Refractive Index of Resin:
The resin to be measured was subjected to extrusion molding to obtain non-oriented films having a thickness of 20 ์m. The refractive index of the resultant films was measured using an Abbe refractometer (4T Model from Atago Co., Ltd.,
SL-Na-1 Lamp from Toshiba Corp.). The temperature of the resin being extruded was 210ฐ C. when the resin was EVOH, 260ฐ C. when the resin was polyamide, 160ฐ C. when the resin was polyvinyl chloride, and 200ฐ C. when the resin was polyacrylonitrile.
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