A net aldehyde latex paint and a preparation method thereof

Abstract

The present application provides a kind of net aldehyde latex paint and its preparation method, by the catalyst of chemical synthesis of graphene oxide, silica aerogel, doped nano titanium dioxide and other substances as functional filler is added to acrylic emulsion, cooperate color filler, auxiliary agent, water-based color paste and deionized water, so that net aldehyde latex paint with excellent formaldehyde purification efficiency and purification durability under normal temperature and visible light is prepared.The net aldehyde latex paint provided by the present application can solve the problems of low formaldehyde purification efficiency, short duration, catalytic temperature and other problems existing in the existing net aldehyde latex paint, and the preparation process is simple, not only can quickly and continuously remove indoor harmful substances such as formaldehyde, but also has good environmental performance, and has little influence on human body and environment during production and construction.

Description

Technical Field

[0001] This invention relates to a latex paint, and more particularly to a formaldehyde-free latex paint and its preparation method. Background Technology

[0002] In modern society, with the acceleration of industrialization and the improvement of people's living standards, various materials used in interior decoration and furniture manufacturing, such as artificial boards, paints, and adhesives, often release harmful substances such as formaldehyde, which pose a serious threat to human health. Formaldehyde is a colorless, irritating gas with strong carcinogenic and teratogenic effects. Long-term exposure may cause discomfort in the eyes, nose, and throat, and even lead to respiratory and blood diseases. Therefore, reducing indoor formaldehyde pollution and protecting people's health has become one of the urgent social problems to be solved.

[0003] Against this backdrop, the research and application of formaldehyde-reducing latex paint is particularly important. This type of paint, by adding special ingredients such as photocatalysts, activated carbon, and nanomaterials, can effectively adsorb and decompose formaldehyde in the indoor environment, converting it into harmless water and carbon dioxide, thereby purifying indoor air and improving the comfort and safety of the living environment. Research on formaldehyde-reducing latex paint involves multiple disciplines, including materials science, chemical engineering, and environmental science, and also needs to consider the paint's environmental friendliness, economy, and practicality to meet market and consumer demands.

[0004] However, the research and application of formaldehyde-removing latex paint also face some challenges. For example, how to improve the formaldehyde removal efficiency of the paint, how to ensure the long-term stability and safety of the paint, and how to reduce production costs to make it more widespread and economical. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a formaldehyde-removing latex paint that can solve the problems of low formaldehyde purification efficiency, short duration and high catalytic temperature of existing formaldehyde-removing latex paints.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A formaldehyde-free latex paint is made from the following raw materials in parts by weight: 40-50 parts acrylic emulsion, 3-6 parts catalyst, 20-30 parts pigments and fillers, 5-7 parts functional additives, 2-4 parts water-based color paste, and 13-19 parts deionized water.

[0008] This invention uses acrylic emulsion as the base material for latex paint. Acrylic emulsion has good water resistance, alkali resistance, and stain resistance, and exhibits good adhesion to brick, wood, and steel surfaces. Furthermore, the acrylic emulsion used in this invention is preferably at least one of pure acrylic emulsion, styrene-acrylic emulsion, and vinyl acetate-acrylic emulsion.

[0009] Furthermore, the catalyst of the present invention is prepared by the following steps:

