Dai-ichi Kogyo Seiyaku Co., Ltd.

Takeshi Miyamura

Katsuo Takahashi

Shuichi Ito

Takeshi Doi

Toshio Kagimasa

Masahiro Kouchi

Kei Oikawa

Masaharu Hirose

Katsuyoshi Kobayashi

A binder for an electrode of a lithium secondary battery contains a water dispersion of a polyurethane. The polyurethane has been formed of (A) a polyisocyanate, (B) a compound having two or more active hydrogen groups, (C) a compound having one or more active hydrogen groups and a hydrophilic group, and (D) a chain extending agent. The (B) compound having two or more active hydrogen groups contains an olefinic polyol and/or a carbonate diol having a carbon number between carbonate bond chains of less than 6. The binder has high adhesiveness to a collector, does not cause release in press molding, has high flexibility, and is excellent in bindability and resistance to an electrolytic solution.

Binder for electrode in lithium secondary cell, electrode manufactured using said binder, and lithium secondary cell in which said electrode is used

A binder for an electrode of a lithium secondary battery contains a polyurethane aqueous dispersion. The polyurethane aqueous dispersion contains a hydrophilic group-containing polyurethane obtained by using at least (A) an organic polyisocyanate and (B) a compound having one or more active hydrogen groups. (A) the organic polyisocyanate has a content of 50 mass % or more and 80 mass % or less based on the hydrophilic group-containing polyurethane. (B) the compound having one or more active hydrogen groups contains (B1) a compound having one or more active hydrogen groups and (B2) a compound having one or more active hydrogen groups and one or more ionic hydrophilic groups.

Binder for electrode of lithium secondary cell

To provide a binder that has high adhesiveness to a collector, does not cause release in press molding, has high flexibility, and is excellent in binding capability and resistance to an electrolytic solution, and to provide a lithium secondary battery that is excellent in charge and discharge characteristics using an electrode produced with the binder. The binder for an electrode used contains a hydrophilic group-containing polyurethane as a water dispersion that contains (A) a polyisocyanate, (B) a compound that has two or more active hydrogen groups, (C) a compound that has one or more active hydrogen groups and one or more hydrophilic groups, and (D) a chain extending agent, or contains an aqueous resin composition containing a polymer of an unsaturated polymerizable monomer that is emulsified with the hydrophilic group-containing polyurethane.

Binder for electrodes of lithium secondary batteries, and lithium secondary battery which uses electrode produced using binder for electrodes of lithium secondary batteries

For use as a wet strength agent, a water-soluble blocked urethane prepolymer having a hydrophilic group and a blocked isocyanate group is combined with a cationic charge-adjusting agent. The adsorption and retention of the water-soluble blocked urethane prepolymer to cellulosic fiber are promoted by virtue of the cationic charge adjusting agent when the wet strength agent is added to a paper-making stock.

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Kyoto, Japan

Takeshi Miyamura