Bamboo charcoal purifying multifunctional interior wall latex paint and preparation method thereof

Abstract

The application discloses a kind of bamboo charcoal purification multifunctional interior wall latex paint and preparation method thereof, belong to coating field, including the following weight fraction components: 200 parts of vinyl emulsion, 40-45 parts of modified bamboo charcoal powder, 8-10 parts of dispersing agent, 120-130 parts of nano filler, 80-90 parts of deionized water and other auxiliary agents;Modified bamboo charcoal powder is with bamboo powder, LDH precursor, ZIF-8 precursor, hydrophobic modifier as main raw material by 25 DEG C-600 DEG C multi-section calcination and prepared composite material.The bamboo powder of the application, ZIF-8 precursor is prepared with double adsorption system, bamboo charcoal first adsorbs formaldehyde, when reaching the upper limit of adsorption, bamboo charcoal starts to discharge formaldehyde outward, and the discharged formaldehyde will be captured by ZIF-8, solve the problem of formaldehyde secondary pollution.

Description

Technical Field

[0001] This invention belongs to the field of coatings and relates to a bamboo charcoal purifying multifunctional interior wall latex paint and its preparation method. Background Technology

[0002] Carbon-based latex paint is an environmentally friendly coating made by adding bamboo charcoal powder (a byproduct of bamboo charcoal), functional material A, film-forming aids, dispersants, thickeners, etc., with vinyl emulsion as the film-forming substance. The product has extremely low VOC content, and bamboo charcoal powder can efficiently adsorb free formaldehyde in the air, thus achieving the effect of purifying formaldehyde indoors.

[0003] However, bamboo charcoal not only has high adsorption capacity for formaldehyde, but also for moisture and other substances. In a humid environment, moisture will compete with formaldehyde for adsorption, occupying a large number of adsorption sites and reducing the amount of formaldehyde adsorbed by bamboo charcoal. When bamboo charcoal reaches its adsorption limit, it will release a small amount of formaldehyde into the room, causing secondary pollution. Summary of the Invention

[0004] The purpose of this invention is to provide a bamboo charcoal purifying multifunctional interior wall latex paint and its preparation method, which solves the current problem that in humid environments, moisture competes with formaldehyde for adsorption, moisture occupies a large number of adsorption sites, reducing the amount of formaldehyde adsorbed by bamboo charcoal, and when bamboo charcoal reaches its adsorption limit, it releases a small amount of formaldehyde into the room, causing secondary pollution.

[0005] The technical solution adopted in this invention is as follows: A bamboo charcoal purifying multifunctional interior wall latex paint comprises the following components in parts by weight: 200 parts vinyl emulsion, 40-45 parts modified bamboo charcoal powder, 8-10 parts dispersant, 120-130 parts nano filler, 80-90 parts deionized water and other additives. The modified bamboo charcoal powder is a composite material prepared by multi-stage calcination at 25℃-600℃ using bamboo powder, LDH precursor, ZIF-8 precursor, and hydrophobic modifier as the main raw materials.

[0006] This invention prepares a dual adsorption system using bamboo powder and ZIF-8 precursor as raw materials. Bamboo charcoal, obtained from calcined bamboo powder, is the main adsorption component, possessing a multi-level pore structure ranging from macropores to mesopores. The proportion of macropores is greater than that of ZIF-8, whose pores are generally micropores. The larger pores provide a rapid diffusion channel for gases, thus bamboo charcoal preferentially adsorbs formaldehyde from the air. Due to the difference in pore size, the two components exhibit preferential adsorption. Bamboo charcoal first adsorbs formaldehyde, and once it reaches its adsorption limit, it begins to release formaldehyde, which is then captured by ZIF-8. To ensure ZIF-8 can quickly capture the released formaldehyde, this application directly uses ZIF-8 precursor and bamboo powder as raw materials during the preparation of bamboo charcoal powder. This results in a tight composite of the two adsorption systems, reducing adsorption delay due to spatial barriers and preventing formaldehyde released from bamboo charcoal from escaping into the air. Furthermore, this application modifies the entire adsorption system using a hydrophobic modifier, reducing the overall water adsorption capacity and increasing the overall formaldehyde adsorption capacity.

