| 摘要 |
PURPOSE:To improve the transparency, heat resistance and strength of a cassette half by using a blank material prepd. by adding an antioxidant in a prescribed range to a resin compsn. mixed with a specific block copolymer and an SMA resin in a prescribed range. CONSTITUTION:A resin compsn. which consists of a styrene/butadiene block copolymer contg. 5-50(wt.)% butadiene and a styrene/methyl methacrylate (SMA) resin having roughly the same refractive index as that of said copolymer, which contains 5-25% butadiene therein and in which the total content of a phenol and phosphite antioxidant with respect to said compsn. is 0.5-1.5% is used as a blank material. The transparency, heat resistance and strength of the cassette half are thus improved. |
