Spectral sensitizers for photochromic - spiropyrans

摘要

Sensitisers for rendering photochromic spiropyrans which are normally sensitive to rays of wavelength 360 nm sensitive to visible light rays of wavelength 400-500 nm are chosen from diacetyl, 1,2-dihydroxyanthraquinone, 1,5-dihydroxyanthraquinone, and certain chelates of benzoyl acetone esp. N benzoyl acetonate, terbium tribenzoylacetonate or terbium sodium tetrabenzoyl acetonate. The pref: amount of sensitiser is 2.5-5 times that of the spiropyran. After sensitisation the spiropyrans are used in the mfr. of interpolated layer of glazed laminates esp. those contg. polyvinyl butyrate.