Patent ID: 7041307

Claim:
A biocidally active polymer composition resistant to discoloration which comprises a melt blend of (I) a polymer substrate, and (II) an effective biocidal amount of a biocide-polyester concentrate, wherein the polymer substrate is a polyolefin, polystyrene, polyamide, polycarbonate, a polystyrenic, a polyurethane, an acrylate polymer, a polyacrylonitrile, a rubber modified styrenic polymer, poly(vinyl chloride), poly(vinyl butyral) or a polyacetal, which concentrate comprises 10–50% by weight of a biocide and 90–50% by weight of a polyester selected from the group consisting of poly(ethylene terephthalate) PET, poly(ethylene 2,6-naphthalene-2,6-dicarboxylate) PEN and poly(ethylene/1,4-cyclohexylenedimethylene terephthalate) PETG copolyester, where the biocide is 0.01 to 5% by weight based on the total composition and wherein the biocide is (a) 2,4,4′-trichloro-2′-hydroxydiphenyl ether.