A modified inorganic particle doped water-based paint and preparation method thereof

Abstract

The present invention relates to a modified inorganic particle doped water-based paint and a preparation method thereof, belonging to the technical field of water-based paint. The raw materials for preparing the water-based paint include, by weight, 35-50 parts of water-based acrylic resin, 5-10 parts of modified inorganic particles, 8-12 parts of polyvinyl alcohol, 0.1-0.5 parts of defoaming agent, and 0.1-0.5 parts of dispersant; the modified inorganic particles are obtained by mixing nano titanium dioxide flame retardant particles, organic acid and biomass and then subjecting them to hydrothermal treatment, and the nano titanium dioxide flame retardant particles are obtained by subjecting polyimide particles and nano titanium dioxide particles to thermal treatment. The modified inorganic particles proposed by the present invention have good dispersibility and strong interaction force with the water-based paint matrix. Nano titanium dioxide is used instead of nano alumina, applied to water-based paint, and the flame retardancy of the water-based paint is increased. Organic acid, biomass powder and nano titanium dioxide flame retardant particles are used for hydrothermal treatment to increase the antibacterial durability of the water-based paint.

Description

Technical Field

[0001] The invention belongs to the technical field of water-based paints, and in particular relates to a modified inorganic particle-doped water-based paint and a preparation method thereof. Background Art

[0002] Water-based paint refers to paint that uses water as a solvent or dispersion medium. Water-based paint is harmless to the human body and has little pollution to the environment. It is widely used in various anti-corrosion protection aspects such as automobiles, ships, machinery manufacturing, railways, bridges, boilers, steel structures, etc. Therefore, the antibacterial, anti-corrosion and flame retardant properties of water-based paint are particularly important.

[0003] CN202410579151.0 discloses a water-based paint containing nanomaterials and a preparation method thereof, wherein polyurethane and nano-alumina are modified, and the phosphorus element contained in the modified polyurethane and the modified nano-alumina has a good flame retardant effect, and the quaternary ammonium salt group contained in the modified nano-alumina has a synergistic antibacterial effect. However, the preparation process is slightly complicated, and the actual dispersion effect of the modified nano-alumina prepared therefrom in the water-based paint is not as good as expected, and agglomeration still occurs, affecting the performance of the water-based paint. Moreover, diethyl phosphite, the raw material for the preparation of modified nano-alumina, will decompose in hot water to produce toxic gases, which has a large safety hazard.

[0004] CN202410413931.8 discloses a water-based paint with self-cleaning function and a preparation method thereof, and CN202410854100.4 discloses a waterproof coating containing modified silicone rubber and a preparation method thereof, both of which use quaternary ammonium salt groups as antibacterial ingredients. CN202310572897.4 discloses an environmentally friendly water-based paint, which uses antibacterial and mildew-proof agents as antibacterial ingredients. However, the antibacterial effects of the above ingredients are not as durable as those of inorganic nanoparticles. Summary of the invention

[0005] The purpose of the present invention is to provide a modified inorganic particle doped water-based paint and a preparation method thereof in order to solve the above problems.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0007] The first object of the present invention is to provide a modified inorganic particle doped water-based paint, wherein the raw materials for preparing the water-based paint include, by weight, 35-50 parts of water-based acrylic resin, 5-10 parts of modified inorganic particles, 8-12 parts of polyvinyl alcohol, 0.1-0.5 parts of defoaming agent, and 0.1-0.5 parts of dispersant;

[0008] The modified inorganic particles are obtained by mixing nano titanium dioxide flame retardant particles, organic acid and biomass and subjecting them to hydrothermal treatment, and the nano titanium dioxide flame retardant particles are obtained by subjecting polyimide particles and nano titanium dioxide particles to heat treatment.

[0009] As a further improvement of the present invention, the solid content of the aqueous resin dispersion is 30-50wt%, and the aqueous resin dispersion is one or a combination of aqueous acrylic resin, aqueous epoxy resin, aqueous polyurethane, and aqueous silicone resin.

