| 摘要 |
PURPOSE:To improve a transparency, by a method wherein, in a T-die film extrusion-molding by use of rubber-reinforced arcylonitrile polymer, surface temperatures at the first drawing roll and the second drawing roll are maintained at the specified temperatures. CONSTITUTION:A copolymer, in which 50-95pts.wt. acrylonitrile and 50-5 pts.wt. acryl acid methyl are graft-polymerized, is extruded through a T-die under the existence of 3-30pts.wt. butadieneacrylonitrile copolymer containing 40- 95wt% butadiene. The copolymer so extruded is drawn in order in a condition that a surface temperature of the first drawing roll 4 is kept at a temperatyre of Tg- Tg+60 deg.C (Tg: glass transition point) of said copolymer, and a surface temperature of the second drawing roll at not higher than Tg. The first and second drawing rolls are caused to equalize in the drawing rate. |
