Intumescent flame retardant is developed in recent years to phosphorus and nitrogen as the main component of the flame retardant, containing such flame retardant when heated, the surface can form a layer of dense foam carbon layer, play insulation, oxygen barrier Smoke, but also to prevent droplets, has a good flame-retardant properties. Since 1992, China has started a successful research report, so far there are a number of research units engaged in the development of this area, but still no industrial-scale production reports.

 

        There has been no reason to achieve the scale of production may have two: First, the product has not yet been left in the reaction of inorganic acids, reflecting the surface of the fire-retardant products have moisture absorption phenomenon; the other is the expansion of flame retardant NP is the synthesis of some macromolecular compounds , The final step is the solid-phase reaction, its mass transfer, heat transfer process is too complex and has some difficulties in industrialization. Finally, on the inorganic flame retardants need to note is that some people have been attributed to this category of antimony trioxide, but strictly speaking, antimony trioxide itself is not a flame retardant, it is only halogen flame retardant with the synergies . Aluminum hydroxide, magnesium hydroxide is the main force in inorganic flame retardants, especially when promoting halogen-free flame retardant in some areas, they will become the first choice. As the inorganic flame retardants need to add a large amount, in some special cases will exceed the amount of polymer itself, therefore, bound to the physical and mechanical properties of polymers have a very big impact, which requires inorganic Flame retardant treatment, that is, micronization, surface activation.

 

         The purpose of micronization is to make them dispersed in the polymer evenly, in the body everywhere play a role in flame retardant. Experiments show that, in order to achieve the same flame-retardant standards, micro-particles may be appropriate to reduce the amount. Another surface activation is to make the inorganic flame retardants and high polymer compatibility between the good, which can reduce the addition of a large number of inorganic flame retardants caused by the decline in the mechanical strength of the polymer itself. Recently, some articles on the flame-retardant inorganic nanoparticles superiority, our work experience that the addition of these nanoparticles may be beneficial to improve the mechanical strength, but the flame retardant properties will not have much impact. Because the flame retardant mechanism of inorganic flame retardants is released by heat decomposition to reduce the system temperature, while the water vapor dilution of flammable gas to achieve flame retardant effect, it is the amount of water vapor to determine its flame retardant effect, And therefore the amount of flame retardants, flame retardants and whether the nanoparticles have nothing to do, in general, inorganic flame retardant particle size distribution between 2μm 5μm is sufficient.