Granted Patent
Utility
US 5,212,247 · App. 07/533,757
Polypropylene resin compositions of high syndiotacticity and preparation process thereof
Inventors:
Tadashi Asanuma, Tetsunosuke Shiomura, Nobutaka Uchikawa, Tutomu Iwatani, Katsumi Takeuchi
Patented Case
View Patent ↗
Granted: May 18, 1993
Filed: Jun 6, 1990
Inventors
Tadashi Asanuma
Tetsunosuke Shiomura
Nobutaka Uchikawa
Tutomu Iwatani
Katsumi Takeuchi
Assignee (at issue)
Mitsui Toatsu Chemicals, Incorporated
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.