| 摘要 |
<p>Packaging material for food and pharmaceuticals is based on copolymers, including graft copolymers, containing 70 - 98%, especially 78 - 98%, of methacrylonitrile and at least one vinyl aromatic such as styrene. Preferably the material is biaxially oriented. At 23 degrees C the oxygen permeability is lower than 0.005 cc/cm/24 hr./760 mm Hg/0.025 mm, and the water permeability is lower than 0.005 g/24 hr./cm/0.025 mm. The mechanical properties and the resistance to discoloration are good. USes are as films, bottles, containers, etc.</p> |
