Various methods can be used to impart self-extinguishing property to unsaturated polyester resins, such as chemical modification method, which is called reactive self-extinguishing polyester, and physical-mechanical mixing method, which is called additive self-extinguishing polyester. ﹒ ﹒ ﹒ ﹒ Wait. Additive and reactive self-extinguishing polyester resins have their own shortcomings and shortcomings. In the case of low requirements, the additive method is simple and easy to solve the problem quickly. The disadvantage is that when the flame retardant is added, it will greatly To reduce the light transmission performance of glass fiber reinforced plastics or cast products, reactive self-extinguishing polyester basically overcomes the above shortcomings, but the manufacturing process is more complicated and the cost is also high. Several methods are described as follows:
1. Adding inorganic fillers, from safety considerations, in order to prevent the polyester resin from burning a lot of harmful gases, it is required to reduce the amount of smoke as much as possible. Therefore, polyester varieties containing halogen and antimony trioxide and other inorganic compound flame retardants for self-extinguishing purposes are increasingly eliminated, and non-toxic inorganic flame retardant additives are tended to be added, especially hydrated alumina or borate. .
2. Add organic flame retardant, chlorinated paraffin (chlorine content 65 ~ 70%) widely used flame retardant. The chlorine content of 40% or 45-50% can be used as a flame-resistant plasticizer, which is better mixed with antimony trioxide.
Hexabromobenzene with 86% bromine content, good thermal stability, is a white crystalline powder, mixed according to the formula, which has good flame retardancy.