Antifouling high-hardness nano porcelainized paint and preparation method thereof

Abstract

The invention relates to the technical field of coatings, and particularly discloses an antifouling high-hardness nano porcelain paint and a preparation method thereof. The antifouling high-hardness nano porcelainized paint is prepared from the following components in parts by weight: 90 to 120 parts of acrylate emulsion, 40 to 60 parts of nano inorganic silicon resin, 5 to 10 parts of coalescing agent, 20 to 30 parts of titanium dioxide, 10 to 20 parts of filler, 0.5 to 2 parts of aldehyde removal additive, 2 to 3 parts of dispersing agent, 0.5 to 1.5 parts of defoaming agent, 1 to 2 parts of thickening agent and 10 to 20 parts of water, the solid content of the acrylate emulsion is 46-48%, and the acrylate emulsion is prepared from the following raw materials: a mixed monomer composed of methyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate and methacrylic acid, a functional monomer composed of triethoxysilane succinic anhydride, a crosslinking monomer composed of diacetone acrylamide and dihydrazine adipate, an emulsifier, an initiator and water. By improving the film-forming compactness of the coating system, the anti-fouling performance and hardness of the porcelainized paint can be improved at the same time.

Description

Technical Field

[0001] The present application relates to the technical field of coatings, and more specifically, to an antifouling high-hardness nano-ceramic paint and a preparation method thereof. Background Art

[0002] With the rapid development of modern architecture, automotive manufacturing, and home decoration, the market is placing higher demands on the comprehensive performance of high-performance coatings. Traditional coatings often struggle to meet increasingly stringent application requirements in terms of hardness, stain resistance, weather resistance, and environmental performance. For example, while conventional acrylic coatings offer advantages such as strong adhesion and good weather resistance, they suffer from a poor balance between hardness and stain resistance, making them susceptible to scratches and residual stains after long-term use. Inorganic coatings, while offering high hardness, generally suffer from insufficient flexibility and brittle cracking. Furthermore, the release of harmful substances such as volatile organic compounds (VOCs) and formaldehyde from coatings has heightened concern about environmental performance.

[0003] In recent years, the introduction of nanotechnology has opened up new avenues for improving the performance of coatings. By adding inorganic materials such as nano-silica and titanium dioxide, the hardness, wear resistance and UV resistance of the coating have been significantly improved. However, the dispersion stability of nanoparticles and their interfacial bonding with the organic resin matrix are still technical bottlenecks that restrict their widespread application. For example, nanoparticles are prone to reduce the density of the coating due to agglomeration, resulting in a decrease in anti-fouling performance; and the lack of compatibility between inorganic components and organic resins will weaken the mechanical strength and adhesion of the coating. In the existing technology, although the emulsion polymerization process has been optimized by adjusting the emulsifier system or introducing cross-linking monomers, there are still problems such as uneven latex particle size distribution and insufficient film density, which limit the further improvement of the comprehensive performance of the coating.

[0004] In terms of anti-fouling performance, existing technologies mostly rely on the introduction of low surface energy substances (such as silicone and fluorocarbon resin), but they are expensive and have poor compatibility with the base resin, and are prone to migration failure after long-term use. There are also related technologies that achieve anti-fouling by improving the hydrophobicity and oleophobicity of the coating, but they ignore the film density of the coating system, which can easily lead to a decrease in the mechanical properties of the coating. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides an antifouling high-hardness nano-ceramic paint and a preparation method thereof. The present application can simultaneously improve the antifouling performance and hardness of the ceramic paint by improving the film-forming density of the coating system.