[0007] Based on the bamboo charcoal-ZIF-8 dual adsorption system, this application incorporates LDH (layered double metal hydroxide). In the bamboo charcoal-ZIF-8 dual adsorption system, ZIF-8 is loaded onto bamboo charcoal; however, this is merely a physical loading process, and the loading relationship between the two is unstable during the subsequent latex paint preparation, easily leading to separation. Therefore, this application adds LDH to the dual adsorption system, forming a ZIF-8@LDH / bamboo charcoal ternary system after multi-stage calcination. The metal ions on the LDH layers undergo an anchoring reaction with the oxygen-containing functional groups on the bamboo charcoal surface; the OH groups on the LDH layers... - It coordinates with the metal ions in ZIF-8; the LDH layer acts as an intermediate bridge to anchor ZIF-8 to bamboo charcoal, transforming the physical loading relationship of the bamboo charcoal-ZIF-8 dual adsorption system into chemical anchoring, thus solving the problem of unstable connection in the bamboo charcoal-ZIF-8 dual adsorption system; based on solving this problem, LDH can also adsorb some acidic gases in the air, improving the purification effect of latex paint.

[0008] Furthermore, based on the total amount of modified bamboo charcoal powder, the modified bamboo charcoal powder comprises the following components in parts by weight: 60-70 parts bamboo powder, 20-22 parts LDH precursor, 18-20 parts ZIF-8 precursor, and 10-15 parts hydrophobic modifier.

[0009] Furthermore, the LDH precursor comprises magnesium nitrate, aluminum nitrate, and urea, with a mass ratio of magnesium nitrate, aluminum nitrate, and urea of ​​6:3:5.

[0010] Furthermore, the ZIF-8 precursor comprises zinc nitrate hexahydrate and 2-methylimidazole, with a mass ratio of zinc nitrate hexahydrate to 2-methylimidazole of 10:13.

[0011] Furthermore, the hydrophobic modifier is hexamethyldisilazane.

[0012] Furthermore, the modified bamboo charcoal powder is prepared by the following method: S1.1 A ZIF-8@LDH / bamboo fiber composite was prepared using bamboo powder, LDH precursor, and ZIF-8 precursor as the main raw materials. S1.2, Multi-stage calcination of ZIF-8@LDH / bamboo fiber composite: First stage of calcination: ZIF-8@LDH / bamboo fiber composite was heated from 25℃ to 250℃ in a tube furnace under nitrogen atmosphere at a heating rate of 2℃ / min, and held at 250℃ for 1 hour. Second stage calcination: Under nitrogen atmosphere, the temperature is increased from 250℃ to 600℃ at a rate of 5℃ / min, and held at 600℃ for 2 hours; Third stage of calcination: Subsequently, at 600℃, the atmosphere was switched to a nitrogen atmosphere containing 3% water vapor by volume, and the temperature was maintained for 30 minutes. Fourth stage calcination: Finally, the gas atmosphere was switched to inert argon, and the system was cooled from 600℃ to 150℃. A hydrophobic modifier was introduced at 150℃, and the reaction was carried out for 1 hour to obtain the calcined composite. S1.3 After the calcined composite is cooled to room temperature, it is pulverized to obtain modified bamboo charcoal powder.

[0013] This application involves multi-stage calcination, during which bamboo powder, LDH precursor, ZIF-8 precursor, and hydrophobic modifier react to form a stable hydrophobically modified ZIF-8@LDH / bamboo charcoal ternary system with a stable pore structure.

[0014] Furthermore, the dispersant comprises polycarboxylate dispersant DS707 and isomeric tridecyl alcohol polyoxyethylene ether in a mass ratio of 6:1.

[0015] Furthermore, the nanofiller includes nano-sized calcined kaolin, stearic acid modified nano-calcium carbonate, nano-titanium dioxide, and nano-silica; The mass ratio of nano-calcined kaolin, stearic acid-modified nano-calcium carbonate, nano-titanium dioxide, and nano-silica is 1:2:2:1.

[0016] Further, the other additives include 8-10 parts thickener, 3-5 parts film-forming aid, and 1-3 parts defoamer; wherein the thickener includes at least one of polyurethane associative thickener, hydroxyethyl cellulose, and acrylate thickener; the film-forming aid is dodecyl alcohol ester; and the defoamer is defoamer DF7010.

