Lextran

UV Blocking Action from an Invisible Film

Lextran combines the desirable attributes of high optical transparency in the visible region and high opacity in the UV region. Its coatings are invisible and provide a durable protection from natural and artificial UV radiation.

The active ingredient of Lextran is a benzotriazole molecular switch which is remarkable for its UV absorption efficiency, low volatility and very low oral toxicity. Use of Lextran thus benefit from its outstanding eco-friendliness which eases the burden on disposal requirements.

The active material, solvent vehicle (ethyl lactate) and the acrylic binder are all environmentally benign. Lextran can be applied to a variety of substrates through spin, dip, roller or spray coating techniques.

The typical absorption spectrum of thin Lextran films is shown below on the left. The spectrum demonstrates the remarkable selective filtering action of Lextran for UV photons. The filtering action is more clearly seen in the transmission spectra on the right where the transmission of UV lamp light through bare glass (top) and Lextran-coated glass (bottom) is depicted. As can be seen, visible light is barely attenuated whereas UV radiation is completely absorbed.