POROUS FILM AND ITS PRODUCTION PROCESS

摘要

It is to provide a porous film which is excellent in gas permeability (air permeability) and moisture permeability (water vapor permeability), and is excellent in anti-leakage properties and anti-bleeding properties against a liquid, hiding properties and masking properties at an adhesion portion, and a process for producing it. A porous film obtained by melting and kneading a resin composition containing a polyolefin resin {component (A)} and a bulking agent {component (B)} as the main components, and a silicone {component (C)}, or a silicone {component (C)} and castor oil {component (D)}, followed by drawing, which shrinks by from 40 to 95% in one direction and expands by from 5 to 40% in a direction transverse thereto, when soaked in a silicone oil of 200 C for 60 seconds, and a process for producing the above porous film, are provided.