A preparing method of hydantoin epoxy resin

Abstract

The invention relates to a preparing method of hydantoin epoxy resin. The method adopts 5,5-dimethylhydantoin and epichlorohydrin as raw materials, adopts a quaternary ammonium salt as a ring-opening catalyst, and includes heating and reacting under nitrogen protection, cooling, gradually adding a calculated amount of granular sodium hydroxide as a ring-closing catalyst in batches with a lower aliphatic ketone or tetrahydrofuran being adopted as a solvent, subjecting materials to suction filtration when the solvent exits to remove a part of sodium chloride granules, transferring filtrate to a distillation device, performing vacuum distillation, transferring a product out of an evaporator when the volume is reduced by about a half and a salt separates out, performing suction filtration to remove the salt, performing a plurality of times of vacuum distillation and suction filtration until no salt separates out through observation from the materials in vacuum distillation, and performing vacuum distillation until no solvent is evaporated in 1-5 min so as to obtain a product. The method is advantageous in that the method can effectively remove sodium chloride granules which are a by-product in a preparing process, thus reducing the content of inorganic chlorine in the product and improving product quality.

Description

technical field [0001] The invention relates to a method for preparing a low-polymerization epoxy resin product, in particular to a method for preparing a hydantoin epoxy resin, and belongs to the field of organic chemical raw material manufacturing. Background technique [0002] Hydantoin is a five-membered heterocyclic compound containing two nitrogen atoms, and it is a substance with a non-benzene ring nitrogen heterocyclic structure. Hydantoin epoxy resin formed from it and epichlorohydrin etc. is not flammable and has low smoke emission even when burned. Hydantoin epoxy resin has good solubility in water when it is not cured, and it also has excellent mechanical properties, thermal stability and good process performance. After it is cured with acids, aldehydes, amines, and imidazoles, the cured product has a small shrinkage rate and good crack resistance under the environment of temperature changes, so it has good heat resistance and weather resistance. The materials ...

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Problems solved by technology

When epichlorohydrin is in contact with alcohols with active hydrogen for a long time under alkaline conditions, it may convert epichlorohydrin into alcohol ethers, which leads to the complexity of the reaction and makes the recovery of epichlorohydrin Propane becomes difficult, increasing unit consumption of production

In addition, in the case of precipitation to constant weight and high viscosity of the product, it is doubtful whether the by-produced, fine sodium chloride particles dispersed in the resin can be basically filtered out

And even if it is said in this method, light yellow solid or liquid is obtained after precipitation and filtration, it also shows that the molecular weight and viscosity of the obtained product are too large, and the superiority of hydantoin epoxy resin has been lost, so it is difficult to Downstream is well applied

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