Thread Content
Polyesters are the products of the reaction between organic acids and alcohols. The polyester used in glass flake coatings is primarily derived from the reaction of unsaturated dibasic acids with dihydroxy alcohols. It dissolves in styrene monomer; upon adding a catalyst and a curing agent, the styrene begins to cross-link, forming a solid coating film. If the surface of the coating comes into contact with oxygen in the air, it will prevent curing; therefore, applying paraffin to the surface of the paint film can effectively block oxygen and prevent styrene from evaporating during the polymerization reaction. During curing, there is significant shrinkage accompanied by an exothermic reaction. Therefore, adding glass flakes can absorb this contraction force. Polyester glass flake coatings cure rapidly, with a solid content of 96–100%, and provide long-term corrosion protection for steel structures, especially in terms of pressure resistance. Special formulations can also be used on concrete surfaces. Solvent-resistant, chemical-resistant, water-resistant and corrosion-resistant; can be used as an inner lining for storage tanks. On the steel structures of oil platforms, it can be used in many types of structures, and is particularly suitable for helicopter decks. Two-component polyester glass flake coatings can be applied at room temperature, but their storage life is extremely short; this is due to the presence of MEK peroxides, and at 20°C their shelf life is only 40–45 minutes, accompanied by heat release. The temperature ranges from 25 to 40°C, and a retarding inhibitor can be added. A two-component spray pump can be used during construction, or conventional high-pressure airless spraying can also be employed. When the temperature is below 20°C and drops to 10°C (which is also the lowest temperature at which construction can take place), the amount of MEK used must be increased. When constructing, please follow the curing agents to be used at different temperatures. Polyester coatings free of styrene, in which vinyl toluene replaces styrene, eliminating odors and meeting environmental standards. When using a two-component spray painting pump, it is possible to carry out work at temperatures as low as 5°C, but with conventional airless spray pumps, a minimum temperature of 10°C is still recommended. At 23°C, the dry film thickness of polyester glass flake coating ranges from 600 to 1500 microns, and it can be handled or walked on after just 2 hours. It exhibits excellent performance in both freshwater and seawater. High wear resistance, suitable for deck passages, helipads, icebreaker hulls, and tidal splash areas of steel or concrete structures. Resistance to cathodic protection coating peeling. Good chemical resistance, including to crude oil, lubricating oils, saline solutions, and other acids and solvents. Its alkali resistance is average. Due to the very high coating thickness, both concrete and steel require sandblasting; for steel, the roughness level Sa2.5 with an Rz value of 40–100 micrometers is required.