PURPOSE: To increase the increasing rate of weight, which is the swelling magnification of a sheet such as a drying preventive sheet, a water holding member or the like, improve the water absorbing speed of the sheet and prevent the sheet from warping due to curling after water swelling, by coating water swelling coating, obtained by mixing water swelling urethane resin and high water absorbing resin, on a base fabric.

CONSTITUTION: Water selling coating, obtained by mixing water swelling urethane resin and high water absorbing resin, is applied on an extendable base fabric. The composition of the water swelling coating is preferably contain 0.1W50pts.wt. of high water absorbing resin per 100pts.wt. of water swelling urethane resin. The amount of application of the water swelling coating with respect to the extendable base fabric is 50gW2kg per 1m2 generally. Terminal isocyanate compound, having the main chain of alkylene oxide, is employed as the water swelling urethane resin. The saponified copolymer of vinyl acetate and acrylic ester, the crosslinked modified copolymer of isobutylene-maleic anhydride or the like is employed as the high water absorbing resin. Referring to the grain size of the high water absorbing resin, the finer the better, and it is preferably normally less than 50μm.