AQUEOUS BARRIER COATING COMPOSITION WITH KAOLIN CLAY FILLER AND ACRYLIC MATRIX POLYMER

摘要

An aqueous barrier coating composition in the form of a dispersion consisting of : (a) water; (b) an acrylic matrix polymer; (c) a platy to hyperplaty kaolin filler having an average shape factor of at least 40:1, the filler being pre-treated with acid prior to being combined with the acrylic matrix polymer, the composition optionally including a disperdant and/or a thickener and being further characterized in that: (i) the composition has a solids content of from 20 to 70 percent by weight; (ii) the composition has a weight ratio of acrylic matrix polymer: kaolin filler of from 4:1 to 0.75:1; and (iii) a film formed from the composition exhibits at least 25-fold reduction in oxygen permeability as compared with a like film formed of said acrylic matrix polymer.