GB869830A - Preparation of vinyl stearate - Google Patents

Abstract

Vinyl stearate is extracted from a mixture comprising vinyl stearate and stearic acid by means of a paraffin hydrocarbon containing 7 or less carbon atoms, preferably below 15 DEG C., more preferably between about 0 and 5 DEG C. The vinyl stearate may be further purified by distillation and or treatment with calcium hydroxide or advantageously by treatment with a series of adsorbents comprising magnesium oxide, magnesium silicate and activated carbon, the stearate being preferably passed through the adsorbents. The vinyl stearate/stearic acid mixture is particularly that derived from a vinyl ester interchange reaction between stearic acid and a vinyl ester such as vinyl acetate in the presence of an interchange catalyst, particularly a mercury compound, e.g. a mercury salt strong acid, e.g. H2SO4, catalyst, which may also be present in the mixture extracted. The acid byproduct of the interchange is preferably removed before the extraction, e.g. by entrainment during the interchange reaction. The reaction mixture may also be neutralised, preferably with calcium hydroxide, although sodium acetate, magnesium silicate, magnesium oxide and calcium acetate are also mentioned, any precipitate removed, and volatiles also removed before the extraction. The stearic acid used to prepare the vinyl stearate may contain up to about 30% palmitic acid. Specifications 869,828 and 869,829 are referred to.