Triaryl antimony compounds, oxidations,

Antagonism between antimony oxide and phosphoms flame retardants has been reported in several polymer systems, and has been explained on the basis of phosphoms interfering with the formation or volatilization of antimony haUdes, perhaps by forming antimony phosphate (12,13). This phenomenon is also not universal, and depends on the relative amounts of antimony and phosphoms. Some useful commercial poly(vinyl chloride) (PVC) formulations have been described for antimony oxide and triaryl phosphates (42). Combinations of antimony oxide, halogen compounds, and phosphates have also been found useful in commercial flexible urethane foams (43). 

Surprisingly, phosphorus when combined with bromine is effective in nonoxygen containing polymers. In another reference, a mixture of a brominated compound and a triaryl phosphate was claimed to be effective in HIPS where antimony oxide is generally required as a synergist for bromine (ref. 7). 

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