Abstract: The present invention provides a binder for a secondary battery having excellent binding force. A binder for a secondary battery comprising a polymer compound, wherein the polymer compound contains an acrylic repeating unit, and a 3% by mass aqueous solution of the polymer compound has a yellowness index of 14 or less.

Abstract: Disclosed is an additive for a nonaqueous electrolyte solution, containing a first compound represented by Formula (1) and a second compound which is a carbonate compound, a cyclic sulfone compound, and/or a cyclic disulfonic acid ester compound. [In Formula (1), Q represents an alkenylene group having 4 to 8 carbon atoms, which forms a cyclic group together with a sulfur atom of a sulfonyl group, X represents a sulfonyl group, a carbonyl group, or a phosphoryl group, R1 represents an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, an aryl group, an alkoxy group having 1 to 4 carbon atoms, an alkenyloxy group having 2 to 6 carbon atoms, an alkynyloxy group having 2 to 6 carbon atoms, or an aryloxy group, and n represents 1 or 2.

Abstract: The present invention provides a binder for a secondary battery having excellent binding force. A binder for a secondary battery comprising a polymer compound, wherein the polymer compound contains an acrylic repeating unit, and a 3% by mass aqueous solution of the polymer compound has a yellowness index of 14 or less.

Abstract: The present invention provides a method for producing a polymer compound for use as a binder for a secondary battery that exhibits reduced foaming when kneaded with an active material. A method for producing a polymer compound for use as a binder for a secondary battery, the polymer compound containing a repeating unit represented by formula (1) and a repeating unit represented by formula (2): [Formula 1] wherein each R1 is independently a hydrogen atom or a methyl group, and each R2 is independently an NH2 group, an OH group, an ONa group, or an OLi group, the method comprising the steps of copolymerizing monomers for forming the polymer compound in the presence of an azo polymerization catalyst; and saponifying the resulting copolymer.

Abstract: The present invention provides a binder for a secondary battery having excellent binding force. A binder for a secondary battery comprising a polymer compound, wherein the polymer compound contains an acrylic repeating unit, and a 3% by mass aqueous solution of the polymer compound has a Hazen color of 10 or more and 400 or less.

Abstract: The present invention provides a binder for a secondary battery that can reduce the initial resistance value of the secondary battery. A binder for a secondary battery comprising a polymer compound, wherein the polymer compound contains repeating units represented by formulae (1), (2), and (3): in formula (1), R1 is a hydrogen atom or a methyl group, and M is a hydrogen atom or an alkali metal atom; and in formula (3), R2 is a hydrogen atom or a methyl group; and when a total ratio of repeating units constituting the polymer compound is taken as 100 mol %, a total ratio of the repeating unit represented by formula (3) is less than 2 mol %.

Abstract: The present invention provides a binder for a secondary battery having excellent binding force. A binder for a secondary battery comprising a polymer compound, wherein the polymer compound contains repeating units represented by formulae (1), (2), and (3): in formula (1). R1 is a hydrogen atom or a methyl group, and M is a hydrogen atom or an alkali metal atom; and in formula (3), R2 is a hydrogen atom or a methyl group; and when a total ratio of repeating units constituting the polymer compound is taken as 100 mol %, a total ratio of the repeating unit represented by formula (3) is 2 mol % or more and 20 mol % or less.