[0010] An aminosilane coupling agent and polyetheramine were dissolved in an ethanol-water solution. Then, graphene oxide powder, silica aerogel powder, and doped nano-titanium dioxide powder were added. The mixture was heated under reflux and stirred for 5-8 hours. After the reaction, it was allowed to cool to room temperature, repeatedly filtered and washed with deionized water, and then freeze-dried for 12-24 hours before grinding to obtain the catalyst. The silica aerogel powder, with its extremely high porosity and specific surface area, can improve the catalyst's adsorption capacity for formaldehyde. Furthermore, the aminosilane coupling agent reacts with the hydroxyl groups on its surface, enhancing its dispersibility in aqueous emulsions. In addition, the aminosilane coupling agent also reduces and modifies the surface of graphene oxide. The reduced graphene oxide not only has a higher affinity for formaldehyde but also exhibits excellent photothermal, ultraviolet light absorption, and electronic conductivity properties, which can enhance the photocatalytic degradation performance of doped nano-titanium dioxide particles for formaldehyde. When titanium dioxide is irradiated with ultraviolet light, electrons on its surface are excited, transitioning from the valence band to the conduction band, forming photogenerated electrons and holes. These photogenerated electrons and holes then react with water molecules or oxygen adsorbed on the catalyst surface during migration, generating highly oxidizing active substances such as hydroxyl radicals or superoxide radicals. Finally, these active substances react with formaldehyde molecules in the air in a redox reaction, gradually oxidizing and decomposing formaldehyde into carbon dioxide and water. Furthermore, doping with elements such as nitrogen, iron, and manganese gives titanium dioxide a narrower band gap, allowing electrons to be excited and catalyzing formaldehyde degradation under visible light, thus improving its utilization of natural light. In addition, aminosilane coupling agents and polyetheramines can modify and alter the surface of doped nano-titanium dioxide, promoting its dispersion while polyetheramines can also adhere it to the surface of reduced graphene oxide. Polyetheramines can not only reduce graphene oxide but also crosslink reduced graphene oxide nanosheets supported by doped titanium dioxide, connecting the nanosheets and forming a reduced graphene oxide aerogel supported by doped titanium dioxide after drying. By crosslinking the reduced graphene oxide nanosheets to form a three-dimensional aerogel structure, agglomeration of the nanosheets in aqueous emulsions is avoided, and a larger specific surface area and more adsorption sites for doped titanium dioxide and formaldehyde are generated, thereby improving the catalytic activity of the doped titanium dioxide. Therefore, under the combined action of the reduced graphene oxide aerogel supported by doped titanium dioxide and the silica aerogel, the catalyst exhibits excellent formaldehyde adsorption and catalytic degradation, demonstrating ultra-high formaldehyde purification efficiency and long-lasting purification.

[0011] Further, in the preparation step of the catalyst described in this invention, the aminosilane coupling agent is preferably at least one of a monoaminosilane coupling agent, a diaminosilane coupling agent, and a triaminosilane coupling agent; the ethanol aqueous solution is used for the dissolution and hydrolysis of the aminosilane coupling agent, as well as the solution in the liquid-phase synthesis system, and its volume fraction is preferably 50-75%; the average number-average molecular weight of the polyetheramine is preferably 230-2000 g / mol; the sheet diameter of the graphene oxide is preferably 0.2-50 μm; the particle size of the silica aerogel powder is preferably 5-50 μm; and the doped nano-titanium dioxide powder is preferably nitrogen-doped nano-titanium dioxide powder. At least one of titanium dioxide, iron-doped nano-titanium dioxide, and manganese-doped nano-titanium dioxide, with a particle size preferably of 5-30 nm; the mass ratio of aminosilane coupling agent, polyetheramine, ethanol aqueous solution, graphene oxide powder, silica aerogel powder, and doped nano-titanium dioxide powder is preferably (1-2):(3-5):100:(2-3):(0.5-1):(8-10); the heating temperature is preferably 65-75℃, the stirring speed is preferably 400-600 rpm, the freeze-drying temperature is preferably -10℃, and the mesh size of the catalyst after grinding is preferably 100-200 mesh.

[0012] The pigments and fillers used in this invention not only provide basic color and hiding power for latex paint, but also enhance the physical and chemical properties of the latex paint. Furthermore, the pigments and fillers used in this invention are preferably at least one of titanium dioxide, kaolin, and heavy calcium carbonate.

[0013] The functional additives used in this invention have functions such as assisting in the dispersion of pigments, fillers, and catalysts, defoaming, assisting in film formation, and adjusting pH and viscosity. Further, the functional additives of this invention are preferably at least one of dispersants, defoamers, film-forming aids, pH adjusters, and thickeners.

