| 摘要 |
PURPOSE: Described are novel compositions of a carrier and at least two photochromic naphthopyran compounds. CONSTITUTION: The novel compositions of a carrier and at least two photochromic naphthopyran compounds are selected on the basis of specific criteria, that when exposed to solar ultraviolet radiation, exhibit neutral colors of gray or brown contained within the a* and b* ranges of +10 to -10 in the CIELAB color system. Also described are carriers, i.e., organic solvents and organic polymeric host materials, such as optically clear articles, e.g., ophthalmic lenses or other plastic transparencies that contain or that are coated with the naphthopyran compounds.
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