Preparation method of nonionic waterborne epoxy curing agent

Abstract

The invention provides a preparation method of a nonionic waterborne epoxy curing agent, which comprises the following steps: (1) heating and dissolving epoxy resin and polyether polyol, evenly mixing, dropwisely adding catalyst at 50-130 DEG C to carry out polymerization reaction, and after the reaction finishes, dissolving the product in the epoxy resin and solvent to prepare a mixed solution; (2) while stirring, dropwisely adding a monoepoxy compound into basic amine, and reacting at 10-100 DEG C; (3) dropwisely adding the mixed solution in the step (1) into the reaction product in the step (2) at 30-120 DEG C, and enabling the reaction at 10-90 DEG C; and after the reaction finishes, diluting by adding water until the solid content reaches 30-80%, thereby obtaining the nonionic waterborne epoxy curing agent. The method has the advantages of simple technique and mild reaction conditions; the adopted cosolvent has the advantages of low toxicity or no toxicity, and low VOC (volatile organic compound) content; and the substance cured by the product has the advantages of favorable compatibility with epoxy resin and high toughness of the paint film.

Description

technical field [0001] The invention relates to a preparation method of a nonionic water-based epoxy curing agent. Background technique [0002] In recent years, waterborne epoxy coatings have developed rapidly. It is a kind of environment-friendly polymer material, which has many advantages such as low organic solvent content, low odor, chemical resistance, insulation, etc., and has a wide range of uses and application prospects. Curing agent is one of the key factors affecting the performance of two-component epoxy coatings, and is a key component that determines the product process technology and characteristics. Ordinary aliphatic amine room temperature curing agents are more irritating to the human body, and are easy to react with carbon dioxide in the air to form salts or absorb moisture and become white. Therefore, most of the water-based epoxy curing agents that are cured at room temperature in practice use their modified products, including amidated polyamines, pol...

AI Technical Summary

Problems solved by technology

[0004] In the preparation process of the water-based curing agent involved in the US6277928 patent technology, the amine is excessive, and the excess amine needs to be removed after the reaction is completed, and the energy consumption is high; and toxic solvents such as toluene are added during the reaction process. Some solvents need to consume energy, on the other hand, the production process is not environmentally friendly

[0005] CN 101007863 discloses a preparation method of non-ionic water-based epoxy curing agent, but in the chain extension reaction of its preparation process, amine is a large amount of excess, and a large amount of solvent is added in the reaction process, and the excess must be removed after the reaction is completed. amines and solvents, on the one hand, the boiling point of amines is high, and it requires high temperature and high energy consumption to remove excess amines; on the other hand, during the removal process, amines and solvents cannot be completely separated; Add a large amount of solvent in the reaction, after the reaction is completed, it is necessary to carry out desolvation by distillation under reduced pressure

The whole process is more complicated and consumes more energy