| 摘要 |
PURPOSE: To obtain a biaxially stretched polypropylene film excellent in clarity, antiblocking properties, slip properties, and winding characteristics by dispersing a specific fine powder in a propylene polymer, forming the polymer into a film, and biaxially stretching it. CONSTITUTION: This film has a narrow-angle diffused transmission of 7.0% or lower, an antiblocking properties of 300g/20mm or lower, a coefficient of static friction of 0.40-0.80, and an air escape speed of 110sec or lower and is produced by homogeneously dispersing a fine powder in a propylene polymer, forming the polymer into a film, and stretching it in both the machine and cross directions. The fine powder used is selected from among an inorg. fine powder, a heat-resistant org. fine powder, and a fine thermoplastic resin powder virtually incompatible with the propylene polymer in the molten state and has a water drop-holding time (a time necessary for a water drop on the surface of the tune particle layer or the film to be absorbed by the layer to disappear) or 10sec or more. |
