A gelling material is composed of water-absorbent resin 12 wrapped in a bag composed of two laminated water-soluble sheets 1.1, the water-absorbent resin being prepared so as to enable the bag to be disintegrated by an inner pressure generated when an expanded volume of the water-absorbent resin by absorbing...http://www.google.es/patents/US6399668?utm_source=gb-gplus-sharePatente US6399668 - Water absorbent resin
