Modified imidazole epoxy resin latent curing agent as well as preparation method and application

Abstract

The invention relates to a curing agent and particularly relates to a modified imidazole epoxy resin latent curing agent as well as preparation method and application. The curing agent is an imidazolemetal salt complex which is prepared by a reaction between 1-cyanoethyl-2-ethyl-4-methylimidazole and a transition metal chloride, wherein in the reaction, an alcohol compound is adopted as a solvent, and the reaction takes for 4-10 h at 60 DEG C; the solvent is removed by vacuum suction filtration and reduced-pressure distillation to obtain the product. The prepared curing agent and the epoxy resin have the characteristics of high compatibility, long room-temperature storage life and high reaction activity at high temperature; the epoxy curing product has good heat resistance and mechanicalproperty. The curing agent can serve as an epoxy resin latent curing agent and has a good application prospect in the fields of composite material production, adhesives, etc.

Description

technical field [0001] The invention relates to a curing agent, in particular to a latent curing agent for modified imidazole epoxy resins, a preparation method and an application. Background technique [0002] Epoxy resin is widely used in coatings, adhesives, composite material manufacturing and other fields due to its good heat resistance, mechanical properties, adhesion, electrical insulation and chemical corrosion resistance. Epoxy resin is generally a liquid or solid small molecule or oligomer at room temperature, and forms a thermosetting polymer material after a curing reaction with a curing agent. Epoxy resins can undergo curing reactions with a variety of curing agents, such as amines, acid anhydrides, mercaptans, phenols, phenolic and imidazole curing agents. Among them, imidazole curing agents are widely used in epoxy resin products because of their wide curing temperature, high curing efficiency, high modulus and good heat resistance of cured products. However...

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Problems solved by technology

However, unmodified imidazole curing agent and epoxy resin will slowly undergo curing reaction at room temperature, so this type of epoxy resin system usually needs to be transported and stored at low temperature, which increases the cost of materials and affects the durability of epoxy resin. Efficiency

[0003] At present, there have been some reports on the latentization of imidazole epoxy resin curing agents at home and abroad, including substitution modification (US4335228, CN106866937A), metal inorganic salt complexation modification (JApp Polym Sci, 1999, 75: 201-207) , microcapsule method (EP543675, CN101016369A), etc., wherein the imidazole curing agent obtained by the substitution modification method has good compatibility with epoxy resin, but its latency is still not ideal; metal inorganic salt complexation modified imidazole Although the curing agent can significantly improve its latent type, the imidazole after modification is generally solid and has poor compatibility with epoxy resin; However, during the preparation process of imidazole microencapsulation, there are many influencing factors, the reaction is not easy to control, and after the epoxy resin is cured, the microcapsule wall material remains in the epoxy resin system, which affects the stability of the material. physical properties

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