Scratch-resistant high-performance wall paint and preparation method thereof

Abstract

The application discloses a scratch-resistant high-performance wall paint and a preparation method thereof, and belongs to the technical field of functional materials. Methyl methacrylate, methacrylic acid, ZIF8-core-shell montmorillonite and polymethyl methacrylate-b-4-vinylpyridine are used as reaction monomers, and the obtained product is polymerized under the initiation of ammonium persulfate. The polymethyl methacrylate-b-4-vinylpyridine is an amphiphilic block polymer, wherein the polymethyl methacrylate is a hydrophobic end, and the hydrophobic end can significantly improve the compatibility with the ZIF8-core-shell montmorillonite. The vinyl group in the vinylpyridine at the other end can be used as an initiation site to polymerize with the ZIF8-core-shell montmorillonite, so that the ZIF8-core-shell montmorillonite as a reinforcing phase is fixed in the polymerization network and is not prone to agglomeration.

Description

Technical Field

[0001] This invention belongs to the field of functional materials technology, specifically a scratch-resistant high-performance wall paint and its preparation method. Background Technology

[0002] Environmentally friendly water-based ultra-wear-resistant topcoat is a water-based coating that is ultra-wear-resistant, high-hardness, scratch-resistant, and acid and alkali-resistant. It is widely used for floor protection in underground garages, industrial plants, schools, libraries, offices, and other places. Existing ultra-wear-resistant topcoats are mostly oil-based products, with relatively high VOCs, causing some air pollution, and have short application times, requiring completion within a short period. Therefore, there is a need to develop an environmentally friendly water-based ultra-wear-resistant coating with advantages such as low VOCs, ultra-wear resistance, high hardness, scratch resistance, long service life, water resistance, chemical resistance, and good anti-slip properties.

[0003] Chinese patent announcement CN113045954B discloses an environmentally friendly water-based ultra-wear-resistant topcoat and its preparation method. In this method, hydrophilic nano-silica and nano-alumina are added as reinforcing phases to improve the wear resistance and strength of the topcoat. However, the nano-size effect of hydrophilic nano-silica and nano-alumina makes them difficult to disperse in the topcoat system, resulting in agglomeration. Summary of the Invention

[0004] The purpose of this invention is to provide a scratch-resistant high-performance wall paint and its preparation method. The paint is obtained by polymerizing methyl methacrylate, methacrylic acid, ZIF8-core-shell montmorillonite, and polymethyl methacrylate-b-4-vinylpyridine as monomers under ammonium persulfate initiation. Polymethyl methacrylate-b-4-vinylpyridine is an amphiphilic block polymer, with methyl methacrylate as the hydrophobic end. This hydrophobic end significantly improves compatibility with ZIF8-core-shell montmorillonite. The vinyl group in the vinylpyridine at the other end can act as an initiation site to polymerize with ZIF8-core-shell montmorillonite, thus fixing the ZIF8-core-shell montmorillonite, as a reinforcing phase, within the polymer network, preventing agglomeration.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A method for preparing a scratch-resistant high-performance wall paint includes the following steps:

[0007] Step 1: Activate montmorillonite under hydrothermal conditions, and then modify it by intercalation using hexadecyltrimethylammonium bromide to obtain modified montmorillonite; using γ-(methacryloyloxy)propyltrimethoxysilane as a bridge, graft functional groups containing double bonds onto the surface of modified montmorillonite through silane hydrolysis and condensation reaction under acidic conditions to obtain double-bonded montmorillonite.

[0008] Step 2: Using montmorillonite as a carrier, ZIF-8 is synthesized on the surface and between layers of montmorillonite through a hydrothermal coordination reaction between cobalt metal ions and the organic ligand 2-methylimidazole, forming ZIF8-core-shell montmorillonite; using methyl methacrylate, methacrylic acid, ZIF8-core-shell montmorillonite and polymethyl methacrylate-b-4-vinylpyridine as monomers, they are polymerized under ammonium persulfate initiation to obtain a scratch-resistant polymer.

