A METHOD OF INCREASING THE LIGHT FATIGUE RESISTANCE OF A PHOTOCHROMIC COMPOSITION AND PHOTOCHROMIC COMPOSITION

摘要

An organic photochromic composition comprises spiro [indoline-2,3'- [3H] -napht [2,1-b] [1,4] oxazine] dye (spirooxazine dye) and unconventional ultraviolet stabilizers. The ultraviolet stabilizers provide for a good light fatigue resistance of the spirooxazine (S.O.) dye and will not hinder the photocolorability of the photochromic composition. The unconventional ultraviolet stabilizers belong to the class of hindered amine light stabilizers (HALS) and excited state quenchers.