GB1277668A - Improved method of making glycidyl ethers - Google Patents

Abstract

1277668 Glycidyl ethers REICHHOLD ALBERT-CHEMIE AG 22 Dec 1969 [8 Jan 1969 29 Oct 1969] 62199/69 Heading C3B [Also in Division C2] Glycidyl ethers of monohydric phenols are prepared by reacting the phenol with an excess of epichlorohydrin in the presence of 0À95-1À15 of an equivalent of alkali metal or alkaline earth metal hydroxide per equivalent of phenolic hydroxyl. The process comprises the following steps: (i) 10-90% of the alkali metal or alkaline earth metal hydroxide is added in the solid state in 30-90% of the total addition time which amounts to 30-300 minutes. Reaction heat is removed by reflux distillation under reduced pressure in the presence of water of reaction and added water of 0À3-6À0% by wt. based on the epichlorohydrin. (ii) 90-10% of the alkali metal or alkaline earth metal hydroxide is added in the remainder of the addition time; the reaction heat and water are removed by azeotropic distillation under reduced pressure and the water free phase containing epichlorohydrin is returned to the reaction vessel. (iii) Excess epichlorohydrin is distilled off under reduced pressure. The glycidyl ether formed is isolated by filtration or dissolution. The product is washed with water to separate alkali metal or alkaline earth metal chloride and the solvent (if any) is removed. The preferred hydroxide is NaOH. The reaction may be carried out in the presence of 3-25% of an aliphatic alcohol of limited solubility in water and/or 3-25% of aromatic solvents (based on the epichlorohydrin used). From 1-10% by wt., with respect to the glycidyl ether, of an aqueous (1-20% by wt.) H 2 O 2 soln. is made to flow into the liquid glycidyl ether at 100- 180‹ C. with stirring and at the same time excess H 2 O 2 and volatile constituents are removed by distillation. Examples relate to the preparation of glycidyl ethers of bisphenol A, bisphenol F and a mixed diglycidyl ether of bisphenol A, resorcinol and a phenol novolac.