| abstract |
A gelling agent capable of turning an electrolyte solution for an alkaline battery into a gel, which is less likely to cause syneresis, is composed of particles of a carboxyl group-containing polymer, and a 0.1% by weight aqueous solution has a viscosity of at least 3,000 mPa·s at a pH of 7. The particles of a carboxyl group-containing polymer are normally obtainable by polymerizing a polymerizable material containing α,β-unsaturated carboxylic acids, for example, a polymerizable material containing α,β-unsaturated carboxylic acids and a compound having two or more ethylenically unsaturated groups as a cross-linking agent, in an inert solvent which dissolves the α,β-unsaturated carboxylic acids but does not dissolve particles of a carboxyl group-containing polymer. The above-mentioned viscosity is achieved by adjusting the balance among the concentration of the α,β-unsaturated carboxylic acids, the concentration of a cross-linking agent and a polymerization temperature during polymerization. |