Composite film and utilization thereof

摘要

A composite film comprising a first layer comprising a polyolefin resin containing finely divided calcium carbonate dispersed therein and a surface layer comprising a polyolefin resin containing an acidic filler dispersed therein, which surface layer is bonded directly or indirectly to at least one surface of the first layer and has a thickness of at least 3 microns. A diazo copying paper is also disclosed which has a photosensitive diazo layer on the surface layer of the composite film.