Granted Patent
Utility
US 5,990,352 · App. 08/796,893
Phosphazenium salt and preparation process thereof, and process for producing poly(alkylene oxide)
Inventors:
Tadahito Nobori, Masahiro Kouno, Toshiaki Suzuki, Kazumi Mizutani, Shinji Kiyono, Yoshiho Sonobe, Usaji Takaki
Patented Case
View Patent ↗
Granted: Nov 23, 1999
Filed: Feb 5, 1997
Inventors
Tadahito Nobori
Masahiro Kouno
Toshiaki Suzuki
Kazumi Mizutani
Shinji Kiyono
Yoshiho Sonobe
Usaji Takaki
Assignee (at issue)
MITSUI CHEMICALS, INC.
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.