The present invention provides a method of tin-plating a copper alloy for electric or electronic parts and automobile parts which has excellent insertion force, heat-resistant peeling, and solderability, and a tin-plating material of a copper alloy manufactured therefrom.

The present invention provides a method of tin-plating a copper alloy for electric or electronic parts and automobile parts which has excellent insertion force, heat-resistant peeling, and solderability, and a tin-plating material of a copper alloy manufactured therefrom.

There is provided a non-oriented electrical steel sheet that includes a base metal steel sheet and an insulating coating film that is formed on a surface of the base metal steel sheet, wherein the insulating coating film mainly contains metal phosphate, organic resin, and water-soluble organic compound, the water-soluble organic compound has an SP value that is within a range of 10.0 to 20.0 (cal/cm.sup.3).sup.1/2, the metal phosphate contains aluminum and zinc as metallic elements, and when measurement by an X-ray photoelectron spectroscopy is performed from a surface of the insulating coating film in a thickness direction of the non-oriented electrical steel sheet, a depth at which a strength of a 2p peak of zinc reaches a maximum is present closer to the surface side than a depth at which a strength of a 2p peak of aluminum reaches a maximum, and a maximum value of the strength of the 2p peak of zinc is 1 to 20 times a strength of the 2p peak of aluminum at the depth at which the strength of the 2p peak of zinc reaches a maximum.

An electrical steel sheet (1) includes a base material (2) of electrical steel, and an insulating film (3) formed on a surface of the base material (2), the insulating film (3) containing a polyvalent metal phosphate and Fe. A maximum value of a parameter Q expressed by “Q=C.sub.Fe—O/C.sub.P” is equal to or less than 1.3 times an average value of the parameter Q in a region from a first depth from a surface of the insulating film to a second depth, C.sub.Fe—O denoting a proportion (atom %) of Fe bonded to O relative to all elements, and C.sub.P denoting a proportion (atom %) of P relative to all elements. The first depth is 20 nm from the surface, and the second depth is a depth where the proportion of P is equal to a proportion of metal Fe.

The present invention relates to a method for zinc phosphating of metal surfaces using a colloidal aqueous solution as activation stage, a zinc phosphate layer having a layer weight of less than 2.0 g/m.sup.2 being deposited on surfaces of zinc in the method step following activation. The activation stage is based on a colloidal aqueous solution containing a dispersed particulate constituent, the particulate constituent containing, in addition to dispersed inorganic compounds of phosphates of polyvalent metal cations, a polymeric organic compound as a dispersing agent that is composed at least partially of styrene and/or an α-olefin having no more than 5 carbon atoms, the polymeric organic compound additionally comprising units of maleic acid, their anhydride and/or their imide and the polymeric organic compound additionally comprising polyoxyalkylene units.

The present invention relates to a method for zinc phosphating of metal surfaces using a colloidal aqueous solution as activation stage, a zinc phosphate layer having a layer weight of less than 2.0 g/m.sup.2 being deposited on surfaces of zinc in the method step following activation. The activation stage is based on a colloidal aqueous solution containing a dispersed particulate constituent, the particulate constituent containing, in addition to dispersed inorganic compounds of phosphates of polyvalent metal cations, a polymeric organic compound as a dispersing agent that is composed at least partially of styrene and/or an α-olefin having no more than 5 carbon atoms, the polymeric organic compound additionally comprising units of maleic acid, their anhydride and/or their imide and the polymeric organic compound additionally comprising polyoxyalkylene units.

An electrical steel sheet (1) includes a base material (2) of electrical steel, and an insulating film (3) formed on a surface of the base material (2). The insulating film (3) contains a phosphates of one or more selected from the group consisting of Al, Zn, Mg and Ca. The phosphate exhibits a specific peak having a top within a range of −26 ppm to −16 ppm in a solid .sup.31P-NMR spectrum, and a proportion of an integrated intensity of the specific peak relative to an integrated intensity of all peaks in the solid .sup.31P-NMR spectrum is 30% or more.

The invention relates to a process for coating metal surfaces with an aqueous composition in the form of a solution or in the form of a dispersion, the composition comprising at least one phosphate, at least 3 g/l of at least one titanium or/and zirconium compound and at least one complexing agent, and also to corresponding aqueous compositions. The coatings prepared thereby have very good bare corrosion protection in the NSS salt spray test and in the condensation-water/constant-climate test

The invention relates to a process for coating metal surfaces with an aqueous composition in the form of a solution or in the form of a dispersion, the composition comprising at least one phosphate, at least 3 g/l of at least one titanium or/and zirconium compound and at least one complexing agent, and also to corresponding aqueous compositions. The coatings prepared thereby have very good bare corrosion protection in the NSS salt spray test and in the condensation-water/constant-climate test

A treatment agent for chromium-free insulating coating formation suitable for forming an insulating coating on a surface of a grain-oriented electrical steel sheet. The treatment agent includes components (A), (B), (C), and (D). The component (B) is contained in an amount of 50 to 150 parts by mass on a SiO.sub.2 solid basis, and the component (C) is contained in an amount of 5.0 parts by mass or more on an elemental metal basis, the amounts being based on 100 parts by mass, on a solid basis, of the component (A). The component (D) is contained in an amount that a molar ratio of M.sup.2+ and M.sup.3+, each being a metal element in the treatment agent for chromium-free insulating coating formation, to a phosphorus element P satisfies a specified relationship, and the treatment agent for chromium-free insulating coating formation has a pH of less than 4.5.