[0009] Step 3: Stir deionized water, BYK190, defoamer TEGO901W, scratch-resistant polymer, titanium dioxide, quartz powder, fatty amine modified waterborne epoxy curing agent, polyurethane modified epoxy resin and waterborne colorant at 1000-1200r / min for 10-15min until uniformly mixed to obtain scratch-resistant high-performance wall paint.

[0010] Furthermore, the dosage ratio of deionized water, BYK190, defoamer TEGO901W, scratch-resistant polymer, titanium dioxide, quartz powder, fatty amine modified waterborne epoxy curing agent, polyurethane modified epoxy resin, and waterborne color paste is 40-50g: 0.5-0.6g: 0.5-0.6g: 10-12g: 5-6g: 5-7g: 30-40g: 50-60g: 2-3g.

[0011] Furthermore, the specific preparation steps for modified montmorillonite are as follows:

[0012] Hydrothermal montmorillonite, hexadecyltrimethylammonium bromide, and methanol were added to a polytetrafluoroethylene hydrothermal reactor and stirred at 100-110℃ and 500-600 r / min for 24-26 h. After naturally cooling to room temperature, the mixture was centrifuged at 10000-11000 r / min for 3-4 min, filtered, and the filter cake was washed 2-4 times with methanol and deionized water. The cake was then vacuum dried at 60-80℃ for 1-2 h to obtain modified montmorillonite.

[0013] Furthermore, the ratio of hydrothermal montmorillonite, hexadecyltrimethylammonium bromide, and methanol is 37-39 g: 3-4 g: 500-600 mL.

[0014] Furthermore, the specific preparation steps of hydrothermal montmorillonite are as follows:

[0015] Montmorillonite and methanol were added to a polytetrafluoroethylene hydrothermal reactor at a ratio of 50-60g:500-600mL. The reactor was hydrothermally reacted at 100-110℃ and 500r / min for 24h. After filtration, the filter cake was washed 2-4 times with anhydrous ethanol and deionized water and dried under vacuum at 60-80℃ for 1-2h to obtain hydrothermal montmorillonite.

[0016] Furthermore, the specific preparation steps for double-bonded montmorillonite are as follows:

[0017] Modified montmorillonite, anhydrous ethanol, and deionized water were added to a reaction vessel and stirred for 10-12 min at 50-60℃ and 500-600 r / min. Then, γ-(methacryloyloxy)propyltrimethoxysilane was added, and the pH was adjusted to 3-4 with hydrochloric acid solution. The reaction was continued with stirring for 6-7 h. After filtration, the precipitate was washed 2-4 times with deionized water and anhydrous ethanol and dried under vacuum at 60-70℃ for 1-2 h to obtain double-bonded montmorillonite.

[0018] Furthermore, the ratio of modified montmorillonite, anhydrous ethanol, deionized water, and γ-(methacryloyloxy)propyltrimethoxysilane is 20-30g: 250-300mL: 100-150mL: 6-7g.

[0019] Furthermore, the specific preparation steps of ZIF8-core-shell montmorillonite are as follows:

[0020] Double-bonded montmorillonite, 2-methylimidazole, and deionized water were added to a reaction vessel. Sodium hexadecyl sulfate was dissolved in a 50-60 wt% ethanol solution and then added to the reaction vessel. The mixture was stirred at 100-110℃ and 400-500 r / min for 1-2 h. Then, cobalt nitrate hexahydrate was added, and the reaction was continued with stirring for 24-26 h. The mixture was then filtered, and the filter cake was washed 2-4 times with deionized water and anhydrous ethanol, respectively. The cake was then vacuum dried at 60-80℃ for 1-2 h to obtain ZIF8-core-shell montmorillonite.

[0021] Furthermore, the ratio of double-bonded montmorillonite, 2-methylimidazole, deionized water, sodium hexadecyl sulfate, ethanol solution, and cobalt nitrate hexahydrate is 15-20g: 20-25g: 800-900mL: 2-3g: 120-140mL: 10-11g.

