High-elasticity wear-resistant waterproof coating and preparation method thereof

Abstract

The invention relates to the technical field of coatings, and discloses a high-elasticity wear-resistant waterproof coating and a preparation method of the high-elasticity wear-resistant waterproof coating. Then three functional coatings are prepared in sequence: a) a basic bonding layer: mixing a polyurethane emulsion, modified amino resin and a defoaming agent with a flatting agent and silica fume powder, and shearing and dispersing at a high speed for later use; b) preparing an elastic wear-resistant layer: pre-emulsifying and stirring elastic modified powder, polyether type acrylic emulsion, hollow glass beads, zirconium silicate particles and a water-based rheology modifier for later use; c) a waterproof sealing layer: performing ultrasonic emulsification mixing on a fluorocarbon emulsion, a hydrophobic aid, nano silicon dioxide and a surface tension regulator, adjusting the pH value to 6.5 for later use, and finally sequentially spraying three layers of structures on the surface of a substrate to be sprayed. The coating has wear resistance, elasticity and waterproof performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coating, in particular to a high-elasticity wear-resistant waterproof coating and a preparation method thereof. BACKGROUND

[0002] The coating material of the interior wall and the roof of the building and other parts not only needs to have excellent waterproof performance, but also needs to have good wear resistance, weather resistance and elastic response ability under cold and hot alternation and stress deformation. However, the traditional polyurethane waterproof coating has strong adhesion and good flexibility, but is easy to age and wear in high humidity and strong ultraviolet environment, and has limited waterproof sealing effect; part of the modified epoxy or fluorocarbon coating has strong hydrophobicity and corrosion resistance, but has strong brittleness, insufficient elasticity and anti-cracking performance, and is easy to crack or fail at the interface with stress concentration. In addition, most waterproof materials use single component or simple double-layer design, which is difficult to realize long-term reliable functional coverage on the surface of the building component with complex structure and variable stress.

[0003] At present, some studies try to improve the coating performance by adding elastic fillers or nano additives, but there are problems such as dispersion difficulty, system instability, weak function synergy and the like, which are difficult to simultaneously consider the multiple performances of wear resistance, elasticity and waterproofness.

[0004] Therefore, how to construct a high-elasticity wear-resistant waterproof coating system with multi-level structure division and function component synergy, improve the mechanical cushioning, waterproof sealing and interface adhesion performance, and maintain the stability and workability of the whole system, has become a problem to be solved in the field of protective coating. SUMMARY

[0005] In view of this, the present application provides a high-elasticity wear-resistant waterproof coating and a preparation method thereof, to solve the problem that the multiple performances of wear resistance, elasticity and waterproofness are difficult to be simultaneously considered in the prior art.

[0006] On the one hand, the present application provides a preparation method of a high-elasticity wear-resistant waterproof coating, comprising: Step 1: hollow glass microspheres with a particle size of 15-45 μm are dried at 80℃ for 2h, then 1wt% of fluorosilane treatment solution is sprayed on the surface, and the pretreated hollow glass microspheres are baked in a 80℃ reaction furnace for 3h; Step 2: a) preparation of the base adhesive layer: polyurethane emulsion: 70wt%; modified amino resin: 20wt%; defoamer and leveling agent: 3wt% in total; silica powder: 7wt%; The above components are high-speed sheared and dispersed for 10min, and then standby after standing and defoaming; b) Elastic wear-resistant layer formulation: Elastic modified powder: 25wt%; Polyether type acrylic emulsion: 60wt%; Pre-treated hollow glass microbeads: 10wt%; Zirconium silicate particles: 3wt%; Water-based rheology modifier: 2wt%; The above components are mixed and stirred after pre-emulsification treatment, and are ready for use; c) Waterproof sealing layer formulation: Fluorocarbon emulsion: 80wt%; Hydrophobic additives: 10wt%; Nano-silica: 5wt%; Surface tension modifier: 5wt%; Mix the above components under ultrasonic emulsification for 15min, adjust the pH to 6.5, and then use; Step 3: Spray the base adhesive layer, elastic wear-resistant layer and waterproof sealing layer onto the surface of the material to be sprayed in turn.

[0007] Further, the elastic modified powder is prepared by the following steps: Under nitrogen protection, add propylene oxide and ethylene oxide in a molar ratio of 1:1 into the reaction kettle, add sodium hydroxide and control the temperature at 90℃, stir for 6h to obtain polyether polyol with terminal hydroxyl group, and control the molecular weight at 3000-5000g / mol; Slowly add an equal molar amount of KH570 to the polyether polyol, and the reaction temperature is 60℃, and the reaction time is 3h, to obtain a polyether prepolymer containing polymerizable olefin groups; Add sodium dodecyl sulfate, water and potassium persulfate to the polyether prepolymer, adjust the pH to 7.0, start stirring and keep the temperature at 75℃, add styrene and butadiene monomers dropwise, and react for 4 hours to obtain a polyether block butadiene emulsion.

