PPG Patents Antimicrobial Coating

September 11, 2013

U.S. 8,258,202 B2
PPG Industries Ohio, Inc. has been granted a patent for a coating composition comprised of (a) a film-forming resin; (b) a porous solid comprised of an ion-exchange ceramic comprised of pores having antimicrobial metal ions disposed therein; and (c) a halogen ion-containing onium compound having a minimum molecular diameter according to the equation: D=2*((0.75*V)π)1/3 where D is the minimum molecular diameter and V is the van der Waals volume of the molecule, and the minimum molecular diameter is greater than the size of the pores having antimicrobial metal ions disposed therein, wherein (b) and (c) are present in amounts such that the composition, when applied onto a substrate and cured, provides a cured coating that exhibits UV color stability comparable to the UV color stability exhibited by the same composition that does not include (b) and (c), and wherein the halogen counterion-containing onium compound is a monomeric quaternary ammonium salt having the formula: R4N+X−, where each R is a hydrocarbon and each may be the same or different and X is a halogen atom.