The commonly used waterproof materials for decoration are petroleum asphalt polyurethane waterproof coatings, environmentally friendly polyurethane waterproof coatings, and polymer cement waterproof coatings. Polyurethane waterproof coating has been widely used in waterproof engineering because of its excellent physical and chemical properties. Of these, tar-based polyurethanes are the most widely used. However, with the development of society and the improvement of people’s living standards, people began to pay more attention to environmental protection and their own health. Coal tar contains a large number of aliphatic and aromatic compounds, and has a strong irritating odor. Among them, cesium, naphthalene and other components are extremely harmful to the human body. The pollution of tar-type polyurethanes to the environment has drawn increasing attention. In 1997, the Beijing Municipal Construction Commission proposed that manufacturers wish to develop environment-friendly polyurethane waterproof coatings. At the end of 1998, the "Restriction and elimination of tar-type polyurethane waterproof coatings" was issued. The Beijing Municipal Construction Committee also encourages the development and recommendation of six environmentally friendly polyurethane waterproof coatings: (1) One-component polyurethane waterproof coating (2) Color Polyurethane Waterproof Coating (3) Inorganic filler type polyurethane waterproof coating (4) Water Curable Polyurethane Waterproof Coating (5) Petroleum pitch-based polyurethane waterproof coating (6) Petroleum resin polyurethane waterproof coating The former four are not used in the market because of their high cost. The latter two have become the direction of development of various companies and have been applied in the market. Now advocating the promotion of non-tar type polyurethane waterproof coatings is mainly based on environmental requirements. The difference between tar and non-tar polyurethane waterproof coatings 1 Odor Tar type: There is a severe irritating odor and the coating has odor; Non-tar type: only slight odor or odorless, no obvious odor. 2 coating combustion method Tar type: It has a pungent odor, produces a dense black smoke with black floc formation, and burns rapidly; Non-tar type: It has a loose or slight odor, produces a small amount of black smoke, and is slow to burn. It is incombustible to leave the fire source. 3 mixed method Tar type: The viscosity increases at the initial stage of mixing, that is, there is a thickening phenomenon when stirring; Non-tar type: The viscosity does not change during compounding and there is no thickening phenomenon. The above three methods can basically determine qualitatively the tar-type and non-tar-type polyurethane waterproof coatings, thus preventing the tar-type polyurethane coatings from entering the market. Paint coating buy paint cement
Experts teach you how to identify waterproof coatings