| abstract |
A foamable aqueous composition is used to form foamed, opacifying elements with one or more dry foamed layers. The composition contains: (a) 0.5 to 20 weight % of porous particles comprising a continuous polymeric phase and discrete pores dispersed within the continuous polymeric phase. The porous particles have a mode particle size of 2 to 50 ยก.tm; (b) at least 20 weight % of a binder material; (c) 0.1 to 30 weight % of a combination of various additives including dispersants, plasticizers, inorganic or organic pigments and dyes, flame retardants, biocides, fungicides, optical brighteners, tinting colorants, metal flakes, and inorganic or organic fillers; (d) water; and (e) at least 0.001 weight % of an opacifying colorant different from (c). The foamable aqueous composition is suitably aerated, disposed on a porous substrate, dried, and crushed on the porous substrate to form a foamed, opacifying element. |