[0006] In the first aspect, the present application provides an antifouling high-hardness nano-ceramic paint, which adopts the following technical solution: An antifouling high-hardness nano-porcelain paint comprises the following components in parts by weight: 90-120 parts of acrylate emulsion, 40-60 parts of nano-inorganic silicone resin, 5-10 parts of film-forming aid, 20-30 parts of titanium dioxide, 10-20 parts of filler, 0.5-2 parts of formaldehyde removal aid, 2-3 parts of dispersant, 0.5-1.5 parts of defoaming agent, 1-2 parts of thickener, and 10-20 parts of water; The acrylate emulsion has a solid content of 46-48% and is made from the following raw materials: a mixed monomer consisting of methyl methacrylate, n-butyl acrylate, isooctyl acrylate and methacrylic acid, a functional monomer consisting of triethoxysilane succinic anhydride, a crosslinking monomer consisting of diacetone acrylamide and dihydrazide adipic acid, an emulsifier, an initiator and water.

[0007] The acrylic emulsion polymer prepared in this application has methyl methacrylate as a hard monomer in the mixed monomers, which improves the rigidity, hardness and weather resistance of the polymer and adjusts the glass transition temperature of the polymer; n-butyl acrylate and isooctyl acrylate are used as soft monomers to give the polymer flexibility, elasticity and adhesion. Isooctyl acrylate is softer and more hydrophobic due to its long chain structure; methacrylic acid contains a carboxylic acid group, which enhances the stability of the emulsion, participates in the cross-linking reaction, and improves water resistance and mechanical strength. Among the functional monomers and cross-linking monomers, the anhydride group in triethoxysilane succinic anhydride can participate in the cross-linking reaction and enhance the stability of the emulsion. In addition, triethoxysilane succinic anhydride contains siloxy groups, which are very easy to react with inorganic substances, thereby improving the bonding force between the coating and the inorganic matrix. Diacetone acrylamide and dihydrazide adipic acid are a ketohydrazine cross-linking system. After film formation, covalent bonds are formed through the ketohydrazine reaction to achieve post-crosslinking, enhance the mechanical properties of the system, and density, thereby improving hardness and anti-fouling properties.

[0008] Further preferably, the acrylic emulsion is prepared by the following steps: Mix 80-90% of the emulsifier, functional monomer, cross-linking monomer and water, heat and stir, and add 80-90% of the mixed monomer to obtain a stable pre-emulsion; Mix 10-20% of the emulsifier with water, heat and stir, add 80-90% of the initiator and 10-20% of the mixed monomer, and complete the reaction to obtain a seed emulsion; 10-20% initiator and seed emulsion are added to the pre-emulsion, heated for reaction, and an acrylate emulsion is obtained.

[0009] By adjusting the order of adding each component, using an emulsifier to pre-emulsify most of the monomer raw materials, then emulsifying a small part of the raw monomers, and then mixing and reacting, the final acrylic emulsion has high film density, high hardness and high anti-fouling properties.

[0010] Further preferably, the emulsifier is composed of sodium salt of dioctyl sulfosuccinate and emulsifier MOA-7 in a weight ratio of 1:(0.5-1).

[0011] The emulsion film-forming process is a process of latex particles squeezing each other. The particle size of the latex particles has a significant impact on the film density. The smaller the particle size, the denser the film, and the better the anti-fouling properties of the coating. Sodium dioctyl sulfosuccinate and emulsifier MOA-7 are combined as emulsifiers to synergistically stabilize the emulsion. Sodium dioctyl sulfosuccinate acts through electrostatic repulsion, while emulsifier MOA-7 stabilizes the latex particles through steric hindrance, improving the particle size distribution and making the latex film denser.

[0012] More preferably, the weight proportions of the raw materials in the acrylic emulsion are: 50-100 parts of methyl methacrylate, 25-50 parts of n-butyl acrylate, 25-50 parts of isooctyl acrylate, 5-10 parts of methacrylic acid, 5-10 parts of triethoxysilane succinic anhydride, 1-3 parts of diacetone acrylamide, 1-3 parts of dihydrazide adipic acid, 5-10 parts of emulsifier, 1-3 parts of initiator, and 100 parts of water. More preferably, the titanium dioxide is nano-rutile titanium dioxide.

[0013] The use of nano-scale rutile titanium dioxide can improve the ability of porcelain paint to absorb ultraviolet light, increase the density of the paint film, and greatly improve the washability and mechanical strength of the paint.

[0014] More preferably, the filler is one or a combination of two of nano-silicon dioxide, talc, wollastonite, and mica powder.

