M521C is an orthopthalic/NPG based, medium reactivity, high viscosity Unsaturated Polyester Resin. Gradual cure and optimized flexibility are the characteristics of this resin. M521C is specially formulated to be used in the production of button with rod casting method. It’s optimized curing and flexibility characteristics allow manufacturers sufficient time for further processing of the rods after they have been removed from the mould. It is compatible with water based dyes, polishing compounds, pearl essence and can be colored with pigment pastes. Very flexible and exhibits higher UV resistance compared to our other button grades.