B-Stage Epoxy Systems
Many high performance epoxies can be formulated as B-stage systems. A B-stage epoxy is a system wherein the reaction between the resin and the curing agent/hardener is not complete. Due to this, the system is in a partially cured stage. When this system is then reheated at elevated temperatures, the cross-linking is complete and the system fully cures.
There are many advantages to using a B-stage system. The need for measuring and mixing is eliminated since this is a one part system. In many cases, B stage epoxies help to increase the performance of the product and decrease the overall manufacturing/production cost. Also, B-stage systems can be more convenient to use than a two part epoxy system in many applications.
Some of Master Bond’s B-stage systems are: EP36 and EP36CLV. Master Bond also offers thermally conductive B-stage systems like EP36AO. They are used mainly in potting, encapsulation and casting applications. These one part systems liquefy at about 180°F when they are subjected to a gradual ramp up in an oven. They can be cured at temperatures ranging from 250-350°F and higher. Some salient properties of these systems are:
- Excellent toughness coupled with great resilience properties
- Excellent resistance to high temperatures and thermal cycling/shock
- Good electrical insulation properties with high dielectric strength
- High thermal conductivity (only for EP36AO)