[0014] The water-based colorant used in this invention is for adjusting the color of latex paint. Further, the water-based colorant of this invention is at least one of water-based organic colorant and water-based inorganic colorant.

[0015] Another technical problem to be solved by the present invention is to provide a method for preparing the above-mentioned formaldehyde-free latex paint.

[0016] To solve the above technical problems, the technical solution is as follows:

[0017] A method for preparing a formaldehyde-free latex paint includes the following steps:

[0018] Weigh each raw material according to the mass fraction, mix the acrylic emulsion, catalyst, pigments and fillers, functional additives, water-based color paste and deionized water, and stir for 60-120 minutes to obtain formaldehyde-free latex paint.

[0019] Furthermore, the stirring speed of the present invention is preferably 1000-1500 rpm.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The formaldehyde-removing latex paint provided by the present invention enhances the photocatalytic performance of doped nano-titanium dioxide by reducing graphene oxide and enhances the adsorption of formaldehyde by silica aerogel. Therefore, it has excellent formaldehyde purification efficiency (greater than 93%) and purification durability (R6 greater than 83%) under visible light, and can quickly and continuously remove harmful substances such as formaldehyde in the room and improve indoor air quality.

[0022] (2) The aldehyde-free latex paint preparation process provided by the present invention is simple, and it uses water as a medium with low organic solvent content. It has little impact on human health and the environment during production and construction, and belongs to the category of water-based coatings. Therefore, it has good environmental protection properties. Detailed Implementation

[0023] The present invention will now be described in detail with reference to specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0024] Example 1

[0025] Prepare formaldehyde-free latex paint A according to the following steps:

[0026] S1. An aminosilane coupling agent (1g, 3-aminopropylmethyldimethoxysilane) and a polyetheramine (4g, Adamas D-400, average number-average molecular weight 400) were dissolved in an ethanol aqueous solution (100g, volume fraction 75%). Then, graphene oxide powder (2g, sheet diameter 0.2-10μm, Suzhou Carbonfeng Technology), silica aerogel powder (0.5g, particle size 20μm, Suzhou Kangmai New Materials), and doped nano titanium dioxide powder (9g, nitrogen-doped nano titanium dioxide, particle size 10nm, nitrogen content 4wt%, Zhejiang Zhitai Nano Micro New Materials Co., Ltd.) were added. The mixture was stirred under reflux for 8h (heating temperature 75℃, stirring speed 500rpm). After the reaction was completed, the mixture was allowed to stand and cool to room temperature. It was repeatedly filtered and washed with deionized water, freeze-dried at -10℃ for 24h, and ground through a 150-mesh sieve to obtain catalyst A.

[0027] S2. Mix acrylic emulsion (45g, pure acrylic emulsion, Chunyi Chemical GH3712), catalyst A (4g), pigments and fillers (titanium dioxide (5g, Chemours R902), kaolin (10g, Lehuan 4000), heavy calcium carbonate (10g, Jialiang Minerals JLCA-93)), functional additives (dispersant (2g, Nopco SN-5027), defoamer (1g, Evonik SURFYNOL 104E), film-forming aid (2g, alcohol ester dodecyl, Eastman), pH adjuster (0.5g, Dow AMP-95), thickener (0.5g, Dow ASE-60)), water-based color paste (3g, water-based carbon black paste, Clariant KA100N131-CN) and deionized water (17g), and stir (stirring speed 1200rpm) for 60min to obtain formaldehyde-free latex paint A.

