Ammonium polyphosphate, referred to as APP, is a nitrogen-containing phosphate with a white powder appearance. According to its degree of polymerization, it can be divided into three types: low polymerization, medium polymerization and high polymerization. The greater the degree of polymerization, the smaller the water solubility. Crystalline ammonium polyphosphate is a water-insoluble and long-chain polyphosphate. There are five variants from I to V.

High degree of polymerization crystalline type II ammonium polyphosphate has significant advantages in the field of polymer materials due to its good water insolubility, high decomposition temperature, and good compatibility with polymer materials. Compared with halogen-containing flame retardants, crystalline type II ammonium polyphosphate has the characteristics of low toxicity, low smoke, and inorganic. It is a new type of high-efficiency inorganic flame retardant.

Application development history
In 1857, ammonium polyphosphate was first studied.
In 1961, it was used as a high-concentration fertilizer.
In 1969, the application of new technologies expanded its application to flame retardants.
In 1970, the United States began producing the flame retardant ammonium polyphosphate.
In 1972, Japan began to produce flame retardant ammonium polyphosphate.
In the 1980s, China studied the flame retardant ammonium polyphosphate.

Application fileds
Ammonium polyphosphate is widely used as a flame retardant treatment agent for plastics, rubber, and fibers;
It can also be used to prepare intumescent fire retardant coatings for fire protection treatment of ships, trains, cables and high-rise buildings, as well as fire-retardant wood and paper.
It is also used to produce dry powder fire extinguishing agents for large-scale fire extinguishing in coal fields, oil wells and forests;
In addition, it can also be used as fertilizer.

Global market
With the development of global flame retardants in the direction of halogen-free, intumescent flame retardants using ammonium polyphosphate as the main raw material have become a hot spot in the industry, especially the demand for type II-ammonium polyphosphate with high degree of polymerization.

In terms of regional distribution, North America, Western Europe, Japan and the Asia-Pacific region (excluding Japan) are the four major markets for ammonium polyphosphate. The demand for ammonium polyphosphate in the Asia-Pacific market has grown significantly and has now become the world’s largest consumer market for ammonium polyphosphate, accounting for 55.0% in 2018.

In terms of production, global APP manufacturers are mainly concentrated in North America, Europe and China. The main brands include Clariant, ICL, Monsanto from USA (PhoschekP/30), Hoechst from Germany (Exolit263), Montedison from Italy (SpinflamMF8), Sumitomo and Nissan from Japan, etc.
In the ammonium polyphosphate and liquid fertilizer segment, ICL, Simplot, and PCS are the main companies, and the rest are small and medium-sized enterprises.