[0015] Further preferably, the defoaming agent is one or a combination of two or more of a mineral oil-based defoaming agent, a silicone defoaming agent and a non-ionic defoaming agent.

[0016] More preferably, the thickener is one or a combination of two or more of hydroxyethyl cellulose, thickener TT-935, bentonite More preferably, the dispersant is one or a combination of two or more of acrylate, polyurethane, and sodium polyphosphate.

[0017] In a second aspect, the present application provides a method for preparing an antifouling high-hardness nano-ceramic paint, which adopts the following technical solution: A method for preparing an antifouling high-hardness nano-ceramic paint comprises the following steps: Add film-forming agent, dispersant, defoamer and thickener into water, stir and disperse evenly, continue to add acrylic emulsion and nano inorganic silicone resin, stir and disperse evenly, then add titanium dioxide and filler, stir and disperse evenly, finally add formaldehyde removal agent, stir and disperse evenly, and you have it.

[0018] In summary, this application has the following beneficial effects: Improved anti-fouling and self-cleaning properties: This application provides an acrylic emulsion prepared using a pre-emulsification and seed emulsion step-by-step polymerization process. The combination of sodium sulfosuccinate and MOA-7 as a composite emulsifier significantly improves the latex particle size distribution, resulting in a low porosity film and effective barrier to pollutant penetration. The introduction of nano-inorganic silicone resin and triethoxysilane succinic anhydride creates a low-surface-energy siloxane network on the coating surface, imparting hydrophobic and oleophobic properties. This makes stains difficult to adhere and easy to clean.

[0019] Synergistic Enhancement of High Hardness and Flexibility: Through the molecular structure design of the acrylic emulsion, a precise ratio of methyl methacrylate (hard monomer) to n-butyl acrylate and isooctyl acrylate (soft monomers), combined with a dual crosslinking system (ketohydrazine crosslinking + silane coupling), effectively balances the rigidity and flexibility of the coating. The hard monomer imparts high hardness and abrasion resistance to the coating, while the soft monomer improves adhesion and impact resistance. The dual crosslinking system further enhances the density of the coating, ultimately achieving a film hardness of over 3H.

[0020] Wide range of application scenarios: This vitrified paint combines high hardness, anti-fouling, environmental protection and decorative properties. It can be widely used in building exterior walls, interior walls, metal protection, wooden furniture and automotive accessories. It is especially suitable for children's room decoration and can deal with scenes where graffiti is likely to occur. DETAILED DESCRIPTION

[0021] The following describes the embodiments of the present application through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through different specific embodiments, and the details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present application.

[0022] Furthermore, it should be understood that the mention of one or more method steps in this application does not preclude the presence of other method steps before or after the combination of steps, or the insertion of other method steps between these explicitly mentioned steps, unless otherwise stated. Furthermore, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and is not intended to limit the order of the method steps or the scope of the application. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be considered within the scope of the application.

[0023] If the specific experimental conditions are not specified in the examples, they are usually based on conventional conditions in the field or conditions recommended by the reagent company; the materials, reagents, etc. used in the examples can be purchased through commercial channels unless otherwise specified.

[0024] The sources of some raw materials for this application are as follows: Nano inorganic silicone resin uses water-based nano inorganic silicone resin BS-518, purchased from Jinan Besto Polymer Chemical Technology Co., Ltd., and formaldehyde removal additive uses Rhodoline ® FS360 formaldehyde absorption aid was purchased from Nanjing Qinghai Trading Co., Ltd. Dioctyl sulfosuccinate sodium salt was purchased from Wuhan Kanos Technology Co., Ltd.; emulsifier MOA-7 was purchased from Nantong Dexin Chemical Co., Ltd.; nanosilica was purchased from Suzhou Qiuyi New Materials; and dimethyl silicone oil defoamer was purchased from Huangshan Qiangli Chemical Co., Ltd.

