A surface treated copper foil 1 includes a copper foil 2, and a first surface treatment layer 3 formed on one surface of the copper foil 2. The first surface treatment layer 3 of the surface treated copper foil 1 has a Ni concentration of 0.1 to 15.0 atm % based on the total amount of elements of C, N, O, Zn, Cr, Ni, Co, Si, and Cu, in an XPS depth profile obtained by performing sputtering at a sputtering rate of 2.5 nm/min (in terms of SiO.sub.2) for 1 minute. A copper clad laminate 10 includes the surface treated copper foil 1 and an insulating substrate 11 adhered to the first surface treatment layer 3 of the surface treated copper foil 1.

A surface treated copper foil 1 includes a copper foil 2, and a first surface treatment layer 3 formed on one surface of the copper foil 2. The first surface treatment layer 3 of the surface treated copper foil 1 has a Ni deposited amount of 20 to 200 μg/dm.sup.2 and a Zn deposited amount of 20 to 1,000 μg/dm.sup.2. A copper clad laminate 10 includes the surface treated copper foil 1 and an insulating substrate 11 adhered to the first surface treatment layer 3 of the surface treated copper foil 1.

A surface treated copper foil 1 includes a copper foil 2, and a first surface treatment layer 3 formed on one surface of the copper foil 2. The first surface treatment layer 3 of the surface treated copper foil 1 has a root mean square gradient of roughness curve elements RΔq according to JIS B0601:2013 of 5 to 28°. A copper clad laminate 10 includes the surface treated copper foil 1 and an insulating substrate 11 adhered to the first surface treatment layer 3 of the surface treated copper foil 1.

The present invention relates to a method for increasing the corrosion resistance of a chrome-plated substrate wherein at least one part of a chrome-plated surface of a chrome-plated substrate is dipped into an electrolyte comprising trivalent chromium ions, at least one conducting salt and at least one reducing agent, and afterwards, a trivalent chromium oxide film is formed on the at least one part of the chrome-plated surface by applying a pulse reverse current between the chrome-plated surface and a counter electrode electrically connected with the chrome-plated surface through the electrolyte. Furthermore, the present invention relates to a chrome-plated substrate obtainable by this method.

The present invention relates to a method for increasing the corrosion resistance of a chrome-plated substrate wherein at least one part of a chrome-plated surface of a chrome-plated substrate is dipped into an electrolyte comprising trivalent chromium ions, at least one conducting salt and at least one reducing agent, and afterwards, a trivalent chromium oxide film is formed on the at least one part of the chrome-plated surface by applying a pulse reverse current between the chrome-plated surface and a counter electrode electrically connected with the chrome-plated surface through the electrolyte. Furthermore, the present invention relates to a chrome-plated substrate obtainable by this method.

A surface treated copper foil 1 includes a copper foil 2, and a first surface treatment layer 3 formed on one surface of the copper foil 2. The first surface treatment layer 3 of the surface treated copper foil 1 has a Ni deposited amount of 20 to 200 μg/dm.sup.2 and a Zn deposited amount of 20 to 1,000 μg/dm.sup.2. A copper clad laminate 10 includes the surface treated copper foil 1 and an insulating substrate 11 adhered to the first surface treatment layer 3 of the surface treated copper foil 1.

A surface treated copper foil 1 includes a copper foil 2, and a first surface treatment layer 3 formed on one surface of the copper foil 2. The first surface treatment layer 3 of the surface treated copper foil 1 has L* of a CIE L*a*b* color space of 44.0 to 84.0. A copper clad laminate 10 includes the surface treated copper foil 1 and an insulating substrate 11 adhered to a surface of the surface treated copper foil 1 opposite to the first surface treatment layer 3.

This invention is directed to a process of coating metal in a trivalent chromium conversion-electrolyte coating wherein the metal anode or cathode is subjected to a current density ranging up to about 3.0 amperes per square foot for a period ranging up to 60 minutes.

A steel sheet for can making and methods for manufacturing the same. The steel sheet includes, in order from a steel sheet side, an iron-nickel diffusion layer, a metallic chromium layer, and a chromium oxide layer. The iron-nickel diffusion layer has a nickel coating weight of 50 mg/m.sup.2 to 500 mg/m.sup.2 per surface of the steel sheet and a thickness of 0.060 μm to 0.500 μm per surface of the steel sheet. The metallic chromium layer includes a flat-like metallic chromium sublayer and a granular metallic chromium sublayer placed on a surface of the flat-like metallic chromium sublayer. The total chromium coating weight of both sublayers per surface of the steel sheet is 60 mg/m.sup.2 to 200 mg/m.sup.2. The chromium oxide layer has a chromium coating weight 3 mg/m.sup.2 to 10 mg/m.sup.2 per surface of the steel sheet in terms of metallic chromium.

A steel sheet for can making and methods for manufacturing the same. The steel sheet includes, in order from a steel sheet side, an iron-nickel diffusion layer, a metallic chromium layer, and a chromium oxide layer. The iron-nickel diffusion layer has a nickel coating weight of 50 mg/m.sup.2 to 500 mg/m.sup.2 per surface of the steel sheet and a thickness of 0.060 μm to 0.500 μm per surface of the steel sheet. The metallic chromium layer includes a flat-like metallic chromium sublayer and a granular metallic chromium sublayer placed on a surface of the flat-like metallic chromium sublayer. The total chromium coating weight of both sublayers per surface of the steel sheet is 60 mg/m.sup.2 to 200 mg/m.sup.2. The chromium oxide layer has a chromium coating weight 3 mg/m.sup.2 to 10 mg/m.sup.2 per surface of the steel sheet in terms of metallic chromium.