[0010] As a further improvement of the present invention, the preparation process of the nano titanium dioxide flame retardant particles is to immerse the polyimide particles in ammonium chloride with a concentration of 10-12wt%, dry them and mix them with nano titanium dioxide, and continuously perform carbonization and graphitization heat treatment on the mixture under a nitrogen atmosphere.

[0011] As a further improvement of the present invention, the carbonization treatment is to treat at a temperature of 900-950°C for 0.5-1h, and the graphitization treatment is to treat at a temperature of 1800-2000°C for 0.5-1h.

[0012] As a further improvement of the present invention, the mixing mass ratio of the polyimide particles and the nano-titanium dioxide is (1-3):1.

[0013] As a further improvement of the present invention, the preparation of the modified inorganic particles comprises the following steps:

[0014] The organic acid is dissolved in deionized water to obtain an organic acid solution, and then nano titanium dioxide flame retardant particles and biomass powder are dispersed in the organic acid solution, and then the pH is adjusted to 7-8 using sodium hydroxide, and then the solution is sealed in a reactor, heated to 220-230°C, and kept at a constant temperature for 12-48 hours. After cooling, the reactant is taken out, washed and dried, and the mass ratio of the organic acid, the nano titanium dioxide flame retardant particles and the biomass powder is (5-10):1:(5-10).

[0015] As a further improvement of the present invention, the organic acid is one of citric acid, acetic acid, fumaric acid or tartaric acid.

[0016] As a further improvement of the present invention, the raw material of the biomass powder is one of corn straw, rice husk, bamboo or soybean straw.

[0017] As a further improvement of the present invention, when preparing the modified inorganic particles, zinc oxide powder, nano titanium dioxide flame retardant particles and biomass powder are dispersed in an organic acid solution, and the amount of zinc oxide powder is 20-30% of the nano titanium dioxide flame retardant particles.

[0018] The second purpose of the present invention is to provide a method for preparing a water-based paint doped with modified inorganic particles, comprising adding 35-50 parts of a water-based acrylic resin, 5-10 parts of modified inorganic particles, 8-12 parts of polyvinyl alcohol, 0.1-0.5 parts of a defoaming agent, and 0.1-0.5 parts of a dispersant into a stirrer, stirring evenly at a stirring speed of 600-800 r / min and a stirring time of 10-15 min to obtain a water-based paint doped with modified inorganic particles.

[0019] The beneficial effects of the present invention are:

[0020] (1) The modified inorganic particles proposed in the present invention use nano titanium dioxide instead of nano aluminum oxide. Nano titanium dioxide can effectively increase the thermal decomposition temperature of the material and delay the thermal degradation process of the material. Compared with nano aluminum oxide, although it also has a flame retardant effect, its thermal conductivity is better than that of nano titanium dioxide. Moreover, nano titanium dioxide can be applied to water-based paint to significantly increase its glossiness. Under the same light conditions, its surface glossiness is 5-10% higher than that of nano aluminum oxide coating.

[0021] (2) The modified inorganic particles proposed in the present invention utilize polyimide particles instead of nano-titanium dioxide as a flame retardant component, and the flame retardancy of polyimide is enhanced by subjecting the polyimide particles and nano-titanium dioxide particles to high-temperature treatment, thereby reducing the amount of nano-titanium dioxide used. Application to water-based paint can further enhance the anti-aging properties of the water-based paint.

[0022] (3) The present invention adds modified inorganic particles to the water-based paint, and uses citric acid, rice husk powder and nano titanium dioxide flame retardant particles for hydrothermal treatment to promote the generation of carbon quantum dots and graphene quantum dots, thereby increasing the antibacterial durability of the water-based paint.

