Surface treating water-absorbent resins with a polyquaternary amine substantially increases both the rate of water absorption and the quantity of water absorbed and retained by the resin. In addition to improved water absorbing properties, the surface-treated resins maintain the necessary "dry feel"...http://www.google.es/patents/US4824901?utm_source=gb-gplus-sharePatente US4824901 - Surface treated absorbent polymers
