Fluorescent brightener 184, or called OB (CAS# 7128-64-5), is a kind of top grade optical brightener suitable for many kinds of plastics, such as thermal plastics and thermal setting plastics like PVC, PE, PP, PS, ABS, PMMA, POM, polyester fiber. Especially suitable for polyolefin, polyamide, and polyacrylonitrile. It is widely used in film, injection molding and extrusion molding materials, suitable for all plastic processing.