Curable Photochromic Compositions Including Hydrazide and Carbonyl Functional Components

A curable photochromic composition comprising:

• (a) a photochromic compound;
• (b) a hydrazide functional material comprising at least two hydrazide groups that are reactive with carbonyl groups selected from ketone groups and aldehyde groups;
• (c) a first carbonyl-functional component comprising a (meth)acrylate polymer having at least two carbonyl groups that are reactive with hydrazide groups, wherein each carbonyl group of said first carbonyl-functional component is independently selected from ketone groups and aldehyde groups;
• and
• (d) at least one of,
• (d1) a second carbonyl-functional component comprising at least one carbonyl group that is reactive with hydrazide groups, wherein said second carbonyl-functional component comprises at least one of polycarbonate carbonyl, polyester carbonyl, polyether carbonyl, polyurethane carbonyl, or combinations thereof, wherein each carbonyl group of said second carbonyl-functional component is independently selected from ketone groups and aldehyde groups;
• or
• (d2) a non-reactive component that is free of functional groups that are reactive with said hydrazide functional material, said first carbonyl-functional component, and said second carbonyl-functional component.