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CN-122011928-A - Silicone resin bare concrete coating and preparation method thereof

CN122011928ACN 122011928 ACN122011928 ACN 122011928ACN-122011928-A

Abstract

The invention discloses a silicone resin bare concrete coating and a preparation method thereof, belonging to the technical field of building coatings, wherein the silicone resin bare concrete coating comprises, by weight, 25-35 parts of methyl phenyl silicone resin, 10-20 parts of reactive silane oligomer, 3-8 parts of hydrophobic modified nano aluminum oxide, 0.5-1.5 parts of wetting dispersant, 0.3-0.8 part of defoamer, 0.2-0.6 part of leveling agent and 40-50 parts of mixed solvent, wherein the reactive silane oligomer is a condensation reaction product of hydroxyl-terminated polydimethylsiloxane and gamma-aminopropyl triethoxysilane, the hydrophobic modified nano aluminum oxide is nano particles with surfaces treated by long-chain alkyl silane, and the silicone resin bare concrete coating prepared by the invention simultaneously has the comprehensive excellent performances of high adhesion, superhydrophobicity, high air permeability, strong weather resistance, and solves the key problems of water resistance, air permeability, foaming easiness, insufficient durability and the like in the existing bare concrete protective coating.

Inventors

  • WU JIAHUA
  • FANG LIANG
  • JIANG YOU

Assignees

  • 黄山华康新材料科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260129

Claims (10)

  1. 1. The silicone bare concrete coating is characterized by comprising the following components in parts by weight: 25-35 parts of methyl phenyl silicone resin, 10-20 parts of reactive silane oligomer, 3-8 parts of hydrophobic modified nano alumina, 0.5-1.5 parts of wetting dispersant, 0.3-0.8 part of defoamer, 0.2-0.6 part of flatting agent and 40-50 parts of mixed solvent; The reactive silane oligomer is a condensation reaction product of hydroxyl-terminated polydimethylsiloxane and gamma-aminopropyl triethoxysilane, the viscosity of the reactive silane oligomer is 210-480 mPa.s at 25 ℃, and the hydrophobic modified nano-alumina is nano-particle with the surface treated by long-chain alkylsilane and the average particle size of 20-50 nm.
  2. 2. The silicone bare concrete coating according to claim 1, wherein the methyl phenyl silicone has a phenyl content of 20-30%, a hydroxyl content of 3-6%, and a viscosity of 800-1500 mPa-s at 25 ℃.
  3. 3. The silicone bare concrete coating according to claim 1, wherein the reactive silane oligomer is prepared by the following method: mixing hydroxyl-terminated polydimethylsiloxane and gamma-aminopropyl triethoxysilane according to the mass ratio of 1:0.1-0.2, and reacting for 4-6h at 65-75 ℃ under the protection of nitrogen to obtain the reactive silane oligomer.
  4. 4. The silicone bare concrete coating according to claim 1, wherein the long-chain alkylsilane is dodecyl or hexadecyltrimethoxy silane, and the contact angle of the hydrophobically modified nano aluminum oxide is greater than 130 °.
  5. 5. The silicone bare concrete coating according to claim 1, wherein the mixed solvent is prepared by compounding xylene, n-butanol and propylene glycol methyl ether acetate according to a mass ratio of 5:3:2.
  6. 6. The silicone bare concrete coating according to claim 1, wherein the wetting dispersant is polyether-modified polydimethylsiloxane, the defoamer is polyether-modified organosilicon defoamer, and the leveling agent is polyester-modified organosiloxane.
  7. 7. The method for preparing the silicone bare concrete coating according to claim 1, comprising the following steps: S1, mixing hydrophobic modified nano alumina with a mixed solvent with a total dosage of 1/3 and a wetting dispersant, and uniformly dispersing by ultrasonic to obtain nano slurry; S2, adding the methyl phenyl silicone resin into the rest mixed solvent, stirring and dissolving to obtain a main resin solution; And S3, adding the reactive silane oligomer into the main resin solution, stirring and mixing uniformly at a low rotation speed, then slowly adding the nano slurry, increasing the speed to a high rotation speed after the addition, stirring and mixing uniformly, finally adding the defoaming agent and the leveling agent, continuing to stir uniformly, and filtering to obtain the silicone bare concrete coating.
  8. 8. The method for preparing a silicone bare concrete coating according to claim 7, wherein the temperature of the ultrasonic dispersion is 20-40 ℃.
  9. 9. The method for preparing the silicone bare concrete coating according to claim 7, wherein the low-rotation stirring speed is 300-500rpm, the high-rotation stirring speed is 800-1000rpm, and the stirring temperature is 25-35 ℃.
  10. 10. The method for preparing a silicone bare concrete coating according to claim 7, wherein the solid content of the coating is 35.5-44.8% and the viscosity at 25 ℃ is 155-240 mpa.s.

