US Patent 11932744 Light-blocking articles from foamed composition containing solid polymeric particles

A foamed, opacifying element has a substrate with opposing planar surfaces and a foamed opacifying layer disposed on one opposing surface. The foamed opacifying layer contains (a) 0.1-80 weight % of nonporous polymeric particles; (b′) 10-80 weight % of a matrix material derived from a (b) binder material having a glass transition temperature of less than 40° C.; (c) 0.0001-50 weight % of certain additives; (d) less than 5 weight % of water; and (e) at least 0.002 weight % of an opacifying colorant different from all of the (c) additives. Foamable and foamed aqueous compositions can be used to provide these foamed, opacifying elements for use as light-blocking window shades, curtains, or other materials. These light-blocking articles can also have a printable outer surface that accepts ink for making printed images that are not observable from the opposite surface.