Next-generation ignition-resistance using silicone

A joint development project between NEC Corporation, Sumitomo Dow and Dow Chemical has resulted in a newly structured silicone derivative as an ignition resistant additive for aromatic plastics, particularly polycarbonate. The additive is said to show greater effectiveness for PC resin than previous silicones. It can replace current ignition resistant additives including halogen and phosphorus compounds. When added to PC, the resin meets the UL 94, V0 standard. As well, PC containing the new silicone has impact strength several times higher than that of PC containing brominated or phosphorus compounds, without addition of modifiers.

The new silicone has a branched chain containing aromatic groups (mainly phenyl) and non-reactive terminals. The structure permits fine dispersion of the silicone in the resin. During combustion the silicone molecules migrate from the inside bulk layers to the surface, forming a uniform, ignition resistant barrier on the surface. The technology is commercial.