5B level, 5B best); scrub resistance (referring to standard GB / T 9266-2021); contrast ratio (referring to standard GB / T 23981.1-2019, measuring hiding power, the closer the value to 1, the stronger the hiding power); the results are shown in Table 3.

[0116] Table 3 Basic performance test of latex paint

[0117]

[0118] Finally, it should be noted that although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or equivalently replace part of the technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A bamboo charcoal antibacterial and odor-neutralizing latex paint, characterized in that, The composition comprises the following components in parts by weight: 25-40 parts of nanoscale bamboo charcoal powder, 12-18 parts of modified chitosan, 10-15 parts of modified organic nanosheet, 2.0-3.5 parts of ethylene oxide / propylene oxide block copolymer, and 3.0-5.0 parts of hydrophobically modified polyurethane. The modified chitosan and the modified organic nanosheet form a phthalimide bond. The preparation method of the modified chitosan comprises the following steps: S11. Dissolve aluminum nitrate nonahydrate in deionized water to obtain solution A; dissolve trimesic acid in anhydrous ethanol to obtain solution B; under vigorous stirring, quickly pour solution B into solution A, transfer to a high-pressure reaction kettle for reaction, naturally cool to room temperature, centrifuge to collect the precipitate, wash with anhydrous ethanol and deionized water alternately, dry in a vacuum oven overnight to obtain a first compound; S12. Dissolve chitosan powder in an aqueous acetic acid solution with a mass fraction of 2%, stir until completely dissolved, heat, and under stirring, add an aqueous solution of 2,3-epoxypropyltrimethylammonium chloride dropwise, adjust the pH to neutral, pour into excess acetone, filter to collect the precipitate, wash with an ethanol / water mixed solution, then redissolve in deionized water, freeze-dry to obtain a second compound; S13. Dissolve the second compound in deionized water, add the first compound, ultrasonic, then add N-(3-dimethylaminopropyl)-N'-ethyl carbodiimide hydrochloride and N-hydroxysuccinimide, stir at room temperature, add ethylenediamine, react at room temperature, centrifuge to collect the precipitate, repeatedly centrifuge to wash with deionized water, and freeze-dry to obtain the modified chitosan; The preparation method of the modified organic nanosheet comprises the following steps: S21. Dissolve 1,3,5-triformylphloroglucinol and 2,5-diethyl-p-phenylenediamine in anhydrous dimethyl sulfoxide respectively, then mix, add 6 mol / L acetic acid solution to the mixed solution, then add mesitylene, ultrasonic, transfer to a high-pressure reaction kettle for reaction, cool, centrifuge to collect the precipitate, continuously wash and extract with anhydrous N,N-dimethylformamide and acetone through a Soxhlet extractor, then disperse in deionized water, perform probe ultrasonic treatment in an ice water bath, centrifuge, collect the supernatant and freeze-dry to obtain a third compound; S22. Disperse the third compound in anhydrous N,N-dimethylformamide, add triethylamine, then slowly drop 1,4-butanesultam, heat, stir and react under nitrogen protection, after the reaction is completed, centrifuge to collect the precipitate, alternately wash with anhydrous N,N-dimethylformamide and methanol, then disperse in deionized water, dialyze, and freeze-dry to obtain a fourth compound; S23. Dissolve 4-carboxyphthalic anhydride in anhydrous N,N-dimethylformamide, add N-(3-dimethylaminopropyl)-N'-ethyl carbodiimide hydrochloride and N-hydroxysuccinimide, stir and activate at room temperature, then add the fourth compound and triethylamine, heat, stir and react, after the reaction is completed, centrifuge to collect the precipitate, alternately wash with anhydrous N,N-dimethylformamide and acetone, and vacuum dry to obtain the modified organic nanosheet.

2. The bamboo charcoal antibacterial and odor-removing latex paint according to claim 1, characterized in that, The ethylene oxide / propylene oxide block copolymer includes Pluronic® PE 10500, and the hydrophobically modified polyurethane includes Acrysol™ RM-2020 NPR.

3. The bamboo charcoal antibacterial and odor-removing latex paint according to claim 1, characterized in that, The components further include the following components in parts by weight: 5.0-7.0 parts of polyacrylate ammonium salt dispersant, 1.0-1.8 parts of non-ionic wetting agent, 1.5-2.5 parts of mineral oil-based defoamer, 180-220 parts of rutile titanium dioxide, 100-140 parts of heavy calcium carbonate, 40-70 parts of calcined kaolin, 1.0-2.0 parts of 2-amino-2-methyl-1-propanol; 280-320 parts of acrylate copolymer emulsion; 8.0-12.0 parts of dodecanol ester; 1.0-1.5 parts of isothiazolinone complex preservative; 0.8-1.2 parts of zinc pyrithione; 30-50 parts of 2% hydroxyethyl cellulose aqueous solution; 180-220 parts of deionized water.

4. The bamboo charcoal antibacterial and odor-removing latex paint according to claim 3, characterized in that, The polyacrylate ammonium salt dispersant includes SN-5027; the non-ionic wetting agent includes Dynol 604; the mineral oil-based defoamer includes DF-877 from Defeng Chemical; the acrylate copolymer emulsion includes Primal™ AC-261; and the isothiazolinone complex preservative includes KATHON® LX-150.

5. The bamboo charcoal antibacterial and odor-removing latex paint according to claim 1, characterized in that, The volume ratio of ethanol to water in the ethanol / water mixed solution is 4:

1.

6. A preparation method of the bamboo charcoal antibacterial and odor-removing emulsion paint according to any one of claims 1 to 5, characterized in that, The preparation method includes the following steps: S31. Preparing a slurry: in a dispersion cylinder, deionized water is added, and under stirring, ethylene oxide / propylene oxide block copolymer, polyacrylate ammonium salt dispersant, non-ionic wetting agent, and half of the amount of mineral oil-based defoamer are sequentially added, stirring is continued to ensure that all the additives are completely dissolved and dispersed, calcined kaolin is slowly added, stirring is continued until there are no obvious dry powder lumps, the stirring speed is increased, and rutile titanium dioxide, nanoscale bamboo charcoal powder, and heavy calcium carbonate are slowly and uniformly added, the stirring speed is then reduced, 2-amino-2-methyl-1-propanol is slowly added, the pH is adjusted to 8.0-9.0, and a slurry is obtained; S32. Adjusting the paint: while stirring, acrylate copolymer emulsion is slowly added and mixed uniformly with the slurry, modified chitosan and modified organic nanosheets are slowly and uniformly added, stirring is continued to ensure uniform distribution, dodecanol ester, the remaining half of the mineral oil-based defoamer, isothiazolinone complex preservative, and zinc pyrithione are sequentially added, each additive is stirred for 3-5 min before the next additive is added, 2% hydroxyethyl cellulose aqueous solution is slowly added, and hydrophobically modified polyurethane is slowly added dropwise, a sample is taken for testing, the paint is filtered and packaged after passing the test, and a bamboo charcoal antibacterial and odor-removing latex paint is obtained.

Images