Description

Silicone resin bare concrete coating and preparation method thereof Technical Field The invention belongs to the technical field of building coatings, and particularly relates to a silicone bare concrete coating and a preparation method thereof. Background The bare concrete is widely applied in the building with the unique decorative effect, but the porous structure and chemical composition of the bare concrete are easy to be corroded by environmental factors such as water, carbon dioxide, chloride ions, ultraviolet rays and the like, so that the problems of carbonization, steel bar corrosion, surface wind and the like are caused. Applying protective coatings is one of the most direct and effective means of protection. Silicone resin coatings are considered ideal choices for bare concrete protection due to their excellent weatherability, high and low temperature resistance, breathability and hydrophobicity. However, the existing silicone concrete protective coating still has the following defects: adhesion limitation is that the adhesion between a common silicone coating and a concrete substrate still mainly depends on physical adsorption and limited Van der Waals force, and the coating is easy to have the problems of adhesion drop, foaming and even spalling under the conditions of humid environment, temperature difference stress or long-term exposure; the contradiction between permeation and film formation is that a certain film formation continuity is needed for the coating, which often requires the resin to have higher molecular weight, but the high molecular weight resin is difficult to penetrate into the microporous structure of the concrete, so that the anchoring effect of the coating and the matrix is limited, and the strengthening effect on the matrix is weak; The high-hydrophobicity coating can effectively prevent water, but sometimes excessively obstruct the water vapor emission in the concrete, and the good water vapor permeability of the coating is maintained on the premise of not obviously reducing the hydrophobicity, so that the high-hydrophobicity coating is a technical difficulty; The storage stability and construction property of the paint are that nano materials are added in the silicone resin paint to improve the performance, but nano particles are easy to agglomerate, and the storage stability, the appearance and the uniformity of the final coating of the paint are affected. Therefore, the silicone resin bare concrete coating which has strong adhesive force, excellent hydrophobicity and moderate air permeability, can generate a certain reinforcing effect on a matrix and is stable in storage is developed, and has important practical significance. Disclosure of Invention The invention aims to provide a silicone resin bare concrete coating and a preparation method thereof, and the multi-purpose aims of tough combination of the coating and a concrete matrix, superhydrophobicity of the surface, communication of internal water vapor, long-term stability of the system and the like are realized through unique formula design and step-by-step preparation process, so as to solve the problems in the background technology. The aim of the invention can be achieved by the following technical scheme: The silicone bare concrete coating comprises the following components in parts by weight: 25-35 parts of methyl phenyl silicone resin, 10-20 parts of reactive silane oligomer, 3-8 parts of hydrophobic modified nano alumina, 0.5-1.5 parts of wetting dispersant, 0.3-0.8 part of defoamer, 0.2-0.6 part of flatting agent and 40-50 parts of mixed solvent; The reactive silane oligomer is a condensation reaction product of hydroxyl-terminated polydimethylsiloxane and gamma-aminopropyl triethoxysilane, the viscosity of the reactive silane oligomer is 210-480 mPa.s at 25 ℃, and the hydrophobic modified nano-alumina is nano-particle with the surface treated by long-chain alkylsilane and the average particle size of 20-50 nm. Further, the phenyl content of the methylphenyl silicone resin is 20-30%, the hydroxyl content is 3-6%, and the viscosity at 25 ℃ is 800-1500 mPa.s. The methyl phenyl silicone resin is used as a main film forming substance to provide a basic framework of the coating, and endows the coating with good flexibility, weather resistance and certain reactivity. Further, the reactive silane oligomer is prepared by the following method: Mixing hydroxyl-terminated polydimethylsiloxane and gamma-aminopropyl triethoxysilane according to the mass ratio of 1:0.1-0.2, and reacting for 4-6h at 65-75 ℃ under the protection of nitrogen to obtain the oligomer containing active siloxane end groups and amino side groups. The oligomer has the characteristics of relatively low molecular weight, small viscosity, easiness in penetration into the depth of a concrete capillary hole, capability of carrying out condensation reaction with silicon hydroxyl groups on the surface of the concrete by reserving hydrolyzable siloxane