Granted Patent
Utility
US 5,282,997 · App. 07/893,633
Process and composition for deinking dry toner electrostatic printed wastepaper
Inventors:
Sandra K. Richmann, Mary Beth Letscher
Patented Case
View Patent ↗
Granted: Feb 1, 1994
Filed: Jun 5, 1992
Inventors
Sandra K. Richmann
Mary Beth Letscher
Assignee (at issue)
Betz PaperChem 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.