[0025] The triethoxysilane succinic anhydride in this application can be customized or prepared by itself. The preparation steps are as follows: 44.95g of allyltriethoxysilane and 19.61g of maleic anhydride are added to a 250mL flask as reaction raw materials, 0.47g of hydroquinone is added as an inhibitor, 5.77g of methanesulfonic acid is added as a catalyst, the reaction temperature is set to 180°C, and after reacting for 6h, it is cooled to room temperature, 100mL of petroleum ether and 10g of white clay are added, stirred for 10min and then filtered, the obtained filtrate is concentrated by rotary evaporation, and the residue is distilled under reduced pressure at 9mmHg and 290°C to obtain 47.22g of triethoxysilane succinic anhydride.

[0026] Preparation Example 1 Preparation of acrylic emulsion: Raw material composition: 50 parts of methyl methacrylate, 25 parts of n-butyl acrylate, 25 parts of isooctyl acrylate and 5 parts of methacrylic acid as a mixed monomer, 10 parts of triethoxysilane succinic anhydride as a functional monomer, 2 parts of diacetone acrylamide and 2 parts of dihydrazide adipic acid as a cross-linking monomer, a mixture of 4 parts of sodium salt of dioctyl sulfosuccinate and 2 parts of emulsifier MOA-7 as an emulsifier, 1 part of ammonium persulfate as an initiator, and 100 parts of water as a solvent.

[0027] Preparation steps: 80% of the emulsifier, functional monomer, and cross-linking monomer are mixed with water, heated to 50°C and stirred, and 80% of the mixed monomer is added at the same time, and the stirring is continued to obtain a stable pre-emulsion; 20% of the emulsifier is mixed with water, heated to 50°C and stirred, and 80% of the initiator and 20% of the mixed monomer are added successively, and the seed emulsion is obtained after the reaction is completed; 20% of the initiator and the seed emulsion are added to the pre-emulsion, heated to 95°C for reaction, and after the reaction is completed, an acrylate emulsion is obtained, and the solid content is detected to be 46.5%.

[0028] Preparation Example 2 Preparation of acrylic emulsion: The amount of raw materials and the preparation method are the same as those in Preparation Example 1. The difference from Preparation Example 1 is that the emulsifier is composed of a mixture of 3.5 parts of dioctyl sulfosuccinate sodium salt and 2.5 parts of emulsifier MOA-7.

[0029] Preparation Example 3 Preparation of acrylic emulsion: The amount of raw materials and the preparation method are the same as those in Preparation Example 1. The difference from Preparation Example 1 is that the emulsifier is composed of a mixture of 3 parts of sodium salt of dioctyl sulfosuccinate and 3 parts of emulsifier MOA-7.

[0030] Comparative Preparation Example 1 Preparation of acrylic emulsion: The amount of raw materials and the preparation method are the same as those in Preparation Example 1. The difference from Preparation Example 1 is that 6 parts of sodium salt of dioctyl sulfosuccinate are used as the emulsifier.

[0031] Comparative Preparation Example 2 Preparation of acrylic emulsion: The amount of raw materials and the preparation method are the same as those in Preparation Example 1. The difference from Preparation Example 1 is that 6 parts of emulsifier MOA-7 are used as the emulsifier.

[0032] Comparative Preparation Example 3 Preparation of acrylic emulsion: The amount of raw materials and the preparation method are the same as those in Preparation Example 1. The difference from Preparation Example 1 is that vinyltriethoxysilane is used instead of triethoxysilane succinic anhydride as the functional monomer to participate in the preparation of the acrylic ester emulsion.

[0033] Example Example 1 Preparation of antifouling high hardness nano-ceramic paint: The acrylic emulsion obtained in Preparation Example 1 and the water-based nano-inorganic silicone resin BS-518 were used as the film-forming system, with dodecyl alcohol ester as a film-forming aid, nano-silica as a filler, dimethyl silicone oil as a defoamer, sodium hexametaphosphate as a dispersant, and hydroxyethyl cellulose as a thickener to prepare a porcelain paint. The specific amounts of the raw materials used are shown in Table 1.

