Nippon Zeon Company, Ltd.

Zeon Corporation

Fumio Takano

Eitaro Nakamura

Masahiro Yamakawa

Katsuya Nakamura

Akira Nakayama

Yasuhiro Wakizaka

Kouichirou Maeda

Takahiro Takasaki

Kenji Akimoto

The present invention is directed to an electrode for a nonaqueous electrolyte secondary battery and a nonaqueous electrolyte secondary battery using the same. The nonaqueous electrolyte secondary battery electrode includes an electrode material mixture and a current collector. The electrode material mixture includes an active material and a polymer. The thickness change rate of the electrode material mixture is &#x2212;3 to 10% when immersing in an electrolyte at 60&#xb0; C. for 72 hours.

Electrode for nonaqueous electrolyte secondary battery showing small variability in battery properties and nonaqueous electrolyte secondary battery using the same

Binder composition for lithium ion secondary battery electrodes and use thereof

A binder for coating materials containing dispersed inorganic powder comprises a polyurethane resin containing (a) 2.2 to 7.0 terminal epoxy groups in one molecule in average and (b) 0.1 to 5.0% by weight as SO.sub.3 -- of a sulfonic acid salt group, 0.05 to 3.0% by weight as COO-- of a carboxylic acid salt group, or 0.02 to 1.0% by weight as N.sup.+ of a quaternary ammonium salt group in the molecule, and having a number-average molecular weight of 2,000 to 10,000. A coating material containing dispersed inorganic powder and a magnetic recording medium both use this binder. In a recording medium comprising a magnetic layer placed on a non-magnetic substrate, the magnetic layer comprises polyurethane resin (A) as a binder, vinyl chloride polymer (B) containing 0.1 to 20% by weight of epoxy group and having an average degree of polymerization of 100 to 500, as another binder, (C) an alicylic acid anhydride as a crosslinking agent, and (E) a tertiary amine as a catalyst, and at least one of the binders is crosslinked between the epoxy groups therein by the reaction in which components (C) and (E) take part. The coating material containing fine inorganic powder dispersed with stability and having a low viscosity can be obtained by using, as the binder, the polyurethane resin having terminal epoxy groups and one of a sulfonic acid salt group, a carboxylic acid salt group, and a quaternary ammonium salt group. The magnetic recording material prepared by using magnetic powder as the inorganic powder and crosslinking the binder is excellent in dispersion of the magnetic powder and smoothness of the surface. Therefore, the magnetic recording medium is excellent in magnetic properties, durability, and running properties.

Magnetic recording medium having a specified binder system

A magnetic recording medium comprises a non-magnetic support on which is coated a magnetic layer. The magnetic layer contains a ferromagnetic powder dispersed in a binder. The binder comprises a styrene copolymer or an acrylic copolymer, respectively containing both of (i) an epoxy group and (ii) at least one hydrophillic group, such as a strong salt group or a tertiary ammonium salt group. The magnetic recording medium exhibits excellent recording density and S/N ratio, causes no environmental pollution, because of the absence of generation of hydrochloric acid on incineration of the magnetic recording medium for disposal after use. The magnetic recording medium is favorably utilized for magnetic tapes, magnetic sheets, magnetic discs and like products.

Magnetic recording medium comprising a styrene copolymer or an acrylic

Disclosed is a magnetic recording medium having a magnetic layer comprising a vinyl chloride copolymer as a binder and a magnetic powder and formed on a non-magnetic support. The vinyl chloride copolymer contains a hydroxyl group and a quaternary ammonium salt, wherein the hydroxyl group is derived from a monoallyl or monomethallyl ether of a polyhydroxyl compound, or a monoallyl or monomethallyl thioether of a polyhydroxyl compound. The vinyl chloride copolymer may further contain a hydrophilic group derived from at least one monomer which is selected from carboxylic acids, sulfur-containing acids, phosphorus-containing acids and salts thereof.

Magnetic recording medium

A magnetic coating comprising magnetic powder, a binder and an organic solvent, characterized in that at least one component of the binder is a vinyl chloride copolymer having hydroxyl group, and carboxylic acid groups or sulfur- or phosphorus-containing strong acid radicals, and the comonomer supplying the hydroxyl groups is a monoallyl ether of polyhydroxy compound, and a magnetic recording medium made by coating a substrate with the magnetic coating.

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Kawasaki, Japan

Fumio Takano