Nitrogen-based FRs, With or Without Phosphorus Compounds

10 Nitrogen-based FRs, With or Without Phosphorus Compounds 

Nitrogen-containing FRs (without any phosphorus compounds) hold only a small share of the global FR market at present, although their popularity is growing. The main active ingredients are usually melamine cyanurate and melamine hydrobromide, although melamine phosphate is used in intumescent FR systems in combination with pentaerythritol. Melamine based flame retardants employ several modes of flame retardant action. 

A recent DuPont patent discloses a novel way of making condensed melamine phosphates. Melamine pyrophosphate made in this way is claimed to have improved thermal stability. Budenheim is another leading producer of melamine compounds, such as melamine phosphate (Budit 310, 312), and pyrophosphate (Budit 311). The latter is an effective low-cost flame retardant with a low water solubility and good thermal stability. It is used in glass filled polyamides. 

Italy s Domus Chemicals produces intumescent compounds containing nitrogen and phosphorus based chemicals for polyolefins and TPEs. Domus also sells melamine hydrobromide as a flame retardant for PP. 

NEC has investigated a benzoguanidine-modified phenolic novolac polymer as a multirole hardener and flame retardant in epoxy polymers for electronic applications. 

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