[0017] A method for preparing a bamboo charcoal purifying multifunctional interior wall latex paint includes the following steps: S1. Prepare modified bamboo charcoal powder for later use; S2. Under low-speed stirring, dispersant and nanofiller are added sequentially to deionized water. After the addition is completed, the mixture is dispersed at high speed to obtain a primary slurry. S3. While stirring, vinyl emulsion, modified bamboo charcoal powder and other additives are added to the primary slurry in sequence. After continuous stirring until uniform, bamboo charcoal purification multifunctional interior wall latex paint is obtained; wherein, the vinyl emulsion is vinyl acetate-ethylene copolymer emulsion.

[0018] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. This invention relates to a multifunctional bamboo charcoal purifying interior wall latex paint. Through multi-stage calcination, bamboo powder, LDH precursor, ZIF-8 precursor, and hydrophobic modifier react to form a stable hydrophobically modified ZIF-8@LDH / bamboo charcoal ternary system. The bamboo charcoal first adsorbs formaldehyde. When the adsorption limit is reached, the bamboo charcoal begins to release formaldehyde to the outside. The released formaldehyde is captured by ZIF-8, which solves the problem of releasing a small amount of formaldehyde into the room and causing secondary pollution when the bamboo charcoal reaches the adsorption limit. 2. In this invention, the ZIF-8@LDH / bamboo charcoal ternary system has been hydrophobically modified, which reduces the adsorption of moisture in a humid environment and relatively improves the adsorption of formaldehyde. 3. This invention incorporates LDH into the dual adsorption system. Metal ions on the LDH plates undergo an anchoring reaction with oxygen-containing functional groups on the surface of bamboo charcoal; OH groups on the LDH plates... - It coordinates with the metal ions in ZIF-8; the LDH layer acts as an intermediate bridge to anchor ZIF-8 to bamboo charcoal, transforming the physical loading relationship of the bamboo charcoal-ZIF-8 dual adsorption system into chemical anchoring, thus solving the problem of unstable connection in the bamboo charcoal-ZIF-8 dual adsorption system; based on solving this problem, LDH can also adsorb some acidic gases in the air, improving the purification effect of latex paint. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is the trend graph for Experiment Example 2; Figure 2 This is a usage diagram within the scope of Embodiment 4 of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0022] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0023] The features and performance of the present invention will be further described in detail below with reference to embodiments. Example 1

[0024] A preferred embodiment of the present invention provides a bamboo charcoal purifying multifunctional interior wall latex paint, comprising the following components in parts by weight: 200 parts vinyl emulsion, 40 parts modified bamboo charcoal powder, 8 parts dispersant, 120 parts nanofiller, 80 parts deionized water, and other additives; the dispersant comprises polycarboxylate dispersant DS707 and isomeric tridecyl alcohol polyoxyethylene ether in a mass ratio of 6:1; the nanofiller comprises nano-calcined kaolin, stearic acid modified nano-calcium carbonate, nano-titanium dioxide, and nano-silica, wherein the mass ratio of nano-calcined kaolin, stearic acid modified nano-calcium carbonate, nano-titanium dioxide, and nano-silica is 1:2:2:1; the other additives comprise 8 parts thickener, 3 parts film-forming aid, and 1 part defoamer; wherein the thickener is a polyurethane associative thickener; the film-forming aid is dodecyl alcohol ester; and the defoamer is defoamer DF7010.

[0025] Based on the total amount of modified bamboo charcoal powder, the modified bamboo charcoal powder comprises the following components in parts by weight: 60 parts bamboo powder, 20 parts LDH precursor, 18 parts ZIF-8 precursor, and 10 parts hydrophobic modifier.

[0026] The LDH precursor includes magnesium nitrate, aluminum nitrate, and urea, with a mass ratio of magnesium nitrate, aluminum nitrate, and urea of ​​6:3:5.

[0027] The ZIF-8 precursor comprises zinc nitrate hexahydrate and 2-methylimidazole, with a mass ratio of zinc nitrate hexahydrate to 2-methylimidazole of 10:13.

[0028] The hydrophobic modifier is hexamethyldisilazane.

