Disclosed herein are a surface-treated copper foil for a negative electrode current collector for secondary batteries, a method for producing the same, and a negative electrode for secondary batteries including the same. The surface-treated copper foil includes needle-shaped copper particles formed on at least one surface thereof, wherein the copper particles have an average major-axis length of about 0.6 μm to about 2.0 μm and are separated from one another by a distance of about 1 μm to about 5 μm.

In certain aspects, a coated steel substrate comprises a single or multiple-layer electroplated aluminum coating over a steel substrate. The multiple-layer electroplated aluminum coating comprises one or more porous layers and one or more compact layers. The one or more porous layers comprise a material selected from a group consisting of aluminum and aluminum alloys. The one or more compact layers comprise a material selected from a group consisting of aluminum and aluminum alloys. In certain aspects, a method of depositing a multiple-layer aluminum coating over a steel substrate includes electroplating one or more porous aluminum layers over the steel substrate. The one or more porous aluminum layers comprise a material selected from a group consisting of aluminum and aluminum alloys. One or more compact aluminum layers are electroplated over the steel substrate. The one or more compact aluminum layers comprise a material selected from a group consisting of aluminum and aluminum alloys.

The present invention addresses the problem of providing a flame treatment device which is capable of performing a flame treatment on a metal-based base material without requiring a preheat treatment. For the purpose of solving the above-described problem, a flame treatment device according to the present invention comprises: a first temperature measurement unit which measures the temperature of a metal-based base material before a flame treatment; a control unit which determines the combustion energy of flame on the basis of the temperature before a flame treatment, said temperature having been measured by the first temperature measurement unit, so that the surface temperature of the metal-based base material during the flame treatment is 56° C. or higher; and a flame treatment unit which performs a flame treatment on the metal-based base material on the basis of the combustion energy, which has been determined by the control unit.

An acidic treatment liquid processing apparatus includes: a tank having an interior space; a diaphragm permeable to a metal cation and separating the interior space of the tank into a first chamber and a second chamber; a first electrode disposed in the first chamber; a second electrode disposed in the second chamber; a power supply configured to apply a voltage while using the first electrode as an anode and the second electrode as a cathode; a first liquid passing part configured to pass an acidic treatment liquid containing a dichromate ion and a metal cation into the first chamber; and a second liquid passing part configured to pass an acid aqueous solution into the second chamber.

In certain aspects, a coated steel substrate comprises a single or multiple-layer electroplated aluminum coating over a steel substrate. The multiple-layer electroplated aluminum coating comprises one or more porous layers and one or more compact layers. The one or more porous layers comprise a material selected from a group consisting of aluminum and aluminum alloys. The one or more compact layers comprise a material selected from a group consisting of aluminum and aluminum alloys. In certain aspects, a method of depositing a multiple-layer aluminum coating over a steel substrate includes electroplating one or more porous aluminum layers over the steel substrate. The one or more porous aluminum layers comprise a material selected from a group consisting of aluminum and aluminum alloys. One or more compact aluminum layers are electroplated over the steel substrate. The one or more compact aluminum layers comprise a material selected from a group consisting of aluminum and aluminum alloys.

A steel sheet for cans which exhibits excellent weldability; and a production method therefore include the surface of a steel sheet in order from the steel sheet side, a chromium metal layer and a hydrous chromium oxide layer. The deposited amount of the chromium metal layer is 50-200 mg/m.sup.2. The deposited amount of the hydrous chromium oxide layer in terms of chromium is 3-30 mg/m.sup.2. The chromium metal layer includes: a base part having a thickness of 7.0 nm or higher; and granular protrusions which are on the base part, have a maximum grain size of 200 nm or lower, and have a number density per unit area of at least 30 per m.sup.2.

The present invention addresses the problem of providing a flame treatment device which is capable of performing a flame treatment on a metal-based base material without requiring a preheat treatment. For the purpose of solving the above-described problem, a flame treatment device according to the present invention comprises: a first temperature measurement unit which measures the temperature of a metal-based base material before a flame treatment; a control unit which determines the combustion energy of flame on the basis of the temperature before a flame treatment, said temperature having been measured by the first temperature measurement unit, so that the surface temperature of the metal-based base material during the flame treatment is 56 C. or higher; and a flame treatment unit which performs a flame treatment on the metal-based base material on the basis of the combustion energy, which has been determined by the control unit.

Provided is a copper foil. The copper foil includes a copper layer and a protective layer disposed on the copper layer, wherein a surface of the protective layer has a maximum height roughness (R.sub.max) of 0.6 m to 3.5 m, a peak density (PD) of 5 to 110, and an oxygen atomic amount of 22 at % (atomic %) to 67 at %.

Provided is a copper foil. The copper foil includes a copper layer and a protective layer disposed on the copper layer, wherein a surface of the protective layer has a maximum height roughness (R.sub.max) of 0.6 m to 3.5 m, a peak density (PD) of 5 to 110, and an oxygen atomic amount of 22 at % (atomic %) to 67 at %.

A steel sheet for cans which exhibits excellent weldability; and a production method therefore include the surface of a steel sheet in order from the steel sheet side, a chromium metal layer and a hydrous chromium oxide layer. The deposited amount of the chromium metal layer is 50-200 mg/m.sup.2. The deposited amount of the hydrous chromium oxide layer in terms of chromium is 3-30 mg/m.sup.2. The chromium metal layer includes: a base part having a thickness of 7.0 nm or higher; and granular protrusions which are on the base part, have a maximum grain size of 200 nm or lower, and have a number density per unit area of at least 30 per m.sup.2.