Introduction of Silicone Coatings（II）
Silicone resin coatings:
"Respiratory" Organic Silicon Waterproof Coatings
Absorption of water by wall materials will cause serious damage to the wall itself. Water in the wall needs to be evaporated from the wall materials in the form of water vapor through a smooth passage. Therefore, reducing the water absorption of building materials and giving the exterior wall materials breathing function are important ways to improve the decoration and waterproof performance of buildings. Silicone coatings mainly consist of organopolysiloxane with certain reactive groups. Its main chain structure has strong chemical affinity, and a small number of active groups on the macromolecule react with hydroxyl groups in the silicate matrix during the film forming process. Because the coating does not close the capillary passage, the moisture inside the base material can diffuse outward in time to ensure that the base material has a good "breathing" function. The coating can be used for external wall protection of high-grade buildings. Using silicone resin to form a layer of film material on the surface of buildings can effectively improve the weatherability of building surface (wind erosion resistance, rain soaking resistance and acid rain erosion resistance), which has a certain practical application value for the protection of high-end buildings, especially ancient buildings.
Organosilicon Elastic Decorative Coatings
Silicone latex elastic decorative coating is a new type of film-forming material by introducing silicone bond into acrylic resin. The addition of silicone improves the weatherability and durability of acrylic resin. The elongation of the coating reaches 300%-700%. It covers up the micro cracks on the wall and improves the decorative function of the coating. Composite polymer latex solution is prepared by multi-step emulsion polymerization. The center is hard resin. Compared with ordinary rubber residue, the film has better elasticity and water resistance, higher gloss and hardness, and high stain resistance. It is a functional coating with great development prospects. Reactive silicone latex solution is synthesized by the polymerization of raw rubber, crosslinking agent and catalyst under certain conditions. After losing water, the solution can cross-link at room temperature to form a monolithic film of silicone latex with network structure.
Silicone elastic latex architectural decorative coatings, easy to operate and control, stable product performance, good cohesion, aging resistance, weather resistance, impermeability and flexibility, to adapt to bad factors caused by wall cracking and seasonal typhoon, rainwater pressure penetration.
Elasto-plastic Silicone "Three-proof" Coatings
Among all the "three-proof" coatings at present, the elastic-plastic silicone "three-proof" coatings have the best comprehensive properties, which can be cured at room temperature or low temperature and are convenient for construction. The cured coating has not only the flexibility of rubber, but also the smooth and transparent surface. It also has the advantages of high and low temperature impact resistance, good high frequency dielectric property and excellent "three-proof" performance. It can meet the protection coating of high, low frequency band and mixed circuit of the whole machine.
The coating is a block copolymer of linear polysiloxane and organosilicon resin. It is prepared by copolycondensation of linear polysiloxane with different organosilicon monomers in the presence of solvents under the action of catalyst. It is a kind of dimethylbenzene solution with a resin content of 50%-60%. It has good storage stability at room temperature. After adding drier, it can solidify into film at room temperature. It can be used for moisture-proof treatment of capacitors, impregnation of porous ceramic materials and protective coating of petroleum instruments in electrical, electronic, petroleum and pharmaceutical industries. It can be used as QM type core. Protective materials for visceral pacemaker, etc. Because of its good transparency, dust resistance, atmospheric aging resistance, ultraviolet aging resistance and other properties, it is also an ideal material for solar cell outer glass packaging.
Construction of silicone resin coatings:
Base treatment: The surface of the base should be flat, and no bumps, bumps, sand and other phenomena should be allowed.
(2) Joint treatment: If the roof has more than 3 mm cracks, the sealing material should be filled, and then the coating should be scraped.
(3) Scraping coating: Rolling, scraping, painting and brushing can be used in construction. Generally, 3-4 routes of scraping can be applied, with reference amount of 0.8-1.0 Kg/m2 for each course.
(4) The total thickness of the coating is more than 1.5 mm, and the interval of each coating is 2-12 hours (depending on the weather). 1-2 layers of fiberglass cloth or other matrix material can be added in the middle of the coating. [1]
Reference material:
1. New Paint Net
Expanding reading:
2. Classification of indoor wall coatings and different painting methods
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