| 摘要 |
Provided are: a polystyrene-based resin composition which has low water absorption, excellent suppression of warping or dimensional changes in a molded article, and excellent optical properties, and is suitable for producing a shaped light guide plate of excellent mold separation performance; and a light guide plate obtained by molding the polystyrene-based resin composition. This polystyrene-based resin composition contains 100 parts by mass of a styrene-based resin and 0.02 to 0.2 parts by mass of a phosphorus-based antioxidant, wherein the amount of 4-t-butylcatechol contained per 1 g of styrene-based resin is 1 to 6 μg. |
