ASA, the terpolymer of acrylon, styrene and axrylate, ASA, the terpolymer of acrylon, styrene and axrylate, is a new engineering resin which is developed against the disadvantage of ABS with bad weatherability. ASA molecular structure has no double bond but good weatherability. That is to say ASA can keep its physical property stability without coating even exposed in outdoor ultraviolet, damp, ...