[0008] Remove residual monomers and low molecular weight impurities by ultrafiltration and centrifugal separation in turn, adjust the solid content to 40%, and spray dry the polyether block butadiene emulsion to prepare an elastic modified powder with a particle size of 100-300nm.

[0009] Further, the molar ratio of styrene and butadiene monomers is 3:2.

[0010] Further, the modified amino resin is prepared by the following steps: The water-based epoxy acrylate emulsion with an epoxy content of 5-10% and a solid content of 30-40% and the amino-terminated polyether with a molecular weight of 1000-3000 and an amino equivalent of 0.5-1.0 meq / g are used as raw materials, the amino-terminated polyether is dissolved in the water phase, the pH is adjusted to 7.5-8.0, then the water-based epoxy acrylate emulsion is added, stirring is carried out at 50-60℃ for 2-3h, cooling is carried out to room temperature, and the pH is adjusted to 6.5-7.5, so that the modified amino resin is obtained.

[0011] Further, the fluorocarbon emulsion is a copolymer of hexafluoropropylene, tetrafluoroethylene and perfluoroalkyl acrylate, and the fluorocarbon emulsion has a solid content of 40-50%.

[0012] Further, the hydrophobic auxiliary agent comprises, by mass, 30% of methylfluorosilane, 25% of octadecyl triethoxysilane, 30% of silicone emulsion, and the balance of dispersants and stabilizers.

[0013] Further, in the base bonding layer, the particle size of the silica fume is <1μm; in the elastic wear-resistant layer, the particle size of the zirconium silicate particle is ≤5μm, and the water-based rheological modifier is sodium carboxymethyl cellulose; in the waterproof sealing layer, the surface tension regulator is a polyethylene glycol-based perfluoroalkyl ether surfactant.

[0014] In another aspect, the application further provides a high-elasticity wear-resistant waterproof coating obtained by the above method.

[0015] Further, the high-elasticity wear-resistant waterproof coating comprises a base bonding layer, an elastic wear-resistant layer and a waterproof sealing layer, and the spraying method of the high-elasticity wear-resistant waterproof coating comprises: Spraying the base bonding layer on the surface of the material to be sprayed, and scraping the thickness to 100-150μm, and standing at room temperature for 6h; In sequence, scraping the elastic wear-resistant layer on the surface of the material, and the thickness is 200-300μm, and then heating and curing at 60℃ for 8h; Spraying the waterproof sealing layer by using the electrostatic spraying method, and the thickness is 50-100μm, and low-temperature drying at 50℃ for 12h, and natural curing for 48h.

[0016] In another aspect, the application further provides the application of the high-elasticity wear-resistant waterproof coating in the waterproofing of the interior wall of a building and the roof of a building.

[0017] Compared with the prior art, the application has the following beneficial effects: The coating of the present application adopts a three-layer structure, namely a base bonding layer, an elastic wear-resistant layer and a waterproof sealing layer, each layer is relatively independent in material composition and functional division, and effective cooperation is achieved through interface compatibility control. The base bonding layer is mainly composed of polyurethane emulsion, modified amino resin and inorganic filler, has certain bonding strength and interface stability, and can be applied to the surface of common substrates such as cement and metal. The intermediate layer forms a composite coating by adding elastic powder with particle size distribution in the range of 100-300 nm and various inorganic reinforcing particles (hollow glass microbeads, zirconium silicate particles), which improves the flexibility and wear resistance to a certain extent. The waterproof sealing layer takes fluorocarbon emulsion as the main film-forming material, combines with nano-sized fillers and organic hydrophobic additives, and can form a dense structure on the surface to isolate water vapor and protect the interface.

[0018] The coating system has good ductility and tensile capacity under experimental conditions, has certain dynamic rebounding capacity, and has excellent wear resistance. No obvious penetration is observed in 72 hours of static water immersion environment, and no visible cracks occur under cold and hot cycle conditions, which meets the protection needs of most indoor and outdoor buildings. In terms of construction adaptability, the coating can be constructed by conventional spraying or batch scraping, the coating surface uniformity and film-forming property are relatively stable, and it is suitable for various application environments. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described below. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0020] The polyurethane emulsion is a commercial water-based polyurethane emulsion, preferably Bayhydrol® UH 2593, Neorez® R-962, Wanhua WPU-3681, and has a solid content of 35-45%, which is used to provide flexibility and adhesion. In the following examples, Bayhydrol® UH 2593 is selected as the polyurethane emulsion.

