Prepn. of light polarising organic per-halide cpds. - for use in suspension in light valves

摘要

A light polarizing material comprises a per halide of an organic cpd. and is suspended in a liq. for use in light valves. The per halide is prepd. by hydrogenating an organic cpd. with unsatd. branch chain; forming a salt of the resulting satd. cpd. and forming a perhalide of the salt. The suspension is stable to degradation by heat and by lower alcohols and ether-alcohols as opposed to the prior art cpd. herapathite. Pref. unsatd. organic cpds. are alkaloids e.g. quinine and cinchonidine. After hydrogenation the satd. cpd. is reacted with an acid e.g. H2SO4 on a polybasic or hydroxy organic acid to form the salt. This is then reacted with a halide and halogen to form the perhalide.