Patent ID: 6294632
Filing Date: 2001-09-25
Classification: B29C,B29D,B29K,C08J

Abstract:
A biaxially oriented polypropylene film which has a melt flow rate (MFR) of from 1 to 12 g/10 min and in which the melt viscosity .eta.0, as measured with a rotational rheometer at a shear rate of 0 rad/sec, the melt viscosity .eta.10, as measured with the rheometer at a shear rate of 10 rad/sec, and the MFR satisfy the relationshiplog[(.eta.0-.eta.10)/.eta.10]+0.7logMFR.ltoreq.0.7wherein the biaxially oriented polypropylene film has a half-crystallization time at 120.degree. C. of from 80 to 200 seconds as measured with a crystallization rate analyzer based on depolarization intensity and a density of from 0.890 to 0.920 g/cm.sup.3.