| 摘要 |
PROBLEM TO BE SOLVED: To obtain a water absorbent having a specified particle diameter, being excellent in absorption performance and an absorption rate and scarcely forms fine particles when external force such as a mechanical shock, frictional force or vibration during transportation is exerted thereon by pressure-molding a water-absorbing resin powder containing a specified amount of fine particles having a specified particle diameter under specified applied pressure in the presence of water. SOLUTION: This absorbent has a mean particle diameter of 200-1,000μm and is obtained by pressure-molding a water-absorbing resin powder containing at least 30mass% fine particles having a particle diameter of 150μm or below in the presence of water under a facial pressure of at least 50kg/cm<2> or a linear pressure of at least 25kg/cm or above and optionally subjecting the product to drying or drying and grinding. The water-absorbing resin is desirably one having an absorption amount of 40g/g or above at atmospheric pressure for physiological saline solution and an absorption amount of 20g/g or above under a pressure of 20g/cm<2> for the same solution. Preferably, the water-absorbing resin powder is premixed with at most 5mass% inorganic powder selected among silicon dioxide, titanium oxide and aluminum oxide, and water is then added to the mixture. |
