Fillers for Use in Conjunction with Halogens

Organo-halides, especially bromides, are very effective fire retardants for most polymers. They work mainly by interruption of the gas phase combustion processes. This leads to incomplete combustion and high levels of smoke formation. 

It has been known for a long time that the efficiency of the halogenated flame retardants can be much increased by the use of certain additives, usually known as synergists. Most of these synergists are particulate inorganic fillers. Their main mode of action is believed to be the result of the formation of volatile metal halides. 

The main synergist in commercial use is antimony trioxide, which is believed to function by forming volatile antimony halides, which interfere with the gas phase 

Miyata, inventor Kabushiki Kaisha Kaisui Kagaku Kenkyujo, assignee EP 0 498 566A1,1992. 

Standard for Tests for Flammability of Plastic Materials for Parts in Devices and Appliances, 1996. 

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