Patent ID: 6667133
Filing Date: 2003-12-23
Classification: H01M

Abstract:
A swelling-in-water type gelating agent of a cross-linked polymer (A) comprising (meth)acrylic acid and/or its alkali metal salt as a main constituent monomer unit and obtained by an aqueous solution polymerization or a reversed phase suspension polymerization, wherein the gelating agent is for an alkaline cell and satisfies the following required conditions (1) to (4):required condition (1); that the gelating agent contains 50% by weight or more of a particle whose swollen particle size becomes 300 to 4,000 &mgr;m when the gelating agent is swollen in an aqueous potassium hydroxide solution of 40% by weight concentration; required condition (2); that the aqueous potassium hydroxide solution of 40% by weight concentration containing 3% by weight of the gelating agent has 0 to 20 mm stringiness; required condition (3); that the aqueous potassium hydroxide solution of 40% by weight concentration containing 3% by weight of the gelating agent has viscosity of 50 to 1,000 Pa.s at 40Â° C. after one day and sixty days; and required condition (4); that the gelating agent contains 0 to 15 ppm of a metal with a lower ionization tendency than zinc.