Polyisocyanate based upon 4,4'-and 2,4'-diphenyl-methane dllsocyanates and use thereof in a rim process

Granted: Dec 17, 1996 Filed: Jun 6, 1995

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.