Water-based silane waterproof agent and preparation method thereof

Abstract

The invention relates to the technical field of waterproof agents, in particular to a water-based silane waterproof agent and a preparation method thereof. A conventional solvent-based waterproof agent for building walls contains a large amount of VOC, and easily causes environmental pollution and health hazards in construction and use processes. In order to solve the technical problems, the invention provides the water-based silane waterproof agent, a water-based system is adopted to replace a traditional organic solvent type waterproof agent, the VOC content can be controlled to be smaller than or equal to 50 g / L and far lower than that of paraffin or asphalt waterproof materials (generally, the VOC is larger than or equal to 500 g / L), release of harmful substances in the construction and use process is effectively reduced, and the water-based silane waterproof agent meets the requirements of green buildings and environmental protection laws and regulations; hydrophobic chain segments of long-chain alkyl siloxane in the formula can penetrate into micropores of a building base material to form a physical waterproof layer, the hydrolysis-condensation reaction rate is optimized through the acid catalyst, a more compact three-dimensional siloxane network is formed, and the waterproof effect is more excellent.

Description

Technical Field

[0001] This invention relates to the field of waterproofing agent technology, specifically to an aqueous silane waterproofing agent and its preparation method. Background Technology

[0002] Among existing building waterproofing materials, organic solvent-based waterproofing agents (such as paraffin and asphalt-based agents) contain large amounts of volatile organic compounds (VOCs), which easily cause environmental pollution and health hazards during construction and use, and have been gradually replaced by water-based environmentally friendly waterproofing agents. However, although early water-based silane waterproofing agents had the advantage of low VOCs, their waterproofing performance was often limited by the following problems: Insufficient permeability: The interfacial bonding force between silane molecules and the substrate (such as concrete, brick and stone) is weak, making it difficult to form a deep-penetrating waterproof layer; Poor durability: When exposed to ultraviolet rays, moisture or temperature changes for a long time, the coating is prone to aging and peeling. Low reaction efficiency: Silane hydrolysis and condensation reactions require strict conditions (such as pH and temperature). Traditional formulations do not optimize the synergistic effect of catalysts and solvents, resulting in unstable film quality. Summary of the Invention

[0003] The problem with existing technologies is that conventional solvent-based waterproofing agents for building walls contain a large amount of volatile organic compounds (VOCs), which can easily cause environmental pollution and health hazards during construction and use. To address the above technical problems, this invention provides a water-based silane waterproofing agent, which, by weight, comprises the following raw material components: 100 parts of long-chain alkylsiloxane; 30-200 parts of silane coupling agent; 17-83 parts of acidic catalyst; Solvent: 50-300 parts.

[0004] Preferably, the long-chain alkylsiloxane includes one or both of octyltrimethoxysilane or hexadecyltrimethoxysilane.

[0005] Preferably, the silane coupling agent is one or both of KH550 and KH540.

[0006] Preferably, the acidic catalyst is one or both of formic acid or acetic acid aqueous solution.

[0007] Preferably, the solvent is isopropanol or butanol.

[0008] The present invention has the following beneficial effects: (1) The present invention uses a water-based system to replace the traditional organic solvent-based waterproofing agent. The VOC content can be controlled at ≤50g / L, which is much lower than that of paraffin or asphalt waterproofing materials (usually VOC≥500g / L). This effectively reduces the release of harmful substances during construction and use, and meets the requirements of green building and environmental protection regulations. (2) The hydrophobic segments of long-chain alkylsiloxanes (such as octyl / hexadecyltrimethoxysilane) in the waterproofing agent of the present invention can penetrate deep into the micropores of building substrates (concrete, masonry) (penetration depth ≥3mm) to form a physical water-blocking layer; (3) The amino or epoxy groups of the silane coupling agent (KH550 / KH540) in the waterproofing agent of the present invention react with Si-OH on the substrate surface to generate covalent bonds (Si-O-Si), which significantly improves the adhesion strength between the coating and the substrate (adhesion ≥1.5MPa). (4) The acidic catalyst (formic acid / acetic acid) in the waterproofing agent of the present invention optimizes the hydrolysis-condensation reaction rate, forming a denser three-dimensional siloxane network, resulting in excellent waterproofing effect; (5) The water-based waterproofing agent obtained in this invention is diluted to a concentration of 5-10% with warm water at 60-70℃. This accelerates the hydrolysis of silane (endothermic reaction) and avoids uncontrolled solvent evaporation caused by high temperature, ensuring the uniformity of the coating (leveling time after coating ≤10min). The diluted solution is applicable to various construction methods such as spraying, rolling or brushing, and the coverage efficiency of complex wall surfaces (such as cracks and uneven surfaces) is improved by ≥30%. (6) The isopropanol / butanol component in the waterproofing agent of the present invention has excellent compatibility with the silane component, which solves the precipitation problem caused by traditional alcohol solvents and has excellent storage stability; (7) Compared with imported similar products, the raw material cost of the water-based waterproofing agent obtained by the present invention is reduced by about 25%, and no special equipment (such as high temperature oven) is required for construction. The labor cost is reduced by 15-20%, which gives it significant market competitiveness. Detailed Implementation

[0009] The present invention will be described in detail below with reference to embodiments. However, it should be understood that the following embodiments are merely illustrative examples of implementation of the present invention and are not intended to limit the scope of the present invention. Example

