| abstract |
(57) [Summary] (Modified) [Structure] In the polymerization of polypropylene, the amount of polypropylene obtained is 300,000 g based on titanium in the catalyst. / G-Ti or more, the ash content obtained by complete combustion is 40 weight ppm or less, titanium is 1 weight ppm or less in the ash composition, and the chlorine content in the polypropylene is 2 weight ppm or less, A polymer insulating material having a boiling n-heptane-soluble content of 1% by weight or more and 10% by weight or less, and an inorganic oxide or hydroxide having an average particle size of 1 μm or less and an organic material in which the polypropylene does not include a particle size of 10 μm or more. It is a polymer insulating material in which polysilane, maleic anhydride grafted polypropylene, and a silane compound having an organic polyether group are added to further improve the dielectric breakdown resistance. [Effect] A molded product having a high dielectric breakdown voltage and stretched in at least one direction provides a polypropylene having a high dielectric breakdown voltage and an excellent balance of electrical properties and physical properties, which is extremely industrially valuable. There is. |