[0022] Furthermore, the specific preparation steps of the scratch-resistant polymer are as follows:

[0023] Methyl methacrylate, polymethyl methacrylate-b-4-vinylpyridine, methacrylic acid, ZIF8-core-shell montmorillonite, and deionized water were added to a reaction vessel and stirred for 30-40 minutes at 20-25°C and 500-600 r / min. Then, sodium dodecyl sulfate and ammonium persulfate were added, and the mixture was heated to 80-90°C and reacted for 1-2 hours. The mixture was filtered, and the precipitate was washed 2-4 times with deionized water and anhydrous ethanol. The precipitate was then vacuum dried at 60-70°C for 1-2 hours to obtain a scratch-resistant polymer.

[0024] Furthermore, the ratio of methyl methacrylate, polymethyl methacrylate-b-4-vinylpyridine, methacrylic acid, ZIF8-core-shell montmorillonite, deionized water, sodium dodecyl sulfate, and ammonium persulfate is 15-20g:17-19g:16-17g:5-7g:250-300mL:3-4g:1-2g.

[0025] The beneficial effects of this invention are:

[0026] 1. The scratch-resistant polymer prepared in this invention is obtained by polymerization of methyl methacrylate, methacrylic acid, ZIF8-core-shell montmorillonite, and polymethyl methacrylate-b-4-vinylpyridine as monomers under ammonium persulfate initiation. Polymethyl methacrylate-b-4-vinylpyridine is an amphiphilic block polymer, wherein polymethyl methacrylate is the hydrophobic end, which can significantly improve the compatibility with ZIF8-core-shell montmorillonite. The vinyl group in the vinylpyridine at the other end can act as an initiation site to polymerize with ZIF8-core-shell montmorillonite, so that ZIF8-core-shell montmorillonite, as the reinforcing phase, is fixed in the polymer network and is not easy to agglomerate.

[0027] 2. This invention significantly improves the specific surface area and interlayer spacing by hydrothermally exfoliating the layers of modified montmorillonite, thereby increasing the number of active sites on the surface. A ZIF-8 structure is then hydrothermally synthesized on the modified montmorillonite surface using the modified montmorillonite as a carrier. The ZIF-8 structure exhibits excellent photocatalytic activity and has a three-dimensional polyhedral shape, allowing it to adhere to the surface and interlayer spaces of the modified montmorillonite. This improves both the roughness and wear resistance of the modified montmorillonite and its mechanical strength. By generating relative slip and dispersing stress, it further enhances the impact resistance of the topcoat.

[0028] 3. In the scratch-resistant polymer prepared by this invention, the pyridine group can act as a strong ligand for transition metal ions. As a Lewis base group, it readily forms coordination bonds with cobalt metal ions in ZIF8-core-shell montmorillonite. The doping and coordination of the pyridine group can promote the formation of active sites and improve photocatalytic activity. The pyridine group can endow the scratch-resistant high-performance wall paint with a certain acid response. In an acidic environment, the N atom on the pyridine group has a lone pair of electrons, which can act as a proton donor to protonate the pyridine group and make it positively charged under acidic conditions. Meanwhile, the montmorillonite sheets themselves are negatively charged and have excellent acid and alkali resistance. Under the synergistic effect of the two, when the wall paint is eroded by acidic substances, it can not only resist corrosion but also improve its mechanical strength. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1: A method for preparing a scratch-resistant high-performance wall paint, comprising the following steps:

[0031] S1: Add 50g of montmorillonite and 500mL of methanol to a polytetrafluoroethylene hydrothermal reactor and hydrothermally react at 100℃ and 500r / min for 24h. Filter the mixture, wash the filter cake twice with anhydrous ethanol and deionized water, and dry it under vacuum at 60℃ for 1h to obtain hydrothermal montmorillonite. Add 37g of hydrothermal montmorillonite, 3g of hexadecyltrimethylammonium bromide and 500mL of methanol to a polytetrafluoroethylene hydrothermal reactor and stir at 100℃ and 500r / min for 24h. Allow it to cool naturally to room temperature, centrifuge at 10000r / min for 3min, filter the mixture, wash the filter cake twice with methanol and deionized water, and dry it under vacuum at 60℃ for 1h to obtain modified montmorillonite.