[0034] Preparation steps: add film-forming agent, dispersant, defoaming agent and thickener into water, stir and disperse evenly, continue to add acrylic emulsion and nano inorganic silicone resin, stir and disperse evenly, then add titanium dioxide and filler, stir and disperse evenly, finally add formaldehyde removal agent, stir and disperse evenly, and the product is obtained.

[0035] Example 2-3 Preparation of antifouling high-hardness nano-ceramic paint: The raw material amounts are shown in Table 1, and the preparation method is the same as in Example 1.

[0036] Table 1 Amounts of raw materials used in Examples 1-3 Example 4 Preparation of antifouling high-hardness nano-ceramic paint: The raw material dosage and preparation method are the same as those in Example 1. The difference from Example 1 is that the acrylic emulsion is prepared in Example 2.

[0037] Example 5 Preparation of antifouling high-hardness nano-ceramic paint: The raw material dosage and preparation method are the same as those in Example 1. The difference from Example 1 is that the acrylic emulsion is prepared in Example 3.

[0038] Comparative Example Comparative Example 1 Preparation of nano-ceramic paint: The raw material dosage and preparation method are the same as those in Example 1. The difference from Example 1 is that the acrylic emulsion is prepared by Comparative Preparation Example 1.

[0039] Comparative Example 2 Preparation of nano-ceramic paint: The raw material dosage and preparation method are the same as those in Example 1. The difference from Example 1 is that the acrylic emulsion is prepared by Comparative Preparation Example 2.

[0040] Comparative Example 3 Preparation of nano-ceramic paint: The raw material dosage and preparation method are the same as those in Example 1. The difference from Example 1 is that the acrylic emulsion is prepared by Comparative Preparation Example 3.

[0041] Comparative Example 4 Preparation of nano-ceramic paint: The raw material dosage and preparation method are the same as those in Example 1. The difference from Example 1 is that the acrylic emulsion is purchased from Dow Chemical, model number is PRIMAL TR407.

[0042] Performance testing The porcelain paints prepared in Examples 1-5 and Comparative Examples 1-4 were subjected to comparative tests on stain resistance, scrub resistance, and hardness. The specific test standards are as follows. The test results are shown in Table 2.

[0043] Stain resistance: Film making, curing and scrubbing are carried out according to GB / T 9780-2013 "Test method for stain resistance of architectural coatings", and the comprehensive stain resistance ΔE is used as the evaluation index, ΔE= , where ΔL, Δa, and Δb represent the differences in L (brightness value), a (red-green value), and b (yellow-blue value) before and after wiping, respectively. The smaller ΔE is, the closer the color of the stain is to the blank coating without coloring, that is, the stronger the stain resistance.

[0044] Washability: Tested in accordance with GB / T 9756-2018 Synthetic resin emulsion interior wall coatings.

[0045] Hardness: Tested according to GB / T 6739-2022 Paints and varnishes pencil method for determining paint film hardness Table 2 Test results As can be seen from Table 2, the porcelain paint prepared in this application has excellent stain resistance, scrub resistance, and high hardness.

[0046] Comparing the test results of Example 1 and Comparative Examples 1-2, it can be seen that the selection and dosage of the emulsifier have a great influence on the performance of the final coating. The acrylic emulsion prepared by using sodium salt of dioctyl sulfosuccinate and MOA-7 as a compound emulsifier has high anti-fouling performance and hardness. This is because the emulsifier mainly controls the particle size and distribution of the latex particles. The compound emulsifier of the present application can obtain an emulsion with a uniform particle size distribution, thereby improving the film density.

[0047] Comparing the test results of Example 1 and Comparative Example 3, it can be seen that the use of triethoxysilane succinic anhydride as a functional monomer is better than the use of vinyl triethoxy. This is because the anhydride in triethoxysuccinic anhydride can participate in the emulsion cross-linking reaction and the later coating film-forming cross-linking reaction, and the siloxane group is easy to react with inorganic substances, thereby improving the bonding strength. In addition, the triethoxysilane succinic anhydride of the present application is prepared from allyl triethoxysilane and maleic anhydride, and the chain length is relatively longer. Therefore, the toughness of the obtained coating is also better than that of the vinyl silane coupling agent. The coatings prepared by the two are separately tested for impact resistance in the present application. The test results show that the impact resistance is respectively 42 cm for Example 1 and 31 cm for Comparative Example 3. It can be seen that the coating prepared in the present application has higher toughness.

