Method of preparing polyaspartic ester

Abstract

The invention discloses a method of preparing polyaspartic ester. The preparation method comprises the following steps: (1) organic primary amine and unsaturated dibasic acid ester are subjected to Michael addition reaction under the catalysis of a supported Lewis acid catalyst, and (2) a catalyst and excessive unsaturated dibasic acid ester are removed from the reaction solution obtained in the step (1) to obtain polyaspartic ester, wherein the supported Lewis acid catalyst comprises 40-60 wt% of indium trifluoromethanesulfonate, 10-30 wt% of one or more of indium chloride, copper trifluoromethanesulfonate, aluminum trifluoromethanesulfonate and zinc trifluoromethanesulfonate, and the balance of a carrier, and the content is based on the total weight of the catalyst. Raw materials of thecatalyst are common and easy to obtain, the preparation method is simple and convenient, and the method has the advantages of good catalytic activity, high primary amine conversion rate, simplicity and convenience in operation, high product quality and the like when used for preparing polyaspartic ester.

Description

technical field [0001] The invention belongs to the field of organic chemical synthesis, and in particular relates to a method for preparing polyaspartate. Background technique [0002] Polyaspartic Acid Ester (PAE) is synthesized by Michael addition reaction of diamine and maleic acid ester, and compounded with low viscosity isocyanate curing agent to obtain polyaspartic acid ester polyurea , known as the third-generation polyurea, due to the steric hindrance and inductive effect of the ester group in polyaspartate, and through structural design, its gel time can be adjusted from minutes to hours. As a new type of high-performance material, PAE polyurea has the advantages of high solid content, ultra-fast drying, and no need for catalysts compared with traditional polyurethane materials. It is widely used in related fields with high quality requirements for anti-corrosion, waterproof, wear-resistant and weather resistance. . [0003] It is well known in the art that the r...

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Problems solved by technology

Chinese published patent CN109320681 reports that the conversion rate of primary amines is improved by introducing acrylate in the late stage of the reaction, and the primary amines can be quickly eliminated through the introduction of highly active electrophilic groups; Chinese published patent CN102250343A reports the use of supported alkali metal fluorine Compound catalyzed method for synthesizing polyaspartate, the reaction rate has been improved, but in the later stage of the reaction, glycidyl tertiary carbonic acid ester needs to be added to further improve the conversion rate; Neither of them directly increased the conversion rate of primary amines to single electrophiles.

Overall, the methods reported in these literatures have improved the conversion rate of primary amines to a certain extent, but there are still problems such as the inability to directly increase the conversion rate of primary amines, the slow reaction speed, the high color of the product caused by high reaction temperature, and the use of the method. There are many problems such as limitations, unsatisfactory

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