Methods for synthesizing polyvinyl amine (PVA) type flocculating and coagulating agents, novel agents thus obtained, uses thereof and improved paper types thus obtained

Granted: Sep 28, 2004 Filed: Dec 31, 2001

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.