| abstract |
A chromene compound which develops yellow to redncolor, a high color density and a little initial color andnwhich, when used in combination with an existingnphotochromic compound that exhibits blue color so as tondevelop a neutral tint, maintains uniformity in the colorntone at the time of developing color or fading color, ornexhibits a very large color fading rate. The chromenencompound has a naphthopyran cyclic skeleton, and isnexpressed by, for example, the following formula in whichna substituent such as substituted amino group ornmorpholino group is bonded to the sixth position of thennaphthopyran ring through a nitrogen atom, and two arylngroups having a particular substituent are bonded to thenthird position thereof,n nor |