Liquification of trans, trans-4,4'-diisocyanate dicyclohexylmethane by partially reacting the isocyanate groups with blocking agents

Granted: Oct 3, 1995 Filed: Jun 30, 1993

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.