Granted Patent
Utility
US 4,808,683 · App. 07/062,755
Vinylamine copolymer, flocculating agent using the same, and process for preparing the same
Inventors:
Takaharu Itagaki, Mitsuaki Shiraga, Shigeru Sawayama, Kohichi Satoh
Patented Case
View Patent ↗
Granted: Feb 28, 1989
Filed: Jun 16, 1987
Inventors
Takaharu Itagaki
Mitsuaki Shiraga
Shigeru Sawayama
Kohichi Satoh
Assignee (at issue)
Mitsubishi Chemical Industries, 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.