Patent ID: 7638569

Claim:
An injection-molded gear made of a polyacetal resin composition comprising more than 5 and less than 100 parts by mass of a filler (II) and 0 or less than 10 parts by mass of an organic acid (III) based on 100 parts by mass of the polyacetal (I), characterized in that the filler (II) has a particle size distribution satisfying the following general expression and an average aspect ratio (L/D), i.e., a ratio of an average major-axis length (L) of the particles to an average minor-axis length (D) of the particles, of less than 3; and the gear comprises 10% or less of aggregates of the filler (II) having an aggregate diameter of 3 μm or more: 0.1 μm<D50<1.5 μm 0<( D 90− D 10)/ D 50≦2 (wherein D10, D50 and D90 represent particle diameters corresponding to cumulative particle size frequencies of 10, 50 and 90, in the order of increasing particle diameter, as measured by a laser diffraction scattering method).