Saline-alkali flooding resistant reaction type transparent primer and preparation method thereof

Abstract

The invention relates to salt and alkali flooding resistant reaction type transparent primer. The primer comprises the following raw material components in parts by weight: 30-50 parts of a base material emulsion, 4-10 parts of a multifunctional silane coupling agent, 5-15 parts of a reactive monomer, 2-4 parts of a cross-linking agent, 2-6 parts of a nano reinforcing material, 2-5 parts of an auxiliary agent and 10-55 parts of deionized water, the reaction monomer comprises a phosphate group-containing monomer and a carboxylic acid group-containing monomer. The phosphate group and the carboxylic acid group in the reaction monomer can form stable coordinate bonds and ionic bonds with ions such as Ca < 2 + > and Mg < 2 + > in a base layer; meanwhile, silicon hydroxyl formed by hydrolyzing the multifunctional silane coupling agent can be subjected to condensation reaction with silicon hydroxyl on the surface of the base layer to form a firm Si-O-Si covalent bond. The three chemical bonds are synergistic, a compact chemical bonding anchoring layer can be constructed on an interface, soluble salt and alkali ions are fixed, precipitation of the soluble salt and alkali ions is fundamentally inhibited, and the binding force of the primer and a base layer is remarkably enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of architectural coatings, in particular to an anti-salt-alkali reaction type transparent primer and a preparation method thereof. BACKGROUND

[0002] In the field of building exterior wall decoration, architectural coatings mainly include latex paint and stone-like paint (such as real stone paint, texture paint and multi-color paint). Stone-like paint has more thick coating than latex paint, and puts forward stricter standard requirements for the sealing and reinforcement effect of the base layer. The traditional stone-like coating construction process usually includes putty layer, transparent primer, same-color intermediate coating, stone-like paint main material and topcoat. Among them, the transparent primer plays a key role in the system, and the main functions include: (1) sealing the base layer to prevent water penetration and alkali substance precipitation; (2) enhancing the adhesion of the intermediate coating to the base layer.

[0003] At present, the common transparent primer on the market is mainly acrylic, silicone-acrylic or epoxy emulsion system, which mainly forms a sealing layer through physical film formation to inhibit the precipitation of base layer alkali substances (such as Ca(OH)2, NaOH, KOH, etc.). However, this physical sealing has the following defects: (1) the sealing effect is not complete, and salt precipitation and salt precipitation may still occur after long-term use; (2) the combination with the base layer is mainly physical adsorption, and the adhesion is limited; (3) the adhesion between the intermediate coating and the base layer is insufficient, and interlayer peeling may occur.

[0004] In order to improve the above problems, the prior art such as CN113969086A discloses an interior wall alkali-resistant primer, which is compounded by acrylic copolymer emulsion and nano-silica sol, and supplemented by modified rosin resin alkali-resistant agent to improve the sealing and alkali resistance effect. However, the alkali resistance mechanism of this scheme still focuses on physical sealing; at the same time, it is mainly aimed at the interior wall environment, and there are deficiencies in terms of ultraviolet aging resistance and adhesion.

[0005] Therefore, it is necessary to further improve the existing transparent primer to improve its sealing effect on the base layer alkali substances and enhance its adhesion to the base layer and the intermediate coating. SUMMARY

[0006] In order to solve the above technical problems, the present application provides an anti-salt-alkali reaction type transparent primer and a preparation method thereof.

[0007] The technical scheme adopted by the present application is: The present application provides an anti-salt-alkali reaction type transparent primer, and the raw material components include, by weight: 30-50 parts of base emulsion, 4-10 parts of multifunctional silane coupling agent, 5-15 parts of reaction monomer, 2-4 parts of crosslinking agent, 2-6 parts of nano-enhancing material, 2-5 parts of auxiliary agent, and 10-55 parts of deionized water; The reaction monomers include monomers containing phosphate ester groups and monomers containing carboxylic acid groups.

