Polyacetal molded articles stabilized against discoloration

Abstract

Polyacetal molded articles are effectively stabilized against unwanted discoloration comprising by incorporating a synergistic combination of antioxidants selected from the group consisting of (i) Pentaerythritol tetrakis [3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate]; and (ii) At least one compound selected from the group consisting of tris-(4-t-butyl-2,6-dimethyl-3-hydroxybenzyl) isocyanurate, ethylene-1,2-bis-(oxyethylene(3-t-butyl-4-hydroxy-5-methylhydrocinnamate)), hexamethylene-1,6-bis-(3,5-di-t-butyl-4-hydroxyhydrocinnamate) and the monoacrylate ester of 2,2′-methylenebis(6-tert-butyl-4-methylphenol); or (iii) Hexamethylene-1,6-bis-(3,5-di-t-butyl-4-hydroxyhydrocinnamate); and (iv) At least one compound selected from the group consisting of ethylene-1,2-bis-(oxyethylene(3-t-butyl-4-hydroxy-5-methylhydrocinnamate)) and tris-(4-t-butyl-2,6-dimethyl-3-hydroxybenzyl) isocyanurate.

Dependencies are inferred from the claim text.