[0032] S2: Add 20g of modified montmorillonite, 250mL of anhydrous ethanol and 100mL of deionized water to a reaction vessel, stir for 10min at 50℃ and 500r / min, then add 6g of γ-(methacryloyloxy)propyltrimethoxysilane, adjust the pH to 3 with hydrochloric acid solution, continue stirring for 6h, filter, wash the precipitate twice with deionized water and anhydrous ethanol, and dry under vacuum at 60℃ for 1h to obtain double-bonded montmorillonite.

[0033] S3: Add 15g of double-bonded montmorillonite, 20g of 2-methylimidazole and 800mL of deionized water to the reaction vessel. Dissolve 2g of sodium hexadecyl sulfate in 120mL of 50wt% ethanol solution and add it to the reaction vessel. Stir at 100℃ and 400r / min for 1h. Then add 10g of cobalt nitrate hexahydrate and continue stirring for 24h. Filter the mixture and wash the filter cake twice with deionized water and anhydrous ethanol, respectively. Dry it under vacuum at 60℃ for 1h to obtain ZIF8-core-shell montmorillonite.

[0034] S4: Add 15g of methyl methacrylate, 17g of polymethyl methacrylate-b-4-vinylpyridine, 16g of methacrylic acid, 5g of ZIF8-core-shell montmorillonite and 250mL of deionized water to a reaction vessel, stir for 30min at 20℃ and 500r / min, then add 3g of sodium dodecyl sulfate and 1g of ammonium persulfate, heat to 80℃, continue to react for 1h, filter, wash the precipitate twice with deionized water and anhydrous ethanol, and vacuum dry at 60℃ for 1h to obtain a scratch-resistant polymer.

[0035] S5: Mix 40g deionized water, 0.5g BYK190, 0.5g defoamer TEGO901W, 10g scratch-resistant polymer, 5g titanium dioxide, 5g quartz powder, 30g fatty amine modified waterborne epoxy curing agent, 50g polyurethane modified epoxy resin and 2g waterborne colorant at 1000r / min for 10min until uniformly mixed to obtain scratch-resistant high-performance wall paint.

[0036] Example 2: A method for preparing a scratch-resistant high-performance wall paint, comprising the following steps:

[0037] S1: Add 55g of montmorillonite and 550mL of methanol to a polytetrafluoroethylene hydrothermal reactor and hydrothermally react at 105℃ and 500r / min for 24h. Filter the mixture, wash the filter cake three times with anhydrous ethanol and deionized water, and vacuum dry at 70℃ for 1.5h to obtain hydrothermal montmorillonite. Add 38g of hydrothermal montmorillonite, 3.5g of cetyltrimethylammonium bromide and 550mL of methanol to a polytetrafluoroethylene hydrothermal reactor and stir at 105℃ and 550r / min for 25h. Allow the mixture to cool naturally to room temperature, centrifuge at 10500r / min for 3.5min, filter the mixture, wash the filter cake three times with methanol and deionized water, and vacuum dry at 70℃ for 1.5h to obtain modified montmorillonite.

[0038] S2: Add 25g of modified montmorillonite, 275mL of anhydrous ethanol and 125mL of deionized water to a reaction vessel, stir for 11min at 55℃ and 550r / min, then add 6.5g of γ-(methacryloyloxy)propyltrimethoxysilane, adjust the pH to 3.5 with hydrochloric acid solution, continue stirring for 6.5h, filter, wash the precipitate three times with deionized water and anhydrous ethanol, and dry under vacuum at 65℃ for 1.5h to obtain double-bonded montmorillonite.

