Thermally stable polyoxymethylene compositions

A polyoxymethylene composition consisting essentially of:

• (a) 95.85 to 99.94 weight percent polyoxymethylene polymer,
• (b) 0.4 to 0.6 weight percent of an amine polymer selected from the group consisting of polyacrylamides, polyallylamines, polyacrylic hydrazide, polymethacrylic hydrazide, polyaminoalkyl acrylate, polyaminoalkyl methacrylate, poly vinylalkylamine, and mixtures of these;
• (c) 0.008 to 0.08 weight percent of a polyamide having a melting point of about 140° C. to about 240° C. and wherein said melting point ranges between 40° C. below the melting point of (a) to 40° C. above the melting point of (a), and
• (d) 0.01 to 4.0 weight percent of an antioxidant, wherein the polyoxymethylene composition, when molded, exhibits:
• a tensile creep to 10% strain at 90° C. and 25 MPa pressure of at least 0.32 minutes, as determined according to ASTM D2990;
• a time to mold deposit of at least 12 hours;
• and
• a thermally evolved formaldehyde of less than 0.50 percent, as measured at 250° C. for a period of 0.5 hours.