[0029] The above-mentioned method for preparing a bamboo charcoal purifying multifunctional interior wall latex paint includes the following steps: S1. Prepare modified bamboo charcoal powder for later use; the modified bamboo charcoal powder is prepared by the following method: S1.1. Disperse bamboo powder in deionized water, add magnesium nitrate, aluminum nitrate and urea in sequence, and stir to form a uniform suspension; transfer the suspension to a high-pressure reactor and react at 110℃ for 9 hours. After the reaction, cool, wash and dry to obtain LDH / bamboo fiber composite; immerse the LDH / bamboo fiber composite in a methanol solution of zinc nitrate hexahydrate, filter after soaking for 24 hours, and then add it to a methanol solution of 2-methylimidazole. Stir evenly and react for 12 hours. After the reaction, wash and dry to obtain ZIF-8@LDH / bamboo fiber composite. S1.2, Multi-stage calcination of ZIF-8@LDH / bamboo fiber composite: First stage of calcination: ZIF-8@LDH / bamboo fiber composite was heated from 25℃ to 250℃ in a tube furnace under nitrogen atmosphere at a heating rate of 2℃ / min, and held at 250℃ for 1 hour. Second stage calcination: Under nitrogen atmosphere, the temperature is increased from 250℃ to 600℃ at a rate of 5℃ / min, and held at 600℃ for 2 hours; Third stage of calcination: Subsequently, at 600℃, the atmosphere was switched to a nitrogen atmosphere containing 3% water vapor by volume, and the temperature was maintained for 30 minutes. Fourth stage calcination: Finally, the gas atmosphere was switched to inert gas argon, and the system was cooled from 600℃ to 150℃. Hexamethyldisilazane vapor was introduced at 150℃ and reacted for 1 hour to obtain the calcined composite. S1.3 After the calcined composite is cooled to room temperature, it is pulverized to obtain modified bamboo charcoal powder; S2. Under low-speed stirring, dispersant and nanofiller are added sequentially to deionized water. After the addition is completed, the mixture is dispersed at high speed to obtain a primary slurry. S3. While stirring, add vinyl acetate-ethylene copolymer emulsion, modified bamboo charcoal powder and other additives to the primary slurry in sequence, and continue stirring until uniform to obtain bamboo charcoal purification multifunctional interior wall latex paint. Example 2

[0030] Based on Example 1, this preferred embodiment of the present invention provides a bamboo charcoal purifying multifunctional interior wall latex paint, comprising the following components in parts by weight: 200 parts vinyl emulsion, 40 parts modified bamboo charcoal powder, 8 parts dispersant, 120 parts nanofiller, 80 parts deionized water, and other additives; the dispersant includes polycarboxylate dispersant DS707 and isomeric tridecyl alcohol polyoxyethylene ether in a mass ratio of 6:1; the nanofiller includes nano-calcined kaolin, stearic acid modified nano-calcium carbonate, nano-titanium dioxide, and nano-silica, with a mass ratio of 1:2:2:1; the other additives include 8 parts thickener, 3 parts film-forming aid, and 1 part defoamer; wherein the thickener is a polyurethane associative thickener; the film-forming aid is dodecyl alcohol ester; and the defoamer is defoamer DF7010.

[0031] Based on the total amount of modified bamboo charcoal powder, the modified bamboo charcoal powder comprises the following components in parts by weight: 65 parts bamboo powder, 21 parts LDH precursor, 19 parts ZIF-8 precursor, and 13 parts hydrophobic modifier.

[0032] The rest of this embodiment is the same as that in Embodiment 1. Example 3

[0033] Based on Example 1, a preferred embodiment of the present invention provides a bamboo charcoal purifying multifunctional interior wall latex paint, comprising the following components in parts by weight: 200 parts vinyl emulsion, 40 parts modified bamboo charcoal powder, 8 parts dispersant, 120 parts nanofiller, 80 parts deionized water, and other additives; the dispersant comprises polycarboxylate dispersant DS707 and isomeric tridecyl alcohol polyoxyethylene ether in a mass ratio of 6:1; the nanofiller comprises nano-calcined kaolin, stearic acid modified nano-calcium carbonate, nano-titanium dioxide, and nano-silica, wherein the mass ratio of nano-calcined kaolin, stearic acid modified nano-calcium carbonate, nano-titanium dioxide, and nano-silica is 1:2:2:1; the other additives comprise 8 parts thickener, 3 parts film-forming aid, and 1 part defoamer; wherein the thickener is a polyurethane associative thickener; the film-forming aid is dodecyl alcohol ester; and the defoamer is defoamer DF7010.

