| 摘要 |
PURPOSE:To obtain a nucleus for producing a pearl, having excellent physical strength, a specific gravity close to that of pearl, a pearl layer free from color unevenness, moldable in excellent dimensional accuracy even in a large spherical diameter, having excellent affinity for pearl, dense and uniform texture, improved hardness and coefficient of thermal expansion and no elution of harmful components with sea water. CONSTITUTION:[A] 100 pts.wt. of an unsaturated polyester resin comprising (1) 10-90 pts.wt. of an unsaturated polyester having >=3,000 number-average molecular weight and (2) 90-10wt.% of a monomer capable of dissolving the unsaturated polyester or an unsaturated oligomer having 500-2,000 molecular weight copolymerizable with the unsaturated polyester is blended with [B] 300-700 pts.wt. of an inorganic filler having >=2.5 specific gravity to give a resin composition, which is molded to give the objective nucleus for producing pearl. |
