Method for promoting high temperature heat stability of melamine derivative fire retardant by utilizing inorganic and alkyl metallic phosphites, product and application thereof

The invention discloses a method for promoting high temperature heat stability of a melamine derivative fire retardant by utilizing inorganic and alkyl metallic phosphites. The method comprises the step of adding a compound of inorganic metallic phosphite and alkyl metallic phosphite into raw materials; the addition of the compound is 0.1-40%, on the basis of the total weight of the melamine derivative fire retardant; the weight ratio of inorganic metallic phosphite to alkyl metallic phosphite is at 1:(1-10); the structural formula of alkyl metallic phosphite is shown by formula (I) or (II); Ris selected from straight chain fat alkyl with 1-6 aryl groups or carbons and Me is selected from zinc, calcium or magnesium. According to the method disclosed by the invention, the melamine derivative has high thermal decomposition temperature and can overcome the defects of decomposition and degradation of substrate polymer, migration, corrosion to equipment, and the like, of fire retardant, and meanwhile, the property