[0034] Based on the total amount of modified bamboo charcoal powder, the modified bamboo charcoal powder comprises the following components in parts by weight: 70 parts bamboo powder, 22 parts LDH precursor, 20 parts ZIF-8 precursor, and 15 parts hydrophobic modifier.

[0035] The rest of this embodiment is the same as that in Embodiment 1. Example 4

[0036] Based on Example 2, this example differs from Example 2 in that it provides a bamboo charcoal purifying multifunctional interior wall latex paint, comprising the following components in parts by weight: 200 parts vinyl emulsion, 43 parts modified bamboo charcoal powder, 9 parts dispersant, 125 parts nanofiller, 85 parts deionized water, and other additives. The dispersant includes polycarboxylate dispersant DS707 and isomeric tridecyl alcohol polyoxyethylene ether in a mass ratio of 6:1. The nanofiller includes nano-calcined kaolin, stearic acid-modified nano-calcium carbonate, nano-titanium dioxide, and nano-silica, with a mass ratio of 1:2:2:1. The other additives include 9 parts thickener, 4 parts film-forming aid, and 2 parts defoamer. The thickener is a polyurethane associative thickener; the film-forming aid is dodecyl alcohol ester; and the defoamer is defoamer DF7010. The remaining parts of this example are consistent with Example 2. The actual usage diagram within the scope of this embodiment is as follows: Figure 2 As shown, the coating surface is smooth and flat, with no obvious graininess. Example 5

[0037] Based on Example 2, this example differs from Example 2 in that it provides a bamboo charcoal purifying multifunctional interior wall latex paint, comprising the following components in parts by weight: 200 parts vinyl emulsion, 45 parts modified bamboo charcoal powder, 10 parts dispersant, 130 parts nanofiller, 90 parts deionized water, and other additives; the dispersant includes polycarboxylate dispersant DS707 and isomeric tridecyl alcohol polyoxyethylene ether in a mass ratio of 6:1; the nanofiller includes nano-calcined kaolin, stearic acid modified nano-calcium carbonate, nano-titanium dioxide, and nano-silica, with a mass ratio of 1:2:2:1; the other additives include 10 parts thickener, 5 parts film-forming aid, and 3 parts defoamer; wherein the thickener is a polyurethane associative thickener; the film-forming aid is dodecyl alcohol ester; and the defoamer is defoamer DF7010. The rest of this embodiment is the same as that of Embodiment 2.

[0038] Comparative Example 1 Based on Example 4, the difference from Example 4 is that the bamboo charcoal powder in this comparative example is unmodified bamboo charcoal powder, which is bamboo charcoal powder made from four-year-old bamboo carbonized at a high temperature of 800℃; the rest are the same as in Example 4.

[0039] Comparative Example 2 Based on Example 4, the difference from Example 4 is that the bamboo charcoal purifying multifunctional interior wall latex paint provided in this comparative example does not contain modified bamboo charcoal powder; the preparation process does not include the preparation process of modified bamboo charcoal powder, and the rest is the same as in Example 4.

[0040] Comparative Example 3 Based on Example 4, the difference from Example 4 is that the modified bamboo charcoal powder in this comparative example does not contain LDH precursor. Referring to the preparation method of Example 4, the bamboo powder is directly mixed and reacted with ZIF-8 precursor, then subjected to multi-stage calcination, and then cooled and pulverized to obtain ZIF-8 / bamboo charcoal composite as modified bamboo charcoal powder; the rest is the same as in Example 4.

[0041] Comparative Example 4 Based on Example 4, the difference from Example 4 is that the modified bamboo charcoal powder in this comparative example does not contain ZIF-8 precursor. Referring to the preparation method of Example 4, the bamboo powder is directly mixed and reacted with the LDH precursor, then subjected to multi-stage calcination, and then cooled and pulverized to obtain the LDH / bamboo charcoal composite as the modified bamboo charcoal powder; the rest is the same as in Example 4.

[0042] Comparative Example 5 Based on Example 4, but unlike Example 4, the modified bamboo charcoal powder in this comparative example is not subjected to multi-stage calcination during preparation. The ZIF-8@LDH / bamboo fiber composite is calcined in a tube furnace under a nitrogen atmosphere by introducing hexamethyldisilazane vapor and directly heating it to 600°C. After calcination for 5 hours, it is cooled and pulverized to obtain the modified bamboo charcoal powder.

