Flame retardants alumina trihydrate based,

Some inorganic fillers are used as flame retardants in rubber base formulations. Flame retardants act in two ways (1) limiting or reducing access of oxygen to the combustion zone (2) reacting with free radicals (especially HO ), thus acting as terminator for combustion-propagation reaction. The additives most widely used as flame retardants for polymers are antimony oxides and alumina trihydrate. 

Flame retardants such as a-alumina trihydrate [14762-49-3] can be added to latex-based foamed carpet backing a combination of antimony oxide [1309-64-4] and chlorinated paraffins is used in dry mbber. 

Intumescents are said to have a key advantage over filler-type non-halogenated flame retardants in that they are effective at lower addition levels than traditional materials. For example, an intumescent based on ammonium polyphosphate will achieve the same level of protection at addition levels of 25 to 35 parts by weight (pbw) as atypical non-halogenated flame retardant, such as alumina trihydrate or magnesium hydroxide, at between 60 and 70 parts by polymer weight. 

In general purpose applications competitively priced thermosets are used for the printed circuit board base material which is usually FR4 (Flame Retardant) . One of the main flame retardants used in America is to have tetrabromobisphenol-A reacted into the epoxy resin. Non-halogen systems include additives such as alumina trihydrate, alumina trihydrate/red phosphorus and aromatic phosphates. Flame retardant epoxy coatings are reported to use ammonium polyphosphate with char-forming additives. 

In this chapter we review results of nanocomposites based on organoclays and carbon nanotubes and the synergistic effects of these fillers with micro-sized alumina trihydrate as a traditional flame retardant for cables. 

This represents a specialty filler which contributes to paper brightness, ink receptivity and acts as a flame retardant. The effect on flame retardancy can be explained by the 35% of bound water based on material weight. The bound water is released at temperatures above 150 °C. The raw material source for the production of aluminum trihydrate (ATH) is bauxite. Bauxite is a blend of AI2O3, Fc203, Si02, H2O, Ti02 and other minerals. To produce ATH it is necessary to stabilize the alumina content and to separate out the other minerals. This is done by the so-called Bayer process. After final filtration, the clear liquor of sodium aluminate is seeded with specially prepared fine crystals of ATH. This seeding causes the sodium aluminate to decompose to ATH or Al(OH)3 which forms a precipitate. 

Since NBR/PVC has basic good flame resistance it may be used in hose and belt applications where this is a requirement. A 70/30 or 50/50 NBR/PVC base elastomer should be selected and use non-black fillers, including alumina trihydrate (e.g.. Hydrated Alumina 983), magnesium hydroxide, and zinc borate (e.g., Firebrake ZB) as flame retardant fillers. Calcium carbonate will assist in reducing smoke emission. In addition a phosphate plasticizer such as Kronitex 100 or chlorinated paraffin like Chlorowax 40 should be used as the only plasticizer types. 

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