[0039] S3: 17.5g of double-bonded montmorillonite, 22.5g of 2-methylimidazole and 850mL of deionized water were added to the reaction vessel. 2.5g of sodium hexadecyl sulfate was dissolved in 130mL of 55wt% ethanol solution and then added to the reaction vessel. The mixture was stirred at 105℃ and 450r / min for 1.5h. Then 10.5g of cobalt nitrate hexahydrate was added, and the reaction was continued to be stirred for 25h. The mixture was filtered, and the filter cake was washed three times with deionized water and three times with anhydrous ethanol. The cake was then dried under vacuum at 70℃ for 1.5h to obtain ZIF8-core-shell montmorillonite.

[0040] S4: 17.5g of methyl methacrylate, 18g of polymethyl methacrylate-b-4-vinylpyridine, 16.5g of methacrylic acid, 6g of ZIF8-core-shell montmorillonite, and 275mL of deionized water were added to a reaction vessel and stirred at 22.5℃ and 550r / min for 35min. Then, 3.5g of sodium dodecyl sulfate and 1.5g of ammonium persulfate were added, and the mixture was heated to 85℃ and reacted for another 1.5h. The mixture was filtered, and the precipitate was washed three times with deionized water and anhydrous ethanol. The precipitate was then dried under vacuum at 65℃ for 1.5h to obtain a scratch-resistant polymer.

[0041] S5: Mix 45g deionized water, 0.55g BYK190, 0.55g defoamer TEGO901W, 11g scratch-resistant polymer, 5.5g titanium dioxide, 6g quartz powder, 35g fatty amine modified waterborne epoxy curing agent, 55g polyurethane modified epoxy resin and 2.5g waterborne colorant at 1100r / min for 12.5min until uniformly mixed to obtain scratch-resistant high-performance wall paint.

[0042] Example 3: A method for preparing a scratch-resistant high-performance wall paint, comprising the following steps:

[0043] S1: Add 60g of montmorillonite and 600mL of methanol to a polytetrafluoroethylene hydrothermal reactor and hydrothermally react at 110℃ and 500r / min for 24h. Filter the mixture, wash the filter cake four times with anhydrous ethanol and deionized water, and dry it under vacuum at 80℃ for 2h to obtain hydrothermal montmorillonite. Add 39g of hydrothermal montmorillonite, 4g of hexadecyltrimethylammonium bromide and 600mL of methanol to a polytetrafluoroethylene hydrothermal reactor and stir at 110℃ and 600r / min for 26h. Allow the mixture to cool naturally to room temperature, centrifuge at 11000r / min for 4min, filter the mixture, wash the filter cake four times with methanol and deionized water, and dry it under vacuum at 80℃ for 2h to obtain modified montmorillonite.

[0044] S2: Add 30g of modified montmorillonite, 300mL of anhydrous ethanol and 150mL of deionized water to a reaction vessel, stir for 12min at 60℃ and 600r / min, then add 7g of γ-(methacryloyloxy)propyltrimethoxysilane, adjust the pH to 4 with hydrochloric acid solution, continue stirring for 7h, filter, wash the precipitate 4 times with deionized water and anhydrous ethanol, and vacuum dry at 70℃ for 2h to obtain double-bonded montmorillonite.

[0045] S3: Add 20g of double-bonded montmorillonite, 25g of 2-methylimidazole and 900mL of deionized water to a reaction vessel. Dissolve 3g of sodium hexadecyl sulfate in 140mL of 60wt% ethanol solution and add it to the reaction vessel. Stir at 110℃ and 500r / min for 2h. Then add 11g of cobalt nitrate hexahydrate and continue stirring for 26h. Filter the mixture and wash the filter cake four times with deionized water and anhydrous ethanol, respectively. Dry the mixture under vacuum at 80℃ for 2h to obtain ZIF8-core-shell montmorillonite.