[0008] This invention proposes an anti-efflorescence reactive transparent primer, which, through the phosphate ester and carboxylic acid groups in the reactive monomers, can react with Ca in the substrate. 2+ Mg 2+ Plasma forms stable coordination and ionic bonds; simultaneously, the silanol groups formed by the hydrolysis of multifunctional silane coupling agents can undergo condensation reactions with the silanol groups on the substrate surface, forming strong Si-O-Si covalent bonds. These three types of chemical bonds work synergistically to construct a dense "chemical bond anchoring layer" at the interface, fixing soluble salt and alkali ions, fundamentally inhibiting their precipitation, and significantly enhancing the adhesion between the primer and the substrate.

[0009] Preferably, the weight ratio of the phosphate-containing monomer to the carboxylic acid-containing monomer is 3~8:2~7.

[0010] Preferably, the phosphate-containing monomer is 2-hydroxyethyl methacrylate phosphate, and the carboxylic acid-containing monomer is methacrylic acid.

[0011] Preferably, the base emulsion comprises 20-30 parts by weight of silane-modified polyurethane emulsion and 10-20 parts of epoxy-based siloxane oligomer.

[0012] Preferably, the multifunctional silane coupling agent includes epoxy silane coupling agents, amino silane coupling agents, and vinyl silane coupling agents.

[0013] Preferably, the weight ratio of the epoxy silane coupling agent, the amino silane coupling agent, and the vinyl silane coupling agent is 2~4:1~3:1~3.

[0014] Preferably, the epoxy silane coupling agent is γ-glycidoxypropyltrimethoxysilane, the amino silane coupling agent is N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and the vinyl silane coupling agent is vinyltriethoxysilane.

[0015] Preferably, the nano-reinforcing material includes nano-silica sol and nano-zinc oxide; The particle size of the nano-silica sol is 10~30nm; The particle size of the nano zinc oxide is 20~50nm.

[0016] Preferably, the crosslinking agent includes aziridine crosslinking agents and carbodiimide crosslinking agents; The additives are selected from one or a combination of two or more of the following: wetting agents, defoamers, leveling agents, ultraviolet absorbers, and light stabilizers.

[0017] Another aspect of the present application provides a preparation method of the above-mentioned transparent primer against salt-alkali reaction, comprising the following steps: S1, dispersing the nano-enhanced material in deionized water to form a dispersion; S2, pre-reacting the base emulsion, multifunctional silane coupling agent and reaction monomer at 40-50°C to form a premix; S3, adding the dispersion to the premix, and then adding a crosslinking agent and an additive, and mixing and stirring uniformly. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The upper part represents the transparent primer layer of the present application, which contains a plurality of active functional groups; the lower part represents the base layer, which is rich in Ca 2+ , Mg 2+ and other salt-alkali substances; and the interface region between the two is the region where multiple chemical reactions occur. DETAILED DESCRIPTION

[0019] In order to better understand the above technical solutions, the exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer, more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0020] One aspect of the present application provides a transparent primer against salt-alkali reaction, the raw material components including, by weight: 30-50 parts of base emulsion, 4-10 parts of multifunctional silane coupling agent, 5-15 parts of reaction monomer, 2-4 parts of crosslinking agent, 2-6 parts of nano-enhanced material, 2-5 parts of additive, and 10-55 parts of deionized water; The reaction monomer includes phosphate group-containing monomer and carboxylic acid group-containing monomer.

[0021] As shown in Figure 1 , unlike traditional physical sealing, the present application achieves active bonding and anchoring of the base layer through multiple chemical reactions, thereby fundamentally suppressing salt-alkali and significantly improving adhesion: (1) coordination bond and ionic bond fix alkali ions: the phosphate groups (-PO(OH)2) in the reaction monomer can form stable calcium phosphate coordination bonds with Ca 2+ in the base layer; at the same time, the carboxylic acid groups (-COOH) can form stable calcium carboxylate ionic bonds with Ca 2+ , Mg 2+The two kinds of chemical bonds can sufficiently fix the free soluble saline alkali ions in the base layer and prevent them from migrating to the surface from the source. (2) Covalent bond realizes interface grafting: the alkoxy groups (-Si(OR) 3, R represents alkyl) of the multifunctional silane coupling agent are hydrolyzed to generate silicon hydroxyl groups (-Si-OH), which further condense with the silicon hydroxyl groups on the surface of the base layer to form firm Si-O-Si covalent bonds, so that the primer is "chemically grafted" to the base layer. Thus, the coordination bond, the ionic bond and the covalent bond are coordinated to build a dense "chemical bonding anchoring layer" at the interface, realize the transformation from passive physical sealing to active chemical anchoring, and provide long-term and stable interfacial bonding force.

