| abstract |
The invention relates to the following processes for the production of high water absorption resins: (A) suspending an aqueous solution of a partially neutralized alkali metal acrylate and an optionally partially neutralized acrylamido alkane sulfonate, in a hydrocarbon solvent comprising a surfactant having a hydrophilic-lipophilic balance (HLB) value of 3~6 or 8~12; (B) subjecting the mixture to reverse suspension polymerization in the presence of at least one water-soluble radical polymerization initiator; (C) if necessary, separating the moisture from the resulting polymer by azeotropic distillation so as to reduce the water content to between about 15% and 55% by weight; (D) adding a crosslinking agent having two or more groups such as epoxy groups, if necessary, as a form of solution for subjecting the surface of the polymer to a crosslinking reaction; and, optionally, (E) performing coagulation using a coagulant in the presence of an inert solvent, and then drying the obtained coagulate so as to produce the water-absorbable resin. |