| abstract |
A binder composition for the positive electrode of an electric storage device. The composition contains polymer alloy particles composed of: a polymer (A) having a recurring unit derived from vinylidene fluoride, ethylene tetrafluoride, propylene hexafluoride, or mixtures thereof; a polymer (B) having a recurring unit derived from an unsaturated carboxylic acid ester; and water. The average diameter of the polymer alloy particles is 50 to 400 nm. The polymer alloy particles are synthesized by absorbing a monomer (b) to the polymer (A) and polymerizing the monomer (b) to synthesize the polymer (B). The monomer (b) is an unsaturated carboxylic acid ester, or a mixture of an unsaturated carboxylic acid ester and one or more of the following monomers: an α,β-unsaturated nitrile compound, an unsaturated carboxylic acid, a conjugated diene compound, styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, chlorostyrene, divinylbenzene, a carboxylic vinyl ester, and an acid anhydride of an ethylenically unsaturated dicarboxylic acid. |