[0023] (4) The modified inorganic particles proposed in the present invention have good dispersibility and are not easy to agglomerate in water-based paints. The interaction between the nanoparticles and the water-based paint matrix is ​​strong, which enhances the adhesion and hardness of the coating. DETAILED DESCRIPTION

[0024] The present application is described in further detail below. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technicians in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0025] 1. Materials

[0026] The solid content of the aqueous resin dispersion used in the present invention is 30-50wt%, and the aqueous resin dispersion is one or a combination of aqueous acrylic resin, aqueous epoxy resin, aqueous polyurethane, and aqueous silicone resin. The aqueous acrylic resin used in the following examples was purchased from Zhangjiagang DIC Chemical Co., Ltd.

[0027] The polyimide particles of the present invention were purchased from Xuzhou Ruiyi New Materials Co., Ltd., and the nano titanium dioxide particles and zinc oxide were purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.

[0028] The organic acid used in the present invention is one of citric acid, acetic acid, fumaric acid or tartaric acid, and other carboxyl-containing acids may also be used. Citric acid is used in the following examples.

[0029] The raw material of the biomass powder used in the present invention is one of corn stalks, rice husks, bamboo or soybean stalks. The raw material is carbonized at 700°C ± 100°C to obtain rice husk charcoal, which is then crushed into biomass powder by a crusher. Rice husk powder is used in the following examples.

[0030] The defoamer used in the present invention is BYK polysiloxane defoamer, and the dispersant used is polyvinyl ether dispersant.

[0031] Unless otherwise specified, the methods used in the present invention are conventional methods known to those skilled in the art, and the reagents and other materials used are commercially available products unless otherwise specified.

[0032] 2. Methods

[0033] Example 1

[0034] The modified inorganic particles in this embodiment are doped with water-based paint, and the preparation process is as follows:

[0035] (1) The polyimide particles were immersed in ammonium chloride with a concentration of 12 wt%, dried at low temperature (200±50°C), and then mixed with nano-titanium dioxide particles in a mass ratio of 2:1. The mixture was placed in a vacuum carbonization furnace and continuously carbonized and graphitized under a nitrogen atmosphere. The carbonization treatment was performed at 920±10°C for 1 hour and the graphitization treatment was performed at 1900±10°C for 1 hour to obtain nano-titanium dioxide flame retardant particles.

[0036] (2) dissolving tartaric acid in deionized water to obtain a citric acid solution, and then dispersing nano titanium dioxide flame retardant particles and rice husk powder in the citric acid solution, wherein the mass ratio of citric acid, nano titanium dioxide flame retardant particles and rice husk powder is 10:1:10, and then adjusting the pH to between 7 and 8 using sodium hydroxide, and then sealing the solution in a reactor, heating it to 225±5°C, maintaining the temperature for 12 hours, cooling it, taking out the reactants, washing and drying them, and grinding them to obtain modified inorganic particles;

[0037] (3) Add 45 parts of water-based acrylic resin, 10 parts of modified inorganic particles, 8 parts of polyvinyl alcohol, 0.1 parts of defoaming agent, and 0.2 parts of dispersant into a stirrer and stir evenly at a stirring speed of 600 r / min for 15 min to obtain a water-based paint doped with modified inorganic particles.

[0038] Example 2

[0039] The modified inorganic particles in this embodiment are doped with water-based paint, and the preparation process is as follows:

[0040] (1) The polyimide particles were immersed in ammonium chloride with a concentration of 12 wt%, dried at low temperature (200±50°C), and then mixed with nano-titanium dioxide particles in a mass ratio of 2:1. The mixture was placed in a vacuum carbonization furnace and continuously carbonized and graphitized under a nitrogen atmosphere. The carbonization treatment was performed at 920±10°C for 1 hour and the graphitization treatment was performed at 1900±10°C for 1 hour to obtain nano-titanium dioxide flame retardant particles.

