GB958900A - Process for the production of glycidyl ethers of polyhydric phenols - Google Patents

Abstract

Glycidyl ethers of polyhydric phenols are prepared by etherifying the polyhydric phenol with epihalohydrin, using 2 to 15 moles of epihalohydrin per phenolic hydroxyl group of the phenol, in the presence of 90 to 98% of an equivalent of alkali metal hydroxide per equivalent of the phenolic hydroxyl group of the phenol; separating at least part of the unreacted epihalohydrin by passing superheated steam through the reaction mixture, and contacting the etherified phenol with alkali metal hydroxide in excess amount of that needed to react with the halogen in the ether on a chemical equivalent basis. The steam distillation may be effected using steam at 90-260 DEG C. and under pressures of 2 atmospheres or more down to 5 mm. Hg. In an example bisphenol is reacted at 100 DEG C. with 10 moles of epichlorohydrin by adding 1.9 moles of aqueous sodium hydroxide. The product is distilled at atmospheric pressure to remove some of the unreacted epichlorohydrin and then steam is passed through at a pressure decreasing from atmospheric to a reduced pressure to remove the remainder of the unreacted epichlorohydrin. The ether residue is then taken up in methyl isobutyl ketone, and then treated with aqueous sodium hydroxide, and then washed with sodium dihydrogen phosphate, and then recovered by removal of the solvent. In a comparative experiment, the removal of unreacted epichlorohydrin is effected by simple distillation. Specification 788,887 is referred to.ALSO:Glycidyl ethers of polyhydric phenols are prepared by etherifying the polyhydric phenol with epihalogohydrin, using 2-15 moles of epihalohydrin per phenolic hydroxyl group of the phenol, in the presence of 90 to 98% of an equivalent of alkali metal hydroxide per equivalent of the phenolic hydroxyl group of the phenol; separating at least part of the unreacted epihalohydrin by passing superheated steam through the reaction mixture and contacting the etherified phenol with alkali metal hydroxide in excess of that needed to react with the halogen in the ether on a chemical equivalent basis. The steam distillation may be effected using steam at 90-260 DEG C. and at a pressure of 5 min. Hg to 2 atmospheres. In an example, bisphenol is reacted at 100 DEG C. with 10 mols of epichlorohydrin by adding 1.9 mols of aqueous sodium hydroxide. The product is distilled at atmospheric pressure to remove some of the unreacted epichlorohydrin and then steam is passed through at a decreasing pressure. The ether residue is then taken up in methyl isobutyl ketone, and then treated with aqueous sodium hydroxide, washed with sodium dihydrogen phosphate and then recovered by removal of the solvent. Specification 788,887 is referred to.