| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical reflector capable of preventing its color from being changed for a long period, without causing such discoloration as white polyester films conventionally change into yellow. SOLUTION: This optical reflector comprises a biaxially-drawn film containing a thermoplastic resin and a filler and having an opacity of≥95%, a whiteness of≥90%, a reflection factor of≥92%, and an areal draw ratio of 22-80, wherein the reflector has a color difference (ΔEH) of≤10 which is measured after irradiated at an irradiation intensity of 90 mW/cm<SP>2</SP>for 10 hr by using a metal halide lamp placed at a distance of 10 cm under an environmental condition of a temperature of 83°C and a relative humidity of 50%. COPYRIGHT: (C)2003,JPO |
