Fluorescent Whitening Agent Tinopal® OB is a high molecular weight optical brightener of the thiophenediyl benzoxazole class, suitable for the optical brightening of polymers at all stages of processing. Tinopal® OB is highly effective in polymer substrates such as engineering plastics, e. g. polyesters, polycarbonate, polyamides and acrylics, thermoplastic polyurethane, polyvinylchloride, styrene homo- and copolymers, polyolefins, adhesives, and other organic substrates. Main applications include fibers, molded articles, films and sheets. Additional applications include clear lacquers, pigmented lacquers, paints, printing inks and synthetic leather. Tinopal® OB features excellent resistance to heat, exceptional whitening properties, good light fastness and low volatility. Tinopal® OB can be used as a tracer in a variety of applications.