| 摘要 |
PURPOSE: To obtain a nucleus material for pearls, especially high in specific gravity, free from color irregularity, having a transparent milky white color, excellent in mechanical strength, and excellent in affinity to pearl mother shellfish. CONSTITUTION: This molding material composition suitable for producing nuclei for pearls comprises [A] 100 pts.wt. of a polyester resin having a Hazen color number of 5500 in a melted state or in a liquid state, [B] 200-600 pts.wt. of barium sulfate having a primary particle average diameter of <=0.5μm, and [C] 0.1-200 pts.wt. of at least a polysaccharide selected from the group consisting of starch, dextrin and glycogen.
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