Granted Patent
Utility
US 4,972,000 · App. 07/314,929
Hollow polymer particles, process for production thereof, and use thereof as pigment
Inventors:
Nobuo Kawashima, Fujio Sakurai, Hiroshi Tadenuma
Patented Case
View Patent ↗
Granted: Nov 20, 1990
Filed: Feb 24, 1989
Inventors
Nobuo Kawashima
Fujio Sakurai
Hiroshi Tadenuma
Assignee (at issue)
Japan Synthetic Rubber Corporation
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.