Abstract
Flexible sports protectors whose outer shells harden only under impact loading are proposed by virtue of the time dependency on elastic modulus due to the viscoelasticity. As an outer shell material, a bisphenol A-type epoxide resin with amine-based curing agent was selected because the mechanical properties can be controlled by changing the compound ratio of main and curing agents. The time dependency on elastic modulus was investigated by dynamic viscoelastic measurements. In addition, the performance as an outer shell was evaluated by drop weight impact test. The experimental results reveals that the soft epoxy resin is suitable as outer shell material for flexible protectors.
