Aromatic oxanilides

A number of classes of additives specifically for use as UV absorbers in polymer formulations are available including, among the better known ones, aromatic salicylates [11], o-hydroxybenzophenones [12], 2-hydroxyphenylbenzotriazoles [12,13], derivatives of cinnamic acid and related materials [14,15], aromatic oxanilides [16], cyclic imino ester derivatives known varionsly as benzoxazines or benzoxazones [17, 18] and hydroxyphenyltriazines [19]. 

Aromatic oxanilides may also dissipate absorbed energy by proton transfer, but this is less clear with these materials. There may also be a contribution from a simple screening effect because these additives have very high extinction coefficients in the region of 280-340 nm... 

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