| 摘要 |
A 1,2-epoxyalkyl compound can be hydrolysed to the corresponding dihydroxy compound by (1) heating with aq. oxalic or malonic acid in the absence of air and under at least the pressure generated, and (2) distilling the mixture at a temperature sufficient to decompose the acid used. Preferably the epoxy compound is first mixed with an inert solvent such as an aromatic hydrocarbon on a ketone; this mixture contains 20-75%, esp. 35-50%, by wt. of the epoxy compound. Reaction is typically at 50 degrees-374 degrees C, for 15 min to 10 hours. The wt. of acid is 0.1 to 3%, esp. 0.5-1%, based on wt. of epoxy. The water concentration is 2 to 40, pref. 10 to 20 moles per mole of resin. Specifically the epoxy is the diglycidyl ether of bisphenol A. The hydrolysis is easily performed. conversion can be more than 99%. The acid catalyst is completely removed during the distillation and the hydrolysed product can be used without further purification as a diluent and a compatible additive for an epoxy resin which may be identical to the original starting material. In particular 1 to 20% by wt. of the hydroxy component is added. Main application of the mixture is as a coating or a paint vehicle. Addition of the hydroxy compound increases the speed of hardening of the epoxy resin and lowers the temp. required. The mechanical and chemical properties of the cured resin are not lowered by the hydroxy component and the shelf life of the uncured mixture is long. |