[0043] Comparative Example 6 Based on Example 4, but unlike Example 4, the modified bamboo charcoal powder in this comparative example did not undergo a first-stage calcination during preparation. The ZIF-8@LDH / bamboo fiber composite was heated in a tube furnace under a nitrogen atmosphere at a rate of 5°C / min, from 25°C to 600°C, and held at 600°C for 2 hours. Subsequently, at 600°C, the atmosphere was switched to a nitrogen atmosphere containing 3% water vapor by volume, and held for 30 minutes. Finally, the gas atmosphere was switched to an inert gas argon, and the system was cooled from 600°C to 150°C. Hexamethyldisilazane vapor was introduced at 150°C, and the reaction was carried out for 1 hour to obtain the calcined composite. After the calcined composite was cooled to room temperature, it was pulverized to obtain the modified bamboo charcoal powder.

[0044] Comparative Example 7 Based on Example 4, but unlike Example 4, the modified bamboo charcoal powder in this comparative example does not undergo a second calcination during preparation. The ZIF-8@LDH / bamboo fiber composite is heated from 25°C to 250°C in a tube furnace under a nitrogen atmosphere at a heating rate of 2°C / min, and held at 250°C for 1 hour. Then, the temperature is increased from 250°C to 600°C at a rate of 5°C / min. Subsequently, at 600°C, the atmosphere is switched to a nitrogen atmosphere containing 3% water vapor by volume, and held for 30 minutes. Finally, the gas atmosphere is switched to an inert gas argon, and the system is cooled from 600°C to 150°C. Hexamethyldisilazane vapor is introduced at 150°C, and the reaction is carried out for 1 hour to obtain the calcined composite. After the calcined composite is cooled to room temperature, it is pulverized to obtain modified bamboo charcoal powder.

[0045] Comparative Example 8 Based on Example 4, but unlike Example 4, the modified bamboo charcoal powder in this comparative example does not undergo a third-stage calcination during preparation. The ZIF-8@LDH / bamboo fiber composite is heated from 25°C to 250°C in a tube furnace under a nitrogen atmosphere at a heating rate of 2°C / min, and held at 250°C for 1 hour. Under a nitrogen atmosphere, the temperature is then increased from 250°C to 600°C at a rate of 5°C / min, and held at 600°C for 2 hours. Finally, the gas atmosphere is switched to the inert gas argon, and the system is cooled from 600°C to 150°C. Hexamethyldisilazane vapor is introduced at 150°C, and the reaction is carried out for 1 hour to obtain the calcined composite. After the calcined composite is cooled to room temperature, it is pulverized to obtain the modified bamboo charcoal powder.

[0046] Comparative Example 9 (without hydrophobic modification) Based on Example 4, but unlike Example 4, the modified bamboo charcoal powder in this comparative example does not undergo a fourth stage of calcination during preparation. The ZIF-8@LDH / bamboo fiber composite is heated from 25°C to 250°C in a tube furnace under a nitrogen atmosphere at a heating rate of 2°C / min, and held at 250°C for 1 hour. Under a nitrogen atmosphere, the temperature is then increased from 250°C to 600°C at a rate of 5°C / min, and held at 600°C for 2 hours. Subsequently, at 600°C, the atmosphere is switched to a nitrogen atmosphere containing 3% water vapor by volume, and held for 30 minutes to obtain the calcined composite. After the calcined composite is cooled to room temperature, it is pulverized to obtain the modified bamboo charcoal powder.

[0047] Comparative Example 10 Based on Example 4, but unlike Example 4, the dispersant in this comparative example does not include isomeric tridecyl alcohol polyoxyethylene ether. The latex paint layer has a noticeable grainy texture, with a small amount of particles clumping together.

[0048] Comparative Example 11 Based on Example 4, the difference from Example 4 is that the nano-calcium carbonate in this comparative example nanofiller is not modified with stearic acid.

