High temperature resistant paint generally refers to the paint that does not change color, does not fall off, and can still maintain proper physical properties when the coating film is above 200 ℃. High temperature resistant powder coatings are mainly composed of high temperature resistant resins, high temperature resistant pigments, high temperature resistant fillers and special effect additives; they are widely used in chemical, petroleum, metallurgy, aviation and other industries due to their high temperature resistance. At present, heat-resistant powder coatings are still dominated by silicone powder coatings.
The selection and control of each component in the silicone powder coating is the foundation of the high temperature resistant silicone powder coating. High temperature resistant special resins and high temperature resistant pigments and fillers are made of high temperature resistant plastic powders, which are widely used in ovens, guardrails, automobile brake pads and exterior spray coatings for exhaust pipes.
In high temperature powder coatings, silicone resin is indispensable. We know that silicone resin is mainly based on silicon-oxygen bond. Due to its high bond energy, silicone resin has high oxidation stability and can be used in coating film. A stable protective layer is formed on the surface, but using silicone resin alone, the intermolecular force is relatively small, the adhesion is poor, and the price is relatively high. Silicone to deal with the problem.
Silicone resin is an indispensable base material for high temperature resistant powder coatings. Silicone resin can be used alone as a base material or combined with polyester and epoxy resin to improve the high temperature resistance of the coating film. At the same time, high temperature resistant inorganic pigments and fillers and appropriate additives should also be used in the formula. At present, the silicone resins used for high temperature powder coatings are mainly divided into the following two types:
Methyl polysiloxane, its characteristics are: good hardness; good hydrophobicity; low surface energy, non-stick effect; - good yellowing resistance at high temperature; but poor miscibility with other organic resins. Phenyl polysiloxane, good miscibility; good flexibility; gloss and color retention.