[0022] In the preferred embodiment of the present application, the weight ratio of the phosphate group-containing monomer and the carboxylic acid group-containing monomer is 3-8:2-7. For example, the weight ratio of the phosphate group-containing monomer and the carboxylic acid group-containing monomer can be 3:2, 3:7, 4:3, 5:4, 6:5, 7:6, 8:2, 8:7, etc.

[0023] In the preferred embodiment of the present application, the phosphate group-containing monomer is 2-hydroxyethyl methacrylate phosphate, and the carboxylic acid group-containing monomer is methacrylic acid. The present application selects 2-hydroxyethyl methacrylate phosphate as the phosphate group-containing monomer, which contains phosphate groups that can form coordination bonds with Ca 2+ , Mg 2+ , etc. to form ionic bonds, thereby providing long-term and deep anchoring. The present application selects methacrylic acid as the carboxylic acid group-containing monomer, which contains carboxylic acid groups with high reactivity that can quickly form ionic bonds with Ca 2+ , Mg 2+ , etc. to achieve immediate and rapid fixation. The two kinds of monomers are coordinated to not only achieve efficient and long-term fixation of soluble saline alkali ions, but also promote a significant increase in adhesion to the base layer. In addition, both of them are acrylic derivatives, which have excellent compatibility and copolymerization with the base emulsion system of the present application, so that the above-mentioned reaction monomers can be stably and uniformly distributed in the paint film, thereby effectively realizing active chemical bonding.

[0024] In the preferred embodiment of the present application, the base emulsion includes 20-30 parts of silane-modified polyurethane emulsion and 10-20 parts of epoxy siloxane oligomer by weight. The present application selects the above-mentioned amount of silane-modified polyurethane emulsion and epoxy siloxane oligomer to be compounded as the base emulsion, which not only has good compatibility with the reaction monomers and the multifunctional silane coupling agent to ensure film-forming properties, but also the epoxy groups of the epoxy siloxane oligomer can react with active groups (such as amino groups and hydroxyl groups) in the intermediate coating resin (such as acrylic and silicone-acrylic emulsion) to form chemical bonds, thereby strengthening the interlayer adhesion between the primer and the intermediate coating.

[0025] In the preferred embodiments of the present application, the multifunctional silane coupling agent includes an epoxy silane coupling agent, an amino silane coupling agent and a vinyl silane coupling agent. The multifunctional silane coupling agent of the above-mentioned type is screened in the present application to achieve the dual chemical bridging of the "base layer-primer-intermediate coating" in cooperation. On the one hand, the silicon hydroxyl generated after the hydrolysis of the alkoxyl contained therein can form a Si-O-Si covalent network with the surface of the base layer, thereby significantly enhancing the interfacial bonding force between the primer and the base layer; on the other hand, the epoxy group and the amino group contained therein can chemically react with the corresponding groups (such as hydroxyl group and amino group) of the intermediate coating resin, or form strong hydrogen bonds and physical interpenetrating networks, thereby greatly improving the interlayer adhesion between the primer and the intermediate coating.

[0026] In the preferred embodiments of the present application, the weight ratio of the epoxy silane coupling agent, the amino silane coupling agent and the vinyl silane coupling agent is 2-4:1-3:1-3. For example, the weight ratio of the epoxy silane coupling agent, the amino silane coupling agent and the vinyl silane coupling agent can be 2:1:1, 2:2:2, 3:1:2, 3:2:1, 3:2:2, 4:1:3, 4:3:1, 4:3:3, etc.