[0041] (2) Dissolving citric acid in deionized water to obtain a citric acid solution, and then dispersing nano titanium dioxide flame retardant particles and rice husk powder in the citric acid solution, wherein the mass ratio of citric acid, nano titanium dioxide flame retardant particles and rice husk powder is 8:1:8, and then adjusting the pH to between 7 and 8 using sodium hydroxide, and then sealing the solution in a reactor, heating it to 225±5°C, maintaining the temperature for 12 hours, cooling it, taking out the reactants, washing and drying them, and grinding them to obtain modified inorganic particles;

[0042] (3) Add 45 parts of water-based acrylic resin, 10 parts of modified inorganic particles, 10 parts of polyvinyl alcohol, 0.2 parts of defoaming agent, and 0.2 parts of dispersant into a stirrer and stir evenly at a stirring speed of 700 r / min for 10 min to obtain a water-based paint doped with modified inorganic particles.

[0043] Example 3

[0044] The modified inorganic particles in this embodiment are doped with water-based paint, and the preparation process is as follows:

[0045] (1) The polyimide particles are immersed in ammonium chloride with a concentration of 12 wt%, and then dried at low temperature (200±50°C) and mixed with nano-titanium dioxide particles in a mass ratio of 1:1. The mixture is placed in a vacuum carbonization furnace and continuously carbonized and graphitized in a nitrogen atmosphere. The carbonization treatment is performed at 920±10°C for 1 hour and the graphitization treatment is performed at 1900±10°C for 1 hour to obtain nano-titanium dioxide flame retardant particles;

[0046] (2) dissolving citric acid in deionized water to obtain a citric acid solution, and then dispersing nano titanium dioxide flame retardant particles and rice husk powder in the citric acid solution, wherein the mass ratio of citric acid, nano titanium dioxide flame retardant particles and rice husk powder is 8:1:8, and then adjusting the pH to 7-8 with sodium hydroxide, and then sealing the solution in a reactor, heating to 225±5°C, maintaining the temperature for 12 hours, cooling, taking out the reactants, washing and drying, and grinding to obtain modified inorganic particles;

[0047] (3) Add 40 parts of water-based acrylic resin, 10 parts of modified inorganic particles, 8 parts of polyvinyl alcohol, 0.1 parts of defoaming agent, and 0.2 parts of dispersant into a stirrer and stir evenly at a stirring speed of 700 r / min for 10 min to obtain a water-based paint doped with modified inorganic particles.

[0048] Example 4

[0049] The modified inorganic particles in this embodiment are doped with water-based paint, and the preparation process is as follows:

[0050] (1) The polyimide particles are immersed in ammonium chloride with a concentration of 12 wt%, and then dried at low temperature (200±50°C) and mixed with nano-titanium dioxide particles in a mass ratio of 1:1. The mixture is placed in a vacuum carbonization furnace and continuously carbonized and graphitized in a nitrogen atmosphere. The carbonization treatment is performed at 920±10°C for 1 hour and the graphitization treatment is performed at 1900±10°C for 1 hour to obtain nano-titanium dioxide flame retardant particles;

[0051] (2) Dissolving citric acid in deionized water to obtain a citric acid solution, and then dispersing nano titanium dioxide flame retardant particles, zinc oxide powder and rice husk powder in the citric acid solution, wherein the mass ratio of citric acid, nano titanium dioxide flame retardant particles and rice husk powder is 8:0.8:0.2:8, and then adjusting the pH to between 7 and 8 using sodium hydroxide, and then sealing the solution in a reactor, heating it to 225±5°C, maintaining the temperature for 12 hours, cooling it, taking out the reactants, washing and drying them, and grinding them to obtain modified inorganic particles;

[0052] (3) Add 40 parts of water-based acrylic resin, 10 parts of modified inorganic particles, 10 parts of polyvinyl alcohol, 0.1 parts of defoaming agent, and 0.1 parts of dispersant into a stirrer and stir evenly at a stirring speed of 800 r / min for 10 min to obtain a water-based paint doped with modified inorganic particles.

