The invention provides a method of improving the corrosion resistance of a metal substrate. The method comprises: (a) electrophoretically depositing on the substrate a curable electrodepositable coating composition to form a coating over at least a portion of the substrate, and (b) heating the substrate to a temperature and for a time sufficient to cure the coating on the substrate. The electrodepositable coating composition comprises a resinous phase dispersed in an aqueous medium, the resinous phase comprising: (1) an ungelled active hydrogen-containing, cationic salt group-containing resin electrodepositable on a cathode; (2) an at least partially blocked polyisocyanate curing agent; and (3) a pigment component comprising an inorganic, platelike pigment having an average equivalent spherical diameter of at least 0.2 microns. The electrodepositable coating composition demonstrates a pigment-to-binder ratio of at least 0.5. The coating composition contains less than 8 percent by weight of a grind vehicle.

A substrate with a Micro-Arc Oxidation (MAO) layer or an electrophoretic deposition (ED) layer on a first side of the substrate and an electrically insulating layer on a second side of the substrate.

A substrate with a Micro-Arc Oxidation (MAO) layer or an electrophoretic deposition (ED) layer on a first side of the substrate and an electrically insulating layer on a second side of the substrate.

A surface-treated steel sheet of the present invention includes: a base steel sheet; a surface treatment layer which is formed on at least one surface of the base steel sheet and includes an oxide layer and a metal layer; and a chemical conversion layer which is formed on a surface of the surface treatment layer. The surface treatment layer contains Zn in an adhered amount of 0.30 g/m.sup.2 to 2.00 g/m.sup.2 and Ni in an adhered amount of 0.03 g/m.sup.2 to 2.00 g/m.sup.2, which is equal to or lower than the adhered amount of Zn. In a case of performing a glow discharge spectrometry, at an interface between the oxide layer and the metal layer, an emission intensity of Fe atoms is 20% or less of the maximum emission intensity of the Fe atoms, and the emission intensity of Ni atoms is 20% or less of the maximum emission intensity of the Ni atoms. In addition, a first range in which the emission intensity of Zn atoms is 60% or higher of the maximum emission intensity of the Zn atoms and a second range in which the emission intensity of the Ni atoms is 60% or higher of the maximum emission intensity of the Ni atoms overlap.

A surface-treated steel sheet of the present invention includes: a base steel sheet; a surface treatment layer which is formed on at least one surface of the base steel sheet and includes an oxide layer and a metal layer; and a chemical conversion layer which is formed on a surface of the surface treatment layer. The surface treatment layer contains Zn in an adhered amount of 0.30 g/m.sup.2 to 2.00 g/m.sup.2 and Ni in an adhered amount of 0.03 g/m.sup.2 to 2.00 g/m.sup.2, which is equal to or lower than the adhered amount of Zn. In a case of performing a glow discharge spectrometry, at an interface between the oxide layer and the metal layer, an emission intensity of Fe atoms is 20% or less of the maximum emission intensity of the Fe atoms, and the emission intensity of Ni atoms is 20% or less of the maximum emission intensity of the Ni atoms. In addition, a first range in which the emission intensity of Zn atoms is 60% or higher of the maximum emission intensity of the Zn atoms and a second range in which the emission intensity of the Ni atoms is 60% or higher of the maximum emission intensity of the Ni atoms overlap.

Various embodiments provide a method of manufacturing an oxygen electrode. The method comprises: providing an electrically conductive substrate; depositing an electrocatalyst layer on the substrate; and intercalating alkali-metal ions into the catalyst layer. Some other embodiments provide an oxygen electrode manufactured in accordance with the method and a metal-air battery, a regenerative H.sub.2O.sub.2 fuel cell, a direct fuel cell, and an electrochemical cell comprising the oxygen electrode.

Various embodiments provide a method of manufacturing an oxygen electrode. The method comprises: providing an electrically conductive substrate; depositing an electrocatalyst layer on the substrate; and intercalating alkali-metal ions into the catalyst layer. Some other embodiments provide an oxygen electrode manufactured in accordance with the method and a metal-air battery, a regenerative H.sub.2O.sub.2 fuel cell, a direct fuel cell, and an electrochemical cell comprising the oxygen electrode.

It is an object of the present invention is to provide an electrodeposition coating composition and an electrodeposition coating method that enable the formation of a cured electrodeposition coating film that develops excellent throwing power and exhibits a good appearance. An electrodeposition coating composition of the present invention comprising: at least one compound (A) selected from the group consisting of a zinc compound (A-1) and a bismuth compound (A-2); an aminated resin (B); and a curing agent (C), wherein a milligram equivalent (MEQ (A)) of an acid per 100 g of a resin solid content in the composition is 27 or more; a coulombic efficiency of the composition is 30 mg/C or less; a film resistance of a 15-m-thick uncured electrodeposition coating film formed using the composition is 400 k.Math.cm.sup.2 or more; and a coating film viscosity of an electrodeposition coating film obtained from the composition is 3000 Pa.Math.s or less at 50 C.

It is an object of the present invention is to provide an electrodeposition coating composition and an electrodeposition coating method that enable the formation of a cured electrodeposition coating film that develops excellent throwing power and exhibits a good appearance. An electrodeposition coating composition of the present invention comprising: at least one compound (A) selected from the group consisting of a zinc compound (A-1) and a bismuth compound (A-2); an aminated resin (B); and a curing agent (C), wherein a milligram equivalent (MEQ (A)) of an acid per 100 g of a resin solid content in the composition is 27 or more; a coulombic efficiency of the composition is 30 mg/C or less; a film resistance of a 15-m-thick uncured electrodeposition coating film formed using the composition is 400 k.Math.cm.sup.2 or more; and a coating film viscosity of an electrodeposition coating film obtained from the composition is 3000 Pa.Math.s or less at 50 C.

The invention provides an electrodepositable coating composition comprising a resinous phase dispersed in an aqueous medium, said resinous phase comprising: (1) an ungelled active hydrogen-containing, cationic salt group-containing resin; (2) an at least partially blocked polyisocyanate curing agent; and (3) a pigment component, wherein the pigment component comprises an inorganic, platelike pigment present in the resinous phase, wherein the electrodepositable coating composition contains less than 8 percent by weight of a grind vehicle, based on the total weight of solids in the electrodepositable coating composition. The invention also provides methods of improving the corrosion resistance of a metal substrate and coated substrates.