[0021] Preparation of modified amino resin: Raw material selection: water-based epoxy acrylate emulsion: a water-dispersible epoxy acrylate emulsion with an epoxy content of about 5-10% and a solid content of 30-40% is selected. Amino-terminated polyether: molecular weight of 1000-3000 g / mol, amino equivalent of 0.5-1.0 meq / g, providing active amino groups for crosslinking reaction. Catalyst: an appropriate amount of water-soluble organic amine (such as diethanolamine) or quaternary ammonium salt catalyst to promote the reaction of epoxy and amino. Additives: dispersants, stabilizers and the like to ensure uniform and stable system.

[0022] Specific preparation steps: a) Put the aqueous epoxy acrylate emulsion into the reaction kettle, stir evenly, and control the temperature at 40-50°C.

[0023] b) Add the amino-terminated polyether to the water phase according to the set ratio (epoxy equivalent: amino equivalent is 1:1-1.2:1), fully dissolve and adjust the pH to 7.5-8.0.

[0024] c) Slowly add the aqueous amino-terminated polyether solution to the aqueous epoxy acrylate emulsion while continuously stirring, maintain the temperature at 50-60°C, and react for 2-3 hours. The ring-opening crosslinking reaction between epoxy groups and amino groups occurs to form a modified amino resin.

[0025] d) After the reaction is completed, cool to room temperature, add an appropriate amount of stabilizer and preservative, adjust the system pH to 6.5-7.5, and obtain a stable and uniform modified amino resin emulsion.

[0026] Preparation of fluorocarbon emulsion: Raw material preparation: tetrafluoroethylene (TFE), fluoropropyl methacrylate (PFMA), polyether acrylate (PEA), 2-hydroxyacrylic acid (HEMA), emulsifier (using bio-based non-ionic surfactant) and initiator (ammonium persulfate).

[0027] Preparation process: Step 1: Add deionized water to the reaction kettle, add emulsifier, stir evenly, and adjust the pH to 7.0. Add HEMA and PEA pre-dispersed into the kettle.

[0028] Step 2: Control the reaction temperature at 65°C, slowly add the mixed solution of TFE and fluoropropyl acrylate monomer (volume ratio 7:2) to the reaction kettle, maintain nitrogen protection, and start dropping ammonium persulfate to maintain the polymerization reaction.

[0029] Step 3: During the reaction, maintain the temperature at 65°C±2°C, the stirring speed is 300 rpm, and the reaction time is 4h. Monitor the solid content by sampling, and the target solid content is 40%-45%.

[0030] Step 4: After the polymerization is completed, cool to room temperature, add an appropriate amount of dispersant and stabilizer to improve the long-term stability of the emulsion, and remove the unreacted monomers and impurities by ultrafiltration or membrane separation. Adjust the pH to 6.5-7.0 to obtain the fluorocarbon emulsion. Example

[0031] The base adhesive layer is prepared by mixing the following components: polyurethane emulsion 70%, modified amino resin 20%, defoaming agent and leveling agent 3%, silica powder 7%. The modified amino resin is prepared by reacting an amino-terminated polyether with a water-based epoxy acrylate emulsion: first, the amino-terminated polyether (molecular weight 1000-3000, amino equivalent weight 0.5-1.0 meq / g) is dissolved in the aqueous phase, and the pH is adjusted to 7.5-8.0, then a water-based epoxy acrylate emulsion with an epoxy content of 5-10% and a solid content of 30-40% is added, and the reaction is carried out at 50-60°C for 2-3 hours, and after cooling to room temperature, the pH is adjusted to 6.5-7.5 to obtain the modified amino resin. The above base adhesive layer raw materials are dispersed under high-speed shearing for 10 minutes, and then left to stand and deaerate before use.

[0032] The elastic wear-resistant layer is prepared by mixing the following components: elastic modified powder 25%, polyether-type acrylic emulsion 60%, pretreated hollow glass microbeads 10%, zirconium silicate particles 3%, and water-based rheology modifier 2%. The elastic modified powder is prepared as follows: under nitrogen protection, epoxy propane and epoxy ethane (molar ratio 1:1) are added to a reaction kettle, sodium hydroxide is added as a catalyst, and the reaction is carried out at 90°C for 6 hours to synthesize a polyether polyol with terminal hydroxyl groups (molecular weight controlled at 3000-5000 g / mol). Then, equal moles of KH570 are slowly added to the polyether polyol at 60°C, and the reaction is carried out for 3 hours to obtain a polyether prepolymer containing olefin groups. Subsequently, sodium dodecyl sulfate, water, and potassium persulfate are added to the prepolymer, and the pH is adjusted to 7.0, then styrene and butadiene (molar ratio 3:2) are added dropwise at 75°C, and the reaction is carried out for 4 hours to form a polyether block butadiene emulsion, which is then subjected to ultrafiltration and centrifugation to remove impurities, the solid content is adjusted to 40%, and then spray drying is carried out to obtain elastic modified powder with a particle size of 100-300 nm. The above elastic wear-resistant layer formulation is pre-emulsified and then mixed and stirred to form a coating component that can be uniformly applied.