[0053] Comparative Example 1

[0054] The modified inorganic particles in this comparative example are doped with water-based paint, and the preparation process is as follows:

[0055] (1) Dissolving citric acid in deionized water to obtain a citric acid solution, then dispersing nano titanium dioxide and rice husk powder in the citric acid solution, the mass ratio of citric acid, nano titanium dioxide and rice husk powder being 8:1:8, and then adjusting the pH to 7-8 using sodium hydroxide, and then sealing the solution in a reactor, heating to 225±5°C, keeping the temperature constant for 12 hours, cooling, taking out the reactant, washing and drying, and grinding to obtain modified particle 1;

[0056] (2) 40 parts of water-based acrylic resin, 10 parts of modified particles 1, 8 parts of polyvinyl alcohol, 0.2 parts of defoaming agent, and 0.3 parts of dispersant are added into a stirrer and stirred evenly at a stirring speed of 700 r / min for 15 min to obtain a water-based paint 1 doped with modified particles 1.

[0057] Comparative Example 2

[0058] The modified inorganic particles in this comparative example are doped with water-based paint, and the preparation process is as follows:

[0059] (1) impregnating polyimide particles in ammonium chloride with a concentration of 12 wt %, drying at low temperature (200±50° C.), and mixing with nano titanium dioxide particles in a mass ratio of 1:1 to obtain nano titanium dioxide flame retardant particles;

[0060] (2) Dissolving citric acid in deionized water to obtain a citric acid solution, and then dispersing nano titanium dioxide flame retardant particles and rice husk powder in the citric acid solution, the mass ratio of citric acid, nano titanium dioxide flame retardant particles and rice husk powder is 8:1:8, and then adjusting the pH to 7-8 with sodium hydroxide, and then sealing the solution in a reactor, heating to 225±5°C, keeping the temperature constant for 12 hours, cooling, taking out the reactants, washing and drying, and grinding to obtain modified particles II;

[0061] (3) Add 40 parts of water-based acrylic resin, 10 parts of modified particles 2, 8 parts of polyvinyl alcohol, 0.3 parts of defoaming agent, and 0.2 parts of dispersant into a stirrer and stir evenly at a stirring speed of 700 r / min for 15 min to obtain water-based paint 2 doped with modified particles 2.

[0062] Comparative Example 3

[0063] The modified inorganic particles in this comparative example are doped with water-based paint, and the preparation process is as follows:

[0064] (1) The polyimide particles are immersed in ammonium chloride with a concentration of 12 wt%, and then dried at low temperature (200±50°C) and mixed with nano-titanium dioxide particles in a mass ratio of 1:1. The mixture is placed in a vacuum carbonization furnace and continuously carbonized and graphitized in a nitrogen atmosphere. The carbonization treatment is performed at 920±10°C for 1 hour and the graphitization treatment is performed at 1900±10°C for 1 hour to obtain nano-titanium dioxide flame retardant particles;

[0065] (2) dispersing nano titanium dioxide flame retardant particles and rice husk powder in ethanol, with the mass ratio of nano titanium dioxide flame retardant particles to rice husk powder being 1:10, adjusting the pH to between 7 and 8, and then sealing the solution in a reactor, heating it to 225±5°C, keeping the temperature constant for 12 hours, taking out the reactants after cooling, washing and drying, and grinding to obtain modified particles three;

[0066] (3) Add 40 parts of water-based acrylic resin, 10 parts of modified particles three, 8 parts of polyvinyl alcohol, 0.5 parts of defoaming agent, and 1 part of dispersant into a stirrer, stir evenly at a stirring speed of 700 r / min for 15 min to obtain water-based paint three doped with modified particles three.

[0067] Comparative Example 4

[0068] The modified inorganic particles in this comparative example are doped with water-based paint, and the preparation process is as follows:

[0069] (1) The polyimide particles are immersed in ammonium chloride with a concentration of 12 wt%, and then dried at low temperature (200±50°C) and mixed with nano-titanium dioxide particles in a mass ratio of 1:1. The mixture is placed in a vacuum carbonization furnace and continuously carbonized and graphitized in a nitrogen atmosphere. The carbonization treatment is performed at 920±10°C for 1 hour and the graphitization treatment is performed at 1900±10°C for 1 hour to obtain nano-titanium dioxide flame retardant particles;

