The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 19, 1995
Filed:
Jun. 08, 1993
Takeo Inoue, Osaka, JP;
Shigeru Kimura, Osaka, JP;
Tutomu Iwatani, Osaka, JP;
Takayuki Yamada, Osaka, JP;
Yukio Ishii, Osaka, JP;
Ryuichi Sugimoto, Osaka, JP;
Mitsui Toatsu Chemicals, Inc., Tokyo, JP;
Abstract
The invention provides a polymeric insulating material having a high dielectric breakdown voltage. The material comprises polypropylene which has been obtained in a yield of at least 300,000 g/g-Ti based on titanium in a catalyst upon polymerization, contains ash in an amount not greater than 40 ppm by weight when analyzed by completely burning the polypropylene in air, said ash containing titanium in an amount not greater than 1 ppm by weight based on the weight of the polypropylene, and also contains chlorine in an amount not greater than 2 ppm by weight and boiling n-heptane soluble matter in an amount not smaller than 1 wt. % but not greater than 10 wt. %. According to the invention, it is possible to further improve the dielectric breakdown voltage by adding to the polypropylene an inorganic oxide or hydroxide free of particles of 10 .mu.m and greater in diameter and having an average particle size not greater than 1 .mu.m, an organopolysilane, a maleic-anhydride-grafted polypropylene, or a silane compound containing at least one organic polyether group.