| abstract |
The present invention relates to curable photochromic compositions which include a polycarbodiimide, an at least di-functional first carboxylic acid functional material having at least two carboxylic acid groups, an optional second carboxylic acid functional material having at least three carboxylic acid groups, a photochromic compound, and an aprotic organic solvent. The curable photochromic compositions have an equivalents ratio of carbodiimide equivalents of the polycarbodiimide to a total carboxylic acid equivalents of the first and optional second carboxylic acid functional materials of from 0.5:1 to 10:1 when the second carboxylic acid functional material is not present; and from 0.5:1 to 3:1 when the second carboxylic acid functional material is present. The present invention, more particularly, relates to curable photochromic coating compositions, and curable photochromic adhesive compositions. |