Thursday, May 14, 2009

The Uses of Antimony Trioxide

The main derivative of antimony metal, which can be found in mines in China, Bolivia, Russia, and South Africa, is antimony trioxide or antimony oxide. The main use for antimony oxide is as a flame retardant synergist. That means that it is used in synergy with a halogenated compound to increase the halogenated compound's ability to flame retard. The presence of the synergist allows much less halogenated product to be added to whatever you are trying to protect against flammability. Usually about half as much halogenated compound is needed if you use an antimony oxide synergist. Many industries use antimony as a flame retardant synergist including but not limited to the plastics, textiles, rubber, paper, and paint industries. You can use this product as an appropriate synergist for flame retarding polyvinyl chloride (PVC), polypropylene (PP), high impact polystyrene (HIPS), polyethylene (PE), ethylene propylene diene M-class rubber (EPDM), acrylonitrile butadiene styrene (ABS), epoxies, phenolics, polyurethanes, and many others. It is usually sold in powder form along with powdered halogenated compounds. However, some companies sell liquid dispersions that include both the antimony trioxide and halogenated compound in the appropriate ratios.

Trivalent antimony oxide also has other uses. One large application is as a catalyst in polyethylene terephthalate polymerization. Typically, a higher purity grade is used for this purpose. Antimony is the preferred catalyst for PET manufacturing because the cost/performance ratio is considered optimal. There are other PET catalysts that are more efficient; but they have historically been much more expensive than their antimony counterpart. There is a small amount of concern over the possible migration of the antimony into the liquids contained in PET bottles like water or other drinking materials despite the fact that this product is of low toxicity. Several studies have shown that there is a small amount of migration but the concentrations of antimony in bottled water and the like are far below allowed maximum concentrations.

Antimony trioxide can also be used as a clarifying agent for glass, an opacifier for porcelain and enamel and a white pigment for paint. Its uses are quite varied. When it is used as a clarifying agent, it is added to the glass melt to remove bubbles from the solution. Many specialty glass companies use antimony trioxide for this purpose. Antimony oxide is a white crystalline powder so as a result it can be used as a white pigment for paint and as a white opacifier for porcelain and enamel.

SAM XU is a technologist with JIEFU.
JIEFU specializes in antimony trioxide and antimony based chemicals

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