| Product Description: Akrosperse Sb2O3 is a dispersion of 85% active antimony oxide in an EPR (ethylene-propylene copolymer) binder. Antimony trioxide (commonly called antimony oxide) is used as a synergistic fire retardant in elastomeric systems. By itself, Sb2O3 offers no flame resistance; it must be used in conjunction with a halogen (Cl or Br typically) source to effect the burning process. HCl formed from the chlorine source reacts with Sb2O3 to form antimony trichloride which then reacts with hydroxyl radicals in the pyrolysis zone to short-circuit the propagation of the combustion reaction. Applications: Akrosperse Sb2O3 is an excellent flame retarder for elastomeric and plastic compounds with a typical loading range of 4 - 20phr. Chlorine-bearing additives like chlorinated paraffins (Akrochlor?) should be added at a 10-30 phr level (Note: EPDM is not highly compatible with chlorinated paraffins. Use a higher molecular weight chlorinated resin to prevent bleed). Halogenated compounds (CR, NBR/PVC) may not require additional halogen donors. The rubber-bound form is a proven method of reducing skin irritation sometimes produced by handling antimony trioxide. The use of Sb2O3 and Cl to reduce fire has the drawback of creating more smoke in a fire (sometimes acidic smoke due to the HCl present). A compounder should use alumina trihydrate (ATH) along with the Sb2O3 system to reduce smoke as much as possible in rubber compounds. In plastic compounds, the use of magnesium hydroxide (Versamag®) or magnesium carbonate (Elastocarb®) will decrease smoke levels. Information provided by Akrochem Corporation |
