| abstract |
Glycidyl ethers of monohydric or polyhydric phenols of high purity are obtained if hydrogen halide is eliminated from halohydrin ethers of the phenols in aqueous alkalis in the presence of one or more onium compounds selected from quaternary ammonium compounds having at least one aliphatic C4-22 hydrocarbon radical, quaternary phosphonium compounds and tertiary sulphonium compounds as catalyst, or in the presence of those compounds which form in the reaction medium in situ, before the addition of the alkali, such onium compounds from the halohydrin ethers together with tertiary amines, tertiary phosphines or thioethers. In comparison with the known processes, the rate of dehydrohalogenation can thereby be significantly increased as a result of which an increase in production is achieved. Moreover, significantly purer reaction products are obtained by the avoidance of side reactions. The glycidyl ethers may be used as low-viscosity casting and coating resins in the form of coatings, adhesives, moulding materials, etc., and conventional hardeners can be employed. Due to their low viscosity the workability of the glycidyl ethers is considerably better and the capacity to absorb filling materials is greater. The extremely low content of easily saponifiable halogen results in an especially favorable corrosion behavior. |