[0046] S4: Add 20g of methyl methacrylate, 19g of polymethyl methacrylate-b-4-vinylpyridine, 17g of methacrylic acid, 7g of ZIF8-core-shell montmorillonite and 300mL of deionized water to a reaction vessel, stir for 40min at 25℃ and 600r / min, then add 4g of sodium dodecyl sulfate and 2g of ammonium persulfate, heat to 90℃ and continue the reaction for 2h, filter, wash the precipitate 4 times with deionized water and anhydrous ethanol, and vacuum dry at 70℃ for 2h to obtain a scratch-resistant polymer.

[0047] S5: Mix 50g deionized water, 0.6g BYK190, 0.6g defoamer TEGO901W, 12g scratch-resistant polymer, 6g titanium dioxide, 7g quartz powder, 40g fatty amine modified waterborne epoxy curing agent, 60g polyurethane modified epoxy resin and 3g waterborne colorant at 1200r / min for 15min until uniformly mixed to obtain scratch-resistant high-performance wall paint.

[0048] Comparative Example 1: Based on Example 3, the modified montmorillonite in step S2 was replaced with the raw montmorillonite in step S1.

[0049] Comparative Example 2: Based on Example 3, the double-bonded montmorillonite in step S3 was replaced with the modified montmorillonite in step S1.

[0050] Comparative Example 3: Based on Example 3, the ZIF8-core-shell montmorillonite in step S4 was replaced with the double-bonded montmorillonite in step S2.

[0051] The scratch-resistant high-performance wall paints prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests.

[0052] 1. Alkali resistance test: Refer to the standard test of GB / T 9265 "Determination of alkali resistance of architectural coatings" and the acid resistance test of GB / T 23988 "Determination of acid and alkali resistance of coatings". Immerse the sample in the acid or alkali solution of the specified concentration for 24 hours. After washing, observe whether the coating shows any abnormalities such as discoloration, peeling, or softening.

[0053] 2. Abrasion resistance test: Refer to the TABER abrasion tester and GB / T 1768 "Determination of abrasion resistance of paints and varnishes - Rotating rubber wheel method" or ASTM D1044: Under a load of 750g, the coating is rubbed by a specified grinding wheel at a rotational speed of 500r / min, and the mass loss before and after the test is recorded.

[0054] 3. Refer to GB / T 6739 "Determination of Hardness of Paints and Varnishes by Pencil Method": Use a pencil with a hardness of 4H to scratch the coating surface at a specified angle and load, and observe whether scratches that penetrate the coating are produced.

[0055] 4. According to the standard test of GB / T 21353 "Determination of anti-slip properties of floor coatings": use a friction coefficient tester to test the dynamic / static friction coefficients of the coating surface under dry conditions.

[0056] 5. Refer to the standard test of GB / T 9279 "Paints and Varnishes - Scratch Test": Use a scratch tester to scratch the coating surface with a specified load and scratch speed. Observe the depth and width of the scratch and the damage to the coating by visual inspection or microscopy, and determine the good grade.

[0057] 6. Aging resistance test: Referring to GB / T 14522-2008 standard, the ultraviolet radiation in sunlight was simulated by the radiation of fluorescent ultraviolet lamp UVB-313. The scratch-resistant high-performance wall paint was exposed to periodic repeated light and humidity environment for 4000h. After the test, the tested samples were rated according to GB / T 1766-2008 standard.

[0058] The results are shown in Table 1:

[0059] Table 1

[0060]

[0061] As shown in Table 1, in Comparative Example 1, the modified montmorillonite in step S2 was replaced with the raw montmorillonite in step S1. The original montmorillonite had a dense interlayer structure, small specific surface area, and no hydrophobic organic group modification. It had extremely poor compatibility with ZIF-8 and the polymer system, which led to ZIF-8 agglomeration and inability to be uniformly loaded on the surface and interlayer of montmorillonite, resulting in complete failure of the reinforcing phase interaction. The lack of active sites brought by hydrothermal activation resulted in extremely low efficiency of subsequent double bond grafting. Montmorillonite could not form a stable bond with the polymer network, the internal structure of the coating was loose, and the synergistic acid resistance of pyridine groups and montmorillonite sheets was missing. The surface was prone to loss of gloss in acidic environments, and the acid resistance was significantly reduced. At the same time, the agglomeration of ZIF-8 led to insufficient photocatalytic activity.

