Optical brightener KSN and OB-1 have similar chemical structures, and Optical brightener KSN has better whitening effects on PC and plastics than OB-1, and its compatibility is also better than OB-1.Optical brightener KSN also has high temperature resistance. But it is also more light and weather resistant than OB-1. KSN is suitable for whitening PA, PAN, film, injection/extraction molds. Optical Brightener KSN Pure Powder 99%min with CAS No. 5242-49-9.