What are the types and

There are many kinds of flame retardant, which can be divided into organic flame retardant and inorganic flame retardant. The representative flame retardant is chlorine, bromine, phosphorus, aluminum hydroxide, magnesium hydroxide, etc. There are three kinds of organic flame retardant, and their characteristics are different


First, chlorine flame retardant: chlorinated paraffin with higher chlorine content is the main component, and its application is mainly chlorine wax-52 and chlorowax-40. At present, chlorine flame retardant is developing towards the direction of pollution-free, high purity, high thermal stability and high chlorine content. Its representative product is chlorowax-70. There are no industrial products in China for PCP and reactive chlorine flame retardant chlorobacillic acid.


Second, bromine flame retardant: most of them are decomposed at 200 ℃ ~ 300 ℃. During decomposition, the free radicals generated by degradation reaction of polymer materials are captured to delay or terminate the chain reaction of combustion. The HBr released is a kind of non combustible gas, which can be covered on the surface of the material and can block the combustible gas on the surface. Bromine flame retardant is widely used, and it is one of the largest organic flame retardant in the world. The main products are decabromodiphenyl ether, tetra - bisphenol A, PENTABROMOTOLUENE and hexabromocyclododecane.


Third, phosphorus flame retardant: it is also a kind of flame retardant with good flame retardant performance. Driven by the non halogenation trend of flame retardant, a lot of researches have been carried out abroad. The main products of the flame retardant are triphenol phosphate, xylene phosphate, butylene phosphate, etc. Phosphoesters have the dual functions of flame retardant and plasticizing. The main products of inorganic flame retardant containing phosphorus are red phosphorus flame retardant, ammonium phosphate, ammonium polyphosphate and so on. The flame retardant effect of red phosphorus is better than that of phosphoester. The amount of the product is also increasing. Inorganic flame retardant containing phosphorus has good thermal stability and no volatilization. It has been widely used for its advantages of no corrosive gas, long-term effect and low toxicity.


The decomposition temperature of inorganic flame retardant is high, besides the effect of fire retardant, it also has the effect of inhibiting smoke and hydrogen chloride generation. At present, the consumption of inorganic flame retardant in developed countries is far higher than that of organic flame retardant. The main varieties used are aluminum hydroxide, magnesium hydroxide, red phosphorus, and second step of trioxides. Aluminum hydroxide is a flame retardant which can be used as a flame retardant with three functions: flame retardant, smoke suppression and filling. It is non-toxic, corrosion-free, stable and non poisonous gas at high temperature, and it is cheap and widely used. Magnesium hydroxide is decomposed between 340 ℃ and 490 ℃. It is suitable for polyolefin plastics with high temperature. The composite use of aluminum hydroxide and magnesium hydroxide can complement each other, and its flame retardant performance is better than that of the single use.


The advantages of halogen flame retardant are low dosage, high flame retardant efficiency and wide adaptability, but its serious disadvantage is that a large number of smoke and toxic and corrosive gases are produced during combustion, which is harmful. In recent years, the development of halogen-free flame retardant instead of halogen flame retardant has become the trend of flame retardant development in the world. It has become one of the key research topics in the field of flame retardant to research and develop new flame retardant to reduce the smoke and toxic gas quantity during the combustion of materials. At present, the smoke suppressors are mainly metal oxides and transition metal oxides, mainly including zinc borate, aluminum compounds (alumina, ammonium lead acid) and their complexes, magnesium zinc complex, ferro 2, tin oxide and copper oxide. The synergistic system has good flame retardant effect and low cost, which can be flame retardant and smoke suppressor, and has some special functions. The common collaborative system is mainly halogen-p, antimony phosphorus, phosphorus-nitrogen, etc., so as to improve the flame retardant performance. Red phosphorus is one of the main synergistic systems, which can be used in aluminum hydroxide and nitrogen flame retardant systems.