SHEET AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To efficiently produce a sheet not having possibility such that an uneven part is damaged or contaminated and having an uneven surface therewithin. SOLUTION: A thermoplastic resin sheet 1 having an uneven surface formed therewithin is constituted by laminating a first light pervious resin layer A having an uneven surface formed on at least one surface thereof at a constant uneven pitch and a second resin layer C covering at least the uneven surface and noncompatible with the first resin layer. A co-extrusion cap apparatus having a main passage for forming the uneven surface to the first resin layer A and a sub-passage for forming the second resin layer C covering at least the uneven surface and non-compatible with the first resin layer is used to subject respective resins to coextrusion.