DE2028136

1278737 Polyglyidyl ethers SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ NV 8 June 1970 [10 June 1969] 27501/70 Heading C3B Polyglycidyl ethers of polyhydric phenols are prepared by a three step process: (i) epichlorohydrin (I) is reacted catalytically with polyhydric phenol (II) in a molar ratio of at least 1.5 : 1 (I : II), in a substantially anhydrous medium until at least 5% (preferably at least 80%) of the phenolic OH groups have been etherified, (ii) the product is dehydrochlorinated with 0À80-0À99 equivalents of alkali per equivalent of II in the presence of excess I during which water is azeotropically distilled, (iii) remaining I is distilled off in the presence of excess alkali in relation to the quantity of saponifiable chlorine still present. II may be bisphenol A. Suitable catalysts for the first stage are tertiary amines, tertiary phosphines or organic sulphides, or quaternary ammonium, phosphonium or sulphonium compounds, e.g. tetramethylammonium chloride. From 0À5-5 mol. per cent of catalyst may be used based on the phenol. The reaction temp. in the first stage may be 90- 130‹ C. In the second stage an aqueous soln. containing at least 45% by wt. NaOH or KOH may be used in the third stage a 2-20% by wt. alkaline soln. may be used to provide a 5-15 fold excess of alkali. Excess I may be removed under vacuum at 100-180‹ C. The by-product salt may be removed by dissolving the resin formed in an inert solvent and washing with water. Alternatively it may be removed by filtration or centrifuging. The products are low mol. wt., e.g. products from bisphenol A have epoxide equivalents of 182-198.