[0070] (2) dissolving citric acid in deionized water to obtain a citric acid solution, and then dispersing nano titanium dioxide flame retardant particles in the citric acid solution, the mass ratio of citric acid to nano titanium dioxide flame retardant particles is 10:1, and then adjusting the pH to between 7 and 8 with sodium hydroxide, and then sealing the solution in a reactor, heating to 225±5°C, keeping the temperature constant for 12 hours, cooling, taking out the reactants, washing and drying, and grinding to obtain modified particles four;

[0071] (3) Add 40 parts of water-based acrylic resin, 10 parts of modified particles four, 8 parts of polyvinyl alcohol, 0.5 parts of defoaming agent, and 0.8 parts of dispersant into a stirrer and stir evenly at a stirring speed of 700 r / min for 15 min to obtain a water-based paint four doped with modified particles four.

[0072] Comparative Example 5

[0073] The modified inorganic particles in this comparative example are doped with water-based paint, and the preparation process is as follows:

[0074] (1) The polyimide particles are immersed in ammonium chloride with a concentration of 12 wt%, and then dried at low temperature (200±50°C) and mixed with nano-titanium dioxide particles in a mass ratio of 1:1. The mixture is placed in a vacuum carbonization furnace and continuously carbonized and graphitized in a nitrogen atmosphere. The carbonization treatment is performed at 920±10°C for 1 hour and the graphitization treatment is performed at 1900±10°C for 1 hour to obtain nano-titanium dioxide flame retardant particles;

[0075] (2) dissolving citric acid in deionized water to obtain a citric acid solution, and then dispersing nano titanium dioxide flame retardant particles and rice husk powder in the citric acid solution, wherein the mass ratio of citric acid, nano titanium dioxide flame retardant particles and rice husk powder is 8:1:8, and washing and drying the precipitate after high-speed centrifugation to obtain modified particles 5;

[0076] (3) Add 40 parts of water-based acrylic resin, 10 parts of modified inorganic particles, 8 parts of polyvinyl alcohol, 0.1 parts of defoaming agent, and 0.8 parts of dispersant into a stirrer and stir evenly at a stirring speed of 700 r / min for 15 min to obtain a water-based paint five doped with modified particles five.

[0077] Comparative Example 6

[0078] The modified inorganic particles in this comparative example are doped with water-based paint, and the preparation process is as follows:

[0079] (1) The polyimide particles are immersed in ammonium chloride with a concentration of 12 wt %, and then dried at a low temperature (200±50° C.), and then mixed with nano-alumina particles in a mass ratio of 1:1. The mixture is placed in a vacuum carbonization furnace, and continuously carbonized and graphitized in a nitrogen atmosphere. The carbonization treatment is performed at 920±10° C. for 1 h, and the graphitization treatment is performed at 1900±10° C. for 1 h to obtain nano-alumina flame retardant particles;

[0080] (2) Dissolving citric acid in deionized water to obtain a citric acid solution, and then dispersing nano-alumina flame retardant particles and rice husk powder in the citric acid solution, wherein the mass ratio of citric acid, nano-alumina flame retardant particles and rice husk powder is 8:1:8, and then adjusting the pH to 7-8 using sodium hydroxide, and then sealing the solution in a reactor, heating it to 225±5°C, maintaining the temperature for 12 hours, cooling it, taking out the reactants, washing and drying them, and grinding them to obtain modified particles VI;

[0081] (3) Add 40 parts of water-based acrylic resin, 10 parts of modified particle six, 8 parts of polyvinyl alcohol, 0.2 parts of defoaming agent, and 0.2 parts of dispersant into a stirrer and stir evenly at a stirring speed of 700 r / min for 15 min to obtain water-based paint six doped with modified particle six.

[0082] 3. Water-based paint test

[0083] The water-based paints prepared in Examples 1-4 and Comparative Examples 1-6 were subjected to the following tests:

[0084] Antibacterial property: tested in accordance with the standard GB / T21866-2008 "Determination of antibacterial property and antibacterial effect of antibacterial coatings (paint films)";

[0085] Flame retardancy: The water-based paint prepared in the examples and comparative examples was stirred evenly and then sprayed onto a substrate with a release paper attached thereto. After spraying, the substrate was cured until a uniform and stable coating was formed on the substrate. The release paper was torn off to obtain a test sample. The limiting oxygen index of the water-based paint test sample was tested using an oxygen index meter.

