If they can manufacture it for a reasonable price, there is a huge market in the medical community alone.
My wife has to wear a lead vest when she works in the OR. Even though she get the smallest one that will fit, it's still exhausting by the end of the day. A lightweight vest that provides protection and is cost competive with existing vests would be very popular everywhere x-rays are given. The material sounds like it'd be a lot better than lead lined walls in ORs and x-ray rooms, too.