| abstract |
The present invention relates to a process for producing a polypropylene sheet or film which comprises passing a molten sheet (3) or film of a polypropylene composition, the composition comprising polypropylene and at least one additive selected from the group consisting of a nucleating agent, a finely powdered high melting point polymer, a petroleum resin, a terpene resin, an organic peroxide and a crystalline propylene-based copolymer, between two cooling rolls (5A,5B) opposite to each other, the rolls being maintained at a temperature of 10 to 50 °C , and being subjected to specular finishing treatment , and adapted so as to convey therebetween a metallic endless belt (4) having a surface roughness of not more than 1.5 µm under tension , while carrying the sheet or film on the endless belt . |