[0049] Experimental Example 1 Formaldehyde adsorption performance was tested, and the latex paints prepared in Examples 1-5 and Comparative Examples 1-11 were tested for their ability to adsorb formaldehyde in a humid environment. Test method: The latex paint sample was evenly coated onto a glass plate (10cm×10cm), dried to form a film, and then placed in a sealed test chamber (1m). 3 The initial formaldehyde concentration inside the cabin was (1.0±0.1) mg / m³. 3 The relative humidity was controlled at (80±5)%, and the temperature at (25±1)℃. The residual formaldehyde concentration in the chamber was tested every 24 hours (24 hours is one testing cycle). After the test, formaldehyde gas of the standard concentration was re-injected to ensure that the initial formaldehyde concentration in the chamber was (1.0±0.1) mg / m³. 3 The next test cycle was conducted (the sample continuously adsorbed formaldehyde); the formaldehyde adsorption rate every 24 hours was: formaldehyde adsorption rate (%) = (initial concentration - remaining concentration) / initial concentration × 100%. The test cycle was 7 days, and the formaldehyde adsorption rate on day 1, day 3 and day 7 was recorded. The results are shown in Table 1 (average value).

[0050] Table 1 Formaldehyde adsorption rate

[0051] The present invention can maintain a high adsorption rate of formaldehyde in a humid environment within 7 days, with an adsorption rate greater than 85%; compared with Example 4 and Comparative Examples 1-4, it can be seen that the ZIF-8@LDH / bamboo charcoal ternary system in this application can significantly improve the adsorption capacity of latex paint for formaldehyde in a humid environment; Comparative Examples 4 and Comparative Examples 5-9 can illustrate that the multi-stage calcination in this application is one of the keys to forming stable channels and ensuring high adsorption.

[0052] Experimental Example 2 Formaldehyde desorption (secondary pollution) detection, the test sample is the same as in test example 1; Detection method: Expose latex paint samples to a high concentration of formaldehyde (initial concentration 5.0 mg / m³). 3 (At 80% humidity), the residual formaldehyde concentration in the test environment was collected every 12 hours, and a trend graph of the residual formaldehyde concentration as a function of adsorption time was plotted (e.g., ...). Figure 1As shown (in the figure), the change trend of the remaining formaldehyde concentration is that it first continuously decreases. After decreasing to a certain extent, it remains in a balanced state for a short period (about 12 hours) (test area), and then continues to decrease until it reaches equilibrium. (Bamboo charcoal preferentially adsorbs. After the bamboo charcoal is saturated with adsorption, the adsorption rate changes very little and tends to equilibrium. After the bamboo charcoal is saturated with adsorption prior to ZIF-8, the adsorption of bamboo charcoal transforms into the adsorption of ZIF-8. This transformation requires a process, and this transformation process is the test area where the bamboo charcoal adsorption tends to saturation. The test area is the area where the first equilibrium state appears in the trend graph). Transfer the latex paint sample in the test area to a clean air chamber (formaldehyde concentration < 0.01 mg / m3), and monitor the formaldehyde release concentration within 24 hours. The release concentration is lower than 0.1 mg / m 3 is regarded as qualified, and the test results are shown in Table 2.

[0053] Table 2 Formaldehyde Desorption Test Results Is it qualified? qualified qualified qualified qualified qualified Unqualified Unqualified Unqualified Unqualified Unqualified Unqualified Unqualified Unqualified Unqualified qualified qualified This application can effectively prevent the secondary release of formaldehyde from bamboo charcoal latex paint. Not adding LDH or not performing multi-stage calcination will affect the stability of the entire adsorption system, and thus will affect the secondary adsorption ability of formaldehyde.

[0054] Test Example 3 Detect the moisture adsorption properties of the modified bamboo charcoal powder in Test Examples 1-5 and Comparative Examples 1 and 9. The bamboo charcoal powder in Comparative Example 1 is unmodified bamboo charcoal powder. The detection method is to place a sample (0.5 g) of the modified bamboo charcoal powder (bamboo charcoal powder) in a constant humidity chamber (relative humidity 90%, 25 °C). After 24 hours, measure the moisture adsorption amount (%) = (weight after adsorption - initial weight) / initial weight × 100%. The results are shown in Table 3.

[0055] Table 3 Moisture Adsorption Test Results Test Example 4 Detect the basic properties of the latex paints prepared in Test Examples 1-5 and Comparative Examples 1 and 2. According to the environmental protection safety standard GB 18582-2020, the physical property standard GB / T 9756-2018 (for interior walls), and GB / T 9286-1998 (adhesion), the test results are shown in Table 4. The detection methods involved are all prior art.