[0027] In the preferred embodiments of the present application, the epoxy silane coupling agent is γ-glycidoxypropyltrimethoxysilane, the amino silane coupling agent is N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and the vinyl silane coupling agent is vinyltriethoxysilane. The γ-glycidoxypropyltrimethoxysilane, the N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and the vinyltriethoxysilane are compounded in the present application to efficiently construct a functional synergistic reinforcing system, thereby endowing the primer with excellent interlayer adhesion with the base layer and the intermediate coating.

[0028] In the preferred embodiments of the present application, the nano-enhanced material includes nano-silica sol and nano-zinc oxide; The particle size of the nano-silica sol is 10-30 nm; The particle size of the nano-zinc oxide is 20-50 nm.

[0029] In this invention, the two components mentioned above are selected as nano-reinforcing materials. The SiO2 particles of the nano-silica sol effectively fill the microscopic pores and defects between polymer molecular chains, making the paint film structure denser and ensuring the most basic sealing effect of the transparent primer. For example, the particle size of the nano-silica sol can be 10nm, 15nm, 20nm, 25nm, 30nm, etc. Nano-zinc oxide has extremely strong absorption and dispersion capabilities for ultraviolet light, effectively protecting the aforementioned chemical bonds from degradation by ultraviolet light, thereby improving the lifespan of the building coating system. Simultaneously, the released zinc ions have a certain antibacterial and antifungal effect, achieving zero-formaldehyde antibacterial and antifungal protection. For example, the particle size of the nano-zinc oxide can be 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, etc. Furthermore, this invention does not particularly limit the amount of nano-silica sol and nano-zinc oxide used. For example, by weight, the amount of each nano-silica sol and nano-zinc oxide can be independently 1 to 3 parts.

[0030] In a preferred embodiment of the present invention, the crosslinking agent includes aziridine crosslinking agents and carbodiimide crosslinking agents; The additives are selected from one or a combination of two or more of the following: wetting agents, defoamers, leveling agents, ultraviolet absorbers, and light stabilizers.

[0031] In this invention, the selection of aziridine-based crosslinking agents and carbodiimide-based crosslinking agents is beneficial for the rapid formation of a stable and dense three-dimensional network of the paint film. For example, by weight, the amount of each of the aziridine-based and carbodiimide-based crosslinking agents can be 1 to 2 parts. Furthermore, this invention appropriately introduces additives to improve the quality of the paint film and the application performance of the coating. Conventional additives in the art can be used, and they can be directly purchased and used from the market without any particular restrictions. For example, by weight, the wetting agent can be a nonionic polyether siloxane (0.4 to 0.7 parts), the defoamer can be a mineral oil (0.4 to 0.8 parts), the leveling agent can be a polyurethane (0.2 to 0.5 parts), the ultraviolet absorber can be a benzotriazole (0.5 to 1.5 parts), and the light stabilizer can be a hindered amine (0.5 to 1.5 parts).

[0032] Another aspect of the present invention provides a method for preparing the above-mentioned anti-efflorescence transparent primer, comprising the following steps: S1. Disperse the nano-reinforced material in deionized water to form a dispersion; S2. The base emulsion, multifunctional silane coupling agent and reactive monomer are pre-reacted at 40~50℃ to form a premix; S3. Add the dispersion to the premix, then add the crosslinking agent and additives, and mix thoroughly.

[0033] This invention pre-reacts the base emulsion, multifunctional silane coupling agent and reactive monomer at 40~50℃, which is beneficial for more efficient and uniform reaction with the base layer during subsequent construction.