[0028] Example 2

[0029] Prepare formaldehyde-free latex paint B according to the following steps:

[0030] S1. Dissolve aminosilane coupling agent (2g, 3-aminopropylmethyldiethoxysilane) and polyetheramine (3g, Adamas D-230, average number-average molecular weight 230) in ethanol aqueous solution (100g, volume fraction 50%), then add graphene oxide powder (2.5g, sheet diameter 0.5-5μm, Suzhou Carbonfeng Technology), silica aerogel powder (0.5g, particle size 15μm, Shenzhen Zhongning Technology), and doped nano titanium dioxide powder (8g, iron-doped nano titanium dioxide, particle size 5nm, iron content 5wt%, Zhejiang Zhitai Nano Micro New Materials Co., Ltd.). Stir and react under reflux for 5h (heating temperature 65℃, stirring speed 600rpm). After the reaction is completed, let stand and cool to room temperature, repeatedly filter and wash with deionized water, freeze dry at -10℃ for 12h, and grind through a 100-mesh sieve to obtain catalyst B.

[0031] S2. Mix acrylic emulsion (50g, styrene-acrylic emulsion, Suixin Chemical 7199), catalyst B (6g), pigments and fillers (titanium dioxide (6g, Chemours R902), kaolin (8g, Lehuan 4000), heavy calcium carbonate (6g, Jialiang Minerals JLCA-93)), functional additives (dispersant (2g, BYK Chemical Disperbyk-194), defoamer (1.5g, BASF 2410), film-forming aid (2g, dipropylene glycol methyl ether, Dow), pH adjuster (0.5g, Dow AMP-95), thickener (1g, Dow TT-935)), water-based color paste (4g, water-based phthalocyanine green paste, Gudao Technology 37G) and deionized water (13g), and stir (stirring speed 1500rpm) for 120min to obtain formaldehyde-free latex paint B.

[0032] Example 3

[0033] Prepare formaldehyde-free latex paint C according to the following steps:

[0034] S1. An aminosilane coupling agent (1.5g, N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane) and a polyetheramine (5g, Adamas D-2000, average number-average molecular weight 2000) were dissolved in an ethanol aqueous solution (100g, volume fraction 75%). Then, graphene oxide powder (3g, sheet diameter 0.2-10μm, Suzhou Carbonfeng Technology), silica aerogel powder (1g, particle size 50μm, Shenzhen Zhongning Technology), and doped nano titanium dioxide powder (8g, manganese-doped nano titanium dioxide, particle size 10nm, manganese content 5wt%, Zhejiang Zhitai Nano Micro New Materials Co., Ltd.) were added. The mixture was stirred under reflux for 6h (heating temperature 75℃, stirring speed 400rpm). After the reaction was completed, the mixture was allowed to stand and cool to room temperature. It was repeatedly filtered and washed with deionized water, freeze-dried at -10℃ for 18h, and ground through a 200-mesh sieve to obtain catalyst C.

[0035] S2. Mix acrylic emulsion (40g, vinyl acetate emulsion, Baolijia Chemical BLJ-3359), catalyst C (5g), pigments and fillers (titanium dioxide (10g, Chemours R902), kaolin (10g, Lehuan 4000), heavy calcium carbonate (10g, Jialiang Minerals JLCA-93)), functional additives (dispersant (2g, Yoshida Chemical X-405), defoamer (1.5g, Dygo Airex 902W), film-forming aid (2g, dipropylene glycol methyl ether, Dow), pH adjuster (0.5g, Dow AMP-95), thickener (1g, Yoshida Chemical 2521)), water-based color paste (2g, water-based phthalocyanine blue paste, Gudao Technology 3153) and deionized water (16g), and stir (stirring speed 1000rpm) for 90min to obtain formaldehyde-free latex paint C.

[0036] Example 4

[0037] Prepare formaldehyde-free latex paint D according to the following steps:

[0038] S1. An aminosilane coupling agent (2g, γ-diethylenetriaminopropyltrimethoxysilane) and a polyetheramine (5g, Adamas D-400, average number-average molecular weight 400) were dissolved in an ethanol aqueous solution (100g, volume fraction 60%). Then, graphene oxide powder (2g, sheet diameter 10-50μm, Suzhou Carbonfeng Technology), silica aerogel powder (0.5g, particle size 5μm, Suzhou Kangmai New Materials), and doped nano titanium dioxide powder (10g, nitrogen-doped nano titanium dioxide, particle size 5nm, nitrogen content 4wt%, Zhejiang Zhitai Nano Micro New Materials Co., Ltd.) were added. The mixture was stirred under reflux for 7h (heating temperature 75℃, stirring speed 600rpm). After the reaction was completed, the mixture was allowed to stand and cool to room temperature. It was repeatedly filtered and washed with deionized water, freeze-dried at -10℃ for 15h, and ground through a 150-mesh sieve to obtain catalyst D.