[0086] Aging: The artificial weathering accelerated aging test was carried out for 1000 hours in accordance with GB / T 1865-2009 “Artificial weathering and artificial radiation exposure of paints and varnishes - filtered xenon arc radiation”.

[0087] Gloss: The water-based paint prepared in the examples and comparative examples was stirred evenly and then sprayed on the tinplate. After spraying, a curing operation was performed and baked at 100°C for 10 minutes to form a uniform and stable coating. The 60° gloss of the coating was tested using a 60° gloss meter.

[0088] The above test results are shown in the following table:

[0089]

[0090] Through the detection performance results in the above table, the following analysis conclusions can be drawn. The present invention adds modified inorganic particles to water-based paint, and uses citric acid, rice husk powder and nano titanium dioxide flame retardant particles for hydrothermal treatment, which may promote the generation of carbon quantum dots and graphene quantum dots, which increases the antibacterial durability of water-based paint on the one hand, and enhances the interaction between the modified inorganic particles and water-based polyurethane on the other hand. Graphene quantum dots have a zero-dimensional structure and are not easy to settle. Carbon quantum dots have excellent antibacterial effects, and nano titanium dioxide flame retardant particles, graphene quantum dots and carbon quantum dots combine with each other to form a continuous structure, which further improves the dispersibility of modified inorganic particles in water-based polyurethane, improves the bonding strength between modified inorganic particles and water-based acrylic resin, and enables the excellent properties of modified inorganic particles to be demonstrated, so that the overall performance of water-based paint is improved. Specifically,

[0091] The initial antibacterial rate of the water-based paint prepared in each embodiment and comparative example is 99%, indicating that the use of nano-inorganic materials (nano-titanium dioxide and nano-aluminum oxide) can make the water-based paint have excellent antibacterial properties. In particular, the modified inorganic particle-doped water-based paint prepared by the present invention has excellent antibacterial properties and antibacterial durability, especially the combination of citric acid, nano-titanium dioxide flame retardant particles, zinc oxide powder and rice husk powder, and its antibacterial durability always maintains a high level.

[0092] The modified inorganic particles in the present invention use nano titanium dioxide instead of nano aluminum oxide. Nano titanium dioxide can effectively increase the thermal decomposition temperature of the material and delay the thermal degradation process of the material. Compared with nano aluminum oxide, although it also has a flame retardant effect, its thermal conductivity is greater than that of nano titanium dioxide.

[0093] The antibacterial durability in Comparative Example 1 is reduced, but the reduction is smaller than that in Comparative Examples 2-6. The possible reason is that nano-titanium dioxide is not compounded with polyimide, and the amount added to the water-based paint is sufficient, so that the nano-titanium dioxide can exert its own antibacterial effect and excellent gloss, but its flame retardant and anti-aging properties are not as good as other comparative examples; in Comparative Example 2, since polyimide and nano-titanium dioxide are mixed and not heat-treated, a graphitized structure is not formed in its structure, the amount of nano-titanium dioxide is reduced, and the antibacterial durability is weak; and polyimide particles are used instead of nano-titanium dioxide as a flame retardant component, and the flame retardancy of polyimide is enhanced by high-temperature treatment of polyimide particles and nano-titanium dioxide particles, the amount of nano-titanium dioxide can be reduced, and the application in water-based paint can also enhance the anti-aging properties of water-based paint.

