| abstract |
An improved superabsorbent polymer having increased rate of water absorption is obtained by the addition, preferably prior to polymerization, of a carbonate blowing agent to a monomer solution of the monomers used to form the superabsorbent polymer. Preferred monomers include (meth)acrylic acids, preferably partially neutralized prior to polymerization and appropriate cross-linking agents. The carbonate cross-linking agents are any carbonate salt soluble or dispersible in the monomer solution, prior to polymerization. The multi-valent cationic salts of carbonate are preferred, especially the complex carbonates, for example, of magnesium. |