[0039] S2. Mix acrylic emulsion (48g, pure acrylic emulsion, Chunyi Chemical GH3712), catalyst D (3g), pigments and fillers (titanium dioxide (10g, Chemours R902), kaolin (10g, Lehuan 4000), heavy calcium carbonate (7g, Jialiang Minerals JLCA-93)), functional additives (dispersant (1.5g, Nopco SN-5040), defoamer (0.5g, Dyco FOAMEX 830), film-forming aid (2g, alcohol ester dodecyl, Eastman), pH adjuster (0.5g, Dow AMP-95), thickener (0.5g, Dow TT-935)), water-based color paste (3g, organic yellow paste, Clariant 2GXD130) and deionized water (14g), and stir (stirring speed 1300rpm) for 100min to obtain formaldehyde-free latex paint D.

[0040] Example 5

[0041] Prepare formaldehyde-free latex paint E according to the following steps:

[0042] S1. An aminosilane coupling agent (1g, γ-aminopropyltriethoxysilane) and a polyetheramine (3g, Adamas D-230, average number-average molecular weight 230) were dissolved in an ethanol aqueous solution (100g, volume fraction 70%). Then, graphene oxide powder (3g, sheet diameter 0.2-10μm, Suzhou Carbonfeng Technology), silica aerogel powder (1g, particle size 30μm, Suzhou Kangmai New Materials), and doped nano titanium dioxide powder (9g, iron-doped nano titanium dioxide, particle size 10nm, iron content 5wt%, Zhejiang Zhitai Nano Micro New Materials Co., Ltd.) were added. The mixture was heated under reflux and stirred for 8h (heating temperature 70℃, stirring speed 500rpm). After the reaction was completed, the mixture was allowed to stand and cool to room temperature. It was repeatedly filtered and washed with deionized water, freeze-dried at -10℃ for 20h, and ground through a 150-mesh sieve to obtain catalyst B.

[0043] S2. Mix acrylic emulsion (43g, pure acrylic emulsion, Chunyi Chemical GH3712), catalyst E (6g), pigments and fillers (titanium dioxide (8g, Chemours R902), kaolin (6g, Lehuan 4000), heavy calcium carbonate (8g, Jialiang Minerals JLCA-93)), functional additives (dispersant (2g, BYK Chemical Disperbyk-194), defoamer (1g, Dow Corning DC-62), film-forming aid (2g, alcohol ester dodecyl, Eastman), pH adjuster (0.5g, Dow AMP-95), thickener (0.5g, Dow TT-935)), water-based pigment (4g, water-based titanium dioxide, Gudao Technology 9570)) and deionized water (19g), and stir (stirring speed 1300rpm) for 100min to obtain formaldehyde-free latex paint E.

[0044] Comparative Example 1

[0045] Prepare a formaldehyde-free latex paint without graphene oxide by following these steps:

[0046] S1. An aminosilane coupling agent (1g, 3-aminopropylmethyldimethoxysilane) and a polyetheramine (4g, Adamas D-400, average number-average molecular weight 400) were dissolved in an ethanol aqueous solution (100g, volume fraction 75%). Then, silica aerogel powder (0.5g, particle size 20μm, Suzhou Kangmai New Materials) and doped nano titanium dioxide powder (9g, nitrogen-doped nano titanium dioxide, particle size 10nm, nitrogen content 4wt%, Zhejiang Zhitai Nano Micro New Materials Co., Ltd.) were added. The mixture was stirred under reflux for 8 hours (heating temperature 75℃, stirring speed 500rpm). After the reaction was completed, the mixture was allowed to stand and cool to room temperature. It was repeatedly filtered and washed with deionized water, freeze-dried at -10℃ for 24 hours, and ground through a 150-mesh sieve to obtain a catalyst without graphene oxide.

