High Quality Phenolic epoxy resin CAS 61788-97-4

Generally speaking, the preparation method of epoxy resin can be summarized into two methods, one of which is to use compounds containing active hydrogen, such as compounds containing hydroxyl, carboxylic acid groups, amino groups, etc., as raw materials, under the catalysis of alkali, and Epoxy compounds (such as epichlorohydrin) are reacted and epoxy groups are introduced, such as the preparation of bisphenol A epoxy propyl ether epoxy resins. Compounds such as tetrahydrophthalic acid, cyclohexene, etc. are used as raw materials, and then peroxides are used to epoxidize the ethylenic bonds to form epoxy groups. For example, epoxy resins made by reacting with compounds containing ethylenic bonds are all This type. The synthesis of bisphenol A type epoxy resin varies with the relative molecular mass. The liquid epoxy resin with low molecular weight makes bisphenol A react with excess epichlorohydrin Chemicalbook alkane under the action of potassium hydroxide (sodium) to epoxidize it. In order to inhibit the formation of high molecular weight compounds and the hydrolysis of epichlorohydrin, lye should be added slowly. For epoxy resins with medium molecular weight, a one-step method is used. That is, bisphenol A (or other basic substance) is dissolved in sodium hydroxide, and then epichlorohydrin is gradually added to react. This method can save the amount of epichlorohydrin. For high molecular weight epoxy resins, there are two methods: one is the one-step method. Dissolve bisphenol A in sodium hydroxide, then add epichlorohydrin, and then add a part of sodium hydroxide, and finally dehydration and refining; the second is a two-step method, in which the epoxy resin is prepared and added Bisphenol A is allowed to react further to increase the relative molecular weight. This is because the epoxy resin has epoxy groups at both ends, which can react with Bisphenol A under certain conditions.