BIAXIAL ORIENTIERTE POLYPROPYLENFOLIE MIT ERHÖHTER DIMENSIONSSTABILITÄT

摘要

Biaxially oriented polypropylene (PP) film comprises base ply (or plies) contg. PP having the following properties: (i) a mean isotactic block length of the PP mol. between 2 structural chain defects of, as statistical average, greater than 40; (ii) chain isotactic index for n-heptane-insol. fraction of PP of at least 95%, measured by means of <13>C-NMR spectroscopy; (iii) ratio of wt. average Mw to the number average Mn of the mol. wt. distribution of less than 4; (iv) an n-heptane-soluble fraction of PP of less than 1%; and (v) film shrinkage in the longitudinal direction and in the transverse direction of less than 5%. Also claimed are: (a) a process for the prodn. of the above PP film; (b) the use of the PP film as a packaging film ; (c) the use of the PP film as a laminating film.