[0056] Table 4 Basic Property Test Results of Latex Paint

[0057] The latex paint prepared by the present invention meets the usage standards and has good properties such as resistance to scouring.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A bamboo charcoal purifying multifunctional interior wall latex paint, characterized in that: The product comprises the following components in parts by weight: 200 parts vinyl emulsion, 40-45 parts modified bamboo charcoal powder, 8-10 parts dispersant, 120-130 parts nanofiller, 80-90 parts deionized water and other additives. The modified bamboo charcoal powder was prepared by the following method: S1.

1. Disperse bamboo powder in deionized water, add magnesium nitrate, aluminum nitrate and urea in sequence, and stir to form a uniform suspension; transfer the suspension to a high-pressure reactor and react at 110℃ for 9 hours. After the reaction, cool, wash and dry to obtain LDH / bamboo fiber composite; immerse the LDH / bamboo fiber composite in a methanol solution of zinc nitrate hexahydrate, filter after soaking for 24 hours, and then add it to a methanol solution of 2-methylimidazole. Stir evenly and react for 12 hours. After the reaction, wash and dry to obtain ZIF-8@LDH / bamboo fiber composite. S1.2, Multi-stage calcination of ZIF-8@LDH / bamboo fiber composite: First stage of calcination: ZIF-8@LDH / bamboo fiber composite was heated from 25℃ to 250℃ in a tube furnace under nitrogen atmosphere at a heating rate of 2℃ / min, and held at 250℃ for 1 hour. Second stage calcination: Under nitrogen atmosphere, the temperature is increased from 250℃ to 600℃ at a rate of 5℃ / min, and held at 600℃ for 2 hours; Third stage of calcination: Subsequently, at 600℃, the atmosphere was switched to a nitrogen atmosphere containing 3% water vapor by volume, and the temperature was maintained for 30 minutes. Fourth stage calcination: Finally, the gas atmosphere was switched to inert gas argon, and the system was cooled from 600℃ to 150℃. Hexamethyldisilazane vapor was introduced at 150℃ and reacted for 1 hour to obtain the calcined composite. S1.3 After the calcined composite is cooled to room temperature, it is pulverized to obtain modified bamboo charcoal powder.

2. The bamboo charcoal purifying multifunctional interior wall latex paint according to claim 1, characterized in that: The mass ratio of magnesium nitrate, aluminum nitrate, and urea is 6:3:

5.

3. The bamboo charcoal purifying multifunctional interior wall latex paint according to claim 1, characterized in that: The mass ratio of zinc nitrate hexahydrate to 2-methylimidazole is 10:

13.

4. The bamboo charcoal purifying multifunctional interior wall latex paint according to claim 1, characterized in that: The dispersant comprises polycarboxylate dispersant DS707 and isomeric tridecyl alcohol polyoxyethylene ether in a mass ratio of 6:

1.

5. The bamboo charcoal purifying multifunctional interior wall latex paint according to claim 1, characterized in that: The nanofillers include nano-sized calcined kaolin, stearic acid-modified nano-calcium carbonate, nano-titanium dioxide, and nano-silica. The mass ratio of nano-calcined kaolin, stearic acid-modified nano-calcium carbonate, nano-titanium dioxide, and nano-silica is 1:2:2:

1.

6. The bamboo charcoal purifying multifunctional interior wall latex paint according to claim 1, characterized in that: The other additives include 8-10 parts thickener, 3-5 parts film-forming aid, and 1-3 parts defoamer; wherein the thickener includes at least one of polyurethane associative thickener, hydroxyethyl cellulose, and acrylate thickener; the film-forming aid is dodecyl alcohol ester; and the defoamer is defoamer DF7010.

7. A method for preparing a bamboo charcoal purifying multifunctional interior wall latex paint according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Prepare modified bamboo charcoal powder for later use; S2. Under low-speed stirring, dispersant and nanofiller are added sequentially to deionized water. After the addition is completed, the mixture is dispersed at high speed to obtain a primary slurry. S3. While stirring, vinyl emulsion, modified bamboo charcoal powder and other additives are added to the primary slurry in sequence. After continuous stirring until uniform, bamboo charcoal purification multifunctional interior wall latex paint is obtained; wherein, the vinyl emulsion is vinyl acetate-ethylene copolymer emulsion.

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