[0033] It should be noted that when equal moles of KH570 are slowly added to the polyether polyol, the hydroxyl value of the polyether polyol is calculated, and equal moles of KH570 are added based on the hydroxyl value of the polyether polyol.

[0034] The waterproof sealing layer is prepared by mixing the following components: fluorocarbon emulsion 80%, hydrophobic additive 10%, nano-silicon dioxide 5%, and surface tension regulator 5%. The fluorocarbon emulsion is obtained by copolymerization of hexafluoropropylene, tetrafluoroethylene, and perfluoroalkyl acrylate, with a solid content of 40-50%. The hydrophobic additive is composed of 30% methyl fluorosilane, 25% octadecyl triethoxysilane, 30% silicone emulsion, and the balance of dispersants and stabilizers. The surface tension regulator is a polyethylene glycol-based perfluoroalkyl ether surfactant. The above components are mixed under ultrasonic emulsification for 15 minutes, and then the pH is adjusted to 6.5 before use.

[0035] In the spraying process, the base adhesive layer is first applied to the surface of the substrate to be sprayed, and the coating thickness is controlled to be 100-150 pm by using the drawdown method, and the preliminary solidification is completed after standing at room temperature for 6 hours. Then the elastic wear-resistant layer is applied to the surface, the drawdown thickness is controlled to be 200-300 pm, and then the heat curing treatment is carried out at 60°C for 8 hours. Finally, the waterproof sealing layer is sprayed on the surface by using the electrostatic spraying method, the thickness is controlled to be 50-100 pm, and low-temperature drying is carried out at 50°C for 12 hours, and after completion, natural curing is carried out for 48 hours, and a complete three-layer structure coating system is obtained.

[0036] The preparation method is repeated three times, and the samples of examples 1-3 are obtained after sampling.

[0037] The samples in examples 1-3 are subjected to performance detection, the detection items and detection methods are shown in table 1, and the results are shown in table 2.

[0038] Table 1

[0039] Table 2

[0040] Comparative example 1 The difference between this comparative example and the examples is that the modified amino resin is not used in the base adhesive layer, but only a commercial polyurethane emulsion is used instead, which is selected from Bayhydrol® UH 2593 of Bayer Company.

[0041] Comparative example 2 The difference between this comparative example and the examples is that the elastic modified powder in the elastic wear-resistant layer is not subjected to KH570 graft modification, but directly uses a common polyether block styrene emulsion, which is selected from the elastic block emulsion prepolymer Styroflex® series provided by BASF Company.

[0042] Comparative example 3 The difference between this comparative example and the examples is that the spraying process is not divided into three layers, but is one-time whole mixed spraying.

[0043] Comparative example 4 The difference between this comparative example and the examples is that the hollow glass beads and zirconium silicate particles after pretreatment are not added in the elastic wear-resistant layer.

[0044]

[0045] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit it. Although the present application has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and any modification or equivalent replacement should be covered in the protection scope of the claims of the present application.

Claims

1. A method for preparing a highly elastic wear-resistant waterproof coating, characterized in that: include: Step 1: Dry the hollow glass microspheres with a particle size of 15-45 μm at a constant temperature of 80°C for 2 hours, then spray 1wt% fluorosilane treatment liquid on the surface, place it in an 80°C reaction furnace and bake it for 3 hours to obtain the pretreated hollow glass microspheres; Step 2: a) Preparation of base bonding layer: Polyurethane emulsion: 70wt%; Modified amino resin: 20wt%; Defoamer and leveling agent: 3wt% in total; Silica fume powder: 7wt%; Disperse the above components under high-speed shearing for 10 minutes, let them stand for degassing and then set aside; b) Preparation of elastic wear-resistant layer: Elastic modified powder: 25wt%; Polyether acrylic emulsion: 60wt%; Pretreated hollow glass microspheres: 10wt%; Zirconium silicate particles: 3wt%; Water-based rheology modifier: 2wt%; After pre-emulsification, the above components are mixed and stirred for later use; c) Preparation of waterproof sealing layer: Fluorocarbon emulsion: 80wt%; Hydrophobic additive: 10wt%; Nano-silicon dioxide: 5wt%; Surface tension regulator: 5wt%; The above components were mixed under ultrasonic emulsification for 15 minutes, and the pH was adjusted to 6.5 before use; Step 3: Spray the base bonding layer, elastic wear-resistant layer and waterproof sealing layer onto the surface of the material to be sprayed in sequence.

