Effort to Evolve a Method of Eye Protection from Flash Blindness

摘要

Photochromics of the spirobi(naphthopyran) classes are shown to give significant improvements over present spiropyrans when used in practical eye-protection systems. In particular, the open-state luminous transmittance of the total system was increased to 67% while still retaining the capability of closing to a luminous density of approximately 3 within 100 micro sec. The photobleaching by visible light was negligible even at intensities corresponding to a nuclear weapon range at which the aircraft and crew could not survive. The preparation of a variety of new photochromics and the necessary intermediates is described. (Author)