| abstract |
(57) [Summary]nNovel reversible photochromic 2H-naphtho [1,2-b] pyran compounds are disclosed. Examples of such compounds include compounds having a specific substituent at the 5-position carbon atom of the naphtho moiety of naphthopyran and the 2-position of the pyran ring. Certain substituents may be attached to the 6-, 7-, 8-, 9- or 10-position carbon atom of the naphtho moiety of the naphthopyran. Organic host materials containing such compounds or coated with such compounds are also disclosed. Further, articles containing such a novel naphthopyran compound or a mixture of the naphthopyran compound and a complementary photochromic compound (for example, a spiro (indoline) type compound or the like), for example, ophthalmic lenses and other transparent plastics An article is also disclosed. |