The present invention relates to: a rust-proofing treatment method comprising the step of treating an object that comprises a metal or an alloy and is heated to a temperature higher than 180° C. or an object that has, formed on the surface thereof, a film or layer comprising a metal or an alloy and is heated to a temperature higher than 180° C. with an aqueous solution containing an inorganic acid or an inorganic salt, or comprising the step of treating an object comprising a metal or an alloy or an object having, formed on the surface thereof, a film or layer comprising a metal or an alloy with an aqueous solution containing at least one component selected from silicic acid, a silicic acid salt, phosphoric acid, a phosphoric acid salt, a monohydrogen phosphate salt, a dihydrogen phosphate salt and a zirconium salt; and an article characterized by being rust-proofing-treated by the rust-proofing treatment method.

A method for providing composite phosphate conversion crystal coating, including the steps of: mixing powdered materials with metal oxide particles, thereby providing a composite metal oxide powder including particles of at least one additional powdered material, the at least one additional powdered material providing additional functionality to the phosphate conversion crystal coating; pretreating a substrate by depositing particles of the composite metal oxide powder on the substrate; treating the substrate with a phosphate coating solution, resulting in the composite phosphate conversion crystal coating forming on the substrate which contains fixed particles of the at least one additional powdered material.

A method for providing composite phosphate conversion crystal coating, including the steps of: mixing powdered materials with metal oxide particles, thereby providing a composite metal oxide powder including particles of at least one additional powdered material, the at least one additional powdered material providing additional functionality to the phosphate conversion crystal coating; pretreating a substrate by depositing particles of the composite metal oxide powder on the substrate; treating the substrate with a phosphate coating solution, resulting in the composite phosphate conversion crystal coating forming on the substrate which contains fixed particles of the at least one additional powdered material.

Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of a primary coating to the steel sheet is provided. The grain-oriented electrical steel sheet is provided with a base steel sheet having a chemical composition containing C: 0.005% or less, Si: 2.5 to 4.5%, Mn: 0.050 to 1.000%, a total of S and Se: 0.005% or less, sol. Al: 0.005% or less, and N: 0.005% or less and having a balance of Fe and impurities and a primary coating having Mg.sub.2 SiO.sub.4 as a main constituent formed on a surface of the base steel sheet. A peak position of Al emission intensity obtained when conducting elemental analysis by glow discharge spectrometry from a surface of the primary coating in a thickness direction is present in a range of 2.0 to 12.0 μm from a surface of the primary coating to the thickness direction. A sum of perimeters of the Al oxides at the peak position of Al emission intensity is 0.20 to 1.00 μm/μm.sup.2, and a number density of Al oxides is 0.02 to 0.20/μm.sup.2.

Provided herein is a method for specifically adjusting the electrical conductivity of a conversion coating, wherein a metallic surface or a conversion-coated metallic surface is treated with an aqueous composition which comprises at least one kind of metal ions selected from the group consisting of the ions of molybdenum, copper, silver, gold, palladium, tin, and antimony and/or at least one electrically conductive polymer selected from the group consisting of the polymer classes of the polyamines, polyanilines, polyimines, polythiophenes, and polypryrols.

Provided herein is a method for specifically adjusting the electrical conductivity of a conversion coating, wherein a metallic surface or a conversion-coated metallic surface is treated with an aqueous composition which comprises at least one kind of metal ions selected from the group consisting of the ions of molybdenum, copper, silver, gold, palladium, tin, and antimony and/or at least one electrically conductive polymer selected from the group consisting of the polymer classes of the polyamines, polyanilines, polyimines, polythiophenes, and polypryrols.

This application describes covers for electronic devices, electronic devices, and methods for making the covers. In one example, described herein is a cover for an electronic device comprising: a substrate comprising a metal; a passivation layer or a micro-arc oxidation layer deposited on at least one surface of the substrate; a primer coating layer on the passivation layer or the micro-arc oxidation layer; an optional base coating layer on the primer coating layer; a top coating layer on the optional base coating layer or on the primer coating layer; and a hydrophobic coating layer.

Provided is a solution composition for steel sheet surface treatment, comprising 30 wt % to 60 wt % of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B); 0.2 wt % to 0.4 wt % of a rust-inhibiting and corrosion-resisting agent; 0.1 wt % to 0.3 wt % of a molybdenum-based compound; 5 wt % to 10 wt % of a water-soluble cationic urethane resin; 0.5 wt % to 2.0 wt % of a silane coupling agent; and 27.3 wt % to 64.2 wt % of water, a zinc-based plated steel sheet surface-treated with the same, and a manufacturing method therefor, the zinc-based plated steel sheet surface-treated with the solution composition for steel sheet surface treatment containing trivalent chromium may have an excellent effect on corrosion resistance, blackening resistance, fingerprint resistance, oil resistance, and alkali resistance.

Provided is a solution composition for steel sheet surface treatment, comprising 30 wt % to 60 wt % of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B); 0.2 wt % to 0.4 wt % of a rust-inhibiting and corrosion-resisting agent; 0.1 wt % to 0.3 wt % of a molybdenum-based compound; 5 wt % to 10 wt % of a water-soluble cationic urethane resin; 0.5 wt % to 2.0 wt % of a silane coupling agent; and 27.3 wt % to 64.2 wt % of water, a zinc-based plated steel sheet surface-treated with the same, and a manufacturing method therefor, the zinc-based plated steel sheet surface-treated with the solution composition for steel sheet surface treatment containing trivalent chromium may have an excellent effect on corrosion resistance, blackening resistance, fingerprint resistance, oil resistance, and alkali resistance.

Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of a primary coating to the steel sheet is provided. The grain-oriented electrical steel sheet is provided with a base steel sheet having a chemical composition containing C: 0.005% or less, Si: 2.5 to 4.5%, Mn: 0.050 to 1.000%, a total of S and Se: 0.005% or less, sol. Al: 0.005% or less, and N: 0.005% or less and having a balance of Fe and impurities and a primary coating having Mg.sub.2 SiO.sub.4 as a main constituent formed on a surface of the base steel sheet. A peak position of Al emission intensity obtained when conducting elemental analysis by glow discharge spectrometry from a surface of the primary coating in a thickness direction is present in a range of 2.0 to 12.0 .Math.m from a surface of the primary coating to the thickness direction. A sum of perimeters of the Al oxides at the peak position of Al emission intensity is 0.20 to 1.00 .Math.m/.Math.m.sup.2, and a number density of Al oxides is 0.02 to 0.20 /.Math.m.sup.2.