Polyaspartate, and preparation method and application thereof

Abstract

The invention discloses a polyaspartate, and a preparation method and application thereof. The preparation method comprises the following steps: (1) reacting maleic anhydride with an epoxy monomer to obtain maleic acid glycol ester; and (2) reacting the maleic acid glycol ester obtained in the step (1) with primary amine to obtain the polyaspartate. After the polyaspartate and an isocyanate curing agent are mixed to obtain a polyaspartate polyurea coating. Maleic anhydride is modified with the epoxy monomer to synthesize maleic acid glycol ester, and then maleic acid glycol ester reacts with the primary amine, so that polyfunctional polyaspartate can be prepared, and the mechanical property of the coating is improved; and the synthesized maleic acid glycol ester has no trans structure, the acid value of the product is low, the viscosity of the prepared coating is slowly increased, and the construction permeation is facilitated.

Description

technical field [0001] The invention relates to the field of polymer synthesis, in particular to a polyaspartic acid ester and its preparation method and application. Background technique [0002] Polyaspartic acid ester resin is a special kind of steric hindered secondary amine compound. Its steric hindrance and inductive effect work together to reduce the activity of secondary amine when it reacts with -NCO. Compared with traditional polyurea materials, It has longer construction time and higher paint film adhesion. Polyaspartic ester resin is combined with aliphatic isocyanate curing agent, and the prepared polyaspartic ester polyurea coating has excellent mechanical properties and aging resistance, which is more excellent than general hydroxyl resin and epoxy resin. drying speed. [0003] Polyaspartic acid esters in the prior art are generally obtained through the reaction of dialkyl maleate and fatty primary amines, and dialkyl maleate is prepared by esterification of...

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Problems solved by technology

[0004] Yet adopt the method in the prior art, there is following problem when preparing the reaction raw material dialkyl maleate of polyaspartate: 1, when maleic anhydride reacts with alcohol, the esterification temperature is high, easily produces trans The structure is not conducive to the subsequent reaction with primary amines, resulting in insufficient conversion of primary amines, so when used in coatings, the early viscosity increases rapidly, and the construction operation time is short; and the product is easily oxidized at high temperature, which affects product quality; 2. Maleic anhydride Esterification with alcohol is difficult, accompanied by reverse reaction, the synthesized dialkyl maleate has a high acid value, and when the polyaspartic acid ester made from it is used in coatings, it is easy to react with isocyanate curing agent to generate carbon dioxide. The coating is easy to generate bubbles, and the coating performance is not good; 3. When maleic anhydride and alcohol are esterified, the solvent needs to be removed with water, which is not environmentally friendly; 4. The polyaspartic acid synthesized by the method in the prior art Most of the ester resins are two-functional resins, and the ratio range of the curing agent and the curing agent is narrow. The mechanical properties of the cured coating are not good, which is not conducive to the use of coatings.

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