[0062] In Comparative Example 2, the double-bonded montmorillonite in step S3 was replaced with the modified montmorillonite in step S1. ZIF-8 showed poor loading stability, uneven dispersion, and failure of mechanical reinforcement effect. Modified montmorillonite lacked double-bonded active sites and could not participate in subsequent polymerization reactions. It was only dispersed in the polymer as a physical filler, with poor compatibility with the polymer matrix and weak interfacial bonding. The presence of double bonds could assist cobalt ions of ZIF-8 in forming coordination bonds with pyridine groups in the polymer, promoting the generation of active sites and enhancing the photocatalytic effect of ZIF-8. Pyridine groups were difficult to form effective synergy with montmorillonite sheets.

[0063] Comparative Example 3 replaced the ZIF8-core-shell montmorillonite in step S4 with the double-bonded montmorillonite in step S2. Without the three-dimensional polyhedral structure of ZIF-8, it is impossible to improve wear resistance by roughening the surface or enhance impact resistance by dispersing stress through slip. Although the double-bonded montmorillonite can provide some support, it lacks the photocatalytic active center of ZIF-8 and has no coordination effect between cobalt ions and pyridine groups, so it cannot promote the generation of active sites. Its resistance to ultraviolet aging is significantly reduced, and it lacks the mechanical enhancement effect brought by ZIF-8, resulting in insufficient scratch resistance.

[0064] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A method for preparing a scratch-resistant high-performance wall paint, characterized in that, Includes the following steps: Step 1: Activate montmorillonite under hydrothermal conditions, and then modify it by intercalation using hexadecyltrimethylammonium bromide to obtain modified montmorillonite; using γ-(methacryloyloxy)propyltrimethoxysilane as a bridge, graft functional groups containing double bonds onto the surface of modified montmorillonite through silane hydrolysis and condensation reaction under acidic conditions to obtain double-bonded montmorillonite. Step 2: Using montmorillonite as a carrier, ZIF-8 is synthesized on the surface and between layers of montmorillonite through a hydrothermal coordination reaction between cobalt metal ions and the organic ligand 2-methylimidazolium, forming ZIF8-core-shell montmorillonite; using methyl methacrylate, methacrylic acid, ZIF8-core-shell montmorillonite and polymethyl methacrylate-b-4-vinylpyridine as monomers, polymerization is carried out under the initiation of ammonium persulfate to obtain a scratch-resistant polymer. Step 3: Stir deionized water, BYK190, TEGO901W, scratch-resistant polymer, titanium dioxide, quartz powder, fatty amine modified waterborne epoxy curing agent, polyurethane modified epoxy resin and waterborne colorant at 1000-1200r / min for 10-15min until they are evenly mixed to obtain scratch-resistant high-performance wall paint. The ratio of deionized water, BYK190, defoamer TEGO901W, scratch-resistant polymer, titanium dioxide, quartz powder, fatty amine modified waterborne epoxy curing agent, polyurethane modified epoxy resin, and waterborne color paste is 40-50g: 0.5-0.6g: 0.5-0.6g: 10-12g: 5-6g: 5-7g: 30-40g: 50-60g: 2-3g; The specific preparation steps of the scratch-resistant polymer are as follows: Methyl methacrylate, polymethyl methacrylate-b-4-vinylpyridine, methacrylic acid, ZIF8-core-shell montmorillonite, and deionized water were added to a reaction vessel and stirred for 30-40 minutes at 20-25°C and 500-600 r / min. Then, sodium dodecyl sulfate and ammonium persulfate were added, and the mixture was heated to 80-90°C and reacted for 1-2 hours. The mixture was filtered, and the precipitate was washed 2-4 times with deionized water and anhydrous ethanol. The precipitate was then vacuum dried at 60-70°C for 1-2 hours to obtain a scratch-resistant polymer.

