HIGHLY WATER-ABSORBING RESIN

PROBLEM TO BE SOLVED: To obtain a resin excellent in water absorbency by polymerizing a polymerizable monomer in a form of aqueous solution dispersed as droplets in a hydrophobic organic solvent to prepare a particle with specific values or more of an absorption volume and a liquid-passing rate of physiological saline solution. SOLUTION: A particle with an absorption volume of physiological saline solution of 40 g/g or more and a liquid-passing rate of physiological saline solution of 300 ml/min or more is obtained. In particular, a particle with a product of the average particle diameter and the gel strength of 2.0 g/cm or more is preferred. A monomer aqueous solution to yield a water-absorbing resin is dispersed in a droplet manner in a hydrophobic organic solvent to conduct suspension polymerization. The resultant polymer particle is reacted with a multifunctional compound capable of reacting with the particle to form a crosslinking structure selectively on the surface of the polymer particle. As the polymer, generally unsaturated carboxylic acids, especially acrylic acid are used. The unsaturated carboxylic acids are preferably used with 60% of the acid groups neutralized by an alkali metal or ammonia.