[0034] The sources of the raw material components involved in the following examples and comparative examples are as follows: Silane-modified polyurethane emulsion: Aikema (8081) Epoxysiloxane oligomers: Shin-Etsu (KR-516) γ-glycidyl etheroxypropyltrimethoxysilane: Huanzheng Chemical (KH-560) Vinyltriethoxysilane: Heyuan Chemical (A-151) N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane: Shanghe Chemical (KH-792) 2-Hydroxyethyl methacrylate phosphate: Evonik (HEMA-P) Methacrylic acid: Corward (MAA) Aziridine crosslinking agent: Xingrui Chemical (SaC-100) Carbodiimide crosslinking agent: Xirun Chemical (XR-201) Nano silica sol: Fangyu Chemical (JC-300) Nano Zinc Oxide: Wangjiang (Nano Zinc Oxide) Wetting agent (nonionic polyether siloxane): Evonik (5840) Defoamer (mineral oil type): BASF (MO 2134) Leveling agent (polyurethane): Idico (UH-420) UV absorber (benzotriazole): BASF (Tinuvin P) Light stabilizer (hindered amine): Rianlon (UV292) Example 1 A transparent primer resistant to efflorescence, comprising the following raw material components by weight: The composition includes: 30 parts base emulsion (20 parts silane-modified polyurethane emulsion, 10 parts epoxy siloxane oligomer), 4 parts multifunctional silane coupling agent (2 parts γ-glycidyl etheroxypropyltrimethoxysilane, 1 part N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 1 part vinyltriethoxysilane), 5 parts reactive monomer (3 parts 2-hydroxyethyl methacrylate phosphate, 2 parts methacrylic acid), 2 parts crosslinking agent (1 part aziridine crosslinking agent, 1 part carbodiimide crosslinking agent), 2 parts nano-reinforcing material (1 part nano silica sol, 1 part nano zinc oxide), 2 parts additives (0.4 parts wetting agent, 0.4 parts defoamer, 0.2 parts leveling agent, 0.5 parts ultraviolet absorber, 0.5 parts light stabilizer), and 55 parts deionized water.

[0035] It is prepared by the following method, including the following steps: S1. Disperse the nano-reinforced material in deionized water to form a dispersion; S2. The base emulsion, multifunctional silane coupling agent and reactive monomer are pre-reacted at 40°C to form a premix; S3. Add the dispersion to the premix, then add the crosslinking agent and additives, and mix thoroughly.

[0036] Example 2 A transparent primer resistant to efflorescence, comprising the following raw material components by weight: The composition includes: 40 parts base emulsion (25 parts silane-modified polyurethane emulsion, 15 parts epoxy siloxane oligomer), 7 parts multifunctional silane coupling agent (3 parts γ-glycidoxypropyltrimethoxysilane, 2 parts N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, 2 parts vinyltriethoxysilane), 9 parts reactive monomer (5 parts 2-hydroxyethyl methacrylate phosphate, 4 parts methacrylic acid), 3 parts crosslinking agent (1.5 parts aziridine crosslinking agent, 1.5 parts carbodiimide crosslinking agent), 4 parts nano-reinforcing material (2 parts nano silica sol, 2 parts nano zinc oxide), 3.5 parts additives (0.6 parts wetting agent, 0.6 parts defoamer, 0.3 parts leveling agent, 1 part ultraviolet absorber, 1 part light stabilizer), and 33.5 parts deionized water.

[0037] It is prepared by the following method, including the following steps: S1. Disperse the nano-reinforced material in deionized water to form a dispersion; S2. The base emulsion, multifunctional silane coupling agent and reactive monomer are pre-reacted at 45°C to form a premix; S3. Add the dispersion to the premix, then add the crosslinking agent and additives, and mix thoroughly.

[0038] Example 3 A transparent primer resistant to efflorescence, comprising the following raw material components by weight: The base emulsion consists of 50 parts (30 parts of silane-modified polyurethane emulsion and 20 parts of epoxy siloxane oligomer), 10 parts of multifunctional silane coupling agent (4 parts of γ-glycidyl etheroxypropyltrimethoxysilane, 3 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and 3 parts of vinyltriethoxysilane), 15 parts of reactive monomer (8 parts of 2-hydroxyethyl methacrylate phosphate and 7 parts of methacrylic acid), 4 parts of crosslinking agent (2 parts of aziridine crosslinking agent and 2 parts of carbodiimide crosslinking agent), 6 parts of nano-reinforcing material (3 parts of nano-silica sol and 3 parts of nano-zinc oxide), 5 parts of additives (0.7 parts of wetting agent, 0.8 parts of defoamer, 0.5 parts of leveling agent, 1.5 parts of ultraviolet absorber, and 1.5 parts of light stabilizer), and 10 parts of deionized water.

