Self-Coalescing Latex

Abstract

The present invention relates to self-coalescing latexes that incorporate film fat ing polymers that are low molecular weight polymers that are compatible with the latex and act as thin plasticizers penetrating through the remainder of the latex particle and aiding in the coalescence of the remaining polymers. In a preferred embodiment, the self-coalescing latex is a sequentially polymerized polymer having at least a core, a shell and a skin. The film forming polymers are formed of monomers substantially the same as the monomers of the shell but having average weighted molecular weights substantially less than the polymers of the shell. The present invention also relates to the method of polymerizing the self-coalescing latex of the current invention, which largely results from the addition of a substantial amount of chain transfer agent to a remaining portion, about 15% or less, of the monomer pre-emulsion prior to polymerization. Lastly, the invention relates to paint compositions incorporating the self-coalescing latexes that are substantially free of coalescing agents or aids.

Dependencies are inferred from the claim text.