[0094] The reason why the performance of Comparative Examples 3, 4 and 5 has decreased greatly and with the same magnitude may be that the complex continuous structure has not been formed, resulting in poor dispersibility of the modified inorganic particles, and the combination with the water-based acrylic resin has deteriorated, so that the properties of the nanoparticles themselves cannot be fully exerted, thereby affecting the antibacterial durability, flame retardancy and aging of the water-based paint, and even if the amount of dispersant is increased, the dispersion effect is not ideal. However, the glossiness of Comparative Examples 3, 4 and 5 is still maintained, indicating that the poor dispersibility has little effect on the glossiness of the water-based paint. Comparative Example 6 uses nano-alumina and undergoes the same preparation process as the nano-titanium dioxide of the present invention, but its antibacterial durability is not as good as that of nano-titanium dioxide, indicating that the performance of the modified inorganic particles of the present invention is more stable. Under the same treatment process, the surface glossiness of the nano-alumina water-based paint is about 10% darker than that of the water-based paint of the present invention.

[0095] In summary, the modified inorganic particles proposed in the present invention are applied to water-based paint, which has a good improvement on the antibacterial, flame retardant, anti-aging and gloss properties of the water-based paint, providing a research basis for expanding the application scope of water-based paint.

[0096] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A modified inorganic particle doped water-based paint, characterized in that: The raw materials for preparing the water-based paint include, by weight, 35-50 parts of water-based acrylic resin, 5-10 parts of modified inorganic particles, 8-12 parts of polyvinyl alcohol, 0.1-0.5 parts of defoaming agent, and 0.1-0.5 parts of dispersant; The modified inorganic particles are obtained by mixing nano titanium dioxide flame retardant particles, citric acid and biomass powder and subjecting them to hydrothermal treatment, and the nano titanium dioxide flame retardant particles are obtained by subjecting polyimide particles and nano titanium dioxide particles to heat treatment; specifically as follows: The preparation process of the nano titanium dioxide flame retardant particles is as follows: the polyimide particles are immersed in ammonium chloride with a concentration of 10-12wt%, dried and mixed with nano titanium dioxide, and the mixture is continuously subjected to carbonization and graphitization heat treatment in a nitrogen atmosphere; The preparation of the modified inorganic particles comprises the following steps: The citric acid is dissolved in deionized water to obtain a citric acid solution, and then the nano titanium dioxide flame retardant particles and biomass powder are dispersed in the citric acid solution, and then the pH is adjusted to 7-8 with sodium hydroxide, and then the solution is sealed in a reactor, heated to 220-230°C, kept at a constant temperature for 12-48 hours, and the reactants are taken out after cooling, washed and dried.

2. The modified inorganic particle doped water-based paint according to claim 1, characterized in that: The carbonization treatment is carried out at a temperature of 900-950° C. for 0.5-1 h, and the graphitization treatment is carried out at a temperature of 1800-2000° C. for 0.5-1 h.

3. The modified inorganic particle doped water-based paint according to claim 1, characterized in that: The mixing mass ratio of the polyimide particles and nano-titanium dioxide is (1-3):

1.

4. The modified inorganic particle doped water-based paint according to claim 1, characterized in that: The mass ratio of the citric acid, the nano titanium dioxide flame retardant particles and the biomass powder is (5-10):1:(5-10).

5. The modified inorganic particle doped water-based paint according to claim 4, characterized in that: The raw material of the biomass powder is one of corn stalks, rice husks, bamboo or soybean stalks.

6. The modified inorganic particle doped water-based paint according to claim 4, characterized in that: When preparing the modified inorganic particles, the method also includes dispersing zinc oxide powder, nano titanium dioxide flame retardant particles and biomass powder in a citric acid solution, wherein the amount of the zinc oxide powder is 20-30% of the nano titanium dioxide flame retardant particles.

7. A method for preparing a water-based paint doped with modified inorganic particles according to any one of claims 1 to 6, characterized in that: Add 35-50 parts of water-based acrylic resin, 5-10 parts of modified inorganic particles, 8-12 parts of polyvinyl alcohol, 0.1-0.5 parts of defoaming agent and 0.1-0.5 parts of dispersant into a stirrer and stir evenly at a stirring speed of 600-800 r / min and a stirring time of 10-15 min to obtain a water-based paint doped with modified inorganic particles.

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