Patent ID: 7579115

Claim:
A gelling agent for use in an alkaline battery, the gelling agent comprising a cross-linked polymer (A) formed with a (meth)acrylic acid (salt) as a principal constituent monomer unit, wherein the gelling agent allows an obtained gel (GA) to have a viscosity ratio (N1/N60), determined as follows, of 0.7 to 1.3, and includes components soluble in 37 wt % aqueous solution of potassium hydroxide that account for 30 wt % or less of the gelling agent: the viscosity ratio (N1/N60) of the gel (GA) is determined by preparing the gel (GA) by stirring 100 parts by weight of 37 wt % aqueous solution of potassium hydroxide, 2 parts by weight of the cross-linked polymer (A), and 200 parts by weight of zinc powder at 40° C. so as to be mixed uniformly, and measuring a viscosity (40° C., N1) of the gel (GA) after being left to stand at the same temperature for one day, and a viscosity (40° C., N60) of the gel (GA) after being left to stand at the same temperature for sixty days, according to JIS K7117-1: 1999, and wherein the cross-linked polymer (A) includes a cross-linking agent (b) unit that is decomposed by hydrolysis in an alkaline environment, and a cross-linking agent (c) unit that is not decomposed by hydrolysis in an alkaline environment.