Optical Brightener OB Chemical name: 2,5-bis(5-tert-butyl benzoxazolyl-2-)thiophene Structure: Formula: C26H26N2 O2S Molecular Weight: 430 C.I. Number: 184 Appearance: slight yellow or milk white powder Melting Point: 200~202?#1057; Purity: >99.0% Application: mainly be used in whitening of thermoplastic, polyvinyl chloride (PVC), polypropylene (PP), polyester fiber, paint and ink, etc. Packing: 25kg per fiber drum