PURPOSE: To obtain a photochromic composition which develops halftones such as grey, amber and brown colors and undergoes no change in tone for a long time by combining a new fulgide or fulgimide compound with a chromene compound.
CONSTITUTION: This composition comprises 100 pts.wt. fulgide or fulgimide compound represented by formula I (wherein a group of formula II is a bivalent aromatic hydrocarbon or unsaturated heterocyclic group which may have substituents; a group of formula III is a norbonylidene, bicyclo[3.3.1]nonylidene or adamantylidene group which may have substituents; and X is oxygen, a group =N-R1 (wherein R1 is hydrogen, an alkyl or an aryl) or the like) and 0.01-10000 pts.wt. chromene compound. By further adding an ultraviolet stabilizer to this composition, the persistency of the photochromicity can be improved.
TANIZAWA TSUNEYOSHI
KOBAYAKAWA TAKASHI