[0039] It is prepared by the following method, including the following steps: S1. Disperse the nano-reinforced material in deionized water to form a dispersion; S2. The base emulsion, multifunctional silane coupling agent and reactive monomer are pre-reacted at 50°C to form a premix; S3. Add the dispersion to the premix, then add the crosslinking agent and additives, and mix thoroughly.

[0040] Comparative Example 1 The difference between this comparative example and Example 2 is that no reactant monomer is added, and the weight percentage of deionized water is increased accordingly. The remaining steps remain unchanged.

[0041] Comparative Example 2 The difference between this comparative example and Example 2 is that no multifunctional silane coupling agent is added, and the weight percentage of deionized water is increased accordingly. The remaining steps remain unchanged.

[0042] Comparative Example 3 The difference between this comparative example and Example 2 is that no nano-reinforcing material is added, and the weight percentage of deionized water is increased accordingly. The remaining steps remain unchanged.

[0043] Comparative Example 4 The difference between this comparative example and Example 2 is that an equal amount of ordinary acrylic emulsion is used to replace the base emulsion, and 6 wt% of a film-forming aid is added to the emulsion. The weight percentage of deionized water is reduced accordingly. The remaining steps remain unchanged.

[0044] Comparative Example 5 Commercially available standard closed transparent primer.

[0045] The samples obtained from the above embodiments and comparative examples were subjected to performance tests, and the results are recorded in Table 1.

[0046] The testing method is as follows: 1) The performance of the above samples shall be performed in accordance with the standard JG / T 210-2018 "Primers for Interior and Exterior Walls of Buildings"; the limits of hazardous substances shall be performed in accordance with the standard GB 30981.1-2025 "Limits of Hazardous Substances in Coatings Part 1: Architectural Coatings".

[0047] 2) Test indicators for artificial weathering resistance were conducted according to GB / T 1865-2009 "Artificial Weathering and Artificial Radiation Exposure to Filtered Xenon Arc Radiation for Paints and Varnishes". Xenon lamp aging tests were performed using an ATLAS Ci5000 xenon lamp artificial weathering tester. The test conditions were: irradiance (340nm) 0.51W / m². 2 Relative humidity (40~60)%; black mark temperature (65±2)℃; rainfall cycle 18min / 102min (spraying time / no spraying time). An 800-hour xenon lamp accelerated aging test was conducted to examine the weather resistance of the samples.

[0048] 3) For the above samples, the color difference change of the coating film was measured using a CR10 colorimeter from KONICA MOINLTA, Japan, according to ISO 7724-3:1984 "Colorimetric method for paints and varnishes - Part 3: Calculation of color difference". The degree of color change after aging was rated as excellent, good, medium and poor according to GB / T 1766-2008 "Rating method for aging of paint and varnish coatings".

[0049] Table 1

[0050] As shown in Table 1, the anti-alkali reactive transparent primers prepared in each embodiment of the present invention exhibit excellent properties. Compared with Comparative Example 1, which lacks reactive monomers, its film exhibits a sharp decline in alkali resistance, tear resistance, and adhesion, confirming that the active chemical bonding provided by the phosphate ester / carboxylic acid reactive monomers of the present invention is fundamental to alkali resistance, superior to traditional physical sealing. Compared with Comparative Example 2, which lacks multifunctional silane coupling agents, its adhesion and water resistance are significantly deteriorated, revealing that Si-O-Si covalent bonding is a crucial link in strengthening interfacial bonding. Compared with Comparative Example 3, which lacks nano-reinforcing materials, its film exhibits better density (poor water permeability) and UV aging resistance (ΔE). Both the coating strength and adhesion decreased, indicating that nano-reinforcing materials are indispensable in improving the density of the coating film, enhancing UV shielding, and maintaining long-term stability. Compared with Comparative Example 4, which uses ordinary acrylic emulsion, the performance of the coating film decreased sharply due to compatibility issues with other functional components. In addition, additional film-forming aids were required, resulting in the product exceeding the limits for harmful substances and failing to meet environmental protection standards. Compared with Comparative Example 5, which uses commercially available conventional transparent primer, the embodiments of the present invention have significant advantages in core properties such as resistance to alkali bloom, adhesion, and aging resistance.