[0047] S2. Mix acrylic emulsion (45g, pure acrylic emulsion, Chunyi Chemical GH3712), graphene-free catalyst (4g), pigments and fillers (titanium dioxide (5g, Chemours R902), kaolin (10g, Lehuan 4000), heavy calcium carbonate (10g, Jialiang Minerals JLCA-93)), functional additives (dispersant (2g, Nopco SN-5027), defoamer (1g, Evonik SURFYNOL 104E), film-forming aid (2g, alcohol ester dodecyl, Eastman), pH adjuster (0.5g, Dow AMP-95), thickener (0.5g, Dow ASE-60)), water-based color paste (3g, water-based carbon black paste, Clariant KA100N131-CN) and deionized water (17g), and stir (stirring speed 1200rpm) for 60min to obtain a graphene-free formaldehyde-free latex paint.

[0048] Comparative Example 2

[0049] Prepare a formaldehyde-free latex paint without silica aerogel by following these steps:

[0050] S1. An aminosilane coupling agent (1g, 3-aminopropylmethyldimethoxysilane) and a polyetheramine (4g, Adamas D-400, average number-average molecular weight 400) were dissolved in an ethanol aqueous solution (100g, volume fraction 75%). Then, graphene oxide powder (2g, sheet diameter 0.2-10μm, Suzhou Carbon-rich Technology) and doped nano-titanium dioxide powder (9g, nitrogen-doped nano-titanium dioxide, particle size 10nm, nitrogen content 4wt%, Zhejiang Zhitai Nano-Micro New Materials Co., Ltd.) were added. The mixture was stirred under reflux for 8h (heating temperature 75℃, stirring speed 500rpm). After the reaction was completed, the mixture was allowed to stand and cool to room temperature. It was repeatedly filtered and washed with deionized water, freeze-dried at -10℃ for 24h, and ground through a 150-mesh sieve to obtain a catalyst without silica aerogel.

[0051] S2. Mix acrylic emulsion (45g, pure acrylic emulsion, Chunyi Chemical GH3712), silica aerogel-free catalyst (4g), pigments and fillers (titanium dioxide (5g, Chemours R902), kaolin (10g, Lehuan 4000), heavy calcium carbonate (10g, Jialiang Minerals JLCA-93)), functional additives (dispersant (2g, Nopco SN-5027), defoamer (1g, Evonik SURFYNOL 104E), film-forming aid (2g, alcohol ester dodecyl, Eastman), pH adjuster (0.5g, Dow AMP-95), thickener (0.5g, Dow ASE-60)), water-based color paste (3g, water-based carbon black paste, Clariant KA100N131-CN) and deionized water (17g), and stir (stirring speed 1200rpm) for 60min to obtain silica aerogel-free formaldehyde-free latex paint.

[0052] Comparative Example 3

[0053] Prepare a formaldehyde-free latex paint containing undoped nano-titanium dioxide according to the following steps:

[0054] S1. An aminosilane coupling agent (1g, 3-aminopropylmethyldimethoxysilane) and a polyetheramine (4g, Adamas D-400, average number-average molecular weight 400) were dissolved in an ethanol aqueous solution (100g, volume fraction 75%). Then, graphene oxide powder (2g, sheet diameter 0.2-10μm, Suzhou Carbon-rich Technology), silica aerogel powder (0.5g, particle size 20μm, Suzhou Kangmai New Materials), and undoped nano titanium dioxide powder (9g, anatase hydrophilic 99.8%, particle size 5-10nm, Maclean) were added. The mixture was stirred under reflux for 8 hours (heating temperature 75℃, stirring speed 500rpm). After the reaction was completed, the mixture was allowed to stand and cool to room temperature. It was repeatedly filtered and washed with deionized water, freeze-dried at -10℃ for 24 hours, and ground through a 150-mesh sieve to obtain a catalyst containing undoped nano titanium dioxide.