[0048] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention. Any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An antifouling high-hardness nano-ceramic paint, characterized in that: The invention comprises the following components in parts by weight: 90-120 parts of acrylic emulsion, 40-60 parts of nano inorganic silicone resin, 5-10 parts of film-forming aid, 20-30 parts of titanium dioxide, 10-20 parts of filler, 0.5-2 parts of formaldehyde removal aid, 2-3 parts of dispersant, 0.5-1.5 parts of defoaming agent, 1-2 parts of thickener, and 10-20 parts of water; The acrylate emulsion has a solid content of 46-48% and is made from the following raw materials: a mixed monomer consisting of methyl methacrylate, n-butyl acrylate, isooctyl acrylate and methacrylic acid, a functional monomer consisting of triethoxysilane succinic anhydride, a crosslinking monomer consisting of diacetone acrylamide and dihydrazide adipic acid, an emulsifier, an initiator and water.

2. The antifouling high-hardness nano-ceramic paint according to claim 1, characterized in that: The acrylic emulsion is prepared by the following steps: Mix 80-90% of the emulsifier, functional monomer, cross-linking monomer and water, heat and stir, and add 80-90% of the mixed monomer to obtain a stable pre-emulsion; Mix 10-20% of the emulsifier with water, heat and stir, add 80-90% of the initiator and 10-20% of the mixed monomer, and complete the reaction to obtain a seed emulsion; 10-20% initiator and seed emulsion are added to the pre-emulsion, heated for reaction, and an acrylate emulsion is obtained.

3. The antifouling high-hardness nano-ceramic paint according to claim 2, characterized in that: The emulsifier is composed of sodium salt of dioctyl sulfosuccinate and emulsifier MOA-7 in a weight ratio of 1:(0.5-1).

4. The antifouling high-hardness nano-ceramic paint according to claim 3, characterized in that: The weight proportions of the raw materials in the acrylic ester emulsion are: 50-100 parts of methyl methacrylate, 25-50 parts of n-butyl acrylate, 25-50 parts of isooctyl acrylate, 5-10 parts of methacrylic acid, 5-10 parts of triethoxysilane succinic anhydride, 1-3 parts of diacetone acrylamide, 1-3 parts of dihydrazide adipic acid, 5-10 parts of emulsifier, 1-3 parts of initiator and 100 parts of water.

5. The antifouling high-hardness nano-ceramic paint according to claim 1, characterized in that: The titanium dioxide is nano-rutile titanium dioxide.

6. The antifouling high-hardness nano-ceramic paint according to claim 1, characterized in that: The filler is one or a combination of two of nano silicon dioxide, talc powder, wollastonite and mica powder.

7. The antifouling high-hardness nano-ceramic paint according to claim 1, characterized in that: The dispersant is one or a combination of two or more of acrylate, polyurethane and sodium polyphosphate.

8. The antifouling high-hardness nano-ceramic paint according to claim 1, characterized in that: The defoaming agent is one or a combination of two or more of a mineral oil-based defoaming agent, a silicone defoaming agent and a non-ionic defoaming agent.

9. The antifouling high-hardness nano-ceramic paint according to claim 1, characterized in that: The thickener is one or a combination of two or more of hydroxyethyl cellulose, thickener TT-935 and bentonite.

10. A method for preparing the antifouling high-hardness nano-ceramic paint according to any one of claims 1 to 9, characterized in that: The method comprises the following preparation steps: Add film-forming agent, dispersant, defoamer and thickener into water, stir and disperse evenly, continue to add acrylic emulsion and nano inorganic silicone resin, stir and disperse evenly, then add titanium dioxide and filler, stir and disperse evenly, finally add formaldehyde removal agent, stir and disperse evenly, and you have it.

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