Granted Patent
Utility
US 4,940,779 · App. 07/328,720
Method for the preparation of a polycarbonate powder
Inventors:
Takashi Ashida, Koji Yamamoto
Patented Case
View Patent ↗
Granted: Jul 10, 1990
Filed: Mar 23, 1989
Inventors
Takashi Ashida
Koji Yamamoto
Assignee (at issue)
Idemitsu Petrochemical Co., Ltd.
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.