[0055] S2. Acrylic emulsion (45g, pure acrylic emulsion, Chunyi Chemical GH3712), catalyst containing undoped nano titanium dioxide (4g), pigments and fillers (titanium dioxide (5g, Chemours R902), kaolin (10g, Lehuan 4000), heavy calcium carbonate (10g, Jialiang Minerals JLCA-93)), functional additives (dispersant (2g, Nopco SN-5027), defoamer (1g, Evonik SURFYN)). OL104E), film-forming aid (2g, 12-ol ester, Eastman), pH adjuster (0.5g, Dow AMP-95), thickener (0.5g, Dow ASE-60)), water-based pigment (3g, water-based carbon black pigment, Clariant KA100N131-CN) and deionized water (17g) were mixed and stirred (stirring speed 1200rpm) for 60min to obtain a formaldehyde-free latex paint containing undoped nano-titanium dioxide.

[0056] Comparative Example 4

[0057] Prepare bamboo charcoal powder formaldehyde-removing latex paint according to the following steps:

[0058] Acrylic emulsion (45g, pure acrylic emulsion, Chunyi Chemical GH3712), bamboo charcoal powder (4g, 1000 mesh particle size), pigments and fillers (titanium dioxide (5g, Chemours R902), kaolin (10g, Lehuan 4000), heavy calcium carbonate (10g, Jialiang Minerals JLCA-93)), functional additives (dispersant (2g, Nopco SN-5027), defoamer (1g, Evonik SURFYNOL 104E), film-forming aid (2g, alcohol ester dodecyl, Eastman), pH adjuster (0.5g, Dow AMP-95), thickener (0.5g, Dow ASE-60)), water-based color paste (3g, water-based carbon black paste, Clariant KA100N131-CN) and deionized water (17g) were mixed and stirred (stirring speed 1200rpm) for 60min to obtain bamboo charcoal powder formaldehyde-free latex paint.

[0059] Comparative Example 5

[0060] Prepare latex paint without added formaldehyde-removing materials by following these steps:

[0061] Acrylic emulsion (45g, pure acrylic emulsion, Chunyi Chemical GH3712), pigments and fillers (titanium dioxide (9g, Chemours R902), kaolin (10g, Lehuan 4000), heavy calcium carbonate (10g, Jialiang Minerals JLCA-93)), functional additives (dispersant (2g, Nopco SN-5027), defoamer (1g, Evonik SURFYNOL 104E), film-forming aid (2g, alcohol ester dodecyl, Eastman), pH adjuster (0.5g, Dow AMP-95), thickener (0.5g, Dow ASE-60)), water-based color paste (3g, water-based carbon black paste, Clariant KA100N131-CN)) and deionized water (17g) were mixed and stirred (stirring speed 1200rpm) for 60min to obtain a latex paint without added formaldehyde-removing materials.

[0062] Experimental example:

[0063] The latex paints prepared in Examples 1-5 and Comparative Examples 1-5 were used to prepare test samples according to the standard "JC / T 1074-2021 Purification Performance of Indoor Air Purification Functional Coating Materials" (Class 1S). Formaldehyde was selected as the target pollutant, and the purification principle was tested according to the photocatalytic air purification function of the coating material (Type G, visible light source). The test results are shown in Table 1.

