Melt-stable recyclable carbon black-laden polyacetal resin molding compositions and molded articles formed of the same

A method of making a melt-stable, recyclable polyacetal molding resin composition comprising the steps of:

• preblending carbon black with an ethylenic carrier polymer to form a carbon black-impregnated ethylenic polymer;
• and then
• melt-blending a polyacetal base resin with (A) said carbon black-impregnated ethylenic polymer for a time sufficient to disperse the carbon black homogeneously throughout the polyacetal base resin, and in an amount such that the carbon black is present in the composition in an amount between about 0.1 to 30 parts by weight, based on 100 parts by weight of the polyacetal base resin, and (B) a co-stabilization system which comprises (i) between 0.01 to 5 parts by weight of at least one compound selected from nitrogen-containing compounds, fatty acid ester compounds and metal-containing compounds having a hydroxide moiety, an inorganic acid salt moiety or a carboxylic acid salt of an alkali metal or an alkaline earth metal, and (ii) between 0.001 to 5 parts by weight of a hindered phenolic compound.