| 摘要 |
PURPOSE:To obtain resin sheet having a high water content retaining power with almost no volumetric expansion by a method wherein highly water absorbent resin particles are dispersed in the interior of a large number of pores of porous resin sheet. CONSTITUTION:As the porous resin, flexible polyurethane resin or the like is favorable. Though there is no special qualification as the water absorbent resin, polyacrylic resin is favorable and the favorable particle diameter is 5 - 200mum and the ratio of the mean pore diameter D of the porous resin to the mean particle diameter (d) of the water absorbent resin is favorably to be D/d>2 and especially favorably to be 5<D/d<100. The manufacture of sheet is done by blending the water absorbent resin powder with water for swelling and, after that, mixing with liquid polyurethane. At this time, let XA, XH and XU% denote the mixing percentages by weight of the water absorbent resin powder, of the water and of the liquid polyurethane resin, then XA+XH+XU=100 and preferably 2<=XA<=20, 2<=XH<=90 and 5<=XU<=70. The mixture is introduced onto a bottom paper at a foaming part so as to be formed in slab foam through foaming and hardening. After that, the foam is sliced in a desired thicknesses. When necessary, the sliced foam is aged for proceeding enough hardening. |
