| 摘要 |
A polyoxymethylene composition which is improved in heat stability, i.e., inhibited particularly from forming mold deposit during molding and/or from discoloring during residence in a molding machine in a molten state, and is free from malfunction due to formic acid generating from the composition. The composition contains based on the polyoxymethylene (a) 0.01 to 3 wt.% of a sterically hindered phenol antioxidant, (b) 0.01 to 3 wt.% of a melamine/ formaldehyde polycondensate, (c) 0.001 to 0.5 wt.% of at least one metal compound selected from among oxides and carbonates of magnesium and calcium, and (d) 0.0001 to 0.05 wt.% of at least one boric acid compound selected from among orthoboric acid, metaboric acid, tetraboric acid and diboron trioxide. |