2. The method for preparing a highly elastic wear-resistant waterproof coating according to claim 1, characterized in that: The elastic modified powder is specifically prepared by the following steps: Under nitrogen protection, propylene oxide and ethylene oxide were added in a molar ratio of 1:1 into a reactor, sodium hydroxide was added, and the temperature was controlled at 90° C. The reaction was stirred for 6 hours to obtain a polyether polyol with terminal hydroxyl groups and a molecular weight controlled at 3000-5000 g / mol; Slowly dropwise add an equal mole of KH570 to the polyether polyol at a reaction temperature of 60° C. for 3 h to obtain a polyether prepolymer containing a polymerizable olefin group; Sodium lauryl sulfate, water, and potassium persulfate were added to the polyether prepolymer, the pH was adjusted to 7.0, stirring was started, and the temperature was maintained at 75° C. Styrene and butadiene monomers were added dropwise and reacted for 4 hours to obtain a polyether block styrene butadiene emulsion; The residual monomers and low-molecular impurities are removed by ultrafiltration and centrifugal separation in sequence, the solid content is adjusted to 40%, and the polyether block styrene butadiene emulsion is spray-dried to prepare an elastic modified powder with a particle size of 100-300 nm.

3. The method for preparing the highly elastic wear-resistant waterproof coating according to claim 2, characterized in that: The molar ratio of the styrene and butadiene monomers is 3:

2.

4. The method for preparing a highly elastic, wear-resistant and waterproof coating according to claim 1, wherein: The modified amino resin is prepared by the following steps: Aqueous epoxy acrylate emulsion with an epoxy content of 5-10% and a solid content of 30-40% and amino-terminated polyether with a molecular weight of 1000-3000 and an amino equivalent of 0.5-1.0 meq / g are used as raw materials. The amino-terminated polyether is dissolved in an aqueous phase and the pH is adjusted to 7.5-8.

0. The polyether is then added to the aqueous epoxy acrylate emulsion, stirred and reacted at 50-60° C. for 2-3 hours, cooled to room temperature, and the pH is adjusted to 6.5-7.5 to obtain a modified amino resin.

5. The method for preparing the highly elastic wear-resistant waterproof coating according to claim 1, characterized in that: The fluorocarbon emulsion is a copolymer of hexafluoropropylene, tetrafluoroethylene and perfluoroalkyl acrylate, and the solid content of the fluorocarbon emulsion is 40-50%.

6. The method for preparing the highly elastic wear-resistant waterproof coating according to claim 1, characterized in that: The hydrophobic auxiliary agent includes, by mass, 30% of methylfluorosilane, 25% of octadecyltriethoxysilane, 30% of organic silicon emulsion, and the remainder of a dispersant and a stabilizer.

7. The method for preparing a highly elastic, wear-resistant and waterproof coating according to claim 1, wherein: In the base bonding layer, the particle size of the silica fume powder is less than 1 μm; in the preparation of the elastic wear-resistant layer, the particle size of the zirconium silicate particles is ≤5 μm, and the aqueous rheology modifier is sodium carboxymethyl cellulose; in the waterproof sealing layer, the surface tension regulator is a polyethylene glycol-based perfluoroalkyl ether surfactant.

8. A highly elastic wear-resistant waterproof coating, characterized in that: The preparation method according to any one of claims 1 to 7 is used.

9. The high elasticity, wear-resistant and waterproof coating according to claim 8, characterized in that: The highly elastic wear-resistant waterproof coating comprises a base bonding layer, an elastic wear-resistant layer and a waterproof sealing layer. The spraying method of the highly elastic wear-resistant waterproof coating comprises: Spray the base bonding layer on the surface of the material to be sprayed, with a scraping thickness of 100-150μm, and let it stand at room temperature for 6 hours; Apply an elastic wear-resistant layer on the surface of the material in sequence with a thickness of 200-300 μm, and then heat and cure it at 60°C for 8 hours; Use electrostatic spraying method to spray the waterproof sealing layer with a thickness of 50-100μm, dry it at low temperature of 50℃ for 12h, and naturally cure it for 48h.

10. Use of the preparation method according to any one of claims 1 to 7 in waterproofing interior walls and roofs of buildings.

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