The invention provides a stable polymeric additive useful for improving the wet strength of a cellulosic substrate. The additive is a water-soluble cationic thermosetting polymer incorporating a plurality of extralinear glycidyl quaternary ammonium groups. The invention also comprises a method of making...http://www.google.es/patents/US4298639?utm_source=gb-gplus-sharePatente US4298639 - Wet strength polymers