2. The method for preparing a scratch-resistant high-performance wall paint according to claim 1, characterized in that, The specific preparation steps of the modified montmorillonite are as follows: Hydrothermal montmorillonite, hexadecyltrimethylammonium bromide, and methanol were added to a polytetrafluoroethylene hydrothermal reactor and stirred at 100-110℃ and 500-600 r / min for 24-26 h. After naturally cooling to room temperature, the mixture was centrifuged at 10000-11000 r / min for 3-4 min, filtered, and the filter cake was washed 2-4 times with methanol and deionized water. The cake was then vacuum dried at 60-80℃ for 1-2 h to obtain modified montmorillonite. The ratio of hydrothermal montmorillonite, hexadecyltrimethylammonium bromide, and methanol is 37-39g: 3-4g: 500-600mL.

3. The method for preparing a scratch-resistant high-performance wall paint according to claim 2, characterized in that, The specific preparation steps of the hydrothermal montmorillonite are as follows: Montmorillonite and methanol were added to a polytetrafluoroethylene hydrothermal reactor at a ratio of 50-60g:500-600mL. The reactor was hydrothermally reacted at 100-110℃ and 500r / min for 24h. After filtration, the filter cake was washed 2-4 times with anhydrous ethanol and deionized water and dried under vacuum at 60-80℃ for 1-2h to obtain hydrothermal montmorillonite.

4. The method for preparing a scratch-resistant high-performance wall paint according to claim 1, characterized in that, The specific preparation steps for the double-bonded montmorillonite are as follows: Modified montmorillonite, anhydrous ethanol, and deionized water were added to a reaction vessel and stirred for 10-12 min at 50-60℃ and 500-600 r / min. Then, γ-(methacryloyloxy)propyltrimethoxysilane was added, and the pH was adjusted to 3-4 with hydrochloric acid solution. The reaction was continued with stirring for 6-7 h. After filtration, the precipitate was washed 2-4 times with deionized water and anhydrous ethanol and dried under vacuum at 60-70℃ for 1-2 h to obtain double-bonded montmorillonite. The ratio of the modified montmorillonite, anhydrous ethanol, deionized water and γ-(methacryloyloxy)propyltrimethoxysilane is 20-30g: 250-300mL: 100-150mL: 6-7g.

5. The method for preparing a scratch-resistant high-performance wall paint according to claim 1, characterized in that, The specific preparation steps for ZIF8-core-shell montmorillonite are as follows: Double-bonded montmorillonite, 2-methylimidazole, and deionized water were added to a reaction vessel. Sodium hexadecyl sulfate was dissolved in a 50-60 wt% ethanol solution and then added to the reaction vessel. The mixture was stirred at 100-110℃ and 400-500 r / min for 1-2 h. Then, cobalt nitrate hexahydrate was added, and the reaction was continued with stirring for 24-26 h. The mixture was then filtered, and the filter cake was washed 2-4 times with deionized water and anhydrous ethanol, respectively. The cake was then vacuum dried at 60-80℃ for 1-2 h to obtain ZIF8-core-shell montmorillonite.

6. The method for preparing a scratch-resistant high-performance wall paint according to claim 5, characterized in that, The ratio of the amount of double-bonded montmorillonite, 2-methylimidazole, deionized water, sodium hexadecyl sulfate, ethanol solution and cobalt nitrate hexahydrate is 15-20g: 20-25g: 800-900mL: 2-3g: 120-140mL: 10-11g.

7. The method for preparing a scratch-resistant high-performance wall paint according to claim 1, characterized in that, The ratio of methyl methacrylate, polymethyl methacrylate-b-4-vinylpyridine, methacrylic acid, ZIF8-core-shell montmorillonite, deionized water, sodium dodecyl sulfate, and ammonium persulfate is 15-20g:17-19g:16-17g:5-7g:250-300mL:3-4g:1-2g.

8. A scratch-resistant, high-performance wall paint, characterized in that, It is prepared by the preparation method described in any one of claims 1-7.

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