The ball-point pen, the production mannered null ceramic powder of the ceramic ball, and the ceramic

摘要

PROBLEM TO BE SOLVED: To improve satisfactory processability of giving precise sphericity in addition to wear resistance, corrosion resistance and mechanical strength, surface smoothness in the case of a product and writing characteristics by specifying surface roughness of a ceramic ball for a ballpoint pen. ;SOLUTION: The ceramic ball for a ballpoint pen is formed on its surface to have a width of 0.5μm or more, a depth of 0.2μm or more, a length of 10μm or more without a polishing damage within a region of 100μm², a centerline mean roughness of 4.5 to 10nm and maximum and minimum roughnesses of 50 to 100nm. On the surface of the ball, in an arbitrary range of 2,500m², polishing damages of a width of 0.5μm or more, a depth of 0.2μm or more and a length of 10μm or more are two or less. As the material of the ceramics adapted to the ball for the pen, suitable hardness and strength are required, and hence any of ceramics of alumina, silicon nitride and composite ceramic sintered material is suitable.;COPYRIGHT: (C)1998,JPO