The number of epoxy resin curing agent is divided into the explicit curing agent and the latent curing agent. The explicit curing agent is an ordinary curing agent; latent curing agent cooperates with epoxy resin under a certain temperature (25 ° c) long-term storage stability. When exposed to heat, light, and humidity, the curing reaction occurred. This kind of curing agent is basically to seal off its curing agent activity by use of physical and chemical methods.
Here are some types of epoxy resin curing agent.
In recent years, there are mainly 1,2- cyclohexylenediamine, 2-methylpentdiamine and 1, 3-pentdiamine. The epoxy curing agent can obviously improve the performance of coatings. But this type curing agent is generally more toxic, and the epoxide system of its deployment is high in heat, short in use and rigid in curing. The modified methods mainly include polyamine hydroxylation, polyamide ketamine, polyamine chlorethylation and an addition of polyamine and acrylate.
Imidazole Curing Agent
The performance of 2-methylimidazole curing agent is excellent, but it is inconvenient for the solid state. 2-ethyl-4-methylimidazole is liquid, but the price is higher. In recent years, modified imidazole was introduced in China, and 2-methylimidazole and other low molecular weight epoxy resins were used to destroy the chemical regularity of molecules, then liquefaction.
Acid Anhydride Type Curing Agent
The acid anhydride is widely used as the curing agent. In recent years, the chain enyl succinic anhydride and trimellitic anhydride have become the most popular curing agents. The chain enyl succinic anhydride is a liquid acid anhydride because its long linear alkenyl side chain greatly enhances the flexibility of the resin and reduces brittleness. It is suitable for Curing of epoxy resin for casting or laminating, epoxy resins dipping of electronic components. The cured epoxy resin of trimellitic anhydride has excellent heat resistance, electronic, mechanical properties and the drug resistance. And it also can significantly improve the brittleness of epoxy curing. It has been used for heat insulation board clamp and casting materials, heat resistant cable insulating paint, powder coating.
Catalytic Agent Curing Agent
Phosphine or phosphorus salts are increasingly used to replace amine as curing agents. They have more catalytic ability than amines, higher curing properties; In some cases, season salt is the only catalyst available. Therefore, season salt catalyst is the focus of the research and development of curing agent.
Latent Curing Agent
The latent curing agent is a necessary curing agent for many molding processes (epoxy molding, etc.). Latent curing agents commonly have the characteristics of room temperature storage stability and rapid curing. So it is widely used in various fields. For latent curing agents, they are mainly concentrated in the curing agent system to add the appropriate promoter.
We can see that functional curing agent has become a hot topic of research and development. Multi-functional curing agent becomes ideal products. Rapid curing, low-temperature curing and minimum suction rate of curing agent and electric property, mechanical properties, excellent mechanical properties of the curing agent develop rapidly. Some special functions of curing agents have also been developed. In addition, with the development of some new epoxy resin, the prospect of water-based epoxy resin and the supporting agent of the epoxy resin are also very good.
In recent years, the pressure of environment protection is increasing. People not only focus on the toxicity and environmental pollution in the process of production and use, they also and attaches great importance to the environmental pollution of the waste epoxy resin. So, one of the characteristics of the modern curing agent development is low toxicity and no toxicity. In developed countries, primary polyene and aromatic amine have been replaced by non-toxic or low-toxicity modified amines.
Most products of IRO are non-toxic or low toxic. As China coating additives manufacturer, we attach great importance to scientific research. We hope that we can have a further cooperation.