PRODUCTION OF HIGHLY WATER-ABSORPTIVE RESIN EXCELLENT IN SALT RESISTANCE

摘要

PURPOSE:To produce the title resin which can highly absorb an electerolyte solution and hold it stably, by crosslinking a resin obtained by suspension- polymerizing an acidic vinyl monomer with a basic vinyl monomer with a specified cross-linking agent. CONSTITUTION:An aqueous monomer solution containing 30-70 wt.% mixture comprising 20-80 mol % acidic vinyl monomer (e.g., dimethylaminoethyl methacrylate) is dispersed and suspended in a hydrophobic solvent (e.g., hexane) in the presence of a dispersant (e.g., sorbitan monostearate), The obtained suspension is copolymerized in the presence of a water-soluble radical polymerization initiator to obtain a resin. The water content of this resin is adjusted to 10-35 wt. % by concentration, and the resin is crosslinked with 0.01 - 5.0 wt. % crosslinking agent having at least two functional groups rective with the acidic or basic group in the copolymer (e.g., ethylene glcyol diglycidyl ether).