[0051] In summary, the anti-efflorescence transparent primer of the present invention has the following advantages: (1) Through multiple chemical reactions (coordinate bond, ionic bond, covalent bond) between the reactive monomer and the multifunctional silane coupling agent, it actively bonds with the substrate, fundamentally solving the efflorescence problem, and simultaneously greatly enhancing the adhesion between the primer and the substrate; (2) The active functional groups contained in the multifunctional silane coupling agent and the base emulsion can react chemically with the intermediate coating resin, form hydrogen bonds or form a physical interpenetrating network, thereby significantly improving the interlayer bonding force. (3) Nano-reinforcing materials enhance the coating adhesion and durability by physically filling and densifying and functionalizing with UV protection / antibacterial properties. (4) The product has extremely low VOC and SVOC content and contains no formaldehyde, fully meeting the stringent requirements of green building coatings.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A transparent primer against a general salt and alkali reaction, characterized by, The raw material components include, by weight parts: 30-50 parts of base emulsion, 4-10 parts of multifunctional silane coupling agent, 5-15 parts of reaction monomer, 2-4 parts of crosslinking agent, 2-6 parts of nano-enhancing material, 2-5 parts of auxiliary agent, and 10-55 parts of deionized water; The reaction monomer includes phosphate group-containing monomer and carboxylic acid group-containing monomer.

2. The anti-all-round salt reaction type transparent primer according to claim 1, wherein The weight ratio of the phosphate group-containing monomer to the carboxylic acid group-containing monomer is 3-8:2-7.

3. The anti-all-round salt reaction type transparent primer according to claim 1, wherein The phosphate group-containing monomer is 2-hydroxyethyl methacrylate phosphate, and the carboxylic acid group-containing monomer is methacrylic acid.

4. The anti-all-round salt reaction type transparent primer according to claim 1, wherein The base emulsion includes, by weight parts, 20-30 parts of silane-modified polyurethane emulsion and 10-20 parts of epoxy-siloxane oligomer.

5. The anti-all-round salt reaction type transparent primer according to claim 1, wherein The multifunctional silane coupling agent includes epoxy-silane coupling agent, amino-silane coupling agent, and vinyl-silane coupling agent.

6. The anti-all-round salt reaction type transparent primer according to claim 5, wherein The weight ratio of the epoxy-silane coupling agent, the amino-silane coupling agent, and the vinyl-silane coupling agent is 2-4:1-3:1-3.

7. The anti-all-round salt reaction type transparent primer according to claim 5, wherein The epoxy-silane coupling agent is γ-glycidoxypropyltrimethoxysilane, the amino-silane coupling agent is N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and the vinyl-silane coupling agent is vinyltriethoxysilane.

8. The anti-all-round salt reaction type transparent primer according to claim 1, wherein The nano-enhancing material includes nano-silica sol and nano-zinc oxide; The particle size of the nano-silica sol is 10-30 nm; The particle size of the nano-zinc oxide is 20-50 nm.

9. The anti-all-round salt reaction type transparent primer according to claim 1, wherein The crosslinking agent includes aziridine crosslinking agent and carbodiimide crosslinking agent. The auxiliary agent is selected from one or a combination of two or more of wetting agent, defoaming agent, leveling agent, ultraviolet absorber, and light stabilizer.

10. A method of preparing the anti-all-round alkali reaction type transparent primer according to claim 1, characterized by, The method includes the following steps: S1, dispersing the nano-enhancing material in deionized water to form a dispersion; S2, pre-reacting the base emulsion, the multifunctional silane coupling agent, and the reaction monomer at 40-50°C to form a premix; S3, adding the dispersion to the premix, and then adding the crosslinking agent and the auxiliary agent and mixing and stirring uniformly.

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