Granted Patent
Utility
US 5,173,515 · App. 07/521,789
Fire retardant foams comprising expandable graphite, amine salts and phosphorous polyols
Inventors:
Wulf von Bonin, Dietmar Schapel
Patented Case
View Patent ↗
Granted: Dec 22, 1992
Filed: May 10, 1990
Inventors
Wulf von Bonin
Dietmar Schapel
Assignee (at issue)
Bayer Aktiengesellschaft
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.