The commonly used halogen-free flame retardants in PC mainly include three types: phosphorus based, sulfonic acid based, and silicon based.
Nowadays, PC synthesis manufacturers sell related products, but the flame retardant performance varies greatly. Overall, the flame retardant rating of commercially available opaque PCs is between 0.7 and 1.0mmV0, while the flame retardant rating of semi transparent PCs is between 1.1 and 1.6mmV0, and the highest flame retardant rating of transparent PCs is only 1.5mmV0.
According to analysis, transparency is the key factor determining the high flame retardant rating of the high flow halogen-free flame retardant PC market. Traditional phosphorus and silicon flame retardants are themselves semi transparent/transparent liquids, and their powdery substances appear pale yellow or white, which have varying degrees of impact on the transparency of PC. The development of high-efficiency, transparent, halogen-free, and phosphorus free flame retardants will be a key technology. Currently, there is not much research in this area in China, mainly focusing on the development of silicon containing flame retardants.