[0010] A water-based silane waterproofing agent, prepared by the following method: 100g of octyltrimethoxysilane, 188.9g of KH550, and 288g of butanol were added to a 1L three-necked flask and stirred until homogeneous. 82.9g of formic acid aqueous solution (mass concentration of 88%) was slowly added dropwise while stirring at 40°C. After the addition was complete, the mixture was stirred at a constant temperature of 40°C for 3 hours. Then, a vacuum (vacuum degree of 50Pa) was applied to remove low-boiling substances, yielding 460g of a yellow solid product with a solid content of 40%. Example

[0011] A water-based silane waterproofing agent, prepared by the following method: 100g of octyltrimethoxysilane, 94.4g of KH550, and 194g of butanol were added to a 1L three-necked flask and stirred until homogeneous. 47.1g of formic acid aqueous solution (mass concentration of 88%) was slowly added dropwise while stirring at 40°C. After the addition was complete, the mixture was stirred at a constant temperature of 40°C for 3 hours. Then, a vacuum (vacuum degree of 50Pa) was applied to remove low-boiling substances, yielding 330g of a yellow solid product with a solid content of 41%. Example

[0012] A water-based silane waterproofing agent, prepared by the following method: 100g of octyltrimethoxysilane, 47.2g of KH550, and 147g of butanol were added to a 1L three-necked flask and stirred until homogeneous. 28.8g of formic acid aqueous solution (mass concentration of 88%) was slowly added dropwise while stirring at 40°C. After the addition was complete, the mixture was stirred at a constant temperature of 40°C for 3 hours. Then, a vacuum (vacuum degree of 50Pa) was applied to remove low-boiling substances, yielding 270g of a yellow solid product with a solid content of 46%. Example

[0013] A water-based silane waterproofing agent, prepared by the following method: 100g of hexadecyltrimethoxysilane, 31.94g of KH550, and 50g of butanol were added to a 0.5L three-necked flask and stirred until homogeneous. 17.4g of formic acid aqueous solution (mass concentration of 88%) was slowly added dropwise while stirring at 35°C. After the addition was complete, the mixture was stirred at a constant temperature of 35°C for 3 hours. Then, a vacuum (vacuum degree of 50Pa) was applied to remove low-boiling substances, yielding 167g of a yellow solid product with a solid content of 70%. Example

[0014] A water-based silane waterproofing agent, prepared by the following method: 100g of hexadecyltrimethoxysilane, 63.89g of KH550, and 61g of butanol were added to a 0.5L three-necked flask and stirred until homogeneous. 28.7g of formic acid aqueous solution (mass concentration of 88%) was slowly added dropwise while stirring at 35°C. After the addition was complete, the mixture was stirred at a constant temperature of 35°C for 3 hours. Then, a vacuum (vacuum degree of 50Pa) was applied to remove low-boiling substances, yielding 200g of a yellow solid product with a solid content of 70%. Example

[0015] A water-based silane waterproofing agent, prepared by the following method: 100g of hexadecyltrimethoxysilane, 127.75g of KH550, and 84g of butanol were added to a 0.5L three-necked flask and stirred until homogeneous. 51.45g of formic acid aqueous solution (mass concentration of 88%) was slowly added dropwise while stirring at 35°C. After the addition was complete, the mixture was stirred at a constant temperature of 35°C for 3 hours. Then, a vacuum (vacuum degree of 50Pa) was applied to remove low-boiling substances, yielding 282g of a yellow solid product with a solid content of 70%.

[0016] Performance testing The waterproofing agents obtained in Examples 1-6 of this invention were diluted with warm water at 60°C to different concentrations, loaded into a sprayer, and evenly sprayed onto the exterior wall surface (1m×1m). After natural drying, the coating surface was sprayed again with a sprayer to observe the waterproofing effect of the coating. The appearance of the waterproofing agents obtained in Examples 1-6 of this invention and the waterproofing effect of the formed waterproof coatings are shown in Table 1.

[0017] Table 1 , The test results in Table 1 show that applying the water-based waterproofing agent obtained in this invention to the exterior wall surface of a building to form a waterproof coating can effectively prevent water from eroding the wall surface.

[0018] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A water-based silane waterproofing agent, characterized in that, By weight, it includes the following raw material components: 100 parts of long-chain alkylsiloxane; 30-200 parts of silane coupling agent; 17-83 parts of acidic catalyst; Solvent: 50-300 parts.

2. The water-based silane waterproofing agent according to claim 1, characterized in that, The long-chain alkylsiloxanes include one or both of octyltrimethoxysilane or hexadecyltrimethoxysilane.

3. The water-based silane waterproofing agent according to claim 1, characterized in that, The silane coupling agent is one or both of KH550 or KH540.

4. The water-based silane waterproofing agent according to claim 1, characterized in that, The acidic catalyst is one or both of formic acid or acetic acid aqueous solution.

5. The water-based silane waterproofing agent according to claim 1, characterized in that, The solvent is isopropanol or butanol.

6. A method for waterproofing building walls, characterized in that, A waterproof coating is formed on a building wall using the water-based silane waterproofing agent according to any one of claims 1-5.

7. A method for waterproofing building walls according to claim 6, characterized in that, Waterproof coatings are applied by diluting water-based silane waterproofing agent with warm water to a concentration of 5-10%.

8. A method for waterproofing building walls according to claim 7, characterized in that, The temperature range of the warm water is 60-70℃.