Granted Patent
Utility
US 4,863,972 · App. 07/070,374
Porous cross-linked polyvinyl alcohol particles, process for producing the same, and separating agent composed of the same
Inventors:
Takaharu Itagaki, Hiroshi Kusano, Eiji Miyata, Takayuki TASHIRO
Patented Case
View Patent ↗
Granted: Sep 5, 1989
Filed: Jul 7, 1987
Inventors
Takaharu Itagaki
Hiroshi Kusano
Eiji Miyata
Takayuki TASHIRO
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.