BIAXIALLY ORIENTED SHEETING FOR ELECTRICAL INSULATION WITH IMPROVED SHRINKAGE AT ELEVATED TEMPERATURES

摘要

A biaxially oriented polypropylene film is described. The n-heptane-insoluble content of the film has a chain isotacticity index, measured by 13-C-NMR spectroscopy, of at least 95%. In particular, the film should have the lowest possible shrinkage (transverse shrinkage and longitudinal shrinkage) at elevated temperatures. In addition, a process for the production of the polypropylene film and its use is described.