

Thermal Curing Application of Cycloaliphatic Epoxy Resin

There are many kinds of epoxy curing agents in common use and various curing ways (thermal curing, microwave curing, UV curing, etc.), but most of the specialty epoxy resins suitable for UV curing may not be suitable for thermal curing. Of course, there are products which are suitable for both processes, but such systems are relatively few, and cycloaliphatic epoxy resins are one of the examples.

The main thermal curing method of cycloaliphatic epoxy resin is anhydride curing

Commonly used anhydride curing agents include hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, chloroacetic anhydride, etc. It has little volatility, little toxicity, and little irritation to the skin. And it has a long operate time. Usually the curing speed of the anhydride type is slow, but the cured material is rigid.

Cycloaliphatic epoxy resin under anhydride system

Cycloaliphatic epoxy resin under anhydride system have the following characteristics.

① Higher compression and tensile strength.

② Good mechanical properties even under long-term exposure to high temperature.

③ Good arc resistance, UV aging resistance and weather resistance.

Epoxy anhydride system has been widely used in various fields of national economy because of its low viscosity, long operate life, low curing heat release, low shrinkage, high heat resistance and excellent mechanical properties . Usually, the curing speed of epoxy anhydride system can only be cured at high temperature. In electronic components encapsulating , high temperature will damage the components. Therefore, sometimes it is necessary to use catalyst to lower the curing temperature and accelerate the curing speed.

Accelerator can be very effective for thermal -curing

In the absence of accelerator, the hydroxyl group in the epoxy resin will opens the ring of the anhydride to produce monoester and carboxylic acid. In the presence of accelerator, the thermal curing speed of cycloaliphatic epoxy resin is also governed by the concentration of hydroxyl groups in the system. Therefore, the addition of accelerator is very effective for liquid epoxy resins, and the thermal curing reaction can be completed at 120-150°C for thermal insulation epoxy.

Application of cycloaliphatic epoxy resin in thermal-curing composite material

The cycloaliphatic epoxy resin are a low molecular compounds containing cycloaliphatic functions groups. They can be conversed a polymer with excellent performance of three-dimensional body structure after the reaction with curing agent.

The cycloaliphatic epoxy resins have good heat resistance, mechanical properties and weather resistance, with very low viscosity and long operating time, and are especially suitable for wet lamination and winding to manufacture high strength and heat resistant composites.

Applications of cycloaliphatic epoxy resin in heat curing mold manufacturing

Cycloaliphatic epoxy resins can also be used in plastic molds. With good heat-resistance, good mechanical strength, small volume shrinkage, high accuracy.

Cycloaliphatic epoxy resins are suitable for precision molds and molds. Compared with metal molds, it has the advantages of easy processing, low price, light weight, and convenient for molding operation.