[0064] Table 1

[0065] Formaldehyde purification efficiency, % Purification persistence R6, % in the sixth test cycle Example 1 95.9 85.7 Example 2 96.2 86.2 Example 3 94.8 83.9 Example 4 93.7 84.8 Example 5 94.5 85.3 Comparative Example 1 82.2 72.3 Comparative Example 2 78.9 60.9 Comparative Example 3 79.9 67.4 Comparative Example 4 60.8 30.2 Comparative Example 5 41.2 20.5

[0066] As can be seen from Table 1, the formaldehyde purification efficiency and purification durability of Examples 1-5 in the sixth test cycle are significantly higher than those of Comparative Examples 1-5. This indicates that, under the synergistic effect of graphene oxide, silica aerogel, and doped nano-titanium dioxide, the formaldehyde-removing latex paint prepared in this invention has superior formaldehyde purification efficiency and purification durability under visible light and room temperature conditions compared to formaldehyde-removing latex paint without graphene oxide, formaldehyde-removing latex paint without silica aerogel, formaldehyde-removing latex paint containing undoped nano-titanium dioxide, bamboo charcoal powder formaldehyde-removing latex paint, and latex paint without added purification materials.

[0067] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A formaldehyde-free latex paint, characterized in that: It is made from the following raw materials in parts by weight: 40-50 parts acrylic emulsion, 3-6 parts catalyst, 20-30 parts pigments and fillers, 5-7 parts functional additives, 2-4 parts water-based color paste, and 13-19 parts deionized water. The catalyst is prepared by the following steps: The aminosilane coupling agent and polyetheramine were dissolved in an aqueous ethanol solution, and then graphene oxide powder, silica aerogel powder, and doped nano titanium dioxide powder were added. The mixture was heated under reflux and stirred for 5-8 hours. After the reaction was completed, the mixture was allowed to stand and cool to room temperature. It was then repeatedly filtered and washed with deionized water, freeze-dried for 12-24 hours, and then ground to obtain the catalyst. The mass ratio of aminosilane coupling agent, polyetheramine, aqueous ethanol solution, graphene oxide powder, silica aerogel powder, and doped nano titanium dioxide powder was (1-2):(3-5):100:(2-3):(0.5-1):(8-10).

2. The formaldehyde-free latex paint according to claim 1, characterized in that: The acrylic emulsion is at least one of pure acrylic emulsion, styrene-acrylic emulsion, and vinyl acetate-acrylic emulsion.

3. The formaldehyde-free latex paint according to claim 1, characterized in that: In the catalyst preparation steps, the aminosilane coupling agent is at least one of monoaminosilane coupling agent, diaminosilane coupling agent, and triaminosilane coupling agent; the volume fraction of the ethanol aqueous solution is 50-75%; the average number-average molecular weight of the polyetheramine is 230-2000 g / mol; the sheet diameter of the graphene oxide is 0.2-50 μm; the particle size of the silica aerogel powder is 5-50 μm; the doped nano-titanium dioxide powder is at least one of nitrogen-doped nano-titanium dioxide, iron-doped nano-titanium dioxide, and manganese-doped nano-titanium dioxide, with a particle size of 5-30 nm; the heating temperature is 65-75℃, the stirring speed is 400-600 rpm, the freeze-drying temperature is -10℃, and the mesh size of the catalyst after grinding is 100-200 mesh.

4. The formaldehyde-free latex paint according to claim 1, characterized in that: The pigments and fillers are at least one of titanium dioxide, kaolin, and heavy calcium carbonate.

5. The formaldehyde-free latex paint according to claim 1, characterized in that: The functional additive is at least one of the following: dispersant, defoamer, film-forming aid, pH adjuster, and thickener.

6. The formaldehyde-free latex paint according to claim 1, characterized in that: The water-based color paste is at least one of water-based organic color paste and water-based inorganic color paste.

7. A method for preparing a formaldehyde-free latex paint according to any one of claims 1 to 6, characterized in that: Includes the following steps: Weigh each raw material according to the mass fraction, mix the acrylic emulsion, catalyst, pigments and fillers, functional additives, water-based color paste and deionized water, and stir for 60-120 minutes to obtain formaldehyde-free latex paint.

8. The method for preparing a formaldehyde-free latex paint according to claim 7, characterized in that: The stirring speed is 1000-1500 rpm.