| 摘要 |
PURPOSE:To provide both lubricity and adhesiveness, which are generally contradictory properties, and obtain a feed-improving layer with a favorable film-forming property, by causing the feed-improving layer to comprise a graft copolymer having a polymer excellent in release properties and lubricity as a side chain and a polymer excellent in adhesiveness and film-forming properties as a backbone chain. CONSTITUTION:A feed-improving layer provided on the upper side of a base film comprises a graft copolymer having a polymer excellent in release properties and lubricity as a side chain and a polymer excellent in adhesiveness and film-forming properties as a backbone chain. The polymer excellent in release properties and lubricity is preferably a polymer having a critical surface tension of not more than 22 dyne/cm and a frictional coefficient of not more than 0.3. The polymer excellent in adhesiveness and film-forming properties is preferably a polymer having a critical surface tension of not less than 37 dyne/cm. In order that the backbone chain moiety, e.g., an acrylic polymer moiety and the side chain moiety, e.g., a silicone polymer moiety display the respective characteristics thereof, they are preferably used in a weight ratio of 2:0.5-1:3.5. The thickness of the feed-improving layer is preferably 0.1-1.5 mum. By this, release properties and lubricity are developed. |
